[v5,3/4] media: platform: Add Renesas RZ/G2L MIPI CSI-2 receiver driver

Message ID 20221102004329.5410-4-prabhakar.mahadev-lad.rj@bp.renesas.com
State New
Headers
Series Add driver for CSI2 and CRU modules found on Renesas RZ/G2L SoC |

Commit Message

Lad, Prabhakar Nov. 2, 2022, 12:43 a.m. UTC
  From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Add MIPI CSI-2 receiver driver for Renesas RZ/G2L. The MIPI
CSI-2 is part of the CRU module found on RZ/G2L family.

Based on a patch in the BSP by Hien Huynh
<hien.huynh.px@renesas.com>

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
v4 -> v5
* Made sure to cleanup in s_stream error path

v3 -> v4
* Implemented post_streamoff callback

v2 -> v3
* Switched to runtime PM
* Implemented pre_streamon callback in CSI driver
* Got rid of rzg2l_csi2_cmn_rstb_deassert()/
  rzg2l_csi2_dphy_setting/rzg2l_csi2_mipi_link_setting() from CSI driver
* Switched to for-loop instead of if block for getting CSI timings
* Fixed rzg2l_csi2_set_format() as pointed by Laurent
* Copied all colorspace-related fields received from userspace (colorspace,
  xfer_func, ycbcr_enc and quantization) in rzg2l_csi2_set_format.
* Initialised pad in rzg2l_csi2_init_config() 
* Introduced RZG2L_CSI2_DEFAULT_WIDTH/HEIGHT/FMT macros
* Dropped RZG2L_CSI2_SOURCE_VC0-RZG2L_CSI2_SOURCE_VC3 macros

v1 -> v2
* Sorted Kconfig select
* Prefixed generic names for struct/variables with rzg2_csi2
* Dropped unnecessary checks for remote source
* Dropped exporting functions
* Moved lane validation to probe
* Split up rzg2l_csi2_dphy_setting() and rzg2l_csi2_mipi_link_setting()
* Used rzg2l_csi2_write() wherever possible
* Dropped stream_count/lock
* Used active subdev state instead of manually storing format in driver
* Implemented init_cfg/enum_frame_size/enum_mbus_code callbacks
* Dropped check for bus_type of remote source
* Switched to manually turn ON/OFF the clocks instead of pm_runtime so that
  the mipi/dhpy initialization happens as per the HW manual
* Hardcoded VC0 usage for now as streams API is under development

RFC v2 -> v1
* Fixed initialization sequence of DPHY and link
* Exported DPHY and link initialization functions so that the
  CRU core driver can initialize the CRU and CSI2 as per the HW manual.

RFC v1 -> RFC v2
* new patch (split up as new driver compared to v1)
---
 drivers/media/platform/renesas/Kconfig        |   1 +
 drivers/media/platform/renesas/Makefile       |   1 +
 .../media/platform/renesas/rzg2l-cru/Kconfig  |  17 +
 .../media/platform/renesas/rzg2l-cru/Makefile |   3 +
 .../platform/renesas/rzg2l-cru/rzg2l-csi2.c   | 885 ++++++++++++++++++
 5 files changed, 907 insertions(+)
 create mode 100644 drivers/media/platform/renesas/rzg2l-cru/Kconfig
 create mode 100644 drivers/media/platform/renesas/rzg2l-cru/Makefile
 create mode 100644 drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c
  

Comments

Laurent Pinchart Nov. 22, 2022, 1:15 a.m. UTC | #1
Hi Prabhakar,

Thank you for the patch.

On Wed, Nov 02, 2022 at 12:43:28AM +0000, Prabhakar wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> 
> Add MIPI CSI-2 receiver driver for Renesas RZ/G2L. The MIPI
> CSI-2 is part of the CRU module found on RZ/G2L family.
> 
> Based on a patch in the BSP by Hien Huynh
> <hien.huynh.px@renesas.com>
> 
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
> v4 -> v5
> * Made sure to cleanup in s_stream error path
> 
> v3 -> v4
> * Implemented post_streamoff callback
> 
> v2 -> v3
> * Switched to runtime PM
> * Implemented pre_streamon callback in CSI driver
> * Got rid of rzg2l_csi2_cmn_rstb_deassert()/
>   rzg2l_csi2_dphy_setting/rzg2l_csi2_mipi_link_setting() from CSI driver
> * Switched to for-loop instead of if block for getting CSI timings
> * Fixed rzg2l_csi2_set_format() as pointed by Laurent
> * Copied all colorspace-related fields received from userspace (colorspace,
>   xfer_func, ycbcr_enc and quantization) in rzg2l_csi2_set_format.
> * Initialised pad in rzg2l_csi2_init_config() 
> * Introduced RZG2L_CSI2_DEFAULT_WIDTH/HEIGHT/FMT macros
> * Dropped RZG2L_CSI2_SOURCE_VC0-RZG2L_CSI2_SOURCE_VC3 macros
> 
> v1 -> v2
> * Sorted Kconfig select
> * Prefixed generic names for struct/variables with rzg2_csi2
> * Dropped unnecessary checks for remote source
> * Dropped exporting functions
> * Moved lane validation to probe
> * Split up rzg2l_csi2_dphy_setting() and rzg2l_csi2_mipi_link_setting()
> * Used rzg2l_csi2_write() wherever possible
> * Dropped stream_count/lock
> * Used active subdev state instead of manually storing format in driver
> * Implemented init_cfg/enum_frame_size/enum_mbus_code callbacks
> * Dropped check for bus_type of remote source
> * Switched to manually turn ON/OFF the clocks instead of pm_runtime so that
>   the mipi/dhpy initialization happens as per the HW manual
> * Hardcoded VC0 usage for now as streams API is under development
> 
> RFC v2 -> v1
> * Fixed initialization sequence of DPHY and link
> * Exported DPHY and link initialization functions so that the
>   CRU core driver can initialize the CRU and CSI2 as per the HW manual.
> 
> RFC v1 -> RFC v2
> * new patch (split up as new driver compared to v1)
> ---
>  drivers/media/platform/renesas/Kconfig        |   1 +
>  drivers/media/platform/renesas/Makefile       |   1 +
>  .../media/platform/renesas/rzg2l-cru/Kconfig  |  17 +
>  .../media/platform/renesas/rzg2l-cru/Makefile |   3 +
>  .../platform/renesas/rzg2l-cru/rzg2l-csi2.c   | 885 ++++++++++++++++++
>  5 files changed, 907 insertions(+)
>  create mode 100644 drivers/media/platform/renesas/rzg2l-cru/Kconfig
>  create mode 100644 drivers/media/platform/renesas/rzg2l-cru/Makefile
>  create mode 100644 drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c
> 
> diff --git a/drivers/media/platform/renesas/Kconfig b/drivers/media/platform/renesas/Kconfig
> index 9fd90672ea2d..ed788e991f74 100644
> --- a/drivers/media/platform/renesas/Kconfig
> +++ b/drivers/media/platform/renesas/Kconfig
> @@ -41,6 +41,7 @@ config VIDEO_SH_VOU
>  	  Support for the Video Output Unit (VOU) on SuperH SoCs.
>  
>  source "drivers/media/platform/renesas/rcar-vin/Kconfig"
> +source "drivers/media/platform/renesas/rzg2l-cru/Kconfig"
>  
>  # Mem2mem drivers
>  
> diff --git a/drivers/media/platform/renesas/Makefile b/drivers/media/platform/renesas/Makefile
> index 3ec226ef5fd2..55854e868887 100644
> --- a/drivers/media/platform/renesas/Makefile
> +++ b/drivers/media/platform/renesas/Makefile
> @@ -4,6 +4,7 @@
>  #
>  
>  obj-y += rcar-vin/
> +obj-y += rzg2l-cru/
>  obj-y += vsp1/
>  
>  obj-$(CONFIG_VIDEO_RCAR_DRIF) += rcar_drif.o
> diff --git a/drivers/media/platform/renesas/rzg2l-cru/Kconfig b/drivers/media/platform/renesas/rzg2l-cru/Kconfig
> new file mode 100644
> index 000000000000..57c40bb499df
> --- /dev/null
> +++ b/drivers/media/platform/renesas/rzg2l-cru/Kconfig
> @@ -0,0 +1,17 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +config VIDEO_RZG2L_CSI2
> +	tristate "RZ/G2L MIPI CSI-2 Receiver"
> +	depends on ARCH_RENESAS || COMPILE_TEST
> +	depends on V4L_PLATFORM_DRIVERS
> +	depends on VIDEO_DEV && OF
> +	select MEDIA_CONTROLLER
> +	select RESET_CONTROLLER
> +	select V4L2_FWNODE
> +	select VIDEO_V4L2_SUBDEV_API
> +	help
> +	  Support for Renesas RZ/G2L (and alike SoC's) MIPI CSI-2
> +	  Receiver driver.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called rzg2l-csi2.
> diff --git a/drivers/media/platform/renesas/rzg2l-cru/Makefile b/drivers/media/platform/renesas/rzg2l-cru/Makefile
> new file mode 100644
> index 000000000000..91ea97a944e6
> --- /dev/null
> +++ b/drivers/media/platform/renesas/rzg2l-cru/Makefile
> @@ -0,0 +1,3 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +obj-$(CONFIG_VIDEO_RZG2L_CSI2) += rzg2l-csi2.o
> diff --git a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c
> new file mode 100644
> index 000000000000..2ab9e8454a04
> --- /dev/null
> +++ b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c
> @@ -0,0 +1,885 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Driver for Renesas RZ/G2L MIPI CSI-2 Receiver
> + *
> + * Copyright (C) 2022 Renesas Electronics Corp.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/of_graph.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/reset.h>
> +#include <linux/sys_soc.h>
> +#include <linux/units.h>
> +
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-fwnode.h>
> +#include <media/v4l2-mc.h>
> +#include <media/v4l2-subdev.h>
> +
> +/* LINK registers */
> +/* Module Configuration Register */
> +#define CSI2nMCG			0x0
> +#define CSI2nMCG_SDLN			GENMASK(11, 8)
> +
> +/* Module Control Register 0 */
> +#define CSI2nMCT0			0x10
> +#define CSI2nMCT0_VDLN(x)		((x) << 0)
> +
> +/* Module Control Register 2 */
> +#define CSI2nMCT2			0x18
> +#define CSI2nMCT2_FRRSKW(x)		((x) << 16)
> +#define CSI2nMCT2_FRRCLK(x)		((x) << 0)
> +
> +/* Module Control Register 3 */
> +#define CSI2nMCT3			0x1c
> +#define CSI2nMCT3_RXEN			BIT(0)
> +
> +/* Reset Control Register */
> +#define CSI2nRTCT			0x28
> +#define CSI2nRTCT_VSRST			BIT(0)
> +
> +/* Reset Status Register */
> +#define CSI2nRTST			0x2c
> +#define CSI2nRTST_VSRSTS		BIT(0)
> +
> +/* Receive Data Type Enable Low Register */
> +#define CSI2nDTEL			0x60
> +
> +/* Receive Data Type Enable High Register */
> +#define CSI2nDTEH			0x64
> +
> +/* DPHY registers */
> +/* D-PHY Control Register 0 */
> +#define CSIDPHYCTRL0			0x400
> +#define CSIDPHYCTRL0_EN_LDO1200		BIT(1)
> +#define CSIDPHYCTRL0_EN_BGR		BIT(0)
> +
> +/* D-PHY Timing Register 0 */
> +#define CSIDPHYTIM0			0x404
> +#define CSIDPHYTIM0_TCLK_MISS(x)	((x) << 24)
> +#define CSIDPHYTIM0_T_INIT(x)		((x) << 0)
> +
> +/* D-PHY Timing Register 1 */
> +#define CSIDPHYTIM1			0x408
> +#define CSIDPHYTIM1_THS_PREPARE(x)	((x) << 24)
> +#define CSIDPHYTIM1_TCLK_PREPARE(x)	((x) << 16)
> +#define CSIDPHYTIM1_THS_SETTLE(x)	((x) << 8)
> +#define CSIDPHYTIM1_TCLK_SETTLE(x)	((x) << 0)
> +
> +/* D-PHY Skew Adjustment Function */
> +#define CSIDPHYSKW0			0x460
> +#define CSIDPHYSKW0_UTIL_DL0_SKW_ADJ(x)	((x) & 0x3)
> +#define CSIDPHYSKW0_UTIL_DL1_SKW_ADJ(x)	(((x) & 0x3) << 4)
> +#define CSIDPHYSKW0_UTIL_DL2_SKW_ADJ(x)	(((x) & 0x3) << 8)
> +#define CSIDPHYSKW0_UTIL_DL3_SKW_ADJ(x)	(((x) & 0x3) << 12)
> +#define CSIDPHYSKW0_DEFAULT_SKW		CSIDPHYSKW0_UTIL_DL0_SKW_ADJ(1) | \
> +					CSIDPHYSKW0_UTIL_DL1_SKW_ADJ(1) | \
> +					CSIDPHYSKW0_UTIL_DL2_SKW_ADJ(1) | \
> +					CSIDPHYSKW0_UTIL_DL3_SKW_ADJ(1)
> +
> +#define VSRSTS_RETRIES			20
> +
> +#define RZG2L_CSI2_MIN_WIDTH		320
> +#define RZG2L_CSI2_MIN_HEIGHT		240
> +#define RZG2L_CSI2_MAX_WIDTH		2800
> +#define RZG2L_CSI2_MAX_HEIGHT		4095
> +
> +#define RZG2L_CSI2_DEFAULT_WIDTH	RZG2L_CSI2_MIN_WIDTH
> +#define RZG2L_CSI2_DEFAULT_HEIGHT	RZG2L_CSI2_MIN_HEIGHT
> +#define RZG2L_CSI2_DEFAULT_FMT		MEDIA_BUS_FMT_UYVY8_1X16
> +
> +enum rzg2l_csi2_pads {
> +	RZG2L_CSI2_SINK = 0,
> +	RZG2L_CSI2_SOURCE,
> +	NR_OF_RZG2L_CSI2_PAD,
> +};
> +
> +struct rzg2l_csi2 {
> +	struct device *dev;
> +	void __iomem *base;
> +	struct reset_control *presetn;
> +	struct reset_control *cmn_rstb;
> +	struct clk *sysclk;
> +	unsigned long vclk_rate;
> +
> +	struct v4l2_subdev subdev;
> +	struct media_pad pads[NR_OF_RZG2L_CSI2_PAD];
> +
> +	struct v4l2_async_notifier notifier;
> +	struct v4l2_subdev *remote_source;
> +
> +	unsigned short lanes;
> +	unsigned long hsfreq;
> +
> +	bool dphy_enabled;
> +};
> +
> +struct rzg2l_csi2_timings {
> +	u32 t_init;
> +	u32 tclk_miss;
> +	u32 tclk_settle;
> +	u32 ths_settle;
> +	u32 tclk_prepare;
> +	u32 ths_prepare;
> +	u32 max_hsfreq;
> +};
> +
> +static const struct rzg2l_csi2_timings rzg2l_csi2_global_timings[] = {
> +	[0] = {

You can drop [0]. Same below.

> +		.max_hsfreq = 80,
> +		.t_init = 79801,
> +		.tclk_miss = 4,
> +		.tclk_settle = 23,
> +		.ths_settle = 31,
> +		.tclk_prepare = 10,
> +		.ths_prepare = 19,
> +	},
> +	[1] = {
> +		.max_hsfreq = 125,
> +		.t_init = 79801,
> +		.tclk_miss = 4,
> +		.tclk_settle = 23,
> +		.ths_settle = 28,
> +		.tclk_prepare = 10,
> +		.ths_prepare = 19,
> +	},
> +	[2] = {
> +		.max_hsfreq = 250,
> +		.t_init = 79801,
> +		.tclk_miss = 4,
> +		.tclk_settle = 23,
> +		.ths_settle = 22,
> +		.tclk_prepare = 10,
> +		.ths_prepare = 16,
> +	},
> +	[3] = {
> +		.max_hsfreq = 360,
> +		.t_init = 79801,
> +		.tclk_miss = 4,
> +		.tclk_settle = 18,
> +		.ths_settle = 19,
> +		.tclk_prepare = 10,
> +		.ths_prepare = 10,
> +	},
> +	[4] = {
> +		.max_hsfreq = 1500,
> +		.t_init = 79801,
> +		.tclk_miss = 4,
> +		.tclk_settle = 18,
> +		.ths_settle = 18,
> +		.tclk_prepare = 10,
> +		.ths_prepare = 10,
> +	},
> +};
> +
> +struct rzg2l_csi2_format {
> +	u32 code;
> +	unsigned int datatype;
> +	unsigned int bpp;
> +};
> +
> +static const struct rzg2l_csi2_format rzg2l_csi2_formats[] = {
> +	{ .code = MEDIA_BUS_FMT_UYVY8_1X16,	.datatype = 0x1e, .bpp = 16 },
> +};
> +
> +static inline struct rzg2l_csi2 *sd_to_csi2(struct v4l2_subdev *sd)
> +{
> +	return container_of(sd, struct rzg2l_csi2, subdev);
> +}
> +
> +static const struct rzg2l_csi2_format *rzg2l_csi2_code_to_fmt(unsigned int code)
> +{
> +	unsigned int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(rzg2l_csi2_formats); i++)
> +		if (rzg2l_csi2_formats[i].code == code)
> +			return &rzg2l_csi2_formats[i];
> +
> +	return NULL;
> +}
> +
> +static inline struct rzg2l_csi2 *notifier_to_csi2(struct v4l2_async_notifier *n)
> +{
> +	return container_of(n, struct rzg2l_csi2, notifier);
> +}
> +
> +static u32 rzg2l_csi2_read(struct rzg2l_csi2 *csi2, unsigned int reg)
> +{
> +	return ioread32(csi2->base + reg);
> +}
> +
> +static void rzg2l_csi2_write(struct rzg2l_csi2 *csi2, unsigned int reg,
> +			     u32 data)
> +{
> +	iowrite32(data, csi2->base + reg);
> +}
> +
> +static void rzg2l_csi2_set(struct rzg2l_csi2 *csi2, unsigned int reg, u32 set)
> +{
> +	rzg2l_csi2_write(csi2, reg, rzg2l_csi2_read(csi2, reg) | set);
> +}
> +
> +static void rzg2l_csi2_clr(struct rzg2l_csi2 *csi2, unsigned int reg, u32 clr)
> +{
> +	rzg2l_csi2_write(csi2, reg, rzg2l_csi2_read(csi2, reg) & ~clr);
> +}
> +
> +static int rzg2l_csi2_calc_mbps(struct rzg2l_csi2 *csi2)
> +{
> +	struct v4l2_subdev *source = csi2->remote_source;
> +	const struct rzg2l_csi2_format *format;
> +	const struct v4l2_mbus_framefmt *fmt;
> +	struct v4l2_subdev_state *state;
> +	struct v4l2_ctrl *ctrl;
> +	u64 mbps;
> +
> +	/* Read the pixel rate control from remote. */
> +	ctrl = v4l2_ctrl_find(source->ctrl_handler, V4L2_CID_PIXEL_RATE);
> +	if (!ctrl) {
> +		dev_err(csi2->dev, "no pixel rate control in subdev %s\n",
> +			source->name);
> +		return -EINVAL;
> +	}
> +
> +	state = v4l2_subdev_lock_and_get_active_state(&csi2->subdev);
> +	fmt = v4l2_subdev_get_pad_format(&csi2->subdev, state, RZG2L_CSI2_SINK);
> +	format = rzg2l_csi2_code_to_fmt(fmt->code);
> +	v4l2_subdev_unlock_state(state);
> +
> +	/*
> +	 * Calculate hsfreq in Mbps
> +	 * hsfreq = (pixel_rate * bits_per_sample) / number_of_lanes
> +	 */
> +	mbps = v4l2_ctrl_g_ctrl_int64(ctrl) * format->bpp;
> +	do_div(mbps, csi2->lanes * 1000000);
> +
> +	return mbps;
> +}
> +
> +/* -----------------------------------------------------------------------------
> + * DPHY setting
> + */
> +
> +static int rzg2l_csi2_dphy_disable(struct rzg2l_csi2 *csi2)
> +{
> +	int ret;
> +
> +	/* Reset the CRU (D-PHY) */
> +	ret = reset_control_assert(csi2->cmn_rstb);
> +	if (ret)
> +		return ret;
> +
> +	/* Stop the D-PHY clock */
> +	clk_disable_unprepare(csi2->sysclk);
> +
> +	/* Cancel the EN_LDO1200 register setting */
> +	rzg2l_csi2_clr(csi2, CSIDPHYCTRL0, CSIDPHYCTRL0_EN_LDO1200);
> +
> +	/* Cancel the EN_BGR register setting */
> +	rzg2l_csi2_clr(csi2, CSIDPHYCTRL0, CSIDPHYCTRL0_EN_BGR);
> +
> +	csi2->dphy_enabled = false;
> +
> +	return 0;
> +}
> +
> +static int rzg2l_csi2_dphy_enable(struct rzg2l_csi2 *csi2)
> +{
> +	const struct rzg2l_csi2_timings *dphy_timing;
> +	u32 dphytim0, dphytim1;
> +	unsigned int i;
> +	int mbps;
> +	int ret;
> +
> +	mbps = rzg2l_csi2_calc_mbps(csi2);
> +	if (mbps < 0)
> +		return mbps;
> +
> +	csi2->hsfreq = mbps;
> +
> +	/* Set DPHY timing parameters */
> +	for (i = 0; i < ARRAY_SIZE(rzg2l_csi2_global_timings); ++i) {
> +		dphy_timing = &rzg2l_csi2_global_timings[i];
> +
> +		if (csi2->hsfreq <= dphy_timing->max_hsfreq)
> +			break;
> +	}
> +
> +	if (i >= ARRAY_SIZE(rzg2l_csi2_global_timings))
> +		return -EINVAL;
> +
> +	/* Set D-PHY timing parameters */
> +	dphytim0 = CSIDPHYTIM0_TCLK_MISS(dphy_timing->tclk_miss) |
> +			CSIDPHYTIM0_T_INIT(dphy_timing->t_init);
> +	dphytim1 = CSIDPHYTIM1_THS_PREPARE(dphy_timing->ths_prepare) |
> +			CSIDPHYTIM1_TCLK_PREPARE(dphy_timing->tclk_prepare) |
> +			CSIDPHYTIM1_THS_SETTLE(dphy_timing->ths_settle) |
> +			CSIDPHYTIM1_TCLK_SETTLE(dphy_timing->tclk_settle);
> +	rzg2l_csi2_write(csi2, CSIDPHYTIM0, dphytim0);
> +	rzg2l_csi2_write(csi2, CSIDPHYTIM1, dphytim1);
> +
> +	/* Enable D-PHY power control 0 */
> +	rzg2l_csi2_write(csi2, CSIDPHYSKW0, CSIDPHYSKW0_DEFAULT_SKW);
> +
> +	/* Set the EN_BGR bit */
> +	rzg2l_csi2_set(csi2, CSIDPHYCTRL0, CSIDPHYCTRL0_EN_BGR);
> +
> +	/* Delay 20us to be stable */
> +	usleep_range(20, 40);
> +
> +	/* Enable D-PHY power control 1 */
> +	rzg2l_csi2_set(csi2, CSIDPHYCTRL0, CSIDPHYCTRL0_EN_LDO1200);
> +
> +	/* Delay 10us to be stable */
> +	usleep_range(10, 20);
> +
> +	/* Start supplying the internal clock for the D-PHY block */
> +	ret = clk_prepare_enable(csi2->sysclk);
> +	if (ret)
> +		rzg2l_csi2_dphy_disable(csi2);
> +
> +	csi2->dphy_enabled = true;
> +
> +	return ret;
> +}
> +
> +static int rzg2l_csi2_enable_reg_access(struct rzg2l_csi2 *csi2)
> +{
> +	int ret;
> +
> +	ret = reset_control_deassert(csi2->presetn);
> +	if (ret < 0)
> +		return ret;

Could this be done in the runtime PM resume handler ? Same for
reset_control_assert() in the runtime PM suspend handler.

> +
> +	ret = pm_runtime_resume_and_get(csi2->dev);
> +	if (ret)
> +		reset_control_assert(csi2->presetn);
> +
> +	return ret;
> +}
> +
> +static void rzg2l_csi2_disable_reg_access(struct rzg2l_csi2 *csi2)
> +{
> +	pm_runtime_put_sync(csi2->dev);
> +	reset_control_assert(csi2->presetn);
> +}
> +
> +static int rzg2l_csi2_dphy_setting(struct v4l2_subdev *sd, bool on)
> +{
> +	struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
> +	int ret;
> +
> +	ret = rzg2l_csi2_enable_reg_access(csi2);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (on)
> +		ret = rzg2l_csi2_dphy_enable(csi2);
> +	else
> +		ret = rzg2l_csi2_dphy_disable(csi2);
> +
> +	rzg2l_csi2_disable_reg_access(csi2);
> +
> +	return ret;
> +}
> +
> +static void rzg2l_csi2_mipi_link_enable(struct rzg2l_csi2 *csi2)
> +{
> +	unsigned long vclk_rate = csi2->vclk_rate / HZ_PER_MHZ;
> +	u32 frrskw, frrclk, frrskw_coeff, frrclk_coeff;
> +
> +	/* Select data lanes */
> +	rzg2l_csi2_write(csi2, CSI2nMCT0, CSI2nMCT0_VDLN(csi2->lanes));
> +
> +	frrskw_coeff = 3 * vclk_rate * 8;
> +	frrclk_coeff = frrskw_coeff / 2;
> +	frrskw = DIV_ROUND_UP(frrskw_coeff, csi2->hsfreq);
> +	frrclk = DIV_ROUND_UP(frrclk_coeff, csi2->hsfreq);
> +	rzg2l_csi2_write(csi2, CSI2nMCT2, CSI2nMCT2_FRRSKW(frrskw) |
> +			 CSI2nMCT2_FRRCLK(frrclk));
> +
> +	/*
> +	 * Select data type.
> +	 * FS, FE, LS, LE, Generic Short Packet Codes 1 to 8,
> +	 * Generic Long Packet Data Types 1 to 4 YUV422 8-bit,
> +	 * RGB565, RGB888, RAW8 to RAW20, User-defined 8-bit
> +	 * data types 1 to 8
> +	 */
> +	rzg2l_csi2_write(csi2, CSI2nDTEL, 0xf778ff0f);
> +	rzg2l_csi2_write(csi2, CSI2nDTEH, 0x00ffff1f);
> +
> +	/* Enable LINK reception */
> +	rzg2l_csi2_write(csi2, CSI2nMCT3, CSI2nMCT3_RXEN);
> +}
> +
> +static void rzg2l_csi2_mipi_link_disable(struct rzg2l_csi2 *csi2)
> +{
> +	unsigned int timeout = VSRSTS_RETRIES;
> +
> +	/* Stop LINK reception */
> +	rzg2l_csi2_clr(csi2, CSI2nMCT3, CSI2nMCT3_RXEN);
> +
> +	/* Request a software reset of the LINK Video Pixel Interface */
> +	rzg2l_csi2_write(csi2, CSI2nRTCT, CSI2nRTCT_VSRST);
> +
> +	/* Make sure CSI2nRTST.VSRSTS bit is cleared */
> +	while (timeout--) {
> +		if (!(rzg2l_csi2_read(csi2, CSI2nRTST) & CSI2nRTST_VSRSTS))
> +			break;
> +		usleep_range(100, 200);
> +	};
> +
> +	if (!timeout)
> +		dev_err(csi2->dev, "Clearing CSI2nRTST.VSRSTS timed out\n");
> +}
> +
> +static int rzg2l_csi2_mipi_link_setting(struct v4l2_subdev *sd, bool on)
> +{
> +	struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
> +	int ret;
> +
> +	ret = rzg2l_csi2_enable_reg_access(csi2);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (on)
> +		rzg2l_csi2_mipi_link_enable(csi2);
> +	else
> +		rzg2l_csi2_mipi_link_disable(csi2);
> +
> +	rzg2l_csi2_disable_reg_access(csi2);

This doesn't seem right. Runtime PM isn't just about register access.
You need to call pm_runtime_resume_and_get() at the beginning of
rzg2l_csi2_s_stream() when enabling, and pm_runtime_put_sync() at the
end of rzg2l_csi2_s_stream() when disabling (+ error paths for the
enable case).

> +
> +	return 0;
> +}
> +
> +static int rzg2l_csi2_s_stream(struct v4l2_subdev *sd, int enable)
> +{
> +	struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
> +	int s_stream_ret = 0;
> +	int ret;
> +
> +	if (enable) {
> +		int ret;
> +
> +		ret = rzg2l_csi2_mipi_link_setting(sd, 1);
> +		if (ret)
> +			return ret;
> +
> +		ret = reset_control_deassert(csi2->cmn_rstb);
> +		if (ret)
> +			goto err_mipi_link_disable;
> +	}
> +
> +	ret = v4l2_subdev_call(csi2->remote_source, video, s_stream, enable);
> +	if (ret) {
> +		s_stream_ret = ret;
> +		dev_err(csi2->dev, "s_stream failed on remote source\n");

With
https://lore.kernel.org/linux-media/20221026065123.595777-1-sakari.ailus@linux.intel.com/
I think you can drop this error message.

> +	}
> +
> +	if (enable && ret)
> +		goto err_assert_rstb;
> +
> +	if (!enable) {
> +		ret = rzg2l_csi2_dphy_setting(sd, 0);
> +		if (ret && !s_stream_ret)
> +			s_stream_ret = ret;
> +		ret = rzg2l_csi2_mipi_link_setting(sd, 0);
> +		if (ret && !s_stream_ret)
> +			s_stream_ret = ret;
> +	}
> +
> +	return s_stream_ret;
> +
> +err_assert_rstb:
> +	reset_control_assert(csi2->cmn_rstb);
> +err_mipi_link_disable:
> +	rzg2l_csi2_mipi_link_setting(sd, 0);
> +	return ret;
> +}
> +
> +static int rzg2l_csi2_pre_streamon(struct v4l2_subdev *sd, u32 flags)
> +{
> +	return rzg2l_csi2_dphy_setting(sd, 1);
> +}
> +
> +static int rzg2l_csi2_post_streamoff(struct v4l2_subdev *sd)
> +{
> +	struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
> +
> +	/*
> +	 * In ideal case D-PHY will be disabled in s_stream(0) callback
> +	 * as mentioned the HW manual. The below will only happen when
> +	 * pre_streamon succeeds and further down the line s_stream(1)
> +	 * fails so we need to undo things in post_streamoff.
> +	 */
> +	if (csi2->dphy_enabled)
> +		return rzg2l_csi2_dphy_setting(sd, 0);
> +
> +	return 0;
> +}
> +
> +static int rzg2l_csi2_set_format(struct v4l2_subdev *sd,
> +				 struct v4l2_subdev_state *state,
> +				 struct v4l2_subdev_format *fmt)
> +{
> +	struct v4l2_mbus_framefmt *src_format;
> +	struct v4l2_mbus_framefmt *sink_format;
> +
> +	if (fmt->pad != RZG2L_CSI2_SINK && fmt->pad != RZG2L_CSI2_SOURCE)
> +		return -EINVAL;

You can drop this check as the set_format wrapper validates the pad
value already.

> +
> +	sink_format = v4l2_subdev_get_pad_format(sd, state, RZG2L_CSI2_SINK);
> +	src_format = v4l2_subdev_get_pad_format(sd, state, RZG2L_CSI2_SOURCE);

As the CSI-2 receiver can't modify the format on the output,
set_format() on the source pad must not modify the format. Just add

	if (fmt->pad == RZG2L_CSI2_SOURCE) {
		fmt->format = *src_format;
		return 0;
	}

here.

> +
> +	if (!rzg2l_csi2_code_to_fmt(fmt->format.code))
> +		sink_format->code = rzg2l_csi2_formats[0].code;
> +	else
> +		sink_format->code = fmt->format.code;
> +
> +	sink_format->field = V4L2_FIELD_NONE;
> +	sink_format->colorspace = fmt->format.colorspace;
> +	sink_format->xfer_func = fmt->format.xfer_func;
> +	sink_format->ycbcr_enc = fmt->format.ycbcr_enc;
> +	sink_format->quantization = fmt->format.quantization;
> +	sink_format->width = clamp_t(u32, fmt->format.width,
> +				     RZG2L_CSI2_MIN_WIDTH, RZG2L_CSI2_MAX_WIDTH);
> +	sink_format->height = clamp_t(u32, fmt->format.height,
> +				      RZG2L_CSI2_MIN_HEIGHT, RZG2L_CSI2_MAX_HEIGHT);
> +	fmt->format = *sink_format;
> +
> +	/* propagate format to source pad */
> +	*src_format = *sink_format;
> +
> +	return 0;
> +}
> +
> +static int rzg2l_csi2_init_config(struct v4l2_subdev *sd,
> +				  struct v4l2_subdev_state *sd_state)
> +{
> +	struct v4l2_subdev_format fmt = { .pad = RZG2L_CSI2_SINK, };
> +
> +	fmt.format.width = RZG2L_CSI2_DEFAULT_WIDTH;
> +	fmt.format.height = RZG2L_CSI2_DEFAULT_HEIGHT;
> +	fmt.format.field = V4L2_FIELD_NONE;
> +	fmt.format.code = RZG2L_CSI2_DEFAULT_FMT;
> +	fmt.format.colorspace = V4L2_COLORSPACE_SRGB;
> +	fmt.format.ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
> +	fmt.format.quantization = V4L2_QUANTIZATION_DEFAULT;
> +	fmt.format.xfer_func = V4L2_XFER_FUNC_DEFAULT;
> +
> +	return rzg2l_csi2_set_format(sd, sd_state, &fmt);
> +}
> +
> +static int rzg2l_csi2_enum_mbus_code(struct v4l2_subdev *sd,
> +				     struct v4l2_subdev_state *sd_state,
> +				     struct v4l2_subdev_mbus_code_enum *code)
> +{
> +	if (code->index >= ARRAY_SIZE(rzg2l_csi2_formats))
> +		return -EINVAL;
> +
> +	code->code = rzg2l_csi2_formats[code->index].code;
> +
> +	return 0;
> +}
> +
> +static int rzg2l_csi2_enum_frame_size(struct v4l2_subdev *sd,
> +				      struct v4l2_subdev_state *sd_state,
> +				      struct v4l2_subdev_frame_size_enum *fse)
> +{
> +	if (fse->index != 0)
> +		return -EINVAL;
> +
> +	fse->min_width = RZG2L_CSI2_MIN_WIDTH;
> +	fse->min_height = RZG2L_CSI2_MIN_HEIGHT;
> +	fse->max_width = RZG2L_CSI2_MAX_WIDTH;
> +	fse->max_height = RZG2L_CSI2_MAX_HEIGHT;
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_subdev_video_ops rzg2l_csi2_video_ops = {
> +	.s_stream = rzg2l_csi2_s_stream,
> +	.pre_streamon = rzg2l_csi2_pre_streamon,
> +	.post_streamoff = rzg2l_csi2_post_streamoff,
> +};
> +
> +static const struct v4l2_subdev_pad_ops rzg2l_csi2_pad_ops = {
> +	.enum_mbus_code = rzg2l_csi2_enum_mbus_code,
> +	.init_cfg = rzg2l_csi2_init_config,
> +	.enum_frame_size = rzg2l_csi2_enum_frame_size,
> +	.set_fmt = rzg2l_csi2_set_format,
> +	.get_fmt = v4l2_subdev_get_fmt,
> +};
> +
> +static const struct v4l2_subdev_ops rzg2l_csi2_subdev_ops = {
> +	.video	= &rzg2l_csi2_video_ops,
> +	.pad	= &rzg2l_csi2_pad_ops,
> +};
> +
> +/* -----------------------------------------------------------------------------
> + * Async handling and registration of subdevices and links.
> + */
> +
> +static int rzg2l_csi2_notify_bound(struct v4l2_async_notifier *notifier,
> +				   struct v4l2_subdev *subdev,
> +				   struct v4l2_async_subdev *asd)
> +{
> +	struct rzg2l_csi2 *csi2 = notifier_to_csi2(notifier);
> +
> +	csi2->remote_source = subdev;
> +
> +	dev_dbg(csi2->dev, "Bound subdev: %s pad\n", subdev->name);
> +
> +	return media_create_pad_link(&subdev->entity, RZG2L_CSI2_SINK,
> +				     &csi2->subdev.entity, 0,
> +				     MEDIA_LNK_FL_ENABLED |
> +				     MEDIA_LNK_FL_IMMUTABLE);
> +}
> +
> +static void rzg2l_csi2_notify_unbind(struct v4l2_async_notifier *notifier,
> +				     struct v4l2_subdev *subdev,
> +				     struct v4l2_async_subdev *asd)
> +{
> +	struct rzg2l_csi2 *csi2 = notifier_to_csi2(notifier);
> +
> +	csi2->remote_source = NULL;
> +
> +	dev_dbg(csi2->dev, "Unbind subdev %s\n", subdev->name);
> +}
> +
> +static const struct v4l2_async_notifier_operations rzg2l_csi2_notify_ops = {
> +	.bound = rzg2l_csi2_notify_bound,
> +	.unbind = rzg2l_csi2_notify_unbind,
> +};
> +
> +static int rzg2l_csi2_parse_v4l2(struct rzg2l_csi2 *csi2,
> +				 struct v4l2_fwnode_endpoint *vep)
> +{
> +	/* Only port 0 endpoint 0 is valid. */
> +	if (vep->base.port || vep->base.id)
> +		return -ENOTCONN;
> +
> +	csi2->lanes = vep->bus.mipi_csi2.num_data_lanes;
> +
> +	return 0;
> +}
> +
> +static int rzg2l_csi2_parse_dt(struct rzg2l_csi2 *csi2)
> +{
> +	struct v4l2_fwnode_endpoint v4l2_ep = {
> +		.bus_type = V4L2_MBUS_CSI2_DPHY
> +	};
> +	struct v4l2_async_subdev *asd;
> +	struct fwnode_handle *fwnode;
> +	struct fwnode_handle *ep;
> +	int ret;
> +
> +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(csi2->dev), 0, 0, 0);
> +	if (!ep) {
> +		dev_err(csi2->dev, "Not connected to subdevice\n");
> +		return -EINVAL;
> +	}
> +
> +	ret = v4l2_fwnode_endpoint_parse(ep, &v4l2_ep);
> +	if (ret) {
> +		dev_err(csi2->dev, "Could not parse v4l2 endpoint\n");
> +		fwnode_handle_put(ep);
> +		return -EINVAL;
> +	}
> +
> +	ret = rzg2l_csi2_parse_v4l2(csi2, &v4l2_ep);
> +	if (ret) {
> +		fwnode_handle_put(ep);
> +		return ret;
> +	}
> +
> +	fwnode = fwnode_graph_get_remote_endpoint(ep);
> +	fwnode_handle_put(ep);
> +
> +	v4l2_async_nf_init(&csi2->notifier);
> +	csi2->notifier.ops = &rzg2l_csi2_notify_ops;
> +
> +	asd = v4l2_async_nf_add_fwnode(&csi2->notifier, fwnode,
> +				       struct v4l2_async_subdev);
> +	fwnode_handle_put(fwnode);
> +	if (IS_ERR(asd))
> +		return PTR_ERR(asd);
> +
> +	ret = v4l2_async_subdev_nf_register(&csi2->subdev, &csi2->notifier);
> +	if (ret)
> +		v4l2_async_nf_cleanup(&csi2->notifier);
> +
> +	return ret;
> +}
> +
> +static int rzg2l_validate_csi2_lanes(struct rzg2l_csi2 *csi2)
> +{
> +	int ret = 0;
> +	int lanes;
> +
> +	if (csi2->lanes != 1 && csi2->lanes != 2 && csi2->lanes != 4) {
> +		dev_err(csi2->dev, "Unsupported number of data-lanes: %u\n",
> +			csi2->lanes);
> +		return -EINVAL;
> +	}
> +
> +	ret = rzg2l_csi2_enable_reg_access(csi2);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* Checking the maximum lanes support for CSI-2 module */
> +	lanes = (rzg2l_csi2_read(csi2, CSI2nMCG) & CSI2nMCG_SDLN) >> 8;
> +	if (lanes < csi2->lanes) {
> +		dev_err(csi2->dev,
> +			"Failed to support %d data lanes\n", csi2->lanes);
> +		ret = -EINVAL;
> +	}
> +
> +	rzg2l_csi2_disable_reg_access(csi2);
> +
> +	return ret;
> +}
> +
> +/* -----------------------------------------------------------------------------
> + * Platform Device Driver.
> + */
> +
> +static const struct media_entity_operations rzg2l_csi2_entity_ops = {
> +	.link_validate = v4l2_subdev_link_validate,
> +};
> +
> +static int rzg2l_csi2_probe(struct platform_device *pdev)
> +{
> +	struct rzg2l_csi2 *csi2;
> +	struct clk *vclk;
> +	int ret;
> +
> +	csi2 = devm_kzalloc(&pdev->dev, sizeof(*csi2), GFP_KERNEL);
> +	if (!csi2)
> +		return -ENOMEM;
> +
> +	csi2->base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(csi2->base))
> +		return PTR_ERR(csi2->base);
> +
> +	csi2->cmn_rstb = devm_reset_control_get_exclusive(&pdev->dev, "cmn-rstb");
> +	if (IS_ERR(csi2->cmn_rstb))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(csi2->cmn_rstb),
> +				     "Failed to get cpg cmn-rstb\n");
> +
> +	csi2->presetn = devm_reset_control_get_shared(&pdev->dev, "presetn");

Is this really a shared reset control, or do you use the shared API only
to enable reference counting of the reset controller ?

> +	if (IS_ERR(csi2->presetn))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(csi2->presetn),
> +				     "Failed to get cpg presetn\n");
> +
> +	csi2->sysclk = devm_clk_get(&pdev->dev, "system");
> +	if (IS_ERR(csi2->sysclk))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(csi2->sysclk),
> +				     "Failed to get system clk\n");
> +
> +	vclk = clk_get(&pdev->dev, "video");
> +	if (IS_ERR(vclk))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(vclk),
> +				     "Failed to get video clock\n");
> +	csi2->vclk_rate = clk_get_rate(vclk);
> +	clk_put(vclk);
> +
> +	csi2->dev = &pdev->dev;
> +
> +	platform_set_drvdata(pdev, csi2);
> +
> +	ret = rzg2l_csi2_parse_dt(csi2);
> +	if (ret)
> +		return ret;
> +
> +	pm_runtime_enable(&pdev->dev);
> +
> +	ret = rzg2l_validate_csi2_lanes(csi2);
> +	if (ret)
> +		goto error_pm;
> +
> +	csi2->subdev.dev = &pdev->dev;
> +	v4l2_subdev_init(&csi2->subdev, &rzg2l_csi2_subdev_ops);
> +	v4l2_set_subdevdata(&csi2->subdev, &pdev->dev);
> +	snprintf(csi2->subdev.name, sizeof(csi2->subdev.name),
> +		 "csi-%s", dev_name(&pdev->dev));
> +	csi2->subdev.flags = V4L2_SUBDEV_FL_HAS_DEVNODE;
> +
> +	csi2->subdev.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
> +	csi2->subdev.entity.ops = &rzg2l_csi2_entity_ops;
> +
> +	csi2->pads[RZG2L_CSI2_SINK].flags = MEDIA_PAD_FL_SINK;
> +	/*
> +	 * TODO: RZ/G2L CSI2 supports 4 virtual channels, as virtual
> +	 * channels should be implemented by streams API which is under
> +	 * development lets hardcode to VC0 for now.
> +	 */
> +	csi2->pads[RZG2L_CSI2_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
> +	ret = media_entity_pads_init(&csi2->subdev.entity, 2, csi2->pads);
> +	if (ret)
> +		goto error_pm;
> +
> +	ret = v4l2_subdev_init_finalize(&csi2->subdev);
> +	if (ret < 0)
> +		goto error_async;
> +
> +	ret = v4l2_async_register_subdev(&csi2->subdev);
> +	if (ret < 0)
> +		goto error_subdev;
> +
> +	return 0;
> +
> +error_subdev:
> +	v4l2_subdev_cleanup(&csi2->subdev);
> +error_async:
> +	v4l2_async_nf_unregister(&csi2->notifier);
> +	v4l2_async_nf_cleanup(&csi2->notifier);
> +	media_entity_cleanup(&csi2->subdev.entity);
> +error_pm:
> +	pm_runtime_disable(&pdev->dev);
> +
> +	return ret;
> +}
> +
> +static int rzg2l_csi2_remove(struct platform_device *pdev)
> +{
> +	struct rzg2l_csi2 *csi2 = platform_get_drvdata(pdev);
> +
> +	v4l2_async_nf_unregister(&csi2->notifier);
> +	v4l2_async_nf_cleanup(&csi2->notifier);
> +	v4l2_async_unregister_subdev(&csi2->subdev);
> +	v4l2_subdev_cleanup(&csi2->subdev);
> +	media_entity_cleanup(&csi2->subdev.entity);
> +	pm_runtime_disable(&pdev->dev);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id rzg2l_csi2_of_table[] = {
> +	{ .compatible = "renesas,rzg2l-csi2", },
> +	{ /* sentinel */ }
> +};
> +
> +static struct platform_driver rzg2l_csi2_pdrv = {
> +	.remove	= rzg2l_csi2_remove,
> +	.probe	= rzg2l_csi2_probe,
> +	.driver	= {
> +		.name = "rzg2l-csi2",
> +		.of_match_table = rzg2l_csi2_of_table,
> +	},
> +};
> +
> +module_platform_driver(rzg2l_csi2_pdrv);
> +
> +MODULE_AUTHOR("Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>");
> +MODULE_DESCRIPTION("Renesas RZ/G2L MIPI CSI2 receiver driver");
> +MODULE_LICENSE("GPL");
  
Lad, Prabhakar Nov. 22, 2022, 5:42 p.m. UTC | #2
Hi Laurent,

Thank you for the review.

On Tue, Nov 22, 2022 at 1:15 AM Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
>
> Hi Prabhakar,
>
> Thank you for the patch.
>
> On Wed, Nov 02, 2022 at 12:43:28AM +0000, Prabhakar wrote:
> > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> >
> > Add MIPI CSI-2 receiver driver for Renesas RZ/G2L. The MIPI
> > CSI-2 is part of the CRU module found on RZ/G2L family.
> >
> > Based on a patch in the BSP by Hien Huynh
> > <hien.huynh.px@renesas.com>
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > ---
> > v4 -> v5
> > * Made sure to cleanup in s_stream error path
> >
<snip>
> > +struct rzg2l_csi2_timings {
> > +     u32 t_init;
> > +     u32 tclk_miss;
> > +     u32 tclk_settle;
> > +     u32 ths_settle;
> > +     u32 tclk_prepare;
> > +     u32 ths_prepare;
> > +     u32 max_hsfreq;
> > +};
> > +
> > +static const struct rzg2l_csi2_timings rzg2l_csi2_global_timings[] = {
> > +     [0] = {
>
> You can drop [0]. Same below.
>
The ths_settle value differs for [1].

> > +             .max_hsfreq = 80,
> > +             .t_init = 79801,
> > +             .tclk_miss = 4,
> > +             .tclk_settle = 23,
> > +             .ths_settle = 31,
> > +             .tclk_prepare = 10,
> > +             .ths_prepare = 19,
> > +     },
> > +     [1] = {
> > +             .max_hsfreq = 125,
> > +             .t_init = 79801,
> > +             .tclk_miss = 4,
> > +             .tclk_settle = 23,
> > +             .ths_settle = 28,
> > +             .tclk_prepare = 10,
> > +             .ths_prepare = 19,
> > +     },
> > +     [2] = {
> > +             .max_hsfreq = 250,
> > +             .t_init = 79801,
> > +             .tclk_miss = 4,
> > +             .tclk_settle = 23,
> > +             .ths_settle = 22,
> > +             .tclk_prepare = 10,
> > +             .ths_prepare = 16,
> > +     },
> > +     [3] = {
> > +             .max_hsfreq = 360,
> > +             .t_init = 79801,
> > +             .tclk_miss = 4,
> > +             .tclk_settle = 18,
> > +             .ths_settle = 19,
> > +             .tclk_prepare = 10,
> > +             .ths_prepare = 10,
> > +     },
> > +     [4] = {
> > +             .max_hsfreq = 1500,
> > +             .t_init = 79801,
> > +             .tclk_miss = 4,
> > +             .tclk_settle = 18,
> > +             .ths_settle = 18,
> > +             .tclk_prepare = 10,
> > +             .ths_prepare = 10,
> > +     },
> > +};
> > +
> > +struct rzg2l_csi2_format {
> > +     u32 code;
> > +     unsigned int datatype;
> > +     unsigned int bpp;
> > +};
> > +
> > +static const struct rzg2l_csi2_format rzg2l_csi2_formats[] = {
> > +     { .code = MEDIA_BUS_FMT_UYVY8_1X16,     .datatype = 0x1e, .bpp = 16 },
> > +};
> > +
> > +static inline struct rzg2l_csi2 *sd_to_csi2(struct v4l2_subdev *sd)
> > +{
> > +     return container_of(sd, struct rzg2l_csi2, subdev);
> > +}
> > +
> > +static const struct rzg2l_csi2_format *rzg2l_csi2_code_to_fmt(unsigned int code)
> > +{
> > +     unsigned int i;
> > +
> > +     for (i = 0; i < ARRAY_SIZE(rzg2l_csi2_formats); i++)
> > +             if (rzg2l_csi2_formats[i].code == code)
> > +                     return &rzg2l_csi2_formats[i];
> > +
> > +     return NULL;
> > +}
> > +
> > +static inline struct rzg2l_csi2 *notifier_to_csi2(struct v4l2_async_notifier *n)
> > +{
> > +     return container_of(n, struct rzg2l_csi2, notifier);
> > +}
> > +
> > +static u32 rzg2l_csi2_read(struct rzg2l_csi2 *csi2, unsigned int reg)
> > +{
> > +     return ioread32(csi2->base + reg);
> > +}
> > +
> > +static void rzg2l_csi2_write(struct rzg2l_csi2 *csi2, unsigned int reg,
> > +                          u32 data)
> > +{
> > +     iowrite32(data, csi2->base + reg);
> > +}
> > +
> > +static void rzg2l_csi2_set(struct rzg2l_csi2 *csi2, unsigned int reg, u32 set)
> > +{
> > +     rzg2l_csi2_write(csi2, reg, rzg2l_csi2_read(csi2, reg) | set);
> > +}
> > +
> > +static void rzg2l_csi2_clr(struct rzg2l_csi2 *csi2, unsigned int reg, u32 clr)
> > +{
> > +     rzg2l_csi2_write(csi2, reg, rzg2l_csi2_read(csi2, reg) & ~clr);
> > +}
> > +
> > +static int rzg2l_csi2_calc_mbps(struct rzg2l_csi2 *csi2)
> > +{
> > +     struct v4l2_subdev *source = csi2->remote_source;
> > +     const struct rzg2l_csi2_format *format;
> > +     const struct v4l2_mbus_framefmt *fmt;
> > +     struct v4l2_subdev_state *state;
> > +     struct v4l2_ctrl *ctrl;
> > +     u64 mbps;
> > +
> > +     /* Read the pixel rate control from remote. */
> > +     ctrl = v4l2_ctrl_find(source->ctrl_handler, V4L2_CID_PIXEL_RATE);
> > +     if (!ctrl) {
> > +             dev_err(csi2->dev, "no pixel rate control in subdev %s\n",
> > +                     source->name);
> > +             return -EINVAL;
> > +     }
> > +
> > +     state = v4l2_subdev_lock_and_get_active_state(&csi2->subdev);
> > +     fmt = v4l2_subdev_get_pad_format(&csi2->subdev, state, RZG2L_CSI2_SINK);
> > +     format = rzg2l_csi2_code_to_fmt(fmt->code);
> > +     v4l2_subdev_unlock_state(state);
> > +
> > +     /*
> > +      * Calculate hsfreq in Mbps
> > +      * hsfreq = (pixel_rate * bits_per_sample) / number_of_lanes
> > +      */
> > +     mbps = v4l2_ctrl_g_ctrl_int64(ctrl) * format->bpp;
> > +     do_div(mbps, csi2->lanes * 1000000);
> > +
> > +     return mbps;
> > +}
> > +
> > +/* -----------------------------------------------------------------------------
> > + * DPHY setting
> > + */
> > +
> > +static int rzg2l_csi2_dphy_disable(struct rzg2l_csi2 *csi2)
> > +{
> > +     int ret;
> > +
> > +     /* Reset the CRU (D-PHY) */
> > +     ret = reset_control_assert(csi2->cmn_rstb);
> > +     if (ret)
> > +             return ret;
> > +
> > +     /* Stop the D-PHY clock */
> > +     clk_disable_unprepare(csi2->sysclk);
> > +
> > +     /* Cancel the EN_LDO1200 register setting */
> > +     rzg2l_csi2_clr(csi2, CSIDPHYCTRL0, CSIDPHYCTRL0_EN_LDO1200);
> > +
> > +     /* Cancel the EN_BGR register setting */
> > +     rzg2l_csi2_clr(csi2, CSIDPHYCTRL0, CSIDPHYCTRL0_EN_BGR);
> > +
> > +     csi2->dphy_enabled = false;
> > +
> > +     return 0;
> > +}
> > +
> > +static int rzg2l_csi2_dphy_enable(struct rzg2l_csi2 *csi2)
> > +{
> > +     const struct rzg2l_csi2_timings *dphy_timing;
> > +     u32 dphytim0, dphytim1;
> > +     unsigned int i;
> > +     int mbps;
> > +     int ret;
> > +
> > +     mbps = rzg2l_csi2_calc_mbps(csi2);
> > +     if (mbps < 0)
> > +             return mbps;
> > +
> > +     csi2->hsfreq = mbps;
> > +
> > +     /* Set DPHY timing parameters */
> > +     for (i = 0; i < ARRAY_SIZE(rzg2l_csi2_global_timings); ++i) {
> > +             dphy_timing = &rzg2l_csi2_global_timings[i];
> > +
> > +             if (csi2->hsfreq <= dphy_timing->max_hsfreq)
> > +                     break;
> > +     }
> > +
> > +     if (i >= ARRAY_SIZE(rzg2l_csi2_global_timings))
> > +             return -EINVAL;
> > +
> > +     /* Set D-PHY timing parameters */
> > +     dphytim0 = CSIDPHYTIM0_TCLK_MISS(dphy_timing->tclk_miss) |
> > +                     CSIDPHYTIM0_T_INIT(dphy_timing->t_init);
> > +     dphytim1 = CSIDPHYTIM1_THS_PREPARE(dphy_timing->ths_prepare) |
> > +                     CSIDPHYTIM1_TCLK_PREPARE(dphy_timing->tclk_prepare) |
> > +                     CSIDPHYTIM1_THS_SETTLE(dphy_timing->ths_settle) |
> > +                     CSIDPHYTIM1_TCLK_SETTLE(dphy_timing->tclk_settle);
> > +     rzg2l_csi2_write(csi2, CSIDPHYTIM0, dphytim0);
> > +     rzg2l_csi2_write(csi2, CSIDPHYTIM1, dphytim1);
> > +
> > +     /* Enable D-PHY power control 0 */
> > +     rzg2l_csi2_write(csi2, CSIDPHYSKW0, CSIDPHYSKW0_DEFAULT_SKW);
> > +
> > +     /* Set the EN_BGR bit */
> > +     rzg2l_csi2_set(csi2, CSIDPHYCTRL0, CSIDPHYCTRL0_EN_BGR);
> > +
> > +     /* Delay 20us to be stable */
> > +     usleep_range(20, 40);
> > +
> > +     /* Enable D-PHY power control 1 */
> > +     rzg2l_csi2_set(csi2, CSIDPHYCTRL0, CSIDPHYCTRL0_EN_LDO1200);
> > +
> > +     /* Delay 10us to be stable */
> > +     usleep_range(10, 20);
> > +
> > +     /* Start supplying the internal clock for the D-PHY block */
> > +     ret = clk_prepare_enable(csi2->sysclk);
> > +     if (ret)
> > +             rzg2l_csi2_dphy_disable(csi2);
> > +
> > +     csi2->dphy_enabled = true;
> > +
> > +     return ret;
> > +}
> > +
> > +static int rzg2l_csi2_enable_reg_access(struct rzg2l_csi2 *csi2)
> > +{
> > +     int ret;
> > +
> > +     ret = reset_control_deassert(csi2->presetn);
> > +     if (ret < 0)
> > +             return ret;
>
> Could this be done in the runtime PM resume handler ? Same for
> reset_control_assert() in the runtime PM suspend handler.
>
Yes it can be done, I'll move them to the runtime PM handlers.

> > +
> > +     ret = pm_runtime_resume_and_get(csi2->dev);
> > +     if (ret)
> > +             reset_control_assert(csi2->presetn);
> > +
> > +     return ret;
> > +}
> > +
> > +static void rzg2l_csi2_disable_reg_access(struct rzg2l_csi2 *csi2)
> > +{
> > +     pm_runtime_put_sync(csi2->dev);
> > +     reset_control_assert(csi2->presetn);
> > +}
> > +
> > +static int rzg2l_csi2_dphy_setting(struct v4l2_subdev *sd, bool on)
> > +{
> > +     struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
> > +     int ret;
> > +
> > +     ret = rzg2l_csi2_enable_reg_access(csi2);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     if (on)
> > +             ret = rzg2l_csi2_dphy_enable(csi2);
> > +     else
> > +             ret = rzg2l_csi2_dphy_disable(csi2);
> > +
> > +     rzg2l_csi2_disable_reg_access(csi2);
> > +
> > +     return ret;
> > +}
> > +
> > +static void rzg2l_csi2_mipi_link_enable(struct rzg2l_csi2 *csi2)
> > +{
> > +     unsigned long vclk_rate = csi2->vclk_rate / HZ_PER_MHZ;
> > +     u32 frrskw, frrclk, frrskw_coeff, frrclk_coeff;
> > +
> > +     /* Select data lanes */
> > +     rzg2l_csi2_write(csi2, CSI2nMCT0, CSI2nMCT0_VDLN(csi2->lanes));
> > +
> > +     frrskw_coeff = 3 * vclk_rate * 8;
> > +     frrclk_coeff = frrskw_coeff / 2;
> > +     frrskw = DIV_ROUND_UP(frrskw_coeff, csi2->hsfreq);
> > +     frrclk = DIV_ROUND_UP(frrclk_coeff, csi2->hsfreq);
> > +     rzg2l_csi2_write(csi2, CSI2nMCT2, CSI2nMCT2_FRRSKW(frrskw) |
> > +                      CSI2nMCT2_FRRCLK(frrclk));
> > +
> > +     /*
> > +      * Select data type.
> > +      * FS, FE, LS, LE, Generic Short Packet Codes 1 to 8,
> > +      * Generic Long Packet Data Types 1 to 4 YUV422 8-bit,
> > +      * RGB565, RGB888, RAW8 to RAW20, User-defined 8-bit
> > +      * data types 1 to 8
> > +      */
> > +     rzg2l_csi2_write(csi2, CSI2nDTEL, 0xf778ff0f);
> > +     rzg2l_csi2_write(csi2, CSI2nDTEH, 0x00ffff1f);
> > +
> > +     /* Enable LINK reception */
> > +     rzg2l_csi2_write(csi2, CSI2nMCT3, CSI2nMCT3_RXEN);
> > +}
> > +
> > +static void rzg2l_csi2_mipi_link_disable(struct rzg2l_csi2 *csi2)
> > +{
> > +     unsigned int timeout = VSRSTS_RETRIES;
> > +
> > +     /* Stop LINK reception */
> > +     rzg2l_csi2_clr(csi2, CSI2nMCT3, CSI2nMCT3_RXEN);
> > +
> > +     /* Request a software reset of the LINK Video Pixel Interface */
> > +     rzg2l_csi2_write(csi2, CSI2nRTCT, CSI2nRTCT_VSRST);
> > +
> > +     /* Make sure CSI2nRTST.VSRSTS bit is cleared */
> > +     while (timeout--) {
> > +             if (!(rzg2l_csi2_read(csi2, CSI2nRTST) & CSI2nRTST_VSRSTS))
> > +                     break;
> > +             usleep_range(100, 200);
> > +     };
> > +
> > +     if (!timeout)
> > +             dev_err(csi2->dev, "Clearing CSI2nRTST.VSRSTS timed out\n");
> > +}
> > +
> > +static int rzg2l_csi2_mipi_link_setting(struct v4l2_subdev *sd, bool on)
> > +{
> > +     struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
> > +     int ret;
> > +
> > +     ret = rzg2l_csi2_enable_reg_access(csi2);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     if (on)
> > +             rzg2l_csi2_mipi_link_enable(csi2);
> > +     else
> > +             rzg2l_csi2_mipi_link_disable(csi2);
> > +
> > +     rzg2l_csi2_disable_reg_access(csi2);
>
> This doesn't seem right. Runtime PM isn't just about register access.
> You need to call pm_runtime_resume_and_get() at the beginning of
> rzg2l_csi2_s_stream() when enabling, and pm_runtime_put_sync() at the
> end of rzg2l_csi2_s_stream() when disabling (+ error paths for the
> enable case).
>
OK, I'll make use of runtime PM in s_stream callback.

> > +
> > +     return 0;
> > +}
> > +
> > +static int rzg2l_csi2_s_stream(struct v4l2_subdev *sd, int enable)
> > +{
> > +     struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
> > +     int s_stream_ret = 0;
> > +     int ret;
> > +
> > +     if (enable) {
> > +             int ret;
> > +
> > +             ret = rzg2l_csi2_mipi_link_setting(sd, 1);
> > +             if (ret)
> > +                     return ret;
> > +
> > +             ret = reset_control_deassert(csi2->cmn_rstb);
> > +             if (ret)
> > +                     goto err_mipi_link_disable;
> > +     }
> > +
> > +     ret = v4l2_subdev_call(csi2->remote_source, video, s_stream, enable);
> > +     if (ret) {
> > +             s_stream_ret = ret;
> > +             dev_err(csi2->dev, "s_stream failed on remote source\n");
>
> With
> https://lore.kernel.org/linux-media/20221026065123.595777-1-sakari.ailus@linux.intel.com/
> I think you can drop this error message.
>
Agreed, I will drop the error message.

> > +     }
> > +
> > +     if (enable && ret)
> > +             goto err_assert_rstb;
> > +
> > +     if (!enable) {
> > +             ret = rzg2l_csi2_dphy_setting(sd, 0);
> > +             if (ret && !s_stream_ret)
> > +                     s_stream_ret = ret;
> > +             ret = rzg2l_csi2_mipi_link_setting(sd, 0);
> > +             if (ret && !s_stream_ret)
> > +                     s_stream_ret = ret;
> > +     }
> > +
> > +     return s_stream_ret;
> > +
> > +err_assert_rstb:
> > +     reset_control_assert(csi2->cmn_rstb);
> > +err_mipi_link_disable:
> > +     rzg2l_csi2_mipi_link_setting(sd, 0);
> > +     return ret;
> > +}
> > +
> > +static int rzg2l_csi2_pre_streamon(struct v4l2_subdev *sd, u32 flags)
> > +{
> > +     return rzg2l_csi2_dphy_setting(sd, 1);
> > +}
> > +
> > +static int rzg2l_csi2_post_streamoff(struct v4l2_subdev *sd)
> > +{
> > +     struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
> > +
> > +     /*
> > +      * In ideal case D-PHY will be disabled in s_stream(0) callback
> > +      * as mentioned the HW manual. The below will only happen when
> > +      * pre_streamon succeeds and further down the line s_stream(1)
> > +      * fails so we need to undo things in post_streamoff.
> > +      */
> > +     if (csi2->dphy_enabled)
> > +             return rzg2l_csi2_dphy_setting(sd, 0);
> > +
> > +     return 0;
> > +}
> > +
> > +static int rzg2l_csi2_set_format(struct v4l2_subdev *sd,
> > +                              struct v4l2_subdev_state *state,
> > +                              struct v4l2_subdev_format *fmt)
> > +{
> > +     struct v4l2_mbus_framefmt *src_format;
> > +     struct v4l2_mbus_framefmt *sink_format;
> > +
> > +     if (fmt->pad != RZG2L_CSI2_SINK && fmt->pad != RZG2L_CSI2_SOURCE)
> > +             return -EINVAL;
>
> You can drop this check as the set_format wrapper validates the pad
> value already.
>
OK, I will drop this check.

> > +
> > +     sink_format = v4l2_subdev_get_pad_format(sd, state, RZG2L_CSI2_SINK);
> > +     src_format = v4l2_subdev_get_pad_format(sd, state, RZG2L_CSI2_SOURCE);
>
> As the CSI-2 receiver can't modify the format on the output,
> set_format() on the source pad must not modify the format. Just add
>
>         if (fmt->pad == RZG2L_CSI2_SOURCE) {
>                 fmt->format = *src_format;
>                 return 0;
>         }
>
> here.
>
OK, I will update as above.

> > +
> > +     if (!rzg2l_csi2_code_to_fmt(fmt->format.code))
> > +             sink_format->code = rzg2l_csi2_formats[0].code;
> > +     else
> > +             sink_format->code = fmt->format.code;
> > +
> > +     sink_format->field = V4L2_FIELD_NONE;
> > +     sink_format->colorspace = fmt->format.colorspace;
> > +     sink_format->xfer_func = fmt->format.xfer_func;
> > +     sink_format->ycbcr_enc = fmt->format.ycbcr_enc;
> > +     sink_format->quantization = fmt->format.quantization;
> > +     sink_format->width = clamp_t(u32, fmt->format.width,
> > +                                  RZG2L_CSI2_MIN_WIDTH, RZG2L_CSI2_MAX_WIDTH);
> > +     sink_format->height = clamp_t(u32, fmt->format.height,
> > +                                   RZG2L_CSI2_MIN_HEIGHT, RZG2L_CSI2_MAX_HEIGHT);
> > +     fmt->format = *sink_format;
> > +
> > +     /* propagate format to source pad */
> > +     *src_format = *sink_format;
> > +
> > +     return 0;
> > +}
> > +
> > +static int rzg2l_csi2_init_config(struct v4l2_subdev *sd,
> > +                               struct v4l2_subdev_state *sd_state)
> > +{
> > +     struct v4l2_subdev_format fmt = { .pad = RZG2L_CSI2_SINK, };
> > +
> > +     fmt.format.width = RZG2L_CSI2_DEFAULT_WIDTH;
> > +     fmt.format.height = RZG2L_CSI2_DEFAULT_HEIGHT;
> > +     fmt.format.field = V4L2_FIELD_NONE;
> > +     fmt.format.code = RZG2L_CSI2_DEFAULT_FMT;
> > +     fmt.format.colorspace = V4L2_COLORSPACE_SRGB;
> > +     fmt.format.ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
> > +     fmt.format.quantization = V4L2_QUANTIZATION_DEFAULT;
> > +     fmt.format.xfer_func = V4L2_XFER_FUNC_DEFAULT;
> > +
> > +     return rzg2l_csi2_set_format(sd, sd_state, &fmt);
> > +}
> > +
> > +static int rzg2l_csi2_enum_mbus_code(struct v4l2_subdev *sd,
> > +                                  struct v4l2_subdev_state *sd_state,
> > +                                  struct v4l2_subdev_mbus_code_enum *code)
> > +{
> > +     if (code->index >= ARRAY_SIZE(rzg2l_csi2_formats))
> > +             return -EINVAL;
> > +
> > +     code->code = rzg2l_csi2_formats[code->index].code;
> > +
> > +     return 0;
> > +}
> > +
> > +static int rzg2l_csi2_enum_frame_size(struct v4l2_subdev *sd,
> > +                                   struct v4l2_subdev_state *sd_state,
> > +                                   struct v4l2_subdev_frame_size_enum *fse)
> > +{
> > +     if (fse->index != 0)
> > +             return -EINVAL;
> > +
> > +     fse->min_width = RZG2L_CSI2_MIN_WIDTH;
> > +     fse->min_height = RZG2L_CSI2_MIN_HEIGHT;
> > +     fse->max_width = RZG2L_CSI2_MAX_WIDTH;
> > +     fse->max_height = RZG2L_CSI2_MAX_HEIGHT;
> > +
> > +     return 0;
> > +}
> > +
> > +static const struct v4l2_subdev_video_ops rzg2l_csi2_video_ops = {
> > +     .s_stream = rzg2l_csi2_s_stream,
> > +     .pre_streamon = rzg2l_csi2_pre_streamon,
> > +     .post_streamoff = rzg2l_csi2_post_streamoff,
> > +};
> > +
> > +static const struct v4l2_subdev_pad_ops rzg2l_csi2_pad_ops = {
> > +     .enum_mbus_code = rzg2l_csi2_enum_mbus_code,
> > +     .init_cfg = rzg2l_csi2_init_config,
> > +     .enum_frame_size = rzg2l_csi2_enum_frame_size,
> > +     .set_fmt = rzg2l_csi2_set_format,
> > +     .get_fmt = v4l2_subdev_get_fmt,
> > +};
> > +
> > +static const struct v4l2_subdev_ops rzg2l_csi2_subdev_ops = {
> > +     .video  = &rzg2l_csi2_video_ops,
> > +     .pad    = &rzg2l_csi2_pad_ops,
> > +};
> > +
> > +/* -----------------------------------------------------------------------------
> > + * Async handling and registration of subdevices and links.
> > + */
> > +
> > +static int rzg2l_csi2_notify_bound(struct v4l2_async_notifier *notifier,
> > +                                struct v4l2_subdev *subdev,
> > +                                struct v4l2_async_subdev *asd)
> > +{
> > +     struct rzg2l_csi2 *csi2 = notifier_to_csi2(notifier);
> > +
> > +     csi2->remote_source = subdev;
> > +
> > +     dev_dbg(csi2->dev, "Bound subdev: %s pad\n", subdev->name);
> > +
> > +     return media_create_pad_link(&subdev->entity, RZG2L_CSI2_SINK,
> > +                                  &csi2->subdev.entity, 0,
> > +                                  MEDIA_LNK_FL_ENABLED |
> > +                                  MEDIA_LNK_FL_IMMUTABLE);
> > +}
> > +
> > +static void rzg2l_csi2_notify_unbind(struct v4l2_async_notifier *notifier,
> > +                                  struct v4l2_subdev *subdev,
> > +                                  struct v4l2_async_subdev *asd)
> > +{
> > +     struct rzg2l_csi2 *csi2 = notifier_to_csi2(notifier);
> > +
> > +     csi2->remote_source = NULL;
> > +
> > +     dev_dbg(csi2->dev, "Unbind subdev %s\n", subdev->name);
> > +}
> > +
> > +static const struct v4l2_async_notifier_operations rzg2l_csi2_notify_ops = {
> > +     .bound = rzg2l_csi2_notify_bound,
> > +     .unbind = rzg2l_csi2_notify_unbind,
> > +};
> > +
> > +static int rzg2l_csi2_parse_v4l2(struct rzg2l_csi2 *csi2,
> > +                              struct v4l2_fwnode_endpoint *vep)
> > +{
> > +     /* Only port 0 endpoint 0 is valid. */
> > +     if (vep->base.port || vep->base.id)
> > +             return -ENOTCONN;
> > +
> > +     csi2->lanes = vep->bus.mipi_csi2.num_data_lanes;
> > +
> > +     return 0;
> > +}
> > +
> > +static int rzg2l_csi2_parse_dt(struct rzg2l_csi2 *csi2)
> > +{
> > +     struct v4l2_fwnode_endpoint v4l2_ep = {
> > +             .bus_type = V4L2_MBUS_CSI2_DPHY
> > +     };
> > +     struct v4l2_async_subdev *asd;
> > +     struct fwnode_handle *fwnode;
> > +     struct fwnode_handle *ep;
> > +     int ret;
> > +
> > +     ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(csi2->dev), 0, 0, 0);
> > +     if (!ep) {
> > +             dev_err(csi2->dev, "Not connected to subdevice\n");
> > +             return -EINVAL;
> > +     }
> > +
> > +     ret = v4l2_fwnode_endpoint_parse(ep, &v4l2_ep);
> > +     if (ret) {
> > +             dev_err(csi2->dev, "Could not parse v4l2 endpoint\n");
> > +             fwnode_handle_put(ep);
> > +             return -EINVAL;
> > +     }
> > +
> > +     ret = rzg2l_csi2_parse_v4l2(csi2, &v4l2_ep);
> > +     if (ret) {
> > +             fwnode_handle_put(ep);
> > +             return ret;
> > +     }
> > +
> > +     fwnode = fwnode_graph_get_remote_endpoint(ep);
> > +     fwnode_handle_put(ep);
> > +
> > +     v4l2_async_nf_init(&csi2->notifier);
> > +     csi2->notifier.ops = &rzg2l_csi2_notify_ops;
> > +
> > +     asd = v4l2_async_nf_add_fwnode(&csi2->notifier, fwnode,
> > +                                    struct v4l2_async_subdev);
> > +     fwnode_handle_put(fwnode);
> > +     if (IS_ERR(asd))
> > +             return PTR_ERR(asd);
> > +
> > +     ret = v4l2_async_subdev_nf_register(&csi2->subdev, &csi2->notifier);
> > +     if (ret)
> > +             v4l2_async_nf_cleanup(&csi2->notifier);
> > +
> > +     return ret;
> > +}
> > +
> > +static int rzg2l_validate_csi2_lanes(struct rzg2l_csi2 *csi2)
> > +{
> > +     int ret = 0;
> > +     int lanes;
> > +
> > +     if (csi2->lanes != 1 && csi2->lanes != 2 && csi2->lanes != 4) {
> > +             dev_err(csi2->dev, "Unsupported number of data-lanes: %u\n",
> > +                     csi2->lanes);
> > +             return -EINVAL;
> > +     }
> > +
> > +     ret = rzg2l_csi2_enable_reg_access(csi2);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     /* Checking the maximum lanes support for CSI-2 module */
> > +     lanes = (rzg2l_csi2_read(csi2, CSI2nMCG) & CSI2nMCG_SDLN) >> 8;
> > +     if (lanes < csi2->lanes) {
> > +             dev_err(csi2->dev,
> > +                     "Failed to support %d data lanes\n", csi2->lanes);
> > +             ret = -EINVAL;
> > +     }
> > +
> > +     rzg2l_csi2_disable_reg_access(csi2);
> > +
> > +     return ret;
> > +}
> > +
> > +/* -----------------------------------------------------------------------------
> > + * Platform Device Driver.
> > + */
> > +
> > +static const struct media_entity_operations rzg2l_csi2_entity_ops = {
> > +     .link_validate = v4l2_subdev_link_validate,
> > +};
> > +
> > +static int rzg2l_csi2_probe(struct platform_device *pdev)
> > +{
> > +     struct rzg2l_csi2 *csi2;
> > +     struct clk *vclk;
> > +     int ret;
> > +
> > +     csi2 = devm_kzalloc(&pdev->dev, sizeof(*csi2), GFP_KERNEL);
> > +     if (!csi2)
> > +             return -ENOMEM;
> > +
> > +     csi2->base = devm_platform_ioremap_resource(pdev, 0);
> > +     if (IS_ERR(csi2->base))
> > +             return PTR_ERR(csi2->base);
> > +
> > +     csi2->cmn_rstb = devm_reset_control_get_exclusive(&pdev->dev, "cmn-rstb");
> > +     if (IS_ERR(csi2->cmn_rstb))
> > +             return dev_err_probe(&pdev->dev, PTR_ERR(csi2->cmn_rstb),
> > +                                  "Failed to get cpg cmn-rstb\n");
> > +
> > +     csi2->presetn = devm_reset_control_get_shared(&pdev->dev, "presetn");
>
> Is this really a shared reset control, or do you use the shared API only
> to enable reference counting of the reset controller ?
>
As the CSI2 block is part of CRU itself the presetn reset (enables reg
access) is shared with the CRU driver too hence the use of shared api.

Cheers,
Prabhakar
  
Laurent Pinchart Nov. 22, 2022, 6:40 p.m. UTC | #3
Hi Prabhakar,

On Tue, Nov 22, 2022 at 05:42:46PM +0000, Lad, Prabhakar wrote:
> On Tue, Nov 22, 2022 at 1:15 AM Laurent Pinchart wrote:
> > On Wed, Nov 02, 2022 at 12:43:28AM +0000, Prabhakar wrote:
> > > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > >
> > > Add MIPI CSI-2 receiver driver for Renesas RZ/G2L. The MIPI
> > > CSI-2 is part of the CRU module found on RZ/G2L family.
> > >
> > > Based on a patch in the BSP by Hien Huynh
> > > <hien.huynh.px@renesas.com>
> > >
> > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > > ---
> > > v4 -> v5
> > > * Made sure to cleanup in s_stream error path
> > >
> <snip>
> > > +struct rzg2l_csi2_timings {
> > > +     u32 t_init;
> > > +     u32 tclk_miss;
> > > +     u32 tclk_settle;
> > > +     u32 ths_settle;
> > > +     u32 tclk_prepare;
> > > +     u32 ths_prepare;
> > > +     u32 max_hsfreq;
> > > +};
> > > +
> > > +static const struct rzg2l_csi2_timings rzg2l_csi2_global_timings[] = {
> > > +     [0] = {
> >
> > You can drop [0]. Same below.
> >
> The ths_settle value differs for [1].

I meant you can drop the "[0] = ", "[1] = ", ... :-)

> > > +             .max_hsfreq = 80,
> > > +             .t_init = 79801,
> > > +             .tclk_miss = 4,
> > > +             .tclk_settle = 23,
> > > +             .ths_settle = 31,
> > > +             .tclk_prepare = 10,
> > > +             .ths_prepare = 19,
> > > +     },
> > > +     [1] = {
> > > +             .max_hsfreq = 125,
> > > +             .t_init = 79801,
> > > +             .tclk_miss = 4,
> > > +             .tclk_settle = 23,
> > > +             .ths_settle = 28,
> > > +             .tclk_prepare = 10,
> > > +             .ths_prepare = 19,
> > > +     },
> > > +     [2] = {
> > > +             .max_hsfreq = 250,
> > > +             .t_init = 79801,
> > > +             .tclk_miss = 4,
> > > +             .tclk_settle = 23,
> > > +             .ths_settle = 22,
> > > +             .tclk_prepare = 10,
> > > +             .ths_prepare = 16,
> > > +     },
> > > +     [3] = {
> > > +             .max_hsfreq = 360,
> > > +             .t_init = 79801,
> > > +             .tclk_miss = 4,
> > > +             .tclk_settle = 18,
> > > +             .ths_settle = 19,
> > > +             .tclk_prepare = 10,
> > > +             .ths_prepare = 10,
> > > +     },
> > > +     [4] = {
> > > +             .max_hsfreq = 1500,
> > > +             .t_init = 79801,
> > > +             .tclk_miss = 4,
> > > +             .tclk_settle = 18,
> > > +             .ths_settle = 18,
> > > +             .tclk_prepare = 10,
> > > +             .ths_prepare = 10,
> > > +     },
> > > +};
> > > +
> > > +struct rzg2l_csi2_format {
> > > +     u32 code;
> > > +     unsigned int datatype;
> > > +     unsigned int bpp;
> > > +};
> > > +
> > > +static const struct rzg2l_csi2_format rzg2l_csi2_formats[] = {
> > > +     { .code = MEDIA_BUS_FMT_UYVY8_1X16,     .datatype = 0x1e, .bpp = 16 },
> > > +};
> > > +
> > > +static inline struct rzg2l_csi2 *sd_to_csi2(struct v4l2_subdev *sd)
> > > +{
> > > +     return container_of(sd, struct rzg2l_csi2, subdev);
> > > +}
> > > +
> > > +static const struct rzg2l_csi2_format *rzg2l_csi2_code_to_fmt(unsigned int code)
> > > +{
> > > +     unsigned int i;
> > > +
> > > +     for (i = 0; i < ARRAY_SIZE(rzg2l_csi2_formats); i++)
> > > +             if (rzg2l_csi2_formats[i].code == code)
> > > +                     return &rzg2l_csi2_formats[i];
> > > +
> > > +     return NULL;
> > > +}
> > > +
> > > +static inline struct rzg2l_csi2 *notifier_to_csi2(struct v4l2_async_notifier *n)
> > > +{
> > > +     return container_of(n, struct rzg2l_csi2, notifier);
> > > +}
> > > +
> > > +static u32 rzg2l_csi2_read(struct rzg2l_csi2 *csi2, unsigned int reg)
> > > +{
> > > +     return ioread32(csi2->base + reg);
> > > +}
> > > +
> > > +static void rzg2l_csi2_write(struct rzg2l_csi2 *csi2, unsigned int reg,
> > > +                          u32 data)
> > > +{
> > > +     iowrite32(data, csi2->base + reg);
> > > +}
> > > +
> > > +static void rzg2l_csi2_set(struct rzg2l_csi2 *csi2, unsigned int reg, u32 set)
> > > +{
> > > +     rzg2l_csi2_write(csi2, reg, rzg2l_csi2_read(csi2, reg) | set);
> > > +}
> > > +
> > > +static void rzg2l_csi2_clr(struct rzg2l_csi2 *csi2, unsigned int reg, u32 clr)
> > > +{
> > > +     rzg2l_csi2_write(csi2, reg, rzg2l_csi2_read(csi2, reg) & ~clr);
> > > +}
> > > +
> > > +static int rzg2l_csi2_calc_mbps(struct rzg2l_csi2 *csi2)
> > > +{
> > > +     struct v4l2_subdev *source = csi2->remote_source;
> > > +     const struct rzg2l_csi2_format *format;
> > > +     const struct v4l2_mbus_framefmt *fmt;
> > > +     struct v4l2_subdev_state *state;
> > > +     struct v4l2_ctrl *ctrl;
> > > +     u64 mbps;
> > > +
> > > +     /* Read the pixel rate control from remote. */
> > > +     ctrl = v4l2_ctrl_find(source->ctrl_handler, V4L2_CID_PIXEL_RATE);
> > > +     if (!ctrl) {
> > > +             dev_err(csi2->dev, "no pixel rate control in subdev %s\n",
> > > +                     source->name);
> > > +             return -EINVAL;
> > > +     }
> > > +
> > > +     state = v4l2_subdev_lock_and_get_active_state(&csi2->subdev);
> > > +     fmt = v4l2_subdev_get_pad_format(&csi2->subdev, state, RZG2L_CSI2_SINK);
> > > +     format = rzg2l_csi2_code_to_fmt(fmt->code);
> > > +     v4l2_subdev_unlock_state(state);
> > > +
> > > +     /*
> > > +      * Calculate hsfreq in Mbps
> > > +      * hsfreq = (pixel_rate * bits_per_sample) / number_of_lanes
> > > +      */
> > > +     mbps = v4l2_ctrl_g_ctrl_int64(ctrl) * format->bpp;
> > > +     do_div(mbps, csi2->lanes * 1000000);
> > > +
> > > +     return mbps;
> > > +}
> > > +
> > > +/* -----------------------------------------------------------------------------
> > > + * DPHY setting
> > > + */
> > > +
> > > +static int rzg2l_csi2_dphy_disable(struct rzg2l_csi2 *csi2)
> > > +{
> > > +     int ret;
> > > +
> > > +     /* Reset the CRU (D-PHY) */
> > > +     ret = reset_control_assert(csi2->cmn_rstb);
> > > +     if (ret)
> > > +             return ret;
> > > +
> > > +     /* Stop the D-PHY clock */
> > > +     clk_disable_unprepare(csi2->sysclk);
> > > +
> > > +     /* Cancel the EN_LDO1200 register setting */
> > > +     rzg2l_csi2_clr(csi2, CSIDPHYCTRL0, CSIDPHYCTRL0_EN_LDO1200);
> > > +
> > > +     /* Cancel the EN_BGR register setting */
> > > +     rzg2l_csi2_clr(csi2, CSIDPHYCTRL0, CSIDPHYCTRL0_EN_BGR);
> > > +
> > > +     csi2->dphy_enabled = false;
> > > +
> > > +     return 0;
> > > +}
> > > +
> > > +static int rzg2l_csi2_dphy_enable(struct rzg2l_csi2 *csi2)
> > > +{
> > > +     const struct rzg2l_csi2_timings *dphy_timing;
> > > +     u32 dphytim0, dphytim1;
> > > +     unsigned int i;
> > > +     int mbps;
> > > +     int ret;
> > > +
> > > +     mbps = rzg2l_csi2_calc_mbps(csi2);
> > > +     if (mbps < 0)
> > > +             return mbps;
> > > +
> > > +     csi2->hsfreq = mbps;
> > > +
> > > +     /* Set DPHY timing parameters */
> > > +     for (i = 0; i < ARRAY_SIZE(rzg2l_csi2_global_timings); ++i) {
> > > +             dphy_timing = &rzg2l_csi2_global_timings[i];
> > > +
> > > +             if (csi2->hsfreq <= dphy_timing->max_hsfreq)
> > > +                     break;
> > > +     }
> > > +
> > > +     if (i >= ARRAY_SIZE(rzg2l_csi2_global_timings))
> > > +             return -EINVAL;
> > > +
> > > +     /* Set D-PHY timing parameters */
> > > +     dphytim0 = CSIDPHYTIM0_TCLK_MISS(dphy_timing->tclk_miss) |
> > > +                     CSIDPHYTIM0_T_INIT(dphy_timing->t_init);
> > > +     dphytim1 = CSIDPHYTIM1_THS_PREPARE(dphy_timing->ths_prepare) |
> > > +                     CSIDPHYTIM1_TCLK_PREPARE(dphy_timing->tclk_prepare) |
> > > +                     CSIDPHYTIM1_THS_SETTLE(dphy_timing->ths_settle) |
> > > +                     CSIDPHYTIM1_TCLK_SETTLE(dphy_timing->tclk_settle);
> > > +     rzg2l_csi2_write(csi2, CSIDPHYTIM0, dphytim0);
> > > +     rzg2l_csi2_write(csi2, CSIDPHYTIM1, dphytim1);
> > > +
> > > +     /* Enable D-PHY power control 0 */
> > > +     rzg2l_csi2_write(csi2, CSIDPHYSKW0, CSIDPHYSKW0_DEFAULT_SKW);
> > > +
> > > +     /* Set the EN_BGR bit */
> > > +     rzg2l_csi2_set(csi2, CSIDPHYCTRL0, CSIDPHYCTRL0_EN_BGR);
> > > +
> > > +     /* Delay 20us to be stable */
> > > +     usleep_range(20, 40);
> > > +
> > > +     /* Enable D-PHY power control 1 */
> > > +     rzg2l_csi2_set(csi2, CSIDPHYCTRL0, CSIDPHYCTRL0_EN_LDO1200);
> > > +
> > > +     /* Delay 10us to be stable */
> > > +     usleep_range(10, 20);
> > > +
> > > +     /* Start supplying the internal clock for the D-PHY block */
> > > +     ret = clk_prepare_enable(csi2->sysclk);
> > > +     if (ret)
> > > +             rzg2l_csi2_dphy_disable(csi2);
> > > +
> > > +     csi2->dphy_enabled = true;
> > > +
> > > +     return ret;
> > > +}
> > > +
> > > +static int rzg2l_csi2_enable_reg_access(struct rzg2l_csi2 *csi2)
> > > +{
> > > +     int ret;
> > > +
> > > +     ret = reset_control_deassert(csi2->presetn);
> > > +     if (ret < 0)
> > > +             return ret;
> >
> > Could this be done in the runtime PM resume handler ? Same for
> > reset_control_assert() in the runtime PM suspend handler.
>
> Yes it can be done, I'll move them to the runtime PM handlers.

Great, that will make things easier :-) You could then drop the
enable|disable_reg_access wrappers and call the RPM functions directly.

> > > +
> > > +     ret = pm_runtime_resume_and_get(csi2->dev);
> > > +     if (ret)
> > > +             reset_control_assert(csi2->presetn);
> > > +
> > > +     return ret;
> > > +}
> > > +
> > > +static void rzg2l_csi2_disable_reg_access(struct rzg2l_csi2 *csi2)
> > > +{
> > > +     pm_runtime_put_sync(csi2->dev);
> > > +     reset_control_assert(csi2->presetn);
> > > +}
> > > +
> > > +static int rzg2l_csi2_dphy_setting(struct v4l2_subdev *sd, bool on)
> > > +{
> > > +     struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
> > > +     int ret;
> > > +
> > > +     ret = rzg2l_csi2_enable_reg_access(csi2);
> > > +     if (ret < 0)
> > > +             return ret;
> > > +
> > > +     if (on)
> > > +             ret = rzg2l_csi2_dphy_enable(csi2);
> > > +     else
> > > +             ret = rzg2l_csi2_dphy_disable(csi2);
> > > +
> > > +     rzg2l_csi2_disable_reg_access(csi2);
> > > +
> > > +     return ret;
> > > +}
> > > +
> > > +static void rzg2l_csi2_mipi_link_enable(struct rzg2l_csi2 *csi2)
> > > +{
> > > +     unsigned long vclk_rate = csi2->vclk_rate / HZ_PER_MHZ;
> > > +     u32 frrskw, frrclk, frrskw_coeff, frrclk_coeff;
> > > +
> > > +     /* Select data lanes */
> > > +     rzg2l_csi2_write(csi2, CSI2nMCT0, CSI2nMCT0_VDLN(csi2->lanes));
> > > +
> > > +     frrskw_coeff = 3 * vclk_rate * 8;
> > > +     frrclk_coeff = frrskw_coeff / 2;
> > > +     frrskw = DIV_ROUND_UP(frrskw_coeff, csi2->hsfreq);
> > > +     frrclk = DIV_ROUND_UP(frrclk_coeff, csi2->hsfreq);
> > > +     rzg2l_csi2_write(csi2, CSI2nMCT2, CSI2nMCT2_FRRSKW(frrskw) |
> > > +                      CSI2nMCT2_FRRCLK(frrclk));
> > > +
> > > +     /*
> > > +      * Select data type.
> > > +      * FS, FE, LS, LE, Generic Short Packet Codes 1 to 8,
> > > +      * Generic Long Packet Data Types 1 to 4 YUV422 8-bit,
> > > +      * RGB565, RGB888, RAW8 to RAW20, User-defined 8-bit
> > > +      * data types 1 to 8
> > > +      */
> > > +     rzg2l_csi2_write(csi2, CSI2nDTEL, 0xf778ff0f);
> > > +     rzg2l_csi2_write(csi2, CSI2nDTEH, 0x00ffff1f);
> > > +
> > > +     /* Enable LINK reception */
> > > +     rzg2l_csi2_write(csi2, CSI2nMCT3, CSI2nMCT3_RXEN);
> > > +}
> > > +
> > > +static void rzg2l_csi2_mipi_link_disable(struct rzg2l_csi2 *csi2)
> > > +{
> > > +     unsigned int timeout = VSRSTS_RETRIES;
> > > +
> > > +     /* Stop LINK reception */
> > > +     rzg2l_csi2_clr(csi2, CSI2nMCT3, CSI2nMCT3_RXEN);
> > > +
> > > +     /* Request a software reset of the LINK Video Pixel Interface */
> > > +     rzg2l_csi2_write(csi2, CSI2nRTCT, CSI2nRTCT_VSRST);
> > > +
> > > +     /* Make sure CSI2nRTST.VSRSTS bit is cleared */
> > > +     while (timeout--) {
> > > +             if (!(rzg2l_csi2_read(csi2, CSI2nRTST) & CSI2nRTST_VSRSTS))
> > > +                     break;
> > > +             usleep_range(100, 200);
> > > +     };
> > > +
> > > +     if (!timeout)
> > > +             dev_err(csi2->dev, "Clearing CSI2nRTST.VSRSTS timed out\n");
> > > +}
> > > +
> > > +static int rzg2l_csi2_mipi_link_setting(struct v4l2_subdev *sd, bool on)
> > > +{
> > > +     struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
> > > +     int ret;
> > > +
> > > +     ret = rzg2l_csi2_enable_reg_access(csi2);
> > > +     if (ret < 0)
> > > +             return ret;
> > > +
> > > +     if (on)
> > > +             rzg2l_csi2_mipi_link_enable(csi2);
> > > +     else
> > > +             rzg2l_csi2_mipi_link_disable(csi2);
> > > +
> > > +     rzg2l_csi2_disable_reg_access(csi2);
> >
> > This doesn't seem right. Runtime PM isn't just about register access.
> > You need to call pm_runtime_resume_and_get() at the beginning of
> > rzg2l_csi2_s_stream() when enabling, and pm_runtime_put_sync() at the
> > end of rzg2l_csi2_s_stream() when disabling (+ error paths for the
> > enable case).
> 
> OK, I'll make use of runtime PM in s_stream callback.
> 
> > > +
> > > +     return 0;
> > > +}
> > > +
> > > +static int rzg2l_csi2_s_stream(struct v4l2_subdev *sd, int enable)
> > > +{
> > > +     struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
> > > +     int s_stream_ret = 0;
> > > +     int ret;
> > > +
> > > +     if (enable) {
> > > +             int ret;
> > > +
> > > +             ret = rzg2l_csi2_mipi_link_setting(sd, 1);
> > > +             if (ret)
> > > +                     return ret;
> > > +
> > > +             ret = reset_control_deassert(csi2->cmn_rstb);
> > > +             if (ret)
> > > +                     goto err_mipi_link_disable;
> > > +     }
> > > +
> > > +     ret = v4l2_subdev_call(csi2->remote_source, video, s_stream, enable);
> > > +     if (ret) {
> > > +             s_stream_ret = ret;
> > > +             dev_err(csi2->dev, "s_stream failed on remote source\n");
> >
> > With
> > https://lore.kernel.org/linux-media/20221026065123.595777-1-sakari.ailus@linux.intel.com/
> > I think you can drop this error message.
> 
> Agreed, I will drop the error message.
> 
> > > +     }
> > > +
> > > +     if (enable && ret)
> > > +             goto err_assert_rstb;
> > > +
> > > +     if (!enable) {
> > > +             ret = rzg2l_csi2_dphy_setting(sd, 0);
> > > +             if (ret && !s_stream_ret)
> > > +                     s_stream_ret = ret;
> > > +             ret = rzg2l_csi2_mipi_link_setting(sd, 0);
> > > +             if (ret && !s_stream_ret)
> > > +                     s_stream_ret = ret;
> > > +     }
> > > +
> > > +     return s_stream_ret;
> > > +
> > > +err_assert_rstb:
> > > +     reset_control_assert(csi2->cmn_rstb);
> > > +err_mipi_link_disable:
> > > +     rzg2l_csi2_mipi_link_setting(sd, 0);
> > > +     return ret;
> > > +}
> > > +
> > > +static int rzg2l_csi2_pre_streamon(struct v4l2_subdev *sd, u32 flags)
> > > +{
> > > +     return rzg2l_csi2_dphy_setting(sd, 1);
> > > +}
> > > +
> > > +static int rzg2l_csi2_post_streamoff(struct v4l2_subdev *sd)
> > > +{
> > > +     struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
> > > +
> > > +     /*
> > > +      * In ideal case D-PHY will be disabled in s_stream(0) callback
> > > +      * as mentioned the HW manual. The below will only happen when
> > > +      * pre_streamon succeeds and further down the line s_stream(1)
> > > +      * fails so we need to undo things in post_streamoff.
> > > +      */
> > > +     if (csi2->dphy_enabled)
> > > +             return rzg2l_csi2_dphy_setting(sd, 0);
> > > +
> > > +     return 0;
> > > +}
> > > +
> > > +static int rzg2l_csi2_set_format(struct v4l2_subdev *sd,
> > > +                              struct v4l2_subdev_state *state,
> > > +                              struct v4l2_subdev_format *fmt)
> > > +{
> > > +     struct v4l2_mbus_framefmt *src_format;
> > > +     struct v4l2_mbus_framefmt *sink_format;
> > > +
> > > +     if (fmt->pad != RZG2L_CSI2_SINK && fmt->pad != RZG2L_CSI2_SOURCE)
> > > +             return -EINVAL;
> >
> > You can drop this check as the set_format wrapper validates the pad
> > value already.
> 
> OK, I will drop this check.
> 
> > > +
> > > +     sink_format = v4l2_subdev_get_pad_format(sd, state, RZG2L_CSI2_SINK);
> > > +     src_format = v4l2_subdev_get_pad_format(sd, state, RZG2L_CSI2_SOURCE);
> >
> > As the CSI-2 receiver can't modify the format on the output,
> > set_format() on the source pad must not modify the format. Just add
> >
> >         if (fmt->pad == RZG2L_CSI2_SOURCE) {
> >                 fmt->format = *src_format;
> >                 return 0;
> >         }
> >
> > here.
> 
> OK, I will update as above.
> 
> > > +
> > > +     if (!rzg2l_csi2_code_to_fmt(fmt->format.code))
> > > +             sink_format->code = rzg2l_csi2_formats[0].code;
> > > +     else
> > > +             sink_format->code = fmt->format.code;
> > > +
> > > +     sink_format->field = V4L2_FIELD_NONE;
> > > +     sink_format->colorspace = fmt->format.colorspace;
> > > +     sink_format->xfer_func = fmt->format.xfer_func;
> > > +     sink_format->ycbcr_enc = fmt->format.ycbcr_enc;
> > > +     sink_format->quantization = fmt->format.quantization;
> > > +     sink_format->width = clamp_t(u32, fmt->format.width,
> > > +                                  RZG2L_CSI2_MIN_WIDTH, RZG2L_CSI2_MAX_WIDTH);
> > > +     sink_format->height = clamp_t(u32, fmt->format.height,
> > > +                                   RZG2L_CSI2_MIN_HEIGHT, RZG2L_CSI2_MAX_HEIGHT);
> > > +     fmt->format = *sink_format;
> > > +
> > > +     /* propagate format to source pad */
> > > +     *src_format = *sink_format;
> > > +
> > > +     return 0;
> > > +}
> > > +
> > > +static int rzg2l_csi2_init_config(struct v4l2_subdev *sd,
> > > +                               struct v4l2_subdev_state *sd_state)
> > > +{
> > > +     struct v4l2_subdev_format fmt = { .pad = RZG2L_CSI2_SINK, };
> > > +
> > > +     fmt.format.width = RZG2L_CSI2_DEFAULT_WIDTH;
> > > +     fmt.format.height = RZG2L_CSI2_DEFAULT_HEIGHT;
> > > +     fmt.format.field = V4L2_FIELD_NONE;
> > > +     fmt.format.code = RZG2L_CSI2_DEFAULT_FMT;
> > > +     fmt.format.colorspace = V4L2_COLORSPACE_SRGB;
> > > +     fmt.format.ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
> > > +     fmt.format.quantization = V4L2_QUANTIZATION_DEFAULT;
> > > +     fmt.format.xfer_func = V4L2_XFER_FUNC_DEFAULT;
> > > +
> > > +     return rzg2l_csi2_set_format(sd, sd_state, &fmt);
> > > +}
> > > +
> > > +static int rzg2l_csi2_enum_mbus_code(struct v4l2_subdev *sd,
> > > +                                  struct v4l2_subdev_state *sd_state,
> > > +                                  struct v4l2_subdev_mbus_code_enum *code)
> > > +{
> > > +     if (code->index >= ARRAY_SIZE(rzg2l_csi2_formats))
> > > +             return -EINVAL;
> > > +
> > > +     code->code = rzg2l_csi2_formats[code->index].code;
> > > +
> > > +     return 0;
> > > +}
> > > +
> > > +static int rzg2l_csi2_enum_frame_size(struct v4l2_subdev *sd,
> > > +                                   struct v4l2_subdev_state *sd_state,
> > > +                                   struct v4l2_subdev_frame_size_enum *fse)
> > > +{
> > > +     if (fse->index != 0)
> > > +             return -EINVAL;
> > > +
> > > +     fse->min_width = RZG2L_CSI2_MIN_WIDTH;
> > > +     fse->min_height = RZG2L_CSI2_MIN_HEIGHT;
> > > +     fse->max_width = RZG2L_CSI2_MAX_WIDTH;
> > > +     fse->max_height = RZG2L_CSI2_MAX_HEIGHT;
> > > +
> > > +     return 0;
> > > +}
> > > +
> > > +static const struct v4l2_subdev_video_ops rzg2l_csi2_video_ops = {
> > > +     .s_stream = rzg2l_csi2_s_stream,
> > > +     .pre_streamon = rzg2l_csi2_pre_streamon,
> > > +     .post_streamoff = rzg2l_csi2_post_streamoff,
> > > +};
> > > +
> > > +static const struct v4l2_subdev_pad_ops rzg2l_csi2_pad_ops = {
> > > +     .enum_mbus_code = rzg2l_csi2_enum_mbus_code,
> > > +     .init_cfg = rzg2l_csi2_init_config,
> > > +     .enum_frame_size = rzg2l_csi2_enum_frame_size,
> > > +     .set_fmt = rzg2l_csi2_set_format,
> > > +     .get_fmt = v4l2_subdev_get_fmt,
> > > +};
> > > +
> > > +static const struct v4l2_subdev_ops rzg2l_csi2_subdev_ops = {
> > > +     .video  = &rzg2l_csi2_video_ops,
> > > +     .pad    = &rzg2l_csi2_pad_ops,
> > > +};
> > > +
> > > +/* -----------------------------------------------------------------------------
> > > + * Async handling and registration of subdevices and links.
> > > + */
> > > +
> > > +static int rzg2l_csi2_notify_bound(struct v4l2_async_notifier *notifier,
> > > +                                struct v4l2_subdev *subdev,
> > > +                                struct v4l2_async_subdev *asd)
> > > +{
> > > +     struct rzg2l_csi2 *csi2 = notifier_to_csi2(notifier);
> > > +
> > > +     csi2->remote_source = subdev;
> > > +
> > > +     dev_dbg(csi2->dev, "Bound subdev: %s pad\n", subdev->name);
> > > +
> > > +     return media_create_pad_link(&subdev->entity, RZG2L_CSI2_SINK,
> > > +                                  &csi2->subdev.entity, 0,
> > > +                                  MEDIA_LNK_FL_ENABLED |
> > > +                                  MEDIA_LNK_FL_IMMUTABLE);
> > > +}
> > > +
> > > +static void rzg2l_csi2_notify_unbind(struct v4l2_async_notifier *notifier,
> > > +                                  struct v4l2_subdev *subdev,
> > > +                                  struct v4l2_async_subdev *asd)
> > > +{
> > > +     struct rzg2l_csi2 *csi2 = notifier_to_csi2(notifier);
> > > +
> > > +     csi2->remote_source = NULL;
> > > +
> > > +     dev_dbg(csi2->dev, "Unbind subdev %s\n", subdev->name);
> > > +}
> > > +
> > > +static const struct v4l2_async_notifier_operations rzg2l_csi2_notify_ops = {
> > > +     .bound = rzg2l_csi2_notify_bound,
> > > +     .unbind = rzg2l_csi2_notify_unbind,
> > > +};
> > > +
> > > +static int rzg2l_csi2_parse_v4l2(struct rzg2l_csi2 *csi2,
> > > +                              struct v4l2_fwnode_endpoint *vep)
> > > +{
> > > +     /* Only port 0 endpoint 0 is valid. */
> > > +     if (vep->base.port || vep->base.id)
> > > +             return -ENOTCONN;
> > > +
> > > +     csi2->lanes = vep->bus.mipi_csi2.num_data_lanes;
> > > +
> > > +     return 0;
> > > +}
> > > +
> > > +static int rzg2l_csi2_parse_dt(struct rzg2l_csi2 *csi2)
> > > +{
> > > +     struct v4l2_fwnode_endpoint v4l2_ep = {
> > > +             .bus_type = V4L2_MBUS_CSI2_DPHY
> > > +     };
> > > +     struct v4l2_async_subdev *asd;
> > > +     struct fwnode_handle *fwnode;
> > > +     struct fwnode_handle *ep;
> > > +     int ret;
> > > +
> > > +     ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(csi2->dev), 0, 0, 0);
> > > +     if (!ep) {
> > > +             dev_err(csi2->dev, "Not connected to subdevice\n");
> > > +             return -EINVAL;
> > > +     }
> > > +
> > > +     ret = v4l2_fwnode_endpoint_parse(ep, &v4l2_ep);
> > > +     if (ret) {
> > > +             dev_err(csi2->dev, "Could not parse v4l2 endpoint\n");
> > > +             fwnode_handle_put(ep);
> > > +             return -EINVAL;
> > > +     }
> > > +
> > > +     ret = rzg2l_csi2_parse_v4l2(csi2, &v4l2_ep);
> > > +     if (ret) {
> > > +             fwnode_handle_put(ep);
> > > +             return ret;
> > > +     }
> > > +
> > > +     fwnode = fwnode_graph_get_remote_endpoint(ep);
> > > +     fwnode_handle_put(ep);
> > > +
> > > +     v4l2_async_nf_init(&csi2->notifier);
> > > +     csi2->notifier.ops = &rzg2l_csi2_notify_ops;
> > > +
> > > +     asd = v4l2_async_nf_add_fwnode(&csi2->notifier, fwnode,
> > > +                                    struct v4l2_async_subdev);
> > > +     fwnode_handle_put(fwnode);
> > > +     if (IS_ERR(asd))
> > > +             return PTR_ERR(asd);
> > > +
> > > +     ret = v4l2_async_subdev_nf_register(&csi2->subdev, &csi2->notifier);
> > > +     if (ret)
> > > +             v4l2_async_nf_cleanup(&csi2->notifier);
> > > +
> > > +     return ret;
> > > +}
> > > +
> > > +static int rzg2l_validate_csi2_lanes(struct rzg2l_csi2 *csi2)
> > > +{
> > > +     int ret = 0;
> > > +     int lanes;
> > > +
> > > +     if (csi2->lanes != 1 && csi2->lanes != 2 && csi2->lanes != 4) {
> > > +             dev_err(csi2->dev, "Unsupported number of data-lanes: %u\n",
> > > +                     csi2->lanes);
> > > +             return -EINVAL;
> > > +     }
> > > +
> > > +     ret = rzg2l_csi2_enable_reg_access(csi2);
> > > +     if (ret < 0)
> > > +             return ret;
> > > +
> > > +     /* Checking the maximum lanes support for CSI-2 module */
> > > +     lanes = (rzg2l_csi2_read(csi2, CSI2nMCG) & CSI2nMCG_SDLN) >> 8;
> > > +     if (lanes < csi2->lanes) {
> > > +             dev_err(csi2->dev,
> > > +                     "Failed to support %d data lanes\n", csi2->lanes);
> > > +             ret = -EINVAL;
> > > +     }
> > > +
> > > +     rzg2l_csi2_disable_reg_access(csi2);
> > > +
> > > +     return ret;
> > > +}
> > > +
> > > +/* -----------------------------------------------------------------------------
> > > + * Platform Device Driver.
> > > + */
> > > +
> > > +static const struct media_entity_operations rzg2l_csi2_entity_ops = {
> > > +     .link_validate = v4l2_subdev_link_validate,
> > > +};
> > > +
> > > +static int rzg2l_csi2_probe(struct platform_device *pdev)
> > > +{
> > > +     struct rzg2l_csi2 *csi2;
> > > +     struct clk *vclk;
> > > +     int ret;
> > > +
> > > +     csi2 = devm_kzalloc(&pdev->dev, sizeof(*csi2), GFP_KERNEL);
> > > +     if (!csi2)
> > > +             return -ENOMEM;
> > > +
> > > +     csi2->base = devm_platform_ioremap_resource(pdev, 0);
> > > +     if (IS_ERR(csi2->base))
> > > +             return PTR_ERR(csi2->base);
> > > +
> > > +     csi2->cmn_rstb = devm_reset_control_get_exclusive(&pdev->dev, "cmn-rstb");
> > > +     if (IS_ERR(csi2->cmn_rstb))
> > > +             return dev_err_probe(&pdev->dev, PTR_ERR(csi2->cmn_rstb),
> > > +                                  "Failed to get cpg cmn-rstb\n");
> > > +
> > > +     csi2->presetn = devm_reset_control_get_shared(&pdev->dev, "presetn");
> >
> > Is this really a shared reset control, or do you use the shared API only
> > to enable reference counting of the reset controller ?
> 
> As the CSI2 block is part of CRU itself the presetn reset (enables reg
> access) is shared with the CRU driver too hence the use of shared api.

Thanks for the confirmation.
  

Patch

diff --git a/drivers/media/platform/renesas/Kconfig b/drivers/media/platform/renesas/Kconfig
index 9fd90672ea2d..ed788e991f74 100644
--- a/drivers/media/platform/renesas/Kconfig
+++ b/drivers/media/platform/renesas/Kconfig
@@ -41,6 +41,7 @@  config VIDEO_SH_VOU
 	  Support for the Video Output Unit (VOU) on SuperH SoCs.
 
 source "drivers/media/platform/renesas/rcar-vin/Kconfig"
+source "drivers/media/platform/renesas/rzg2l-cru/Kconfig"
 
 # Mem2mem drivers
 
diff --git a/drivers/media/platform/renesas/Makefile b/drivers/media/platform/renesas/Makefile
index 3ec226ef5fd2..55854e868887 100644
--- a/drivers/media/platform/renesas/Makefile
+++ b/drivers/media/platform/renesas/Makefile
@@ -4,6 +4,7 @@ 
 #
 
 obj-y += rcar-vin/
+obj-y += rzg2l-cru/
 obj-y += vsp1/
 
 obj-$(CONFIG_VIDEO_RCAR_DRIF) += rcar_drif.o
diff --git a/drivers/media/platform/renesas/rzg2l-cru/Kconfig b/drivers/media/platform/renesas/rzg2l-cru/Kconfig
new file mode 100644
index 000000000000..57c40bb499df
--- /dev/null
+++ b/drivers/media/platform/renesas/rzg2l-cru/Kconfig
@@ -0,0 +1,17 @@ 
+# SPDX-License-Identifier: GPL-2.0
+
+config VIDEO_RZG2L_CSI2
+	tristate "RZ/G2L MIPI CSI-2 Receiver"
+	depends on ARCH_RENESAS || COMPILE_TEST
+	depends on V4L_PLATFORM_DRIVERS
+	depends on VIDEO_DEV && OF
+	select MEDIA_CONTROLLER
+	select RESET_CONTROLLER
+	select V4L2_FWNODE
+	select VIDEO_V4L2_SUBDEV_API
+	help
+	  Support for Renesas RZ/G2L (and alike SoC's) MIPI CSI-2
+	  Receiver driver.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called rzg2l-csi2.
diff --git a/drivers/media/platform/renesas/rzg2l-cru/Makefile b/drivers/media/platform/renesas/rzg2l-cru/Makefile
new file mode 100644
index 000000000000..91ea97a944e6
--- /dev/null
+++ b/drivers/media/platform/renesas/rzg2l-cru/Makefile
@@ -0,0 +1,3 @@ 
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_VIDEO_RZG2L_CSI2) += rzg2l-csi2.o
diff --git a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c
new file mode 100644
index 000000000000..2ab9e8454a04
--- /dev/null
+++ b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c
@@ -0,0 +1,885 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for Renesas RZ/G2L MIPI CSI-2 Receiver
+ *
+ * Copyright (C) 2022 Renesas Electronics Corp.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+#include <linux/sys_soc.h>
+#include <linux/units.h>
+
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-mc.h>
+#include <media/v4l2-subdev.h>
+
+/* LINK registers */
+/* Module Configuration Register */
+#define CSI2nMCG			0x0
+#define CSI2nMCG_SDLN			GENMASK(11, 8)
+
+/* Module Control Register 0 */
+#define CSI2nMCT0			0x10
+#define CSI2nMCT0_VDLN(x)		((x) << 0)
+
+/* Module Control Register 2 */
+#define CSI2nMCT2			0x18
+#define CSI2nMCT2_FRRSKW(x)		((x) << 16)
+#define CSI2nMCT2_FRRCLK(x)		((x) << 0)
+
+/* Module Control Register 3 */
+#define CSI2nMCT3			0x1c
+#define CSI2nMCT3_RXEN			BIT(0)
+
+/* Reset Control Register */
+#define CSI2nRTCT			0x28
+#define CSI2nRTCT_VSRST			BIT(0)
+
+/* Reset Status Register */
+#define CSI2nRTST			0x2c
+#define CSI2nRTST_VSRSTS		BIT(0)
+
+/* Receive Data Type Enable Low Register */
+#define CSI2nDTEL			0x60
+
+/* Receive Data Type Enable High Register */
+#define CSI2nDTEH			0x64
+
+/* DPHY registers */
+/* D-PHY Control Register 0 */
+#define CSIDPHYCTRL0			0x400
+#define CSIDPHYCTRL0_EN_LDO1200		BIT(1)
+#define CSIDPHYCTRL0_EN_BGR		BIT(0)
+
+/* D-PHY Timing Register 0 */
+#define CSIDPHYTIM0			0x404
+#define CSIDPHYTIM0_TCLK_MISS(x)	((x) << 24)
+#define CSIDPHYTIM0_T_INIT(x)		((x) << 0)
+
+/* D-PHY Timing Register 1 */
+#define CSIDPHYTIM1			0x408
+#define CSIDPHYTIM1_THS_PREPARE(x)	((x) << 24)
+#define CSIDPHYTIM1_TCLK_PREPARE(x)	((x) << 16)
+#define CSIDPHYTIM1_THS_SETTLE(x)	((x) << 8)
+#define CSIDPHYTIM1_TCLK_SETTLE(x)	((x) << 0)
+
+/* D-PHY Skew Adjustment Function */
+#define CSIDPHYSKW0			0x460
+#define CSIDPHYSKW0_UTIL_DL0_SKW_ADJ(x)	((x) & 0x3)
+#define CSIDPHYSKW0_UTIL_DL1_SKW_ADJ(x)	(((x) & 0x3) << 4)
+#define CSIDPHYSKW0_UTIL_DL2_SKW_ADJ(x)	(((x) & 0x3) << 8)
+#define CSIDPHYSKW0_UTIL_DL3_SKW_ADJ(x)	(((x) & 0x3) << 12)
+#define CSIDPHYSKW0_DEFAULT_SKW		CSIDPHYSKW0_UTIL_DL0_SKW_ADJ(1) | \
+					CSIDPHYSKW0_UTIL_DL1_SKW_ADJ(1) | \
+					CSIDPHYSKW0_UTIL_DL2_SKW_ADJ(1) | \
+					CSIDPHYSKW0_UTIL_DL3_SKW_ADJ(1)
+
+#define VSRSTS_RETRIES			20
+
+#define RZG2L_CSI2_MIN_WIDTH		320
+#define RZG2L_CSI2_MIN_HEIGHT		240
+#define RZG2L_CSI2_MAX_WIDTH		2800
+#define RZG2L_CSI2_MAX_HEIGHT		4095
+
+#define RZG2L_CSI2_DEFAULT_WIDTH	RZG2L_CSI2_MIN_WIDTH
+#define RZG2L_CSI2_DEFAULT_HEIGHT	RZG2L_CSI2_MIN_HEIGHT
+#define RZG2L_CSI2_DEFAULT_FMT		MEDIA_BUS_FMT_UYVY8_1X16
+
+enum rzg2l_csi2_pads {
+	RZG2L_CSI2_SINK = 0,
+	RZG2L_CSI2_SOURCE,
+	NR_OF_RZG2L_CSI2_PAD,
+};
+
+struct rzg2l_csi2 {
+	struct device *dev;
+	void __iomem *base;
+	struct reset_control *presetn;
+	struct reset_control *cmn_rstb;
+	struct clk *sysclk;
+	unsigned long vclk_rate;
+
+	struct v4l2_subdev subdev;
+	struct media_pad pads[NR_OF_RZG2L_CSI2_PAD];
+
+	struct v4l2_async_notifier notifier;
+	struct v4l2_subdev *remote_source;
+
+	unsigned short lanes;
+	unsigned long hsfreq;
+
+	bool dphy_enabled;
+};
+
+struct rzg2l_csi2_timings {
+	u32 t_init;
+	u32 tclk_miss;
+	u32 tclk_settle;
+	u32 ths_settle;
+	u32 tclk_prepare;
+	u32 ths_prepare;
+	u32 max_hsfreq;
+};
+
+static const struct rzg2l_csi2_timings rzg2l_csi2_global_timings[] = {
+	[0] = {
+		.max_hsfreq = 80,
+		.t_init = 79801,
+		.tclk_miss = 4,
+		.tclk_settle = 23,
+		.ths_settle = 31,
+		.tclk_prepare = 10,
+		.ths_prepare = 19,
+	},
+	[1] = {
+		.max_hsfreq = 125,
+		.t_init = 79801,
+		.tclk_miss = 4,
+		.tclk_settle = 23,
+		.ths_settle = 28,
+		.tclk_prepare = 10,
+		.ths_prepare = 19,
+	},
+	[2] = {
+		.max_hsfreq = 250,
+		.t_init = 79801,
+		.tclk_miss = 4,
+		.tclk_settle = 23,
+		.ths_settle = 22,
+		.tclk_prepare = 10,
+		.ths_prepare = 16,
+	},
+	[3] = {
+		.max_hsfreq = 360,
+		.t_init = 79801,
+		.tclk_miss = 4,
+		.tclk_settle = 18,
+		.ths_settle = 19,
+		.tclk_prepare = 10,
+		.ths_prepare = 10,
+	},
+	[4] = {
+		.max_hsfreq = 1500,
+		.t_init = 79801,
+		.tclk_miss = 4,
+		.tclk_settle = 18,
+		.ths_settle = 18,
+		.tclk_prepare = 10,
+		.ths_prepare = 10,
+	},
+};
+
+struct rzg2l_csi2_format {
+	u32 code;
+	unsigned int datatype;
+	unsigned int bpp;
+};
+
+static const struct rzg2l_csi2_format rzg2l_csi2_formats[] = {
+	{ .code = MEDIA_BUS_FMT_UYVY8_1X16,	.datatype = 0x1e, .bpp = 16 },
+};
+
+static inline struct rzg2l_csi2 *sd_to_csi2(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct rzg2l_csi2, subdev);
+}
+
+static const struct rzg2l_csi2_format *rzg2l_csi2_code_to_fmt(unsigned int code)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(rzg2l_csi2_formats); i++)
+		if (rzg2l_csi2_formats[i].code == code)
+			return &rzg2l_csi2_formats[i];
+
+	return NULL;
+}
+
+static inline struct rzg2l_csi2 *notifier_to_csi2(struct v4l2_async_notifier *n)
+{
+	return container_of(n, struct rzg2l_csi2, notifier);
+}
+
+static u32 rzg2l_csi2_read(struct rzg2l_csi2 *csi2, unsigned int reg)
+{
+	return ioread32(csi2->base + reg);
+}
+
+static void rzg2l_csi2_write(struct rzg2l_csi2 *csi2, unsigned int reg,
+			     u32 data)
+{
+	iowrite32(data, csi2->base + reg);
+}
+
+static void rzg2l_csi2_set(struct rzg2l_csi2 *csi2, unsigned int reg, u32 set)
+{
+	rzg2l_csi2_write(csi2, reg, rzg2l_csi2_read(csi2, reg) | set);
+}
+
+static void rzg2l_csi2_clr(struct rzg2l_csi2 *csi2, unsigned int reg, u32 clr)
+{
+	rzg2l_csi2_write(csi2, reg, rzg2l_csi2_read(csi2, reg) & ~clr);
+}
+
+static int rzg2l_csi2_calc_mbps(struct rzg2l_csi2 *csi2)
+{
+	struct v4l2_subdev *source = csi2->remote_source;
+	const struct rzg2l_csi2_format *format;
+	const struct v4l2_mbus_framefmt *fmt;
+	struct v4l2_subdev_state *state;
+	struct v4l2_ctrl *ctrl;
+	u64 mbps;
+
+	/* Read the pixel rate control from remote. */
+	ctrl = v4l2_ctrl_find(source->ctrl_handler, V4L2_CID_PIXEL_RATE);
+	if (!ctrl) {
+		dev_err(csi2->dev, "no pixel rate control in subdev %s\n",
+			source->name);
+		return -EINVAL;
+	}
+
+	state = v4l2_subdev_lock_and_get_active_state(&csi2->subdev);
+	fmt = v4l2_subdev_get_pad_format(&csi2->subdev, state, RZG2L_CSI2_SINK);
+	format = rzg2l_csi2_code_to_fmt(fmt->code);
+	v4l2_subdev_unlock_state(state);
+
+	/*
+	 * Calculate hsfreq in Mbps
+	 * hsfreq = (pixel_rate * bits_per_sample) / number_of_lanes
+	 */
+	mbps = v4l2_ctrl_g_ctrl_int64(ctrl) * format->bpp;
+	do_div(mbps, csi2->lanes * 1000000);
+
+	return mbps;
+}
+
+/* -----------------------------------------------------------------------------
+ * DPHY setting
+ */
+
+static int rzg2l_csi2_dphy_disable(struct rzg2l_csi2 *csi2)
+{
+	int ret;
+
+	/* Reset the CRU (D-PHY) */
+	ret = reset_control_assert(csi2->cmn_rstb);
+	if (ret)
+		return ret;
+
+	/* Stop the D-PHY clock */
+	clk_disable_unprepare(csi2->sysclk);
+
+	/* Cancel the EN_LDO1200 register setting */
+	rzg2l_csi2_clr(csi2, CSIDPHYCTRL0, CSIDPHYCTRL0_EN_LDO1200);
+
+	/* Cancel the EN_BGR register setting */
+	rzg2l_csi2_clr(csi2, CSIDPHYCTRL0, CSIDPHYCTRL0_EN_BGR);
+
+	csi2->dphy_enabled = false;
+
+	return 0;
+}
+
+static int rzg2l_csi2_dphy_enable(struct rzg2l_csi2 *csi2)
+{
+	const struct rzg2l_csi2_timings *dphy_timing;
+	u32 dphytim0, dphytim1;
+	unsigned int i;
+	int mbps;
+	int ret;
+
+	mbps = rzg2l_csi2_calc_mbps(csi2);
+	if (mbps < 0)
+		return mbps;
+
+	csi2->hsfreq = mbps;
+
+	/* Set DPHY timing parameters */
+	for (i = 0; i < ARRAY_SIZE(rzg2l_csi2_global_timings); ++i) {
+		dphy_timing = &rzg2l_csi2_global_timings[i];
+
+		if (csi2->hsfreq <= dphy_timing->max_hsfreq)
+			break;
+	}
+
+	if (i >= ARRAY_SIZE(rzg2l_csi2_global_timings))
+		return -EINVAL;
+
+	/* Set D-PHY timing parameters */
+	dphytim0 = CSIDPHYTIM0_TCLK_MISS(dphy_timing->tclk_miss) |
+			CSIDPHYTIM0_T_INIT(dphy_timing->t_init);
+	dphytim1 = CSIDPHYTIM1_THS_PREPARE(dphy_timing->ths_prepare) |
+			CSIDPHYTIM1_TCLK_PREPARE(dphy_timing->tclk_prepare) |
+			CSIDPHYTIM1_THS_SETTLE(dphy_timing->ths_settle) |
+			CSIDPHYTIM1_TCLK_SETTLE(dphy_timing->tclk_settle);
+	rzg2l_csi2_write(csi2, CSIDPHYTIM0, dphytim0);
+	rzg2l_csi2_write(csi2, CSIDPHYTIM1, dphytim1);
+
+	/* Enable D-PHY power control 0 */
+	rzg2l_csi2_write(csi2, CSIDPHYSKW0, CSIDPHYSKW0_DEFAULT_SKW);
+
+	/* Set the EN_BGR bit */
+	rzg2l_csi2_set(csi2, CSIDPHYCTRL0, CSIDPHYCTRL0_EN_BGR);
+
+	/* Delay 20us to be stable */
+	usleep_range(20, 40);
+
+	/* Enable D-PHY power control 1 */
+	rzg2l_csi2_set(csi2, CSIDPHYCTRL0, CSIDPHYCTRL0_EN_LDO1200);
+
+	/* Delay 10us to be stable */
+	usleep_range(10, 20);
+
+	/* Start supplying the internal clock for the D-PHY block */
+	ret = clk_prepare_enable(csi2->sysclk);
+	if (ret)
+		rzg2l_csi2_dphy_disable(csi2);
+
+	csi2->dphy_enabled = true;
+
+	return ret;
+}
+
+static int rzg2l_csi2_enable_reg_access(struct rzg2l_csi2 *csi2)
+{
+	int ret;
+
+	ret = reset_control_deassert(csi2->presetn);
+	if (ret < 0)
+		return ret;
+
+	ret = pm_runtime_resume_and_get(csi2->dev);
+	if (ret)
+		reset_control_assert(csi2->presetn);
+
+	return ret;
+}
+
+static void rzg2l_csi2_disable_reg_access(struct rzg2l_csi2 *csi2)
+{
+	pm_runtime_put_sync(csi2->dev);
+	reset_control_assert(csi2->presetn);
+}
+
+static int rzg2l_csi2_dphy_setting(struct v4l2_subdev *sd, bool on)
+{
+	struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
+	int ret;
+
+	ret = rzg2l_csi2_enable_reg_access(csi2);
+	if (ret < 0)
+		return ret;
+
+	if (on)
+		ret = rzg2l_csi2_dphy_enable(csi2);
+	else
+		ret = rzg2l_csi2_dphy_disable(csi2);
+
+	rzg2l_csi2_disable_reg_access(csi2);
+
+	return ret;
+}
+
+static void rzg2l_csi2_mipi_link_enable(struct rzg2l_csi2 *csi2)
+{
+	unsigned long vclk_rate = csi2->vclk_rate / HZ_PER_MHZ;
+	u32 frrskw, frrclk, frrskw_coeff, frrclk_coeff;
+
+	/* Select data lanes */
+	rzg2l_csi2_write(csi2, CSI2nMCT0, CSI2nMCT0_VDLN(csi2->lanes));
+
+	frrskw_coeff = 3 * vclk_rate * 8;
+	frrclk_coeff = frrskw_coeff / 2;
+	frrskw = DIV_ROUND_UP(frrskw_coeff, csi2->hsfreq);
+	frrclk = DIV_ROUND_UP(frrclk_coeff, csi2->hsfreq);
+	rzg2l_csi2_write(csi2, CSI2nMCT2, CSI2nMCT2_FRRSKW(frrskw) |
+			 CSI2nMCT2_FRRCLK(frrclk));
+
+	/*
+	 * Select data type.
+	 * FS, FE, LS, LE, Generic Short Packet Codes 1 to 8,
+	 * Generic Long Packet Data Types 1 to 4 YUV422 8-bit,
+	 * RGB565, RGB888, RAW8 to RAW20, User-defined 8-bit
+	 * data types 1 to 8
+	 */
+	rzg2l_csi2_write(csi2, CSI2nDTEL, 0xf778ff0f);
+	rzg2l_csi2_write(csi2, CSI2nDTEH, 0x00ffff1f);
+
+	/* Enable LINK reception */
+	rzg2l_csi2_write(csi2, CSI2nMCT3, CSI2nMCT3_RXEN);
+}
+
+static void rzg2l_csi2_mipi_link_disable(struct rzg2l_csi2 *csi2)
+{
+	unsigned int timeout = VSRSTS_RETRIES;
+
+	/* Stop LINK reception */
+	rzg2l_csi2_clr(csi2, CSI2nMCT3, CSI2nMCT3_RXEN);
+
+	/* Request a software reset of the LINK Video Pixel Interface */
+	rzg2l_csi2_write(csi2, CSI2nRTCT, CSI2nRTCT_VSRST);
+
+	/* Make sure CSI2nRTST.VSRSTS bit is cleared */
+	while (timeout--) {
+		if (!(rzg2l_csi2_read(csi2, CSI2nRTST) & CSI2nRTST_VSRSTS))
+			break;
+		usleep_range(100, 200);
+	};
+
+	if (!timeout)
+		dev_err(csi2->dev, "Clearing CSI2nRTST.VSRSTS timed out\n");
+}
+
+static int rzg2l_csi2_mipi_link_setting(struct v4l2_subdev *sd, bool on)
+{
+	struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
+	int ret;
+
+	ret = rzg2l_csi2_enable_reg_access(csi2);
+	if (ret < 0)
+		return ret;
+
+	if (on)
+		rzg2l_csi2_mipi_link_enable(csi2);
+	else
+		rzg2l_csi2_mipi_link_disable(csi2);
+
+	rzg2l_csi2_disable_reg_access(csi2);
+
+	return 0;
+}
+
+static int rzg2l_csi2_s_stream(struct v4l2_subdev *sd, int enable)
+{
+	struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
+	int s_stream_ret = 0;
+	int ret;
+
+	if (enable) {
+		int ret;
+
+		ret = rzg2l_csi2_mipi_link_setting(sd, 1);
+		if (ret)
+			return ret;
+
+		ret = reset_control_deassert(csi2->cmn_rstb);
+		if (ret)
+			goto err_mipi_link_disable;
+	}
+
+	ret = v4l2_subdev_call(csi2->remote_source, video, s_stream, enable);
+	if (ret) {
+		s_stream_ret = ret;
+		dev_err(csi2->dev, "s_stream failed on remote source\n");
+	}
+
+	if (enable && ret)
+		goto err_assert_rstb;
+
+	if (!enable) {
+		ret = rzg2l_csi2_dphy_setting(sd, 0);
+		if (ret && !s_stream_ret)
+			s_stream_ret = ret;
+		ret = rzg2l_csi2_mipi_link_setting(sd, 0);
+		if (ret && !s_stream_ret)
+			s_stream_ret = ret;
+	}
+
+	return s_stream_ret;
+
+err_assert_rstb:
+	reset_control_assert(csi2->cmn_rstb);
+err_mipi_link_disable:
+	rzg2l_csi2_mipi_link_setting(sd, 0);
+	return ret;
+}
+
+static int rzg2l_csi2_pre_streamon(struct v4l2_subdev *sd, u32 flags)
+{
+	return rzg2l_csi2_dphy_setting(sd, 1);
+}
+
+static int rzg2l_csi2_post_streamoff(struct v4l2_subdev *sd)
+{
+	struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
+
+	/*
+	 * In ideal case D-PHY will be disabled in s_stream(0) callback
+	 * as mentioned the HW manual. The below will only happen when
+	 * pre_streamon succeeds and further down the line s_stream(1)
+	 * fails so we need to undo things in post_streamoff.
+	 */
+	if (csi2->dphy_enabled)
+		return rzg2l_csi2_dphy_setting(sd, 0);
+
+	return 0;
+}
+
+static int rzg2l_csi2_set_format(struct v4l2_subdev *sd,
+				 struct v4l2_subdev_state *state,
+				 struct v4l2_subdev_format *fmt)
+{
+	struct v4l2_mbus_framefmt *src_format;
+	struct v4l2_mbus_framefmt *sink_format;
+
+	if (fmt->pad != RZG2L_CSI2_SINK && fmt->pad != RZG2L_CSI2_SOURCE)
+		return -EINVAL;
+
+	sink_format = v4l2_subdev_get_pad_format(sd, state, RZG2L_CSI2_SINK);
+	src_format = v4l2_subdev_get_pad_format(sd, state, RZG2L_CSI2_SOURCE);
+
+	if (!rzg2l_csi2_code_to_fmt(fmt->format.code))
+		sink_format->code = rzg2l_csi2_formats[0].code;
+	else
+		sink_format->code = fmt->format.code;
+
+	sink_format->field = V4L2_FIELD_NONE;
+	sink_format->colorspace = fmt->format.colorspace;
+	sink_format->xfer_func = fmt->format.xfer_func;
+	sink_format->ycbcr_enc = fmt->format.ycbcr_enc;
+	sink_format->quantization = fmt->format.quantization;
+	sink_format->width = clamp_t(u32, fmt->format.width,
+				     RZG2L_CSI2_MIN_WIDTH, RZG2L_CSI2_MAX_WIDTH);
+	sink_format->height = clamp_t(u32, fmt->format.height,
+				      RZG2L_CSI2_MIN_HEIGHT, RZG2L_CSI2_MAX_HEIGHT);
+	fmt->format = *sink_format;
+
+	/* propagate format to source pad */
+	*src_format = *sink_format;
+
+	return 0;
+}
+
+static int rzg2l_csi2_init_config(struct v4l2_subdev *sd,
+				  struct v4l2_subdev_state *sd_state)
+{
+	struct v4l2_subdev_format fmt = { .pad = RZG2L_CSI2_SINK, };
+
+	fmt.format.width = RZG2L_CSI2_DEFAULT_WIDTH;
+	fmt.format.height = RZG2L_CSI2_DEFAULT_HEIGHT;
+	fmt.format.field = V4L2_FIELD_NONE;
+	fmt.format.code = RZG2L_CSI2_DEFAULT_FMT;
+	fmt.format.colorspace = V4L2_COLORSPACE_SRGB;
+	fmt.format.ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
+	fmt.format.quantization = V4L2_QUANTIZATION_DEFAULT;
+	fmt.format.xfer_func = V4L2_XFER_FUNC_DEFAULT;
+
+	return rzg2l_csi2_set_format(sd, sd_state, &fmt);
+}
+
+static int rzg2l_csi2_enum_mbus_code(struct v4l2_subdev *sd,
+				     struct v4l2_subdev_state *sd_state,
+				     struct v4l2_subdev_mbus_code_enum *code)
+{
+	if (code->index >= ARRAY_SIZE(rzg2l_csi2_formats))
+		return -EINVAL;
+
+	code->code = rzg2l_csi2_formats[code->index].code;
+
+	return 0;
+}
+
+static int rzg2l_csi2_enum_frame_size(struct v4l2_subdev *sd,
+				      struct v4l2_subdev_state *sd_state,
+				      struct v4l2_subdev_frame_size_enum *fse)
+{
+	if (fse->index != 0)
+		return -EINVAL;
+
+	fse->min_width = RZG2L_CSI2_MIN_WIDTH;
+	fse->min_height = RZG2L_CSI2_MIN_HEIGHT;
+	fse->max_width = RZG2L_CSI2_MAX_WIDTH;
+	fse->max_height = RZG2L_CSI2_MAX_HEIGHT;
+
+	return 0;
+}
+
+static const struct v4l2_subdev_video_ops rzg2l_csi2_video_ops = {
+	.s_stream = rzg2l_csi2_s_stream,
+	.pre_streamon = rzg2l_csi2_pre_streamon,
+	.post_streamoff = rzg2l_csi2_post_streamoff,
+};
+
+static const struct v4l2_subdev_pad_ops rzg2l_csi2_pad_ops = {
+	.enum_mbus_code = rzg2l_csi2_enum_mbus_code,
+	.init_cfg = rzg2l_csi2_init_config,
+	.enum_frame_size = rzg2l_csi2_enum_frame_size,
+	.set_fmt = rzg2l_csi2_set_format,
+	.get_fmt = v4l2_subdev_get_fmt,
+};
+
+static const struct v4l2_subdev_ops rzg2l_csi2_subdev_ops = {
+	.video	= &rzg2l_csi2_video_ops,
+	.pad	= &rzg2l_csi2_pad_ops,
+};
+
+/* -----------------------------------------------------------------------------
+ * Async handling and registration of subdevices and links.
+ */
+
+static int rzg2l_csi2_notify_bound(struct v4l2_async_notifier *notifier,
+				   struct v4l2_subdev *subdev,
+				   struct v4l2_async_subdev *asd)
+{
+	struct rzg2l_csi2 *csi2 = notifier_to_csi2(notifier);
+
+	csi2->remote_source = subdev;
+
+	dev_dbg(csi2->dev, "Bound subdev: %s pad\n", subdev->name);
+
+	return media_create_pad_link(&subdev->entity, RZG2L_CSI2_SINK,
+				     &csi2->subdev.entity, 0,
+				     MEDIA_LNK_FL_ENABLED |
+				     MEDIA_LNK_FL_IMMUTABLE);
+}
+
+static void rzg2l_csi2_notify_unbind(struct v4l2_async_notifier *notifier,
+				     struct v4l2_subdev *subdev,
+				     struct v4l2_async_subdev *asd)
+{
+	struct rzg2l_csi2 *csi2 = notifier_to_csi2(notifier);
+
+	csi2->remote_source = NULL;
+
+	dev_dbg(csi2->dev, "Unbind subdev %s\n", subdev->name);
+}
+
+static const struct v4l2_async_notifier_operations rzg2l_csi2_notify_ops = {
+	.bound = rzg2l_csi2_notify_bound,
+	.unbind = rzg2l_csi2_notify_unbind,
+};
+
+static int rzg2l_csi2_parse_v4l2(struct rzg2l_csi2 *csi2,
+				 struct v4l2_fwnode_endpoint *vep)
+{
+	/* Only port 0 endpoint 0 is valid. */
+	if (vep->base.port || vep->base.id)
+		return -ENOTCONN;
+
+	csi2->lanes = vep->bus.mipi_csi2.num_data_lanes;
+
+	return 0;
+}
+
+static int rzg2l_csi2_parse_dt(struct rzg2l_csi2 *csi2)
+{
+	struct v4l2_fwnode_endpoint v4l2_ep = {
+		.bus_type = V4L2_MBUS_CSI2_DPHY
+	};
+	struct v4l2_async_subdev *asd;
+	struct fwnode_handle *fwnode;
+	struct fwnode_handle *ep;
+	int ret;
+
+	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(csi2->dev), 0, 0, 0);
+	if (!ep) {
+		dev_err(csi2->dev, "Not connected to subdevice\n");
+		return -EINVAL;
+	}
+
+	ret = v4l2_fwnode_endpoint_parse(ep, &v4l2_ep);
+	if (ret) {
+		dev_err(csi2->dev, "Could not parse v4l2 endpoint\n");
+		fwnode_handle_put(ep);
+		return -EINVAL;
+	}
+
+	ret = rzg2l_csi2_parse_v4l2(csi2, &v4l2_ep);
+	if (ret) {
+		fwnode_handle_put(ep);
+		return ret;
+	}
+
+	fwnode = fwnode_graph_get_remote_endpoint(ep);
+	fwnode_handle_put(ep);
+
+	v4l2_async_nf_init(&csi2->notifier);
+	csi2->notifier.ops = &rzg2l_csi2_notify_ops;
+
+	asd = v4l2_async_nf_add_fwnode(&csi2->notifier, fwnode,
+				       struct v4l2_async_subdev);
+	fwnode_handle_put(fwnode);
+	if (IS_ERR(asd))
+		return PTR_ERR(asd);
+
+	ret = v4l2_async_subdev_nf_register(&csi2->subdev, &csi2->notifier);
+	if (ret)
+		v4l2_async_nf_cleanup(&csi2->notifier);
+
+	return ret;
+}
+
+static int rzg2l_validate_csi2_lanes(struct rzg2l_csi2 *csi2)
+{
+	int ret = 0;
+	int lanes;
+
+	if (csi2->lanes != 1 && csi2->lanes != 2 && csi2->lanes != 4) {
+		dev_err(csi2->dev, "Unsupported number of data-lanes: %u\n",
+			csi2->lanes);
+		return -EINVAL;
+	}
+
+	ret = rzg2l_csi2_enable_reg_access(csi2);
+	if (ret < 0)
+		return ret;
+
+	/* Checking the maximum lanes support for CSI-2 module */
+	lanes = (rzg2l_csi2_read(csi2, CSI2nMCG) & CSI2nMCG_SDLN) >> 8;
+	if (lanes < csi2->lanes) {
+		dev_err(csi2->dev,
+			"Failed to support %d data lanes\n", csi2->lanes);
+		ret = -EINVAL;
+	}
+
+	rzg2l_csi2_disable_reg_access(csi2);
+
+	return ret;
+}
+
+/* -----------------------------------------------------------------------------
+ * Platform Device Driver.
+ */
+
+static const struct media_entity_operations rzg2l_csi2_entity_ops = {
+	.link_validate = v4l2_subdev_link_validate,
+};
+
+static int rzg2l_csi2_probe(struct platform_device *pdev)
+{
+	struct rzg2l_csi2 *csi2;
+	struct clk *vclk;
+	int ret;
+
+	csi2 = devm_kzalloc(&pdev->dev, sizeof(*csi2), GFP_KERNEL);
+	if (!csi2)
+		return -ENOMEM;
+
+	csi2->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(csi2->base))
+		return PTR_ERR(csi2->base);
+
+	csi2->cmn_rstb = devm_reset_control_get_exclusive(&pdev->dev, "cmn-rstb");
+	if (IS_ERR(csi2->cmn_rstb))
+		return dev_err_probe(&pdev->dev, PTR_ERR(csi2->cmn_rstb),
+				     "Failed to get cpg cmn-rstb\n");
+
+	csi2->presetn = devm_reset_control_get_shared(&pdev->dev, "presetn");
+	if (IS_ERR(csi2->presetn))
+		return dev_err_probe(&pdev->dev, PTR_ERR(csi2->presetn),
+				     "Failed to get cpg presetn\n");
+
+	csi2->sysclk = devm_clk_get(&pdev->dev, "system");
+	if (IS_ERR(csi2->sysclk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(csi2->sysclk),
+				     "Failed to get system clk\n");
+
+	vclk = clk_get(&pdev->dev, "video");
+	if (IS_ERR(vclk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(vclk),
+				     "Failed to get video clock\n");
+	csi2->vclk_rate = clk_get_rate(vclk);
+	clk_put(vclk);
+
+	csi2->dev = &pdev->dev;
+
+	platform_set_drvdata(pdev, csi2);
+
+	ret = rzg2l_csi2_parse_dt(csi2);
+	if (ret)
+		return ret;
+
+	pm_runtime_enable(&pdev->dev);
+
+	ret = rzg2l_validate_csi2_lanes(csi2);
+	if (ret)
+		goto error_pm;
+
+	csi2->subdev.dev = &pdev->dev;
+	v4l2_subdev_init(&csi2->subdev, &rzg2l_csi2_subdev_ops);
+	v4l2_set_subdevdata(&csi2->subdev, &pdev->dev);
+	snprintf(csi2->subdev.name, sizeof(csi2->subdev.name),
+		 "csi-%s", dev_name(&pdev->dev));
+	csi2->subdev.flags = V4L2_SUBDEV_FL_HAS_DEVNODE;
+
+	csi2->subdev.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
+	csi2->subdev.entity.ops = &rzg2l_csi2_entity_ops;
+
+	csi2->pads[RZG2L_CSI2_SINK].flags = MEDIA_PAD_FL_SINK;
+	/*
+	 * TODO: RZ/G2L CSI2 supports 4 virtual channels, as virtual
+	 * channels should be implemented by streams API which is under
+	 * development lets hardcode to VC0 for now.
+	 */
+	csi2->pads[RZG2L_CSI2_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
+	ret = media_entity_pads_init(&csi2->subdev.entity, 2, csi2->pads);
+	if (ret)
+		goto error_pm;
+
+	ret = v4l2_subdev_init_finalize(&csi2->subdev);
+	if (ret < 0)
+		goto error_async;
+
+	ret = v4l2_async_register_subdev(&csi2->subdev);
+	if (ret < 0)
+		goto error_subdev;
+
+	return 0;
+
+error_subdev:
+	v4l2_subdev_cleanup(&csi2->subdev);
+error_async:
+	v4l2_async_nf_unregister(&csi2->notifier);
+	v4l2_async_nf_cleanup(&csi2->notifier);
+	media_entity_cleanup(&csi2->subdev.entity);
+error_pm:
+	pm_runtime_disable(&pdev->dev);
+
+	return ret;
+}
+
+static int rzg2l_csi2_remove(struct platform_device *pdev)
+{
+	struct rzg2l_csi2 *csi2 = platform_get_drvdata(pdev);
+
+	v4l2_async_nf_unregister(&csi2->notifier);
+	v4l2_async_nf_cleanup(&csi2->notifier);
+	v4l2_async_unregister_subdev(&csi2->subdev);
+	v4l2_subdev_cleanup(&csi2->subdev);
+	media_entity_cleanup(&csi2->subdev.entity);
+	pm_runtime_disable(&pdev->dev);
+
+	return 0;
+}
+
+static const struct of_device_id rzg2l_csi2_of_table[] = {
+	{ .compatible = "renesas,rzg2l-csi2", },
+	{ /* sentinel */ }
+};
+
+static struct platform_driver rzg2l_csi2_pdrv = {
+	.remove	= rzg2l_csi2_remove,
+	.probe	= rzg2l_csi2_probe,
+	.driver	= {
+		.name = "rzg2l-csi2",
+		.of_match_table = rzg2l_csi2_of_table,
+	},
+};
+
+module_platform_driver(rzg2l_csi2_pdrv);
+
+MODULE_AUTHOR("Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>");
+MODULE_DESCRIPTION("Renesas RZ/G2L MIPI CSI2 receiver driver");
+MODULE_LICENSE("GPL");