[LEDE-DEV] [PATCH v3 4/6] ipq806x: Add support for custom data mapping in bam_dma dmaengine

Ram Chandra Jangir rjangir at codeaurora.org
Wed May 24 16:31:02 PDT 2017


This change adds a new function to support for preparing DMA descriptor
for custom data.

Signed-off-by: Ram Chandra Jangir <rjangir at codeaurora.org>
---

Changes since v2:
 *Splitted to individual patches

 ...gine-qcom-bam_dma-Add-custom-data-mapping.patch | 217 +++++++++++++++++++++
 1 file changed, 217 insertions(+)
 create mode 100644 target/linux/ipq806x/patches-4.9/862-dmaengine-qcom-bam_dma-Add-custom-data-mapping.patch

diff --git a/target/linux/ipq806x/patches-4.9/862-dmaengine-qcom-bam_dma-Add-custom-data-mapping.patch b/target/linux/ipq806x/patches-4.9/862-dmaengine-qcom-bam_dma-Add-custom-data-mapping.patch
new file mode 100644
index 0000000..3b26120
--- /dev/null
+++ b/target/linux/ipq806x/patches-4.9/862-dmaengine-qcom-bam_dma-Add-custom-data-mapping.patch
@@ -0,0 +1,217 @@
+From 5a7ccdf845d64b385affdcffaf2defbe9848be15 Mon Sep 17 00:00:00 2001
+From: Ram Chandra Jangir <rjangir at 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 at codeaurora.org>
+Signed-off-by: Ram Chandra Jangir <rjangir at 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
-- 
2.7.2




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