1 files changed, 759 insertions, 0 deletions
diff --git a/drivers/mtd/nand/qpic_common.c b/drivers/mtd/nand/qpic_common.c
new file mode 100644
index 000000000000..e0ed25b5afea
--- /dev/null
+++ b/drivers/mtd/nand/qpic_common.c
@@ -0,0 +1,759 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2016, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved
+ */
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/dma/qcom_adm.h>
+#include <linux/dma/qcom_bam_dma.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/mtd/nand-qpic-common.h>
+
+/**
+ * qcom_free_bam_transaction() - Frees the BAM transaction memory
+ * @nandc: qpic nand controller
+ *
+ * This function frees the bam transaction memory
+ */
+void qcom_free_bam_transaction(struct qcom_nand_controller *nandc)
+{
+	struct bam_transaction *bam_txn = nandc->bam_txn;
+
+	kfree(bam_txn);
+}
+EXPORT_SYMBOL(qcom_free_bam_transaction);
+
+/**
+ * qcom_alloc_bam_transaction() - allocate BAM transaction
+ * @nandc: qpic nand controller
+ *
+ * This function will allocate and initialize the BAM transaction structure
+ */
+struct bam_transaction *
+qcom_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 = kzalloc(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(qcom_alloc_bam_transaction);
+
+/**
+ * qcom_clear_bam_transaction() - Clears the BAM transaction
+ * @nandc: qpic nand controller
+ *
+ * This function will clear the BAM transaction indexes.
+ */
+void qcom_clear_bam_transaction(struct qcom_nand_controller *nandc)
+{
+	struct bam_transaction *bam_txn = nandc->bam_txn;
+
+	if (!nandc->props->supports_bam)
+		return;
+
+	memset(&bam_txn->bam_positions, 0, sizeof(bam_txn->bam_positions));
+	bam_txn->last_data_desc = NULL;
+
+	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(qcom_clear_bam_transaction);
+
+/**
+ * qcom_qpic_bam_dma_done() - Callback for DMA descriptor completion
+ * @data: data pointer
+ *
+ * This function is a callback for DMA descriptor completion
+ */
+void qcom_qpic_bam_dma_done(void *data)
+{
+	struct bam_transaction *bam_txn = data;
+
+	complete(&bam_txn->txn_done);
+}
+EXPORT_SYMBOL(qcom_qpic_bam_dma_done);
+
+/**
+ * qcom_nandc_dev_to_mem() - Check for dma sync for cpu or device
+ * @nandc: qpic nand controller
+ * @is_cpu: cpu or Device
+ *
+ * This function will check for dma sync for cpu or device
+ */
+inline void qcom_nandc_dev_to_mem(struct qcom_nand_controller *nandc, bool is_cpu)
+{
+	if (!nandc->props->supports_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(qcom_nandc_dev_to_mem);
+
+/**
+ * qcom_prepare_bam_async_desc() - Prepare DMA descriptor
+ * @nandc: qpic nand controller
+ * @chan: dma channel
+ * @flags: flags to control DMA descriptor preparation
+ *
+ * This function 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 qcom_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(qcom_prepare_bam_async_desc);
+
+/**
+ * qcom_prep_bam_dma_desc_cmd() - Prepares the command descriptor for BAM DMA
+ * @nandc: qpic nand controller
+ * @read: read or write type
+ * @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
+ *
+ * This function will prepares the command descriptor for BAM DMA
+ * which will be used for NAND register reads and writes.
+ */
+int qcom_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 = qcom_prepare_bam_async_desc(nandc, nandc->cmd_chan,
+							  DMA_PREP_FENCE | DMA_PREP_CMD);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(qcom_prep_bam_dma_desc_cmd);
+
+/**
+ * qcom_prep_bam_dma_desc_data() - Prepares the data descriptor for BAM DMA
+ * @nandc: qpic nand controller
+ * @read: read or write type
+ * @vaddr: virtual address of the buffer we want to write to
+ * @size: DMA transaction size in bytes
+ * @flags: flags to control DMA descriptor preparation
+ *
+ * This function will prepares the data descriptor for BAM DMA which
+ * will be used for NAND data reads and writes.
+ */
+int qcom_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 = qcom_prepare_bam_async_desc(nandc, nandc->tx_chan,
+							  DMA_PREP_INTERRUPT);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(qcom_prep_bam_dma_desc_data);
+
+/**
+ * qcom_prep_adm_dma_desc() - Prepare descriptor for adma
+ * @nandc: qpic nand controller
+ * @read: read or write type
+ * @reg_off: offset within the controller's data buffer
+ * @vaddr: virtual address of the buffer we want to write to
+ * @size: adm dma transaction size in bytes
+ * @flow_control: flow controller
+ *
+ * This function will prepare descriptor for adma
+ */
+int qcom_prep_adm_dma_desc(struct qcom_nand_controller *nandc, bool read,
+			   int reg_off, const void *vaddr, int size,
+			   bool flow_control)
+{
+	struct qcom_adm_peripheral_config periph_conf = {};
+	struct dma_async_tx_descriptor *dma_desc;
+	struct dma_slave_config slave_conf = {0};
+	enum dma_transfer_direction dir_eng;
+	struct desc_info *desc;
+	struct scatterlist *sgl;
+	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) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	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;
+}
+EXPORT_SYMBOL(qcom_prep_adm_dma_desc);
+
+/**
+ * qcom_read_reg_dma() - read a given number of registers to the reg_read_buf pointer
+ * @nandc: qpic nand controller
+ * @first: offset of the first register in the contiguous block
+ * @num_regs: number of registers to read
+ * @flags: flags to control DMA descriptor preparation
+ *
+ * This function will prepares a descriptor to read a given number of
+ * contiguous registers to the reg_read_buf pointer.
+ */
+int qcom_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->supports_bam)
+		return qcom_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 qcom_prep_adm_dma_desc(nandc, true, first, vaddr,
+				      num_regs * sizeof(u32), flow_control);
+}
+EXPORT_SYMBOL(qcom_read_reg_dma);
+
+/**
+ * qcom_write_reg_dma() - write a given number of registers
+ * @nandc: qpic nand controller
+ * @vaddr: contiguous memory from where register value will
+ *	   be written
+ * @first: offset of the first register in the contiguous block
+ * @num_regs: number of registers to write
+ * @flags: flags to control DMA descriptor preparation
+ *
+ * This function will prepares a descriptor to write a given number of
+ * contiguous registers
+ */
+int qcom_write_reg_dma(struct qcom_nand_controller *nandc, __le32 *vaddr,
+		       int first, int num_regs, unsigned int flags)
+{
+	bool flow_control = false;
+
+	if (first == NAND_EXEC_CMD)
+		flags |= NAND_BAM_NWD;
+
+	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->supports_bam)
+		return qcom_prep_bam_dma_desc_cmd(nandc, false, first, vaddr,
+						  num_regs, flags);
+
+	if (first == NAND_FLASH_CMD)
+		flow_control = true;
+
+	return qcom_prep_adm_dma_desc(nandc, false, first, vaddr,
+				      num_regs * sizeof(u32), flow_control);
+}
+EXPORT_SYMBOL(qcom_write_reg_dma);
+
+/**
+ * qcom_read_data_dma() - transfer data
+ * @nandc: qpic nand controller
+ * @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
+ *
+ * This function will prepares a DMA descriptor to transfer data from the
+ * controller's internal buffer to the buffer 'vaddr'
+ */
+int qcom_read_data_dma(struct qcom_nand_controller *nandc, int reg_off,
+		       const u8 *vaddr, int size, unsigned int flags)
+{
+	if (nandc->props->supports_bam)
+		return qcom_prep_bam_dma_desc_data(nandc, true, vaddr, size, flags);
+
+	return qcom_prep_adm_dma_desc(nandc, true, reg_off, vaddr, size, false);
+}
+EXPORT_SYMBOL(qcom_read_data_dma);
+
+/**
+ * qcom_write_data_dma() - transfer data
+ * @nandc: qpic nand controller
+ * @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
+ *
+ * This function will prepares a DMA descriptor to transfer data from
+ * 'vaddr' to the controller's internal buffer
+ */
+int qcom_write_data_dma(struct qcom_nand_controller *nandc, int reg_off,
+			const u8 *vaddr, int size, unsigned int flags)
+{
+	if (nandc->props->supports_bam)
+		return qcom_prep_bam_dma_desc_data(nandc, false, vaddr, size, flags);
+
+	return qcom_prep_adm_dma_desc(nandc, false, reg_off, vaddr, size, false);
+}
+EXPORT_SYMBOL(qcom_write_data_dma);
+
+/**
+ * qcom_submit_descs() - submit dma descriptor
+ * @nandc: qpic nand controller
+ *
+ * This function will submit all the prepared dma descriptor
+ * cmd or data descriptor
+ */
+int qcom_submit_descs(struct qcom_nand_controller *nandc)
+{
+	struct desc_info *desc, *n;
+	dma_cookie_t cookie = 0;
+	struct bam_transaction *bam_txn = nandc->bam_txn;
+	int ret = 0;
+
+	if (nandc->props->supports_bam) {
+		if (bam_txn->rx_sgl_pos > bam_txn->rx_sgl_start) {
+			ret = qcom_prepare_bam_async_desc(nandc, nandc->rx_chan, 0);
+			if (ret)
+				goto err_unmap_free_desc;
+		}
+
+		if (bam_txn->tx_sgl_pos > bam_txn->tx_sgl_start) {
+			ret = qcom_prepare_bam_async_desc(nandc, nandc->tx_chan,
+							  DMA_PREP_INTERRUPT);
+			if (ret)
+				goto err_unmap_free_desc;
+		}
+
+		if (bam_txn->cmd_sgl_pos > bam_txn->cmd_sgl_start) {
+			ret = qcom_prepare_bam_async_desc(nandc, nandc->cmd_chan,
+							  DMA_PREP_CMD);
+			if (ret)
+				goto err_unmap_free_desc;
+		}
+	}
+
+	list_for_each_entry(desc, &nandc->desc_list, node)
+		cookie = dmaengine_submit(desc->dma_desc);
+
+	if (nandc->props->supports_bam) {
+		bam_txn->last_cmd_desc->callback = qcom_qpic_bam_dma_done;
+		bam_txn->last_cmd_desc->callback_param = bam_txn;
+
+		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))
+			ret = -ETIMEDOUT;
+	} else {
+		if (dma_sync_wait(nandc->chan, cookie) != DMA_COMPLETE)
+			ret = -ETIMEDOUT;
+	}
+
+err_unmap_free_desc:
+	/*
+	 * Unmap the dma sg_list and free the desc allocated by both
+	 * qcom_prepare_bam_async_desc() and qcom_prep_adm_dma_desc() functions.
+	 */
+	list_for_each_entry_safe(desc, n, &nandc->desc_list, node) {
+		list_del(&desc->node);
+
+		if (nandc->props->supports_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);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(qcom_submit_descs);
+
+/**
+ * qcom_clear_read_regs() - reset the read register buffer
+ * @nandc: qpic nand controller
+ *
+ * This function reset the register read buffer for next NAND operation
+ */
+void qcom_clear_read_regs(struct qcom_nand_controller *nandc)
+{
+	nandc->reg_read_pos = 0;
+	qcom_nandc_dev_to_mem(nandc, false);
+}
+EXPORT_SYMBOL(qcom_clear_read_regs);
+
+/**
+ * qcom_nandc_unalloc() - unallocate qpic nand controller
+ * @nandc: qpic nand controller
+ *
+ * This function will unallocate memory alloacted for qpic nand controller
+ */
+void qcom_nandc_unalloc(struct qcom_nand_controller *nandc)
+{
+	if (nandc->props->supports_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);
+
+/**
+ * qcom_nandc_alloc() - Allocate qpic nand controller
+ * @nandc: qpic nand controller
+ *
+ * This function will allocate memory for qpic nand controller
+ */
+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->supports_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 transaction will be allocated with
+		 * maximum codeword size
+		 */
+		nandc->max_cwperpage = 1;
+		nandc->bam_txn = qcom_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);
+
+MODULE_DESCRIPTION("QPIC controller common api");
+MODULE_LICENSE("GPL");