* [PATCH V5] dmaengine: tegra: add dma driver
2012-04-23 12:11 [PATCH V2 0/4] ARM: tegra: enable ALS and proximity sensors Laxman Dewangan
2012-04-23 12:11 ` [PATCH V2 1/4] devicetree: Document Intersil Corporation vendor prefix Laxman Dewangan
@ 2012-04-23 12:11 ` Laxman Dewangan
[not found] ` <1335183097-21104-1-git-send-email-ldewangan-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
` (2 subsequent siblings)
4 siblings, 0 replies; 16+ messages in thread
From: Laxman Dewangan @ 2012-04-23 12:11 UTC (permalink / raw)
To: grant.likely, rob.herring, rob, linux, jic23, gregkh, swarren,
olof, devicetree-discuss, linux-doc, linux-kernel, linux-iio,
linux-tegra
Cc: Laxman Dewangan
Adding dmaengine based NVIDIA's Tegra APB dma driver.
This driver support the slave mode of data transfer from
peripheral to memory and vice versa.
The driver supports for the cyclic and non-cyclic mode
of data transfer.
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
---
Got initial comment from community on patch V1.
- Based on that, get rid of the tegra_dma.h header and move require
parameter in dma_slave_config of dmaengine.h.
- Change the desc allocation technique, allocating one by one.
- Corrected some typo.
- Already cover most of Stephen comments but final review was pending.
- Sending this patch for internal review again so that we will not loose
any comments.
drivers/dma/Kconfig | 14 +
drivers/dma/Makefile | 1 +
drivers/dma/tegra_dma.c | 1773 +++++++++++++++++++++++++++++++++++++++++++++
include/linux/dmaengine.h | 4 +
4 files changed, 1792 insertions(+), 0 deletions(-)
create mode 100644 drivers/dma/tegra_dma.c
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index ef378b5..611b10f 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -148,6 +148,20 @@ config TXX9_DMAC
Support the TXx9 SoC internal DMA controller. This can be
integrated in chips such as the Toshiba TX4927/38/39.
+config TEGRA_DMA
+ bool "NVIDIA Tegra DMA support"
+ depends on ARCH_TEGRA
+ select DMA_ENGINE
+ select REGMAP_MMIO
+ help
+ Support for the NVIDIA Tegra DMA controller driver. The dma
+ controller is having multiple dma channel which can be configured
+ for different peripherals like audio, UART, SPI, I2C etc which is
+ in APB bus.
+ This dma controller transfers data from memory to peripheral fifo
+ address or vice versa. It does not support memory to memory data
+ transfer.
+
config SH_DMAE
tristate "Renesas SuperH DMAC support"
depends on (SUPERH && SH_DMA) || (ARM && ARCH_SHMOBILE)
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 86b795b..3aaa63a 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_MXS_DMA) += mxs-dma.o
obj-$(CONFIG_TIMB_DMA) += timb_dma.o
obj-$(CONFIG_SIRF_DMA) += sirf-dma.o
obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o
+obj-$(CONFIG_TEGRA_DMA) += tegra_dma.o
obj-$(CONFIG_PL330_DMA) += pl330.o
obj-$(CONFIG_PCH_DMA) += pch_dma.o
obj-$(CONFIG_AMBA_PL08X) += amba-pl08x.o
diff --git a/drivers/dma/tegra_dma.c b/drivers/dma/tegra_dma.c
new file mode 100644
index 0000000..9bf415e
--- /dev/null
+++ b/drivers/dma/tegra_dma.c
@@ -0,0 +1,1773 @@
+/*
+ * DMA driver for Nvidia's Tegra apb dma controller.
+ *
+ * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include <mach/clk.h>
+#include "dmaengine.h"
+
+#define APB_DMA_GEN 0x0
+#define GEN_ENABLE BIT(31)
+
+#define APB_DMA_CNTRL 0x010
+#define APB_DMA_IRQ_MASK 0x01c
+#define APB_DMA_IRQ_MASK_SET 0x020
+
+/* CSR register */
+#define APB_DMA_CHAN_CSR 0x00
+#define CSR_ENB BIT(31)
+#define CSR_IE_EOC BIT(30)
+#define CSR_HOLD BIT(29)
+#define CSR_DIR BIT(28)
+#define CSR_ONCE BIT(27)
+#define CSR_FLOW BIT(21)
+#define CSR_REQ_SEL_SHIFT 16
+#define CSR_WCOUNT_MASK 0xFFFC
+
+/* STATUS register */
+#define APB_DMA_CHAN_STA 0x004
+#define STA_BUSY BIT(31)
+#define STA_ISE_EOC BIT(30)
+#define STA_HALT BIT(29)
+#define STA_PING_PONG BIT(28)
+#define STA_COUNT_SHIFT 2
+#define STA_COUNT_MASK 0xFFFC
+
+/* AHB memory address */
+#define APB_DMA_CHAN_AHB_PTR 0x010
+
+/* AHB sequence register */
+#define APB_DMA_CHAN_AHB_SEQ 0x14
+#define AHB_SEQ_INTR_ENB BIT(31)
+#define AHB_SEQ_BUS_WIDTH_SHIFT 28
+#define AHB_SEQ_BUS_WIDTH_8 (0 << AHB_SEQ_BUS_WIDTH_SHIFT)
+#define AHB_SEQ_BUS_WIDTH_16 (1 << AHB_SEQ_BUS_WIDTH_SHIFT)
+#define AHB_SEQ_BUS_WIDTH_32 (2 << AHB_SEQ_BUS_WIDTH_SHIFT)
+#define AHB_SEQ_BUS_WIDTH_64 (3 << AHB_SEQ_BUS_WIDTH_SHIFT)
+#define AHB_SEQ_BUS_WIDTH_128 (4 << AHB_SEQ_BUS_WIDTH_SHIFT)
+#define AHB_SEQ_DATA_SWAP BIT(27)
+#define AHB_SEQ_BURST_1 (4 << 24)
+#define AHB_SEQ_BURST_4 (5 << 24)
+#define AHB_SEQ_BURST_8 (6 << 24)
+#define AHB_SEQ_DBL_BUF BIT(19)
+#define AHB_SEQ_WRAP_SHIFT 16
+#define AHB_SEQ_WRAP_NONE 0
+
+/* APB address */
+#define APB_DMA_CHAN_APB_PTR 0x018
+
+/* APB sequence register */
+#define APB_DMA_CHAN_APB_SEQ 0x01c
+#define APB_SEQ_BUS_WIDTH_SHIFT 28
+#define APB_SEQ_BUS_WIDTH_8 (0 << APB_SEQ_BUS_WIDTH_SHIFT)
+#define APB_SEQ_BUS_WIDTH_16 (1 << APB_SEQ_BUS_WIDTH_SHIFT)
+#define APB_SEQ_BUS_WIDTH_32 (2 << APB_SEQ_BUS_WIDTH_SHIFT)
+#define APB_SEQ_BUS_WIDTH_64 (3 << APB_SEQ_BUS_WIDTH_SHIFT)
+#define APB_SEQ_BUS_WIDTH_128 (4 << APB_SEQ_BUS_WIDTH_SHIFT)
+#define APB_SEQ_DATA_SWAP BIT(27)
+#define APB_SEQ_WRAP_SHIFT 16
+#define APB_SEQ_WRAP_WORD_1 (1 << APB_SEQ_WRAP_SHIFT)
+
+/*
+ * If any burst is in flight and dma paused then this is the time to complete
+ * on-flight burst and update dma status register.
+ */
+#define DMA_BUSRT_COMPLETE_TIME 20
+
+/* Channel base address offset from APBDMA base address */
+#define DMA_CHANNEL_BASE_ADDRESS_OFFSET 0x1000
+
+/* DMA channel register space size */
+#define DMA_CHANNEL_REGISTER_SIZE 0x20
+
+/*
+ * Initial number of descriptors to allocate for each channel during
+ * allocation. More descriptors will be allocated dynamically if
+ * client needs it.
+ */
+#define DMA_NR_DESCS_PER_CHANNEL 4
+#define DMA_NR_REQ_PER_DESC 8
+
+struct tegra_dma;
+
+/*
+ * tegra_dma_chip_data Tegra chip specific dma data
+ * @nr_channels: Number of channels available in the controller.
+ * @max_dma_count: Maximum dma transfer count supported by dma controller.
+ */
+struct tegra_dma_chip_data {
+ int nr_channels;
+ int max_dma_count;
+};
+
+/*
+ * dma_transfer_mode: Different dma transfer mode.
+ * DMA_MODE_ONCE: Dma transfer the configured buffer once and at the end of
+ * transfer, dma stops automatically and generates interrupt
+ * if enabled. SW need to reprogram dma for next transfer.
+ * DMA_MODE_CYCLE: Dma keeps transferring the same buffer again and again
+ * until dma stopped explicitly by SW or another buffer configured.
+ * After transfer completes, dma again starts transfer from
+ * beginning of buffer without sw intervention. If any new
+ * address/size is configured during buffer transfer then
+ * dma start transfer with new configuration otherwise it
+ * will keep transferring with old configuration. It also
+ * generates the interrupt after buffer transfer completes.
+ * DMA_MODE_CYCLE_HALF_NOTIFY: In this mode dma keeps transferring the buffer
+ * into two folds. This is kind of ping-pong buffer where both
+ * buffer size should be same. Dma completes the one buffer,
+ * generates interrupt and keep transferring the next buffer
+ * whose address start just next to first buffer. At the end of
+ * second buffer transfer, dma again generates interrupt and
+ * keep transferring of the data from starting of first buffer.
+ * If sw wants to change the address/size of the buffer then
+ * it needs to change only when dma transferring the second
+ * half of buffer. In dma configuration, it only need to
+ * configure starting of first buffer and size of first buffer.
+ * Dma hw assumes that striating address of second buffer is just
+ * next to end of first buffer and size is same as the first
+ * buffer.
+ */
+enum dma_transfer_mode {
+ DMA_MODE_NONE,
+ DMA_MODE_ONCE,
+ DMA_MODE_CYCLE,
+ DMA_MODE_CYCLE_HALF_NOTIFY,
+};
+
+/* Dma channel registers */
+struct tegra_dma_channel_regs {
+ unsigned long csr;
+ unsigned long ahb_ptr;
+ unsigned long apb_ptr;
+ unsigned long ahb_seq;
+ unsigned long apb_seq;
+};
+
+/*
+ * tegra_dma_sg_req: Dma request details to configure hardware. This
+ * contains the details for one transfer to configure dma hw.
+ * The client's request for data transfer can be broken into multiple
+ * sub-transfer as per requester details and hw support.
+ * This sub transfer get added in the list of transfer and point to Tegra
+ * dma descriptor which manages the transfer details.
+ */
+struct tegra_dma_sg_req {
+ struct tegra_dma_channel_regs ch_regs;
+ int req_len;
+ bool configured;
+ bool last_sg;
+ bool half_done;
+ struct list_head node;
+ struct tegra_dma_desc *dma_desc;
+};
+
+/*
+ * tegra_dma_desc: Tegra dma descriptors which manages the client requests.
+ * This descriptor keep track of transfer status, callbacks and request
+ * counts etc.
+ */
+struct tegra_dma_desc {
+ int bytes_requested;
+ int bytes_transferred;
+ enum dma_status dma_status;
+ struct dma_async_tx_descriptor txd;
+ struct list_head node;
+ struct list_head tx_list;
+ struct list_head cb_node;
+ bool ack_reqd;
+ bool cb_due;
+ dma_cookie_t cookie;
+};
+
+struct tegra_dma_channel;
+
+typedef void (*dma_isr_handler)(struct tegra_dma_channel *tdc,
+ bool to_terminate);
+
+/* tegra_dma_channel: Channel specific information */
+struct tegra_dma_channel {
+ bool config_init;
+ int id;
+ int irq;
+ unsigned long chan_base_offset;
+ spinlock_t lock;
+ bool busy;
+ enum dma_transfer_mode dma_mode;
+ int descs_allocated;
+ struct dma_chan dma_chan;
+ struct tegra_dma *tdma;
+
+ /* Different lists for managing the requests */
+ struct list_head free_sg_req;
+ struct list_head pending_sg_req;
+ struct list_head free_dma_desc;
+ struct list_head wait_ack_dma_desc;
+ struct list_head cb_desc;
+
+ /* isr handler and tasklet for bottom half of isr handling */
+ dma_isr_handler isr_handler;
+ struct tasklet_struct tasklet;
+ dma_async_tx_callback callback;
+ void *callback_param;
+
+ /* Channel-slave specific configuration */
+ struct dma_slave_config dma_sconfig;
+};
+
+/* tegra_dma: Tegra dma specific information */
+struct tegra_dma {
+ struct dma_device dma_dev;
+ struct device *dev;
+ struct clk *dma_clk;
+ spinlock_t global_lock;
+ void __iomem *base_addr;
+ struct regmap *regmap_dma;
+ struct tegra_dma_chip_data chip_data;
+
+ /* Last member of the structure */
+ struct tegra_dma_channel channels[0];
+};
+
+static inline void tdma_write(struct tegra_dma *tdma, u32 reg, u32 val)
+{
+ regmap_write(tdma->regmap_dma, reg, val);
+}
+
+static inline u32 tdma_read(struct tegra_dma *tdma, u32 reg)
+{
+ u32 val;
+ regmap_read(tdma->regmap_dma, reg, &val);
+ return val;
+}
+
+static inline void tdc_write(struct tegra_dma_channel *tdc,
+ u32 reg, u32 val)
+{
+ regmap_write(tdc->tdma->regmap_dma, tdc->chan_base_offset + reg, val);
+}
+
+static inline u32 tdc_read(struct tegra_dma_channel *tdc, u32 reg)
+{
+ u32 val;
+ regmap_read(tdc->tdma->regmap_dma, tdc->chan_base_offset + reg, &val);
+ return val;
+}
+
+static inline struct tegra_dma_channel *to_tegra_dma_chan(struct dma_chan *dc)
+{
+ return container_of(dc, struct tegra_dma_channel, dma_chan);
+}
+
+static inline struct tegra_dma_desc *txd_to_tegra_dma_desc(
+ struct dma_async_tx_descriptor *td)
+{
+ return container_of(td, struct tegra_dma_desc, txd);
+}
+
+static inline struct device *tdc2dev(struct tegra_dma_channel *tdc)
+{
+ return &tdc->dma_chan.dev->device;
+}
+
+static dma_cookie_t tegra_dma_tx_submit(struct dma_async_tx_descriptor *tx);
+
+static int allocate_tegra_desc(struct tegra_dma_channel *tdc,
+ int ndma_desc, int nsg_req)
+{
+ int i;
+ struct tegra_dma_desc *dma_desc;
+ struct tegra_dma_sg_req *sg_req;
+ struct dma_chan *dc = &tdc->dma_chan;
+ struct list_head dma_desc_list;
+ struct list_head sg_req_list;
+ unsigned long flags;
+
+ INIT_LIST_HEAD(&dma_desc_list);
+ INIT_LIST_HEAD(&sg_req_list);
+
+ /* Initialize dma descriptors */
+ for (i = 0; i < ndma_desc; ++i) {
+ dma_desc = kzalloc(sizeof(struct tegra_dma_desc), GFP_KERNEL);
+ if (!dma_desc) {
+ dev_err(tdc2dev(tdc),
+ "%s(): Memory allocation fails\n", __func__);
+ goto fail_alloc;
+ }
+
+ dma_async_tx_descriptor_init(&dma_desc->txd, dc);
+ dma_desc->txd.tx_submit = tegra_dma_tx_submit;
+ dma_desc->txd.flags = DMA_CTRL_ACK;
+ list_add_tail(&dma_desc->node, &dma_desc_list);
+ }
+
+ /* Initialize req descriptors */
+ for (i = 0; i < nsg_req; ++i) {
+ sg_req = kzalloc(sizeof(struct tegra_dma_sg_req), GFP_KERNEL);
+ if (!sg_req) {
+ dev_err(tdc2dev(tdc),
+ "%s(): Memory allocation fails\n", __func__);
+ goto fail_alloc;
+ }
+ list_add_tail(&sg_req->node, &sg_req_list);
+ }
+
+ spin_lock_irqsave(&tdc->lock, flags);
+ if (ndma_desc) {
+ tdc->descs_allocated += ndma_desc;
+ list_splice(&dma_desc_list, &tdc->free_dma_desc);
+ }
+
+ if (nsg_req)
+ list_splice(&sg_req_list, &tdc->free_sg_req);
+ spin_unlock_irqrestore(&tdc->lock, flags);
+ return tdc->descs_allocated;
+
+fail_alloc:
+ while (!list_empty(&dma_desc_list)) {
+ dma_desc = list_first_entry(&dma_desc_list,
+ typeof(*dma_desc), node);
+ list_del(&dma_desc->node);
+ }
+
+ while (!list_empty(&sg_req_list)) {
+ sg_req = list_first_entry(&sg_req_list, typeof(*sg_req), node);
+ list_del(&sg_req->node);
+ }
+ return 0;
+}
+
+/* Get dma desc from free list, if not there then allocate it */
+static struct tegra_dma_desc *tegra_dma_desc_get(struct tegra_dma_channel *tdc)
+{
+ struct tegra_dma_desc *dma_desc = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&tdc->lock, flags);
+
+ /* Check from free list desc */
+ if (!list_empty(&tdc->free_dma_desc)) {
+ dma_desc = list_first_entry(&tdc->free_dma_desc,
+ typeof(*dma_desc), node);
+ list_del(&dma_desc->node);
+ goto end;
+ }
+
+ /*
+ * Check list with desc which are waiting for ack, may be it
+ * got acked from client.
+ */
+ if (!list_empty(&tdc->wait_ack_dma_desc)) {
+ list_for_each_entry(dma_desc, &tdc->wait_ack_dma_desc, node) {
+ if (async_tx_test_ack(&dma_desc->txd)) {
+ list_del(&dma_desc->node);
+ goto end;
+ }
+ }
+ }
+
+ /* There is no free desc, allocate it */
+ spin_unlock_irqrestore(&tdc->lock, flags);
+ dev_dbg(tdc2dev(tdc),
+ "Allocating more descriptors for channel %d\n", tdc->id);
+ allocate_tegra_desc(tdc, DMA_NR_DESCS_PER_CHANNEL,
+ DMA_NR_DESCS_PER_CHANNEL * DMA_NR_REQ_PER_DESC);
+ spin_lock_irqsave(&tdc->lock, flags);
+ if (list_empty(&tdc->free_dma_desc))
+ goto end;
+
+ dma_desc = list_first_entry(&tdc->free_dma_desc,
+ typeof(*dma_desc), node);
+ list_del(&dma_desc->node);
+end:
+ spin_unlock_irqrestore(&tdc->lock, flags);
+ return dma_desc;
+}
+
+static void tegra_dma_desc_put(struct tegra_dma_channel *tdc,
+ struct tegra_dma_desc *dma_desc)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&tdc->lock, flags);
+ if (!list_empty(&dma_desc->tx_list))
+ list_splice_init(&dma_desc->tx_list, &tdc->free_sg_req);
+ list_add_tail(&dma_desc->node, &tdc->free_dma_desc);
+ spin_unlock_irqrestore(&tdc->lock, flags);
+}
+
+static void tegra_dma_desc_done_locked(struct tegra_dma_channel *tdc,
+ struct tegra_dma_desc *dma_desc)
+{
+ if (dma_desc->ack_reqd)
+ list_add_tail(&dma_desc->node, &tdc->wait_ack_dma_desc);
+ else
+ list_add_tail(&dma_desc->node, &tdc->free_dma_desc);
+}
+
+static struct tegra_dma_sg_req *tegra_dma_sg_req_get(
+ struct tegra_dma_channel *tdc)
+{
+ struct tegra_dma_sg_req *sg_req = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&tdc->lock, flags);
+ if (list_empty(&tdc->free_sg_req)) {
+ spin_unlock_irqrestore(&tdc->lock, flags);
+ dev_dbg(tdc2dev(tdc),
+ "Reallocating sg_req for channel %d\n", tdc->id);
+ allocate_tegra_desc(tdc, 0,
+ DMA_NR_DESCS_PER_CHANNEL * DMA_NR_REQ_PER_DESC);
+ spin_lock_irqsave(&tdc->lock, flags);
+ if (list_empty(&tdc->free_sg_req)) {
+ dev_dbg(tdc2dev(tdc),
+ "Not found free sg_req for channel %d\n", tdc->id);
+ goto end;
+ }
+ }
+
+ sg_req = list_first_entry(&tdc->free_sg_req, typeof(*sg_req), node);
+ list_del(&sg_req->node);
+end:
+ spin_unlock_irqrestore(&tdc->lock, flags);
+ return sg_req;
+}
+
+static int tegra_dma_slave_config(struct dma_chan *dc,
+ struct dma_slave_config *sconfig)
+{
+ struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
+
+ if (!list_empty(&tdc->pending_sg_req)) {
+ dev_err(tdc2dev(tdc),
+ "dma requests are pending, cannot take new configuration");
+ return -EBUSY;
+ }
+
+ memcpy(&tdc->dma_sconfig, sconfig, sizeof(*sconfig));
+ tdc->config_init = true;
+ return 0;
+}
+
+static void tegra_dma_pause(struct tegra_dma_channel *tdc,
+ bool wait_for_burst_complete)
+{
+ struct tegra_dma *tdma = tdc->tdma;
+ spin_lock(&tdma->global_lock);
+ tdma_write(tdma, APB_DMA_GEN, 0);
+ if (wait_for_burst_complete)
+ udelay(DMA_BUSRT_COMPLETE_TIME);
+}
+
+static void tegra_dma_resume(struct tegra_dma_channel *tdc)
+{
+ struct tegra_dma *tdma = tdc->tdma;
+ tdma_write(tdma, APB_DMA_GEN, GEN_ENABLE);
+ spin_unlock(&tdma->global_lock);
+}
+
+static void tegra_dma_stop(struct tegra_dma_channel *tdc)
+{
+ u32 csr;
+ u32 status;
+
+ /* Disable interrupts */
+ csr = tdc_read(tdc, APB_DMA_CHAN_CSR);
+ csr &= ~CSR_IE_EOC;
+ tdc_write(tdc, APB_DMA_CHAN_CSR, csr);
+
+ /* Disable dma */
+ csr &= ~CSR_ENB;
+ tdc_write(tdc, APB_DMA_CHAN_CSR, csr);
+
+ /* Clear interrupt status if it is there */
+ status = tdc_read(tdc, APB_DMA_CHAN_STA);
+ if (status & STA_ISE_EOC) {
+ dev_dbg(tdc2dev(tdc), "%s():clearing interrupt\n", __func__);
+ tdc_write(tdc, APB_DMA_CHAN_STA, status);
+ }
+ tdc->busy = false;
+}
+
+static void tegra_dma_start(struct tegra_dma_channel *tdc,
+ struct tegra_dma_sg_req *sg_req)
+{
+ struct tegra_dma_channel_regs *ch_regs = &sg_req->ch_regs;
+ unsigned long csr = ch_regs->csr;
+
+ tdc_write(tdc, APB_DMA_CHAN_CSR, csr);
+ tdc_write(tdc, APB_DMA_CHAN_APB_SEQ, ch_regs->apb_seq);
+ tdc_write(tdc, APB_DMA_CHAN_APB_PTR, ch_regs->apb_ptr);
+ tdc_write(tdc, APB_DMA_CHAN_AHB_SEQ, ch_regs->ahb_seq);
+ tdc_write(tdc, APB_DMA_CHAN_AHB_PTR, ch_regs->ahb_ptr);
+
+ /* Dump the configuration register if verbose mode enabled */
+ dev_vdbg(tdc2dev(tdc),
+ "%s(): csr: 0x%08lx\n", __func__, ch_regs->csr);
+ dev_vdbg(tdc2dev(tdc),
+ "%s(): apbseq: 0x%08lx\n", __func__, ch_regs->apb_seq);
+ dev_vdbg(tdc2dev(tdc),
+ "%s(): apbptr: 0x%08lx\n", __func__, ch_regs->apb_ptr);
+ dev_vdbg(tdc2dev(tdc),
+ "%s(): ahbseq: 0x%08lx\n", __func__, ch_regs->ahb_seq);
+ dev_vdbg(tdc2dev(tdc),
+ "%s(): ahbptr: 0x%08lx\n", __func__, ch_regs->ahb_ptr);
+
+ /* Start dma */
+ csr |= CSR_ENB;
+ tdc_write(tdc, APB_DMA_CHAN_CSR, csr);
+}
+
+static void tegra_dma_configure_for_next(struct tegra_dma_channel *tdc,
+ struct tegra_dma_sg_req *nsg_req)
+{
+ unsigned long status;
+
+ /*
+ * The dma controller reloads the new configuration for next transfer
+ * after last burst of current transfer completes.
+ * If there is no IEC status then this makes sure that last burst
+ * has not be completed. There may be case that last burst is on
+ * flight and so it can complete but because dma is paused, it
+ * will not generates interrupt as well as not reload the new
+ * configuration.
+ * If there is already IEC status then interrupt handler need to
+ * load new configuration.
+ */
+ tegra_dma_pause(tdc, false);
+ status = tdc_read(tdc, APB_DMA_CHAN_STA);
+
+ /*
+ * If interrupt is pending then do nothing as the ISR will handle
+ * the programing for new request.
+ */
+ if (status & STA_ISE_EOC) {
+ dev_err(tdc2dev(tdc),
+ "Skipping new configuration as interrupt is pending\n");
+ goto exit_config;
+ }
+
+ /* Safe to program new configuration */
+ tdc_write(tdc, APB_DMA_CHAN_APB_PTR, nsg_req->ch_regs.apb_ptr);
+ tdc_write(tdc, APB_DMA_CHAN_AHB_PTR, nsg_req->ch_regs.ahb_ptr);
+ tdc_write(tdc, APB_DMA_CHAN_CSR, nsg_req->ch_regs.csr | CSR_ENB);
+ nsg_req->configured = true;
+
+exit_config:
+ tegra_dma_resume(tdc);
+}
+
+static void tdc_start_head_req(struct tegra_dma_channel *tdc)
+{
+ struct tegra_dma_sg_req *sg_req;
+
+ if (list_empty(&tdc->pending_sg_req))
+ return;
+
+ sg_req = list_first_entry(&tdc->pending_sg_req,
+ typeof(*sg_req), node);
+ tegra_dma_start(tdc, sg_req);
+ sg_req->configured = true;
+ tdc->busy = true;
+}
+
+static void tdc_configure_next_head_desc(struct tegra_dma_channel *tdc)
+{
+ struct tegra_dma_sg_req *hsgreq;
+ struct tegra_dma_sg_req *hnsgreq;
+
+ if (list_empty(&tdc->pending_sg_req))
+ return;
+
+ hsgreq = list_first_entry(&tdc->pending_sg_req, typeof(*hsgreq), node);
+ if (!list_is_last(&hsgreq->node, &tdc->pending_sg_req)) {
+ hnsgreq = list_first_entry(&hsgreq->node,
+ typeof(*hnsgreq), node);
+ tegra_dma_configure_for_next(tdc, hnsgreq);
+ }
+}
+
+static inline int get_current_xferred_count(struct tegra_dma_channel *tdc,
+ struct tegra_dma_sg_req *sg_req, unsigned long status)
+{
+ return sg_req->req_len - ((status & STA_COUNT_MASK) + 4);
+}
+
+static void tegra_dma_abort_all(struct tegra_dma_channel *tdc)
+{
+ struct tegra_dma_sg_req *sgreq;
+ struct tegra_dma_desc *dma_desc;
+ while (!list_empty(&tdc->pending_sg_req)) {
+ sgreq = list_first_entry(&tdc->pending_sg_req,
+ typeof(*sgreq), node);
+ list_del(&sgreq->node);
+ list_add_tail(&sgreq->node, &tdc->free_sg_req);
+ if (sgreq->last_sg) {
+ dma_desc = sgreq->dma_desc;
+ dma_desc->dma_status = DMA_ERROR;
+ tegra_dma_desc_done_locked(tdc, dma_desc);
+
+ /* Add in cb list if it is not there. */
+ if (!dma_desc->cb_due) {
+ list_add_tail(&dma_desc->cb_node,
+ &tdc->cb_desc);
+ dma_desc->cb_due = true;
+ }
+ dma_cookie_complete(&dma_desc->txd);
+ }
+ }
+ tdc->dma_mode = DMA_MODE_NONE;
+}
+
+static bool handle_continuous_head_request(struct tegra_dma_channel *tdc,
+ struct tegra_dma_sg_req *last_sg_req, bool to_terminate)
+{
+ struct tegra_dma_sg_req *hsgreq = NULL;
+
+ if (list_empty(&tdc->pending_sg_req)) {
+ dev_err(tdc2dev(tdc),
+ "%s(): Dma is running without any req list\n",
+ __func__);
+ tegra_dma_stop(tdc);
+ return false;
+ }
+
+ /*
+ * Check that head req on list should be in flight.
+ * If it is not in flight then abort transfer as
+ * transfer looping can not continue.
+ */
+ hsgreq = list_first_entry(&tdc->pending_sg_req, typeof(*hsgreq), node);
+ if (!hsgreq->configured) {
+ tegra_dma_stop(tdc);
+ dev_err(tdc2dev(tdc),
+ "Error in dma transfer loop, aborting dma\n");
+ tegra_dma_abort_all(tdc);
+ return false;
+ }
+
+ /* Configure next request in single buffer mode */
+ if (!to_terminate && (tdc->dma_mode == DMA_MODE_CYCLE))
+ tdc_configure_next_head_desc(tdc);
+ return true;
+}
+
+static void handle_once_dma_done(struct tegra_dma_channel *tdc,
+ bool to_terminate)
+{
+ struct tegra_dma_sg_req *sgreq;
+ struct tegra_dma_desc *dma_desc;
+
+ tdc->busy = false;
+ sgreq = list_first_entry(&tdc->pending_sg_req, typeof(*sgreq), node);
+ dma_desc = sgreq->dma_desc;
+ dma_desc->bytes_transferred += sgreq->req_len;
+
+ list_del(&sgreq->node);
+ if (sgreq->last_sg) {
+ dma_cookie_complete(&dma_desc->txd);
+ list_add_tail(&dma_desc->cb_node, &tdc->cb_desc);
+ dma_desc->cb_due = true;
+ tegra_dma_desc_done_locked(tdc, dma_desc);
+ }
+ list_add_tail(&sgreq->node, &tdc->free_sg_req);
+
+ /* Do not start dma if it is going to be terminate */
+ if (to_terminate || list_empty(&tdc->pending_sg_req))
+ return;
+
+ tdc_start_head_req(tdc);
+ return;
+}
+
+static void handle_cont_sngl_cycle_dma_done(struct tegra_dma_channel *tdc,
+ bool to_terminate)
+{
+ struct tegra_dma_sg_req *sgreq;
+ struct tegra_dma_desc *dma_desc;
+ bool st;
+
+ sgreq = list_first_entry(&tdc->pending_sg_req, typeof(*sgreq), node);
+ dma_desc = sgreq->dma_desc;
+ dma_desc->bytes_transferred += sgreq->req_len;
+
+ /* Callback need to be call */
+ list_add_tail(&dma_desc->cb_node, &tdc->cb_desc);
+ dma_desc->cb_due = true;
+
+ /* If not last req then put at end of pending list */
+ if (!list_is_last(&sgreq->node, &tdc->pending_sg_req)) {
+ list_del(&sgreq->node);
+ list_add_tail(&sgreq->node, &tdc->pending_sg_req);
+ sgreq->configured = false;
+ st = handle_continuous_head_request(tdc, sgreq, to_terminate);
+ if (!st)
+ dma_desc->dma_status = DMA_ERROR;
+ }
+ return;
+}
+
+static void handle_cont_dbl_cycle_dma_done(struct tegra_dma_channel *tdc,
+ bool to_terminate)
+{
+ struct tegra_dma_sg_req *hsgreq;
+ struct tegra_dma_sg_req *hnsgreq;
+ struct tegra_dma_desc *dma_desc;
+
+ hsgreq = list_first_entry(&tdc->pending_sg_req, typeof(*hsgreq), node);
+ dma_desc = hsgreq->dma_desc;
+ dma_desc->bytes_transferred += hsgreq->req_len;
+
+ if (!hsgreq->half_done) {
+ if (!list_is_last(hsgreq->node.next, &tdc->pending_sg_req) &&
+ !to_terminate) {
+ hnsgreq = list_first_entry(&hsgreq->node,
+ typeof(*hnsgreq), node);
+ tegra_dma_configure_for_next(tdc, hnsgreq);
+ }
+ hsgreq->half_done = true;
+ list_add_tail(&dma_desc->cb_node, &tdc->cb_desc);
+ dma_desc->cb_due = true;
+ } else {
+ hsgreq->half_done = false;
+ list_add_tail(&dma_desc->cb_node, &tdc->cb_desc);
+ dma_desc->cb_due = true;
+
+ /*
+ * If this is not last entry then put the req in end of
+ * list for next cycle.
+ */
+ if (!list_is_last(hsgreq->node.next, &tdc->pending_sg_req)) {
+ list_del(&hsgreq->node);
+ list_add_tail(&hsgreq->node, &tdc->pending_sg_req);
+ hsgreq->configured = false;
+ }
+ }
+ return;
+}
+
+static void tegra_dma_tasklet(unsigned long data)
+{
+ struct tegra_dma_channel *tdc = (struct tegra_dma_channel *)data;
+ unsigned long flags;
+ dma_async_tx_callback callback = NULL;
+ void *callback_param = NULL;
+ struct tegra_dma_desc *dma_desc;
+ struct list_head cb_dma_desc_list;
+
+ INIT_LIST_HEAD(&cb_dma_desc_list);
+ spin_lock_irqsave(&tdc->lock, flags);
+ if (list_empty(&tdc->cb_desc)) {
+ spin_unlock_irqrestore(&tdc->lock, flags);
+ return;
+ }
+ list_splice_init(&tdc->cb_desc, &cb_dma_desc_list);
+ spin_unlock_irqrestore(&tdc->lock, flags);
+
+ while (!list_empty(&cb_dma_desc_list)) {
+ dma_desc = list_first_entry(&cb_dma_desc_list,
+ typeof(*dma_desc), cb_node);
+ list_del(&dma_desc->cb_node);
+
+ callback = dma_desc->txd.callback;
+ callback_param = dma_desc->txd.callback_param;
+ dma_desc->cb_due = false;
+ if (callback)
+ callback(callback_param);
+ }
+}
+
+static irqreturn_t tegra_dma_isr(int irq, void *dev_id)
+{
+ struct tegra_dma_channel *tdc = dev_id;
+ unsigned long status;
+ unsigned long flags;
+
+ spin_lock_irqsave(&tdc->lock, flags);
+
+ status = tdc_read(tdc, APB_DMA_CHAN_STA);
+ if (status & STA_ISE_EOC) {
+ tdc_write(tdc, APB_DMA_CHAN_STA, status);
+ if (!list_empty(&tdc->cb_desc)) {
+ dev_err(tdc2dev(tdc),
+ "Int before tasklet handled, Stopping DMA %d\n",
+ tdc->id);
+ tegra_dma_stop(tdc);
+ tdc->isr_handler(tdc, true);
+ tegra_dma_abort_all(tdc);
+ /* Schedule tasklet to make callback */
+ tasklet_schedule(&tdc->tasklet);
+ goto end;
+ }
+ tdc->isr_handler(tdc, false);
+ tasklet_schedule(&tdc->tasklet);
+ } else {
+ dev_info(tdc2dev(tdc),
+ "Interrupt is already handled %d status 0x%08lx\n",
+ tdc->id, status);
+ }
+
+end:
+ spin_unlock_irqrestore(&tdc->lock, flags);
+ return IRQ_HANDLED;
+}
+
+static dma_cookie_t tegra_dma_tx_submit(struct dma_async_tx_descriptor *txd)
+{
+ struct tegra_dma_desc *dma_desc = txd_to_tegra_dma_desc(txd);
+ struct tegra_dma_channel *tdc = to_tegra_dma_chan(txd->chan);
+ unsigned long flags;
+ dma_cookie_t cookie;
+
+ spin_lock_irqsave(&tdc->lock, flags);
+ dma_desc->dma_status = DMA_IN_PROGRESS;
+ cookie = dma_cookie_assign(&dma_desc->txd);
+ dma_desc->cookie = dma_desc->txd.cookie;
+ list_splice_tail_init(&dma_desc->tx_list, &tdc->pending_sg_req);
+ spin_unlock_irqrestore(&tdc->lock, flags);
+ return cookie;
+}
+
+static void tegra_dma_issue_pending(struct dma_chan *dc)
+{
+ struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
+ unsigned long flags;
+
+ spin_lock_irqsave(&tdc->lock, flags);
+ if (list_empty(&tdc->pending_sg_req)) {
+ dev_err(tdc2dev(tdc),
+ "No requests for channel %d\n", tdc->id);
+ goto end;
+ }
+ if (!tdc->busy) {
+ tdc_start_head_req(tdc);
+
+ /* Continuous single mode: Configure next req */
+ if (DMA_MODE_CYCLE) {
+ /*
+ * Wait for 1 burst time for configure dma for
+ * next transfer.
+ */
+ udelay(DMA_BUSRT_COMPLETE_TIME);
+ tdc_configure_next_head_desc(tdc);
+ }
+ }
+end:
+ spin_unlock_irqrestore(&tdc->lock, flags);
+ return;
+}
+
+static void tegra_dma_terminate_all(struct dma_chan *dc)
+{
+ struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
+ struct tegra_dma_sg_req *sgreq;
+ struct tegra_dma_desc *dma_desc;
+ unsigned long flags;
+ unsigned long status;
+ struct list_head new_list;
+ dma_async_tx_callback callback = NULL;
+ void *callback_param = NULL;
+ struct list_head cb_dma_desc_list;
+ bool was_busy;
+
+ INIT_LIST_HEAD(&new_list);
+ INIT_LIST_HEAD(&cb_dma_desc_list);
+
+ spin_lock_irqsave(&tdc->lock, flags);
+ if (list_empty(&tdc->pending_sg_req)) {
+ spin_unlock_irqrestore(&tdc->lock, flags);
+ return;
+ }
+
+ if (!tdc->busy) {
+ list_splice_init(&tdc->cb_desc, &cb_dma_desc_list);
+ goto skip_dma_stop;
+ }
+
+ /* Pause dma before checking the queue status */
+ tegra_dma_pause(tdc, true);
+
+ status = tdc_read(tdc, APB_DMA_CHAN_STA);
+ if (status & STA_ISE_EOC) {
+ dev_dbg(tdc2dev(tdc), "%s():handling isr\n", __func__);
+ tdc->isr_handler(tdc, true);
+ status = tdc_read(tdc, APB_DMA_CHAN_STA);
+ }
+ list_splice_init(&tdc->cb_desc, &cb_dma_desc_list);
+
+ was_busy = tdc->busy;
+ tegra_dma_stop(tdc);
+ if (!list_empty(&tdc->pending_sg_req) && was_busy) {
+ sgreq = list_first_entry(&tdc->pending_sg_req,
+ typeof(*sgreq), node);
+ sgreq->dma_desc->bytes_transferred +=
+ get_current_xferred_count(tdc, sgreq, status);
+ }
+ tegra_dma_resume(tdc);
+
+skip_dma_stop:
+ tegra_dma_abort_all(tdc);
+ /* Ignore callbacks pending list */
+ INIT_LIST_HEAD(&tdc->cb_desc);
+ spin_unlock_irqrestore(&tdc->lock, flags);
+
+ /* Call callbacks if was pending before aborting requests */
+ while (!list_empty(&cb_dma_desc_list)) {
+ dma_desc = list_first_entry(&cb_dma_desc_list,
+ typeof(*dma_desc), cb_node);
+ list_del(&dma_desc->cb_node);
+ callback = dma_desc->txd.callback;
+ callback_param = dma_desc->txd.callback_param;
+ if (callback)
+ callback(callback_param);
+ }
+}
+
+static enum dma_status tegra_dma_tx_status(struct dma_chan *dc,
+ dma_cookie_t cookie, struct dma_tx_state *txstate)
+{
+ struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
+ struct tegra_dma_desc *dma_desc;
+ struct tegra_dma_sg_req *sg_req;
+ enum dma_status ret;
+ unsigned long flags;
+
+ spin_lock_irqsave(&tdc->lock, flags);
+
+ ret = dma_cookie_status(dc, cookie, txstate);
+ if (ret != DMA_SUCCESS)
+ goto check_pending_q;
+
+ if (list_empty(&tdc->wait_ack_dma_desc))
+ goto check_pending_q;
+
+ /* Check on wait_ack desc status */
+ list_for_each_entry(dma_desc, &tdc->wait_ack_dma_desc, node) {
+ if (dma_desc->cookie == cookie) {
+ dma_set_residue(txstate,
+ dma_desc->bytes_requested -
+ dma_desc->bytes_transferred);
+ ret = dma_desc->dma_status;
+ goto end;
+ }
+ }
+
+check_pending_q:
+ if (list_empty(&tdc->pending_sg_req))
+ goto end;
+
+ /* May be this is in head list of pending list */
+ list_for_each_entry(sg_req, &tdc->pending_sg_req, node) {
+ dma_desc = sg_req->dma_desc;
+ if (dma_desc->txd.cookie == cookie) {
+ dma_set_residue(txstate,
+ dma_desc->bytes_requested -
+ dma_desc->bytes_transferred);
+ ret = dma_desc->dma_status;
+ goto end;
+ }
+ }
+ dev_info(tdc2dev(tdc), "%s(): cookie does not found\n", __func__);
+end:
+ spin_unlock_irqrestore(&tdc->lock, flags);
+ return ret;
+}
+
+static int tegra_dma_device_control(struct dma_chan *dc, enum dma_ctrl_cmd cmd,
+ unsigned long arg)
+{
+ switch (cmd) {
+ case DMA_SLAVE_CONFIG:
+ return tegra_dma_slave_config(dc,
+ (struct dma_slave_config *)arg);
+
+ case DMA_TERMINATE_ALL:
+ tegra_dma_terminate_all(dc);
+ return 0;
+ default:
+ break;
+ }
+
+ return -ENXIO;
+}
+
+static inline int get_bus_width(enum dma_slave_buswidth slave_bw)
+{
+ BUG_ON(!slave_bw);
+ switch (slave_bw) {
+ case DMA_SLAVE_BUSWIDTH_1_BYTE:
+ return APB_SEQ_BUS_WIDTH_8;
+ case DMA_SLAVE_BUSWIDTH_2_BYTES:
+ return APB_SEQ_BUS_WIDTH_16;
+ case DMA_SLAVE_BUSWIDTH_4_BYTES:
+ return APB_SEQ_BUS_WIDTH_32;
+ case DMA_SLAVE_BUSWIDTH_8_BYTES:
+ return APB_SEQ_BUS_WIDTH_64;
+ default:
+ BUG();
+ }
+}
+
+static inline int get_burst_size(struct tegra_dma_channel *tdc,
+ u32 burst_size, enum dma_slave_buswidth slave_bw, int len)
+{
+ int burst_byte;
+ int burst_ahb_width;
+
+ /*
+ * burst_size from client is in terms of the bus_width.
+ * convert them into ahb mmeory width which is 4 byte.
+ */
+ burst_byte = burst_size * slave_bw;
+ burst_ahb_width = burst_byte / 4;
+
+ /* If burst size is 0 then calculate the burst size based on length */
+ if (!burst_ahb_width) {
+ if (len & 0xF)
+ return AHB_SEQ_BURST_1;
+ else if ((len >> 4) & 0x1)
+ return AHB_SEQ_BURST_4;
+ else
+ return AHB_SEQ_BURST_8;
+ }
+ if (burst_ahb_width < 4)
+ return AHB_SEQ_BURST_1;
+ else if (burst_ahb_width < 8)
+ return AHB_SEQ_BURST_4;
+ else
+ return AHB_SEQ_BURST_8;
+}
+
+static bool init_dma_mode(struct tegra_dma_channel *tdc,
+ enum dma_transfer_mode new_mode)
+{
+ if (tdc->dma_mode == DMA_MODE_NONE) {
+ tdc->dma_mode = new_mode;
+ switch (new_mode) {
+ case DMA_MODE_ONCE:
+ tdc->isr_handler = handle_once_dma_done;
+ break;
+ case DMA_MODE_CYCLE:
+ tdc->isr_handler = handle_cont_sngl_cycle_dma_done;
+ break;
+ case DMA_MODE_CYCLE_HALF_NOTIFY:
+ tdc->isr_handler = handle_cont_dbl_cycle_dma_done;
+ break;
+ default:
+ break;
+ }
+ } else {
+ if (new_mode != tdc->dma_mode)
+ return false;
+ }
+ return true;
+}
+
+static struct dma_async_tx_descriptor *tegra_dma_prep_slave_sg(
+ struct dma_chan *dc, struct scatterlist *sgl, unsigned int sg_len,
+ enum dma_transfer_direction direction, unsigned long flags,
+ void *context)
+{
+ struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
+ struct tegra_dma_desc *dma_desc;
+ unsigned int i;
+ struct scatterlist *sg;
+ unsigned long csr, ahb_seq, apb_ptr, apb_seq;
+ struct list_head req_list;
+ struct tegra_dma_sg_req *sg_req = NULL;
+ u32 burst_size;
+ enum dma_slave_buswidth slave_bw;
+
+ if (!tdc->config_init) {
+ dev_err(tdc2dev(tdc), "dma channel is not configured\n");
+ return NULL;
+ }
+ if (sg_len < 1) {
+ dev_err(tdc2dev(tdc), "Invalid segment length %d\n", sg_len);
+ return NULL;
+ }
+
+ INIT_LIST_HEAD(&req_list);
+
+ ahb_seq = AHB_SEQ_INTR_ENB;
+ ahb_seq |= AHB_SEQ_WRAP_NONE << AHB_SEQ_WRAP_SHIFT;
+ ahb_seq |= AHB_SEQ_BUS_WIDTH_32;
+
+ csr = CSR_ONCE | CSR_FLOW;
+ csr |= tdc->dma_sconfig.slave_id << CSR_REQ_SEL_SHIFT;
+ if (flags & DMA_PREP_INTERRUPT)
+ csr |= CSR_IE_EOC;
+
+ apb_seq = APB_SEQ_WRAP_WORD_1;
+
+ switch (direction) {
+ case DMA_MEM_TO_DEV:
+ apb_ptr = tdc->dma_sconfig.dst_addr;
+ apb_seq |= get_bus_width(tdc->dma_sconfig.dst_addr_width);
+ burst_size = tdc->dma_sconfig.dst_maxburst;
+ slave_bw = tdc->dma_sconfig.dst_addr_width;
+ csr |= CSR_DIR;
+ break;
+
+ case DMA_DEV_TO_MEM:
+ apb_ptr = tdc->dma_sconfig.src_addr;
+ apb_seq |= get_bus_width(tdc->dma_sconfig.src_addr_width);
+ burst_size = tdc->dma_sconfig.src_maxburst;
+ slave_bw = tdc->dma_sconfig.src_addr_width;
+ break;
+ default:
+ dev_err(tdc2dev(tdc), "Dma direction is not supported\n");
+ return NULL;
+ }
+
+ dma_desc = tegra_dma_desc_get(tdc);
+ if (!dma_desc) {
+ dev_err(tdc2dev(tdc), "Dma descriptors not available\n");
+ goto fail;
+ }
+ INIT_LIST_HEAD(&dma_desc->tx_list);
+ INIT_LIST_HEAD(&dma_desc->cb_node);
+ dma_desc->bytes_requested = 0;
+ dma_desc->bytes_transferred = 0;
+ dma_desc->dma_status = DMA_IN_PROGRESS;
+
+ /* Make transfer requests */
+ for_each_sg(sgl, sg, sg_len, i) {
+ u32 len, mem;
+
+ mem = sg_phys(sg);
+ len = sg_dma_len(sg);
+
+ if ((len & 3) || (mem & 3) ||
+ (len > tdc->tdma->chip_data.max_dma_count)) {
+ dev_err(tdc2dev(tdc),
+ "Dma length/memory address is not supported\n");
+ goto fail;
+ }
+
+ sg_req = tegra_dma_sg_req_get(tdc);
+ if (!sg_req) {
+ dev_err(tdc2dev(tdc), "Dma sg-req not available\n");
+ goto fail;
+ }
+
+ ahb_seq |= get_burst_size(tdc, burst_size, slave_bw, len);
+ dma_desc->bytes_requested += len;
+
+ sg_req->ch_regs.apb_ptr = apb_ptr;
+ sg_req->ch_regs.ahb_ptr = mem;
+ sg_req->ch_regs.csr = csr | ((len - 4) & 0xFFFC);
+ sg_req->ch_regs.apb_seq = apb_seq;
+ sg_req->ch_regs.ahb_seq = ahb_seq;
+ sg_req->configured = false;
+ sg_req->last_sg = false;
+ sg_req->dma_desc = dma_desc;
+ sg_req->req_len = len;
+
+ list_add_tail(&sg_req->node, &dma_desc->tx_list);
+ }
+ sg_req->last_sg = true;
+ dma_desc->ack_reqd = (flags & DMA_CTRL_ACK) ? false : true;
+ if (dma_desc->ack_reqd)
+ dma_desc->txd.flags = DMA_CTRL_ACK;
+
+ /*
+ * Make sure that mode should not be conflicting with currently
+ * configured mode.
+ */
+ if (!init_dma_mode(tdc, DMA_MODE_ONCE)) {
+ dev_err(tdc2dev(tdc), "Conflict in dma modes\n");
+ goto fail;
+ }
+
+ return &dma_desc->txd;
+
+fail:
+ tegra_dma_desc_put(tdc, dma_desc);
+ return NULL;
+}
+
+struct dma_async_tx_descriptor *tegra_dma_prep_dma_cyclic(
+ struct dma_chan *dc, dma_addr_t buf_addr, size_t buf_len,
+ size_t period_len, enum dma_transfer_direction direction,
+ void *context)
+{
+ struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
+ struct tegra_dma_desc *dma_desc = NULL;
+ struct tegra_dma_sg_req *sg_req = NULL;
+ unsigned long csr, ahb_seq, apb_ptr, apb_seq;
+ int len;
+ bool half_buffer_notify;
+ enum dma_transfer_mode new_mode;
+ size_t remain_len;
+ dma_addr_t mem = buf_addr;
+ u32 burst_size;
+ enum dma_slave_buswidth slave_bw;
+
+ if (!buf_len) {
+ dev_err(tdc2dev(tdc),
+ "Buffer length is invalid len %d\n", buf_len);
+ }
+
+ if (!tdc->config_init) {
+ dev_err(tdc2dev(tdc),
+ "DMA is not configured for slave\n");
+ return NULL;
+ }
+
+ if (tdc->busy) {
+ dev_err(tdc2dev(tdc),
+ "DMA is already started, can not accept any more requests\n");
+ return NULL;
+ }
+
+ /*
+ * We only support cycle transfer when buf_len is multiple of
+ * period_len.
+ * With period of buf_len, it will set dma mode DMA_MODE_CYCLE
+ * with one request.
+ * With period of buf_len/2, it will set dma mode
+ * DMA_MODE_CYCLE_HALF_NOTIFY with one requsts.
+ * Othercase, the transfer is broken in smaller requests of size
+ * of period_len and the transfer continues forever in cyclic way
+ * dma mode of DMA_MODE_CYCLE.
+ * If period_len is zero then assume dma mode DMA_MODE_CYCLE.
+ * We also allow to take more number of requests till dma is
+ * not started. The driver will loop over all requests.
+ * Once dma is started then new requests can be queued only after
+ * terminating the dma.
+ */
+ if (!period_len)
+ period_len = buf_len;
+
+ if (buf_len % period_len) {
+ dev_err(tdc2dev(tdc),
+ "buf_len %d should be multiple of period_len %d\n",
+ buf_len, period_len);
+ return NULL;
+ }
+
+ half_buffer_notify = (buf_len == (2 * period_len)) ? true : false;
+ len = (half_buffer_notify) ? buf_len / 2 : period_len;
+ if ((len & 3) || (buf_addr & 3) ||
+ (len > tdc->tdma->chip_data.max_dma_count)) {
+ dev_err(tdc2dev(tdc),
+ "Dma length/memory address is not correct\n");
+ return NULL;
+ }
+
+ ahb_seq = AHB_SEQ_INTR_ENB;
+ ahb_seq |= AHB_SEQ_WRAP_NONE << AHB_SEQ_WRAP_SHIFT;
+ ahb_seq |= AHB_SEQ_BUS_WIDTH_32;
+ if (half_buffer_notify)
+ ahb_seq |= AHB_SEQ_DBL_BUF;
+
+ csr = CSR_FLOW | CSR_IE_EOC;
+ csr |= tdc->dma_sconfig.slave_id << CSR_REQ_SEL_SHIFT;
+
+ apb_seq = APB_SEQ_WRAP_WORD_1;
+
+ switch (direction) {
+ case DMA_MEM_TO_DEV:
+ apb_ptr = tdc->dma_sconfig.dst_addr;
+ apb_seq |= get_bus_width(tdc->dma_sconfig.dst_addr_width);
+ burst_size = tdc->dma_sconfig.dst_maxburst;
+ slave_bw = tdc->dma_sconfig.dst_addr_width;
+ csr |= CSR_DIR;
+ break;
+
+ case DMA_DEV_TO_MEM:
+ apb_ptr = tdc->dma_sconfig.src_addr;
+ apb_seq |= get_bus_width(tdc->dma_sconfig.src_addr_width);
+ burst_size = tdc->dma_sconfig.src_maxburst;
+ slave_bw = tdc->dma_sconfig.src_addr_width;
+ break;
+ default:
+ dev_err(tdc2dev(tdc), "Dma direction is not supported\n");
+ return NULL;
+ }
+
+ dma_desc = tegra_dma_desc_get(tdc);
+ if (!dma_desc) {
+ dev_err(tdc2dev(tdc), "not enough descriptors available\n");
+ goto fail;
+ }
+ INIT_LIST_HEAD(&dma_desc->tx_list);
+
+ dma_desc->bytes_transferred = 0;
+ dma_desc->bytes_requested = buf_len;
+ remain_len = (half_buffer_notify) ? len : buf_len;
+
+ while (remain_len) {
+ sg_req = tegra_dma_sg_req_get(tdc);
+ if (!sg_req) {
+ dev_err(tdc2dev(tdc), "Dma sg-req not available\n");
+ goto fail;
+ }
+
+ ahb_seq |= get_burst_size(tdc, burst_size, slave_bw, len);
+ sg_req->ch_regs.apb_ptr = apb_ptr;
+ sg_req->ch_regs.ahb_ptr = mem;
+ sg_req->ch_regs.csr = csr | ((len - 4) & 0xFFFC);
+ sg_req->ch_regs.apb_seq = apb_seq;
+ sg_req->ch_regs.ahb_seq = ahb_seq;
+ sg_req->configured = false;
+ sg_req->half_done = false;
+ sg_req->last_sg = false;
+ sg_req->dma_desc = dma_desc;
+ sg_req->req_len = len;
+
+ list_add_tail(&sg_req->node, &dma_desc->tx_list);
+ remain_len -= len;
+ mem += len;
+ }
+ sg_req->last_sg = true;
+ dma_desc->ack_reqd = true;
+ dma_desc->txd.flags = DMA_CTRL_ACK;
+
+ /*
+ * We can not change the dma mode once it is initialized
+ * until all desc are terminated.
+ */
+ new_mode = (half_buffer_notify) ?
+ DMA_MODE_CYCLE_HALF_NOTIFY : DMA_MODE_CYCLE;
+ if (!init_dma_mode(tdc, new_mode)) {
+ dev_err(tdc2dev(tdc), "Conflict in dma modes\n");
+ goto fail;
+ }
+
+ return &dma_desc->txd;
+
+fail:
+ tegra_dma_desc_put(tdc, dma_desc);
+ return NULL;
+}
+
+static int tegra_dma_alloc_chan_resources(struct dma_chan *dc)
+{
+ struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
+ int total_desc;
+
+ total_desc = allocate_tegra_desc(tdc, DMA_NR_DESCS_PER_CHANNEL,
+ DMA_NR_DESCS_PER_CHANNEL * DMA_NR_REQ_PER_DESC);
+ dma_cookie_init(&tdc->dma_chan);
+ dev_dbg(tdc2dev(tdc),
+ "%s(): allocated %d descriptors\n", __func__, total_desc);
+ tdc->config_init = false;
+ return total_desc;
+}
+
+static void tegra_dma_free_chan_resources(struct dma_chan *dc)
+{
+ struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
+
+ struct tegra_dma_desc *dma_desc;
+ struct tegra_dma_sg_req *sg_req;
+ struct list_head dma_desc_list;
+ struct list_head sg_req_list;
+ unsigned long flags;
+
+ INIT_LIST_HEAD(&dma_desc_list);
+ INIT_LIST_HEAD(&sg_req_list);
+
+ dev_dbg(tdc2dev(tdc),
+ "%s(): channel %d and desc freeing %d\n",
+ __func__, tdc->id, tdc->descs_allocated);
+
+ if (tdc->busy)
+ tegra_dma_terminate_all(dc);
+
+ spin_lock_irqsave(&tdc->lock, flags);
+ list_splice_init(&tdc->pending_sg_req, &sg_req_list);
+ list_splice_init(&tdc->free_sg_req, &sg_req_list);
+ list_splice_init(&tdc->free_dma_desc, &dma_desc_list);
+ list_splice_init(&tdc->wait_ack_dma_desc, &dma_desc_list);
+ INIT_LIST_HEAD(&tdc->cb_desc);
+ tdc->descs_allocated = 0;
+ tdc->config_init = false;
+ spin_unlock_irqrestore(&tdc->lock, flags);
+
+ while (!list_empty(&dma_desc_list)) {
+ dma_desc = list_first_entry(&dma_desc_list,
+ typeof(*dma_desc), node);
+ list_del(&dma_desc->node);
+ }
+
+ while (!list_empty(&sg_req_list)) {
+ sg_req = list_first_entry(&sg_req_list, typeof(*sg_req), node);
+ list_del(&sg_req->node);
+ }
+}
+
+/* Tegra20 specific dma controller information */
+static struct tegra_dma_chip_data tegra20_chip_data = {
+ .nr_channels = 16,
+ .max_dma_count = 1024UL * 64,
+};
+
+/* Tegra30 specific dma controller information */
+static struct tegra_dma_chip_data tegra30_chip_data = {
+ .nr_channels = 32,
+ .max_dma_count = 1024UL * 64,
+};
+
+#if defined(CONFIG_OF)
+/* Match table for of_platform binding */
+static const struct of_device_id tegra_dma_of_match[] __devinitconst = {
+ { .compatible = "nvidia,tegra30-apbdma", .data = &tegra30_chip_data, },
+ { .compatible = "nvidia,tegra20-apbdma", .data = &tegra20_chip_data, },
+ {},
+};
+MODULE_DEVICE_TABLE(of, tegra_dma_of_match);
+#else
+#define tegra_dma_of_match NULL
+#endif
+
+static struct platform_device_id dma_id_table[] = {
+ {.name = "tegra30-apbdma", .driver_data = (ulong)&tegra30_chip_data, },
+ {.name = "tegra20-apbdma", .driver_data = (ulong)&tegra20_chip_data, },
+ {},
+};
+
+static bool tdma_volatile_reg(struct device *dev, unsigned int reg)
+{
+ unsigned int chan_reg;
+
+ if (reg < DMA_CHANNEL_BASE_ADDRESS_OFFSET)
+ return false;
+
+ chan_reg = (reg - DMA_CHANNEL_BASE_ADDRESS_OFFSET) %
+ DMA_CHANNEL_REGISTER_SIZE;
+ switch (chan_reg) {
+ case APB_DMA_CHAN_STA:
+ case APB_DMA_CHAN_CSR:
+ return true;
+ }
+ return false;
+}
+
+static bool tdma_wr_rd_reg(struct device *dev, unsigned int reg)
+{
+ unsigned int chan_reg;
+
+ /* Dma base registers */
+ if (reg < DMA_CHANNEL_BASE_ADDRESS_OFFSET) {
+ switch (reg) {
+ case APB_DMA_GEN:
+ case APB_DMA_CNTRL:
+ case APB_DMA_IRQ_MASK:
+ case APB_DMA_IRQ_MASK_SET:
+ return true;
+ default:
+ return false;
+ }
+ }
+
+ /* Channel registers */
+ chan_reg = (reg - DMA_CHANNEL_BASE_ADDRESS_OFFSET) %
+ DMA_CHANNEL_REGISTER_SIZE;
+ switch (chan_reg) {
+ case APB_DMA_CHAN_CSR:
+ case APB_DMA_CHAN_STA:
+ case APB_DMA_CHAN_APB_SEQ:
+ case APB_DMA_CHAN_APB_PTR:
+ case APB_DMA_CHAN_AHB_SEQ:
+ case APB_DMA_CHAN_AHB_PTR:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static struct regmap_config tdma_regmap_config = {
+ .name = "tegra-apbdma",
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = 4,
+ .volatile_reg = tdma_volatile_reg,
+ .writeable_reg = tdma_wr_rd_reg,
+ .readable_reg = tdma_wr_rd_reg,
+ .cache_type = REGCACHE_RBTREE,
+};
+
+static int __devinit tegra_dma_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct tegra_dma *tdma;
+ size_t size;
+ int ret;
+ int i;
+ struct tegra_dma_chip_data *chip_data = NULL;
+
+#if defined(CONFIG_OF)
+ {
+ const struct of_device_id *match;
+ match = of_match_device(of_match_ptr(tegra_dma_of_match),
+ &pdev->dev);
+ if (match)
+ chip_data = match->data;
+ }
+#else
+ chip_data = (struct tegra_dma_chip_data *)pdev->id_entry->driver_data;
+#endif
+ if (!chip_data) {
+ dev_err(&pdev->dev, "Error: Chip data is not valid\n");
+ return -EINVAL;
+ }
+
+ size = sizeof(struct tegra_dma);
+ size += chip_data->nr_channels * sizeof(struct tegra_dma_channel);
+ tdma = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
+ if (!tdma) {
+ dev_err(&pdev->dev, "Error: memory allocation failed\n");
+ return -ENOMEM;
+ }
+
+ tdma->dev = &pdev->dev;
+ memcpy(&tdma->chip_data, chip_data, sizeof(*chip_data));
+ platform_set_drvdata(pdev, tdma);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "no mem resource for DMA\n");
+ return -EINVAL;
+ }
+
+ tdma->base_addr = devm_request_and_ioremap(&pdev->dev, res);
+ if (!tdma->base_addr) {
+ dev_err(&pdev->dev,
+ "Cannot request memregion/iomap dma address\n");
+ return -EADDRNOTAVAIL;
+ }
+
+ /* Dma base register */
+ tdma_regmap_config.max_register = resource_size(res);
+ tdma->regmap_dma = devm_regmap_init_mmio(&pdev->dev, tdma->base_addr,
+ (const struct regmap_config *)&tdma_regmap_config);
+ if (IS_ERR(tdma->regmap_dma)) {
+ dev_err(&pdev->dev, "regmap init failed\n");
+ return PTR_ERR(tdma->regmap_dma);
+ }
+
+ /* Clock */
+ tdma->dma_clk = clk_get(&pdev->dev, "clk");
+ if (IS_ERR(tdma->dma_clk)) {
+ dev_err(&pdev->dev, "Error: Missing controller clock");
+ return PTR_ERR(tdma->dma_clk);
+ }
+
+ spin_lock_init(&tdma->global_lock);
+
+ INIT_LIST_HEAD(&tdma->dma_dev.channels);
+ for (i = 0; i < chip_data->nr_channels; i++) {
+ struct tegra_dma_channel *tdc = &tdma->channels[i];
+ char irq_name[30];
+
+ tdc->chan_base_offset = DMA_CHANNEL_BASE_ADDRESS_OFFSET +
+ i * DMA_CHANNEL_REGISTER_SIZE;
+
+ res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
+ if (!res) {
+ ret = -EINVAL;
+ dev_err(&pdev->dev,
+ "Irq resource not found for channel %d\n", i);
+ goto err_irq;
+ }
+ tdc->irq = res->start;
+ snprintf(irq_name, sizeof(irq_name), "tegra_dma_chan.%d", i);
+ ret = devm_request_irq(&pdev->dev, tdc->irq,
+ tegra_dma_isr, 0, irq_name, tdc);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "request_irq failed for channel %d error %d\n",
+ i, ret);
+ goto err_irq;
+ }
+
+ tdc->dma_chan.device = &tdma->dma_dev;
+ dma_cookie_init(&tdc->dma_chan);
+ list_add_tail(&tdc->dma_chan.device_node,
+ &tdma->dma_dev.channels);
+ tdc->tdma = tdma;
+ tdc->id = i;
+
+ tasklet_init(&tdc->tasklet,
+ tegra_dma_tasklet, (unsigned long)tdc);
+ spin_lock_init(&tdc->lock);
+
+ INIT_LIST_HEAD(&tdc->pending_sg_req);
+ INIT_LIST_HEAD(&tdc->free_sg_req);
+ INIT_LIST_HEAD(&tdc->free_dma_desc);
+ INIT_LIST_HEAD(&tdc->wait_ack_dma_desc);
+ INIT_LIST_HEAD(&tdc->cb_desc);
+ }
+
+ dma_cap_set(DMA_SLAVE, tdma->dma_dev.cap_mask);
+ dma_cap_set(DMA_PRIVATE, tdma->dma_dev.cap_mask);
+ tdma->dma_dev.dev = &pdev->dev;
+ tdma->dma_dev.device_alloc_chan_resources =
+ tegra_dma_alloc_chan_resources;
+ tdma->dma_dev.device_free_chan_resources =
+ tegra_dma_free_chan_resources;
+ tdma->dma_dev.device_prep_slave_sg = tegra_dma_prep_slave_sg;
+ tdma->dma_dev.device_prep_dma_cyclic = tegra_dma_prep_dma_cyclic;
+ tdma->dma_dev.device_control = tegra_dma_device_control;
+ tdma->dma_dev.device_tx_status = tegra_dma_tx_status;
+ tdma->dma_dev.device_issue_pending = tegra_dma_issue_pending;
+
+ ret = dma_async_device_register(&tdma->dma_dev);
+ if (ret < 0) {
+ dev_err(&pdev->dev,
+ "Error in registering Tegra APB DMA driver %d\n", ret);
+ goto err_irq;
+ }
+ dev_info(&pdev->dev, "Tegra APB DMA Controller, %d channels\n",
+ chip_data->nr_channels);
+ pm_runtime_enable(&pdev->dev);
+ pm_runtime_get_sync(&pdev->dev);
+
+ /* Reset dma controller */
+ tegra_periph_reset_assert(tdma->dma_clk);
+ tegra_periph_reset_deassert(tdma->dma_clk);
+
+ /* Enable global dma registers */
+ tdma_write(tdma, APB_DMA_GEN, GEN_ENABLE);
+ tdma_write(tdma, APB_DMA_CNTRL, 0);
+ tdma_write(tdma, APB_DMA_IRQ_MASK_SET, 0xFFFFFFFFul);
+ return 0;
+
+err_irq:
+ while (--i >= 0) {
+ struct tegra_dma_channel *tdc = &tdma->channels[i];
+ tasklet_kill(&tdc->tasklet);
+ }
+
+ pm_runtime_disable(&pdev->dev);
+ clk_put(tdma->dma_clk);
+ return ret;
+}
+
+static int __exit tegra_dma_remove(struct platform_device *pdev)
+{
+ struct tegra_dma *tdma = platform_get_drvdata(pdev);
+ int i;
+ struct tegra_dma_channel *tdc;
+
+ dma_async_device_unregister(&tdma->dma_dev);
+
+ for (i = 0; i < tdma->chip_data.nr_channels; ++i) {
+ tdc = &tdma->channels[i];
+ tasklet_kill(&tdc->tasklet);
+ }
+
+ pm_runtime_disable(&pdev->dev);
+ clk_put(tdma->dma_clk);
+
+ return 0;
+}
+
+static int tegra_dma_runtime_idle(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct tegra_dma *tdma = platform_get_drvdata(pdev);
+
+ regcache_cache_only(tdma->regmap_dma, true);
+ clk_disable(tdma->dma_clk);
+ return 0;
+}
+
+static int tegra_dma_runtime_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct tegra_dma *tdma = platform_get_drvdata(pdev);
+ clk_enable(tdma->dma_clk);
+ regcache_cache_only(tdma->regmap_dma, false);
+ return 0;
+}
+
+static int tegra_dma_suspend_noirq(struct device *dev)
+{
+ tegra_dma_runtime_idle(dev);
+ return 0;
+}
+
+static int tegra_dma_resume_noirq(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct tegra_dma *tdma = platform_get_drvdata(pdev);
+
+ tegra_dma_runtime_resume(dev);
+
+ /*
+ * After resume, dma register will not be sync with the cached value.
+ * Making sure they are in sync.
+ */
+ regcache_mark_dirty(tdma->regmap_dma);
+ regcache_sync(tdma->regmap_dma);
+ return 0;
+}
+
+static const struct dev_pm_ops tegra_dma_dev_pm_ops = {
+ .suspend_noirq = tegra_dma_suspend_noirq,
+ .resume_noirq = tegra_dma_resume_noirq,
+ .runtime_idle = tegra_dma_runtime_idle,
+ .runtime_resume = tegra_dma_runtime_resume,
+};
+
+static struct platform_driver tegra_dmac_driver = {
+ .driver = {
+ .name = "tegra-apbdma",
+ .owner = THIS_MODULE,
+ .pm = &tegra_dma_dev_pm_ops,
+ .of_match_table = tegra_dma_of_match,
+ },
+ .probe = tegra_dma_probe,
+ .remove = __exit_p(tegra_dma_remove),
+ .id_table = dma_id_table,
+};
+
+static int __init tegra_dmac_init(void)
+{
+ return platform_driver_register(&tegra_dmac_driver);
+}
+arch_initcall_sync(tegra_dmac_init);
+
+static void __exit tegra_dmac_exit(void)
+{
+ platform_driver_unregister(&tegra_dmac_driver);
+}
+module_exit(tegra_dmac_exit);
+
+MODULE_DESCRIPTION("NVIDIA Tegra DMA Controller driver");
+MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:tegra-apbdma");
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 1082698..b0b275f 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -338,6 +338,9 @@ enum dma_slave_buswidth {
* @device_fc: Flow Controller Settings. Only valid for slave channels. Fill
* with 'true' if peripheral should be flow controller. Direction will be
* selected at Runtime.
+ * @slave_id: Slave requester id. Only valid for slave channels. The dma
+ * slave peripheral will have unique id as dma requester which need to be
+ * pass as slave config.
*
* This struct is passed in as configuration data to a DMA engine
* in order to set up a certain channel for DMA transport at runtime.
@@ -365,6 +368,7 @@ struct dma_slave_config {
u32 src_maxburst;
u32 dst_maxburst;
bool device_fc;
+ int slave_id;
};
static inline const char *dma_chan_name(struct dma_chan *chan)
--
1.7.1.1
^ permalink raw reply related [flat|nested] 16+ messages in thread