+From 5a7ccdf845d64b385affdcffaf2defbe9848be15 Mon Sep 17 00:00:00 2001
+From: Ram Chandra Jangir <rjangir@codeaurora.org>
+Date: Thu, 20 Apr 2017 10:39:00 +0530
+Subject: [PATCH] dmaengine: qcom: bam_dma: Add custom data mapping
+
+Add a new function to support for preparing DMA descriptor
+for custom data.
+
+Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
+Signed-off-by: Ram Chandra Jangir <rjangir@codeaurora.org>
+---
+ drivers/dma/qcom/bam_dma.c | 97 +++++++++++++++++++++++++++++++++++++---
+ include/linux/dma/qcom_bam_dma.h | 14 ++++++
+ include/linux/dmaengine.h | 14 ++++++
+ 3 files changed, 119 insertions(+), 6 deletions(-)
+
+diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c
+index 03c4eb3..bde8d70 100644
+--- a/drivers/dma/qcom/bam_dma.c
++++ b/drivers/dma/qcom/bam_dma.c
+@@ -49,6 +49,7 @@
+ #include <linux/clk.h>
+ #include <linux/dmaengine.h>
+ #include <linux/pm_runtime.h>
++#include <linux/dma/qcom_bam_dma.h>
+
+ #include "../dmaengine.h"
+ #include "../virt-dma.h"
+@@ -61,11 +62,6 @@ struct bam_desc_hw {
+
+ #define BAM_DMA_AUTOSUSPEND_DELAY 100
+
+-#define DESC_FLAG_INT BIT(15)
+-#define DESC_FLAG_EOT BIT(14)
+-#define DESC_FLAG_EOB BIT(13)
+-#define DESC_FLAG_NWD BIT(12)
+-
+ struct bam_async_desc {
+ struct virt_dma_desc vd;
+
+@@ -670,6 +666,93 @@ static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan,
+ }
+
+ /**
++ * bam_prep_dma_custom_mapping - Prep DMA descriptor from custom data
++ *
++ * @chan: dma channel
++ * @data: custom data
++ * @flags: DMA flags
++ */
++static struct dma_async_tx_descriptor *bam_prep_dma_custom_mapping(
++ struct dma_chan *chan,
++ void *data, unsigned long flags)
++{
++ struct bam_chan *bchan = to_bam_chan(chan);
++ struct bam_device *bdev = bchan->bdev;
++ struct bam_async_desc *async_desc;
++ struct qcom_bam_custom_data *desc_data = data;
++ u32 i;
++ struct bam_desc_hw *desc;
++ unsigned int num_alloc = 0;
++
++
++ if (!is_slave_direction(desc_data->dir)) {
++ dev_err(bdev->dev, "invalid dma direction\n");
++ return NULL;
++ }
++
++ /* calculate number of required entries */
++ for (i = 0; i < desc_data->sgl_cnt; i++)
++ num_alloc += DIV_ROUND_UP(
++ sg_dma_len(&desc_data->bam_sgl[i].sgl), BAM_FIFO_SIZE);
++
++ /* allocate enough room to accommodate the number of entries */
++ async_desc = kzalloc(sizeof(*async_desc) +
++ (num_alloc * sizeof(struct bam_desc_hw)), GFP_NOWAIT);
++
++ if (!async_desc)
++ goto err_out;
++
++ if (flags & DMA_PREP_FENCE)
++ async_desc->flags |= DESC_FLAG_NWD;
++
++ if (flags & DMA_PREP_INTERRUPT)
++ async_desc->flags |= DESC_FLAG_EOT;
++ else
++ async_desc->flags |= DESC_FLAG_INT;
++
++ async_desc->num_desc = num_alloc;
++ async_desc->curr_desc = async_desc->desc;
++ async_desc->dir = desc_data->dir;
++
++ /* fill in temporary descriptors */
++ desc = async_desc->desc;
++ for (i = 0; i < desc_data->sgl_cnt; i++) {
++ unsigned int remainder;
++ unsigned int curr_offset = 0;
++
++ remainder = sg_dma_len(&desc_data->bam_sgl[i].sgl);
++
++ do {
++ desc->addr = cpu_to_le32(
++ sg_dma_address(&desc_data->bam_sgl[i].sgl) +
++ curr_offset);
++
++ if (desc_data->bam_sgl[i].dma_flags)
++ desc->flags |= cpu_to_le16(
++ desc_data->bam_sgl[i].dma_flags);
++
++ if (remainder > BAM_FIFO_SIZE) {
++ desc->size = cpu_to_le16(BAM_FIFO_SIZE);
++ remainder -= BAM_FIFO_SIZE;
++ curr_offset += BAM_FIFO_SIZE;
++ } else {
++ desc->size = cpu_to_le16(remainder);
++ remainder = 0;
++ }
++
++ async_desc->length += desc->size;
++ desc++;
++ } while (remainder > 0);
++ }
++
++ return vchan_tx_prep(&bchan->vc, &async_desc->vd, flags);
++
++err_out:
++ kfree(async_desc);
++ return NULL;
++}
++
++/**
+ * bam_dma_terminate_all - terminate all transactions on a channel
+ * @bchan: bam dma channel
+ *
+@@ -960,7 +1043,7 @@ static void bam_start_dma(struct bam_chan *bchan)
+
+ /* set any special flags on the last descriptor */
+ if (async_desc->num_desc == async_desc->xfer_len)
+- desc[async_desc->xfer_len - 1].flags =
++ desc[async_desc->xfer_len - 1].flags |=
+ cpu_to_le16(async_desc->flags);
+ else
+ desc[async_desc->xfer_len - 1].flags |=
+@@ -1237,6 +1320,8 @@ static int bam_dma_probe(struct platform_device *pdev)
+ bdev->common.device_alloc_chan_resources = bam_alloc_chan;
+ bdev->common.device_free_chan_resources = bam_free_chan;
+ bdev->common.device_prep_slave_sg = bam_prep_slave_sg;
++ bdev->common.device_prep_dma_custom_mapping =
++ bam_prep_dma_custom_mapping;
+ bdev->common.device_config = bam_slave_config;
+ bdev->common.device_pause = bam_pause;
+ bdev->common.device_resume = bam_resume;
+diff --git a/include/linux/dma/qcom_bam_dma.h b/include/linux/dma/qcom_bam_dma.h
+index 7e87a85..7113c77 100644
+--- a/include/linux/dma/qcom_bam_dma.h
++++ b/include/linux/dma/qcom_bam_dma.h
+@@ -65,6 +65,19 @@ enum bam_command_type {
+ };
+
+ /*
++ * QCOM BAM DMA custom data
++ *
++ * @sgl_cnt: number of sgl in bam_sgl
++ * @dir: DMA data transfer direction
++ * @bam_sgl: BAM SGL pointer
++ */
++struct qcom_bam_custom_data {
++ u32 sgl_cnt;
++ enum dma_transfer_direction dir;
++ struct qcom_bam_sgl *bam_sgl;
++};
++
++/*
+ * qcom_bam_sg_init_table - Init QCOM BAM SGL
+ * @bam_sgl: bam sgl
+ * @nents: number of entries in bam sgl
+diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
+index cc535a4..627c125 100644
+--- a/include/linux/dmaengine.h
++++ b/include/linux/dmaengine.h
+@@ -692,6 +692,8 @@ struct dma_filter {
+ * be called after period_len bytes have been transferred.
+ * @device_prep_interleaved_dma: Transfer expression in a generic way.
+ * @device_prep_dma_imm_data: DMA's 8 byte immediate data to the dst address
++ * @device_prep_dma_custom_mapping: prepares a dma operation from dma driver
++ * specific custom data
+ * @device_config: Pushes a new configuration to a channel, return 0 or an error
+ * code
+ * @device_pause: Pauses any transfer happening on a channel. Returns
+@@ -783,6 +785,9 @@ struct dma_device {
+ struct dma_async_tx_descriptor *(*device_prep_dma_imm_data)(
+ struct dma_chan *chan, dma_addr_t dst, u64 data,
+ unsigned long flags);
++ struct dma_async_tx_descriptor *(*device_prep_dma_custom_mapping)(
++ struct dma_chan *chan, void *data,
++ unsigned long flags);
+
+ int (*device_config)(struct dma_chan *chan,
+ struct dma_slave_config *config);
+@@ -899,6 +904,15 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_sg(
+ src_sg, src_nents, flags);
+ }
+
++static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_custom_mapping(
++ struct dma_chan *chan,
++ void *data,
++ unsigned long flags)
++{
++ return chan->device->device_prep_dma_custom_mapping(chan, data,
++ flags);
++}
++
+ /**
+ * dmaengine_terminate_all() - Terminate all active DMA transfers
+ * @chan: The channel for which to terminate the transfers
+--
+2.7.2