openwrt/target/linux/ipq806x/patches-4.9/861-qcom-mtd-nand-Added-bam-transaction-and-support-addi.patch

From 645c7805f2602569263d7ac78050b2c9e91e3377 Mon Sep 17 00:00:00 2001
From: Ram Chandra Jangir <rjangir@codeaurora.org>
Date: Thu, 20 Apr 2017 10:23:00 +0530
Subject: [PATCH] qcom: mtd: nand: Added bam transaction and support
 additional CSRs

This patch adds the following for NAND BAM DMA support
 - Bam transaction which will be used for any NAND request.
    It contains the array of command elements, command and
    data sgl. This transaction will be resetted before every
    request.
 - Allocation function for NAND BAM transaction which will be
    called only once at probe time.
 - Reset function for NAND BAM transaction which will be called
    before any new NAND request.
 - Add support for additional CSRs.
    NAND_READ_LOCATION - page offset for reading in BAM DMA mode
    NAND_ERASED_CW_DETECT_CFG - status for erased code words
    NAND_BUFFER_STATUS - status for ECC

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Signed-off-by: Ram Chandra Jangir <rjangir@codeaurora.org>
---
 drivers/mtd/nand/qcom_nandc.c    | 631 +++++++++++++++++++++++++++++++++++----
 include/linux/dma/qcom_bam_dma.h | 149 +++++++++
 2 files changed, 721 insertions(+), 59 deletions(-)
 create mode 100644 include/linux/dma/qcom_bam_dma.h

--- a/drivers/mtd/nand/qcom_nandc.c
+++ b/drivers/mtd/nand/qcom_nandc.c
@@ -22,6 +22,7 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/delay.h>
+#include <linux/dma/qcom_bam_dma.h>
 
 /* NANDc reg offsets */
 #define	NAND_FLASH_CMD			0x00
@@ -53,6 +54,8 @@
 #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
 
 /* dummy register offsets, used by write_reg_dma */
 #define	NAND_DEV_CMD1_RESTORE		0xdead
@@ -135,6 +138,11 @@
 #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
@@ -156,6 +164,9 @@
 #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 NAND controller performs reads/writes with ECC in 516 byte chunks.
  * the driver calls the chunks 'step' or 'codeword' interchangeably
@@ -177,12 +188,77 @@
 #define	ECC_BCH_4BIT	BIT(2)
 #define	ECC_BCH_8BIT	BIT(3)
 
+/* Flags used for BAM DMA desc preparation*/
+/* Don't set the EOT in current tx sgl */
+#define DMA_DESC_FLAG_NO_EOT		(0x0001)
+/* Set the NWD flag in current sgl */
+#define DMA_DESC_FLAG_BAM_NWD		(0x0002)
+/* Close current sgl and start writing in another sgl */
+#define DMA_DESC_FLAG_BAM_NEXT_SGL	(0x0004)
+/*
+ * 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 DMA_DESC_ERASED_CW_SET		(0x0008)
+
+/* Returns the dma address for reg read buffer */
+#define REG_BUF_DMA_ADDR(chip, vaddr) \
+	((chip)->reg_read_buf_phys + \
+	((uint8_t *)(vaddr) - (uint8_t *)(chip)->reg_read_buf))
+
+/* Returns the nand register physical address */
+#define NAND_REG_PHYS_ADDRESS(chip, addr) \
+	((chip)->base_dma + (addr))
+
+/* command element array size in bam transaction */
+#define BAM_CMD_ELEMENT_SIZE	(256)
+/* command sgl size in bam transaction */
+#define BAM_CMD_SGL_SIZE	(256)
+/* data sgl size in bam transaction */
+#define BAM_DATA_SGL_SIZE	(128)
+
+/*
+ * This data type corresponds to the BAM transaction which will be used for any
+ * nand request.
+ * @bam_ce - the array of bam command elements
+ * @cmd_sgl - sgl for nand bam command pipe
+ * @tx_sgl - sgl for nand bam consumer pipe
+ * @rx_sgl - sgl for nand bam producer pipe
+ * @bam_ce_index - the index in bam_ce which is available for next sgl request
+ * @pre_bam_ce_index - 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_cnt - no of entries in command sgl.
+ * @tx_sgl_cnt - no of entries in tx sgl.
+ * @rx_sgl_cnt - no of entries in rx sgl.
+ */
+struct bam_transaction {
+	struct bam_cmd_element bam_ce[BAM_CMD_ELEMENT_SIZE];
+	struct qcom_bam_sgl cmd_sgl[BAM_CMD_SGL_SIZE];
+	struct qcom_bam_sgl tx_sgl[BAM_DATA_SGL_SIZE];
+	struct qcom_bam_sgl rx_sgl[BAM_DATA_SGL_SIZE];
+	uint32_t bam_ce_index;
+	uint32_t pre_bam_ce_index;
+	uint32_t cmd_sgl_cnt;
+	uint32_t tx_sgl_cnt;
+	uint32_t rx_sgl_cnt;
+};
+
+/**
+ * This data type corresponds to the nand dma descriptor
+ * @list - list for desc_info
+ * @dir - DMA transfer direction
+ * @sgl - sgl which will be used for single sgl dma descriptor
+ * @dma_desc - low level dma engine descriptor
+ * @bam_desc_data - used for bam desc mappings
+ */
 struct desc_info {
 	struct list_head node;
 
 	enum dma_data_direction dir;
 	struct scatterlist sgl;
 	struct dma_async_tx_descriptor *dma_desc;
+	struct qcom_bam_custom_data bam_desc_data;
 };
 
 /*
@@ -210,6 +286,13 @@ struct nandc_regs {
 	__le32 orig_vld;
 
 	__le32 ecc_buf_cfg;
+	__le32 read_location0;
+	__le32 read_location1;
+	__le32 read_location2;
+	__le32 read_location3;
+
+	__le32 erased_cw_detect_cfg_clr;
+	__le32 erased_cw_detect_cfg_set;
 };
 
 /*
@@ -225,6 +308,7 @@ struct nandc_regs {
  * @aon_clk:			another controller clock
  *
  * @chan:			dma channel
+ * @bam_txn:                   contains the bam transaction address
  * @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)
@@ -250,6 +334,7 @@ struct nandc_regs {
 struct qcom_nand_controller {
 	struct nand_hw_control controller;
 	struct list_head host_list;
+	struct bam_transaction *bam_txn;
 
 	struct device *dev;
 
@@ -350,6 +435,45 @@ struct qcom_nand_driver_data {
 	bool dma_bam_enabled;
 };
 
+/* Allocates and Initializes the BAM transaction */
+struct bam_transaction *alloc_bam_transaction(
+	struct qcom_nand_controller *nandc)
+{
+	struct bam_transaction *bam_txn;
+
+	bam_txn = kzalloc(sizeof(*bam_txn), GFP_KERNEL);
+
+	if (!bam_txn)
+		return NULL;
+
+	bam_txn->bam_ce_index = 0;
+	bam_txn->pre_bam_ce_index = 0;
+	bam_txn->cmd_sgl_cnt = 0;
+	bam_txn->tx_sgl_cnt = 0;
+	bam_txn->rx_sgl_cnt = 0;
+
+	qcom_bam_sg_init_table(bam_txn->cmd_sgl, BAM_CMD_SGL_SIZE);
+	qcom_bam_sg_init_table(bam_txn->tx_sgl, BAM_DATA_SGL_SIZE);
+	qcom_bam_sg_init_table(bam_txn->rx_sgl, BAM_DATA_SGL_SIZE);
+
+	return bam_txn;
+}
+
+/* Clears the BAM transaction index */
+void clear_bam_transaction(struct qcom_nand_controller *nandc)
+{
+	struct bam_transaction *bam_txn = nandc->bam_txn;
+
+	if (!nandc->dma_bam_enabled)
+		return;
+
+	bam_txn->bam_ce_index = 0;
+	bam_txn->pre_bam_ce_index = 0;
+	bam_txn->cmd_sgl_cnt = 0;
+	bam_txn->tx_sgl_cnt = 0;
+	bam_txn->rx_sgl_cnt = 0;
+}
+
 static inline struct qcom_nand_host *to_qcom_nand_host(struct nand_chip *chip)
 {
 	return container_of(chip, struct qcom_nand_host, chip);
@@ -406,6 +530,16 @@ static __le32 *offset_to_nandc_reg(struc
 		return &regs->orig_vld;
 	case NAND_EBI2_ECC_BUF_CFG:
 		return &regs->ecc_buf_cfg;
+	case NAND_BUFFER_STATUS:
+		return &regs->clrreadstatus;
+	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;
 	default:
 		return NULL;
 	}
@@ -447,7 +581,7 @@ static void update_rw_regs(struct qcom_n
 {
 	struct nand_chip *chip = &host->chip;
 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
-	u32 cmd, cfg0, cfg1, ecc_bch_cfg;
+	u32 cmd, cfg0, cfg1, ecc_bch_cfg, read_location0;
 
 	if (read) {
 		if (host->use_ecc)
@@ -464,12 +598,20 @@ static void update_rw_regs(struct qcom_n
 
 		cfg1 = host->cfg1;
 		ecc_bch_cfg = host->ecc_bch_cfg;
+		if (read)
+			read_location0 = (0 << READ_LOCATION_OFFSET) |
+				(host->cw_data << READ_LOCATION_SIZE) |
+				(1 << READ_LOCATION_LAST);
 	} else {
 		cfg0 = (host->cfg0_raw & ~(7U << CW_PER_PAGE)) |
 				(num_cw - 1) << CW_PER_PAGE;
 
 		cfg1 = host->cfg1_raw;
 		ecc_bch_cfg = 1 << ECC_CFG_ECC_DISABLE;
+		if (read)
+			read_location0 = (0 << READ_LOCATION_OFFSET) |
+				(host->cw_size << READ_LOCATION_SIZE) |
+				(1 << READ_LOCATION_LAST);
 	}
 
 	nandc_set_reg(nandc, NAND_FLASH_CMD, cmd);
@@ -480,8 +622,104 @@ static void update_rw_regs(struct qcom_n
 	nandc_set_reg(nandc, NAND_FLASH_STATUS, host->clrflashstatus);
 	nandc_set_reg(nandc, NAND_READ_STATUS, host->clrreadstatus);
 	nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
+
+	if (read)
+		nandc_set_reg(nandc, NAND_READ_LOCATION_0, read_location0);
+}
+
+/*
+ * Prepares the command descriptor for BAM DMA which will be used for NAND
+ * register read and write. 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
+ * DMA_DESC_FLAG_BAM_NEXT_SGL will be used for starting the separate SGL
+ * after the current command element.
+ */
+static int prep_dma_desc_command(struct qcom_nand_controller *nandc, bool read,
+					int reg_off, const void *vaddr,
+					int size, unsigned int flags)
+{
+	int bam_ce_size;
+	int i;
+	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_index];
+
+	/* fill the command desc */
+	for (i = 0; i < size; i++) {
+		if (read) {
+			qcom_prep_bam_ce(&bam_ce_buffer[i],
+				NAND_REG_PHYS_ADDRESS(nandc, reg_off + 4 * i),
+				BAM_READ_COMMAND,
+				REG_BUF_DMA_ADDR(nandc,
+					(unsigned int *)vaddr + i));
+		} else {
+			qcom_prep_bam_ce(&bam_ce_buffer[i],
+				NAND_REG_PHYS_ADDRESS(nandc, reg_off + 4 * i),
+				BAM_WRITE_COMMAND,
+				*((unsigned int *)vaddr + i));
+		}
+	}
+
+	/* use the separate sgl after this command */
+	if (flags & DMA_DESC_FLAG_BAM_NEXT_SGL) {
+		bam_ce_buffer = &bam_txn->bam_ce[bam_txn->pre_bam_ce_index];
+		bam_txn->bam_ce_index += size;
+		bam_ce_size = (bam_txn->bam_ce_index -
+				bam_txn->pre_bam_ce_index) *
+				sizeof(struct bam_cmd_element);
+		sg_set_buf(&bam_txn->cmd_sgl[bam_txn->cmd_sgl_cnt].sgl,
+				bam_ce_buffer,
+				bam_ce_size);
+		if (flags & DMA_DESC_FLAG_BAM_NWD)
+			bam_txn->cmd_sgl[bam_txn->cmd_sgl_cnt].dma_flags =
+				DESC_FLAG_NWD | DESC_FLAG_CMD;
+		else
+			bam_txn->cmd_sgl[bam_txn->cmd_sgl_cnt].dma_flags =
+				DESC_FLAG_CMD;
+
+		bam_txn->cmd_sgl_cnt++;
+		bam_txn->pre_bam_ce_index = bam_txn->bam_ce_index;
+	} else {
+		bam_txn->bam_ce_index += size;
+	}
+
+	return 0;
 }
 
+/*
+ * Prepares the data descriptor for BAM DMA which will be used for NAND
+ * data read and write.
+ */
+static int prep_dma_desc_data_bam(struct qcom_nand_controller *nandc, bool read,
+					int reg_off, const void *vaddr,
+					int size, unsigned int flags)
+{
+	struct bam_transaction *bam_txn = nandc->bam_txn;
+
+	if (read) {
+		sg_set_buf(&bam_txn->rx_sgl[bam_txn->rx_sgl_cnt].sgl,
+				vaddr, size);
+		bam_txn->rx_sgl[bam_txn->rx_sgl_cnt].dma_flags = 0;
+		bam_txn->rx_sgl_cnt++;
+	} else {
+		sg_set_buf(&bam_txn->tx_sgl[bam_txn->tx_sgl_cnt].sgl,
+				vaddr, size);
+		if (flags & DMA_DESC_FLAG_NO_EOT)
+			bam_txn->tx_sgl[bam_txn->tx_sgl_cnt].dma_flags = 0;
+		else
+			bam_txn->tx_sgl[bam_txn->tx_sgl_cnt].dma_flags =
+				DESC_FLAG_EOT;
+
+		bam_txn->tx_sgl_cnt++;
+	}
+
+	return 0;
+}
+
+/* Prepares the dma desciptor for adm dma engine */
 static int prep_dma_desc(struct qcom_nand_controller *nandc, bool read,
 			 int reg_off, const void *vaddr, int size,
 			 bool flow_control)
@@ -560,7 +798,7 @@ err:
  * @num_regs:		number of registers to read
  */
 static int read_reg_dma(struct qcom_nand_controller *nandc, int first,
-			int num_regs)
+			int num_regs, unsigned int flags)
 {
 	bool flow_control = false;
 	void *vaddr;
@@ -569,10 +807,18 @@ static int read_reg_dma(struct qcom_nand
 	if (first == NAND_READ_ID || first == NAND_FLASH_STATUS)
 		flow_control = true;
 
-	size = num_regs * sizeof(u32);
 	vaddr = nandc->reg_read_buf + nandc->reg_read_pos;
 	nandc->reg_read_pos += num_regs;
 
+	if (nandc->dma_bam_enabled) {
+		size = num_regs;
+
+		return prep_dma_desc_command(nandc, true, first, vaddr, size,
+						flags);
+	}
+
+	size = num_regs * sizeof(u32);
+
 	return prep_dma_desc(nandc, true, first, vaddr, size, flow_control);
 }
 
@@ -584,7 +830,7 @@ static int read_reg_dma(struct qcom_nand
  * @num_regs:		number of registers to write
  */
 static int write_reg_dma(struct qcom_nand_controller *nandc, int first,
-			 int num_regs)
+			 int num_regs, unsigned int flags)
 {
 	bool flow_control = false;
 	struct nandc_regs *regs = nandc->regs;
@@ -596,12 +842,29 @@ static int write_reg_dma(struct qcom_nan
 	if (first == NAND_FLASH_CMD)
 		flow_control = true;
 
+	if (first == NAND_ERASED_CW_DETECT_CFG) {
+		if (flags & DMA_DESC_ERASED_CW_SET)
+			vaddr = &regs->erased_cw_detect_cfg_set;
+		else
+			vaddr = &regs->erased_cw_detect_cfg_clr;
+	}
+
+	if (first == NAND_EXEC_CMD)
+		flags |= DMA_DESC_FLAG_BAM_NWD;
+
 	if (first == NAND_DEV_CMD1_RESTORE)
 		first = NAND_DEV_CMD1;
 
 	if (first == NAND_DEV_CMD_VLD_RESTORE)
 		first = NAND_DEV_CMD_VLD;
 
+	if (nandc->dma_bam_enabled) {
+		size = num_regs;
+
+		return prep_dma_desc_command(nandc, false, first, vaddr, size,
+						flags);
+	}
+
 	size = num_regs * sizeof(u32);
 
 	return prep_dma_desc(nandc, false, first, vaddr, size, flow_control);
@@ -616,8 +879,12 @@ static int write_reg_dma(struct qcom_nan
  * @size:		DMA transaction size in bytes
  */
 static int read_data_dma(struct qcom_nand_controller *nandc, int reg_off,
-			 const u8 *vaddr, int size)
+			 const u8 *vaddr, int size, unsigned int flags)
 {
+	if (nandc->dma_bam_enabled)
+		return prep_dma_desc_data_bam(nandc, true, reg_off, vaddr, size,
+						flags);
+
 	return prep_dma_desc(nandc, true, reg_off, vaddr, size, false);
 }
 
@@ -630,8 +897,12 @@ static int read_data_dma(struct qcom_nan
  * @size:		DMA transaction size in bytes
  */
 static int write_data_dma(struct qcom_nand_controller *nandc, int reg_off,
-			  const u8 *vaddr, int size)
+			  const u8 *vaddr, int size, unsigned int flags)
 {
+	if (nandc->dma_bam_enabled)
+		return prep_dma_desc_data_bam(nandc, false, reg_off, vaddr,
+							size, flags);
+
 	return prep_dma_desc(nandc, false, reg_off, vaddr, size, false);
 }
 
@@ -641,14 +912,57 @@ static int write_data_dma(struct qcom_na
  */
 static void config_cw_read(struct qcom_nand_controller *nandc)
 {
-	write_reg_dma(nandc, NAND_FLASH_CMD, 3);
-	write_reg_dma(nandc, NAND_DEV0_CFG0, 3);
-	write_reg_dma(nandc, NAND_EBI2_ECC_BUF_CFG, 1);
 
-	write_reg_dma(nandc, NAND_EXEC_CMD, 1);
+	write_reg_dma(nandc, NAND_FLASH_CMD, 3, 0);
+	write_reg_dma(nandc, NAND_DEV0_CFG0, 3, 0);
+	write_reg_dma(nandc, NAND_EBI2_ECC_BUF_CFG, 1, 0);
+
+	write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1, 0);
+	write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1,
+				DMA_DESC_ERASED_CW_SET);
+	if (nandc->dma_bam_enabled)
+		write_reg_dma(nandc, NAND_READ_LOCATION_0, 1,
+				DMA_DESC_FLAG_BAM_NEXT_SGL);
 
-	read_reg_dma(nandc, NAND_FLASH_STATUS, 2);
-	read_reg_dma(nandc, NAND_ERASED_CW_DETECT_STATUS, 1);
+
+	write_reg_dma(nandc, NAND_EXEC_CMD, 1, DMA_DESC_FLAG_BAM_NWD |
+				DMA_DESC_FLAG_BAM_NEXT_SGL);
+
+	read_reg_dma(nandc, NAND_FLASH_STATUS, 2, 0);
+	read_reg_dma(nandc, NAND_ERASED_CW_DETECT_STATUS, 1,
+				DMA_DESC_FLAG_BAM_NEXT_SGL);
+}
+
+/*
+ * Helpers to prepare DMA descriptors for configuring registers
+ * before reading a NAND page with BAM.
+ */
+static void config_bam_page_read(struct qcom_nand_controller *nandc)
+{
+	write_reg_dma(nandc, NAND_FLASH_CMD, 3, 0);
+	write_reg_dma(nandc, NAND_DEV0_CFG0, 3, 0);
+	write_reg_dma(nandc, NAND_EBI2_ECC_BUF_CFG, 1, 0);
+	write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1, 0);
+	write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1,
+				DMA_DESC_ERASED_CW_SET |
+				DMA_DESC_FLAG_BAM_NEXT_SGL);
+}
+
+/*
+ * Helpers to prepare DMA descriptors for configuring registers
+ * before reading each codeword in NAND page with BAM.
+ */
+static void config_bam_cw_read(struct qcom_nand_controller *nandc)
+{
+	if (nandc->dma_bam_enabled)
+		write_reg_dma(nandc, NAND_READ_LOCATION_0, 4, 0);
+
+	write_reg_dma(nandc, NAND_FLASH_CMD, 1, DMA_DESC_FLAG_BAM_NEXT_SGL);
+	write_reg_dma(nandc, NAND_EXEC_CMD, 1, DMA_DESC_FLAG_BAM_NEXT_SGL);
+
+	read_reg_dma(nandc, NAND_FLASH_STATUS, 2, 0);
+	read_reg_dma(nandc, NAND_ERASED_CW_DETECT_STATUS, 1,
+				DMA_DESC_FLAG_BAM_NEXT_SGL);
 }
 
 /*
@@ -657,19 +971,20 @@ static void config_cw_read(struct qcom_n
  */
 static void config_cw_write_pre(struct qcom_nand_controller *nandc)
 {
-	write_reg_dma(nandc, NAND_FLASH_CMD, 3);
-	write_reg_dma(nandc, NAND_DEV0_CFG0, 3);
-	write_reg_dma(nandc, NAND_EBI2_ECC_BUF_CFG, 1);
+	write_reg_dma(nandc, NAND_FLASH_CMD, 3, 0);
+	write_reg_dma(nandc, NAND_DEV0_CFG0, 3, 0);
+	write_reg_dma(nandc, NAND_EBI2_ECC_BUF_CFG, 1,
+				DMA_DESC_FLAG_BAM_NEXT_SGL);
 }
 
 static void config_cw_write_post(struct qcom_nand_controller *nandc)
 {
-	write_reg_dma(nandc, NAND_EXEC_CMD, 1);
+	write_reg_dma(nandc, NAND_EXEC_CMD, 1, DMA_DESC_FLAG_BAM_NEXT_SGL);
 
-	read_reg_dma(nandc, NAND_FLASH_STATUS, 1);
+	read_reg_dma(nandc, NAND_FLASH_STATUS, 1, DMA_DESC_FLAG_BAM_NEXT_SGL);
 
-	write_reg_dma(nandc, NAND_FLASH_STATUS, 1);
-	write_reg_dma(nandc, NAND_READ_STATUS, 1);
+	write_reg_dma(nandc, NAND_FLASH_STATUS, 1, 0);
+	write_reg_dma(nandc, NAND_READ_STATUS, 1, DMA_DESC_FLAG_BAM_NEXT_SGL);
 }
 
 /*
@@ -683,6 +998,8 @@ static int nandc_param(struct qcom_nand_
 	struct nand_chip *chip = &host->chip;
 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
 
+	clear_bam_transaction(nandc);
+
 	/*
 	 * NAND_CMD_PARAM is called before we know much about the FLASH chip
 	 * in use. we configure the controller to perform a raw read of 512
@@ -715,9 +1032,13 @@ static int nandc_param(struct qcom_nand_
 
 	nandc_set_reg(nandc, NAND_DEV_CMD1_RESTORE, nandc->cmd1);
 	nandc_set_reg(nandc, NAND_DEV_CMD_VLD_RESTORE, nandc->vld);
+	nandc_set_reg(nandc, NAND_READ_LOCATION_0,
+				(0 << READ_LOCATION_OFFSET) |
+				(512 << READ_LOCATION_SIZE) |
+				(1 << READ_LOCATION_LAST));
 
-	write_reg_dma(nandc, NAND_DEV_CMD_VLD, 1);
-	write_reg_dma(nandc, NAND_DEV_CMD1, 1);
+	write_reg_dma(nandc, NAND_DEV_CMD_VLD, 1, 0);
+	write_reg_dma(nandc, NAND_DEV_CMD1, 1, DMA_DESC_FLAG_BAM_NEXT_SGL);
 
 	nandc->buf_count = 512;
 	memset(nandc->data_buffer, 0xff, nandc->buf_count);
@@ -725,11 +1046,12 @@ static int nandc_param(struct qcom_nand_
 	config_cw_read(nandc);
 
 	read_data_dma(nandc, FLASH_BUF_ACC, nandc->data_buffer,
-		      nandc->buf_count);
+		      nandc->buf_count, 0);
 
 	/* restore CMD1 and VLD regs */
-	write_reg_dma(nandc, NAND_DEV_CMD1_RESTORE, 1);
-	write_reg_dma(nandc, NAND_DEV_CMD_VLD_RESTORE, 1);
+	write_reg_dma(nandc, NAND_DEV_CMD1_RESTORE, 1, 0);
+	write_reg_dma(nandc, NAND_DEV_CMD_VLD_RESTORE, 1,
+				DMA_DESC_FLAG_BAM_NEXT_SGL);
 
 	return 0;
 }
@@ -740,6 +1062,8 @@ static int erase_block(struct qcom_nand_
 	struct nand_chip *chip = &host->chip;
 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
 
+	clear_bam_transaction(nandc);
+
 	nandc_set_reg(nandc, NAND_FLASH_CMD,
 		      BLOCK_ERASE | PAGE_ACC | LAST_PAGE);
 	nandc_set_reg(nandc, NAND_ADDR0, page_addr);
@@ -751,14 +1075,15 @@ static int erase_block(struct qcom_nand_
 	nandc_set_reg(nandc, NAND_FLASH_STATUS, host->clrflashstatus);
 	nandc_set_reg(nandc, NAND_READ_STATUS, host->clrreadstatus);
 
-	write_reg_dma(nandc, NAND_FLASH_CMD, 3);
-	write_reg_dma(nandc, NAND_DEV0_CFG0, 2);
-	write_reg_dma(nandc, NAND_EXEC_CMD, 1);
 
-	read_reg_dma(nandc, NAND_FLASH_STATUS, 1);
+	write_reg_dma(nandc, NAND_FLASH_CMD, 3, DMA_DESC_FLAG_BAM_NEXT_SGL);
+	write_reg_dma(nandc, NAND_DEV0_CFG0, 2, DMA_DESC_FLAG_BAM_NEXT_SGL);
+	write_reg_dma(nandc, NAND_EXEC_CMD, 1, DMA_DESC_FLAG_BAM_NEXT_SGL);
+
+	read_reg_dma(nandc, NAND_FLASH_STATUS, 1, DMA_DESC_FLAG_BAM_NEXT_SGL);
 
-	write_reg_dma(nandc, NAND_FLASH_STATUS, 1);
-	write_reg_dma(nandc, NAND_READ_STATUS, 1);
+	write_reg_dma(nandc, NAND_FLASH_STATUS, 1, 0);
+	write_reg_dma(nandc, NAND_READ_STATUS, 1, DMA_DESC_FLAG_BAM_NEXT_SGL);
 
 	return 0;
 }
@@ -772,16 +1097,19 @@ static int read_id(struct qcom_nand_host
 	if (column == -1)
 		return 0;
 
+	clear_bam_transaction(nandc);
+
 	nandc_set_reg(nandc, NAND_FLASH_CMD, FETCH_ID);
 	nandc_set_reg(nandc, NAND_ADDR0, column);
 	nandc_set_reg(nandc, NAND_ADDR1, 0);
-	nandc_set_reg(nandc, NAND_FLASH_CHIP_SELECT, DM_EN);
+	nandc_set_reg(nandc, NAND_FLASH_CHIP_SELECT,
+			nandc->dma_bam_enabled ? 0 : DM_EN);
 	nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
 
-	write_reg_dma(nandc, NAND_FLASH_CMD, 4);
-	write_reg_dma(nandc, NAND_EXEC_CMD, 1);
+	write_reg_dma(nandc, NAND_FLASH_CMD, 4, DMA_DESC_FLAG_BAM_NEXT_SGL);
+	write_reg_dma(nandc, NAND_EXEC_CMD, 1, DMA_DESC_FLAG_BAM_NEXT_SGL);
 
-	read_reg_dma(nandc, NAND_READ_ID, 1);
+	read_reg_dma(nandc, NAND_READ_ID, 1, DMA_DESC_FLAG_BAM_NEXT_SGL);
 
 	return 0;
 }
@@ -792,28 +1120,108 @@ static int reset(struct qcom_nand_host *
 	struct nand_chip *chip = &host->chip;
 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
 
+	clear_bam_transaction(nandc);
+
 	nandc_set_reg(nandc, NAND_FLASH_CMD, RESET_DEVICE);
 	nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
 
-	write_reg_dma(nandc, NAND_FLASH_CMD, 1);
-	write_reg_dma(nandc, NAND_EXEC_CMD, 1);
+	write_reg_dma(nandc, NAND_FLASH_CMD, 1, DMA_DESC_FLAG_BAM_NEXT_SGL);
+	write_reg_dma(nandc, NAND_EXEC_CMD, 1, DMA_DESC_FLAG_BAM_NEXT_SGL);
 
-	read_reg_dma(nandc, NAND_FLASH_STATUS, 1);
+	read_reg_dma(nandc, NAND_FLASH_STATUS, 1, DMA_DESC_FLAG_BAM_NEXT_SGL);
 
 	return 0;
 }
 
+static int prepare_bam_async_desc(struct qcom_nand_controller *nandc,
+				struct dma_chan *chan,
+				struct qcom_bam_sgl *bam_sgl,
+				int sgl_cnt,
+				enum dma_transfer_direction direction)
+{
+	struct desc_info *desc;
+	struct dma_async_tx_descriptor *dma_desc;
+
+	if (!qcom_bam_map_sg(nandc->dev, bam_sgl, sgl_cnt, direction)) {
+		dev_err(nandc->dev, "failure in mapping sgl\n");
+		return -ENOMEM;
+	}
+
+	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
+	if (!desc) {
+		qcom_bam_unmap_sg(nandc->dev, bam_sgl, sgl_cnt, direction);
+		return -ENOMEM;
+	}
+
+
+	desc->bam_desc_data.dir = direction;
+	desc->bam_desc_data.sgl_cnt = sgl_cnt;
+	desc->bam_desc_data.bam_sgl = bam_sgl;
+
+	dma_desc = dmaengine_prep_dma_custom_mapping(chan,
+			&desc->bam_desc_data,
+			0);
+
+	if (!dma_desc) {
+		dev_err(nandc->dev, "failure in cmd prep desc\n");
+		qcom_bam_unmap_sg(nandc->dev, bam_sgl, sgl_cnt, direction);
+		kfree(desc);
+		return -EINVAL;
+	}
+
+	desc->dma_desc = dma_desc;
+
+	list_add_tail(&desc->node, &nandc->desc_list);
+
+	return 0;
+
+}
+
 /* helpers to submit/free our list of dma descriptors */
 static 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->dma_bam_enabled) {
+		if (bam_txn->rx_sgl_cnt) {
+			r = prepare_bam_async_desc(nandc, nandc->rx_chan,
+				bam_txn->rx_sgl, bam_txn->rx_sgl_cnt,
+				DMA_DEV_TO_MEM);
+			if (r)
+				return r;
+		}
+
+		if (bam_txn->tx_sgl_cnt) {
+			r = prepare_bam_async_desc(nandc, nandc->tx_chan,
+				bam_txn->tx_sgl, bam_txn->tx_sgl_cnt,
+				DMA_MEM_TO_DEV);
+			if (r)
+				return r;
+		}
+
+		r = prepare_bam_async_desc(nandc, nandc->cmd_chan,
+			bam_txn->cmd_sgl, bam_txn->cmd_sgl_cnt,
+			DMA_MEM_TO_DEV);
+		if (r)
+			return r;
+	}
 
 	list_for_each_entry(desc, &nandc->desc_list, node)
 		cookie = dmaengine_submit(desc->dma_desc);
 
-	if (dma_sync_wait(nandc->chan, cookie) != DMA_COMPLETE)
-		return -ETIMEDOUT;
+	if (nandc->dma_bam_enabled) {
+		dma_async_issue_pending(nandc->tx_chan);
+		dma_async_issue_pending(nandc->rx_chan);
+
+		if (dma_sync_wait(nandc->cmd_chan, cookie) != DMA_COMPLETE)
+			return -ETIMEDOUT;
+	} else {
+		if (dma_sync_wait(nandc->chan, cookie) != DMA_COMPLETE)
+			return -ETIMEDOUT;
+	}
 
 	return 0;
 }
@@ -824,7 +1232,16 @@ static void free_descs(struct qcom_nand_
 
 	list_for_each_entry_safe(desc, n, &nandc->desc_list, node) {
 		list_del(&desc->node);
-		dma_unmap_sg(nandc->dev, &desc->sgl, 1, desc->dir);
+
+		if (nandc->dma_bam_enabled)
+			qcom_bam_unmap_sg(nandc->dev,
+				desc->bam_desc_data.bam_sgl,
+				desc->bam_desc_data.sgl_cnt,
+				desc->bam_desc_data.dir);
+		else
+			dma_unmap_sg(nandc->dev, &desc->sgl, 1,
+				desc->dir);
+
 		kfree(desc);
 	}
 }
@@ -1135,6 +1552,9 @@ static int read_page_ecc(struct qcom_nan
 	struct nand_ecc_ctrl *ecc = &chip->ecc;
 	int i, ret;
 
+	if (nandc->dma_bam_enabled)
+		config_bam_page_read(nandc);
+
 	/* queue cmd descs for each codeword */
 	for (i = 0; i < ecc->steps; i++) {
 		int data_size, oob_size;
@@ -1148,11 +1568,36 @@ static int read_page_ecc(struct qcom_nan
 			oob_size = host->ecc_bytes_hw + host->spare_bytes;
 		}
 
-		config_cw_read(nandc);
+		if (nandc->dma_bam_enabled) {
+			if (data_buf && oob_buf) {
+				nandc_set_reg(nandc, NAND_READ_LOCATION_0,
+					(0 << READ_LOCATION_OFFSET) |
+					(data_size << READ_LOCATION_SIZE) |
+					(0 << READ_LOCATION_LAST));
+				nandc_set_reg(nandc, NAND_READ_LOCATION_1,
+					(data_size << READ_LOCATION_OFFSET) |
+					(oob_size << READ_LOCATION_SIZE) |
+					(1 << READ_LOCATION_LAST));
+			} else if (data_buf) {
+				nandc_set_reg(nandc, NAND_READ_LOCATION_0,
+					(0 << READ_LOCATION_OFFSET) |
+					(data_size << READ_LOCATION_SIZE) |
+					(1 << READ_LOCATION_LAST));
+			} else {
+				nandc_set_reg(nandc, NAND_READ_LOCATION_0,
+					(data_size << READ_LOCATION_OFFSET) |
+					(oob_size << READ_LOCATION_SIZE) |
+					(1 << READ_LOCATION_LAST));
+			}
+
+			config_bam_cw_read(nandc);
+		} else {
+			config_cw_read(nandc);
+		}
 
 		if (data_buf)
 			read_data_dma(nandc, FLASH_BUF_ACC, data_buf,
-				      data_size);
+				      data_size, 0);
 
 		/*
 		 * when ecc is enabled, the controller doesn't read the real
@@ -1168,7 +1613,7 @@ static int read_page_ecc(struct qcom_nan
 				*oob_buf++ = 0xff;
 
 			read_data_dma(nandc, FLASH_BUF_ACC + data_size,
-				      oob_buf, oob_size);
+				      oob_buf, oob_size, 0);
 		}
 
 		if (data_buf)
@@ -1207,10 +1652,14 @@ static int copy_last_cw(struct qcom_nand
 
 	set_address(host, host->cw_size * (ecc->steps - 1), page);
 	update_rw_regs(host, 1, true);
+	nandc_set_reg(nandc, NAND_READ_LOCATION_0,
+			(0 << READ_LOCATION_OFFSET) |
+			(size << READ_LOCATION_SIZE) |
+			(1 << READ_LOCATION_LAST));
 
 	config_cw_read(nandc);
 
-	read_data_dma(nandc, FLASH_BUF_ACC, nandc->data_buffer, size);
+	read_data_dma(nandc, FLASH_BUF_ACC, nandc->data_buffer, size, 0);
 
 	ret = submit_descs(nandc);
 	if (ret)
@@ -1233,6 +1682,7 @@ static int qcom_nandc_read_page(struct m
 	data_buf = buf;
 	oob_buf = oob_required ? chip->oob_poi : NULL;
 
+	clear_bam_transaction(nandc);
 	ret = read_page_ecc(host, data_buf, oob_buf);
 	if (ret) {
 		dev_err(nandc->dev, "failure to read page\n");
@@ -1252,13 +1702,19 @@ static int qcom_nandc_read_page_raw(stru
 	u8 *data_buf, *oob_buf;
 	struct nand_ecc_ctrl *ecc = &chip->ecc;
 	int i, ret;
+	int read_location;
 
 	data_buf = buf;
 	oob_buf = chip->oob_poi;
 
 	host->use_ecc = false;
+
+	clear_bam_transaction(nandc);
 	update_rw_regs(host, ecc->steps, true);
 
+	if (nandc->dma_bam_enabled)
+		config_bam_page_read(nandc);
+
 	for (i = 0; i < ecc->steps; i++) {
 		int data_size1, data_size2, oob_size1, oob_size2;
 		int reg_off = FLASH_BUF_ACC;
@@ -1276,21 +1732,49 @@ static int qcom_nandc_read_page_raw(stru
 			oob_size2 = host->ecc_bytes_hw + host->spare_bytes;
 		}
 
-		config_cw_read(nandc);
+		if (nandc->dma_bam_enabled) {
+			read_location = 0;
+			nandc_set_reg(nandc, NAND_READ_LOCATION_0,
+				(read_location << READ_LOCATION_OFFSET) |
+				(data_size1 << READ_LOCATION_SIZE) |
+				(0 << READ_LOCATION_LAST));
+			read_location += data_size1;
+
+			nandc_set_reg(nandc, NAND_READ_LOCATION_1,
+				(read_location << READ_LOCATION_OFFSET) |
+				(oob_size1 << READ_LOCATION_SIZE) |
+				(0 << READ_LOCATION_LAST));
+			read_location += oob_size1;
+
+			nandc_set_reg(nandc, NAND_READ_LOCATION_2,
+				(read_location << READ_LOCATION_OFFSET) |
+				(data_size2 << READ_LOCATION_SIZE) |
+				(0 << READ_LOCATION_LAST));
+			read_location += data_size2;
+
+			nandc_set_reg(nandc, NAND_READ_LOCATION_3,
+				(read_location << READ_LOCATION_OFFSET) |
+				(oob_size2 << READ_LOCATION_SIZE) |
+				(1 << READ_LOCATION_LAST));
+
+			config_bam_cw_read(nandc);
+		} else {
+			config_cw_read(nandc);
+		}
 
-		read_data_dma(nandc, reg_off, data_buf, data_size1);
+		read_data_dma(nandc, reg_off, data_buf, data_size1, 0);
 		reg_off += data_size1;
 		data_buf += data_size1;
 
-		read_data_dma(nandc, reg_off, oob_buf, oob_size1);
+		read_data_dma(nandc, reg_off, oob_buf, oob_size1, 0);
 		reg_off += oob_size1;
 		oob_buf += oob_size1;
 
-		read_data_dma(nandc, reg_off, data_buf, data_size2);
+		read_data_dma(nandc, reg_off, data_buf, data_size2, 0);
 		reg_off += data_size2;
 		data_buf += data_size2;
 
-		read_data_dma(nandc, reg_off, oob_buf, oob_size2);
+		read_data_dma(nandc, reg_off, oob_buf, oob_size2, 0);
 		oob_buf += oob_size2;
 	}
 
@@ -1313,6 +1797,7 @@ static int qcom_nandc_read_oob(struct mt
 	int ret;
 
 	clear_read_regs(nandc);
+	clear_bam_transaction(nandc);
 
 	host->use_ecc = true;
 	set_address(host, 0, page);
@@ -1336,6 +1821,7 @@ static int qcom_nandc_write_page(struct
 	int i, ret;
 
 	clear_read_regs(nandc);
+	clear_bam_transaction(nandc);
 
 	data_buf = (u8 *)buf;
 	oob_buf = chip->oob_poi;
@@ -1357,7 +1843,8 @@ static int qcom_nandc_write_page(struct
 
 		config_cw_write_pre(nandc);
 
-		write_data_dma(nandc, FLASH_BUF_ACC, data_buf, data_size);
+		write_data_dma(nandc, FLASH_BUF_ACC, data_buf, data_size,
+				i == (ecc->steps - 1) ? DMA_DESC_FLAG_NO_EOT : 0);
 
 		/*
 		 * when ECC is enabled, we don't really need to write anything
@@ -1370,7 +1857,7 @@ static int qcom_nandc_write_page(struct
 			oob_buf += host->bbm_size;
 
 			write_data_dma(nandc, FLASH_BUF_ACC + data_size,
-				       oob_buf, oob_size);
+				       oob_buf, oob_size, 0);
 		}
 
 		config_cw_write_post(nandc);
@@ -1400,6 +1887,7 @@ static int qcom_nandc_write_page_raw(str
 	int i, ret;
 
 	clear_read_regs(nandc);
+	clear_bam_transaction(nandc);
 
 	data_buf = (u8 *)buf;
 	oob_buf = chip->oob_poi;
@@ -1426,19 +1914,22 @@ static int qcom_nandc_write_page_raw(str
 
 		config_cw_write_pre(nandc);
 
-		write_data_dma(nandc, reg_off, data_buf, data_size1);
+		write_data_dma(nandc, reg_off, data_buf, data_size1,
+					DMA_DESC_FLAG_NO_EOT);
 		reg_off += data_size1;
 		data_buf += data_size1;
 
-		write_data_dma(nandc, reg_off, oob_buf, oob_size1);
+		write_data_dma(nandc, reg_off, oob_buf, oob_size1,
+					DMA_DESC_FLAG_NO_EOT);
 		reg_off += oob_size1;
 		oob_buf += oob_size1;
 
-		write_data_dma(nandc, reg_off, data_buf, data_size2);
+		write_data_dma(nandc, reg_off, data_buf, data_size2,
+					DMA_DESC_FLAG_NO_EOT);
 		reg_off += data_size2;
 		data_buf += data_size2;
 
-		write_data_dma(nandc, reg_off, oob_buf, oob_size2);
+		write_data_dma(nandc, reg_off, oob_buf, oob_size2, 0);
 		oob_buf += oob_size2;
 
 		config_cw_write_post(nandc);
@@ -1474,6 +1965,7 @@ static int qcom_nandc_write_oob(struct m
 
 	host->use_ecc = true;
 
+	clear_bam_transaction(nandc);
 	ret = copy_last_cw(host, page);
 	if (ret)
 		return ret;
@@ -1493,7 +1985,7 @@ static int qcom_nandc_write_oob(struct m
 
 	config_cw_write_pre(nandc);
 	write_data_dma(nandc, FLASH_BUF_ACC, nandc->data_buffer,
-		       data_size + oob_size);
+		       data_size + oob_size, 0);
 	config_cw_write_post(nandc);
 
 	ret = submit_descs(nandc);
@@ -1531,6 +2023,7 @@ static int qcom_nandc_block_bad(struct m
 	 */
 	host->use_ecc = false;
 
+	clear_bam_transaction(nandc);
 	ret = copy_last_cw(host, page);
 	if (ret)
 		goto err;
@@ -1561,6 +2054,7 @@ static int qcom_nandc_block_markbad(stru
 	int page, ret, status = 0;
 
 	clear_read_regs(nandc);
+	clear_bam_transaction(nandc);
 
 	/*
 	 * to mark the BBM as bad, we flash the entire last codeword with 0s.
@@ -1577,7 +2071,8 @@ static int qcom_nandc_block_markbad(stru
 	update_rw_regs(host, 1, false);
 
 	config_cw_write_pre(nandc);
-	write_data_dma(nandc, FLASH_BUF_ACC, nandc->data_buffer, host->cw_size);
+	write_data_dma(nandc, FLASH_BUF_ACC, nandc->data_buffer,
+				host->cw_size, 0);
 	config_cw_write_post(nandc);
 
 	ret = submit_descs(nandc);
@@ -1937,6 +2432,8 @@ static int qcom_nand_host_setup(struct q
 
 	host->clrflashstatus = FS_READY_BSY_N;
 	host->clrreadstatus = 0xc0;
+	nandc->regs->erased_cw_detect_cfg_clr = CLR_ERASED_PAGE_DET;
+	nandc->regs->erased_cw_detect_cfg_set = SET_ERASED_PAGE_DET;
 
 	dev_dbg(nandc->dev,
 		"cfg0 %x cfg1 %x ecc_buf_cfg %x ecc_bch cfg %x cw_size %d cw_data %d strength %d parity_bytes %d steps %d\n",
@@ -2015,6 +2512,12 @@ static int qcom_nandc_alloc(struct qcom_
 			dev_err(nandc->dev, "failed to request cmd channel\n");
 			return -ENODEV;
 		}
+
+		nandc->bam_txn = alloc_bam_transaction(nandc);
+		if (!nandc->bam_txn) {
+			dev_err(nandc->dev, "failed to allocate bam transaction\n");
+			return -ENOMEM;
+		}
 	}
 
 	INIT_LIST_HEAD(&nandc->desc_list);
@@ -2050,6 +2553,9 @@ static void qcom_nandc_unalloc(struct qc
 			devm_kfree(nandc->dev, nandc->reg_read_buf);
 	}
 
+	if (nandc->bam_txn)
+		devm_kfree(nandc->dev, nandc->bam_txn);
+
 	if (nandc->regs)
 		devm_kfree(nandc->dev, nandc->regs);
 
@@ -2060,12 +2566,19 @@ static void qcom_nandc_unalloc(struct qc
 /* one time setup of a few nand controller registers */
 static int qcom_nandc_setup(struct qcom_nand_controller *nandc)
 {
+	u32 nand_ctrl;
+
 	/* kill onenand */
 	nandc_write(nandc, SFLASHC_BURST_CFG, 0);
 	nandc_write(nandc, NAND_DEV_CMD_VLD, NAND_DEV_CMD_VLD_VAL);
 
-	/* enable ADM DMA */
-	nandc_write(nandc, NAND_FLASH_CHIP_SELECT, DM_EN);
+	/* enable ADM or BAM DMA */
+	if (!nandc->dma_bam_enabled) {
+		nandc_write(nandc, NAND_FLASH_CHIP_SELECT, DM_EN);
+	} else {
+		nand_ctrl = nandc_read(nandc, NAND_CTRL);
+		nandc_write(nandc, NAND_CTRL, nand_ctrl | BAM_MODE_EN);
+	}
 
 	/* save the original values of these registers */
 	nandc->cmd1 = nandc_read(nandc, NAND_DEV_CMD1);
--- /dev/null
+++ b/include/linux/dma/qcom_bam_dma.h
@@ -0,0 +1,149 @@
+/*
+ * Copyright (c) 2017, The Linux Foundation. All rights reserved.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef _QCOM_BAM_DMA_H
+#define _QCOM_BAM_DMA_H
+
+#include <linux/dma-mapping.h>
+
+#define DESC_FLAG_INT BIT(15)
+#define DESC_FLAG_EOT BIT(14)
+#define DESC_FLAG_EOB BIT(13)
+#define DESC_FLAG_NWD BIT(12)
+#define DESC_FLAG_CMD BIT(11)
+
+/*
+ * QCOM BAM DMA SGL struct
+ *
+ * @sgl: DMA SGL
+ * @dma_flags: BAM DMA flags
+ */
+struct qcom_bam_sgl {
+	struct scatterlist sgl;
+	unsigned int dma_flags;
+};
+
+/*
+ * This data type corresponds to the native Command Element
+ * supported by BAM DMA Engine.
+ *
+ * @addr - register address.
+ * @command - command type.
+ * @data - for write command: content to be written into peripheral register.
+ *	 for read command: dest addr to write peripheral register value to.
+ * @mask - register mask.
+ * @reserved - for future usage.
+ *
+ */
+struct bam_cmd_element {
+	__le32 addr:24;
+	__le32 command:8;
+	__le32 data;
+	__le32 mask;
+	__le32 reserved;
+};
+
+/*
+ * This enum indicates the command type in a command element
+ */
+enum bam_command_type {
+	BAM_WRITE_COMMAND = 0,
+	BAM_READ_COMMAND,
+};
+
+/*
+ * qcom_bam_sg_init_table - Init QCOM BAM SGL
+ * @bam_sgl: bam sgl
+ * @nents: number of entries in bam sgl
+ *
+ * This function performs the initialization for each SGL in BAM SGL
+ * with generic SGL API.
+ */
+static inline void qcom_bam_sg_init_table(struct qcom_bam_sgl *bam_sgl,
+		unsigned int nents)
+{
+	int i;
+
+	for (i = 0; i < nents; i++)
+		sg_init_table(&bam_sgl[i].sgl, 1);
+}
+
+/*
+ * qcom_bam_unmap_sg - Unmap QCOM BAM SGL
+ * @dev: device for which unmapping needs to be done
+ * @bam_sgl: bam sgl
+ * @nents: number of entries in bam sgl
+ * @dir: dma transfer direction
+ *
+ * This function performs the DMA unmapping for each SGL in BAM SGL
+ * with generic SGL API.
+ */
+static inline void qcom_bam_unmap_sg(struct device *dev,
+	struct qcom_bam_sgl *bam_sgl, int nents, enum dma_data_direction dir)
+{
+	int i;
+
+	for (i = 0; i < nents; i++)
+		dma_unmap_sg(dev, &bam_sgl[i].sgl, 1, dir);
+}
+
+/*
+ * qcom_bam_map_sg - Map QCOM BAM SGL
+ * @dev: device for which mapping needs to be done
+ * @bam_sgl: bam sgl
+ * @nents: number of entries in bam sgl
+ * @dir: dma transfer direction
+ *
+ * This function performs the DMA mapping for each SGL in BAM SGL
+ * with generic SGL API.
+ *
+ * returns 0 on error and > 0 on success
+ */
+static inline int qcom_bam_map_sg(struct device *dev,
+	struct qcom_bam_sgl *bam_sgl, int nents, enum dma_data_direction dir)
+{
+	int i, ret = 0;
+
+	for (i = 0; i < nents; i++) {
+		ret = dma_map_sg(dev, &bam_sgl[i].sgl, 1, dir);
+		if (!ret)
+			break;
+	}
+
+	/* unmap the mapped sgl from previous loop in case of error */
+	if (!ret)
+		qcom_bam_unmap_sg(dev, bam_sgl, i, dir);
+
+	return ret;
+}
+
+/*
+ * qcom_prep_bam_ce - Wrapper function to prepare a single BAM command element
+ *	with the data that is passed to this function.
+ * @bam_ce: bam command element
+ * @addr: target address
+ * @command: command in bam_command_type
+ * @data: actual data for write and dest addr for read
+ */
+static inline void qcom_prep_bam_ce(struct bam_cmd_element *bam_ce,
+				uint32_t addr, uint32_t command, uint32_t data)
+{
+	bam_ce->addr = cpu_to_le32(addr);
+	bam_ce->command = cpu_to_le32(command);
+	bam_ce->data = cpu_to_le32(data);
+	bam_ce->mask = 0xFFFFFFFF;
+}
+#endif