[RFC,3/5] mtd: nand: qpic_common: Add support for qpic common API

Message ID 20231031120307.1600689-4-quic_mdalam@quicinc.com
State New
Headers
Series Add QPIC SPI NAND driver support |

Commit Message

Md Sadre Alam Oct. 31, 2023, 12:03 p.m. UTC
  Add qpic command API in sperate file so that it will be
use by both spi and request and raw nand request.

Signed-off-by: Md Sadre Alam <quic_mdalam@quicinc.com>
Signed-off-by: Sricharan R <quic_srichara@quicinc.com>
---
 drivers/mtd/nand/qpic_common.c       | 840 +++++++++++++++++++++++++++
 include/linux/mtd/nand-qpic-common.h | 641 ++++++++++++++++++++
 2 files changed, 1481 insertions(+)
 create mode 100644 drivers/mtd/nand/qpic_common.c
 create mode 100644 include/linux/mtd/nand-qpic-common.h
  

Comments

Miquel Raynal Oct. 31, 2023, 3:54 p.m. UTC | #1
Hi,

quic_mdalam@quicinc.com wrote on Tue, 31 Oct 2023 17:33:05 +0530:

> Add qpic command API in sperate file so that it will be
> use by both spi and request and raw nand request.

		nand?

> 
> Signed-off-by: Md Sadre Alam <quic_mdalam@quicinc.com>
> Signed-off-by: Sricharan R <quic_srichara@quicinc.com>
> ---
>  drivers/mtd/nand/qpic_common.c       | 840 +++++++++++++++++++++++++++
>  include/linux/mtd/nand-qpic-common.h | 641 ++++++++++++++++++++
>  2 files changed, 1481 insertions(+)
>  create mode 100644 drivers/mtd/nand/qpic_common.c
>  create mode 100644 include/linux/mtd/nand-qpic-common.h
> 
> diff --git a/drivers/mtd/nand/qpic_common.c b/drivers/mtd/nand/qpic_common.c
> new file mode 100644
> index 000000000000..983768a1ea94
> --- /dev/null
> +++ b/drivers/mtd/nand/qpic_common.c
> @@ -0,0 +1,840 @@
> +// SPDX-License-Identifier: GPL-2.0 OR MIT
> +/*
> + * QPIC common API file.
> + * Copyright (C) 2023  Qualcomm Inc.
> + * Authors:	Md sadre Alam		<quic_mdalam@quicinc.com>
> + *		Sricharan R		<quic_srichara@quicinc.com>
> + */
> +
> +#include <linux/mtd/nand-qpic-common.h>
> +
> +/* Frees the BAM transaction memory */
> +void free_bam_transaction(struct qcom_nand_controller *nandc)

This is not a generic object, it's not meant to be shared with spi. So
if it's meant to be used in a single place, please don't share it.
Otherwise please use a more generic name.

> +{
> +	struct bam_transaction *bam_txn = nandc->bam_txn;
> +
> +	devm_kfree(nandc->dev, bam_txn);
> +}
> +EXPORT_SYMBOL(free_bam_transaction);
> +
> +/* Callback for DMA descriptor completion */
> +void qpic_bam_dma_done(void *data)
> +{
> +	struct bam_transaction *bam_txn = data;

Just provide the right pointer in the first place.

> +
> +	/*
> +	 * In case of data transfer with NAND, 2 callbacks will be generated.

What if we are not dealing with a NAND?

> +	 * One for command channel and another one for data channel.
> +	 * If current transaction has data descriptors
> +	 * (i.e. wait_second_completion is true), then set this to false

Why do you need a boolean for that if having a data descriptor is the
condition you want to check against?

> +	 * and wait for second DMA descriptor completion.
> +	 */
> +	if (bam_txn->wait_second_completion)
> +		bam_txn->wait_second_completion = false;

This looks very racy.

> +	else
> +		complete(&bam_txn->txn_done);
> +}
> +EXPORT_SYMBOL(qpic_bam_dma_done);
> +
> +u32 nandc_read(struct qcom_nand_controller *nandc, int offset)
> +{
> +	return ioread32(nandc->base + offset);

I don't see the need for that.

> +}
> +EXPORT_SYMBOL(nandc_read);
> +
> +void nandc_write(struct qcom_nand_controller *nandc, int offset,
> +			       u32 val)
> +{
> +	iowrite32(val, nandc->base + offset);

Same here.

> +}
> +EXPORT_SYMBOL(nandc_write);
> +
> +void nandc_read_buffer_sync(struct qcom_nand_controller *nandc,
> +					  bool is_cpu)
> +{
> +	if (!nandc->props->is_bam)
> +		return;

I thought BAM was a per transaction thing, and here you check it
against a controller parameter. It looks wrong.

> +
> +	if (is_cpu)

Whuut? naming, naming, naming, naming. Please.

> +		dma_sync_single_for_cpu(nandc->dev, nandc->reg_read_dma,
> +					MAX_REG_RD *

Remove this new line

> +					sizeof(*nandc->reg_read_buf),

Are you sure this sizeof() is safe?

> +					DMA_FROM_DEVICE);
> +	else
> +		dma_sync_single_for_device(nandc->dev, nandc->reg_read_dma,
> +					   MAX_REG_RD *
> +					   sizeof(*nandc->reg_read_buf),
> +					   DMA_FROM_DEVICE);
> +}

You better have a really good reason to sync in the middle of an
operation...

> +EXPORT_SYMBOL(nandc_read_buffer_sync);
> +
> +__le32 *offset_to_nandc_reg(struct nandc_regs *regs, int offset)
> +{
> +	switch (offset) {
> +	case NAND_FLASH_CMD:
> +		return &regs->cmd;
> +	case NAND_ADDR0:
> +		return &regs->addr0;
> +	case NAND_ADDR1:
> +		return &regs->addr1;
> +	case NAND_FLASH_CHIP_SELECT:
> +		return &regs->chip_sel;
> +	case NAND_EXEC_CMD:
> +		return &regs->exec;
> +	case NAND_FLASH_STATUS:
> +		return &regs->clrflashstatus;
> +	case NAND_DEV0_CFG0:
> +		return &regs->cfg0;
> +	case NAND_DEV0_CFG1:
> +		return &regs->cfg1;
> +	case NAND_DEV0_ECC_CFG:
> +		return &regs->ecc_bch_cfg;
> +	case NAND_READ_STATUS:
> +		return &regs->clrreadstatus;
> +	case NAND_DEV_CMD1:
> +		return &regs->cmd1;
> +	case NAND_DEV_CMD1_RESTORE:
> +		return &regs->orig_cmd1;
> +	case NAND_DEV_CMD_VLD:
> +		return &regs->vld;
> +	case NAND_DEV_CMD_VLD_RESTORE:
> +		return &regs->orig_vld;
> +	case NAND_EBI2_ECC_BUF_CFG:
> +		return &regs->ecc_buf_cfg;
> +	case NAND_READ_LOCATION_0:
> +		return &regs->read_location0;
> +	case NAND_READ_LOCATION_1:
> +		return &regs->read_location1;
> +	case NAND_READ_LOCATION_2:
> +		return &regs->read_location2;
> +	case NAND_READ_LOCATION_3:
> +		return &regs->read_location3;
> +	case NAND_READ_LOCATION_LAST_CW_0:
> +		return &regs->read_location_last0;
> +	case NAND_READ_LOCATION_LAST_CW_1:
> +		return &regs->read_location_last1;
> +	case NAND_READ_LOCATION_LAST_CW_2:
> +		return &regs->read_location_last2;
> +	case NAND_READ_LOCATION_LAST_CW_3:
> +		return &regs->read_location_last3;
> +	case NAND_FLASH_SPI_CFG:
> +		return &regs->spi_cfg;
> +	case NAND_NUM_ADDR_CYCLES:
> +		return &regs->num_addr_cycle;
> +	case NAND_BUSY_CHECK_WAIT_CNT:
> +		return &regs->busy_wait_cnt;
> +	case NAND_MSTR_CONFIG:
> +		return &regs->mstr_cfg;
> +	case NAND_FLASH_FEATURES:
> +		return &regs->flash_feature;

Just... no? What is the point of using an intermediate int here? just
dereference the right value?

> +	default:
> +		return NULL;
> +	}
> +}
> +EXPORT_SYMBOL(offset_to_nandc_reg);
> +
> +/* reset the register read buffer for next NAND operation */
> +void clear_read_regs(struct qcom_nand_controller *nandc)
> +{
> +	nandc->reg_read_pos = 0;
> +	nandc_read_buffer_sync(nandc, false);
> +}
> +EXPORT_SYMBOL(clear_read_regs);
> +
> +int prep_adm_dma_desc(struct qcom_nand_controller *nandc, bool read,

adm?


Please always prefix your symbols (especially when exporting them) with
a decent a easy to recognize prefix.

> +			     int reg_off, const void *vaddr, int size,
> +			     bool flow_control)
> +{
> +	struct desc_info *desc;
> +	struct dma_async_tx_descriptor *dma_desc;
> +	struct scatterlist *sgl;
> +	struct dma_slave_config slave_conf;
> +	struct qcom_adm_peripheral_config periph_conf = {};
> +	enum dma_transfer_direction dir_eng;
> +	int ret;
> +
> +	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
> +	if (!desc)
> +		return -ENOMEM;
> +
> +	sgl = &desc->adm_sgl;
> +
> +	sg_init_one(sgl, vaddr, size);
> +
> +	if (read) {
> +		dir_eng = DMA_DEV_TO_MEM;
> +		desc->dir = DMA_FROM_DEVICE;
> +	} else {
> +		dir_eng = DMA_MEM_TO_DEV;
> +		desc->dir = DMA_TO_DEVICE;
> +	}
> +
> +	ret = dma_map_sg(nandc->dev, sgl, 1, desc->dir);
> +	if (ret == 0) {
> +		ret = -ENOMEM;
> +		goto err;
> +	}
> +
> +	memset(&slave_conf, 0x00, sizeof(slave_conf));
> +
> +	slave_conf.device_fc = flow_control;
> +	if (read) {
> +		slave_conf.src_maxburst = 16;
> +		slave_conf.src_addr = nandc->base_dma + reg_off;
> +		if (nandc->data_crci) {
> +			periph_conf.crci = nandc->data_crci;
> +			slave_conf.peripheral_config = &periph_conf;
> +			slave_conf.peripheral_size = sizeof(periph_conf);
> +		}
> +	} else {
> +		slave_conf.dst_maxburst = 16;
> +		slave_conf.dst_addr = nandc->base_dma + reg_off;
> +		if (nandc->cmd_crci) {
> +			periph_conf.crci = nandc->cmd_crci;
> +			slave_conf.peripheral_config = &periph_conf;
> +			slave_conf.peripheral_size = sizeof(periph_conf);
> +		}
> +	}
> +
> +	ret = dmaengine_slave_config(nandc->chan, &slave_conf);
> +	if (ret) {
> +		dev_err(nandc->dev, "failed to configure dma channel\n");
> +		goto err;
> +	}
> +
> +	dma_desc = dmaengine_prep_slave_sg(nandc->chan, sgl, 1, dir_eng, 0);
> +	if (!dma_desc) {
> +		dev_err(nandc->dev, "failed to prepare desc\n");
> +		ret = -EINVAL;
> +		goto err;
> +	}
> +
> +	desc->dma_desc = dma_desc;
> +
> +	list_add_tail(&desc->node, &nandc->desc_list);
> +
> +	return 0;
> +err:

your error path is missing steps

> +	kfree(desc);
> +
> +	return ret;
> +}
> +
> +/* helpers to submit/free our list of dma descriptors */
> +int submit_descs(struct qcom_nand_controller *nandc)
> +{
> +	struct desc_info *desc;
> +	dma_cookie_t cookie = 0;
> +	struct bam_transaction *bam_txn = nandc->bam_txn;
> +	int r;
> +
> +	if (nandc->props->is_bam) {
> +		if (bam_txn->rx_sgl_pos > bam_txn->rx_sgl_start) {
> +			r = prepare_bam_async_desc(nandc, nandc->rx_chan, 0);
> +			if (r)
> +				return r;
> +		}
> +
> +		if (bam_txn->tx_sgl_pos > bam_txn->tx_sgl_start) {
> +			r = prepare_bam_async_desc(nandc, nandc->tx_chan,
> +						   DMA_PREP_INTERRUPT);
> +			if (r)
> +				return r;
> +		}
> +
> +		if (bam_txn->cmd_sgl_pos > bam_txn->cmd_sgl_start) {
> +			r = prepare_bam_async_desc(nandc, nandc->cmd_chan,
> +						   DMA_PREP_CMD);
> +			if (r)
> +				return r;
> +		}
> +	}
> +
> +	list_for_each_entry(desc, &nandc->desc_list, node)
> +		cookie = dmaengine_submit(desc->dma_desc);
> +
> +	if (nandc->props->is_bam) {
> +		bam_txn->last_cmd_desc->callback = qpic_bam_dma_done;
> +		bam_txn->last_cmd_desc->callback_param = bam_txn;
> +		if (bam_txn->last_data_desc) {
> +			bam_txn->last_data_desc->callback = qpic_bam_dma_done;
> +			bam_txn->last_data_desc->callback_param = bam_txn;
> +			bam_txn->wait_second_completion = true;
> +		}
> +
> +		dma_async_issue_pending(nandc->tx_chan);
> +		dma_async_issue_pending(nandc->rx_chan);
> +		dma_async_issue_pending(nandc->cmd_chan);
> +
> +		if (!wait_for_completion_timeout(&bam_txn->txn_done,
> +						 QPIC_NAND_COMPLETION_TIMEOUT))
> +			return -ETIMEDOUT;
> +	} else {
> +		if (dma_sync_wait(nandc->chan, cookie) != DMA_COMPLETE)
> +			return -ETIMEDOUT;
> +	}
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(submit_descs);
> +
> +void free_descs(struct qcom_nand_controller *nandc)
> +{
> +	struct desc_info *desc, *n;
> +
> +	list_for_each_entry_safe(desc, n, &nandc->desc_list, node) {
> +		list_del(&desc->node);
> +
> +		if (nandc->props->is_bam)
> +			dma_unmap_sg(nandc->dev, desc->bam_sgl,
> +				     desc->sgl_cnt, desc->dir);
> +		else
> +			dma_unmap_sg(nandc->dev, &desc->adm_sgl, 1,
> +				     desc->dir);
> +
> +		kfree(desc);
> +	}
> +}
> +EXPORT_SYMBOL(free_descs);
> +
> +/*
> + * Maps the scatter gather list for DMA transfer and forms the DMA descriptor
> + * for BAM. This descriptor will be added in the NAND DMA descriptor queue
> + * which will be submitted to DMA engine.
> + */
> +int prepare_bam_async_desc(struct qcom_nand_controller *nandc,
> +				  struct dma_chan *chan,
> +				  unsigned long flags)
> +{
> +	struct desc_info *desc;
> +	struct scatterlist *sgl;
> +	unsigned int sgl_cnt;
> +	int ret;
> +	struct bam_transaction *bam_txn = nandc->bam_txn;
> +	enum dma_transfer_direction dir_eng;
> +	struct dma_async_tx_descriptor *dma_desc;
> +
> +	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
> +	if (!desc)
> +		return -ENOMEM;
> +
> +	if (chan == nandc->cmd_chan) {
> +		sgl = &bam_txn->cmd_sgl[bam_txn->cmd_sgl_start];
> +		sgl_cnt = bam_txn->cmd_sgl_pos - bam_txn->cmd_sgl_start;
> +		bam_txn->cmd_sgl_start = bam_txn->cmd_sgl_pos;
> +		dir_eng = DMA_MEM_TO_DEV;
> +		desc->dir = DMA_TO_DEVICE;
> +	} else if (chan == nandc->tx_chan) {
> +		sgl = &bam_txn->data_sgl[bam_txn->tx_sgl_start];
> +		sgl_cnt = bam_txn->tx_sgl_pos - bam_txn->tx_sgl_start;
> +		bam_txn->tx_sgl_start = bam_txn->tx_sgl_pos;
> +		dir_eng = DMA_MEM_TO_DEV;
> +		desc->dir = DMA_TO_DEVICE;
> +	} else {
> +		sgl = &bam_txn->data_sgl[bam_txn->rx_sgl_start];
> +		sgl_cnt = bam_txn->rx_sgl_pos - bam_txn->rx_sgl_start;
> +		bam_txn->rx_sgl_start = bam_txn->rx_sgl_pos;
> +		dir_eng = DMA_DEV_TO_MEM;
> +		desc->dir = DMA_FROM_DEVICE;
> +	}
> +
> +	sg_mark_end(sgl + sgl_cnt - 1);
> +	ret = dma_map_sg(nandc->dev, sgl, sgl_cnt, desc->dir);
> +	if (ret == 0) {
> +		dev_err(nandc->dev, "failure in mapping desc\n");
> +		kfree(desc);
> +		return -ENOMEM;
> +	}
> +
> +	desc->sgl_cnt = sgl_cnt;
> +	desc->bam_sgl = sgl;
> +
> +	dma_desc = dmaengine_prep_slave_sg(chan, sgl, sgl_cnt, dir_eng,
> +					   flags);
> +
> +	if (!dma_desc) {
> +		dev_err(nandc->dev, "failure in prep desc\n");
> +		dma_unmap_sg(nandc->dev, sgl, sgl_cnt, desc->dir);
> +		kfree(desc);
> +		return -EINVAL;
> +	}
> +
> +	desc->dma_desc = dma_desc;
> +
> +	/* update last data/command descriptor */
> +	if (chan == nandc->cmd_chan)
> +		bam_txn->last_cmd_desc = dma_desc;
> +	else
> +		bam_txn->last_data_desc = dma_desc;
> +
> +	list_add_tail(&desc->node, &nandc->desc_list);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(prepare_bam_async_desc);
> +
> +/*
> + * Prepares the command descriptor for BAM DMA which will be used for NAND
> + * register reads and writes. The command descriptor requires the command
> + * to be formed in command element type so this function uses the command
> + * element from bam transaction ce array and fills the same with required

ce?

> + * data. A single SGL can contain multiple command elements so
> + * NAND_BAM_NEXT_SGL will be used for starting the separate SGL
> + * after the current command element.
> + */
> +int prep_bam_dma_desc_cmd(struct qcom_nand_controller *nandc, bool read,
> +				 int reg_off, const void *vaddr,
> +				 int size, unsigned int flags)
> +{
> +	int bam_ce_size;
> +	int i, ret;
> +	struct bam_cmd_element *bam_ce_buffer;
> +	struct bam_transaction *bam_txn = nandc->bam_txn;
> +
> +	bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_pos];
> +
> +	/* fill the command desc */
> +	for (i = 0; i < size; i++) {
> +		if (read)
> +			bam_prep_ce(&bam_ce_buffer[i],
> +				    nandc_reg_phys(nandc, reg_off + 4 * i),
> +				    BAM_READ_COMMAND,
> +				    reg_buf_dma_addr(nandc,
> +						     (__le32 *)vaddr + i));
> +		else
> +			bam_prep_ce_le32(&bam_ce_buffer[i],
> +					 nandc_reg_phys(nandc, reg_off + 4 * i),
> +					 BAM_WRITE_COMMAND,
> +					 *((__le32 *)vaddr + i));

The _le handling looks really fragile.

> +	}
> +
> +	bam_txn->bam_ce_pos += size;
> +
> +	/* use the separate sgl after this command */
> +	if (flags & NAND_BAM_NEXT_SGL) {
> +		bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_start];
> +		bam_ce_size = (bam_txn->bam_ce_pos -
> +				bam_txn->bam_ce_start) *
> +				sizeof(struct bam_cmd_element);
> +		sg_set_buf(&bam_txn->cmd_sgl[bam_txn->cmd_sgl_pos],
> +			   bam_ce_buffer, bam_ce_size);
> +		bam_txn->cmd_sgl_pos++;
> +		bam_txn->bam_ce_start = bam_txn->bam_ce_pos;
> +
> +		if (flags & NAND_BAM_NWD) {
> +			ret = prepare_bam_async_desc(nandc, nandc->cmd_chan,
> +						     DMA_PREP_FENCE |
> +						     DMA_PREP_CMD);
> +			if (ret)
> +				return ret;
> +		}
> +	}
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(prep_bam_dma_desc_cmd);
> +
> +/*
> + * Prepares the data descriptor for BAM DMA which will be used for NAND
> + * data reads and writes.
> + */
> +int prep_bam_dma_desc_data(struct qcom_nand_controller *nandc, bool read,
> +				  const void *vaddr,
> +				  int size, unsigned int flags)
> +{
> +	int ret;
> +	struct bam_transaction *bam_txn = nandc->bam_txn;
> +
> +	if (read) {
> +		sg_set_buf(&bam_txn->data_sgl[bam_txn->rx_sgl_pos],
> +			   vaddr, size);
> +		bam_txn->rx_sgl_pos++;
> +	} else {
> +		sg_set_buf(&bam_txn->data_sgl[bam_txn->tx_sgl_pos],
> +			   vaddr, size);
> +		bam_txn->tx_sgl_pos++;
> +
> +		/*
> +		 * BAM will only set EOT for DMA_PREP_INTERRUPT so if this flag
> +		 * is not set, form the DMA descriptor
> +		 */
> +		if (!(flags & NAND_BAM_NO_EOT)) {
> +			ret = prepare_bam_async_desc(nandc, nandc->tx_chan,
> +						     DMA_PREP_INTERRUPT);
> +			if (ret)
> +				return ret;
> +		}
> +	}
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(prep_bam_dma_desc_data);
> +
> +/*
> + * read_reg_dma:	prepares a descriptor to read a given number of
> + *			contiguous registers to the reg_read_buf pointer
> + *
> + * @first:		offset of the first register in the contiguous block
> + * @num_regs:		number of registers to read
> + * @flags:		flags to control DMA descriptor preparation
> + */
> +int read_reg_dma(struct qcom_nand_controller *nandc, int first,
> +			int num_regs, unsigned int flags)
> +{
> +	bool flow_control = false;
> +	void *vaddr;
> +
> +	vaddr = nandc->reg_read_buf + nandc->reg_read_pos;
> +	nandc->reg_read_pos += num_regs;
> +
> +	if (first == NAND_DEV_CMD_VLD || first == NAND_DEV_CMD1)
> +		first = dev_cmd_reg_addr(nandc, first);
> +
> +	if (nandc->props->is_bam)
> +		return prep_bam_dma_desc_cmd(nandc, true, first, vaddr,
> +					     num_regs, flags);
> +
> +	if (first == NAND_READ_ID || first == NAND_FLASH_STATUS)
> +		flow_control = true;

This flow_control property really bothers me.

> +
> +	return prep_adm_dma_desc(nandc, true, first, vaddr,
> +				 num_regs * sizeof(u32), flow_control);
> +}
> +EXPORT_SYMBOL(read_reg_dma);
> +
> +/*
> + * write_reg_dma:	prepares a descriptor to write a given number of
> + *			contiguous registers
> + *
> + * @first:		offset of the first register in the contiguous block
> + * @num_regs:		number of registers to write
> + * @flags:		flags to control DMA descriptor preparation
> + */
> +int write_reg_dma(struct qcom_nand_controller *nandc, int first,
> +			 int num_regs, unsigned int flags)
> +{
> +	bool flow_control = false;
> +	struct nandc_regs *regs = nandc->regs;
> +	void *vaddr;
> +
> +	vaddr = offset_to_nandc_reg(regs, first);
> +
> +	if (first == NAND_ERASED_CW_DETECT_CFG) {
> +		if (flags & NAND_ERASED_CW_SET)
> +			vaddr = &regs->erased_cw_detect_cfg_set;
> +		else
> +			vaddr = &regs->erased_cw_detect_cfg_clr;
> +	}
> +
> +	if (first == NAND_EXEC_CMD)
> +		flags |= NAND_BAM_NWD;
> +
> +	if (first == NAND_FLASH_SPI_CFG || first == NAND_NUM_ADDR_CYCLES
> +		|| first == NAND_BUSY_CHECK_WAIT_CNT
> +		|| first == NAND_MSTR_CONFIG)
> +		first = dev_cmd_reg_addr(nandc, first);
> +
> +	if (first == NAND_DEV_CMD1_RESTORE || first == NAND_DEV_CMD1)
> +		first = dev_cmd_reg_addr(nandc, NAND_DEV_CMD1);
> +
> +	if (first == NAND_DEV_CMD_VLD_RESTORE || first == NAND_DEV_CMD_VLD)
> +		first = dev_cmd_reg_addr(nandc, NAND_DEV_CMD_VLD);
> +

What about a switch case here?

> +	if (nandc->props->is_bam)
> +		return prep_bam_dma_desc_cmd(nandc, false, first, vaddr,
> +					     num_regs, flags);
> +
> +	if (first == NAND_FLASH_CMD)
> +		flow_control = true;
> +
> +	return prep_adm_dma_desc(nandc, false, first, vaddr,
> +				 num_regs * sizeof(u32), flow_control);
> +}
> +EXPORT_SYMBOL(write_reg_dma);
> +
> +/*
> + * read_data_dma:	prepares a DMA descriptor to transfer data from the
> + *			controller's internal buffer to the buffer 'vaddr'
> + *
> + * @reg_off:		offset within the controller's data buffer
> + * @vaddr:		virtual address of the buffer we want to write to
> + * @size:		DMA transaction size in bytes
> + * @flags:		flags to control DMA descriptor preparation
> + */
> +int read_data_dma(struct qcom_nand_controller *nandc, int reg_off,
> +			 const u8 *vaddr, int size, unsigned int flags)
> +{
> +	if (nandc->props->is_bam)
> +		return prep_bam_dma_desc_data(nandc, true, vaddr, size, flags);
> +
> +	return prep_adm_dma_desc(nandc, true, reg_off, vaddr, size, false);
> +}
> +EXPORT_SYMBOL(read_data_dma);
> +
> +/*
> + * write_data_dma:	prepares a DMA descriptor to transfer data from
> + *			'vaddr' to the controller's internal buffer
> + *
> + * @reg_off:		offset within the controller's data buffer
> + * @vaddr:		virtual address of the buffer we want to read from
> + * @size:		DMA transaction size in bytes
> + * @flags:		flags to control DMA descriptor preparation
> + */
> +int write_data_dma(struct qcom_nand_controller *nandc, int reg_off,
> +			  const u8 *vaddr, int size, unsigned int flags)
> +{
> +	if (nandc->props->is_bam)
> +		return prep_bam_dma_desc_data(nandc, false, vaddr, size, flags);
> +
> +	return prep_adm_dma_desc(nandc, false, reg_off, vaddr, size, false);
> +}
> +EXPORT_SYMBOL(write_data_dma);
> +
> +void nandc_set_reg(struct qcom_nand_controller *nandc, int offset,
> +			  u32 val)
> +{
> +	struct nandc_regs *regs = nandc->regs;
> +	__le32 *reg;
> +
> +	reg = offset_to_nandc_reg(regs, offset);
> +	if (reg)
> +		*reg = cpu_to_le32(val);
> +}
> +EXPORT_SYMBOL(nandc_set_reg);
> +
> +/* Allocates and Initializes the BAM transaction */
> +struct bam_transaction *
> +alloc_bam_transaction(struct qcom_nand_controller *nandc)
> +{
> +	struct bam_transaction *bam_txn;
> +	size_t bam_txn_size;
> +	unsigned int num_cw = nandc->max_cwperpage;
> +	void *bam_txn_buf;
> +
> +	bam_txn_size =
> +		sizeof(*bam_txn) + num_cw *
> +		((sizeof(*bam_txn->bam_ce) * QPIC_PER_CW_CMD_ELEMENTS) +
> +		(sizeof(*bam_txn->cmd_sgl) * QPIC_PER_CW_CMD_SGL) +
> +		(sizeof(*bam_txn->data_sgl) * QPIC_PER_CW_DATA_SGL));
> +
> +	bam_txn_buf = devm_kzalloc(nandc->dev, bam_txn_size, GFP_KERNEL);
> +	if (!bam_txn_buf)
> +		return NULL;
> +
> +	bam_txn = bam_txn_buf;
> +	bam_txn_buf += sizeof(*bam_txn);
> +
> +	bam_txn->bam_ce = bam_txn_buf;
> +	bam_txn_buf +=
> +		sizeof(*bam_txn->bam_ce) * QPIC_PER_CW_CMD_ELEMENTS * num_cw;
> +
> +	bam_txn->cmd_sgl = bam_txn_buf;
> +	bam_txn_buf +=
> +		sizeof(*bam_txn->cmd_sgl) * QPIC_PER_CW_CMD_SGL * num_cw;
> +
> +	bam_txn->data_sgl = bam_txn_buf;
> +
> +	init_completion(&bam_txn->txn_done);
> +
> +	return bam_txn;
> +}
> +EXPORT_SYMBOL(alloc_bam_transaction);
> +
> +/* Clears the BAM transaction indexes */
> +void clear_bam_transaction(struct qcom_nand_controller *nandc)
> +{
> +	struct bam_transaction *bam_txn = nandc->bam_txn;
> +
> +	if (!nandc->props->is_bam)
> +		return;
> +
> +	bam_txn->bam_ce_pos = 0;
> +	bam_txn->bam_ce_start = 0;
> +	bam_txn->cmd_sgl_pos = 0;
> +	bam_txn->cmd_sgl_start = 0;
> +	bam_txn->tx_sgl_pos = 0;
> +	bam_txn->tx_sgl_start = 0;
> +	bam_txn->rx_sgl_pos = 0;
> +	bam_txn->rx_sgl_start = 0;
> +	bam_txn->last_data_desc = NULL;
> +	bam_txn->wait_second_completion = false;
> +
> +	sg_init_table(bam_txn->cmd_sgl, nandc->max_cwperpage *
> +		      QPIC_PER_CW_CMD_SGL);
> +	sg_init_table(bam_txn->data_sgl, nandc->max_cwperpage *
> +		      QPIC_PER_CW_DATA_SGL);
> +
> +	reinit_completion(&bam_txn->txn_done);
> +}
> +EXPORT_SYMBOL(clear_bam_transaction);
> +
> +/* one time setup of a few nand controller registers */

Does this needs to be shared?

> +int qcom_nandc_setup(struct qcom_nand_controller *nandc)
> +{
> +	u32 nand_ctrl;
> +
> +	/* kill onenand */
> +	if (!nandc->props->is_qpic)
> +		nandc_write(nandc, SFLASHC_BURST_CFG, 0);
> +
> +	if (!nandc->props->qpic_v2)
> +		nandc_write(nandc, dev_cmd_reg_addr(nandc, NAND_DEV_CMD_VLD),
> +			    NAND_DEV_CMD_VLD_VAL);
> +
> +	/* enable ADM or BAM DMA */
> +	if (nandc->props->is_bam) {
> +		nand_ctrl = nandc_read(nandc, NAND_CTRL);
> +
> +		/*
> +		 *NAND_CTRL is an operational registers, and CPU
> +		 * access to operational registers are read only
> +		 * in BAM mode. So update the NAND_CTRL register
> +		 * only if it is not in BAM mode. In most cases BAM
> +		 * mode will be enabled in bootloader
> +		 */
> +		if (!(nand_ctrl & BAM_MODE_EN))
> +			nandc_write(nandc, NAND_CTRL, nand_ctrl | BAM_MODE_EN);
> +	} else {
> +		nandc_write(nandc, NAND_FLASH_CHIP_SELECT, DM_EN);
> +	}
> +
> +	/* save the original values of these registers */
> +	if (!nandc->props->qpic_v2) {
> +		nandc->cmd1 = nandc_read(nandc, dev_cmd_reg_addr(nandc, NAND_DEV_CMD1));
> +		nandc->vld = NAND_DEV_CMD_VLD_VAL;
> +	}
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(qcom_nandc_setup);
> +
> +void qcom_nandc_unalloc(struct qcom_nand_controller *nandc)
> +{
> +	if (nandc->props->is_bam) {
> +		if (!dma_mapping_error(nandc->dev, nandc->reg_read_dma))
> +			dma_unmap_single(nandc->dev, nandc->reg_read_dma,
> +					 MAX_REG_RD *
> +					 sizeof(*nandc->reg_read_buf),
> +					 DMA_FROM_DEVICE);
> +
> +		if (nandc->tx_chan)
> +			dma_release_channel(nandc->tx_chan);
> +
> +		if (nandc->rx_chan)
> +			dma_release_channel(nandc->rx_chan);
> +
> +		if (nandc->cmd_chan)
> +			dma_release_channel(nandc->cmd_chan);
> +	} else {
> +		if (nandc->chan)
> +			dma_release_channel(nandc->chan);
> +	}
> +}
> +EXPORT_SYMBOL(qcom_nandc_unalloc);
> +
> +int qcom_nandc_alloc(struct qcom_nand_controller *nandc)
> +{
> +	int ret;
> +
> +	ret = dma_set_coherent_mask(nandc->dev, DMA_BIT_MASK(32));
> +	if (ret) {
> +		dev_err(nandc->dev, "failed to set DMA mask\n");
> +		return ret;
> +	}
> +
> +	/*
> +	 * we use the internal buffer for reading ONFI params, reading small
> +	 * data like ID and status, and preforming read-copy-write operations

performing

Please run checkpatch.pl, I believe the tool should catch these.

> +	 * when writing to a codeword partially. 532 is the maximum possible
> +	 * size of a codeword for our nand controller
> +	 */
> +	nandc->buf_size = 532;
> +
> +	nandc->data_buffer = devm_kzalloc(nandc->dev, nandc->buf_size,
> +					GFP_KERNEL);
> +	if (!nandc->data_buffer)
> +		return -ENOMEM;
> +
> +	nandc->regs = devm_kzalloc(nandc->dev, sizeof(*nandc->regs),
> +					GFP_KERNEL);
> +	if (!nandc->regs)
> +		return -ENOMEM;
> +
> +	nandc->reg_read_buf = devm_kcalloc(nandc->dev,
> +				MAX_REG_RD, sizeof(*nandc->reg_read_buf),
> +				GFP_KERNEL);
> +	if (!nandc->reg_read_buf)
> +		return -ENOMEM;
> +
> +	if (nandc->props->is_bam) {

It's probably the 10th time I ask, but what the heck is this is_bam
parameter showing? It looks like you're handling two different
controllers in the same driver without using different compatibles.

> +		nandc->reg_read_dma =
> +			dma_map_single(nandc->dev, nandc->reg_read_buf,
> +				       MAX_REG_RD *
> +				       sizeof(*nandc->reg_read_buf),
> +				       DMA_FROM_DEVICE);
> +		if (dma_mapping_error(nandc->dev, nandc->reg_read_dma)) {
> +			dev_err(nandc->dev, "failed to DMA MAP reg buffer\n");
> +			return -EIO;
> +		}
> +
> +		nandc->tx_chan = dma_request_chan(nandc->dev, "tx");
> +		if (IS_ERR(nandc->tx_chan)) {
> +			ret = PTR_ERR(nandc->tx_chan);
> +			nandc->tx_chan = NULL;
> +			dev_err_probe(nandc->dev, ret,
> +				      "tx DMA channel request failed\n");
> +			goto unalloc;
> +		}
> +
> +		nandc->rx_chan = dma_request_chan(nandc->dev, "rx");
> +		if (IS_ERR(nandc->rx_chan)) {
> +			ret = PTR_ERR(nandc->rx_chan);
> +			nandc->rx_chan = NULL;
> +			dev_err_probe(nandc->dev, ret,
> +				      "rx DMA channel request failed\n");
> +			goto unalloc;
> +		}
> +
> +		nandc->cmd_chan = dma_request_chan(nandc->dev, "cmd");
> +		if (IS_ERR(nandc->cmd_chan)) {
> +			ret = PTR_ERR(nandc->cmd_chan);
> +			nandc->cmd_chan = NULL;
> +			dev_err_probe(nandc->dev, ret,
> +				      "cmd DMA channel request failed\n");
> +			goto unalloc;
> +		}
> +
> +		/*
> +		 * Initially allocate BAM transaction to read ONFI param page.
> +		 * After detecting all the devices, this BAM transaction will
> +		 * be freed and the next BAM tranasction will be allocated with

Typo

> +		 * maximum codeword size
> +		 */
> +		nandc->max_cwperpage = 1;
> +		nandc->bam_txn = alloc_bam_transaction(nandc);
> +		if (!nandc->bam_txn) {
> +			dev_err(nandc->dev,
> +				"failed to allocate bam transaction\n");
> +			ret = -ENOMEM;
> +			goto unalloc;
> +		}
> +	} else {
> +		nandc->chan = dma_request_chan(nandc->dev, "rxtx");
> +		if (IS_ERR(nandc->chan)) {
> +			ret = PTR_ERR(nandc->chan);
> +			nandc->chan = NULL;
> +			dev_err_probe(nandc->dev, ret,
> +				      "rxtx DMA channel request failed\n");
> +			return ret;
> +		}
> +	}
> +
> +	INIT_LIST_HEAD(&nandc->desc_list);
> +	INIT_LIST_HEAD(&nandc->host_list);
> +
> +	return 0;
> +unalloc:
> +	qcom_nandc_unalloc(nandc);
> +	return ret;
> +}
> +EXPORT_SYMBOL(qcom_nandc_alloc);
> diff --git a/include/linux/mtd/nand-qpic-common.h b/include/linux/mtd/nand-qpic-common.h
> new file mode 100644
> index 000000000000..c461c1781330
> --- /dev/null
> +++ b/include/linux/mtd/nand-qpic-common.h

...

> +	u32 cmd1, vld;
> +	bool exec_opwrite;
> +};
> +
> +/*
> + * NAND chip structure

qcom_nand_host is a nand chip structure?

> + *
> + * @boot_partitions:		array of boot partitions where offset and size of the
> + *				boot partitions are stored
> + *
> + * @chip:			base NAND chip structure
> + * @node:			list node to add itself to host_list in
> + *				qcom_nand_controller
> + *
> + * @nr_boot_partitions:		count of the boot partitions where spare data is not
> + *				protected by ECC
> + *
> + * @cs:				chip select value for this chip
> + * @cw_size:			the number of bytes in a single step/codeword
> + *				of a page, consisting of all data, ecc, spare
> + *				and reserved bytes
> + * @cw_data:			the number of bytes within a codeword protected
> + *				by ECC
> + * @ecc_bytes_hw:		ECC bytes used by controller hardware for this
> + *				chip
> + *
> + * @last_command:		keeps track of last command on this chip. used
> + *				for reading correct status
> + *
> + * @cfg0, cfg1, cfg0_raw..:	NANDc register configurations needed for
> + *				ecc/non-ecc mode for the current nand flash
> + *				device
> + *
> + * @status:			value to be returned if NAND_CMD_STATUS command
> + *				is executed
> + * @codeword_fixup:		keep track of the current layout used by
> + *				the driver for read/write operation.
> + * @use_ecc:			request the controller to use ECC for the
> + *				upcoming read/write
> + * @bch_enabled:		flag to tell whether BCH ECC mode is used
> + */
> +struct qcom_nand_host {
> +	struct qcom_nand_boot_partition *boot_partitions;
> +
> +	struct nand_chip chip;
> +	struct list_head node;
> +
> +	int nr_boot_partitions;
> +
> +	int cs;
> +	int cw_size;
> +	int cw_data;
> +	int ecc_bytes_hw;
> +	int spare_bytes;
> +	int bbm_size;
> +
> +	int last_command;
> +
> +	u32 cfg0, cfg1;
> +	u32 cfg0_raw, cfg1_raw;
> +	u32 ecc_buf_cfg;
> +	u32 ecc_bch_cfg;
> +	u32 clrflashstatus;
> +	u32 clrreadstatus;
> +
> +	u8 status;
> +	bool codeword_fixup;
> +	bool use_ecc;
> +	bool bch_enabled;
> +};
> +

I would like to see how useful are all these exports. I believe the
current NAND controller driver already has some of these functions
defined, could you please move the functions rather than adding them
here without removing them in the other driver?

Thanks, Miquèl
  

Patch

diff --git a/drivers/mtd/nand/qpic_common.c b/drivers/mtd/nand/qpic_common.c
new file mode 100644
index 000000000000..983768a1ea94
--- /dev/null
+++ b/drivers/mtd/nand/qpic_common.c
@@ -0,0 +1,840 @@ 
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * QPIC common API file.
+ * Copyright (C) 2023  Qualcomm Inc.
+ * Authors:	Md sadre Alam		<quic_mdalam@quicinc.com>
+ *		Sricharan R		<quic_srichara@quicinc.com>
+ */
+
+#include <linux/mtd/nand-qpic-common.h>
+
+/* Frees the BAM transaction memory */
+void free_bam_transaction(struct qcom_nand_controller *nandc)
+{
+	struct bam_transaction *bam_txn = nandc->bam_txn;
+
+	devm_kfree(nandc->dev, bam_txn);
+}
+EXPORT_SYMBOL(free_bam_transaction);
+
+/* Callback for DMA descriptor completion */
+void qpic_bam_dma_done(void *data)
+{
+	struct bam_transaction *bam_txn = data;
+
+	/*
+	 * In case of data transfer with NAND, 2 callbacks will be generated.
+	 * One for command channel and another one for data channel.
+	 * If current transaction has data descriptors
+	 * (i.e. wait_second_completion is true), then set this to false
+	 * and wait for second DMA descriptor completion.
+	 */
+	if (bam_txn->wait_second_completion)
+		bam_txn->wait_second_completion = false;
+	else
+		complete(&bam_txn->txn_done);
+}
+EXPORT_SYMBOL(qpic_bam_dma_done);
+
+u32 nandc_read(struct qcom_nand_controller *nandc, int offset)
+{
+	return ioread32(nandc->base + offset);
+}
+EXPORT_SYMBOL(nandc_read);
+
+void nandc_write(struct qcom_nand_controller *nandc, int offset,
+			       u32 val)
+{
+	iowrite32(val, nandc->base + offset);
+}
+EXPORT_SYMBOL(nandc_write);
+
+void nandc_read_buffer_sync(struct qcom_nand_controller *nandc,
+					  bool is_cpu)
+{
+	if (!nandc->props->is_bam)
+		return;
+
+	if (is_cpu)
+		dma_sync_single_for_cpu(nandc->dev, nandc->reg_read_dma,
+					MAX_REG_RD *
+					sizeof(*nandc->reg_read_buf),
+					DMA_FROM_DEVICE);
+	else
+		dma_sync_single_for_device(nandc->dev, nandc->reg_read_dma,
+					   MAX_REG_RD *
+					   sizeof(*nandc->reg_read_buf),
+					   DMA_FROM_DEVICE);
+}
+EXPORT_SYMBOL(nandc_read_buffer_sync);
+
+__le32 *offset_to_nandc_reg(struct nandc_regs *regs, int offset)
+{
+	switch (offset) {
+	case NAND_FLASH_CMD:
+		return &regs->cmd;
+	case NAND_ADDR0:
+		return &regs->addr0;
+	case NAND_ADDR1:
+		return &regs->addr1;
+	case NAND_FLASH_CHIP_SELECT:
+		return &regs->chip_sel;
+	case NAND_EXEC_CMD:
+		return &regs->exec;
+	case NAND_FLASH_STATUS:
+		return &regs->clrflashstatus;
+	case NAND_DEV0_CFG0:
+		return &regs->cfg0;
+	case NAND_DEV0_CFG1:
+		return &regs->cfg1;
+	case NAND_DEV0_ECC_CFG:
+		return &regs->ecc_bch_cfg;
+	case NAND_READ_STATUS:
+		return &regs->clrreadstatus;
+	case NAND_DEV_CMD1:
+		return &regs->cmd1;
+	case NAND_DEV_CMD1_RESTORE:
+		return &regs->orig_cmd1;
+	case NAND_DEV_CMD_VLD:
+		return &regs->vld;
+	case NAND_DEV_CMD_VLD_RESTORE:
+		return &regs->orig_vld;
+	case NAND_EBI2_ECC_BUF_CFG:
+		return &regs->ecc_buf_cfg;
+	case NAND_READ_LOCATION_0:
+		return &regs->read_location0;
+	case NAND_READ_LOCATION_1:
+		return &regs->read_location1;
+	case NAND_READ_LOCATION_2:
+		return &regs->read_location2;
+	case NAND_READ_LOCATION_3:
+		return &regs->read_location3;
+	case NAND_READ_LOCATION_LAST_CW_0:
+		return &regs->read_location_last0;
+	case NAND_READ_LOCATION_LAST_CW_1:
+		return &regs->read_location_last1;
+	case NAND_READ_LOCATION_LAST_CW_2:
+		return &regs->read_location_last2;
+	case NAND_READ_LOCATION_LAST_CW_3:
+		return &regs->read_location_last3;
+	case NAND_FLASH_SPI_CFG:
+		return &regs->spi_cfg;
+	case NAND_NUM_ADDR_CYCLES:
+		return &regs->num_addr_cycle;
+	case NAND_BUSY_CHECK_WAIT_CNT:
+		return &regs->busy_wait_cnt;
+	case NAND_MSTR_CONFIG:
+		return &regs->mstr_cfg;
+	case NAND_FLASH_FEATURES:
+		return &regs->flash_feature;
+	default:
+		return NULL;
+	}
+}
+EXPORT_SYMBOL(offset_to_nandc_reg);
+
+/* reset the register read buffer for next NAND operation */
+void clear_read_regs(struct qcom_nand_controller *nandc)
+{
+	nandc->reg_read_pos = 0;
+	nandc_read_buffer_sync(nandc, false);
+}
+EXPORT_SYMBOL(clear_read_regs);
+
+int prep_adm_dma_desc(struct qcom_nand_controller *nandc, bool read,
+			     int reg_off, const void *vaddr, int size,
+			     bool flow_control)
+{
+	struct desc_info *desc;
+	struct dma_async_tx_descriptor *dma_desc;
+	struct scatterlist *sgl;
+	struct dma_slave_config slave_conf;
+	struct qcom_adm_peripheral_config periph_conf = {};
+	enum dma_transfer_direction dir_eng;
+	int ret;
+
+	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
+	if (!desc)
+		return -ENOMEM;
+
+	sgl = &desc->adm_sgl;
+
+	sg_init_one(sgl, vaddr, size);
+
+	if (read) {
+		dir_eng = DMA_DEV_TO_MEM;
+		desc->dir = DMA_FROM_DEVICE;
+	} else {
+		dir_eng = DMA_MEM_TO_DEV;
+		desc->dir = DMA_TO_DEVICE;
+	}
+
+	ret = dma_map_sg(nandc->dev, sgl, 1, desc->dir);
+	if (ret == 0) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	memset(&slave_conf, 0x00, sizeof(slave_conf));
+
+	slave_conf.device_fc = flow_control;
+	if (read) {
+		slave_conf.src_maxburst = 16;
+		slave_conf.src_addr = nandc->base_dma + reg_off;
+		if (nandc->data_crci) {
+			periph_conf.crci = nandc->data_crci;
+			slave_conf.peripheral_config = &periph_conf;
+			slave_conf.peripheral_size = sizeof(periph_conf);
+		}
+	} else {
+		slave_conf.dst_maxburst = 16;
+		slave_conf.dst_addr = nandc->base_dma + reg_off;
+		if (nandc->cmd_crci) {
+			periph_conf.crci = nandc->cmd_crci;
+			slave_conf.peripheral_config = &periph_conf;
+			slave_conf.peripheral_size = sizeof(periph_conf);
+		}
+	}
+
+	ret = dmaengine_slave_config(nandc->chan, &slave_conf);
+	if (ret) {
+		dev_err(nandc->dev, "failed to configure dma channel\n");
+		goto err;
+	}
+
+	dma_desc = dmaengine_prep_slave_sg(nandc->chan, sgl, 1, dir_eng, 0);
+	if (!dma_desc) {
+		dev_err(nandc->dev, "failed to prepare desc\n");
+		ret = -EINVAL;
+		goto err;
+	}
+
+	desc->dma_desc = dma_desc;
+
+	list_add_tail(&desc->node, &nandc->desc_list);
+
+	return 0;
+err:
+	kfree(desc);
+
+	return ret;
+}
+
+/* helpers to submit/free our list of dma descriptors */
+int submit_descs(struct qcom_nand_controller *nandc)
+{
+	struct desc_info *desc;
+	dma_cookie_t cookie = 0;
+	struct bam_transaction *bam_txn = nandc->bam_txn;
+	int r;
+
+	if (nandc->props->is_bam) {
+		if (bam_txn->rx_sgl_pos > bam_txn->rx_sgl_start) {
+			r = prepare_bam_async_desc(nandc, nandc->rx_chan, 0);
+			if (r)
+				return r;
+		}
+
+		if (bam_txn->tx_sgl_pos > bam_txn->tx_sgl_start) {
+			r = prepare_bam_async_desc(nandc, nandc->tx_chan,
+						   DMA_PREP_INTERRUPT);
+			if (r)
+				return r;
+		}
+
+		if (bam_txn->cmd_sgl_pos > bam_txn->cmd_sgl_start) {
+			r = prepare_bam_async_desc(nandc, nandc->cmd_chan,
+						   DMA_PREP_CMD);
+			if (r)
+				return r;
+		}
+	}
+
+	list_for_each_entry(desc, &nandc->desc_list, node)
+		cookie = dmaengine_submit(desc->dma_desc);
+
+	if (nandc->props->is_bam) {
+		bam_txn->last_cmd_desc->callback = qpic_bam_dma_done;
+		bam_txn->last_cmd_desc->callback_param = bam_txn;
+		if (bam_txn->last_data_desc) {
+			bam_txn->last_data_desc->callback = qpic_bam_dma_done;
+			bam_txn->last_data_desc->callback_param = bam_txn;
+			bam_txn->wait_second_completion = true;
+		}
+
+		dma_async_issue_pending(nandc->tx_chan);
+		dma_async_issue_pending(nandc->rx_chan);
+		dma_async_issue_pending(nandc->cmd_chan);
+
+		if (!wait_for_completion_timeout(&bam_txn->txn_done,
+						 QPIC_NAND_COMPLETION_TIMEOUT))
+			return -ETIMEDOUT;
+	} else {
+		if (dma_sync_wait(nandc->chan, cookie) != DMA_COMPLETE)
+			return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(submit_descs);
+
+void free_descs(struct qcom_nand_controller *nandc)
+{
+	struct desc_info *desc, *n;
+
+	list_for_each_entry_safe(desc, n, &nandc->desc_list, node) {
+		list_del(&desc->node);
+
+		if (nandc->props->is_bam)
+			dma_unmap_sg(nandc->dev, desc->bam_sgl,
+				     desc->sgl_cnt, desc->dir);
+		else
+			dma_unmap_sg(nandc->dev, &desc->adm_sgl, 1,
+				     desc->dir);
+
+		kfree(desc);
+	}
+}
+EXPORT_SYMBOL(free_descs);
+
+/*
+ * Maps the scatter gather list for DMA transfer and forms the DMA descriptor
+ * for BAM. This descriptor will be added in the NAND DMA descriptor queue
+ * which will be submitted to DMA engine.
+ */
+int prepare_bam_async_desc(struct qcom_nand_controller *nandc,
+				  struct dma_chan *chan,
+				  unsigned long flags)
+{
+	struct desc_info *desc;
+	struct scatterlist *sgl;
+	unsigned int sgl_cnt;
+	int ret;
+	struct bam_transaction *bam_txn = nandc->bam_txn;
+	enum dma_transfer_direction dir_eng;
+	struct dma_async_tx_descriptor *dma_desc;
+
+	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
+	if (!desc)
+		return -ENOMEM;
+
+	if (chan == nandc->cmd_chan) {
+		sgl = &bam_txn->cmd_sgl[bam_txn->cmd_sgl_start];
+		sgl_cnt = bam_txn->cmd_sgl_pos - bam_txn->cmd_sgl_start;
+		bam_txn->cmd_sgl_start = bam_txn->cmd_sgl_pos;
+		dir_eng = DMA_MEM_TO_DEV;
+		desc->dir = DMA_TO_DEVICE;
+	} else if (chan == nandc->tx_chan) {
+		sgl = &bam_txn->data_sgl[bam_txn->tx_sgl_start];
+		sgl_cnt = bam_txn->tx_sgl_pos - bam_txn->tx_sgl_start;
+		bam_txn->tx_sgl_start = bam_txn->tx_sgl_pos;
+		dir_eng = DMA_MEM_TO_DEV;
+		desc->dir = DMA_TO_DEVICE;
+	} else {
+		sgl = &bam_txn->data_sgl[bam_txn->rx_sgl_start];
+		sgl_cnt = bam_txn->rx_sgl_pos - bam_txn->rx_sgl_start;
+		bam_txn->rx_sgl_start = bam_txn->rx_sgl_pos;
+		dir_eng = DMA_DEV_TO_MEM;
+		desc->dir = DMA_FROM_DEVICE;
+	}
+
+	sg_mark_end(sgl + sgl_cnt - 1);
+	ret = dma_map_sg(nandc->dev, sgl, sgl_cnt, desc->dir);
+	if (ret == 0) {
+		dev_err(nandc->dev, "failure in mapping desc\n");
+		kfree(desc);
+		return -ENOMEM;
+	}
+
+	desc->sgl_cnt = sgl_cnt;
+	desc->bam_sgl = sgl;
+
+	dma_desc = dmaengine_prep_slave_sg(chan, sgl, sgl_cnt, dir_eng,
+					   flags);
+
+	if (!dma_desc) {
+		dev_err(nandc->dev, "failure in prep desc\n");
+		dma_unmap_sg(nandc->dev, sgl, sgl_cnt, desc->dir);
+		kfree(desc);
+		return -EINVAL;
+	}
+
+	desc->dma_desc = dma_desc;
+
+	/* update last data/command descriptor */
+	if (chan == nandc->cmd_chan)
+		bam_txn->last_cmd_desc = dma_desc;
+	else
+		bam_txn->last_data_desc = dma_desc;
+
+	list_add_tail(&desc->node, &nandc->desc_list);
+
+	return 0;
+}
+EXPORT_SYMBOL(prepare_bam_async_desc);
+
+/*
+ * Prepares the command descriptor for BAM DMA which will be used for NAND
+ * register reads and writes. The command descriptor requires the command
+ * to be formed in command element type so this function uses the command
+ * element from bam transaction ce array and fills the same with required
+ * data. A single SGL can contain multiple command elements so
+ * NAND_BAM_NEXT_SGL will be used for starting the separate SGL
+ * after the current command element.
+ */
+int prep_bam_dma_desc_cmd(struct qcom_nand_controller *nandc, bool read,
+				 int reg_off, const void *vaddr,
+				 int size, unsigned int flags)
+{
+	int bam_ce_size;
+	int i, ret;
+	struct bam_cmd_element *bam_ce_buffer;
+	struct bam_transaction *bam_txn = nandc->bam_txn;
+
+	bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_pos];
+
+	/* fill the command desc */
+	for (i = 0; i < size; i++) {
+		if (read)
+			bam_prep_ce(&bam_ce_buffer[i],
+				    nandc_reg_phys(nandc, reg_off + 4 * i),
+				    BAM_READ_COMMAND,
+				    reg_buf_dma_addr(nandc,
+						     (__le32 *)vaddr + i));
+		else
+			bam_prep_ce_le32(&bam_ce_buffer[i],
+					 nandc_reg_phys(nandc, reg_off + 4 * i),
+					 BAM_WRITE_COMMAND,
+					 *((__le32 *)vaddr + i));
+	}
+
+	bam_txn->bam_ce_pos += size;
+
+	/* use the separate sgl after this command */
+	if (flags & NAND_BAM_NEXT_SGL) {
+		bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_start];
+		bam_ce_size = (bam_txn->bam_ce_pos -
+				bam_txn->bam_ce_start) *
+				sizeof(struct bam_cmd_element);
+		sg_set_buf(&bam_txn->cmd_sgl[bam_txn->cmd_sgl_pos],
+			   bam_ce_buffer, bam_ce_size);
+		bam_txn->cmd_sgl_pos++;
+		bam_txn->bam_ce_start = bam_txn->bam_ce_pos;
+
+		if (flags & NAND_BAM_NWD) {
+			ret = prepare_bam_async_desc(nandc, nandc->cmd_chan,
+						     DMA_PREP_FENCE |
+						     DMA_PREP_CMD);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(prep_bam_dma_desc_cmd);
+
+/*
+ * Prepares the data descriptor for BAM DMA which will be used for NAND
+ * data reads and writes.
+ */
+int prep_bam_dma_desc_data(struct qcom_nand_controller *nandc, bool read,
+				  const void *vaddr,
+				  int size, unsigned int flags)
+{
+	int ret;
+	struct bam_transaction *bam_txn = nandc->bam_txn;
+
+	if (read) {
+		sg_set_buf(&bam_txn->data_sgl[bam_txn->rx_sgl_pos],
+			   vaddr, size);
+		bam_txn->rx_sgl_pos++;
+	} else {
+		sg_set_buf(&bam_txn->data_sgl[bam_txn->tx_sgl_pos],
+			   vaddr, size);
+		bam_txn->tx_sgl_pos++;
+
+		/*
+		 * BAM will only set EOT for DMA_PREP_INTERRUPT so if this flag
+		 * is not set, form the DMA descriptor
+		 */
+		if (!(flags & NAND_BAM_NO_EOT)) {
+			ret = prepare_bam_async_desc(nandc, nandc->tx_chan,
+						     DMA_PREP_INTERRUPT);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(prep_bam_dma_desc_data);
+
+/*
+ * read_reg_dma:	prepares a descriptor to read a given number of
+ *			contiguous registers to the reg_read_buf pointer
+ *
+ * @first:		offset of the first register in the contiguous block
+ * @num_regs:		number of registers to read
+ * @flags:		flags to control DMA descriptor preparation
+ */
+int read_reg_dma(struct qcom_nand_controller *nandc, int first,
+			int num_regs, unsigned int flags)
+{
+	bool flow_control = false;
+	void *vaddr;
+
+	vaddr = nandc->reg_read_buf + nandc->reg_read_pos;
+	nandc->reg_read_pos += num_regs;
+
+	if (first == NAND_DEV_CMD_VLD || first == NAND_DEV_CMD1)
+		first = dev_cmd_reg_addr(nandc, first);
+
+	if (nandc->props->is_bam)
+		return prep_bam_dma_desc_cmd(nandc, true, first, vaddr,
+					     num_regs, flags);
+
+	if (first == NAND_READ_ID || first == NAND_FLASH_STATUS)
+		flow_control = true;
+
+	return prep_adm_dma_desc(nandc, true, first, vaddr,
+				 num_regs * sizeof(u32), flow_control);
+}
+EXPORT_SYMBOL(read_reg_dma);
+
+/*
+ * write_reg_dma:	prepares a descriptor to write a given number of
+ *			contiguous registers
+ *
+ * @first:		offset of the first register in the contiguous block
+ * @num_regs:		number of registers to write
+ * @flags:		flags to control DMA descriptor preparation
+ */
+int write_reg_dma(struct qcom_nand_controller *nandc, int first,
+			 int num_regs, unsigned int flags)
+{
+	bool flow_control = false;
+	struct nandc_regs *regs = nandc->regs;
+	void *vaddr;
+
+	vaddr = offset_to_nandc_reg(regs, first);
+
+	if (first == NAND_ERASED_CW_DETECT_CFG) {
+		if (flags & NAND_ERASED_CW_SET)
+			vaddr = &regs->erased_cw_detect_cfg_set;
+		else
+			vaddr = &regs->erased_cw_detect_cfg_clr;
+	}
+
+	if (first == NAND_EXEC_CMD)
+		flags |= NAND_BAM_NWD;
+
+	if (first == NAND_FLASH_SPI_CFG || first == NAND_NUM_ADDR_CYCLES
+		|| first == NAND_BUSY_CHECK_WAIT_CNT
+		|| first == NAND_MSTR_CONFIG)
+		first = dev_cmd_reg_addr(nandc, first);
+
+	if (first == NAND_DEV_CMD1_RESTORE || first == NAND_DEV_CMD1)
+		first = dev_cmd_reg_addr(nandc, NAND_DEV_CMD1);
+
+	if (first == NAND_DEV_CMD_VLD_RESTORE || first == NAND_DEV_CMD_VLD)
+		first = dev_cmd_reg_addr(nandc, NAND_DEV_CMD_VLD);
+
+	if (nandc->props->is_bam)
+		return prep_bam_dma_desc_cmd(nandc, false, first, vaddr,
+					     num_regs, flags);
+
+	if (first == NAND_FLASH_CMD)
+		flow_control = true;
+
+	return prep_adm_dma_desc(nandc, false, first, vaddr,
+				 num_regs * sizeof(u32), flow_control);
+}
+EXPORT_SYMBOL(write_reg_dma);
+
+/*
+ * read_data_dma:	prepares a DMA descriptor to transfer data from the
+ *			controller's internal buffer to the buffer 'vaddr'
+ *
+ * @reg_off:		offset within the controller's data buffer
+ * @vaddr:		virtual address of the buffer we want to write to
+ * @size:		DMA transaction size in bytes
+ * @flags:		flags to control DMA descriptor preparation
+ */
+int read_data_dma(struct qcom_nand_controller *nandc, int reg_off,
+			 const u8 *vaddr, int size, unsigned int flags)
+{
+	if (nandc->props->is_bam)
+		return prep_bam_dma_desc_data(nandc, true, vaddr, size, flags);
+
+	return prep_adm_dma_desc(nandc, true, reg_off, vaddr, size, false);
+}
+EXPORT_SYMBOL(read_data_dma);
+
+/*
+ * write_data_dma:	prepares a DMA descriptor to transfer data from
+ *			'vaddr' to the controller's internal buffer
+ *
+ * @reg_off:		offset within the controller's data buffer
+ * @vaddr:		virtual address of the buffer we want to read from
+ * @size:		DMA transaction size in bytes
+ * @flags:		flags to control DMA descriptor preparation
+ */
+int write_data_dma(struct qcom_nand_controller *nandc, int reg_off,
+			  const u8 *vaddr, int size, unsigned int flags)
+{
+	if (nandc->props->is_bam)
+		return prep_bam_dma_desc_data(nandc, false, vaddr, size, flags);
+
+	return prep_adm_dma_desc(nandc, false, reg_off, vaddr, size, false);
+}
+EXPORT_SYMBOL(write_data_dma);
+
+void nandc_set_reg(struct qcom_nand_controller *nandc, int offset,
+			  u32 val)
+{
+	struct nandc_regs *regs = nandc->regs;
+	__le32 *reg;
+
+	reg = offset_to_nandc_reg(regs, offset);
+	if (reg)
+		*reg = cpu_to_le32(val);
+}
+EXPORT_SYMBOL(nandc_set_reg);
+
+/* Allocates and Initializes the BAM transaction */
+struct bam_transaction *
+alloc_bam_transaction(struct qcom_nand_controller *nandc)
+{
+	struct bam_transaction *bam_txn;
+	size_t bam_txn_size;
+	unsigned int num_cw = nandc->max_cwperpage;
+	void *bam_txn_buf;
+
+	bam_txn_size =
+		sizeof(*bam_txn) + num_cw *
+		((sizeof(*bam_txn->bam_ce) * QPIC_PER_CW_CMD_ELEMENTS) +
+		(sizeof(*bam_txn->cmd_sgl) * QPIC_PER_CW_CMD_SGL) +
+		(sizeof(*bam_txn->data_sgl) * QPIC_PER_CW_DATA_SGL));
+
+	bam_txn_buf = devm_kzalloc(nandc->dev, bam_txn_size, GFP_KERNEL);
+	if (!bam_txn_buf)
+		return NULL;
+
+	bam_txn = bam_txn_buf;
+	bam_txn_buf += sizeof(*bam_txn);
+
+	bam_txn->bam_ce = bam_txn_buf;
+	bam_txn_buf +=
+		sizeof(*bam_txn->bam_ce) * QPIC_PER_CW_CMD_ELEMENTS * num_cw;
+
+	bam_txn->cmd_sgl = bam_txn_buf;
+	bam_txn_buf +=
+		sizeof(*bam_txn->cmd_sgl) * QPIC_PER_CW_CMD_SGL * num_cw;
+
+	bam_txn->data_sgl = bam_txn_buf;
+
+	init_completion(&bam_txn->txn_done);
+
+	return bam_txn;
+}
+EXPORT_SYMBOL(alloc_bam_transaction);
+
+/* Clears the BAM transaction indexes */
+void clear_bam_transaction(struct qcom_nand_controller *nandc)
+{
+	struct bam_transaction *bam_txn = nandc->bam_txn;
+
+	if (!nandc->props->is_bam)
+		return;
+
+	bam_txn->bam_ce_pos = 0;
+	bam_txn->bam_ce_start = 0;
+	bam_txn->cmd_sgl_pos = 0;
+	bam_txn->cmd_sgl_start = 0;
+	bam_txn->tx_sgl_pos = 0;
+	bam_txn->tx_sgl_start = 0;
+	bam_txn->rx_sgl_pos = 0;
+	bam_txn->rx_sgl_start = 0;
+	bam_txn->last_data_desc = NULL;
+	bam_txn->wait_second_completion = false;
+
+	sg_init_table(bam_txn->cmd_sgl, nandc->max_cwperpage *
+		      QPIC_PER_CW_CMD_SGL);
+	sg_init_table(bam_txn->data_sgl, nandc->max_cwperpage *
+		      QPIC_PER_CW_DATA_SGL);
+
+	reinit_completion(&bam_txn->txn_done);
+}
+EXPORT_SYMBOL(clear_bam_transaction);
+
+/* one time setup of a few nand controller registers */
+int qcom_nandc_setup(struct qcom_nand_controller *nandc)
+{
+	u32 nand_ctrl;
+
+	/* kill onenand */
+	if (!nandc->props->is_qpic)
+		nandc_write(nandc, SFLASHC_BURST_CFG, 0);
+
+	if (!nandc->props->qpic_v2)
+		nandc_write(nandc, dev_cmd_reg_addr(nandc, NAND_DEV_CMD_VLD),
+			    NAND_DEV_CMD_VLD_VAL);
+
+	/* enable ADM or BAM DMA */
+	if (nandc->props->is_bam) {
+		nand_ctrl = nandc_read(nandc, NAND_CTRL);
+
+		/*
+		 *NAND_CTRL is an operational registers, and CPU
+		 * access to operational registers are read only
+		 * in BAM mode. So update the NAND_CTRL register
+		 * only if it is not in BAM mode. In most cases BAM
+		 * mode will be enabled in bootloader
+		 */
+		if (!(nand_ctrl & BAM_MODE_EN))
+			nandc_write(nandc, NAND_CTRL, nand_ctrl | BAM_MODE_EN);
+	} else {
+		nandc_write(nandc, NAND_FLASH_CHIP_SELECT, DM_EN);
+	}
+
+	/* save the original values of these registers */
+	if (!nandc->props->qpic_v2) {
+		nandc->cmd1 = nandc_read(nandc, dev_cmd_reg_addr(nandc, NAND_DEV_CMD1));
+		nandc->vld = NAND_DEV_CMD_VLD_VAL;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(qcom_nandc_setup);
+
+void qcom_nandc_unalloc(struct qcom_nand_controller *nandc)
+{
+	if (nandc->props->is_bam) {
+		if (!dma_mapping_error(nandc->dev, nandc->reg_read_dma))
+			dma_unmap_single(nandc->dev, nandc->reg_read_dma,
+					 MAX_REG_RD *
+					 sizeof(*nandc->reg_read_buf),
+					 DMA_FROM_DEVICE);
+
+		if (nandc->tx_chan)
+			dma_release_channel(nandc->tx_chan);
+
+		if (nandc->rx_chan)
+			dma_release_channel(nandc->rx_chan);
+
+		if (nandc->cmd_chan)
+			dma_release_channel(nandc->cmd_chan);
+	} else {
+		if (nandc->chan)
+			dma_release_channel(nandc->chan);
+	}
+}
+EXPORT_SYMBOL(qcom_nandc_unalloc);
+
+int qcom_nandc_alloc(struct qcom_nand_controller *nandc)
+{
+	int ret;
+
+	ret = dma_set_coherent_mask(nandc->dev, DMA_BIT_MASK(32));
+	if (ret) {
+		dev_err(nandc->dev, "failed to set DMA mask\n");
+		return ret;
+	}
+
+	/*
+	 * we use the internal buffer for reading ONFI params, reading small
+	 * data like ID and status, and preforming read-copy-write operations
+	 * when writing to a codeword partially. 532 is the maximum possible
+	 * size of a codeword for our nand controller
+	 */
+	nandc->buf_size = 532;
+
+	nandc->data_buffer = devm_kzalloc(nandc->dev, nandc->buf_size,
+					GFP_KERNEL);
+	if (!nandc->data_buffer)
+		return -ENOMEM;
+
+	nandc->regs = devm_kzalloc(nandc->dev, sizeof(*nandc->regs),
+					GFP_KERNEL);
+	if (!nandc->regs)
+		return -ENOMEM;
+
+	nandc->reg_read_buf = devm_kcalloc(nandc->dev,
+				MAX_REG_RD, sizeof(*nandc->reg_read_buf),
+				GFP_KERNEL);
+	if (!nandc->reg_read_buf)
+		return -ENOMEM;
+
+	if (nandc->props->is_bam) {
+		nandc->reg_read_dma =
+			dma_map_single(nandc->dev, nandc->reg_read_buf,
+				       MAX_REG_RD *
+				       sizeof(*nandc->reg_read_buf),
+				       DMA_FROM_DEVICE);
+		if (dma_mapping_error(nandc->dev, nandc->reg_read_dma)) {
+			dev_err(nandc->dev, "failed to DMA MAP reg buffer\n");
+			return -EIO;
+		}
+
+		nandc->tx_chan = dma_request_chan(nandc->dev, "tx");
+		if (IS_ERR(nandc->tx_chan)) {
+			ret = PTR_ERR(nandc->tx_chan);
+			nandc->tx_chan = NULL;
+			dev_err_probe(nandc->dev, ret,
+				      "tx DMA channel request failed\n");
+			goto unalloc;
+		}
+
+		nandc->rx_chan = dma_request_chan(nandc->dev, "rx");
+		if (IS_ERR(nandc->rx_chan)) {
+			ret = PTR_ERR(nandc->rx_chan);
+			nandc->rx_chan = NULL;
+			dev_err_probe(nandc->dev, ret,
+				      "rx DMA channel request failed\n");
+			goto unalloc;
+		}
+
+		nandc->cmd_chan = dma_request_chan(nandc->dev, "cmd");
+		if (IS_ERR(nandc->cmd_chan)) {
+			ret = PTR_ERR(nandc->cmd_chan);
+			nandc->cmd_chan = NULL;
+			dev_err_probe(nandc->dev, ret,
+				      "cmd DMA channel request failed\n");
+			goto unalloc;
+		}
+
+		/*
+		 * Initially allocate BAM transaction to read ONFI param page.
+		 * After detecting all the devices, this BAM transaction will
+		 * be freed and the next BAM tranasction will be allocated with
+		 * maximum codeword size
+		 */
+		nandc->max_cwperpage = 1;
+		nandc->bam_txn = alloc_bam_transaction(nandc);
+		if (!nandc->bam_txn) {
+			dev_err(nandc->dev,
+				"failed to allocate bam transaction\n");
+			ret = -ENOMEM;
+			goto unalloc;
+		}
+	} else {
+		nandc->chan = dma_request_chan(nandc->dev, "rxtx");
+		if (IS_ERR(nandc->chan)) {
+			ret = PTR_ERR(nandc->chan);
+			nandc->chan = NULL;
+			dev_err_probe(nandc->dev, ret,
+				      "rxtx DMA channel request failed\n");
+			return ret;
+		}
+	}
+
+	INIT_LIST_HEAD(&nandc->desc_list);
+	INIT_LIST_HEAD(&nandc->host_list);
+
+	return 0;
+unalloc:
+	qcom_nandc_unalloc(nandc);
+	return ret;
+}
+EXPORT_SYMBOL(qcom_nandc_alloc);
diff --git a/include/linux/mtd/nand-qpic-common.h b/include/linux/mtd/nand-qpic-common.h
new file mode 100644
index 000000000000..c461c1781330
--- /dev/null
+++ b/include/linux/mtd/nand-qpic-common.h
@@ -0,0 +1,641 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * QCOM QPIC common APIs
+ *
+ * Copyright (c) 2023 Qualcomm Inc.
+ * Authors:	Md Sadre Alam		<quic_mdalam@quicinc.com>
+ *		Sricharan R		<quic_srichara@quicinc.com>
+ */
+
+#ifndef __DRIVERS_MTD_NAND_QCOM_ECC_H__
+#define __DRIVERS_MTD_NAND_QCOM_ECC_H__
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <linux/bitops.h>
+#include <linux/dma/qcom_adm.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/delay.h>
+#include <linux/dma/qcom_bam_dma.h>
+#include <linux/mtd/rawnand.h>
+#include <linux/mtd/partitions.h>
+#include <linux/types.h>
+
+/* NANDc reg offsets */
+#define	NAND_FLASH_CMD			0x00
+#define	NAND_ADDR0			0x04
+#define	NAND_ADDR1			0x08
+#define	NAND_FLASH_CHIP_SELECT		0x0c
+#define	NAND_EXEC_CMD			0x10
+#define	NAND_FLASH_STATUS		0x14
+#define	NAND_BUFFER_STATUS		0x18
+#define	NAND_DEV0_CFG0			0x20
+#define	NAND_DEV0_CFG1			0x24
+#define	NAND_DEV0_ECC_CFG		0x28
+#define	NAND_AUTO_STATUS_EN		0x2c
+#define	NAND_DEV1_CFG0			0x30
+#define	NAND_DEV1_CFG1			0x34
+#define	NAND_READ_ID			0x40
+#define	NAND_READ_STATUS		0x44
+#define	NAND_DEV_CMD0			0xa0
+#define	NAND_DEV_CMD1			0xa4
+#define	NAND_DEV_CMD2			0xa8
+#define	NAND_DEV_CMD_VLD		0xac
+#define NAND_FLASH_SPI_CFG              0xc0
+#define NAND_NUM_ADDR_CYCLES        	0xc4
+#define NAND_BUSY_CHECK_WAIT_CNT    	0xc8
+#define	SFLASHC_BURST_CFG		0xe0
+#define	NAND_ERASED_CW_DETECT_CFG	0xe8
+#define	NAND_ERASED_CW_DETECT_STATUS	0xec
+#define	NAND_EBI2_ECC_BUF_CFG		0xf0
+#define	FLASH_BUF_ACC			0x100
+
+#define	NAND_CTRL			0xf00
+#define	NAND_VERSION			0xf08
+#define	NAND_READ_LOCATION_0		0xf20
+#define	NAND_READ_LOCATION_1		0xf24
+#define	NAND_READ_LOCATION_2		0xf28
+#define	NAND_READ_LOCATION_3		0xf2c
+#define	NAND_READ_LOCATION_LAST_CW_0	0xf40
+#define	NAND_READ_LOCATION_LAST_CW_1	0xf44
+#define	NAND_READ_LOCATION_LAST_CW_2	0xf48
+#define	NAND_READ_LOCATION_LAST_CW_3	0xf4c
+#define NAND_MSTR_CONFIG           	0xf60
+#define NAND_FLASH_FEATURES             0xf64
+
+/*
+ * the NAND controller performs reads/writes with ECC in 516 byte chunks.
+ * the driver calls the chunks 'step' or 'codeword' interchangeably
+ */
+#define	NANDC_STEP_SIZE			512
+
+/* dummy register offsets, used by write_reg_dma */
+#define	NAND_DEV_CMD1_RESTORE		0xdead
+#define	NAND_DEV_CMD_VLD_RESTORE	0xbeef
+
+/* NAND_FLASH_CMD bits */
+#define	PAGE_ACC			BIT(4)
+#define	LAST_PAGE			BIT(5)
+
+/* NAND_FLASH_CHIP_SELECT bits */
+#define	NAND_DEV_SEL			0
+#define	DM_EN				BIT(2)
+
+/* NAND_FLASH_STATUS bits */
+#define	FS_OP_ERR			BIT(4)
+#define	FS_READY_BSY_N			BIT(5)
+#define	FS_MPU_ERR			BIT(8)
+#define	FS_DEVICE_STS_ERR		BIT(16)
+#define	FS_DEVICE_WP			BIT(23)
+
+/* NAND_BUFFER_STATUS bits */
+#define	BS_UNCORRECTABLE_BIT		BIT(8)
+#define	BS_CORRECTABLE_ERR_MSK		0x1f
+
+/* NAND_DEVn_CFG0 bits */
+#define	DISABLE_STATUS_AFTER_WRITE	4
+#define	CW_PER_PAGE			6
+#define	UD_SIZE_BYTES			9
+#define	UD_SIZE_BYTES_MASK		GENMASK(18, 9)
+#define	ECC_PARITY_SIZE_BYTES_RS	19
+#define	SPARE_SIZE_BYTES		23
+#define	SPARE_SIZE_BYTES_MASK		GENMASK(26, 23)
+#define	NUM_ADDR_CYCLES			27
+#define	STATUS_BFR_READ			30
+#define	SET_RD_MODE_AFTER_STATUS	31
+
+/* NAND_DEVn_CFG0 bits */
+#define	DEV0_CFG1_ECC_DISABLE		0
+#define	WIDE_FLASH			1
+#define	NAND_RECOVERY_CYCLES		2
+#define	CS_ACTIVE_BSY			5
+#define	BAD_BLOCK_BYTE_NUM		6
+#define	BAD_BLOCK_IN_SPARE_AREA		16
+#define	WR_RD_BSY_GAP			17
+#define	ENABLE_BCH_ECC			27
+
+/* NAND_DEV0_ECC_CFG bits */
+#define	ECC_CFG_ECC_DISABLE		0
+#define	ECC_SW_RESET			1
+#define	ECC_MODE			4
+#define	ECC_PARITY_SIZE_BYTES_BCH	8
+#define	ECC_NUM_DATA_BYTES		16
+#define	ECC_NUM_DATA_BYTES_MASK		GENMASK(25, 16)
+#define	ECC_FORCE_CLK_OPEN		30
+
+/* NAND_DEV_CMD1 bits */
+#define	READ_ADDR			0
+
+/* NAND_DEV_CMD_VLD bits */
+#define	READ_START_VLD			BIT(0)
+#define	READ_STOP_VLD			BIT(1)
+#define	WRITE_START_VLD			BIT(2)
+#define	ERASE_START_VLD			BIT(3)
+#define	SEQ_READ_START_VLD		BIT(4)
+
+/* NAND_EBI2_ECC_BUF_CFG bits */
+#define	NUM_STEPS			0
+
+/* NAND_ERASED_CW_DETECT_CFG bits */
+#define	ERASED_CW_ECC_MASK		1
+#define	AUTO_DETECT_RES			0
+#define	MASK_ECC			(1 << ERASED_CW_ECC_MASK)
+#define	RESET_ERASED_DET		(1 << AUTO_DETECT_RES)
+#define	ACTIVE_ERASED_DET		(0 << AUTO_DETECT_RES)
+#define	CLR_ERASED_PAGE_DET		(RESET_ERASED_DET | MASK_ECC)
+#define	SET_ERASED_PAGE_DET		(ACTIVE_ERASED_DET | MASK_ECC)
+
+/* NAND_ERASED_CW_DETECT_STATUS bits */
+#define	PAGE_ALL_ERASED			BIT(7)
+#define	CODEWORD_ALL_ERASED		BIT(6)
+#define	PAGE_ERASED			BIT(5)
+#define	CODEWORD_ERASED			BIT(4)
+#define	ERASED_PAGE			(PAGE_ALL_ERASED | PAGE_ERASED)
+#define	ERASED_CW			(CODEWORD_ALL_ERASED | CODEWORD_ERASED)
+
+/* NAND_READ_LOCATION_n bits */
+#define READ_LOCATION_OFFSET		0
+#define READ_LOCATION_SIZE		16
+#define READ_LOCATION_LAST		31
+
+/* Version Mask */
+#define	NAND_VERSION_MAJOR_MASK		0xf0000000
+#define	NAND_VERSION_MAJOR_SHIFT	28
+#define	NAND_VERSION_MINOR_MASK		0x0fff0000
+#define	NAND_VERSION_MINOR_SHIFT	16
+
+/* NAND OP_CMDs */
+#define	OP_PAGE_READ			0x2
+#define	OP_PAGE_READ_WITH_ECC		0x3
+#define	OP_PAGE_READ_WITH_ECC_SPARE	0x4
+#define	OP_PAGE_READ_ONFI_READ		0x5
+#define	OP_PROGRAM_PAGE			0x6
+#define	OP_PAGE_PROGRAM_WITH_ECC	0x7
+#define	OP_PROGRAM_PAGE_SPARE		0x9
+#define	OP_BLOCK_ERASE			0xa
+#define	OP_CHECK_STATUS			0xc
+#define	OP_FETCH_ID			0xb
+#define	OP_RESET_DEVICE			0xd
+#define ACC_FEATURE			0xe
+
+/* Default Value for NAND_DEV_CMD_VLD */
+#define NAND_DEV_CMD_VLD_VAL		(READ_START_VLD | WRITE_START_VLD | \
+					 ERASE_START_VLD | SEQ_READ_START_VLD)
+/* NAND_CTRL bits */
+#define	BAM_MODE_EN			BIT(0)
+
+/*
+ * the largest page size we support is 8K, this will have 16 steps/codewords
+ * of 512 bytes each
+ */
+#define	MAX_NUM_STEPS			(SZ_8K / NANDC_STEP_SIZE)
+
+/* we read at most 3 registers per codeword scan */
+#define	MAX_REG_RD			(3 * MAX_NUM_STEPS)
+
+/* ECC modes supported by the controller */
+#define	ECC_NONE	BIT(0)
+#define	ECC_RS_4BIT	BIT(1)
+#define	ECC_BCH_4BIT	BIT(2)
+#define	ECC_BCH_8BIT	BIT(3)
+
+#define nandc_set_read_loc_first(chip, reg, cw_offset, read_size, is_last_read_loc)	\
+nandc_set_reg(chip, reg,			\
+	      ((cw_offset) << READ_LOCATION_OFFSET) |		\
+	      ((read_size) << READ_LOCATION_SIZE) |			\
+	      ((is_last_read_loc) << READ_LOCATION_LAST))
+
+#define nandc_set_read_loc_last(chip, reg, cw_offset, read_size, is_last_read_loc)	\
+nandc_set_reg(chip, reg,			\
+	      ((cw_offset) << READ_LOCATION_OFFSET) |		\
+	      ((read_size) << READ_LOCATION_SIZE) |			\
+	      ((is_last_read_loc) << READ_LOCATION_LAST))
+
+/*
+ * Returns the actual register address for all NAND_DEV_ registers
+ * (i.e. NAND_DEV_CMD0, NAND_DEV_CMD1, NAND_DEV_CMD2 and NAND_DEV_CMD_VLD)
+ */
+#define dev_cmd_reg_addr(nandc, reg) ((nandc)->props->dev_cmd_reg_start + (reg))
+
+/* Returns the NAND register physical address */
+#define nandc_reg_phys(chip, offset) ((chip)->base_phys + (offset))
+
+/* Returns the dma address for reg read buffer */
+#define reg_buf_dma_addr(chip, vaddr) \
+	((chip)->reg_read_dma + \
+	((uint8_t *)(vaddr) - (uint8_t *)(chip)->reg_read_buf))
+
+#define QPIC_PER_CW_CMD_ELEMENTS	32
+#define QPIC_PER_CW_CMD_SGL		32
+#define QPIC_PER_CW_DATA_SGL		8
+
+#define QPIC_NAND_COMPLETION_TIMEOUT	msecs_to_jiffies(2000)
+
+/*
+ * Flags used in DMA descriptor preparation helper functions
+ * (i.e. read_reg_dma/write_reg_dma/read_data_dma/write_data_dma)
+ */
+/* Don't set the EOT in current tx BAM sgl */
+#define NAND_BAM_NO_EOT			BIT(0)
+/* Set the NWD flag in current BAM sgl */
+#define NAND_BAM_NWD			BIT(1)
+/* Finish writing in the current BAM sgl and start writing in another BAM sgl */
+#define NAND_BAM_NEXT_SGL		BIT(2)
+/*
+ * Erased codeword status is being used two times in single transfer so this
+ * flag will determine the current value of erased codeword status register
+ */
+#define NAND_ERASED_CW_SET		BIT(4)
+
+#define MAX_ADDRESS_CYCLE		5
+
+struct qpic_ecc {
+	struct device *dev;
+	const struct qpic_ecc_caps *caps;
+	struct completion done;
+	struct mutex lock;
+	u32 sectors;
+	u8 *eccdata;
+	bool use_ecc;
+	u32 ecc_modes;
+	int ecc_bytes_hw;
+	int spare_bytes;
+	int bbm_size;
+	int ecc_mode;
+	int bytes;
+	int steps;
+	int step_size;
+	int strength;
+	bool bch_enabled;
+};
+
+
+struct device_node;
+struct qpic_ecc;
+
+struct qcom_ecc_stats {
+	u32 corrected;
+	u32 bitflips;
+	u32 failed;
+};
+
+struct qcom_ecc {
+	bool use_ecc;
+	u32 ecc_modes;
+	int ecc_bytes_hw;
+	int spare_bytes;
+	int bbm_size;
+	int ecc_mode;
+	int bytes;
+	int steps;
+	bool bch_enabled;
+};
+
+/*
+ * This data type corresponds to the BAM transaction which will be used for all
+ * NAND transfers.
+ * @bam_ce - the array of BAM command elements
+ * @cmd_sgl - sgl for NAND BAM command pipe
+ * @data_sgl - sgl for NAND BAM consumer/producer pipe
+ * @last_data_desc - last DMA desc in data channel (tx/rx).
+ * @last_cmd_desc - last DMA desc in command channel.
+ * @txn_done - completion for NAND transfer.
+ * @bam_ce_pos - the index in bam_ce which is available for next sgl
+ * @bam_ce_start - the index in bam_ce which marks the start position ce
+ *		   for current sgl. It will be used for size calculation
+ *		   for current sgl
+ * @cmd_sgl_pos - current index in command sgl.
+ * @cmd_sgl_start - start index in command sgl.
+ * @tx_sgl_pos - current index in data sgl for tx.
+ * @tx_sgl_start - start index in data sgl for tx.
+ * @rx_sgl_pos - current index in data sgl for rx.
+ * @rx_sgl_start - start index in data sgl for rx.
+ * @wait_second_completion - wait for second DMA desc completion before making
+ *			     the NAND transfer completion.
+ */
+struct bam_transaction {
+	struct bam_cmd_element *bam_ce;
+	struct scatterlist *cmd_sgl;
+	struct scatterlist *data_sgl;
+	struct dma_async_tx_descriptor *last_data_desc;
+	struct dma_async_tx_descriptor *last_cmd_desc;
+	struct completion txn_done;
+	u32 bam_ce_pos;
+	u32 bam_ce_start;
+	u32 cmd_sgl_pos;
+	u32 cmd_sgl_start;
+	u32 tx_sgl_pos;
+	u32 tx_sgl_start;
+	u32 rx_sgl_pos;
+	u32 rx_sgl_start;
+	bool wait_second_completion;
+};
+
+/*
+ * This data type corresponds to the nand dma descriptor
+ * @dma_desc - low level DMA engine descriptor
+ * @list - list for desc_info
+ *
+ * @adm_sgl - sgl which will be used for single sgl dma descriptor. Only used by
+ *	      ADM
+ * @bam_sgl - sgl which will be used for dma descriptor. Only used by BAM
+ * @sgl_cnt - number of SGL in bam_sgl. Only used by BAM
+ * @dir - DMA transfer direction
+ */
+struct desc_info {
+	struct dma_async_tx_descriptor *dma_desc;
+	struct list_head node;
+
+	union {
+		struct scatterlist adm_sgl;
+		struct {
+			struct scatterlist *bam_sgl;
+			int sgl_cnt;
+		};
+	};
+	enum dma_data_direction dir;
+};
+
+/*
+ * holds the current register values that we want to write. acts as a contiguous
+ * chunk of memory which we use to write the controller registers through DMA.
+ */
+struct nandc_regs {
+	__le32 cmd;
+	__le32 addr0;
+	__le32 addr1;
+	__le32 chip_sel;
+	__le32 exec;
+
+	__le32 cfg0;
+	__le32 cfg1;
+	__le32 ecc_bch_cfg;
+
+	__le32 clrflashstatus;
+	__le32 clrreadstatus;
+
+	__le32 cmd1;
+	__le32 vld;
+
+	__le32 orig_cmd1;
+	__le32 orig_vld;
+
+	__le32 ecc_buf_cfg;
+	__le32 read_location0;
+	__le32 read_location1;
+	__le32 read_location2;
+	__le32 read_location3;
+	__le32 read_location_last0;
+	__le32 read_location_last1;
+	__le32 read_location_last2;
+	__le32 read_location_last3;
+	__le32 flash_feature;
+	__le32 spi_cfg;
+	__le32 num_addr_cycle;
+	__le32 busy_wait_cnt;
+	__le32 mstr_cfg;
+
+	__le32 erased_cw_detect_cfg_clr;
+	__le32 erased_cw_detect_cfg_set;
+};
+
+/*
+ * This data type corresponds to the NAND controller properties which varies
+ * among different NAND controllers.
+ * @dev_cmd_reg_start - NAND_DEV_CMD_* registers starting offset
+ * @is_bam - whether NAND controller is using BAM
+ * @is_qpic - whether NAND CTRL is part of qpic IP
+ * @qpic_v2 - flag to indicate QPIC IP version 2
+ * @use_codeword_fixup - whether NAND has different layout for boot partitions
+ */
+struct qcom_nandc_props {
+	u32 dev_cmd_reg_start;
+	bool is_bam;
+	bool is_qpic;
+	bool qpic_v2;
+	bool use_codeword_fixup;
+};
+
+/*
+ * NAND controller data struct
+ *
+ * @dev:			parent device
+ *
+ * @base:			MMIO base
+ *
+ * @core_clk:			controller clock
+ * @aon_clk:			another controller clock
+ *
+ * @regs:			a contiguous chunk of memory for DMA register
+ *				writes. contains the register values to be
+ *				written to controller
+ *
+ * @props:			properties of current NAND controller,
+ *				initialized via DT match data
+ *
+ * @controller:			base controller structure
+ * @host_list:			list containing all the chips attached to the
+ *				controller
+ *
+ * @chan:			dma channel
+ * @cmd_crci:			ADM DMA CRCI for command flow control
+ * @data_crci:			ADM DMA CRCI for data flow control
+ *
+ * @desc_list:			DMA descriptor list (list of desc_infos)
+ *
+ * @data_buffer:		our local DMA buffer for page read/writes,
+ *				used when we can't use the buffer provided
+ *				by upper layers directly
+ * @reg_read_buf:		local buffer for reading back registers via DMA
+ *
+ * @base_phys:			physical base address of controller registers
+ * @base_dma:			dma base address of controller registers
+ * @reg_read_dma:		contains dma address for register read buffer
+ *
+ * @buf_size/count/start:	markers for chip->legacy.read_buf/write_buf
+ *				functions
+ * @max_cwperpage:		maximum QPIC codewords required. calculated
+ *				from all connected NAND devices pagesize
+ *
+ * @reg_read_pos:		marker for data read in reg_read_buf
+ *
+ * @cmd1/vld:			some fixed controller register values
+ *
+ * @exec_opwrite:		flag to select correct number of code word
+ *				while reading status
+ */
+struct qcom_nand_controller {
+	struct spi_controller *ctlr;
+	struct device *dev;
+
+	void __iomem *base;
+
+	struct clk *core_clk;
+	struct clk *aon_clk;
+	struct clk *iomacro_clk;
+
+	struct nandc_regs *regs;
+	struct bam_transaction *bam_txn;
+
+	const struct qcom_nandc_props *props;
+
+	struct nand_controller controller;
+	struct list_head host_list;
+
+	union {
+		/* will be used only by QPIC for BAM DMA */
+		struct {
+			struct dma_chan *tx_chan;
+			struct dma_chan *rx_chan;
+			struct dma_chan *cmd_chan;
+		};
+
+		/* will be used only by EBI2 for ADM DMA */
+		struct {
+			struct dma_chan *chan;
+			unsigned int cmd_crci;
+			unsigned int data_crci;
+		};
+	};
+
+	struct list_head desc_list;
+
+	u8		*data_buffer;
+	__le32		*reg_read_buf;
+
+	struct qpic_ecc *ecc;
+	struct qcom_ecc_stats ecc_stats;
+	struct nand_ecc_engine ecc_eng;
+	phys_addr_t base_phys;
+	dma_addr_t base_dma;
+	dma_addr_t reg_read_dma;
+
+	int		buf_size;
+	int		buf_count;
+	int		buf_start;
+	unsigned int	max_cwperpage;
+
+	int reg_read_pos;
+
+	u32 cmd1, vld;
+	bool exec_opwrite;
+};
+
+/*
+ * NAND chip structure
+ *
+ * @boot_partitions:		array of boot partitions where offset and size of the
+ *				boot partitions are stored
+ *
+ * @chip:			base NAND chip structure
+ * @node:			list node to add itself to host_list in
+ *				qcom_nand_controller
+ *
+ * @nr_boot_partitions:		count of the boot partitions where spare data is not
+ *				protected by ECC
+ *
+ * @cs:				chip select value for this chip
+ * @cw_size:			the number of bytes in a single step/codeword
+ *				of a page, consisting of all data, ecc, spare
+ *				and reserved bytes
+ * @cw_data:			the number of bytes within a codeword protected
+ *				by ECC
+ * @ecc_bytes_hw:		ECC bytes used by controller hardware for this
+ *				chip
+ *
+ * @last_command:		keeps track of last command on this chip. used
+ *				for reading correct status
+ *
+ * @cfg0, cfg1, cfg0_raw..:	NANDc register configurations needed for
+ *				ecc/non-ecc mode for the current nand flash
+ *				device
+ *
+ * @status:			value to be returned if NAND_CMD_STATUS command
+ *				is executed
+ * @codeword_fixup:		keep track of the current layout used by
+ *				the driver for read/write operation.
+ * @use_ecc:			request the controller to use ECC for the
+ *				upcoming read/write
+ * @bch_enabled:		flag to tell whether BCH ECC mode is used
+ */
+struct qcom_nand_host {
+	struct qcom_nand_boot_partition *boot_partitions;
+
+	struct nand_chip chip;
+	struct list_head node;
+
+	int nr_boot_partitions;
+
+	int cs;
+	int cw_size;
+	int cw_data;
+	int ecc_bytes_hw;
+	int spare_bytes;
+	int bbm_size;
+
+	int last_command;
+
+	u32 cfg0, cfg1;
+	u32 cfg0_raw, cfg1_raw;
+	u32 ecc_buf_cfg;
+	u32 ecc_bch_cfg;
+	u32 clrflashstatus;
+	u32 clrreadstatus;
+
+	u8 status;
+	bool codeword_fixup;
+	bool use_ecc;
+	bool bch_enabled;
+};
+
+struct qcom_nand_host *to_qcom_nand_host(struct nand_chip *chip);
+
+struct qcom_nand_controller *get_qcom_nand_controller(struct nand_chip *chip);
+
+void qcom_ecc_enable(struct qcom_ecc *ecc);
+
+void qcom_ecc_disable(struct qcom_ecc *ecc);
+
+struct qcom_ecc *of_qcom_ecc_get(struct device_node *);
+
+int qcom_ecc_config(struct qpic_ecc *ecc, int ecc_strength,
+			bool wide_bus);
+
+int qcom_nandc_alloc(struct qcom_nand_controller *nandc);
+
+void qcom_nandc_unalloc(struct qcom_nand_controller *nandc);
+
+int qcom_nandc_setup(struct qcom_nand_controller *nandc);
+
+struct bam_transaction *
+alloc_bam_transaction(struct qcom_nand_controller *nandc);
+
+void clear_bam_transaction(struct qcom_nand_controller *nandc);
+int prepare_bam_async_desc(struct qcom_nand_controller *nandc,
+				  struct dma_chan *chan,
+				  unsigned long flags);
+int prep_adm_dma_desc(struct qcom_nand_controller *nandc, bool read,
+			     int reg_off, const void *vaddr, int size,
+			     bool flow_control);
+
+int submit_descs(struct qcom_nand_controller *nandc);
+
+void free_descs(struct qcom_nand_controller *nandc);
+
+void nandc_set_reg(struct qcom_nand_controller *nandc, int offset,
+			  u32 val);
+int write_reg_dma(struct qcom_nand_controller *nandc, int first,
+			 int num_regs, unsigned int flags);
+
+int read_reg_dma(struct qcom_nand_controller *nandc, int first,
+			int num_regs, unsigned int flags);
+void clear_read_regs(struct qcom_nand_controller *nandc);
+
+void nandc_read_buffer_sync(struct qcom_nand_controller *nandc,
+					  bool is_cpu);
+struct qpic_ecc *of_qpic_ecc_get(struct device_node *);
+#endif
+