[v11,1/7] drm: bridge: Cadence: Creat mhdp helper driver

Message ID c4b4b7a56fe79c62f5138593f8048ab5385eac09.1697524277.git.Sandor.yu@nxp.com
State New
Headers
Series Initial support Cadence MHDP8501(HDMI/DP) for i.MX8MQ |

Commit Message

Sandor Yu Oct. 17, 2023, 7:03 a.m. UTC
  MHDP8546 mailbox access functions will be share to other mhdp driver
and Cadence HDP-TX HDMI/DP PHY drivers.
Create a new mhdp helper driver and move all those functions into.

cdns_mhdp_reg_write() is renamed to cdns_mhdp_dp_reg_write(),
because it use the DPTX command ID DPTX_WRITE_REGISTER.

New cdns_mhdp_reg_write() is created with the general command ID
GENERAL_REGISTER_WRITE.

rewrite cdns_mhdp_set_firmware_active() in mhdp8546 core driver,
use cdns_mhdp_mailbox_send() to replace cdns_mhdp_mailbox_write()
same as the other mailbox access functions.

Signed-off-by: Sandor Yu <Sandor.yu@nxp.com>
---
v10->v11:
- rewrite cdns_mhdp_set_firmware_active() in mhdp8546 core driver,
use cdns_mhdp_mailbox_send() to replace cdns_mhdp_mailbox_write()
same as the other mailbox access functions.
- use static for cdns_mhdp_mailbox_write() and cdns_mhdp_mailbox_read()
and remove them from EXPORT_SYMBOL_GPL().

v9->v10:
 *use mhdp helper driver to replace macro functions,
 move maibox access function and mhdp hdmi/dp common API
 functions into the driver.

 drivers/gpu/drm/bridge/cadence/Kconfig        |   4 +
 drivers/gpu/drm/bridge/cadence/Makefile       |   1 +
 .../gpu/drm/bridge/cadence/cdns-mhdp-helper.c | 304 +++++++++++++
 .../drm/bridge/cadence/cdns-mhdp8546-core.c   | 403 +++---------------
 .../drm/bridge/cadence/cdns-mhdp8546-core.h   |  44 +-
 include/drm/bridge/cdns-mhdp-helper.h         |  94 ++++
 6 files changed, 476 insertions(+), 374 deletions(-)
 create mode 100644 drivers/gpu/drm/bridge/cadence/cdns-mhdp-helper.c
 create mode 100644 include/drm/bridge/cdns-mhdp-helper.h
  

Comments

Alexander Stein Oct. 17, 2023, 10:03 a.m. UTC | #1
Hi Sandor,

thanks for the update.

One small typo in the commit message: 'Creat' -> 'Create'

Am Dienstag, 17. Oktober 2023, 09:03:57 CEST schrieb Sandor Yu:
> MHDP8546 mailbox access functions will be share to other mhdp driver
> and Cadence HDP-TX HDMI/DP PHY drivers.
> Create a new mhdp helper driver and move all those functions into.
> 
> cdns_mhdp_reg_write() is renamed to cdns_mhdp_dp_reg_write(),
> because it use the DPTX command ID DPTX_WRITE_REGISTER.
> 
> New cdns_mhdp_reg_write() is created with the general command ID
> GENERAL_REGISTER_WRITE.
> 
> rewrite cdns_mhdp_set_firmware_active() in mhdp8546 core driver,
> use cdns_mhdp_mailbox_send() to replace cdns_mhdp_mailbox_write()
> same as the other mailbox access functions.
> 
> Signed-off-by: Sandor Yu <Sandor.yu@nxp.com>
> ---
> v10->v11:
> - rewrite cdns_mhdp_set_firmware_active() in mhdp8546 core driver,
> use cdns_mhdp_mailbox_send() to replace cdns_mhdp_mailbox_write()
> same as the other mailbox access functions.
> - use static for cdns_mhdp_mailbox_write() and cdns_mhdp_mailbox_read()
> and remove them from EXPORT_SYMBOL_GPL().
> 
> v9->v10:
>  *use mhdp helper driver to replace macro functions,
>  move maibox access function and mhdp hdmi/dp common API
>  functions into the driver.
> 
>  drivers/gpu/drm/bridge/cadence/Kconfig        |   4 +
>  drivers/gpu/drm/bridge/cadence/Makefile       |   1 +
>  .../gpu/drm/bridge/cadence/cdns-mhdp-helper.c | 304 +++++++++++++
>  .../drm/bridge/cadence/cdns-mhdp8546-core.c   | 403 +++---------------
>  .../drm/bridge/cadence/cdns-mhdp8546-core.h   |  44 +-
>  include/drm/bridge/cdns-mhdp-helper.h         |  94 ++++
>  6 files changed, 476 insertions(+), 374 deletions(-)
>  create mode 100644 drivers/gpu/drm/bridge/cadence/cdns-mhdp-helper.c
>  create mode 100644 include/drm/bridge/cdns-mhdp-helper.h
> 
> diff --git a/drivers/gpu/drm/bridge/cadence/Kconfig
> b/drivers/gpu/drm/bridge/cadence/Kconfig index ec35215a20034..0b7b4626a7af0
> 100644
> --- a/drivers/gpu/drm/bridge/cadence/Kconfig
> +++ b/drivers/gpu/drm/bridge/cadence/Kconfig
> @@ -20,6 +20,9 @@ config DRM_CDNS_DSI_J721E
>  	  the routing of the DSS DPI signal to the Cadence DSI.
>  endif
> 
> +config CDNS_MHDP_HELPER
> +	tristate
> +
>  config DRM_CDNS_MHDP8546
>  	tristate "Cadence DPI/DP bridge"
>  	select DRM_DISPLAY_DP_HELPER
> @@ -27,6 +30,7 @@ config DRM_CDNS_MHDP8546
>  	select DRM_DISPLAY_HELPER
>  	select DRM_KMS_HELPER
>  	select DRM_PANEL_BRIDGE
> +	select CDNS_MHDP_HELPER
>  	depends on OF
>  	help
>  	  Support Cadence DPI to DP bridge. This is an internal
> diff --git a/drivers/gpu/drm/bridge/cadence/Makefile
> b/drivers/gpu/drm/bridge/cadence/Makefile index
> c95fd5b81d137..087dc074820d7 100644
> --- a/drivers/gpu/drm/bridge/cadence/Makefile
> +++ b/drivers/gpu/drm/bridge/cadence/Makefile
> @@ -2,6 +2,7 @@
>  obj-$(CONFIG_DRM_CDNS_DSI) += cdns-dsi.o
>  cdns-dsi-y := cdns-dsi-core.o
>  cdns-dsi-$(CONFIG_DRM_CDNS_DSI_J721E) += cdns-dsi-j721e.o
> +obj-$(CONFIG_CDNS_MHDP_HELPER) += cdns-mhdp-helper.o
>  obj-$(CONFIG_DRM_CDNS_MHDP8546) += cdns-mhdp8546.o
>  cdns-mhdp8546-y := cdns-mhdp8546-core.o cdns-mhdp8546-hdcp.o
>  cdns-mhdp8546-$(CONFIG_DRM_CDNS_MHDP8546_J721E) += cdns-mhdp8546-j721e.o
> diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp-helper.c
> b/drivers/gpu/drm/bridge/cadence/cdns-mhdp-helper.c new file mode 100644
> index 0000000000000..8cabd79ad9663
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp-helper.c
> @@ -0,0 +1,304 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2023 NXP Semiconductor, Inc.
> + *
> + */
> +#include <drm/bridge/cdns-mhdp-helper.h>
> +#include <linux/dev_printk.h>
> +#include <linux/module.h>
> +
> +/* Mailbox helper functions */
> +static int cdns_mhdp_mailbox_read(struct cdns_mhdp_base *base)
> +{
> +	int ret, empty;
> +
> +	WARN_ON(!mutex_is_locked(base->mbox_mutex));

Actually this should be moved to cdns_mhdp_mailbox_recv_header() and 
cdns_mhdp_mailbox_recv_data().

> +	ret = readx_poll_timeout(readl, base->regs + CDNS_MAILBOX_EMPTY,
> +				 empty, !empty, MAILBOX_RETRY_US,
> +				 MAILBOX_TIMEOUT_US);
> +	if (ret < 0)
> +		return ret;
> +
> +	return readl(base->regs + CDNS_MAILBOX_RX_DATA) & 0xff;
> +}
> +
> +static int cdns_mhdp_mailbox_write(struct cdns_mhdp_base *base, u8 val)
> +{
> +	int ret, full;
> +
> +	WARN_ON(!mutex_is_locked(base->mbox_mutex));

I think this should be moved to cdns_mhdp_mailbox_send() as well.

> +	ret = readx_poll_timeout(readl, base->regs + CDNS_MAILBOX_FULL,
> +				 full, !full, MAILBOX_RETRY_US,
> +				 MAILBOX_TIMEOUT_US);
> +	if (ret < 0)
> +		return ret;
> +
> +	writel(val, base->regs + CDNS_MAILBOX_TX_DATA);
> +
> +	return 0;
> +}

Nice, much better having these as static now.

> +int cdns_mhdp_mailbox_recv_header(struct cdns_mhdp_base *base,
> +				  u8 module_id, u8 opcode,
> +				  u16 req_size)
> +{
> +	u32 mbox_size, i;
> +	u8 header[4];
> +	int ret;
> +
> +	/* read the header of the message */
> +	for (i = 0; i < sizeof(header); i++) {
> +		ret = cdns_mhdp_mailbox_read(base);
> +		if (ret < 0)
> +			return ret;
> +
> +		header[i] = ret;
> +	}
> +
> +	mbox_size = get_unaligned_be16(header + 2);
> +
> +	if (opcode != header[0] || module_id != header[1] ||
> +	    req_size != mbox_size) {
> +		/*
> +		 * If the message in mailbox is not what we want, we need 
to
> +		 * clear the mailbox by reading its contents.
> +		 */
> +		for (i = 0; i < mbox_size; i++)
> +			if (cdns_mhdp_mailbox_read(base) < 0)
> +				break;
> +
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(cdns_mhdp_mailbox_recv_header);
> +
> +int cdns_mhdp_mailbox_recv_data(struct cdns_mhdp_base *base,
> +				u8 *buff, u16 buff_size)
> +{
> +	u32 i;
> +	int ret;
> +
> +	for (i = 0; i < buff_size; i++) {
> +		ret = cdns_mhdp_mailbox_read(base);
> +		if (ret < 0)
> +			return ret;
> +
> +		buff[i] = ret;
> +	}
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(cdns_mhdp_mailbox_recv_data);
> +
> +int cdns_mhdp_mailbox_send(struct cdns_mhdp_base *base, u8 module_id,
> +			   u8 opcode, u16 size, u8 *message)
> +{
> +	u8 header[4];
> +	int ret, i;
> +
> +	header[0] = opcode;
> +	header[1] = module_id;
> +	put_unaligned_be16(size, header + 2);
> +
> +	for (i = 0; i < sizeof(header); i++) {
> +		ret = cdns_mhdp_mailbox_write(base, header[i]);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	for (i = 0; i < size; i++) {
> +		ret = cdns_mhdp_mailbox_write(base, message[i]);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(cdns_mhdp_mailbox_send);
> +
> +/* General helper functions */
> +int cdns_mhdp_reg_read(struct cdns_mhdp_base *base, u32 addr, u32 *value)
> +{
> +	u8 msg[4], resp[8];
> +	int ret;
> +
> +	put_unaligned_be32(addr, msg);
> +
> +	mutex_lock(base->mbox_mutex);
> +
> +	ret = cdns_mhdp_mailbox_send(base, MB_MODULE_ID_GENERAL,
> +				     GENERAL_REGISTER_READ,
> +				     sizeof(msg), msg);
> +	if (ret)
> +		goto out;
> +
> +	ret = cdns_mhdp_mailbox_recv_header(base, MB_MODULE_ID_GENERAL,
> +					    GENERAL_REGISTER_READ,
> +					    sizeof(resp));
> +	if (ret)
> +		goto out;
> +
> +	ret = cdns_mhdp_mailbox_recv_data(base, resp, sizeof(resp));
> +	if (ret)
> +		goto out;
> +
> +	/* Returned address value should be the same as requested */
> +	if (memcmp(msg, resp, sizeof(msg))) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	*value = get_unaligned_be32(resp + 4);
> +
> +out:
> +	mutex_unlock(base->mbox_mutex);
> +	if (ret) {
> +		dev_err(base->dev, "Failed to read register\n");
> +		*value = 0;
> +	}
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(cdns_mhdp_reg_read);
> +
> +int cdns_mhdp_reg_write(struct cdns_mhdp_base *base, u32 addr, u32 val)
> +{
> +	u8 msg[8];
> +	int ret;
> +
> +	put_unaligned_be32(addr, msg);
> +	put_unaligned_be32(val, msg + 4);
> +
> +	mutex_lock(base->mbox_mutex);
> +
> +	ret = cdns_mhdp_mailbox_send(base, MB_MODULE_ID_GENERAL,
> +				     GENERAL_REGISTER_WRITE,
> +				     sizeof(msg), msg);
> +
> +	mutex_unlock(base->mbox_mutex);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(cdns_mhdp_reg_write);
> +
> +/* DPTX helper functions */
> +int cdns_mhdp_dp_reg_write(struct cdns_mhdp_base *base, u16 addr, u32 val)
> +{
> +	u8 msg[6];
> +	int ret;
> +
> +	put_unaligned_be16(addr, msg);
> +	put_unaligned_be32(val, msg + 2);
> +
> +	mutex_lock(base->mbox_mutex);
> +
> +	ret = cdns_mhdp_mailbox_send(base, MB_MODULE_ID_DP_TX,
> +				     DPTX_WRITE_REGISTER, sizeof(msg), 
msg);
> +
> +	mutex_unlock(base->mbox_mutex);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(cdns_mhdp_dp_reg_write);
> +
> +int cdns_mhdp_dp_reg_write_bit(struct cdns_mhdp_base *base, u16 addr,
> +			       u8 start_bit, u8 bits_no, u32 val)
> +{
> +	u8 field[8];
> +	int ret;
> +
> +	put_unaligned_be16(addr, field);
> +	field[2] = start_bit;
> +	field[3] = bits_no;
> +	put_unaligned_be32(val, field + 4);
> +
> +	mutex_lock(base->mbox_mutex);
> +
> +	ret = cdns_mhdp_mailbox_send(base, MB_MODULE_ID_DP_TX,
> +				     DPTX_WRITE_FIELD, sizeof(field), 
field);
> +
> +	mutex_unlock(base->mbox_mutex);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(cdns_mhdp_dp_reg_write_bit);
> +
> +int cdns_mhdp_dpcd_read(struct cdns_mhdp_base *base,
> +			u32 addr, u8 *data, u16 len)
> +{
> +	u8 msg[5], reg[5];
> +	int ret;
> +
> +	put_unaligned_be16(len, msg);
> +	put_unaligned_be24(addr, msg + 2);
> +
> +	mutex_lock(base->mbox_mutex);
> +
> +	ret = cdns_mhdp_mailbox_send(base, MB_MODULE_ID_DP_TX,
> +				     DPTX_READ_DPCD, sizeof(msg), 
msg);
> +	if (ret)
> +		goto out;
> +
> +	ret = cdns_mhdp_mailbox_recv_header(base, MB_MODULE_ID_DP_TX,
> +					    DPTX_READ_DPCD,
> +					    sizeof(reg) + len);
> +	if (ret)
> +		goto out;
> +
> +	ret = cdns_mhdp_mailbox_recv_data(base, reg, sizeof(reg));
> +	if (ret)
> +		goto out;
> +
> +	ret = cdns_mhdp_mailbox_recv_data(base, data, len);
> +
> +out:
> +	mutex_unlock(base->mbox_mutex);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(cdns_mhdp_dpcd_read);
> +
> +int cdns_mhdp_dpcd_write(struct cdns_mhdp_base *base, u32 addr, u8 value)
> +{
> +	u8 msg[6], reg[5];
> +	int ret;
> +
> +	put_unaligned_be16(1, msg);
> +	put_unaligned_be24(addr, msg + 2);
> +	msg[5] = value;
> +
> +	mutex_lock(base->mbox_mutex);
> +
> +	ret = cdns_mhdp_mailbox_send(base, MB_MODULE_ID_DP_TX,
> +				     DPTX_WRITE_DPCD, sizeof(msg), 
msg);
> +	if (ret)
> +		goto out;
> +
> +	ret = cdns_mhdp_mailbox_recv_header(base, MB_MODULE_ID_DP_TX,
> +					    DPTX_WRITE_DPCD, 
sizeof(reg));
> +	if (ret)
> +		goto out;
> +
> +	ret = cdns_mhdp_mailbox_recv_data(base, reg, sizeof(reg));
> +	if (ret)
> +		goto out;
> +
> +	if (addr != get_unaligned_be24(reg + 2))
> +		ret = -EINVAL;

No need to have the mutex locked while doing this check. This should be moved 
below 'out' label.

> +out:
> +	mutex_unlock(base->mbox_mutex);
> +
> +	if (ret)
> +		dev_err(base->dev, "dpcd write failed: %d\n", ret);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(cdns_mhdp_dpcd_write);
> +
> +MODULE_DESCRIPTION("Cadence MHDP Helper driver");
> +MODULE_AUTHOR("Sandor Yu <Sandor.yu@nxp.com>");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
> b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c index
> 6af565ac307ae..9d9dbb976868c 100644
> --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
> +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
> @@ -73,298 +73,28 @@ static void cdns_mhdp_bridge_hpd_disable(struct
> drm_bridge *bridge) mhdp->regs + CDNS_APB_INT_MASK);
>  }
> 
> -static int cdns_mhdp_mailbox_read(struct cdns_mhdp_device *mhdp)
> -{
> -	int ret, empty;
> -
> -	WARN_ON(!mutex_is_locked(&mhdp->mbox_mutex));
> -
> -	ret = readx_poll_timeout(readl, mhdp->regs + CDNS_MAILBOX_EMPTY,
> -				 empty, !empty, MAILBOX_RETRY_US,
> -				 MAILBOX_TIMEOUT_US);
> -	if (ret < 0)
> -		return ret;
> -
> -	return readl(mhdp->regs + CDNS_MAILBOX_RX_DATA) & 0xff;
> -}
> -
> -static int cdns_mhdp_mailbox_write(struct cdns_mhdp_device *mhdp, u8 val)
> -{
> -	int ret, full;
> -
> -	WARN_ON(!mutex_is_locked(&mhdp->mbox_mutex));
> -
> -	ret = readx_poll_timeout(readl, mhdp->regs + CDNS_MAILBOX_FULL,
> -				 full, !full, MAILBOX_RETRY_US,
> -				 MAILBOX_TIMEOUT_US);
> -	if (ret < 0)
> -		return ret;
> -
> -	writel(val, mhdp->regs + CDNS_MAILBOX_TX_DATA);
> -
> -	return 0;
> -}
> -
> -static int cdns_mhdp_mailbox_recv_header(struct cdns_mhdp_device *mhdp,
> -					 u8 module_id, u8 opcode,
> -					 u16 req_size)
> -{
> -	u32 mbox_size, i;
> -	u8 header[4];
> -	int ret;
> -
> -	/* read the header of the message */
> -	for (i = 0; i < sizeof(header); i++) {
> -		ret = cdns_mhdp_mailbox_read(mhdp);
> -		if (ret < 0)
> -			return ret;
> -
> -		header[i] = ret;
> -	}
> -
> -	mbox_size = get_unaligned_be16(header + 2);
> -
> -	if (opcode != header[0] || module_id != header[1] ||
> -	    req_size != mbox_size) {
> -		/*
> -		 * If the message in mailbox is not what we want, we need 
to
> -		 * clear the mailbox by reading its contents.
> -		 */
> -		for (i = 0; i < mbox_size; i++)
> -			if (cdns_mhdp_mailbox_read(mhdp) < 0)
> -				break;
> -
> -		return -EINVAL;
> -	}
> -
> -	return 0;
> -}
> -
> -static int cdns_mhdp_mailbox_recv_data(struct cdns_mhdp_device *mhdp,
> -				       u8 *buff, u16 buff_size)
> -{
> -	u32 i;
> -	int ret;
> -
> -	for (i = 0; i < buff_size; i++) {
> -		ret = cdns_mhdp_mailbox_read(mhdp);
> -		if (ret < 0)
> -			return ret;
> -
> -		buff[i] = ret;
> -	}
> -
> -	return 0;
> -}
> -
> -static int cdns_mhdp_mailbox_send(struct cdns_mhdp_device *mhdp, u8
> module_id, -				  u8 opcode, u16 size, u8 
*message)
> -{
> -	u8 header[4];
> -	int ret, i;
> -
> -	header[0] = opcode;
> -	header[1] = module_id;
> -	put_unaligned_be16(size, header + 2);
> -
> -	for (i = 0; i < sizeof(header); i++) {
> -		ret = cdns_mhdp_mailbox_write(mhdp, header[i]);
> -		if (ret)
> -			return ret;
> -	}
> -
> -	for (i = 0; i < size; i++) {
> -		ret = cdns_mhdp_mailbox_write(mhdp, message[i]);
> -		if (ret)
> -			return ret;
> -	}
> -
> -	return 0;
> -}
> -
> -static
> -int cdns_mhdp_reg_read(struct cdns_mhdp_device *mhdp, u32 addr, u32 *value)
> -{
> -	u8 msg[4], resp[8];
> -	int ret;
> -
> -	put_unaligned_be32(addr, msg);
> -
> -	mutex_lock(&mhdp->mbox_mutex);
> -
> -	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_GENERAL,
> -				     GENERAL_REGISTER_READ,
> -				     sizeof(msg), msg);
> -	if (ret)
> -		goto out;
> -
> -	ret = cdns_mhdp_mailbox_recv_header(mhdp, MB_MODULE_ID_GENERAL,
> -					    GENERAL_REGISTER_READ,
> -					    sizeof(resp));
> -	if (ret)
> -		goto out;
> -
> -	ret = cdns_mhdp_mailbox_recv_data(mhdp, resp, sizeof(resp));
> -	if (ret)
> -		goto out;
> -
> -	/* Returned address value should be the same as requested */
> -	if (memcmp(msg, resp, sizeof(msg))) {
> -		ret = -EINVAL;
> -		goto out;
> -	}
> -
> -	*value = get_unaligned_be32(resp + 4);
> -
> -out:
> -	mutex_unlock(&mhdp->mbox_mutex);
> -	if (ret) {
> -		dev_err(mhdp->dev, "Failed to read register\n");
> -		*value = 0;
> -	}
> -
> -	return ret;
> -}
> -
> -static
> -int cdns_mhdp_reg_write(struct cdns_mhdp_device *mhdp, u16 addr, u32 val)
> -{
> -	u8 msg[6];
> -	int ret;
> -
> -	put_unaligned_be16(addr, msg);
> -	put_unaligned_be32(val, msg + 2);
> -
> -	mutex_lock(&mhdp->mbox_mutex);
> -
> -	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
> -				     DPTX_WRITE_REGISTER, sizeof(msg), 
msg);
> -
> -	mutex_unlock(&mhdp->mbox_mutex);
> -
> -	return ret;
> -}
> -
>  static
> -int cdns_mhdp_reg_write_bit(struct cdns_mhdp_device *mhdp, u16 addr,
> -			    u8 start_bit, u8 bits_no, u32 val)
> -{
> -	u8 field[8];
> -	int ret;
> -
> -	put_unaligned_be16(addr, field);
> -	field[2] = start_bit;
> -	field[3] = bits_no;
> -	put_unaligned_be32(val, field + 4);
> -
> -	mutex_lock(&mhdp->mbox_mutex);
> -
> -	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
> -				     DPTX_WRITE_FIELD, sizeof(field), 
field);
> -
> -	mutex_unlock(&mhdp->mbox_mutex);
> -
> -	return ret;
> -}
> -
> -static
> -int cdns_mhdp_dpcd_read(struct cdns_mhdp_device *mhdp,
> -			u32 addr, u8 *data, u16 len)
> -{
> -	u8 msg[5], reg[5];
> -	int ret;
> -
> -	put_unaligned_be16(len, msg);
> -	put_unaligned_be24(addr, msg + 2);
> -
> -	mutex_lock(&mhdp->mbox_mutex);
> -
> -	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
> -				     DPTX_READ_DPCD, sizeof(msg), 
msg);
> -	if (ret)
> -		goto out;
> -
> -	ret = cdns_mhdp_mailbox_recv_header(mhdp, MB_MODULE_ID_DP_TX,
> -					    DPTX_READ_DPCD,
> -					    sizeof(reg) + len);
> -	if (ret)
> -		goto out;
> -
> -	ret = cdns_mhdp_mailbox_recv_data(mhdp, reg, sizeof(reg));
> -	if (ret)
> -		goto out;
> -
> -	ret = cdns_mhdp_mailbox_recv_data(mhdp, data, len);
> -
> -out:
> -	mutex_unlock(&mhdp->mbox_mutex);
> -
> -	return ret;
> -}
> -
> -static
> -int cdns_mhdp_dpcd_write(struct cdns_mhdp_device *mhdp, u32 addr, u8 value)
> +int cdns_mhdp_set_firmware_active(struct cdns_mhdp_device *mhdp, bool
> enable) {
> -	u8 msg[6], reg[5];
> +	u8 status;
>  	int ret;
> 
> -	put_unaligned_be16(1, msg);
> -	put_unaligned_be24(addr, msg + 2);
> -	msg[5] = value;
> -
>  	mutex_lock(&mhdp->mbox_mutex);
> 
> -	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
> -				     DPTX_WRITE_DPCD, sizeof(msg), 
msg);
> -	if (ret)
> -		goto out;
> -
> -	ret = cdns_mhdp_mailbox_recv_header(mhdp, MB_MODULE_ID_DP_TX,
> -					    DPTX_WRITE_DPCD, 
sizeof(reg));
> -	if (ret)
> -		goto out;
> +	status = enable ? FW_ACTIVE : FW_STANDBY;

Initialising status can be done outside of the locked mutex.

> -	ret = cdns_mhdp_mailbox_recv_data(mhdp, reg, sizeof(reg));
> +	ret = cdns_mhdp_mailbox_send(&mhdp->base, MB_MODULE_ID_GENERAL,
> +				     GENERAL_MAIN_CONTROL, 
sizeof(status), &status);
>  	if (ret)
>  		goto out;
> 
> -	if (addr != get_unaligned_be24(reg + 2))
> -		ret = -EINVAL;
> -
> -out:
> -	mutex_unlock(&mhdp->mbox_mutex);
> -
> -	if (ret)
> -		dev_err(mhdp->dev, "dpcd write failed: %d\n", ret);
> -	return ret;
> -}
> -
> -static
> -int cdns_mhdp_set_firmware_active(struct cdns_mhdp_device *mhdp, bool
> enable) -{
> -	u8 msg[5];
> -	int ret, i;
> -
> -	msg[0] = GENERAL_MAIN_CONTROL;
> -	msg[1] = MB_MODULE_ID_GENERAL;
> -	msg[2] = 0;
> -	msg[3] = 1;
> -	msg[4] = enable ? FW_ACTIVE : FW_STANDBY;
> -
> -	mutex_lock(&mhdp->mbox_mutex);
> -
> -	for (i = 0; i < sizeof(msg); i++) {
> -		ret = cdns_mhdp_mailbox_write(mhdp, msg[i]);
> -		if (ret)
> -			goto out;
> -	}
> -
> -	/* read the firmware state */
> -	ret = cdns_mhdp_mailbox_recv_data(mhdp, msg, sizeof(msg));
> +	ret = cdns_mhdp_mailbox_recv_header(&mhdp->base, 
MB_MODULE_ID_GENERAL,
> +					    GENERAL_MAIN_CONTROL,
> +					    sizeof(status));
>  	if (ret)
>  		goto out;
> 
> -	ret = 0;
> +	ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, &status, 
sizeof(status));
> 
>  out:
>  	mutex_unlock(&mhdp->mbox_mutex);
> @@ -382,18 +112,18 @@ int cdns_mhdp_get_hpd_status(struct cdns_mhdp_device
> *mhdp)
> 
>  	mutex_lock(&mhdp->mbox_mutex);
> 
> -	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
> +	ret = cdns_mhdp_mailbox_send(&mhdp->base, MB_MODULE_ID_DP_TX,
>  				     DPTX_HPD_STATE, 0, NULL);
>  	if (ret)
>  		goto err_get_hpd;
> 
> -	ret = cdns_mhdp_mailbox_recv_header(mhdp, MB_MODULE_ID_DP_TX,
> +	ret = cdns_mhdp_mailbox_recv_header(&mhdp->base, MB_MODULE_ID_DP_TX,
>  					    DPTX_HPD_STATE,
>  					    sizeof(status));
>  	if (ret)
>  		goto err_get_hpd;
> 
> -	ret = cdns_mhdp_mailbox_recv_data(mhdp, &status, sizeof(status));
> +	ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, &status, 
sizeof(status));
>  	if (ret)
>  		goto err_get_hpd;
> 
> @@ -424,22 +154,22 @@ int cdns_mhdp_get_edid_block(void *data, u8 *edid,
>  		msg[0] = block / 2;
>  		msg[1] = block % 2;
> 
> -		ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
> +		ret = cdns_mhdp_mailbox_send(&mhdp->base, 
MB_MODULE_ID_DP_TX,
>  					     DPTX_GET_EDID, 
sizeof(msg), msg);
>  		if (ret)
>  			continue;
> 
> -		ret = cdns_mhdp_mailbox_recv_header(mhdp, 
MB_MODULE_ID_DP_TX,
> +		ret = cdns_mhdp_mailbox_recv_header(&mhdp->base, 
MB_MODULE_ID_DP_TX,
>  						    DPTX_GET_EDID,
>  						    sizeof(reg) + 
length);
>  		if (ret)
>  			continue;
> 
> -		ret = cdns_mhdp_mailbox_recv_data(mhdp, reg, sizeof(reg));
> +		ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, reg, 
sizeof(reg));
>  		if (ret)
>  			continue;
> 
> -		ret = cdns_mhdp_mailbox_recv_data(mhdp, edid, length);
> +		ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, edid, 
length);
>  		if (ret)
>  			continue;
> 
> @@ -464,17 +194,17 @@ int cdns_mhdp_read_hpd_event(struct cdns_mhdp_device
> *mhdp)
> 
>  	mutex_lock(&mhdp->mbox_mutex);
> 
> -	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
> +	ret = cdns_mhdp_mailbox_send(&mhdp->base, MB_MODULE_ID_DP_TX,
>  				     DPTX_READ_EVENT, 0, NULL);
>  	if (ret)
>  		goto out;
> 
> -	ret = cdns_mhdp_mailbox_recv_header(mhdp, MB_MODULE_ID_DP_TX,
> +	ret = cdns_mhdp_mailbox_recv_header(&mhdp->base, MB_MODULE_ID_DP_TX,
>  					    DPTX_READ_EVENT, 
sizeof(event));
>  	if (ret < 0)
>  		goto out;
> 
> -	ret = cdns_mhdp_mailbox_recv_data(mhdp, &event, sizeof(event));
> +	ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, &event, 
sizeof(event));
>  out:
>  	mutex_unlock(&mhdp->mbox_mutex);
> 
> @@ -512,20 +242,20 @@ int cdns_mhdp_adjust_lt(struct cdns_mhdp_device *mhdp,
> unsigned int nlanes,
> 
>  	mutex_lock(&mhdp->mbox_mutex);
> 
> -	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
> +	ret = cdns_mhdp_mailbox_send(&mhdp->base, MB_MODULE_ID_DP_TX,
>  				     DPTX_ADJUST_LT,
>  				     sizeof(payload), payload);
>  	if (ret)
>  		goto out;
> 
>  	/* Yes, read the DPCD read command response */
> -	ret = cdns_mhdp_mailbox_recv_header(mhdp, MB_MODULE_ID_DP_TX,
> +	ret = cdns_mhdp_mailbox_recv_header(&mhdp->base, MB_MODULE_ID_DP_TX,
>  					    DPTX_READ_DPCD,
>  					    sizeof(hdr) + 
DP_LINK_STATUS_SIZE);
>  	if (ret)
>  		goto out;
> 
> -	ret = cdns_mhdp_mailbox_recv_data(mhdp, hdr, sizeof(hdr));
> +	ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, hdr, sizeof(hdr));
>  	if (ret)
>  		goto out;
> 
> @@ -533,7 +263,7 @@ int cdns_mhdp_adjust_lt(struct cdns_mhdp_device *mhdp,
> unsigned int nlanes, if (addr != DP_LANE0_1_STATUS)
>  		goto out;
> 
> -	ret = cdns_mhdp_mailbox_recv_data(mhdp, link_status,
> +	ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, link_status,
>  					  DP_LINK_STATUS_SIZE);
> 
>  out:
> @@ -847,7 +577,7 @@ static ssize_t cdns_mhdp_transfer(struct drm_dp_aux
> *aux, unsigned int i;
> 
>  		for (i = 0; i < msg->size; ++i) {
> -			ret = cdns_mhdp_dpcd_write(mhdp,
> +			ret = cdns_mhdp_dpcd_write(&mhdp->base,
>  						   msg->address + 
i, buf[i]);
>  			if (!ret)
>  				continue;
> @@ -859,7 +589,7 @@ static ssize_t cdns_mhdp_transfer(struct drm_dp_aux
> *aux, return ret;
>  		}
>  	} else {
> -		ret = cdns_mhdp_dpcd_read(mhdp, msg->address,
> +		ret = cdns_mhdp_dpcd_read(&mhdp->base, msg->address,
>  					  msg->buffer, msg->size);
>  		if (ret) {
>  			dev_err(mhdp->dev,
> @@ -887,12 +617,12 @@ static int cdns_mhdp_link_training_init(struct
> cdns_mhdp_device *mhdp) if (!mhdp->host.scrambler)
>  		reg32 |= CDNS_PHY_SCRAMBLER_BYPASS;
> 
> -	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_PHY_CONFIG, reg32);
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_PHY_CONFIG, reg32);
> 
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_ENHNCD,
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_ENHNCD,
>  			    mhdp->sink.enhanced & mhdp->host.enhanced);
> 
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_LANE_EN,
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_LANE_EN,
>  			    CDNS_DP_LANE_EN_LANES(mhdp-
>link.num_lanes));
> 
>  	cdns_mhdp_link_configure(&mhdp->aux, &mhdp->link);
> @@ -913,7 +643,7 @@ static int cdns_mhdp_link_training_init(struct
> cdns_mhdp_device *mhdp) return ret;
>  	}
> 
> -	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_PHY_CONFIG,
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_PHY_CONFIG,
>  			    CDNS_PHY_COMMON_CONFIG |
>  			    CDNS_PHY_TRAINING_EN |
>  			    CDNS_PHY_TRAINING_TYPE(1) |
> @@ -1058,7 +788,7 @@ static bool cdns_mhdp_link_training_channel_eq(struct
> cdns_mhdp_device *mhdp, CDNS_PHY_TRAINING_TYPE(eq_tps);
>  	if (eq_tps != 4)
>  		reg32 |= CDNS_PHY_SCRAMBLER_BYPASS;
> -	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_PHY_CONFIG, reg32);
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_PHY_CONFIG, reg32);
> 
>  	drm_dp_dpcd_writeb(&mhdp->aux, DP_TRAINING_PATTERN_SET,
>  			   (eq_tps != 4) ? eq_tps | 
DP_LINK_SCRAMBLING_DISABLE :
> @@ -1322,7 +1052,7 @@ static int cdns_mhdp_link_training(struct
> cdns_mhdp_device *mhdp, mhdp->host.scrambler ? 0 :
>  			   DP_LINK_SCRAMBLING_DISABLE);
> 
> -	ret = cdns_mhdp_reg_read(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, 
&reg32);
> +	ret = cdns_mhdp_reg_read(&mhdp->base, CDNS_DP_FRAMER_GLOBAL_CONFIG,
> &reg32); if (ret < 0) {
>  		dev_err(mhdp->dev,
>  			"Failed to read CDNS_DP_FRAMER_GLOBAL_CONFIG 
%d\n",
> @@ -1333,13 +1063,13 @@ static int cdns_mhdp_link_training(struct
> cdns_mhdp_device *mhdp, reg32 |= CDNS_DP_NUM_LANES(mhdp->link.num_lanes);
>  	reg32 |= CDNS_DP_WR_FAILING_EDGE_VSYNC;
>  	reg32 |= CDNS_DP_FRAMER_EN;
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, reg32);
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_FRAMER_GLOBAL_CONFIG, 
reg32);
> 
>  	/* Reset PHY config */
>  	reg32 = CDNS_PHY_COMMON_CONFIG | CDNS_PHY_TRAINING_TYPE(1);
>  	if (!mhdp->host.scrambler)
>  		reg32 |= CDNS_PHY_SCRAMBLER_BYPASS;
> -	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_PHY_CONFIG, reg32);
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_PHY_CONFIG, reg32);
> 
>  	return 0;
>  err:
> @@ -1347,7 +1077,7 @@ static int cdns_mhdp_link_training(struct
> cdns_mhdp_device *mhdp, reg32 = CDNS_PHY_COMMON_CONFIG |
> CDNS_PHY_TRAINING_TYPE(1);
>  	if (!mhdp->host.scrambler)
>  		reg32 |= CDNS_PHY_SCRAMBLER_BYPASS;
> -	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_PHY_CONFIG, reg32);
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_PHY_CONFIG, reg32);
> 
>  	drm_dp_dpcd_writeb(&mhdp->aux, DP_TRAINING_PATTERN_SET,
>  			   DP_TRAINING_PATTERN_DISABLE);
> @@ -1461,7 +1191,7 @@ static int cdns_mhdp_link_up(struct cdns_mhdp_device
> *mhdp) mhdp->link.num_lanes = cdns_mhdp_max_num_lanes(mhdp);
> 
>  	/* Disable framer for link training */
> -	err = cdns_mhdp_reg_read(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, &resp);
> +	err = cdns_mhdp_reg_read(&mhdp->base, CDNS_DP_FRAMER_GLOBAL_CONFIG,
> &resp); if (err < 0) {
>  		dev_err(mhdp->dev,
>  			"Failed to read CDNS_DP_FRAMER_GLOBAL_CONFIG 
%d\n",
> @@ -1470,7 +1200,7 @@ static int cdns_mhdp_link_up(struct cdns_mhdp_device
> *mhdp) }
> 
>  	resp &= ~CDNS_DP_FRAMER_EN;
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, resp);
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_FRAMER_GLOBAL_CONFIG, 
resp);
> 
>  	/* Spread AMP if required, enable 8b/10b coding */
>  	amp[0] = cdns_mhdp_get_ssc_supported(mhdp) ? DP_SPREAD_AMP_0_5 : 0;
> @@ -1837,7 +1567,7 @@ static void cdns_mhdp_configure_video(struct
> cdns_mhdp_device *mhdp, if (mode->flags & DRM_MODE_FLAG_INTERLACE)
>  		bnd_hsync2vsync |= CDNS_IP_DET_INTERLACE_FORMAT;
> 
> -	cdns_mhdp_reg_write(mhdp, CDNS_BND_HSYNC2VSYNC(stream_id),
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_BND_HSYNC2VSYNC(stream_id),
>  			    bnd_hsync2vsync);
> 
>  	hsync2vsync_pol_ctrl = 0;
> @@ -1845,10 +1575,10 @@ static void cdns_mhdp_configure_video(struct
> cdns_mhdp_device *mhdp, hsync2vsync_pol_ctrl |=
> CDNS_H2V_HSYNC_POL_ACTIVE_LOW;
>  	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
>  		hsync2vsync_pol_ctrl |= CDNS_H2V_VSYNC_POL_ACTIVE_LOW;
> -	cdns_mhdp_reg_write(mhdp, CDNS_HSYNC2VSYNC_POL_CTRL(stream_id),
> +	cdns_mhdp_reg_write(&mhdp->base, 
CDNS_HSYNC2VSYNC_POL_CTRL(stream_id),
>  			    hsync2vsync_pol_ctrl);
> 
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_PXL_REPR(stream_id), 
pxl_repr);
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_FRAMER_PXL_REPR(stream_id),
> pxl_repr);
> 
>  	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
>  		dp_framer_sp |= CDNS_DP_FRAMER_INTERLACE;
> @@ -1856,19 +1586,19 @@ static void cdns_mhdp_configure_video(struct
> cdns_mhdp_device *mhdp, dp_framer_sp |= CDNS_DP_FRAMER_HSYNC_POL_LOW;
>  	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
>  		dp_framer_sp |= CDNS_DP_FRAMER_VSYNC_POL_LOW;
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_SP(stream_id), 
dp_framer_sp);
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_FRAMER_SP(stream_id),
> dp_framer_sp);
> 
>  	front_porch = mode->crtc_hsync_start - mode->crtc_hdisplay;
>  	back_porch = mode->crtc_htotal - mode->crtc_hsync_end;
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRONT_BACK_PORCH(stream_id),
> +	cdns_mhdp_reg_write(&mhdp->base, 
CDNS_DP_FRONT_BACK_PORCH(stream_id),
>  			    CDNS_DP_FRONT_PORCH(front_porch) |
>  			    CDNS_DP_BACK_PORCH(back_porch));
> 
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_BYTE_COUNT(stream_id),
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_BYTE_COUNT(stream_id),
>  			    mode->crtc_hdisplay * bpp / 8);
> 
>  	msa_h0 = mode->crtc_htotal - mode->crtc_hsync_start;
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_HORIZONTAL_0(stream_id),
> +	cdns_mhdp_reg_write(&mhdp->base, 
CDNS_DP_MSA_HORIZONTAL_0(stream_id),
>  			    CDNS_DP_MSAH0_H_TOTAL(mode->crtc_htotal) |
>  			    CDNS_DP_MSAH0_HSYNC_START(msa_h0));
> 
> @@ -1877,11 +1607,11 @@ static void cdns_mhdp_configure_video(struct
> cdns_mhdp_device *mhdp, CDNS_DP_MSAH1_HDISP_WIDTH(mode->crtc_hdisplay);
>  	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
>  		msa_horizontal_1 |= CDNS_DP_MSAH1_HSYNC_POL_LOW;
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_HORIZONTAL_1(stream_id),
> +	cdns_mhdp_reg_write(&mhdp->base, 
CDNS_DP_MSA_HORIZONTAL_1(stream_id),
>  			    msa_horizontal_1);
> 
>  	msa_v0 = mode->crtc_vtotal - mode->crtc_vsync_start;
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_VERTICAL_0(stream_id),
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_MSA_VERTICAL_0(stream_id),
>  			    CDNS_DP_MSAV0_V_TOTAL(mode->crtc_vtotal) |
>  			    CDNS_DP_MSAV0_VSYNC_START(msa_v0));
> 
> @@ -1890,7 +1620,7 @@ static void cdns_mhdp_configure_video(struct
> cdns_mhdp_device *mhdp, CDNS_DP_MSAV1_VDISP_WIDTH(mode->crtc_vdisplay);
>  	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
>  		msa_vertical_1 |= CDNS_DP_MSAV1_VSYNC_POL_LOW;
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_VERTICAL_1(stream_id),
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_MSA_VERTICAL_1(stream_id),
>  			    msa_vertical_1);
> 
>  	if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
> @@ -1902,14 +1632,14 @@ static void cdns_mhdp_configure_video(struct
> cdns_mhdp_device *mhdp, if (pxlfmt == DRM_COLOR_FORMAT_YCBCR420)
>  		misc1 = CDNS_DP_TEST_VSC_SDP;
> 
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_MISC(stream_id),
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_MSA_MISC(stream_id),
>  			    misc0 | (misc1 << 8));
> 
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_HORIZONTAL(stream_id),
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_HORIZONTAL(stream_id),
>  			    CDNS_DP_H_HSYNC_WIDTH(hsync) |
>  			    CDNS_DP_H_H_TOTAL(mode->crtc_hdisplay));
> 
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_VERTICAL_0(stream_id),
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_VERTICAL_0(stream_id),
>  			    CDNS_DP_V0_VHEIGHT(mode->crtc_vdisplay) |
>  			    CDNS_DP_V0_VSTART(msa_v0));
> 
> @@ -1918,13 +1648,13 @@ static void cdns_mhdp_configure_video(struct
> cdns_mhdp_device *mhdp, mode->crtc_vtotal % 2 == 0)
>  		dp_vertical_1 |= CDNS_DP_V1_VTOTAL_EVEN;
> 
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_VERTICAL_1(stream_id), 
dp_vertical_1);
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_VERTICAL_1(stream_id),
> dp_vertical_1);
> 
> -	cdns_mhdp_reg_write_bit(mhdp, CDNS_DP_VB_ID(stream_id), 2, 1,
> -				(mode->flags & 
DRM_MODE_FLAG_INTERLACE) ?
> -				CDNS_DP_VB_ID_INTERLACED : 0);
> +	cdns_mhdp_dp_reg_write_bit(&mhdp->base, CDNS_DP_VB_ID(stream_id), 2, 
1,
> +				   (mode->flags & 
DRM_MODE_FLAG_INTERLACE) ?
> +				   CDNS_DP_VB_ID_INTERLACED : 0);
> 
> -	ret = cdns_mhdp_reg_read(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, 
&framer);
> +	ret = cdns_mhdp_reg_read(&mhdp->base, CDNS_DP_FRAMER_GLOBAL_CONFIG,
> &framer); if (ret < 0) {
>  		dev_err(mhdp->dev,
>  			"Failed to read CDNS_DP_FRAMER_GLOBAL_CONFIG 
%d\n",
> @@ -1933,7 +1663,7 @@ static void cdns_mhdp_configure_video(struct
> cdns_mhdp_device *mhdp, }
>  	framer |= CDNS_DP_FRAMER_EN;
>  	framer &= ~CDNS_DP_NO_VIDEO_MODE;
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, framer);
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_FRAMER_GLOBAL_CONFIG, 
framer);
>  }
> 
>  static void cdns_mhdp_sst_enable(struct cdns_mhdp_device *mhdp,
> @@ -1966,15 +1696,15 @@ static void cdns_mhdp_sst_enable(struct
> cdns_mhdp_device *mhdp,
> 
>  	mhdp->stream_id = 0;
> 
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_TU,
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_FRAMER_TU,
>  			    CDNS_DP_FRAMER_TU_VS(vs) |
>  			    CDNS_DP_FRAMER_TU_SIZE(tu_size) |
>  			    CDNS_DP_FRAMER_TU_CNT_RST_EN);
> 
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_LINE_THRESH(0),
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_LINE_THRESH(0),
>  			    line_thresh & GENMASK(5, 0));
> 
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_STREAM_CONFIG_2(0),
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_STREAM_CONFIG_2(0),
>  			    CDNS_DP_SC2_TU_VS_DIFF((tu_size - vs > 3) ?
>  						   0 : tu_size - 
vs));
> 
> @@ -2009,13 +1739,13 @@ static void cdns_mhdp_atomic_enable(struct
> drm_bridge *bridge, mhdp->info->ops->enable(mhdp);
> 
>  	/* Enable VIF clock for stream 0 */
> -	ret = cdns_mhdp_reg_read(mhdp, CDNS_DPTX_CAR, &resp);
> +	ret = cdns_mhdp_reg_read(&mhdp->base, CDNS_DPTX_CAR, &resp);
>  	if (ret < 0) {
>  		dev_err(mhdp->dev, "Failed to read CDNS_DPTX_CAR %d\n", 
ret);
>  		goto out;
>  	}
> 
> -	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_CAR,
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_CAR,
>  			    resp | CDNS_VIF_CLK_EN | CDNS_VIF_CLK_RSTN);
> 
>  	connector = drm_atomic_get_new_connector_for_encoder(state,
> @@ -2083,16 +1813,16 @@ static void cdns_mhdp_atomic_disable(struct
> drm_bridge *bridge, cdns_mhdp_hdcp_disable(mhdp);
> 
>  	mhdp->bridge_enabled = false;
> -	cdns_mhdp_reg_read(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, &resp);
> +	cdns_mhdp_reg_read(&mhdp->base, CDNS_DP_FRAMER_GLOBAL_CONFIG, 
&resp);
>  	resp &= ~CDNS_DP_FRAMER_EN;
>  	resp |= CDNS_DP_NO_VIDEO_MODE;
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, resp);
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_FRAMER_GLOBAL_CONFIG, 
resp);
> 
>  	cdns_mhdp_link_down(mhdp);
> 
>  	/* Disable VIF clock for stream 0 */
> -	cdns_mhdp_reg_read(mhdp, CDNS_DPTX_CAR, &resp);
> -	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_CAR,
> +	cdns_mhdp_reg_read(&mhdp->base, CDNS_DPTX_CAR, &resp);
> +	cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_CAR,
>  			    resp & ~(CDNS_VIF_CLK_EN | 
CDNS_VIF_CLK_RSTN));
> 
>  	if (mhdp->info && mhdp->info->ops && mhdp->info->ops->disable)
> @@ -2502,6 +2232,11 @@ static int cdns_mhdp_probe(struct platform_device
> *pdev)
> 
>  	platform_set_drvdata(pdev, mhdp);
> 
> +	/* init base struct for access mailbox  */
> +	mhdp->base.dev = mhdp->dev;
> +	mhdp->base.regs = mhdp->regs;
> +	mhdp->base.mbox_mutex = &mhdp->mbox_mutex;
> +
>  	mhdp->info = of_device_get_match_data(dev);
> 
>  	clk_prepare_enable(clk);
> diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h
> b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h index
> bad2fc0c73066..f08db38c82bbd 100644
> --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h
> +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h
> @@ -15,6 +15,7 @@
>  #include <linux/mutex.h>
>  #include <linux/spinlock.h>
> 
> +#include <drm/bridge/cdns-mhdp-helper.h>
>  #include <drm/display/drm_dp_helper.h>
>  #include <drm/drm_bridge.h>
>  #include <drm/drm_connector.h>
> @@ -27,10 +28,6 @@ struct phy;
>  #define CDNS_APB_CTRL				0x00000
>  #define CDNS_CPU_STALL				BIT(3)
> 
> -#define CDNS_MAILBOX_FULL			0x00008
> -#define CDNS_MAILBOX_EMPTY			0x0000c
> -#define CDNS_MAILBOX_TX_DATA			0x00010
> -#define CDNS_MAILBOX_RX_DATA			0x00014
>  #define CDNS_KEEP_ALIVE				0x00018
>  #define CDNS_KEEP_ALIVE_MASK			GENMASK(7, 0)
> 
> @@ -198,45 +195,10 @@ struct phy;
>  #define CDNS_DP_BYTE_COUNT(s)			
(CDNS_DPTX_STREAM(s) + 0x7c)
>  #define CDNS_DP_BYTE_COUNT_BYTES_IN_CHUNK_SHIFT	16
> 
> -/* mailbox */
> -#define MAILBOX_RETRY_US			1000
> -#define MAILBOX_TIMEOUT_US			2000000
> -
> -#define MB_OPCODE_ID				0
> -#define MB_MODULE_ID				1
> -#define MB_SIZE_MSB_ID				2
> -#define MB_SIZE_LSB_ID				3
> -#define MB_DATA_ID				4
> -
> -#define MB_MODULE_ID_DP_TX			0x01
> -#define MB_MODULE_ID_HDCP_TX			0x07
> -#define MB_MODULE_ID_HDCP_RX			0x08
> -#define MB_MODULE_ID_HDCP_GENERAL		0x09
> -#define MB_MODULE_ID_GENERAL			0x0a
> -
> -/* firmware and opcodes */
> +/* firmware */
>  #define FW_NAME					"cadence/
mhdp8546.bin"
>  #define CDNS_MHDP_IMEM				0x10000
> 
> -#define GENERAL_MAIN_CONTROL			0x01
> -#define GENERAL_TEST_ECHO			0x02
> -#define GENERAL_BUS_SETTINGS			0x03
> -#define GENERAL_TEST_ACCESS			0x04
> -#define GENERAL_REGISTER_READ			0x07
> -
> -#define DPTX_SET_POWER_MNG			0x00
> -#define DPTX_GET_EDID				0x02
> -#define DPTX_READ_DPCD				0x03
> -#define DPTX_WRITE_DPCD				0x04
> -#define DPTX_ENABLE_EVENT			0x05
> -#define DPTX_WRITE_REGISTER			0x06
> -#define DPTX_READ_REGISTER			0x07
> -#define DPTX_WRITE_FIELD			0x08
> -#define DPTX_READ_EVENT				0x0a
> -#define DPTX_GET_LAST_AUX_STAUS			0x0e
> -#define DPTX_HPD_STATE				0x11
> -#define DPTX_ADJUST_LT				0x12
> -
>  #define FW_STANDBY				0
>  #define FW_ACTIVE				1
> 
> @@ -352,6 +314,8 @@ struct cdns_mhdp_hdcp {
>  };
> 
>  struct cdns_mhdp_device {
> +	struct cdns_mhdp_base base;
> +
>  	void __iomem *regs;
>  	void __iomem *sapb_regs;
>  	void __iomem *j721e_regs;
> diff --git a/include/drm/bridge/cdns-mhdp-helper.h
> b/include/drm/bridge/cdns-mhdp-helper.h new file mode 100644
> index 0000000000000..477e67601ee5f
> --- /dev/null
> +++ b/include/drm/bridge/cdns-mhdp-helper.h
> @@ -0,0 +1,94 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2023 NXP Semiconductor, Inc.
> + */
> +#ifndef __CDNS_MHDP_HELPER_H__
> +#define __CDNS_MHDP_HELPER_H__
> +
> +#include <asm/unaligned.h>
> +#include <linux/iopoll.h>
> +
> +/* mailbox regs offset */
> +#define CDNS_MAILBOX_FULL			0x00008
> +#define CDNS_MAILBOX_EMPTY			0x0000c
> +#define CDNS_MAILBOX_TX_DATA			0x00010
> +#define CDNS_MAILBOX_RX_DATA			0x00014
> +
> +#define MAILBOX_RETRY_US			1000
> +#define MAILBOX_TIMEOUT_US			2000000
> +
> +/* Module ID Code */
> +#define MB_MODULE_ID_DP_TX			0x01
> +#define MB_MODULE_ID_HDMI_TX			0x03
> +#define MB_MODULE_ID_HDCP_TX			0x07
> +#define MB_MODULE_ID_HDCP_RX			0x08
> +#define MB_MODULE_ID_HDCP_GENERAL		0x09
> +#define MB_MODULE_ID_GENERAL			0x0A
> +
> +/* General Commands */
> +#define GENERAL_MAIN_CONTROL			0x01
> +#define GENERAL_TEST_ECHO			0x02
> +#define GENERAL_BUS_SETTINGS			0x03
> +#define GENERAL_TEST_ACCESS			0x04
> +#define GENERAL_REGISTER_WRITE			0x05
> +#define GENERAL_WRITE_FIELD			0x06
> +#define GENERAL_REGISTER_READ			0x07
> +#define GENERAL_GET_HPD_STATE			0x11
> +
> +/* DPTX Commands */
> +#define DPTX_SET_POWER_MNG			0x00
> +#define DPTX_SET_HOST_CAPABILITIES		0x01
> +#define DPTX_GET_EDID				0x02
> +#define DPTX_READ_DPCD				0x03
> +#define DPTX_WRITE_DPCD				0x04
> +#define DPTX_ENABLE_EVENT			0x05
> +#define DPTX_WRITE_REGISTER			0x06
> +#define DPTX_READ_REGISTER			0x07
> +#define DPTX_WRITE_FIELD			0x08
> +#define DPTX_TRAINING_CONTROL			0x09
> +#define DPTX_READ_EVENT				0x0a
> +#define DPTX_READ_LINK_STAT			0x0b
> +#define DPTX_SET_VIDEO				0x0c
> +#define DPTX_SET_AUDIO				0x0d
> +#define DPTX_GET_LAST_AUX_STAUS			0x0e
> +#define DPTX_SET_LINK_BREAK_POINT		0x0f
> +#define DPTX_FORCE_LANES			0x10
> +#define DPTX_HPD_STATE				0x11
> +#define DPTX_ADJUST_LT				0x12
> +
> +/* HDMI TX Commands */
> +#define HDMI_TX_READ				0x00
> +#define HDMI_TX_WRITE				0x01
> +#define HDMI_TX_UPDATE_READ			0x02
> +#define HDMI_TX_EDID				0x03
> +#define HDMI_TX_EVENTS				0x04
> +#define HDMI_TX_HPD_STATUS			0x05
> +
> +struct cdns_mhdp_base {
> +	struct device *dev;
> +	void __iomem *regs;
> +	/* protect mailbox communications with the firmware */
> +	struct mutex *mbox_mutex;
> +};
> +
> +/* Mailbox helper functions */
> +int cdns_mhdp_mailbox_send(struct cdns_mhdp_base *base, u8 module_id,
> +			   u8 opcode, u16 size, u8 *message);

Any reason to move the declaration for send before recv? It seems reasonable 
to have the in alphabetical order.

> +int cdns_mhdp_mailbox_recv_header(struct cdns_mhdp_base *base,
> +				  u8 module_id, u8 opcode, u16 
req_size);
> +int cdns_mhdp_mailbox_recv_data(struct cdns_mhdp_base *base,
> +				u8 *buff, u16 buff_size);

AFAICS while calling a sequence of these 3 functions mhdp->mbox_mutex is 
locked. This should be noted here.

Best regards,
Alexander

> +/* General commands helper functions */
> +int cdns_mhdp_reg_read(struct cdns_mhdp_base *base, u32 addr, u32 *value);
> +int cdns_mhdp_reg_write(struct cdns_mhdp_base *base, u32 addr, u32 val);
> +
> +/* DPTX commands helper functions */
> +int cdns_mhdp_dp_reg_write(struct cdns_mhdp_base *base, u16 addr, u32 val);
> +int cdns_mhdp_dp_reg_write_bit(struct cdns_mhdp_base *base, u16 addr, +	
		
>       u8 start_bit, u8 bits_no, u32 val);
> +int cdns_mhdp_dpcd_read(struct cdns_mhdp_base *base,
> +			u32 addr, u8 *data, u16 len);
> +int cdns_mhdp_dpcd_write(struct cdns_mhdp_base *base, u32 addr, u8 value);
> +
> +#endif /* __CDNS_MHDP_HELPER_H__ */
  
Sandor Yu Jan. 5, 2024, 3:20 a.m. UTC | #2
Hi Alexander,

Thanks for your comments,

>
> Hi Sandor,
>
> thanks for the update.
>
> One small typo in the commit message: 'Creat' -> 'Create'
>
> Am Dienstag, 17. Oktober 2023, 09:03:57 CEST schrieb Sandor Yu:
> > MHDP8546 mailbox access functions will be share to other mhdp driver
> > and Cadence HDP-TX HDMI/DP PHY drivers.
> > Create a new mhdp helper driver and move all those functions into.
> >
> > cdns_mhdp_reg_write() is renamed to cdns_mhdp_dp_reg_write(), because
> > it use the DPTX command ID DPTX_WRITE_REGISTER.
> >
> > New cdns_mhdp_reg_write() is created with the general command ID
> > GENERAL_REGISTER_WRITE.
> >
> > rewrite cdns_mhdp_set_firmware_active() in mhdp8546 core driver, use
> > cdns_mhdp_mailbox_send() to replace cdns_mhdp_mailbox_write() same
> as
> > the other mailbox access functions.
> >
> > Signed-off-by: Sandor Yu <Sandor.yu@nxp.com>
> > ---
> > v10->v11:
> > - rewrite cdns_mhdp_set_firmware_active() in mhdp8546 core driver, use
> > cdns_mhdp_mailbox_send() to replace cdns_mhdp_mailbox_write() same
> as
> > the other mailbox access functions.
> > - use static for cdns_mhdp_mailbox_write() and
> > cdns_mhdp_mailbox_read() and remove them from
> EXPORT_SYMBOL_GPL().
> >
> > v9->v10:
> >  *use mhdp helper driver to replace macro functions,  move maibox
> > access function and mhdp hdmi/dp common API  functions into the
> > driver.
> >
> >  drivers/gpu/drm/bridge/cadence/Kconfig        |   4 +
> >  drivers/gpu/drm/bridge/cadence/Makefile       |   1 +
> >  .../gpu/drm/bridge/cadence/cdns-mhdp-helper.c | 304 +++++++++++++
> >  .../drm/bridge/cadence/cdns-mhdp8546-core.c   | 403 +++---------------
> >  .../drm/bridge/cadence/cdns-mhdp8546-core.h   |  44 +-
> >  include/drm/bridge/cdns-mhdp-helper.h         |  94 ++++
> >  6 files changed, 476 insertions(+), 374 deletions(-)  create mode
> > 100644 drivers/gpu/drm/bridge/cadence/cdns-mhdp-helper.c
> >  create mode 100644 include/drm/bridge/cdns-mhdp-helper.h
> >
> > diff --git a/drivers/gpu/drm/bridge/cadence/Kconfig
> > b/drivers/gpu/drm/bridge/cadence/Kconfig index
> > ec35215a20034..0b7b4626a7af0
> > 100644
> > --- a/drivers/gpu/drm/bridge/cadence/Kconfig
> > +++ b/drivers/gpu/drm/bridge/cadence/Kconfig
> > @@ -20,6 +20,9 @@ config DRM_CDNS_DSI_J721E
> >         the routing of the DSS DPI signal to the Cadence DSI.
> >  endif
> >
> > +config CDNS_MHDP_HELPER
> > +     tristate
> > +
> >  config DRM_CDNS_MHDP8546
> >       tristate "Cadence DPI/DP bridge"
> >       select DRM_DISPLAY_DP_HELPER
> > @@ -27,6 +30,7 @@ config DRM_CDNS_MHDP8546
> >       select DRM_DISPLAY_HELPER
> >       select DRM_KMS_HELPER
> >       select DRM_PANEL_BRIDGE
> > +     select CDNS_MHDP_HELPER
> >       depends on OF
> >       help
> >         Support Cadence DPI to DP bridge. This is an internal diff
> > --git a/drivers/gpu/drm/bridge/cadence/Makefile
> > b/drivers/gpu/drm/bridge/cadence/Makefile index
> > c95fd5b81d137..087dc074820d7 100644
> > --- a/drivers/gpu/drm/bridge/cadence/Makefile
> > +++ b/drivers/gpu/drm/bridge/cadence/Makefile
> > @@ -2,6 +2,7 @@
> >  obj-$(CONFIG_DRM_CDNS_DSI) += cdns-dsi.o  cdns-dsi-y :=
> > cdns-dsi-core.o
> >  cdns-dsi-$(CONFIG_DRM_CDNS_DSI_J721E) += cdns-dsi-j721e.o
> > +obj-$(CONFIG_CDNS_MHDP_HELPER) += cdns-mhdp-helper.o
> >  obj-$(CONFIG_DRM_CDNS_MHDP8546) += cdns-mhdp8546.o
> cdns-mhdp8546-y
> > := cdns-mhdp8546-core.o cdns-mhdp8546-hdcp.o
> >  cdns-mhdp8546-$(CONFIG_DRM_CDNS_MHDP8546_J721E) +=
> > cdns-mhdp8546-j721e.o diff --git
> > a/drivers/gpu/drm/bridge/cadence/cdns-mhdp-helper.c
> > b/drivers/gpu/drm/bridge/cadence/cdns-mhdp-helper.c new file mode
> > 100644 index 0000000000000..8cabd79ad9663
> > --- /dev/null
> > +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp-helper.c
> > @@ -0,0 +1,304 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Copyright (C) 2023 NXP Semiconductor, Inc.
> > + *
> > + */
> > +#include <drm/bridge/cdns-mhdp-helper.h> #include
> > +<linux/dev_printk.h> #include <linux/module.h>
> > +
> > +/* Mailbox helper functions */
> > +static int cdns_mhdp_mailbox_read(struct cdns_mhdp_base *base) {
> > +     int ret, empty;
> > +
> > +     WARN_ON(!mutex_is_locked(base->mbox_mutex));
>
> Actually this should be moved to cdns_mhdp_mailbox_recv_header() and
> cdns_mhdp_mailbox_recv_data().

Yes, it could be moved to cdns_mhdp_mailbox_send() only and removed from cdns_mhdp_mailbox_read()
cdns_mhdp_mailbox_write(), but those mailbox access functions are move from cdns-mhdp8546-core.c,
I think it had better keep the same implement in this patch set. Another patch may need to fix it.

>
> > +     ret = readx_poll_timeout(readl, base->regs +
> CDNS_MAILBOX_EMPTY,
> > +                              empty, !empty, MAILBOX_RETRY_US,
> > +                              MAILBOX_TIMEOUT_US);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     return readl(base->regs + CDNS_MAILBOX_RX_DATA) & 0xff; }
> > +
> > +static int cdns_mhdp_mailbox_write(struct cdns_mhdp_base *base, u8
> > +val) {
> > +     int ret, full;
> > +
> > +     WARN_ON(!mutex_is_locked(base->mbox_mutex));
>
> I think this should be moved to cdns_mhdp_mailbox_send() as well.

Same reply as above.

>
> > +     ret = readx_poll_timeout(readl, base->regs + CDNS_MAILBOX_FULL,
> > +                              full, !full, MAILBOX_RETRY_US,
> > +                              MAILBOX_TIMEOUT_US);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     writel(val, base->regs + CDNS_MAILBOX_TX_DATA);
> > +
> > +     return 0;
> > +}
>
> Nice, much better having these as static now.

Thanks.

>
> > +int cdns_mhdp_mailbox_recv_header(struct cdns_mhdp_base *base,
> > +                               u8 module_id, u8 opcode,
> > +                               u16 req_size) {
> > +     u32 mbox_size, i;
> > +     u8 header[4];
> > +     int ret;
> > +
> > +     /* read the header of the message */
> > +     for (i = 0; i < sizeof(header); i++) {
> > +             ret = cdns_mhdp_mailbox_read(base);
> > +             if (ret < 0)
> > +                     return ret;
> > +
> > +             header[i] = ret;
> > +     }
> > +
> > +     mbox_size = get_unaligned_be16(header + 2);
> > +
> > +     if (opcode != header[0] || module_id != header[1] ||
> > +         req_size != mbox_size) {
> > +             /*
> > +              * If the message in mailbox is not what we want, we
> > + need
> to
> > +              * clear the mailbox by reading its contents.
> > +              */
> > +             for (i = 0; i < mbox_size; i++)
> > +                     if (cdns_mhdp_mailbox_read(base) < 0)
> > +                             break;
> > +
> > +             return -EINVAL;
> > +     }
> > +
> > +     return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(cdns_mhdp_mailbox_recv_header);
> > +
> > +int cdns_mhdp_mailbox_recv_data(struct cdns_mhdp_base *base,
> > +                             u8 *buff, u16 buff_size) {
> > +     u32 i;
> > +     int ret;
> > +
> > +     for (i = 0; i < buff_size; i++) {
> > +             ret = cdns_mhdp_mailbox_read(base);
> > +             if (ret < 0)
> > +                     return ret;
> > +
> > +             buff[i] = ret;
> > +     }
> > +
> > +     return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(cdns_mhdp_mailbox_recv_data);
> > +
> > +int cdns_mhdp_mailbox_send(struct cdns_mhdp_base *base, u8
> module_id,
> > +                        u8 opcode, u16 size, u8 *message) {
> > +     u8 header[4];
> > +     int ret, i;
> > +
> > +     header[0] = opcode;
> > +     header[1] = module_id;
> > +     put_unaligned_be16(size, header + 2);
> > +
> > +     for (i = 0; i < sizeof(header); i++) {
> > +             ret = cdns_mhdp_mailbox_write(base, header[i]);
> > +             if (ret)
> > +                     return ret;
> > +     }
> > +
> > +     for (i = 0; i < size; i++) {
> > +             ret = cdns_mhdp_mailbox_write(base, message[i]);
> > +             if (ret)
> > +                     return ret;
> > +     }
> > +
> > +     return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(cdns_mhdp_mailbox_send);
> > +
> > +/* General helper functions */
> > +int cdns_mhdp_reg_read(struct cdns_mhdp_base *base, u32 addr, u32
> > +*value) {
> > +     u8 msg[4], resp[8];
> > +     int ret;
> > +
> > +     put_unaligned_be32(addr, msg);
> > +
> > +     mutex_lock(base->mbox_mutex);
> > +
> > +     ret = cdns_mhdp_mailbox_send(base, MB_MODULE_ID_GENERAL,
> > +                                  GENERAL_REGISTER_READ,
> > +                                  sizeof(msg), msg);
> > +     if (ret)
> > +             goto out;
> > +
> > +     ret = cdns_mhdp_mailbox_recv_header(base,
> MB_MODULE_ID_GENERAL,
> > +
> GENERAL_REGISTER_READ,
> > +                                         sizeof(resp));
> > +     if (ret)
> > +             goto out;
> > +
> > +     ret = cdns_mhdp_mailbox_recv_data(base, resp, sizeof(resp));
> > +     if (ret)
> > +             goto out;
> > +
> > +     /* Returned address value should be the same as requested */
> > +     if (memcmp(msg, resp, sizeof(msg))) {
> > +             ret = -EINVAL;
> > +             goto out;
> > +     }
> > +
> > +     *value = get_unaligned_be32(resp + 4);
> > +
> > +out:
> > +     mutex_unlock(base->mbox_mutex);
> > +     if (ret) {
> > +             dev_err(base->dev, "Failed to read register\n");
> > +             *value = 0;
> > +     }
> > +
> > +     return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(cdns_mhdp_reg_read);
> > +
> > +int cdns_mhdp_reg_write(struct cdns_mhdp_base *base, u32 addr, u32
> > +val) {
> > +     u8 msg[8];
> > +     int ret;
> > +
> > +     put_unaligned_be32(addr, msg);
> > +     put_unaligned_be32(val, msg + 4);
> > +
> > +     mutex_lock(base->mbox_mutex);
> > +
> > +     ret = cdns_mhdp_mailbox_send(base, MB_MODULE_ID_GENERAL,
> > +                                  GENERAL_REGISTER_WRITE,
> > +                                  sizeof(msg), msg);
> > +
> > +     mutex_unlock(base->mbox_mutex);
> > +
> > +     return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(cdns_mhdp_reg_write);
> > +
> > +/* DPTX helper functions */
> > +int cdns_mhdp_dp_reg_write(struct cdns_mhdp_base *base, u16 addr,
> u32
> > +val) {
> > +     u8 msg[6];
> > +     int ret;
> > +
> > +     put_unaligned_be16(addr, msg);
> > +     put_unaligned_be32(val, msg + 2);
> > +
> > +     mutex_lock(base->mbox_mutex);
> > +
> > +     ret = cdns_mhdp_mailbox_send(base, MB_MODULE_ID_DP_TX,
> > +                                  DPTX_WRITE_REGISTER,
> sizeof(msg),
> msg);
> > +
> > +     mutex_unlock(base->mbox_mutex);
> > +
> > +     return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(cdns_mhdp_dp_reg_write);
> > +
> > +int cdns_mhdp_dp_reg_write_bit(struct cdns_mhdp_base *base, u16 addr,
> > +                            u8 start_bit, u8 bits_no, u32 val) {
> > +     u8 field[8];
> > +     int ret;
> > +
> > +     put_unaligned_be16(addr, field);
> > +     field[2] = start_bit;
> > +     field[3] = bits_no;
> > +     put_unaligned_be32(val, field + 4);
> > +
> > +     mutex_lock(base->mbox_mutex);
> > +
> > +     ret = cdns_mhdp_mailbox_send(base, MB_MODULE_ID_DP_TX,
> > +                                  DPTX_WRITE_FIELD,
> sizeof(field),
> field);
> > +
> > +     mutex_unlock(base->mbox_mutex);
> > +
> > +     return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(cdns_mhdp_dp_reg_write_bit);
> > +
> > +int cdns_mhdp_dpcd_read(struct cdns_mhdp_base *base,
> > +                     u32 addr, u8 *data, u16 len) {
> > +     u8 msg[5], reg[5];
> > +     int ret;
> > +
> > +     put_unaligned_be16(len, msg);
> > +     put_unaligned_be24(addr, msg + 2);
> > +
> > +     mutex_lock(base->mbox_mutex);
> > +
> > +     ret = cdns_mhdp_mailbox_send(base, MB_MODULE_ID_DP_TX,
> > +                                  DPTX_READ_DPCD, sizeof(msg),
> msg);
> > +     if (ret)
> > +             goto out;
> > +
> > +     ret = cdns_mhdp_mailbox_recv_header(base,
> MB_MODULE_ID_DP_TX,
> > +                                         DPTX_READ_DPCD,
> > +                                         sizeof(reg) + len);
> > +     if (ret)
> > +             goto out;
> > +
> > +     ret = cdns_mhdp_mailbox_recv_data(base, reg, sizeof(reg));
> > +     if (ret)
> > +             goto out;
> > +
> > +     ret = cdns_mhdp_mailbox_recv_data(base, data, len);
> > +
> > +out:
> > +     mutex_unlock(base->mbox_mutex);
> > +
> > +     return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(cdns_mhdp_dpcd_read);
> > +
> > +int cdns_mhdp_dpcd_write(struct cdns_mhdp_base *base, u32 addr, u8
> > +value) {
> > +     u8 msg[6], reg[5];
> > +     int ret;
> > +
> > +     put_unaligned_be16(1, msg);
> > +     put_unaligned_be24(addr, msg + 2);
> > +     msg[5] = value;
> > +
> > +     mutex_lock(base->mbox_mutex);
> > +
> > +     ret = cdns_mhdp_mailbox_send(base, MB_MODULE_ID_DP_TX,
> > +                                  DPTX_WRITE_DPCD,
> sizeof(msg),
> msg);
> > +     if (ret)
> > +             goto out;
> > +
> > +     ret = cdns_mhdp_mailbox_recv_header(base,
> MB_MODULE_ID_DP_TX,
> > +                                         DPTX_WRITE_DPCD,
> sizeof(reg));
> > +     if (ret)
> > +             goto out;
> > +
> > +     ret = cdns_mhdp_mailbox_recv_data(base, reg, sizeof(reg));
> > +     if (ret)
> > +             goto out;
> > +
> > +     if (addr != get_unaligned_be24(reg + 2))
> > +             ret = -EINVAL;
>
> No need to have the mutex locked while doing this check. This should be
> moved below 'out' label.

It is to check the recv data for cdns_mhdp_mailbox_recv_data() only,
if moved below "out" label, it will run for every maibox failed.
So it have to be keep in mutex lock.

>
> > +out:
> > +     mutex_unlock(base->mbox_mutex);
> > +
> > +     if (ret)
> > +             dev_err(base->dev, "dpcd write failed: %d\n", ret);
> > +     return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(cdns_mhdp_dpcd_write);
> > +
> > +MODULE_DESCRIPTION("Cadence MHDP Helper driver");
> > +MODULE_AUTHOR("Sandor Yu <Sandor.yu@nxp.com>");
> > +MODULE_LICENSE("GPL");
> > diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
> > b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c index
> > 6af565ac307ae..9d9dbb976868c 100644
> > --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
> > +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
> > @@ -73,298 +73,28 @@ static void cdns_mhdp_bridge_hpd_disable(struct
> > drm_bridge *bridge) mhdp->regs + CDNS_APB_INT_MASK);  }
> >
> > -static int cdns_mhdp_mailbox_read(struct cdns_mhdp_device *mhdp) -{
> > -     int ret, empty;
> > -
> > -     WARN_ON(!mutex_is_locked(&mhdp->mbox_mutex));
> > -
> > -     ret = readx_poll_timeout(readl, mhdp->regs +
> CDNS_MAILBOX_EMPTY,
> > -                              empty, !empty, MAILBOX_RETRY_US,
> > -                              MAILBOX_TIMEOUT_US);
> > -     if (ret < 0)
> > -             return ret;
> > -
> > -     return readl(mhdp->regs + CDNS_MAILBOX_RX_DATA) & 0xff;
> > -}
> > -
> > -static int cdns_mhdp_mailbox_write(struct cdns_mhdp_device *mhdp, u8
> > val) -{
> > -     int ret, full;
> > -
> > -     WARN_ON(!mutex_is_locked(&mhdp->mbox_mutex));
> > -
> > -     ret = readx_poll_timeout(readl, mhdp->regs +
> CDNS_MAILBOX_FULL,
> > -                              full, !full, MAILBOX_RETRY_US,
> > -                              MAILBOX_TIMEOUT_US);
> > -     if (ret < 0)
> > -             return ret;
> > -
> > -     writel(val, mhdp->regs + CDNS_MAILBOX_TX_DATA);
> > -
> > -     return 0;
> > -}
> > -
> > -static int cdns_mhdp_mailbox_recv_header(struct cdns_mhdp_device
> *mhdp,
> > -                                      u8 module_id, u8 opcode,
> > -                                      u16 req_size)
> > -{
> > -     u32 mbox_size, i;
> > -     u8 header[4];
> > -     int ret;
> > -
> > -     /* read the header of the message */
> > -     for (i = 0; i < sizeof(header); i++) {
> > -             ret = cdns_mhdp_mailbox_read(mhdp);
> > -             if (ret < 0)
> > -                     return ret;
> > -
> > -             header[i] = ret;
> > -     }
> > -
> > -     mbox_size = get_unaligned_be16(header + 2);
> > -
> > -     if (opcode != header[0] || module_id != header[1] ||
> > -         req_size != mbox_size) {
> > -             /*
> > -              * If the message in mailbox is not what we want, we need
> to
> > -              * clear the mailbox by reading its contents.
> > -              */
> > -             for (i = 0; i < mbox_size; i++)
> > -                     if (cdns_mhdp_mailbox_read(mhdp) < 0)
> > -                             break;
> > -
> > -             return -EINVAL;
> > -     }
> > -
> > -     return 0;
> > -}
> > -
> > -static int cdns_mhdp_mailbox_recv_data(struct cdns_mhdp_device
> *mhdp,
> > -                                    u8 *buff, u16 buff_size)
> > -{
> > -     u32 i;
> > -     int ret;
> > -
> > -     for (i = 0; i < buff_size; i++) {
> > -             ret = cdns_mhdp_mailbox_read(mhdp);
> > -             if (ret < 0)
> > -                     return ret;
> > -
> > -             buff[i] = ret;
> > -     }
> > -
> > -     return 0;
> > -}
> > -
> > -static int cdns_mhdp_mailbox_send(struct cdns_mhdp_device *mhdp, u8
> > module_id, -                            u8 opcode, u16 size, u8
> *message)
> > -{
> > -     u8 header[4];
> > -     int ret, i;
> > -
> > -     header[0] = opcode;
> > -     header[1] = module_id;
> > -     put_unaligned_be16(size, header + 2);
> > -
> > -     for (i = 0; i < sizeof(header); i++) {
> > -             ret = cdns_mhdp_mailbox_write(mhdp, header[i]);
> > -             if (ret)
> > -                     return ret;
> > -     }
> > -
> > -     for (i = 0; i < size; i++) {
> > -             ret = cdns_mhdp_mailbox_write(mhdp, message[i]);
> > -             if (ret)
> > -                     return ret;
> > -     }
> > -
> > -     return 0;
> > -}
> > -
> > -static
> > -int cdns_mhdp_reg_read(struct cdns_mhdp_device *mhdp, u32 addr, u32
> > *value) -{
> > -     u8 msg[4], resp[8];
> > -     int ret;
> > -
> > -     put_unaligned_be32(addr, msg);
> > -
> > -     mutex_lock(&mhdp->mbox_mutex);
> > -
> > -     ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_GENERAL,
> > -                                  GENERAL_REGISTER_READ,
> > -                                  sizeof(msg), msg);
> > -     if (ret)
> > -             goto out;
> > -
> > -     ret = cdns_mhdp_mailbox_recv_header(mhdp,
> MB_MODULE_ID_GENERAL,
> > -
> GENERAL_REGISTER_READ,
> > -                                         sizeof(resp));
> > -     if (ret)
> > -             goto out;
> > -
> > -     ret = cdns_mhdp_mailbox_recv_data(mhdp, resp, sizeof(resp));
> > -     if (ret)
> > -             goto out;
> > -
> > -     /* Returned address value should be the same as requested */
> > -     if (memcmp(msg, resp, sizeof(msg))) {
> > -             ret = -EINVAL;
> > -             goto out;
> > -     }
> > -
> > -     *value = get_unaligned_be32(resp + 4);
> > -
> > -out:
> > -     mutex_unlock(&mhdp->mbox_mutex);
> > -     if (ret) {
> > -             dev_err(mhdp->dev, "Failed to read register\n");
> > -             *value = 0;
> > -     }
> > -
> > -     return ret;
> > -}
> > -
> > -static
> > -int cdns_mhdp_reg_write(struct cdns_mhdp_device *mhdp, u16 addr, u32
> > val) -{
> > -     u8 msg[6];
> > -     int ret;
> > -
> > -     put_unaligned_be16(addr, msg);
> > -     put_unaligned_be32(val, msg + 2);
> > -
> > -     mutex_lock(&mhdp->mbox_mutex);
> > -
> > -     ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
> > -                                  DPTX_WRITE_REGISTER,
> sizeof(msg),
> msg);
> > -
> > -     mutex_unlock(&mhdp->mbox_mutex);
> > -
> > -     return ret;
> > -}
> > -
> >  static
> > -int cdns_mhdp_reg_write_bit(struct cdns_mhdp_device *mhdp, u16 addr,
> > -                         u8 start_bit, u8 bits_no, u32 val)
> > -{
> > -     u8 field[8];
> > -     int ret;
> > -
> > -     put_unaligned_be16(addr, field);
> > -     field[2] = start_bit;
> > -     field[3] = bits_no;
> > -     put_unaligned_be32(val, field + 4);
> > -
> > -     mutex_lock(&mhdp->mbox_mutex);
> > -
> > -     ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
> > -                                  DPTX_WRITE_FIELD,
> sizeof(field),
> field);
> > -
> > -     mutex_unlock(&mhdp->mbox_mutex);
> > -
> > -     return ret;
> > -}
> > -
> > -static
> > -int cdns_mhdp_dpcd_read(struct cdns_mhdp_device *mhdp,
> > -                     u32 addr, u8 *data, u16 len)
> > -{
> > -     u8 msg[5], reg[5];
> > -     int ret;
> > -
> > -     put_unaligned_be16(len, msg);
> > -     put_unaligned_be24(addr, msg + 2);
> > -
> > -     mutex_lock(&mhdp->mbox_mutex);
> > -
> > -     ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
> > -                                  DPTX_READ_DPCD, sizeof(msg),
> msg);
> > -     if (ret)
> > -             goto out;
> > -
> > -     ret = cdns_mhdp_mailbox_recv_header(mhdp,
> MB_MODULE_ID_DP_TX,
> > -                                         DPTX_READ_DPCD,
> > -                                         sizeof(reg) + len);
> > -     if (ret)
> > -             goto out;
> > -
> > -     ret = cdns_mhdp_mailbox_recv_data(mhdp, reg, sizeof(reg));
> > -     if (ret)
> > -             goto out;
> > -
> > -     ret = cdns_mhdp_mailbox_recv_data(mhdp, data, len);
> > -
> > -out:
> > -     mutex_unlock(&mhdp->mbox_mutex);
> > -
> > -     return ret;
> > -}
> > -
> > -static
> > -int cdns_mhdp_dpcd_write(struct cdns_mhdp_device *mhdp, u32 addr, u8
> > value)
> > +int cdns_mhdp_set_firmware_active(struct cdns_mhdp_device *mhdp,
> bool
> > enable) {
> > -     u8 msg[6], reg[5];
> > +     u8 status;
> >       int ret;
> >
> > -     put_unaligned_be16(1, msg);
> > -     put_unaligned_be24(addr, msg + 2);
> > -     msg[5] = value;
> > -
> >       mutex_lock(&mhdp->mbox_mutex);
> >
> > -     ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
> > -                                  DPTX_WRITE_DPCD,
> sizeof(msg),
> msg);
> > -     if (ret)
> > -             goto out;
> > -
> > -     ret = cdns_mhdp_mailbox_recv_header(mhdp,
> MB_MODULE_ID_DP_TX,
> > -                                         DPTX_WRITE_DPCD,
> sizeof(reg));
> > -     if (ret)
> > -             goto out;
> > +     status = enable ? FW_ACTIVE : FW_STANDBY;
>
> Initialising status can be done outside of the locked mutex.
OK.
>
> > -     ret = cdns_mhdp_mailbox_recv_data(mhdp, reg, sizeof(reg));
> > +     ret = cdns_mhdp_mailbox_send(&mhdp->base,
> MB_MODULE_ID_GENERAL,
> > +                                  GENERAL_MAIN_CONTROL,
> sizeof(status), &status);
> >       if (ret)
> >               goto out;
> >
> > -     if (addr != get_unaligned_be24(reg + 2))
> > -             ret = -EINVAL;
> > -
> > -out:
> > -     mutex_unlock(&mhdp->mbox_mutex);
> > -
> > -     if (ret)
> > -             dev_err(mhdp->dev, "dpcd write failed: %d\n", ret);
> > -     return ret;
> > -}
> > -
> > -static
> > -int cdns_mhdp_set_firmware_active(struct cdns_mhdp_device *mhdp,
> bool
> > enable) -{
> > -     u8 msg[5];
> > -     int ret, i;
> > -
> > -     msg[0] = GENERAL_MAIN_CONTROL;
> > -     msg[1] = MB_MODULE_ID_GENERAL;
> > -     msg[2] = 0;
> > -     msg[3] = 1;
> > -     msg[4] = enable ? FW_ACTIVE : FW_STANDBY;
> > -
> > -     mutex_lock(&mhdp->mbox_mutex);
> > -
> > -     for (i = 0; i < sizeof(msg); i++) {
> > -             ret = cdns_mhdp_mailbox_write(mhdp, msg[i]);
> > -             if (ret)
> > -                     goto out;
> > -     }
> > -
> > -     /* read the firmware state */
> > -     ret = cdns_mhdp_mailbox_recv_data(mhdp, msg, sizeof(msg));
> > +     ret = cdns_mhdp_mailbox_recv_header(&mhdp->base,
> MB_MODULE_ID_GENERAL,
> > +
> GENERAL_MAIN_CONTROL,
> > +                                         sizeof(status));
> >       if (ret)
> >               goto out;
> >
> > -     ret = 0;
> > +     ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, &status,
> sizeof(status));
> >
> >  out:
> >       mutex_unlock(&mhdp->mbox_mutex); @@ -382,18 +112,18 @@
> int
> > cdns_mhdp_get_hpd_status(struct cdns_mhdp_device
> > *mhdp)
> >
> >       mutex_lock(&mhdp->mbox_mutex);
> >
> > -     ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
> > +     ret = cdns_mhdp_mailbox_send(&mhdp->base,
> MB_MODULE_ID_DP_TX,
> >                                    DPTX_HPD_STATE, 0, NULL);
> >       if (ret)
> >               goto err_get_hpd;
> >
> > -     ret = cdns_mhdp_mailbox_recv_header(mhdp,
> MB_MODULE_ID_DP_TX,
> > +     ret = cdns_mhdp_mailbox_recv_header(&mhdp->base,
> > + MB_MODULE_ID_DP_TX,
> >                                           DPTX_HPD_STATE,
> >                                           sizeof(status));
> >       if (ret)
> >               goto err_get_hpd;
> >
> > -     ret = cdns_mhdp_mailbox_recv_data(mhdp, &status, sizeof(status));
> > +     ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, &status,
> sizeof(status));
> >       if (ret)
> >               goto err_get_hpd;
> >
> > @@ -424,22 +154,22 @@ int cdns_mhdp_get_edid_block(void *data, u8
> *edid,
> >               msg[0] = block / 2;
> >               msg[1] = block % 2;
> >
> > -             ret = cdns_mhdp_mailbox_send(mhdp,
> MB_MODULE_ID_DP_TX,
> > +             ret = cdns_mhdp_mailbox_send(&mhdp->base,
> MB_MODULE_ID_DP_TX,
> >                                            DPTX_GET_EDID,
> sizeof(msg), msg);
> >               if (ret)
> >                       continue;
> >
> > -             ret = cdns_mhdp_mailbox_recv_header(mhdp,
> MB_MODULE_ID_DP_TX,
> > +             ret = cdns_mhdp_mailbox_recv_header(&mhdp->base,
> MB_MODULE_ID_DP_TX,
> >
> DPTX_GET_EDID,
> >                                                   sizeof(reg) +
> length);
> >               if (ret)
> >                       continue;
> >
> > -             ret = cdns_mhdp_mailbox_recv_data(mhdp, reg,
> sizeof(reg));
> > +             ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, reg,
> sizeof(reg));
> >               if (ret)
> >                       continue;
> >
> > -             ret = cdns_mhdp_mailbox_recv_data(mhdp, edid, length);
> > +             ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, edid,
> length);
> >               if (ret)
> >                       continue;
> >
> > @@ -464,17 +194,17 @@ int cdns_mhdp_read_hpd_event(struct
> > cdns_mhdp_device
> > *mhdp)
> >
> >       mutex_lock(&mhdp->mbox_mutex);
> >
> > -     ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
> > +     ret = cdns_mhdp_mailbox_send(&mhdp->base,
> MB_MODULE_ID_DP_TX,
> >                                    DPTX_READ_EVENT, 0, NULL);
> >       if (ret)
> >               goto out;
> >
> > -     ret = cdns_mhdp_mailbox_recv_header(mhdp,
> MB_MODULE_ID_DP_TX,
> > +     ret = cdns_mhdp_mailbox_recv_header(&mhdp->base,
> > + MB_MODULE_ID_DP_TX,
> >                                           DPTX_READ_EVENT,
> sizeof(event));
> >       if (ret < 0)
> >               goto out;
> >
> > -     ret = cdns_mhdp_mailbox_recv_data(mhdp, &event, sizeof(event));
> > +     ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, &event,
> sizeof(event));
> >  out:
> >       mutex_unlock(&mhdp->mbox_mutex);
> >
> > @@ -512,20 +242,20 @@ int cdns_mhdp_adjust_lt(struct
> cdns_mhdp_device
> > *mhdp, unsigned int nlanes,
> >
> >       mutex_lock(&mhdp->mbox_mutex);
> >
> > -     ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
> > +     ret = cdns_mhdp_mailbox_send(&mhdp->base,
> MB_MODULE_ID_DP_TX,
> >                                    DPTX_ADJUST_LT,
> >                                    sizeof(payload), payload);
> >       if (ret)
> >               goto out;
> >
> >       /* Yes, read the DPCD read command response */
> > -     ret = cdns_mhdp_mailbox_recv_header(mhdp,
> MB_MODULE_ID_DP_TX,
> > +     ret = cdns_mhdp_mailbox_recv_header(&mhdp->base,
> > + MB_MODULE_ID_DP_TX,
> >                                           DPTX_READ_DPCD,
> >                                           sizeof(hdr) +
> DP_LINK_STATUS_SIZE);
> >       if (ret)
> >               goto out;
> >
> > -     ret = cdns_mhdp_mailbox_recv_data(mhdp, hdr, sizeof(hdr));
> > +     ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, hdr,
> > + sizeof(hdr));
> >       if (ret)
> >               goto out;
> >
> > @@ -533,7 +263,7 @@ int cdns_mhdp_adjust_lt(struct cdns_mhdp_device
> > *mhdp, unsigned int nlanes, if (addr != DP_LANE0_1_STATUS)
> >               goto out;
> >
> > -     ret = cdns_mhdp_mailbox_recv_data(mhdp, link_status,
> > +     ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, link_status,
> >                                         DP_LINK_STATUS_SIZE);
> >
> >  out:
> > @@ -847,7 +577,7 @@ static ssize_t cdns_mhdp_transfer(struct
> > drm_dp_aux *aux, unsigned int i;
> >
> >               for (i = 0; i < msg->size; ++i) {
> > -                     ret = cdns_mhdp_dpcd_write(mhdp,
> > +                     ret = cdns_mhdp_dpcd_write(&mhdp->base,
> >                                                  msg->address
> +
> i, buf[i]);
> >                       if (!ret)
> >                               continue; @@ -859,7 +589,7 @@
> static
> > ssize_t cdns_mhdp_transfer(struct drm_dp_aux *aux, return ret;
> >               }
> >       } else {
> > -             ret = cdns_mhdp_dpcd_read(mhdp, msg->address,
> > +             ret = cdns_mhdp_dpcd_read(&mhdp->base,
> msg->address,
> >                                         msg->buffer, msg->size);
> >               if (ret) {
> >                       dev_err(mhdp->dev, @@ -887,12 +617,12 @@
> static
> > int cdns_mhdp_link_training_init(struct
> > cdns_mhdp_device *mhdp) if (!mhdp->host.scrambler)
> >               reg32 |= CDNS_PHY_SCRAMBLER_BYPASS;
> >
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DPTX_PHY_CONFIG, reg32);
> > +     cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_PHY_CONFIG,
> reg32);
> >
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DP_ENHNCD,
> > +     cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_ENHNCD,
> >                           mhdp->sink.enhanced &
> mhdp->host.enhanced);
> >
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DP_LANE_EN,
> > +     cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_LANE_EN,
> >                           CDNS_DP_LANE_EN_LANES(mhdp-
> >link.num_lanes));
> >
> >       cdns_mhdp_link_configure(&mhdp->aux, &mhdp->link); @@ -913,7
> > +643,7 @@ static int cdns_mhdp_link_training_init(struct
> > cdns_mhdp_device *mhdp) return ret;
> >       }
> >
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DPTX_PHY_CONFIG,
> > +     cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_PHY_CONFIG,
> >                           CDNS_PHY_COMMON_CONFIG |
> >                           CDNS_PHY_TRAINING_EN |
> >                           CDNS_PHY_TRAINING_TYPE(1) | @@
> -1058,7
> > +788,7 @@ static bool cdns_mhdp_link_training_channel_eq(struct
> > cdns_mhdp_device *mhdp, CDNS_PHY_TRAINING_TYPE(eq_tps);
> >       if (eq_tps != 4)
> >               reg32 |= CDNS_PHY_SCRAMBLER_BYPASS;
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DPTX_PHY_CONFIG, reg32);
> > +     cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_PHY_CONFIG,
> reg32);
> >
> >       drm_dp_dpcd_writeb(&mhdp->aux, DP_TRAINING_PATTERN_SET,
> >                          (eq_tps != 4) ? eq_tps |
> DP_LINK_SCRAMBLING_DISABLE :
> > @@ -1322,7 +1052,7 @@ static int cdns_mhdp_link_training(struct
> > cdns_mhdp_device *mhdp, mhdp->host.scrambler ? 0 :
> >                          DP_LINK_SCRAMBLING_DISABLE);
> >
> > -     ret = cdns_mhdp_reg_read(mhdp,
> CDNS_DP_FRAMER_GLOBAL_CONFIG,
> &reg32);
> > +     ret = cdns_mhdp_reg_read(&mhdp->base,
> > + CDNS_DP_FRAMER_GLOBAL_CONFIG,
> > &reg32); if (ret < 0) {
> >               dev_err(mhdp->dev,
> >                       "Failed to read
> CDNS_DP_FRAMER_GLOBAL_CONFIG
> %d\n",
> > @@ -1333,13 +1063,13 @@ static int cdns_mhdp_link_training(struct
> > cdns_mhdp_device *mhdp, reg32 |=
> CDNS_DP_NUM_LANES(mhdp->link.num_lanes);
> >       reg32 |= CDNS_DP_WR_FAILING_EDGE_VSYNC;
> >       reg32 |= CDNS_DP_FRAMER_EN;
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG,
> reg32);
> > +     cdns_mhdp_reg_write(&mhdp->base,
> CDNS_DP_FRAMER_GLOBAL_CONFIG,
> reg32);
> >
> >       /* Reset PHY config */
> >       reg32 = CDNS_PHY_COMMON_CONFIG |
> CDNS_PHY_TRAINING_TYPE(1);
> >       if (!mhdp->host.scrambler)
> >               reg32 |= CDNS_PHY_SCRAMBLER_BYPASS;
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DPTX_PHY_CONFIG, reg32);
> > +     cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_PHY_CONFIG,
> reg32);
> >
> >       return 0;
> >  err:
> > @@ -1347,7 +1077,7 @@ static int cdns_mhdp_link_training(struct
> > cdns_mhdp_device *mhdp, reg32 = CDNS_PHY_COMMON_CONFIG |
> > CDNS_PHY_TRAINING_TYPE(1);
> >       if (!mhdp->host.scrambler)
> >               reg32 |= CDNS_PHY_SCRAMBLER_BYPASS;
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DPTX_PHY_CONFIG, reg32);
> > +     cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_PHY_CONFIG,
> reg32);
> >
> >       drm_dp_dpcd_writeb(&mhdp->aux, DP_TRAINING_PATTERN_SET,
> >                          DP_TRAINING_PATTERN_DISABLE); @@
> -1461,7
> > +1191,7 @@ static int cdns_mhdp_link_up(struct cdns_mhdp_device
> > *mhdp) mhdp->link.num_lanes = cdns_mhdp_max_num_lanes(mhdp);
> >
> >       /* Disable framer for link training */
> > -     err = cdns_mhdp_reg_read(mhdp,
> CDNS_DP_FRAMER_GLOBAL_CONFIG, &resp);
> > +     err = cdns_mhdp_reg_read(&mhdp->base,
> > + CDNS_DP_FRAMER_GLOBAL_CONFIG,
> > &resp); if (err < 0) {
> >               dev_err(mhdp->dev,
> >                       "Failed to read
> CDNS_DP_FRAMER_GLOBAL_CONFIG
> %d\n",
> > @@ -1470,7 +1200,7 @@ static int cdns_mhdp_link_up(struct
> > cdns_mhdp_device
> > *mhdp) }
> >
> >       resp &= ~CDNS_DP_FRAMER_EN;
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG,
> resp);
> > +     cdns_mhdp_reg_write(&mhdp->base,
> CDNS_DP_FRAMER_GLOBAL_CONFIG,
> resp);
> >
> >       /* Spread AMP if required, enable 8b/10b coding */
> >       amp[0] = cdns_mhdp_get_ssc_supported(mhdp) ?
> DP_SPREAD_AMP_0_5 :
> > 0; @@ -1837,7 +1567,7 @@ static void cdns_mhdp_configure_video(struct
> > cdns_mhdp_device *mhdp, if (mode->flags &
> DRM_MODE_FLAG_INTERLACE)
> >               bnd_hsync2vsync |=
> CDNS_IP_DET_INTERLACE_FORMAT;
> >
> > -     cdns_mhdp_reg_write(mhdp,
> CDNS_BND_HSYNC2VSYNC(stream_id),
> > +     cdns_mhdp_reg_write(&mhdp->base,
> > + CDNS_BND_HSYNC2VSYNC(stream_id),
> >                           bnd_hsync2vsync);
> >
> >       hsync2vsync_pol_ctrl = 0;
> > @@ -1845,10 +1575,10 @@ static void cdns_mhdp_configure_video(struct
> > cdns_mhdp_device *mhdp, hsync2vsync_pol_ctrl |=
> > CDNS_H2V_HSYNC_POL_ACTIVE_LOW;
> >       if (mode->flags & DRM_MODE_FLAG_NVSYNC)
> >               hsync2vsync_pol_ctrl |=
> CDNS_H2V_VSYNC_POL_ACTIVE_LOW;
> > -     cdns_mhdp_reg_write(mhdp,
> CDNS_HSYNC2VSYNC_POL_CTRL(stream_id),
> > +     cdns_mhdp_reg_write(&mhdp->base,
> CDNS_HSYNC2VSYNC_POL_CTRL(stream_id),
> >                           hsync2vsync_pol_ctrl);
> >
> > -     cdns_mhdp_reg_write(mhdp,
> CDNS_DP_FRAMER_PXL_REPR(stream_id),
> pxl_repr);
> > +     cdns_mhdp_reg_write(&mhdp->base,
> > + CDNS_DP_FRAMER_PXL_REPR(stream_id),
> > pxl_repr);
> >
> >       if (mode->flags & DRM_MODE_FLAG_INTERLACE)
> >               dp_framer_sp |= CDNS_DP_FRAMER_INTERLACE; @@
> -1856,19
> > +1586,19 @@ static void cdns_mhdp_configure_video(struct
> > cdns_mhdp_device *mhdp, dp_framer_sp |=
> CDNS_DP_FRAMER_HSYNC_POL_LOW;
> >       if (mode->flags & DRM_MODE_FLAG_NVSYNC)
> >               dp_framer_sp |= CDNS_DP_FRAMER_VSYNC_POL_LOW;
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_SP(stream_id),
> dp_framer_sp);
> > +     cdns_mhdp_reg_write(&mhdp->base,
> CDNS_DP_FRAMER_SP(stream_id),
> > dp_framer_sp);
> >
> >       front_porch = mode->crtc_hsync_start - mode->crtc_hdisplay;
> >       back_porch = mode->crtc_htotal - mode->crtc_hsync_end;
> > -     cdns_mhdp_reg_write(mhdp,
> CDNS_DP_FRONT_BACK_PORCH(stream_id),
> > +     cdns_mhdp_reg_write(&mhdp->base,
> CDNS_DP_FRONT_BACK_PORCH(stream_id),
> >                           CDNS_DP_FRONT_PORCH(front_porch) |
> >                           CDNS_DP_BACK_PORCH(back_porch));
> >
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DP_BYTE_COUNT(stream_id),
> > +     cdns_mhdp_reg_write(&mhdp->base,
> CDNS_DP_BYTE_COUNT(stream_id),
> >                           mode->crtc_hdisplay * bpp / 8);
> >
> >       msa_h0 = mode->crtc_htotal - mode->crtc_hsync_start;
> > -     cdns_mhdp_reg_write(mhdp,
> CDNS_DP_MSA_HORIZONTAL_0(stream_id),
> > +     cdns_mhdp_reg_write(&mhdp->base,
> CDNS_DP_MSA_HORIZONTAL_0(stream_id),
> >
> CDNS_DP_MSAH0_H_TOTAL(mode->crtc_htotal) |
> >
> CDNS_DP_MSAH0_HSYNC_START(msa_h0));
> >
> > @@ -1877,11 +1607,11 @@ static void cdns_mhdp_configure_video(struct
> > cdns_mhdp_device *mhdp,
> CDNS_DP_MSAH1_HDISP_WIDTH(mode->crtc_hdisplay);
> >       if (mode->flags & DRM_MODE_FLAG_NHSYNC)
> >               msa_horizontal_1 |=
> CDNS_DP_MSAH1_HSYNC_POL_LOW;
> > -     cdns_mhdp_reg_write(mhdp,
> CDNS_DP_MSA_HORIZONTAL_1(stream_id),
> > +     cdns_mhdp_reg_write(&mhdp->base,
> CDNS_DP_MSA_HORIZONTAL_1(stream_id),
> >                           msa_horizontal_1);
> >
> >       msa_v0 = mode->crtc_vtotal - mode->crtc_vsync_start;
> > -     cdns_mhdp_reg_write(mhdp,
> CDNS_DP_MSA_VERTICAL_0(stream_id),
> > +     cdns_mhdp_reg_write(&mhdp->base,
> > + CDNS_DP_MSA_VERTICAL_0(stream_id),
> >
> CDNS_DP_MSAV0_V_TOTAL(mode->crtc_vtotal) |
> >
> CDNS_DP_MSAV0_VSYNC_START(msa_v0));
> >
> > @@ -1890,7 +1620,7 @@ static void cdns_mhdp_configure_video(struct
> > cdns_mhdp_device *mhdp,
> CDNS_DP_MSAV1_VDISP_WIDTH(mode->crtc_vdisplay);
> >       if (mode->flags & DRM_MODE_FLAG_NVSYNC)
> >               msa_vertical_1 |= CDNS_DP_MSAV1_VSYNC_POL_LOW;
> > -     cdns_mhdp_reg_write(mhdp,
> CDNS_DP_MSA_VERTICAL_1(stream_id),
> > +     cdns_mhdp_reg_write(&mhdp->base,
> > + CDNS_DP_MSA_VERTICAL_1(stream_id),
> >                           msa_vertical_1);
> >
> >       if ((mode->flags & DRM_MODE_FLAG_INTERLACE) && @@
> -1902,14
> > +1632,14 @@ static void cdns_mhdp_configure_video(struct
> > cdns_mhdp_device *mhdp, if (pxlfmt == DRM_COLOR_FORMAT_YCBCR420)
> >               misc1 = CDNS_DP_TEST_VSC_SDP;
> >
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_MISC(stream_id),
> > +     cdns_mhdp_reg_write(&mhdp->base,
> CDNS_DP_MSA_MISC(stream_id),
> >                           misc0 | (misc1 << 8));
> >
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DP_HORIZONTAL(stream_id),
> > +     cdns_mhdp_reg_write(&mhdp->base,
> CDNS_DP_HORIZONTAL(stream_id),
> >                           CDNS_DP_H_HSYNC_WIDTH(hsync) |
> >
> CDNS_DP_H_H_TOTAL(mode->crtc_hdisplay));
> >
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DP_VERTICAL_0(stream_id),
> > +     cdns_mhdp_reg_write(&mhdp->base,
> CDNS_DP_VERTICAL_0(stream_id),
> >
> CDNS_DP_V0_VHEIGHT(mode->crtc_vdisplay) |
> >                           CDNS_DP_V0_VSTART(msa_v0));
> >
> > @@ -1918,13 +1648,13 @@ static void cdns_mhdp_configure_video(struct
> > cdns_mhdp_device *mhdp, mode->crtc_vtotal % 2 == 0)
> >               dp_vertical_1 |= CDNS_DP_V1_VTOTAL_EVEN;
> >
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DP_VERTICAL_1(stream_id),
> dp_vertical_1);
> > +     cdns_mhdp_reg_write(&mhdp->base,
> CDNS_DP_VERTICAL_1(stream_id),
> > dp_vertical_1);
> >
> > -     cdns_mhdp_reg_write_bit(mhdp, CDNS_DP_VB_ID(stream_id), 2, 1,
> > -                             (mode->flags &
> DRM_MODE_FLAG_INTERLACE) ?
> > -                             CDNS_DP_VB_ID_INTERLACED : 0);
> > +     cdns_mhdp_dp_reg_write_bit(&mhdp->base,
> > + CDNS_DP_VB_ID(stream_id), 2,
> 1,
> > +                                (mode->flags &
> DRM_MODE_FLAG_INTERLACE) ?
> > +                                CDNS_DP_VB_ID_INTERLACED :
> 0);
> >
> > -     ret = cdns_mhdp_reg_read(mhdp,
> CDNS_DP_FRAMER_GLOBAL_CONFIG,
> &framer);
> > +     ret = cdns_mhdp_reg_read(&mhdp->base,
> > + CDNS_DP_FRAMER_GLOBAL_CONFIG,
> > &framer); if (ret < 0) {
> >               dev_err(mhdp->dev,
> >                       "Failed to read
> CDNS_DP_FRAMER_GLOBAL_CONFIG
> %d\n",
> > @@ -1933,7 +1663,7 @@ static void cdns_mhdp_configure_video(struct
> > cdns_mhdp_device *mhdp, }
> >       framer |= CDNS_DP_FRAMER_EN;
> >       framer &= ~CDNS_DP_NO_VIDEO_MODE;
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG,
> framer);
> > +     cdns_mhdp_reg_write(&mhdp->base,
> CDNS_DP_FRAMER_GLOBAL_CONFIG,
> framer);
> >  }
> >
> >  static void cdns_mhdp_sst_enable(struct cdns_mhdp_device *mhdp, @@
> > -1966,15 +1696,15 @@ static void cdns_mhdp_sst_enable(struct
> > cdns_mhdp_device *mhdp,
> >
> >       mhdp->stream_id = 0;
> >
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_TU,
> > +     cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_FRAMER_TU,
> >                           CDNS_DP_FRAMER_TU_VS(vs) |
> >                           CDNS_DP_FRAMER_TU_SIZE(tu_size) |
> >                           CDNS_DP_FRAMER_TU_CNT_RST_EN);
> >
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DP_LINE_THRESH(0),
> > +     cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_LINE_THRESH(0),
> >                           line_thresh & GENMASK(5, 0));
> >
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DP_STREAM_CONFIG_2(0),
> > +     cdns_mhdp_reg_write(&mhdp->base,
> CDNS_DP_STREAM_CONFIG_2(0),
> >                           CDNS_DP_SC2_TU_VS_DIFF((tu_size - vs >
> 3) ?
> >                                                  0 : tu_size -
> vs));
> >
> > @@ -2009,13 +1739,13 @@ static void cdns_mhdp_atomic_enable(struct
> > drm_bridge *bridge, mhdp->info->ops->enable(mhdp);
> >
> >       /* Enable VIF clock for stream 0 */
> > -     ret = cdns_mhdp_reg_read(mhdp, CDNS_DPTX_CAR, &resp);
> > +     ret = cdns_mhdp_reg_read(&mhdp->base, CDNS_DPTX_CAR,
> &resp);
> >       if (ret < 0) {
> >               dev_err(mhdp->dev, "Failed to read
> CDNS_DPTX_CAR %d\n",
> ret);
> >               goto out;
> >       }
> >
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DPTX_CAR,
> > +     cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_CAR,
> >                           resp | CDNS_VIF_CLK_EN |
> CDNS_VIF_CLK_RSTN);
> >
> >       connector = drm_atomic_get_new_connector_for_encoder(state,
> > @@ -2083,16 +1813,16 @@ static void cdns_mhdp_atomic_disable(struct
> > drm_bridge *bridge, cdns_mhdp_hdcp_disable(mhdp);
> >
> >       mhdp->bridge_enabled = false;
> > -     cdns_mhdp_reg_read(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG,
> &resp);
> > +     cdns_mhdp_reg_read(&mhdp->base,
> CDNS_DP_FRAMER_GLOBAL_CONFIG,
> &resp);
> >       resp &= ~CDNS_DP_FRAMER_EN;
> >       resp |= CDNS_DP_NO_VIDEO_MODE;
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG,
> resp);
> > +     cdns_mhdp_reg_write(&mhdp->base,
> CDNS_DP_FRAMER_GLOBAL_CONFIG,
> resp);
> >
> >       cdns_mhdp_link_down(mhdp);
> >
> >       /* Disable VIF clock for stream 0 */
> > -     cdns_mhdp_reg_read(mhdp, CDNS_DPTX_CAR, &resp);
> > -     cdns_mhdp_reg_write(mhdp, CDNS_DPTX_CAR,
> > +     cdns_mhdp_reg_read(&mhdp->base, CDNS_DPTX_CAR, &resp);
> > +     cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_CAR,
> >                           resp & ~(CDNS_VIF_CLK_EN |
> CDNS_VIF_CLK_RSTN));
> >
> >       if (mhdp->info && mhdp->info->ops && mhdp->info->ops->disable)
> > @@ -2502,6 +2232,11 @@ static int cdns_mhdp_probe(struct
> > platform_device
> > *pdev)
> >
> >       platform_set_drvdata(pdev, mhdp);
> >
> > +     /* init base struct for access mailbox  */
> > +     mhdp->base.dev = mhdp->dev;
> > +     mhdp->base.regs = mhdp->regs;
> > +     mhdp->base.mbox_mutex = &mhdp->mbox_mutex;
> > +
> >       mhdp->info = of_device_get_match_data(dev);
> >
> >       clk_prepare_enable(clk);
> > diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h
> > b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h index
> > bad2fc0c73066..f08db38c82bbd 100644
> > --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h
> > +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h
> > @@ -15,6 +15,7 @@
> >  #include <linux/mutex.h>
> >  #include <linux/spinlock.h>
> >
> > +#include <drm/bridge/cdns-mhdp-helper.h>
> >  #include <drm/display/drm_dp_helper.h>  #include <drm/drm_bridge.h>
> > #include <drm/drm_connector.h> @@ -27,10 +28,6 @@ struct phy;
> >  #define CDNS_APB_CTRL                                0x00000
> >  #define CDNS_CPU_STALL                               BIT(3)
> >
> > -#define CDNS_MAILBOX_FULL                    0x00008
> > -#define CDNS_MAILBOX_EMPTY                   0x0000c
> > -#define CDNS_MAILBOX_TX_DATA                 0x00010
> > -#define CDNS_MAILBOX_RX_DATA                 0x00014
> >  #define CDNS_KEEP_ALIVE                              0x00018
> >  #define CDNS_KEEP_ALIVE_MASK                 GENMASK(7, 0)
> >
> > @@ -198,45 +195,10 @@ struct phy;
> >  #define CDNS_DP_BYTE_COUNT(s)
> (CDNS_DPTX_STREAM(s) + 0x7c)
> >  #define CDNS_DP_BYTE_COUNT_BYTES_IN_CHUNK_SHIFT      16
> >
> > -/* mailbox */
> > -#define MAILBOX_RETRY_US                     1000
> > -#define MAILBOX_TIMEOUT_US                   2000000
> > -
> > -#define MB_OPCODE_ID                         0
> > -#define MB_MODULE_ID                         1
> > -#define MB_SIZE_MSB_ID                               2
> > -#define MB_SIZE_LSB_ID                               3
> > -#define MB_DATA_ID                           4
> > -
> > -#define MB_MODULE_ID_DP_TX                   0x01
> > -#define MB_MODULE_ID_HDCP_TX                 0x07
> > -#define MB_MODULE_ID_HDCP_RX                 0x08
> > -#define MB_MODULE_ID_HDCP_GENERAL            0x09
> > -#define MB_MODULE_ID_GENERAL                 0x0a
> > -
> > -/* firmware and opcodes */
> > +/* firmware */
> >  #define FW_NAME
> "cadence/
> mhdp8546.bin"
> >  #define CDNS_MHDP_IMEM
> 0x10000
> >
> > -#define GENERAL_MAIN_CONTROL                 0x01
> > -#define GENERAL_TEST_ECHO                    0x02
> > -#define GENERAL_BUS_SETTINGS                 0x03
> > -#define GENERAL_TEST_ACCESS                  0x04
> > -#define GENERAL_REGISTER_READ                        0x07
> > -
> > -#define DPTX_SET_POWER_MNG                   0x00
> > -#define DPTX_GET_EDID                                0x02
> > -#define DPTX_READ_DPCD                               0x03
> > -#define DPTX_WRITE_DPCD                              0x04
> > -#define DPTX_ENABLE_EVENT                    0x05
> > -#define DPTX_WRITE_REGISTER                  0x06
> > -#define DPTX_READ_REGISTER                   0x07
> > -#define DPTX_WRITE_FIELD                     0x08
> > -#define DPTX_READ_EVENT                              0x0a
> > -#define DPTX_GET_LAST_AUX_STAUS                      0x0e
> > -#define DPTX_HPD_STATE                               0x11
> > -#define DPTX_ADJUST_LT                               0x12
> > -
> >  #define FW_STANDBY                           0
> >  #define FW_ACTIVE                            1
> >
> > @@ -352,6 +314,8 @@ struct cdns_mhdp_hdcp {  };
> >
> >  struct cdns_mhdp_device {
> > +     struct cdns_mhdp_base base;
> > +
> >       void __iomem *regs;
> >       void __iomem *sapb_regs;
> >       void __iomem *j721e_regs;
> > diff --git a/include/drm/bridge/cdns-mhdp-helper.h
> > b/include/drm/bridge/cdns-mhdp-helper.h new file mode 100644 index
> > 0000000000000..477e67601ee5f
> > --- /dev/null
> > +++ b/include/drm/bridge/cdns-mhdp-helper.h
> > @@ -0,0 +1,94 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Copyright (C) 2023 NXP Semiconductor, Inc.
> > + */
> > +#ifndef __CDNS_MHDP_HELPER_H__
> > +#define __CDNS_MHDP_HELPER_H__
> > +
> > +#include <asm/unaligned.h>
> > +#include <linux/iopoll.h>
> > +
> > +/* mailbox regs offset */
> > +#define CDNS_MAILBOX_FULL                    0x00008
> > +#define CDNS_MAILBOX_EMPTY                   0x0000c
> > +#define CDNS_MAILBOX_TX_DATA                 0x00010
> > +#define CDNS_MAILBOX_RX_DATA                 0x00014
> > +
> > +#define MAILBOX_RETRY_US                     1000
> > +#define MAILBOX_TIMEOUT_US                   2000000
> > +
> > +/* Module ID Code */
> > +#define MB_MODULE_ID_DP_TX                   0x01
> > +#define MB_MODULE_ID_HDMI_TX                 0x03
> > +#define MB_MODULE_ID_HDCP_TX                 0x07
> > +#define MB_MODULE_ID_HDCP_RX                 0x08
> > +#define MB_MODULE_ID_HDCP_GENERAL            0x09
> > +#define MB_MODULE_ID_GENERAL                 0x0A
> > +
> > +/* General Commands */
> > +#define GENERAL_MAIN_CONTROL                 0x01
> > +#define GENERAL_TEST_ECHO                    0x02
> > +#define GENERAL_BUS_SETTINGS                 0x03
> > +#define GENERAL_TEST_ACCESS                  0x04
> > +#define GENERAL_REGISTER_WRITE                       0x05
> > +#define GENERAL_WRITE_FIELD                  0x06
> > +#define GENERAL_REGISTER_READ                        0x07
> > +#define GENERAL_GET_HPD_STATE                        0x11
> > +
> > +/* DPTX Commands */
> > +#define DPTX_SET_POWER_MNG                   0x00
> > +#define DPTX_SET_HOST_CAPABILITIES           0x01
> > +#define DPTX_GET_EDID                                0x02
> > +#define DPTX_READ_DPCD                               0x03
> > +#define DPTX_WRITE_DPCD                              0x04
> > +#define DPTX_ENABLE_EVENT                    0x05
> > +#define DPTX_WRITE_REGISTER                  0x06
> > +#define DPTX_READ_REGISTER                   0x07
> > +#define DPTX_WRITE_FIELD                     0x08
> > +#define DPTX_TRAINING_CONTROL                        0x09
> > +#define DPTX_READ_EVENT                              0x0a
> > +#define DPTX_READ_LINK_STAT                  0x0b
> > +#define DPTX_SET_VIDEO                               0x0c
> > +#define DPTX_SET_AUDIO                               0x0d
> > +#define DPTX_GET_LAST_AUX_STAUS                      0x0e
> > +#define DPTX_SET_LINK_BREAK_POINT            0x0f
> > +#define DPTX_FORCE_LANES                     0x10
> > +#define DPTX_HPD_STATE                               0x11
> > +#define DPTX_ADJUST_LT                               0x12
> > +
> > +/* HDMI TX Commands */
> > +#define HDMI_TX_READ                         0x00
> > +#define HDMI_TX_WRITE                                0x01
> > +#define HDMI_TX_UPDATE_READ                  0x02
> > +#define HDMI_TX_EDID                         0x03
> > +#define HDMI_TX_EVENTS                               0x04
> > +#define HDMI_TX_HPD_STATUS                   0x05
> > +
> > +struct cdns_mhdp_base {
> > +     struct device *dev;
> > +     void __iomem *regs;
> > +     /* protect mailbox communications with the firmware */
> > +     struct mutex *mbox_mutex;
> > +};
> > +
> > +/* Mailbox helper functions */
> > +int cdns_mhdp_mailbox_send(struct cdns_mhdp_base *base, u8
> module_id,
> > +                        u8 opcode, u16 size, u8 *message);
>
> Any reason to move the declaration for send before recv? It seems reasonable
> to have the in alphabetical order.

OK.

>
> > +int cdns_mhdp_mailbox_recv_header(struct cdns_mhdp_base *base,
> > +                               u8 module_id, u8 opcode, u16
> req_size);
> > +int cdns_mhdp_mailbox_recv_data(struct cdns_mhdp_base *base,
> > +                             u8 *buff, u16 buff_size);
>
> AFAICS while calling a sequence of these 3 functions mhdp->mbox_mutex is
> locked. This should be noted here.

OK, I will add notes in the next version.

Best regards,
Sandor
>
> Best regards,
> Alexander
>
> > +/* General commands helper functions */ int cdns_mhdp_reg_read(struct
> > +cdns_mhdp_base *base, u32 addr, u32 *value); int
> > +cdns_mhdp_reg_write(struct cdns_mhdp_base *base, u32 addr, u32 val);
> > +
> > +/* DPTX commands helper functions */
> > +int cdns_mhdp_dp_reg_write(struct cdns_mhdp_base *base, u16 addr,
> u32
> > +val); int cdns_mhdp_dp_reg_write_bit(struct cdns_mhdp_base *base, u16
> > +addr, +
>
> >       u8 start_bit, u8 bits_no, u32 val);
> > +int cdns_mhdp_dpcd_read(struct cdns_mhdp_base *base,
> > +                     u32 addr, u8 *data, u16 len); int
> > +cdns_mhdp_dpcd_write(struct cdns_mhdp_base *base, u32 addr, u8
> > +value);
> > +
> > +#endif /* __CDNS_MHDP_HELPER_H__ */
>
>
> --
> TQ-Systems GmbH | Mühlstraße 2, Gut Delling | 82229 Seefeld, Germany
> Amtsgericht München, HRB 105018
> Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider
> http://www.tq/
> -group.com%2F&data=05%7C01%7CSandor.yu%40nxp.com%7C7dae84b9c73
> 944b20c8308dbcef85e20%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7
> C0%7C638331338392509262%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4
> wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%
> 7C%7C%7C&sdata=enWq7M9EPSL8b6P%2BlNDyeoQ9oceS%2FkVtW7CqakrO
> GU0%3D&reserved=0
>
  

Patch

diff --git a/drivers/gpu/drm/bridge/cadence/Kconfig b/drivers/gpu/drm/bridge/cadence/Kconfig
index ec35215a20034..0b7b4626a7af0 100644
--- a/drivers/gpu/drm/bridge/cadence/Kconfig
+++ b/drivers/gpu/drm/bridge/cadence/Kconfig
@@ -20,6 +20,9 @@  config DRM_CDNS_DSI_J721E
 	  the routing of the DSS DPI signal to the Cadence DSI.
 endif
 
+config CDNS_MHDP_HELPER
+	tristate
+
 config DRM_CDNS_MHDP8546
 	tristate "Cadence DPI/DP bridge"
 	select DRM_DISPLAY_DP_HELPER
@@ -27,6 +30,7 @@  config DRM_CDNS_MHDP8546
 	select DRM_DISPLAY_HELPER
 	select DRM_KMS_HELPER
 	select DRM_PANEL_BRIDGE
+	select CDNS_MHDP_HELPER
 	depends on OF
 	help
 	  Support Cadence DPI to DP bridge. This is an internal
diff --git a/drivers/gpu/drm/bridge/cadence/Makefile b/drivers/gpu/drm/bridge/cadence/Makefile
index c95fd5b81d137..087dc074820d7 100644
--- a/drivers/gpu/drm/bridge/cadence/Makefile
+++ b/drivers/gpu/drm/bridge/cadence/Makefile
@@ -2,6 +2,7 @@ 
 obj-$(CONFIG_DRM_CDNS_DSI) += cdns-dsi.o
 cdns-dsi-y := cdns-dsi-core.o
 cdns-dsi-$(CONFIG_DRM_CDNS_DSI_J721E) += cdns-dsi-j721e.o
+obj-$(CONFIG_CDNS_MHDP_HELPER) += cdns-mhdp-helper.o
 obj-$(CONFIG_DRM_CDNS_MHDP8546) += cdns-mhdp8546.o
 cdns-mhdp8546-y := cdns-mhdp8546-core.o cdns-mhdp8546-hdcp.o
 cdns-mhdp8546-$(CONFIG_DRM_CDNS_MHDP8546_J721E) += cdns-mhdp8546-j721e.o
diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp-helper.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp-helper.c
new file mode 100644
index 0000000000000..8cabd79ad9663
--- /dev/null
+++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp-helper.c
@@ -0,0 +1,304 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023 NXP Semiconductor, Inc.
+ *
+ */
+#include <drm/bridge/cdns-mhdp-helper.h>
+#include <linux/dev_printk.h>
+#include <linux/module.h>
+
+/* Mailbox helper functions */
+static int cdns_mhdp_mailbox_read(struct cdns_mhdp_base *base)
+{
+	int ret, empty;
+
+	WARN_ON(!mutex_is_locked(base->mbox_mutex));
+
+	ret = readx_poll_timeout(readl, base->regs + CDNS_MAILBOX_EMPTY,
+				 empty, !empty, MAILBOX_RETRY_US,
+				 MAILBOX_TIMEOUT_US);
+	if (ret < 0)
+		return ret;
+
+	return readl(base->regs + CDNS_MAILBOX_RX_DATA) & 0xff;
+}
+
+static int cdns_mhdp_mailbox_write(struct cdns_mhdp_base *base, u8 val)
+{
+	int ret, full;
+
+	WARN_ON(!mutex_is_locked(base->mbox_mutex));
+
+	ret = readx_poll_timeout(readl, base->regs + CDNS_MAILBOX_FULL,
+				 full, !full, MAILBOX_RETRY_US,
+				 MAILBOX_TIMEOUT_US);
+	if (ret < 0)
+		return ret;
+
+	writel(val, base->regs + CDNS_MAILBOX_TX_DATA);
+
+	return 0;
+}
+
+int cdns_mhdp_mailbox_recv_header(struct cdns_mhdp_base *base,
+				  u8 module_id, u8 opcode,
+				  u16 req_size)
+{
+	u32 mbox_size, i;
+	u8 header[4];
+	int ret;
+
+	/* read the header of the message */
+	for (i = 0; i < sizeof(header); i++) {
+		ret = cdns_mhdp_mailbox_read(base);
+		if (ret < 0)
+			return ret;
+
+		header[i] = ret;
+	}
+
+	mbox_size = get_unaligned_be16(header + 2);
+
+	if (opcode != header[0] || module_id != header[1] ||
+	    req_size != mbox_size) {
+		/*
+		 * If the message in mailbox is not what we want, we need to
+		 * clear the mailbox by reading its contents.
+		 */
+		for (i = 0; i < mbox_size; i++)
+			if (cdns_mhdp_mailbox_read(base) < 0)
+				break;
+
+		return -EINVAL;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cdns_mhdp_mailbox_recv_header);
+
+int cdns_mhdp_mailbox_recv_data(struct cdns_mhdp_base *base,
+				u8 *buff, u16 buff_size)
+{
+	u32 i;
+	int ret;
+
+	for (i = 0; i < buff_size; i++) {
+		ret = cdns_mhdp_mailbox_read(base);
+		if (ret < 0)
+			return ret;
+
+		buff[i] = ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cdns_mhdp_mailbox_recv_data);
+
+int cdns_mhdp_mailbox_send(struct cdns_mhdp_base *base, u8 module_id,
+			   u8 opcode, u16 size, u8 *message)
+{
+	u8 header[4];
+	int ret, i;
+
+	header[0] = opcode;
+	header[1] = module_id;
+	put_unaligned_be16(size, header + 2);
+
+	for (i = 0; i < sizeof(header); i++) {
+		ret = cdns_mhdp_mailbox_write(base, header[i]);
+		if (ret)
+			return ret;
+	}
+
+	for (i = 0; i < size; i++) {
+		ret = cdns_mhdp_mailbox_write(base, message[i]);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cdns_mhdp_mailbox_send);
+
+/* General helper functions */
+int cdns_mhdp_reg_read(struct cdns_mhdp_base *base, u32 addr, u32 *value)
+{
+	u8 msg[4], resp[8];
+	int ret;
+
+	put_unaligned_be32(addr, msg);
+
+	mutex_lock(base->mbox_mutex);
+
+	ret = cdns_mhdp_mailbox_send(base, MB_MODULE_ID_GENERAL,
+				     GENERAL_REGISTER_READ,
+				     sizeof(msg), msg);
+	if (ret)
+		goto out;
+
+	ret = cdns_mhdp_mailbox_recv_header(base, MB_MODULE_ID_GENERAL,
+					    GENERAL_REGISTER_READ,
+					    sizeof(resp));
+	if (ret)
+		goto out;
+
+	ret = cdns_mhdp_mailbox_recv_data(base, resp, sizeof(resp));
+	if (ret)
+		goto out;
+
+	/* Returned address value should be the same as requested */
+	if (memcmp(msg, resp, sizeof(msg))) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	*value = get_unaligned_be32(resp + 4);
+
+out:
+	mutex_unlock(base->mbox_mutex);
+	if (ret) {
+		dev_err(base->dev, "Failed to read register\n");
+		*value = 0;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cdns_mhdp_reg_read);
+
+int cdns_mhdp_reg_write(struct cdns_mhdp_base *base, u32 addr, u32 val)
+{
+	u8 msg[8];
+	int ret;
+
+	put_unaligned_be32(addr, msg);
+	put_unaligned_be32(val, msg + 4);
+
+	mutex_lock(base->mbox_mutex);
+
+	ret = cdns_mhdp_mailbox_send(base, MB_MODULE_ID_GENERAL,
+				     GENERAL_REGISTER_WRITE,
+				     sizeof(msg), msg);
+
+	mutex_unlock(base->mbox_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cdns_mhdp_reg_write);
+
+/* DPTX helper functions */
+int cdns_mhdp_dp_reg_write(struct cdns_mhdp_base *base, u16 addr, u32 val)
+{
+	u8 msg[6];
+	int ret;
+
+	put_unaligned_be16(addr, msg);
+	put_unaligned_be32(val, msg + 2);
+
+	mutex_lock(base->mbox_mutex);
+
+	ret = cdns_mhdp_mailbox_send(base, MB_MODULE_ID_DP_TX,
+				     DPTX_WRITE_REGISTER, sizeof(msg), msg);
+
+	mutex_unlock(base->mbox_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cdns_mhdp_dp_reg_write);
+
+int cdns_mhdp_dp_reg_write_bit(struct cdns_mhdp_base *base, u16 addr,
+			       u8 start_bit, u8 bits_no, u32 val)
+{
+	u8 field[8];
+	int ret;
+
+	put_unaligned_be16(addr, field);
+	field[2] = start_bit;
+	field[3] = bits_no;
+	put_unaligned_be32(val, field + 4);
+
+	mutex_lock(base->mbox_mutex);
+
+	ret = cdns_mhdp_mailbox_send(base, MB_MODULE_ID_DP_TX,
+				     DPTX_WRITE_FIELD, sizeof(field), field);
+
+	mutex_unlock(base->mbox_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cdns_mhdp_dp_reg_write_bit);
+
+int cdns_mhdp_dpcd_read(struct cdns_mhdp_base *base,
+			u32 addr, u8 *data, u16 len)
+{
+	u8 msg[5], reg[5];
+	int ret;
+
+	put_unaligned_be16(len, msg);
+	put_unaligned_be24(addr, msg + 2);
+
+	mutex_lock(base->mbox_mutex);
+
+	ret = cdns_mhdp_mailbox_send(base, MB_MODULE_ID_DP_TX,
+				     DPTX_READ_DPCD, sizeof(msg), msg);
+	if (ret)
+		goto out;
+
+	ret = cdns_mhdp_mailbox_recv_header(base, MB_MODULE_ID_DP_TX,
+					    DPTX_READ_DPCD,
+					    sizeof(reg) + len);
+	if (ret)
+		goto out;
+
+	ret = cdns_mhdp_mailbox_recv_data(base, reg, sizeof(reg));
+	if (ret)
+		goto out;
+
+	ret = cdns_mhdp_mailbox_recv_data(base, data, len);
+
+out:
+	mutex_unlock(base->mbox_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cdns_mhdp_dpcd_read);
+
+int cdns_mhdp_dpcd_write(struct cdns_mhdp_base *base, u32 addr, u8 value)
+{
+	u8 msg[6], reg[5];
+	int ret;
+
+	put_unaligned_be16(1, msg);
+	put_unaligned_be24(addr, msg + 2);
+	msg[5] = value;
+
+	mutex_lock(base->mbox_mutex);
+
+	ret = cdns_mhdp_mailbox_send(base, MB_MODULE_ID_DP_TX,
+				     DPTX_WRITE_DPCD, sizeof(msg), msg);
+	if (ret)
+		goto out;
+
+	ret = cdns_mhdp_mailbox_recv_header(base, MB_MODULE_ID_DP_TX,
+					    DPTX_WRITE_DPCD, sizeof(reg));
+	if (ret)
+		goto out;
+
+	ret = cdns_mhdp_mailbox_recv_data(base, reg, sizeof(reg));
+	if (ret)
+		goto out;
+
+	if (addr != get_unaligned_be24(reg + 2))
+		ret = -EINVAL;
+
+out:
+	mutex_unlock(base->mbox_mutex);
+
+	if (ret)
+		dev_err(base->dev, "dpcd write failed: %d\n", ret);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cdns_mhdp_dpcd_write);
+
+MODULE_DESCRIPTION("Cadence MHDP Helper driver");
+MODULE_AUTHOR("Sandor Yu <Sandor.yu@nxp.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
index 6af565ac307ae..9d9dbb976868c 100644
--- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
+++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
@@ -73,298 +73,28 @@  static void cdns_mhdp_bridge_hpd_disable(struct drm_bridge *bridge)
 	       mhdp->regs + CDNS_APB_INT_MASK);
 }
 
-static int cdns_mhdp_mailbox_read(struct cdns_mhdp_device *mhdp)
-{
-	int ret, empty;
-
-	WARN_ON(!mutex_is_locked(&mhdp->mbox_mutex));
-
-	ret = readx_poll_timeout(readl, mhdp->regs + CDNS_MAILBOX_EMPTY,
-				 empty, !empty, MAILBOX_RETRY_US,
-				 MAILBOX_TIMEOUT_US);
-	if (ret < 0)
-		return ret;
-
-	return readl(mhdp->regs + CDNS_MAILBOX_RX_DATA) & 0xff;
-}
-
-static int cdns_mhdp_mailbox_write(struct cdns_mhdp_device *mhdp, u8 val)
-{
-	int ret, full;
-
-	WARN_ON(!mutex_is_locked(&mhdp->mbox_mutex));
-
-	ret = readx_poll_timeout(readl, mhdp->regs + CDNS_MAILBOX_FULL,
-				 full, !full, MAILBOX_RETRY_US,
-				 MAILBOX_TIMEOUT_US);
-	if (ret < 0)
-		return ret;
-
-	writel(val, mhdp->regs + CDNS_MAILBOX_TX_DATA);
-
-	return 0;
-}
-
-static int cdns_mhdp_mailbox_recv_header(struct cdns_mhdp_device *mhdp,
-					 u8 module_id, u8 opcode,
-					 u16 req_size)
-{
-	u32 mbox_size, i;
-	u8 header[4];
-	int ret;
-
-	/* read the header of the message */
-	for (i = 0; i < sizeof(header); i++) {
-		ret = cdns_mhdp_mailbox_read(mhdp);
-		if (ret < 0)
-			return ret;
-
-		header[i] = ret;
-	}
-
-	mbox_size = get_unaligned_be16(header + 2);
-
-	if (opcode != header[0] || module_id != header[1] ||
-	    req_size != mbox_size) {
-		/*
-		 * If the message in mailbox is not what we want, we need to
-		 * clear the mailbox by reading its contents.
-		 */
-		for (i = 0; i < mbox_size; i++)
-			if (cdns_mhdp_mailbox_read(mhdp) < 0)
-				break;
-
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
-static int cdns_mhdp_mailbox_recv_data(struct cdns_mhdp_device *mhdp,
-				       u8 *buff, u16 buff_size)
-{
-	u32 i;
-	int ret;
-
-	for (i = 0; i < buff_size; i++) {
-		ret = cdns_mhdp_mailbox_read(mhdp);
-		if (ret < 0)
-			return ret;
-
-		buff[i] = ret;
-	}
-
-	return 0;
-}
-
-static int cdns_mhdp_mailbox_send(struct cdns_mhdp_device *mhdp, u8 module_id,
-				  u8 opcode, u16 size, u8 *message)
-{
-	u8 header[4];
-	int ret, i;
-
-	header[0] = opcode;
-	header[1] = module_id;
-	put_unaligned_be16(size, header + 2);
-
-	for (i = 0; i < sizeof(header); i++) {
-		ret = cdns_mhdp_mailbox_write(mhdp, header[i]);
-		if (ret)
-			return ret;
-	}
-
-	for (i = 0; i < size; i++) {
-		ret = cdns_mhdp_mailbox_write(mhdp, message[i]);
-		if (ret)
-			return ret;
-	}
-
-	return 0;
-}
-
-static
-int cdns_mhdp_reg_read(struct cdns_mhdp_device *mhdp, u32 addr, u32 *value)
-{
-	u8 msg[4], resp[8];
-	int ret;
-
-	put_unaligned_be32(addr, msg);
-
-	mutex_lock(&mhdp->mbox_mutex);
-
-	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_GENERAL,
-				     GENERAL_REGISTER_READ,
-				     sizeof(msg), msg);
-	if (ret)
-		goto out;
-
-	ret = cdns_mhdp_mailbox_recv_header(mhdp, MB_MODULE_ID_GENERAL,
-					    GENERAL_REGISTER_READ,
-					    sizeof(resp));
-	if (ret)
-		goto out;
-
-	ret = cdns_mhdp_mailbox_recv_data(mhdp, resp, sizeof(resp));
-	if (ret)
-		goto out;
-
-	/* Returned address value should be the same as requested */
-	if (memcmp(msg, resp, sizeof(msg))) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	*value = get_unaligned_be32(resp + 4);
-
-out:
-	mutex_unlock(&mhdp->mbox_mutex);
-	if (ret) {
-		dev_err(mhdp->dev, "Failed to read register\n");
-		*value = 0;
-	}
-
-	return ret;
-}
-
-static
-int cdns_mhdp_reg_write(struct cdns_mhdp_device *mhdp, u16 addr, u32 val)
-{
-	u8 msg[6];
-	int ret;
-
-	put_unaligned_be16(addr, msg);
-	put_unaligned_be32(val, msg + 2);
-
-	mutex_lock(&mhdp->mbox_mutex);
-
-	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
-				     DPTX_WRITE_REGISTER, sizeof(msg), msg);
-
-	mutex_unlock(&mhdp->mbox_mutex);
-
-	return ret;
-}
-
 static
-int cdns_mhdp_reg_write_bit(struct cdns_mhdp_device *mhdp, u16 addr,
-			    u8 start_bit, u8 bits_no, u32 val)
-{
-	u8 field[8];
-	int ret;
-
-	put_unaligned_be16(addr, field);
-	field[2] = start_bit;
-	field[3] = bits_no;
-	put_unaligned_be32(val, field + 4);
-
-	mutex_lock(&mhdp->mbox_mutex);
-
-	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
-				     DPTX_WRITE_FIELD, sizeof(field), field);
-
-	mutex_unlock(&mhdp->mbox_mutex);
-
-	return ret;
-}
-
-static
-int cdns_mhdp_dpcd_read(struct cdns_mhdp_device *mhdp,
-			u32 addr, u8 *data, u16 len)
-{
-	u8 msg[5], reg[5];
-	int ret;
-
-	put_unaligned_be16(len, msg);
-	put_unaligned_be24(addr, msg + 2);
-
-	mutex_lock(&mhdp->mbox_mutex);
-
-	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
-				     DPTX_READ_DPCD, sizeof(msg), msg);
-	if (ret)
-		goto out;
-
-	ret = cdns_mhdp_mailbox_recv_header(mhdp, MB_MODULE_ID_DP_TX,
-					    DPTX_READ_DPCD,
-					    sizeof(reg) + len);
-	if (ret)
-		goto out;
-
-	ret = cdns_mhdp_mailbox_recv_data(mhdp, reg, sizeof(reg));
-	if (ret)
-		goto out;
-
-	ret = cdns_mhdp_mailbox_recv_data(mhdp, data, len);
-
-out:
-	mutex_unlock(&mhdp->mbox_mutex);
-
-	return ret;
-}
-
-static
-int cdns_mhdp_dpcd_write(struct cdns_mhdp_device *mhdp, u32 addr, u8 value)
+int cdns_mhdp_set_firmware_active(struct cdns_mhdp_device *mhdp, bool enable)
 {
-	u8 msg[6], reg[5];
+	u8 status;
 	int ret;
 
-	put_unaligned_be16(1, msg);
-	put_unaligned_be24(addr, msg + 2);
-	msg[5] = value;
-
 	mutex_lock(&mhdp->mbox_mutex);
 
-	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
-				     DPTX_WRITE_DPCD, sizeof(msg), msg);
-	if (ret)
-		goto out;
-
-	ret = cdns_mhdp_mailbox_recv_header(mhdp, MB_MODULE_ID_DP_TX,
-					    DPTX_WRITE_DPCD, sizeof(reg));
-	if (ret)
-		goto out;
+	status = enable ? FW_ACTIVE : FW_STANDBY;
 
-	ret = cdns_mhdp_mailbox_recv_data(mhdp, reg, sizeof(reg));
+	ret = cdns_mhdp_mailbox_send(&mhdp->base, MB_MODULE_ID_GENERAL,
+				     GENERAL_MAIN_CONTROL, sizeof(status), &status);
 	if (ret)
 		goto out;
 
-	if (addr != get_unaligned_be24(reg + 2))
-		ret = -EINVAL;
-
-out:
-	mutex_unlock(&mhdp->mbox_mutex);
-
-	if (ret)
-		dev_err(mhdp->dev, "dpcd write failed: %d\n", ret);
-	return ret;
-}
-
-static
-int cdns_mhdp_set_firmware_active(struct cdns_mhdp_device *mhdp, bool enable)
-{
-	u8 msg[5];
-	int ret, i;
-
-	msg[0] = GENERAL_MAIN_CONTROL;
-	msg[1] = MB_MODULE_ID_GENERAL;
-	msg[2] = 0;
-	msg[3] = 1;
-	msg[4] = enable ? FW_ACTIVE : FW_STANDBY;
-
-	mutex_lock(&mhdp->mbox_mutex);
-
-	for (i = 0; i < sizeof(msg); i++) {
-		ret = cdns_mhdp_mailbox_write(mhdp, msg[i]);
-		if (ret)
-			goto out;
-	}
-
-	/* read the firmware state */
-	ret = cdns_mhdp_mailbox_recv_data(mhdp, msg, sizeof(msg));
+	ret = cdns_mhdp_mailbox_recv_header(&mhdp->base, MB_MODULE_ID_GENERAL,
+					    GENERAL_MAIN_CONTROL,
+					    sizeof(status));
 	if (ret)
 		goto out;
 
-	ret = 0;
+	ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, &status, sizeof(status));
 
 out:
 	mutex_unlock(&mhdp->mbox_mutex);
@@ -382,18 +112,18 @@  int cdns_mhdp_get_hpd_status(struct cdns_mhdp_device *mhdp)
 
 	mutex_lock(&mhdp->mbox_mutex);
 
-	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
+	ret = cdns_mhdp_mailbox_send(&mhdp->base, MB_MODULE_ID_DP_TX,
 				     DPTX_HPD_STATE, 0, NULL);
 	if (ret)
 		goto err_get_hpd;
 
-	ret = cdns_mhdp_mailbox_recv_header(mhdp, MB_MODULE_ID_DP_TX,
+	ret = cdns_mhdp_mailbox_recv_header(&mhdp->base, MB_MODULE_ID_DP_TX,
 					    DPTX_HPD_STATE,
 					    sizeof(status));
 	if (ret)
 		goto err_get_hpd;
 
-	ret = cdns_mhdp_mailbox_recv_data(mhdp, &status, sizeof(status));
+	ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, &status, sizeof(status));
 	if (ret)
 		goto err_get_hpd;
 
@@ -424,22 +154,22 @@  int cdns_mhdp_get_edid_block(void *data, u8 *edid,
 		msg[0] = block / 2;
 		msg[1] = block % 2;
 
-		ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
+		ret = cdns_mhdp_mailbox_send(&mhdp->base, MB_MODULE_ID_DP_TX,
 					     DPTX_GET_EDID, sizeof(msg), msg);
 		if (ret)
 			continue;
 
-		ret = cdns_mhdp_mailbox_recv_header(mhdp, MB_MODULE_ID_DP_TX,
+		ret = cdns_mhdp_mailbox_recv_header(&mhdp->base, MB_MODULE_ID_DP_TX,
 						    DPTX_GET_EDID,
 						    sizeof(reg) + length);
 		if (ret)
 			continue;
 
-		ret = cdns_mhdp_mailbox_recv_data(mhdp, reg, sizeof(reg));
+		ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, reg, sizeof(reg));
 		if (ret)
 			continue;
 
-		ret = cdns_mhdp_mailbox_recv_data(mhdp, edid, length);
+		ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, edid, length);
 		if (ret)
 			continue;
 
@@ -464,17 +194,17 @@  int cdns_mhdp_read_hpd_event(struct cdns_mhdp_device *mhdp)
 
 	mutex_lock(&mhdp->mbox_mutex);
 
-	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
+	ret = cdns_mhdp_mailbox_send(&mhdp->base, MB_MODULE_ID_DP_TX,
 				     DPTX_READ_EVENT, 0, NULL);
 	if (ret)
 		goto out;
 
-	ret = cdns_mhdp_mailbox_recv_header(mhdp, MB_MODULE_ID_DP_TX,
+	ret = cdns_mhdp_mailbox_recv_header(&mhdp->base, MB_MODULE_ID_DP_TX,
 					    DPTX_READ_EVENT, sizeof(event));
 	if (ret < 0)
 		goto out;
 
-	ret = cdns_mhdp_mailbox_recv_data(mhdp, &event, sizeof(event));
+	ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, &event, sizeof(event));
 out:
 	mutex_unlock(&mhdp->mbox_mutex);
 
@@ -512,20 +242,20 @@  int cdns_mhdp_adjust_lt(struct cdns_mhdp_device *mhdp, unsigned int nlanes,
 
 	mutex_lock(&mhdp->mbox_mutex);
 
-	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
+	ret = cdns_mhdp_mailbox_send(&mhdp->base, MB_MODULE_ID_DP_TX,
 				     DPTX_ADJUST_LT,
 				     sizeof(payload), payload);
 	if (ret)
 		goto out;
 
 	/* Yes, read the DPCD read command response */
-	ret = cdns_mhdp_mailbox_recv_header(mhdp, MB_MODULE_ID_DP_TX,
+	ret = cdns_mhdp_mailbox_recv_header(&mhdp->base, MB_MODULE_ID_DP_TX,
 					    DPTX_READ_DPCD,
 					    sizeof(hdr) + DP_LINK_STATUS_SIZE);
 	if (ret)
 		goto out;
 
-	ret = cdns_mhdp_mailbox_recv_data(mhdp, hdr, sizeof(hdr));
+	ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, hdr, sizeof(hdr));
 	if (ret)
 		goto out;
 
@@ -533,7 +263,7 @@  int cdns_mhdp_adjust_lt(struct cdns_mhdp_device *mhdp, unsigned int nlanes,
 	if (addr != DP_LANE0_1_STATUS)
 		goto out;
 
-	ret = cdns_mhdp_mailbox_recv_data(mhdp, link_status,
+	ret = cdns_mhdp_mailbox_recv_data(&mhdp->base, link_status,
 					  DP_LINK_STATUS_SIZE);
 
 out:
@@ -847,7 +577,7 @@  static ssize_t cdns_mhdp_transfer(struct drm_dp_aux *aux,
 		unsigned int i;
 
 		for (i = 0; i < msg->size; ++i) {
-			ret = cdns_mhdp_dpcd_write(mhdp,
+			ret = cdns_mhdp_dpcd_write(&mhdp->base,
 						   msg->address + i, buf[i]);
 			if (!ret)
 				continue;
@@ -859,7 +589,7 @@  static ssize_t cdns_mhdp_transfer(struct drm_dp_aux *aux,
 			return ret;
 		}
 	} else {
-		ret = cdns_mhdp_dpcd_read(mhdp, msg->address,
+		ret = cdns_mhdp_dpcd_read(&mhdp->base, msg->address,
 					  msg->buffer, msg->size);
 		if (ret) {
 			dev_err(mhdp->dev,
@@ -887,12 +617,12 @@  static int cdns_mhdp_link_training_init(struct cdns_mhdp_device *mhdp)
 	if (!mhdp->host.scrambler)
 		reg32 |= CDNS_PHY_SCRAMBLER_BYPASS;
 
-	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_PHY_CONFIG, reg32);
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_PHY_CONFIG, reg32);
 
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_ENHNCD,
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_ENHNCD,
 			    mhdp->sink.enhanced & mhdp->host.enhanced);
 
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_LANE_EN,
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_LANE_EN,
 			    CDNS_DP_LANE_EN_LANES(mhdp->link.num_lanes));
 
 	cdns_mhdp_link_configure(&mhdp->aux, &mhdp->link);
@@ -913,7 +643,7 @@  static int cdns_mhdp_link_training_init(struct cdns_mhdp_device *mhdp)
 		return ret;
 	}
 
-	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_PHY_CONFIG,
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_PHY_CONFIG,
 			    CDNS_PHY_COMMON_CONFIG |
 			    CDNS_PHY_TRAINING_EN |
 			    CDNS_PHY_TRAINING_TYPE(1) |
@@ -1058,7 +788,7 @@  static bool cdns_mhdp_link_training_channel_eq(struct cdns_mhdp_device *mhdp,
 		CDNS_PHY_TRAINING_TYPE(eq_tps);
 	if (eq_tps != 4)
 		reg32 |= CDNS_PHY_SCRAMBLER_BYPASS;
-	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_PHY_CONFIG, reg32);
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_PHY_CONFIG, reg32);
 
 	drm_dp_dpcd_writeb(&mhdp->aux, DP_TRAINING_PATTERN_SET,
 			   (eq_tps != 4) ? eq_tps | DP_LINK_SCRAMBLING_DISABLE :
@@ -1322,7 +1052,7 @@  static int cdns_mhdp_link_training(struct cdns_mhdp_device *mhdp,
 			   mhdp->host.scrambler ? 0 :
 			   DP_LINK_SCRAMBLING_DISABLE);
 
-	ret = cdns_mhdp_reg_read(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, &reg32);
+	ret = cdns_mhdp_reg_read(&mhdp->base, CDNS_DP_FRAMER_GLOBAL_CONFIG, &reg32);
 	if (ret < 0) {
 		dev_err(mhdp->dev,
 			"Failed to read CDNS_DP_FRAMER_GLOBAL_CONFIG %d\n",
@@ -1333,13 +1063,13 @@  static int cdns_mhdp_link_training(struct cdns_mhdp_device *mhdp,
 	reg32 |= CDNS_DP_NUM_LANES(mhdp->link.num_lanes);
 	reg32 |= CDNS_DP_WR_FAILING_EDGE_VSYNC;
 	reg32 |= CDNS_DP_FRAMER_EN;
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, reg32);
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_FRAMER_GLOBAL_CONFIG, reg32);
 
 	/* Reset PHY config */
 	reg32 = CDNS_PHY_COMMON_CONFIG | CDNS_PHY_TRAINING_TYPE(1);
 	if (!mhdp->host.scrambler)
 		reg32 |= CDNS_PHY_SCRAMBLER_BYPASS;
-	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_PHY_CONFIG, reg32);
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_PHY_CONFIG, reg32);
 
 	return 0;
 err:
@@ -1347,7 +1077,7 @@  static int cdns_mhdp_link_training(struct cdns_mhdp_device *mhdp,
 	reg32 = CDNS_PHY_COMMON_CONFIG | CDNS_PHY_TRAINING_TYPE(1);
 	if (!mhdp->host.scrambler)
 		reg32 |= CDNS_PHY_SCRAMBLER_BYPASS;
-	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_PHY_CONFIG, reg32);
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_PHY_CONFIG, reg32);
 
 	drm_dp_dpcd_writeb(&mhdp->aux, DP_TRAINING_PATTERN_SET,
 			   DP_TRAINING_PATTERN_DISABLE);
@@ -1461,7 +1191,7 @@  static int cdns_mhdp_link_up(struct cdns_mhdp_device *mhdp)
 	mhdp->link.num_lanes = cdns_mhdp_max_num_lanes(mhdp);
 
 	/* Disable framer for link training */
-	err = cdns_mhdp_reg_read(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, &resp);
+	err = cdns_mhdp_reg_read(&mhdp->base, CDNS_DP_FRAMER_GLOBAL_CONFIG, &resp);
 	if (err < 0) {
 		dev_err(mhdp->dev,
 			"Failed to read CDNS_DP_FRAMER_GLOBAL_CONFIG %d\n",
@@ -1470,7 +1200,7 @@  static int cdns_mhdp_link_up(struct cdns_mhdp_device *mhdp)
 	}
 
 	resp &= ~CDNS_DP_FRAMER_EN;
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, resp);
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_FRAMER_GLOBAL_CONFIG, resp);
 
 	/* Spread AMP if required, enable 8b/10b coding */
 	amp[0] = cdns_mhdp_get_ssc_supported(mhdp) ? DP_SPREAD_AMP_0_5 : 0;
@@ -1837,7 +1567,7 @@  static void cdns_mhdp_configure_video(struct cdns_mhdp_device *mhdp,
 	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
 		bnd_hsync2vsync |= CDNS_IP_DET_INTERLACE_FORMAT;
 
-	cdns_mhdp_reg_write(mhdp, CDNS_BND_HSYNC2VSYNC(stream_id),
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_BND_HSYNC2VSYNC(stream_id),
 			    bnd_hsync2vsync);
 
 	hsync2vsync_pol_ctrl = 0;
@@ -1845,10 +1575,10 @@  static void cdns_mhdp_configure_video(struct cdns_mhdp_device *mhdp,
 		hsync2vsync_pol_ctrl |= CDNS_H2V_HSYNC_POL_ACTIVE_LOW;
 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
 		hsync2vsync_pol_ctrl |= CDNS_H2V_VSYNC_POL_ACTIVE_LOW;
-	cdns_mhdp_reg_write(mhdp, CDNS_HSYNC2VSYNC_POL_CTRL(stream_id),
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_HSYNC2VSYNC_POL_CTRL(stream_id),
 			    hsync2vsync_pol_ctrl);
 
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_PXL_REPR(stream_id), pxl_repr);
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_FRAMER_PXL_REPR(stream_id), pxl_repr);
 
 	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
 		dp_framer_sp |= CDNS_DP_FRAMER_INTERLACE;
@@ -1856,19 +1586,19 @@  static void cdns_mhdp_configure_video(struct cdns_mhdp_device *mhdp,
 		dp_framer_sp |= CDNS_DP_FRAMER_HSYNC_POL_LOW;
 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
 		dp_framer_sp |= CDNS_DP_FRAMER_VSYNC_POL_LOW;
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_SP(stream_id), dp_framer_sp);
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_FRAMER_SP(stream_id), dp_framer_sp);
 
 	front_porch = mode->crtc_hsync_start - mode->crtc_hdisplay;
 	back_porch = mode->crtc_htotal - mode->crtc_hsync_end;
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRONT_BACK_PORCH(stream_id),
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_FRONT_BACK_PORCH(stream_id),
 			    CDNS_DP_FRONT_PORCH(front_porch) |
 			    CDNS_DP_BACK_PORCH(back_porch));
 
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_BYTE_COUNT(stream_id),
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_BYTE_COUNT(stream_id),
 			    mode->crtc_hdisplay * bpp / 8);
 
 	msa_h0 = mode->crtc_htotal - mode->crtc_hsync_start;
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_HORIZONTAL_0(stream_id),
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_MSA_HORIZONTAL_0(stream_id),
 			    CDNS_DP_MSAH0_H_TOTAL(mode->crtc_htotal) |
 			    CDNS_DP_MSAH0_HSYNC_START(msa_h0));
 
@@ -1877,11 +1607,11 @@  static void cdns_mhdp_configure_video(struct cdns_mhdp_device *mhdp,
 			   CDNS_DP_MSAH1_HDISP_WIDTH(mode->crtc_hdisplay);
 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
 		msa_horizontal_1 |= CDNS_DP_MSAH1_HSYNC_POL_LOW;
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_HORIZONTAL_1(stream_id),
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_MSA_HORIZONTAL_1(stream_id),
 			    msa_horizontal_1);
 
 	msa_v0 = mode->crtc_vtotal - mode->crtc_vsync_start;
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_VERTICAL_0(stream_id),
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_MSA_VERTICAL_0(stream_id),
 			    CDNS_DP_MSAV0_V_TOTAL(mode->crtc_vtotal) |
 			    CDNS_DP_MSAV0_VSYNC_START(msa_v0));
 
@@ -1890,7 +1620,7 @@  static void cdns_mhdp_configure_video(struct cdns_mhdp_device *mhdp,
 			 CDNS_DP_MSAV1_VDISP_WIDTH(mode->crtc_vdisplay);
 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
 		msa_vertical_1 |= CDNS_DP_MSAV1_VSYNC_POL_LOW;
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_VERTICAL_1(stream_id),
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_MSA_VERTICAL_1(stream_id),
 			    msa_vertical_1);
 
 	if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
@@ -1902,14 +1632,14 @@  static void cdns_mhdp_configure_video(struct cdns_mhdp_device *mhdp,
 	if (pxlfmt == DRM_COLOR_FORMAT_YCBCR420)
 		misc1 = CDNS_DP_TEST_VSC_SDP;
 
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_MISC(stream_id),
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_MSA_MISC(stream_id),
 			    misc0 | (misc1 << 8));
 
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_HORIZONTAL(stream_id),
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_HORIZONTAL(stream_id),
 			    CDNS_DP_H_HSYNC_WIDTH(hsync) |
 			    CDNS_DP_H_H_TOTAL(mode->crtc_hdisplay));
 
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_VERTICAL_0(stream_id),
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_VERTICAL_0(stream_id),
 			    CDNS_DP_V0_VHEIGHT(mode->crtc_vdisplay) |
 			    CDNS_DP_V0_VSTART(msa_v0));
 
@@ -1918,13 +1648,13 @@  static void cdns_mhdp_configure_video(struct cdns_mhdp_device *mhdp,
 	    mode->crtc_vtotal % 2 == 0)
 		dp_vertical_1 |= CDNS_DP_V1_VTOTAL_EVEN;
 
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_VERTICAL_1(stream_id), dp_vertical_1);
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_VERTICAL_1(stream_id), dp_vertical_1);
 
-	cdns_mhdp_reg_write_bit(mhdp, CDNS_DP_VB_ID(stream_id), 2, 1,
-				(mode->flags & DRM_MODE_FLAG_INTERLACE) ?
-				CDNS_DP_VB_ID_INTERLACED : 0);
+	cdns_mhdp_dp_reg_write_bit(&mhdp->base, CDNS_DP_VB_ID(stream_id), 2, 1,
+				   (mode->flags & DRM_MODE_FLAG_INTERLACE) ?
+				   CDNS_DP_VB_ID_INTERLACED : 0);
 
-	ret = cdns_mhdp_reg_read(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, &framer);
+	ret = cdns_mhdp_reg_read(&mhdp->base, CDNS_DP_FRAMER_GLOBAL_CONFIG, &framer);
 	if (ret < 0) {
 		dev_err(mhdp->dev,
 			"Failed to read CDNS_DP_FRAMER_GLOBAL_CONFIG %d\n",
@@ -1933,7 +1663,7 @@  static void cdns_mhdp_configure_video(struct cdns_mhdp_device *mhdp,
 	}
 	framer |= CDNS_DP_FRAMER_EN;
 	framer &= ~CDNS_DP_NO_VIDEO_MODE;
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, framer);
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_FRAMER_GLOBAL_CONFIG, framer);
 }
 
 static void cdns_mhdp_sst_enable(struct cdns_mhdp_device *mhdp,
@@ -1966,15 +1696,15 @@  static void cdns_mhdp_sst_enable(struct cdns_mhdp_device *mhdp,
 
 	mhdp->stream_id = 0;
 
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_TU,
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_FRAMER_TU,
 			    CDNS_DP_FRAMER_TU_VS(vs) |
 			    CDNS_DP_FRAMER_TU_SIZE(tu_size) |
 			    CDNS_DP_FRAMER_TU_CNT_RST_EN);
 
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_LINE_THRESH(0),
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_LINE_THRESH(0),
 			    line_thresh & GENMASK(5, 0));
 
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_STREAM_CONFIG_2(0),
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_STREAM_CONFIG_2(0),
 			    CDNS_DP_SC2_TU_VS_DIFF((tu_size - vs > 3) ?
 						   0 : tu_size - vs));
 
@@ -2009,13 +1739,13 @@  static void cdns_mhdp_atomic_enable(struct drm_bridge *bridge,
 		mhdp->info->ops->enable(mhdp);
 
 	/* Enable VIF clock for stream 0 */
-	ret = cdns_mhdp_reg_read(mhdp, CDNS_DPTX_CAR, &resp);
+	ret = cdns_mhdp_reg_read(&mhdp->base, CDNS_DPTX_CAR, &resp);
 	if (ret < 0) {
 		dev_err(mhdp->dev, "Failed to read CDNS_DPTX_CAR %d\n", ret);
 		goto out;
 	}
 
-	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_CAR,
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_CAR,
 			    resp | CDNS_VIF_CLK_EN | CDNS_VIF_CLK_RSTN);
 
 	connector = drm_atomic_get_new_connector_for_encoder(state,
@@ -2083,16 +1813,16 @@  static void cdns_mhdp_atomic_disable(struct drm_bridge *bridge,
 		cdns_mhdp_hdcp_disable(mhdp);
 
 	mhdp->bridge_enabled = false;
-	cdns_mhdp_reg_read(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, &resp);
+	cdns_mhdp_reg_read(&mhdp->base, CDNS_DP_FRAMER_GLOBAL_CONFIG, &resp);
 	resp &= ~CDNS_DP_FRAMER_EN;
 	resp |= CDNS_DP_NO_VIDEO_MODE;
-	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, resp);
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DP_FRAMER_GLOBAL_CONFIG, resp);
 
 	cdns_mhdp_link_down(mhdp);
 
 	/* Disable VIF clock for stream 0 */
-	cdns_mhdp_reg_read(mhdp, CDNS_DPTX_CAR, &resp);
-	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_CAR,
+	cdns_mhdp_reg_read(&mhdp->base, CDNS_DPTX_CAR, &resp);
+	cdns_mhdp_reg_write(&mhdp->base, CDNS_DPTX_CAR,
 			    resp & ~(CDNS_VIF_CLK_EN | CDNS_VIF_CLK_RSTN));
 
 	if (mhdp->info && mhdp->info->ops && mhdp->info->ops->disable)
@@ -2502,6 +2232,11 @@  static int cdns_mhdp_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, mhdp);
 
+	/* init base struct for access mailbox  */
+	mhdp->base.dev = mhdp->dev;
+	mhdp->base.regs = mhdp->regs;
+	mhdp->base.mbox_mutex = &mhdp->mbox_mutex;
+
 	mhdp->info = of_device_get_match_data(dev);
 
 	clk_prepare_enable(clk);
diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h
index bad2fc0c73066..f08db38c82bbd 100644
--- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h
+++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h
@@ -15,6 +15,7 @@ 
 #include <linux/mutex.h>
 #include <linux/spinlock.h>
 
+#include <drm/bridge/cdns-mhdp-helper.h>
 #include <drm/display/drm_dp_helper.h>
 #include <drm/drm_bridge.h>
 #include <drm/drm_connector.h>
@@ -27,10 +28,6 @@  struct phy;
 #define CDNS_APB_CTRL				0x00000
 #define CDNS_CPU_STALL				BIT(3)
 
-#define CDNS_MAILBOX_FULL			0x00008
-#define CDNS_MAILBOX_EMPTY			0x0000c
-#define CDNS_MAILBOX_TX_DATA			0x00010
-#define CDNS_MAILBOX_RX_DATA			0x00014
 #define CDNS_KEEP_ALIVE				0x00018
 #define CDNS_KEEP_ALIVE_MASK			GENMASK(7, 0)
 
@@ -198,45 +195,10 @@  struct phy;
 #define CDNS_DP_BYTE_COUNT(s)			(CDNS_DPTX_STREAM(s) + 0x7c)
 #define CDNS_DP_BYTE_COUNT_BYTES_IN_CHUNK_SHIFT	16
 
-/* mailbox */
-#define MAILBOX_RETRY_US			1000
-#define MAILBOX_TIMEOUT_US			2000000
-
-#define MB_OPCODE_ID				0
-#define MB_MODULE_ID				1
-#define MB_SIZE_MSB_ID				2
-#define MB_SIZE_LSB_ID				3
-#define MB_DATA_ID				4
-
-#define MB_MODULE_ID_DP_TX			0x01
-#define MB_MODULE_ID_HDCP_TX			0x07
-#define MB_MODULE_ID_HDCP_RX			0x08
-#define MB_MODULE_ID_HDCP_GENERAL		0x09
-#define MB_MODULE_ID_GENERAL			0x0a
-
-/* firmware and opcodes */
+/* firmware */
 #define FW_NAME					"cadence/mhdp8546.bin"
 #define CDNS_MHDP_IMEM				0x10000
 
-#define GENERAL_MAIN_CONTROL			0x01
-#define GENERAL_TEST_ECHO			0x02
-#define GENERAL_BUS_SETTINGS			0x03
-#define GENERAL_TEST_ACCESS			0x04
-#define GENERAL_REGISTER_READ			0x07
-
-#define DPTX_SET_POWER_MNG			0x00
-#define DPTX_GET_EDID				0x02
-#define DPTX_READ_DPCD				0x03
-#define DPTX_WRITE_DPCD				0x04
-#define DPTX_ENABLE_EVENT			0x05
-#define DPTX_WRITE_REGISTER			0x06
-#define DPTX_READ_REGISTER			0x07
-#define DPTX_WRITE_FIELD			0x08
-#define DPTX_READ_EVENT				0x0a
-#define DPTX_GET_LAST_AUX_STAUS			0x0e
-#define DPTX_HPD_STATE				0x11
-#define DPTX_ADJUST_LT				0x12
-
 #define FW_STANDBY				0
 #define FW_ACTIVE				1
 
@@ -352,6 +314,8 @@  struct cdns_mhdp_hdcp {
 };
 
 struct cdns_mhdp_device {
+	struct cdns_mhdp_base base;
+
 	void __iomem *regs;
 	void __iomem *sapb_regs;
 	void __iomem *j721e_regs;
diff --git a/include/drm/bridge/cdns-mhdp-helper.h b/include/drm/bridge/cdns-mhdp-helper.h
new file mode 100644
index 0000000000000..477e67601ee5f
--- /dev/null
+++ b/include/drm/bridge/cdns-mhdp-helper.h
@@ -0,0 +1,94 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023 NXP Semiconductor, Inc.
+ */
+#ifndef __CDNS_MHDP_HELPER_H__
+#define __CDNS_MHDP_HELPER_H__
+
+#include <asm/unaligned.h>
+#include <linux/iopoll.h>
+
+/* mailbox regs offset */
+#define CDNS_MAILBOX_FULL			0x00008
+#define CDNS_MAILBOX_EMPTY			0x0000c
+#define CDNS_MAILBOX_TX_DATA			0x00010
+#define CDNS_MAILBOX_RX_DATA			0x00014
+
+#define MAILBOX_RETRY_US			1000
+#define MAILBOX_TIMEOUT_US			2000000
+
+/* Module ID Code */
+#define MB_MODULE_ID_DP_TX			0x01
+#define MB_MODULE_ID_HDMI_TX			0x03
+#define MB_MODULE_ID_HDCP_TX			0x07
+#define MB_MODULE_ID_HDCP_RX			0x08
+#define MB_MODULE_ID_HDCP_GENERAL		0x09
+#define MB_MODULE_ID_GENERAL			0x0A
+
+/* General Commands */
+#define GENERAL_MAIN_CONTROL			0x01
+#define GENERAL_TEST_ECHO			0x02
+#define GENERAL_BUS_SETTINGS			0x03
+#define GENERAL_TEST_ACCESS			0x04
+#define GENERAL_REGISTER_WRITE			0x05
+#define GENERAL_WRITE_FIELD			0x06
+#define GENERAL_REGISTER_READ			0x07
+#define GENERAL_GET_HPD_STATE			0x11
+
+/* DPTX Commands */
+#define DPTX_SET_POWER_MNG			0x00
+#define DPTX_SET_HOST_CAPABILITIES		0x01
+#define DPTX_GET_EDID				0x02
+#define DPTX_READ_DPCD				0x03
+#define DPTX_WRITE_DPCD				0x04
+#define DPTX_ENABLE_EVENT			0x05
+#define DPTX_WRITE_REGISTER			0x06
+#define DPTX_READ_REGISTER			0x07
+#define DPTX_WRITE_FIELD			0x08
+#define DPTX_TRAINING_CONTROL			0x09
+#define DPTX_READ_EVENT				0x0a
+#define DPTX_READ_LINK_STAT			0x0b
+#define DPTX_SET_VIDEO				0x0c
+#define DPTX_SET_AUDIO				0x0d
+#define DPTX_GET_LAST_AUX_STAUS			0x0e
+#define DPTX_SET_LINK_BREAK_POINT		0x0f
+#define DPTX_FORCE_LANES			0x10
+#define DPTX_HPD_STATE				0x11
+#define DPTX_ADJUST_LT				0x12
+
+/* HDMI TX Commands */
+#define HDMI_TX_READ				0x00
+#define HDMI_TX_WRITE				0x01
+#define HDMI_TX_UPDATE_READ			0x02
+#define HDMI_TX_EDID				0x03
+#define HDMI_TX_EVENTS				0x04
+#define HDMI_TX_HPD_STATUS			0x05
+
+struct cdns_mhdp_base {
+	struct device *dev;
+	void __iomem *regs;
+	/* protect mailbox communications with the firmware */
+	struct mutex *mbox_mutex;
+};
+
+/* Mailbox helper functions */
+int cdns_mhdp_mailbox_send(struct cdns_mhdp_base *base, u8 module_id,
+			   u8 opcode, u16 size, u8 *message);
+int cdns_mhdp_mailbox_recv_header(struct cdns_mhdp_base *base,
+				  u8 module_id, u8 opcode, u16 req_size);
+int cdns_mhdp_mailbox_recv_data(struct cdns_mhdp_base *base,
+				u8 *buff, u16 buff_size);
+
+/* General commands helper functions */
+int cdns_mhdp_reg_read(struct cdns_mhdp_base *base, u32 addr, u32 *value);
+int cdns_mhdp_reg_write(struct cdns_mhdp_base *base, u32 addr, u32 val);
+
+/* DPTX commands helper functions */
+int cdns_mhdp_dp_reg_write(struct cdns_mhdp_base *base, u16 addr, u32 val);
+int cdns_mhdp_dp_reg_write_bit(struct cdns_mhdp_base *base, u16 addr,
+			       u8 start_bit, u8 bits_no, u32 val);
+int cdns_mhdp_dpcd_read(struct cdns_mhdp_base *base,
+			u32 addr, u8 *data, u16 len);
+int cdns_mhdp_dpcd_write(struct cdns_mhdp_base *base, u32 addr, u8 value);
+
+#endif /* __CDNS_MHDP_HELPER_H__ */