Adding GPC DMA controller driver for Tegra186 and Tegra194. The driver
supports dma transfers between memory to memory, IO peripheral to memory
and memory to IO peripheral.

Signed-off-by: Pavan Kunapuli <pkunap...@nvidia.com>
Signed-off-by: Rajesh Gumasta <rguma...@nvidia.com>
---
 drivers/dma/Kconfig         |   12 +
 drivers/dma/Makefile        |    1 +
 drivers/dma/tegra-gpc-dma.c | 1472 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 1485 insertions(+)
 create mode 100644 drivers/dma/tegra-gpc-dma.c

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index e9ed916..84b3a0a 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -639,6 +639,18 @@ config TEGRA210_ADMA
          peripheral and vice versa. It does not support memory to
          memory data transfer.
 
+config TEGRA_GPC_DMA
+       tristate "NVIDIA Tegra GPC DMA support"
+       depends on ARCH_TEGRA_186_SOC || ARCH_TEGRA_194_SOC || COMPILE_TEST
+       select DMA_ENGINE
+       help
+         Support for the NVIDIA Tegra186 and Tegra194 GPC DMA controller
+         driver. The DMA controller has multiple DMA channels which can
+         be configured for different peripherals like UART, SPI, etc
+         which are on APB bus.
+         This DMA controller transfers data from memory to peripheral FIFO
+         or vice versa. It also supports memory to memory data transfer.
+
 config TIMB_DMA
        tristate "Timberdale FPGA DMA support"
        depends on MFD_TIMBERDALE || COMPILE_TEST
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index e60f813..43e3a6e 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -76,6 +76,7 @@ obj-$(CONFIG_S3C24XX_DMAC) += s3c24xx-dma.o
 obj-$(CONFIG_TXX9_DMAC) += txx9dmac.o
 obj-$(CONFIG_TEGRA20_APB_DMA) += tegra20-apb-dma.o
 obj-$(CONFIG_TEGRA210_ADMA) += tegra210-adma.o
+obj-$(CONFIG_TEGRA_GPC_DMA) += tegra-gpc-dma.o
 obj-$(CONFIG_TIMB_DMA) += timb_dma.o
 obj-$(CONFIG_UNIPHIER_MDMAC) += uniphier-mdmac.o
 obj-$(CONFIG_UNIPHIER_XDMAC) += uniphier-xdmac.o
diff --git a/drivers/dma/tegra-gpc-dma.c b/drivers/dma/tegra-gpc-dma.c
new file mode 100644
index 0000000..723b352
--- /dev/null
+++ b/drivers/dma/tegra-gpc-dma.c
@@ -0,0 +1,1472 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * DMA driver for Nvidia's Tegra186 and Tegra194 GPC DMA controller.
+ *
+ * Copyright (c) 2014-2020, NVIDIA CORPORATION.  All rights reserved.
+ */
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_dma.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+#include <linux/version.h>
+#include <dt-bindings/memory/tegra186-mc.h>
+#include "virt-dma.h"
+
+/* CSR register */
+#define TEGRA_GPCDMA_CHAN_CSR                  0x00
+#define TEGRA_GPCDMA_CSR_ENB                   BIT(31)
+#define TEGRA_GPCDMA_CSR_IE_EOC                        BIT(30)
+#define TEGRA_GPCDMA_CSR_ONCE                  BIT(27)
+#define TEGRA_GPCDMA_CSR_FC_MODE_NO_MMIO       (0 << 24)
+#define TEGRA_GPCDMA_CSR_FC_MODE_ONE_MMIO      BIT(24)
+#define TEGRA_GPCDMA_CSR_FC_MODE_TWO_MMIO      BIT(25)
+#define TEGRA_GPCDMA_CSR_FC_MODE_FOUR_MMIO     GENMASK(25, 24)
+#define TEGRA_GPCDMA_CSR_DMA_IO2MEM_NO_FC      (0 << 21)
+#define TEGRA_GPCDMA_CSR_DMA_IO2MEM_FC         BIT(21)
+#define TEGRA_GPCDMA_CSR_DMA_MEM2IO_NO_FC      BIT(22)
+#define TEGRA_GPCDMA_CSR_DMA_MEM2IO_FC         GENMASK(22, 21)
+#define TEGRA_GPCDMA_CSR_DMA_MEM2MEM           BIT(23)
+#define TEGRA_GPCDMA_CSR_DMA_FIXED_PAT         GENMASK(23, 22)
+#define TEGRA_GPCDMA_CSR_REQ_SEL_SHIFT         16
+#define TEGRA_GPCDMA_CSR_REQ_SEL_MASK          GENMASK(20, 16)
+#define TEGRA_GPCDMA_CSR_REQ_SEL_UNUSED        BIT(18)
+#define TEGRA_GPCDMA_CSR_IRQ_MASK              BIT(15)
+#define TEGRA_GPCDMA_CSR_WEIGHT_SHIFT          10
+
+/* STATUS register */
+#define TEGRA_GPCDMA_CHAN_STATUS               0x004
+#define TEGRA_GPCDMA_STATUS_BUSY               BIT(31)
+#define TEGRA_GPCDMA_STATUS_ISE_EOC            BIT(30)
+#define TEGRA_GPCDMA_STATUS_PING_PONG          BIT(28)
+#define TEGRA_GPCDMA_STATUS_DMA_ACTIVITY       BIT(27)
+#define TEGRA_GPCDMA_STATUS_CHANNEL_PAUSE      BIT(26)
+#define TEGRA_GPCDMA_STATUS_CHANNEL_RX         BIT(25)
+#define TEGRA_GPCDMA_STATUS_CHANNEL_TX         BIT(24)
+#define TEGRA_GPCDMA_STATUS_IRQ_INTR_STA       BIT(23)
+#define TEGRA_GPCDMA_STATUS_IRQ_STA            BIT(21)
+#define TEGRA_GPCDMA_STATUS_IRQ_TRIG_STA       BIT(20)
+
+#define TEGRA_GPCDMA_CHAN_CSRE                 0x008
+#define TEGRA_GPCDMA_CHAN_CSRE_PAUSE           BIT(31)
+
+/* Source address */
+#define TEGRA_GPCDMA_CHAN_SRC_PTR              0x00C
+
+/* Destination address */
+#define TEGRA_GPCDMA_CHAN_DST_PTR              0x010
+
+/* High address pointer */
+#define TEGRA_GPCDMA_CHAN_HIGH_ADDR_PTR        0x014
+#define TEGRA_GPCDMA_HIGH_ADDR_SCR_PTR_SHIFT   0
+#define TEGRA_GPCDMA_HIGH_ADDR_SCR_PTR_MASK    0xFF
+#define TEGRA_GPCDMA_HIGH_ADDR_DST_PTR_SHIFT   16
+#define TEGRA_GPCDMA_HIGH_ADDR_DST_PTR_MASK    0xFF
+
+/* MC sequence register */
+#define TEGRA_GPCDMA_CHAN_MCSEQ                        0x18
+#define TEGRA_GPCDMA_MCSEQ_DATA_SWAP           BIT(31)
+#define TEGRA_GPCDMA_MCSEQ_REQ_COUNT_SHIFT     25
+#define TEGRA_GPCDMA_MCSEQ_BURST_2             (0 << 23)
+#define TEGRA_GPCDMA_MCSEQ_BURST_16            GENMASK(24, 23)
+#define TEGRA_GPCDMA_MCSEQ_WRAP1_SHIFT         20
+#define TEGRA_GPCDMA_MCSEQ_WRAP0_SHIFT         17
+#define TEGRA_GPCDMA_MCSEQ_WRAP_NONE           0
+#define TEGRA_GPCDMA_MCSEQ_MC_PROT_SHIFT       14
+#define TEGRA_GPCDMA_MCSEQ_STREAM_ID1_SHIFT    7
+#define TEGRA_GPCDMA_MCSEQ_STREAM_ID0_SHIFT    0
+#define TEGRA_GPCDMA_MCSEQ_STREAM_ID_MASK      0x7F
+
+/* MMIO sequence register */
+#define TEGRA_GPCDMA_CHAN_MMIOSEQ              0x01c
+#define TEGRA_GPCDMA_MMIOSEQ_DBL_BUF           BIT(31)
+#define TEGRA_GPCDMA_MMIOSEQ_BUS_WIDTH_8       (0 << 28)
+#define TEGRA_GPCDMA_MMIOSEQ_BUS_WIDTH_16      BIT(28)
+#define TEGRA_GPCDMA_MMIOSEQ_BUS_WIDTH_32      BIT(29)
+#define TEGRA_GPCDMA_MMIOSEQ_BUS_WIDTH_64      GENMASK(29, 28)
+#define TEGRA_GPCDMA_MMIOSEQ_BUS_WIDTH_128     BIT(30)
+#define TEGRA_GPCDMA_MMIOSEQ_DATA_SWAP         BIT(27)
+#define TEGRA_GPCDMA_MMIOSEQ_BURST_1           (0 << 23)
+#define TEGRA_GPCDMA_MMIOSEQ_BURST_2           BIT(23)
+#define TEGRA_GPCDMA_MMIOSEQ_BURST_4           GENMASK(24, 23)
+#define TEGRA_GPCDMA_MMIOSEQ_BURST_8           GENMASK(25, 23)
+#define TEGRA_GPCDMA_MMIOSEQ_BURST_16          GENMASK(26, 23)
+#define TEGRA_GPCDMA_MMIOSEQ_MASTER_ID_SHIFT   19
+#define TEGRA_GPCDMA_MMIOSEQ_WRAP_WORD_SHIFT   16
+#define TEGRA_GPCDMA_MMIOSEQ_MMIO_PROT_SHIFT   7
+
+/* Channel WCOUNT */
+#define TEGRA_GPCDMA_CHAN_WCOUNT               0x20
+
+/* Transfer count */
+#define TEGRA_GPCDMA_CHAN_XFER_COUNT           0x24
+
+/* DMA byte count status */
+#define TEGRA_GPCDMA_CHAN_DMA_BYTE_STATUS      0x28
+
+/* Error Status Register */
+#define TEGRA_GPCDMA_CHAN_ERR_STATUS           0x30
+#define TEGRA_GPCDMA_CHAN_ERR_TYPE_SHIFT       (8)
+#define TEGRA_GPCDMA_CHAN_ERR_TYPE_MASK        (0xF)
+#define TEGRA_GPCDMA_CHAN_ERR_TYPE(err)        (                       \
+               ((err) >> TEGRA_GPCDMA_CHAN_ERR_TYPE_SHIFT) &   \
+               TEGRA_GPCDMA_CHAN_ERR_TYPE_MASK)
+#define TEGRA_DMA_BM_FIFO_FULL_ERR             (0xF)
+#define TEGRA_DMA_PERIPH_FIFO_FULL_ERR         (0xE)
+#define TEGRA_DMA_PERIPH_ID_ERR                        (0xD)
+#define TEGRA_DMA_STREAM_ID_ERR                        (0xC)
+#define TEGRA_DMA_MC_SLAVE_ERR                 (0xB)
+#define TEGRA_DMA_MMIO_SLAVE_ERR               (0xA)
+
+/* Fixed Pattern */
+#define TEGRA_GPCDMA_CHAN_FIXED_PATTERN                0x34
+
+#define TEGRA_GPCDMA_CHAN_TZ                   0x38
+#define TEGRA_GPCDMA_CHAN_TZ_MMIO_PROT_1       BIT(0)
+#define TEGRA_GPCDMA_CHAN_TZ_MC_PROT_1         BIT(1)
+
+#define TEGRA_GPCDMA_CHAN_SPARE                        0x3c
+#define TEGRA_GPCDMA_CHAN_SPARE_EN_LEGACY_FC   BIT(16)
+
+/*
+ * 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 TEGRA_GPCDMA_BURST_COMPLETE_TIME       20
+#define TEGRA_GPCDMA_BURST_COMPLETION_TIMEOUT  100
+
+/* Channel base address offset from GPCDMA base address */
+#define TEGRA_GPCDMA_CHANNEL_BASE_ADD_OFFSET   0x10000
+
+struct tegra_dma;
+
+/*
+ * tegra_dma_chip_data Tegra chip specific DMA data
+ * @nr_channels: Number of channels available in the controller.
+ * @channel_reg_size: Channel register size.
+ * @max_dma_count: Maximum DMA transfer count supported by DMA controller.
+ * @hw_support_pause: DMA HW engine support pause of the channel.
+ */
+struct tegra_dma_chip_data {
+       int nr_channels;
+       int channel_reg_size;
+       int max_dma_count;
+       bool hw_support_pause;
+};
+
+/* DMA channel registers */
+struct tegra_dma_channel_regs {
+       unsigned long csr;
+       unsigned long src_ptr;
+       unsigned long dst_ptr;
+       unsigned long high_addr_ptr;
+       unsigned long mc_seq;
+       unsigned long mmio_seq;
+       unsigned long wcount;
+       unsigned long fixed_pattern;
+};
+
+/*
+ * 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;
+       struct list_head node;
+       struct tegra_dma_desc *dma_desc;
+};
+
+/*
+ * tegra_dma_desc: Tegra DMA descriptors which uses virt_dma_desc to
+ * manage client request and keep track of transfer status, callbacks
+ * and request counts etc.
+ */
+struct tegra_dma_desc {
+       struct virt_dma_desc vd;
+       int bytes_requested;
+       int bytes_transferred;
+       struct tegra_dma_channel *tdc;
+};
+
+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 {
+       struct virt_dma_chan vc;
+       struct tegra_dma_desc *dma_desc;
+       struct tegra_dma_desc *pending_dma_desc;
+       char name[30];
+       bool config_init;
+       int id;
+       int irq;
+       unsigned long chan_base_offset;
+       raw_spinlock_t lock;
+       bool busy;
+       bool is_pending;
+       struct tegra_dma *tdma;
+       struct list_head pending_sg_req;
+       dma_isr_handler isr_handler;
+       int slave_id;
+       struct dma_slave_config dma_sconfig;
+       struct tegra_dma_channel_regs channel_reg;
+};
+
+/*
+ * tegra_dma: Tegra DMA specific information
+ */
+struct tegra_dma {
+       struct dma_device dma_dev;
+       struct device *dev;
+       void __iomem *base_addr;
+       const struct tegra_dma_chip_data *chip_data;
+       struct reset_control *rst;
+       struct tegra_dma_channel channels[0];
+};
+
+static inline void tdc_write(struct tegra_dma_channel *tdc,
+                            u32 reg, u32 val)
+{
+       writel_relaxed(val, tdc->tdma->base_addr + tdc->chan_base_offset + reg);
+}
+
+static inline u32 tdc_read(struct tegra_dma_channel *tdc, u32 reg)
+{
+       return readl_relaxed(tdc->tdma->base_addr + tdc->chan_base_offset + 
reg);
+}
+
+static inline struct tegra_dma_channel *to_tegra_dma_chan(struct dma_chan *dc)
+{
+       return container_of(dc, struct tegra_dma_channel, vc.chan);
+}
+
+static inline struct tegra_dma_desc *vd_to_tegra_dma_desc(struct virt_dma_desc 
*vd)
+{
+       return container_of(vd, struct tegra_dma_desc, vd);
+}
+
+static inline struct device *tdc2dev(struct tegra_dma_channel *tdc)
+{
+       return tdc->vc.chan.device->dev;
+}
+
+static void tegra_dma_dump_chan_regs(struct tegra_dma_channel *tdc)
+{
+       pr_info("DMA Channel %d name %s register dump:\n",
+               tdc->id, tdc->name);
+       pr_info("CSR %x STA %x CSRE %x SRC %x DST %x\n",
+               tdc_read(tdc, TEGRA_GPCDMA_CHAN_CSR),
+               tdc_read(tdc, TEGRA_GPCDMA_CHAN_STATUS),
+               tdc_read(tdc, TEGRA_GPCDMA_CHAN_CSRE),
+               tdc_read(tdc, TEGRA_GPCDMA_CHAN_SRC_PTR),
+               tdc_read(tdc, TEGRA_GPCDMA_CHAN_DST_PTR)
+       );
+       pr_info("MCSEQ %x IOSEQ %x WCNT %x XFER %x BSTA %x\n",
+               tdc_read(tdc, TEGRA_GPCDMA_CHAN_MCSEQ),
+               tdc_read(tdc, TEGRA_GPCDMA_CHAN_MMIOSEQ),
+               tdc_read(tdc, TEGRA_GPCDMA_CHAN_WCOUNT),
+               tdc_read(tdc, TEGRA_GPCDMA_CHAN_XFER_COUNT),
+               tdc_read(tdc, TEGRA_GPCDMA_CHAN_DMA_BYTE_STATUS)
+       );
+       pr_info("DMA ERR_STA %x\n",
+               tdc_read(tdc, TEGRA_GPCDMA_CHAN_ERR_STATUS));
+}
+
+static void tegra_dma_desc_free(struct virt_dma_desc *vd)
+{
+       struct tegra_dma_desc *dma_desc = vd_to_tegra_dma_desc(vd);
+       struct tegra_dma_channel *tdc = dma_desc->tdc;
+       unsigned long flags;
+
+       if (!dma_desc)
+               return;
+       raw_spin_lock_irqsave(&tdc->lock, flags);
+       kfree(dma_desc);
+       raw_spin_unlock_irqrestore(&tdc->lock, flags);
+}
+
+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), "Configuration not allowed\n");
+               return -EBUSY;
+       }
+
+       memcpy(&tdc->dma_sconfig, sconfig, sizeof(*sconfig));
+       if (tdc->slave_id == -1)
+               tdc->slave_id = sconfig->slave_id;
+       tdc->config_init = true;
+       return 0;
+}
+
+static int tegra_dma_pause(struct tegra_dma_channel *tdc)
+{
+       u32 val;
+       int ret;
+
+       tdc_write(tdc, TEGRA_GPCDMA_CHAN_CSRE, TEGRA_GPCDMA_CHAN_CSRE_PAUSE);
+
+       /* Wait until busy bit is de-asserted */
+       ret = readl_relaxed_poll_timeout_atomic(tdc->tdma->base_addr +
+                       tdc->chan_base_offset + TEGRA_GPCDMA_CHAN_STATUS,
+                       val,
+                       !(val & TEGRA_GPCDMA_STATUS_BUSY),
+                       TEGRA_GPCDMA_BURST_COMPLETE_TIME,
+                       TEGRA_GPCDMA_BURST_COMPLETION_TIMEOUT);
+
+       if (ret) {
+               dev_err(tdc2dev(tdc), "DMA pause timed out\n");
+               return ret;
+       }
+
+       return ret;
+}
+
+static void tegra_dma_stop(struct tegra_dma_channel *tdc)
+{
+       u32 csr, status;
+
+       csr = tdc_read(tdc, TEGRA_GPCDMA_CHAN_CSR);
+
+       /* Disable interrupts */
+       csr &= ~TEGRA_GPCDMA_CSR_IE_EOC;
+
+       /* Disable DMA */
+       csr &= ~TEGRA_GPCDMA_CSR_ENB;
+       tdc_write(tdc, TEGRA_GPCDMA_CHAN_CSR, csr);
+
+       /* Clear interrupt status if it is there */
+       status = tdc_read(tdc, TEGRA_GPCDMA_CHAN_STATUS);
+       if (status & TEGRA_GPCDMA_STATUS_ISE_EOC) {
+               dev_dbg(tdc2dev(tdc), "%s():clearing interrupt\n", __func__);
+               tdc_write(tdc, TEGRA_GPCDMA_CHAN_STATUS, 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;
+
+       tdc_write(tdc, TEGRA_GPCDMA_CHAN_WCOUNT, ch_regs->wcount);
+
+       tdc_write(tdc, TEGRA_GPCDMA_CHAN_CSR, 0);
+       tdc_write(tdc, TEGRA_GPCDMA_CHAN_SRC_PTR, ch_regs->src_ptr);
+       tdc_write(tdc, TEGRA_GPCDMA_CHAN_DST_PTR, ch_regs->dst_ptr);
+       tdc_write(tdc, TEGRA_GPCDMA_CHAN_HIGH_ADDR_PTR, ch_regs->high_addr_ptr);
+       tdc_write(tdc, TEGRA_GPCDMA_CHAN_FIXED_PATTERN, ch_regs->fixed_pattern);
+       tdc_write(tdc, TEGRA_GPCDMA_CHAN_MMIOSEQ, ch_regs->mmio_seq);
+       tdc_write(tdc, TEGRA_GPCDMA_CHAN_MCSEQ, ch_regs->mc_seq);
+       tdc_write(tdc, TEGRA_GPCDMA_CHAN_CSRE, 0);
+       tdc_write(tdc, TEGRA_GPCDMA_CHAN_CSR, ch_regs->csr);
+
+       /* Start DMA */
+       tdc_write(tdc, TEGRA_GPCDMA_CHAN_CSR,
+                 ch_regs->csr | TEGRA_GPCDMA_CSR_ENB);
+}
+
+static void tdc_start_head_req(struct tegra_dma_channel *tdc)
+{
+       struct tegra_dma_sg_req *sg_req;
+       struct virt_dma_desc *vdesc;
+
+       if (list_empty(&tdc->pending_sg_req))
+               return;
+
+       if (tdc->is_pending)
+               return;
+
+       vdesc = vchan_next_desc(&tdc->vc);
+       if (!vdesc)
+               return;
+       list_del(&vdesc->node);
+       tdc->dma_desc = vd_to_tegra_dma_desc(vdesc);
+       tdc->is_pending = true;
+       tdc->dma_desc->tdc = tdc;
+       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 tegra_dma_abort_all(struct tegra_dma_channel *tdc)
+{
+       struct tegra_dma_sg_req *sgreq;
+
+       while (!list_empty(&tdc->pending_sg_req)) {
+               sgreq = list_first_entry(&tdc->pending_sg_req,
+                                        typeof(*sgreq), node);
+               list_del(&sgreq->node);
+               kfree(sgreq);
+       }
+       tdc->isr_handler = NULL;
+}
+
+static void handle_once_dma_done(struct tegra_dma_channel *tdc,
+                                bool to_terminate)
+{
+       struct tegra_dma_desc *dma_desc;
+       struct tegra_dma_sg_req *sgreq;
+
+       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;
+
+       if (sgreq->last_sg) {
+               vchan_cookie_complete(&tdc->dma_desc->vd);
+               tdc->is_pending = false;
+               tdc->dma_desc = NULL;
+       }
+       list_del(&sgreq->node);
+       kfree(sgreq);
+
+       if (to_terminate || list_empty(&tdc->pending_sg_req))
+               return;
+
+       tdc_start_head_req(tdc);
+}
+
+static void tegra_dma_chan_decode_error(struct tegra_dma_channel *tdc,
+                                       unsigned int err_status)
+{
+       switch (TEGRA_GPCDMA_CHAN_ERR_TYPE(err_status)) {
+       case TEGRA_DMA_BM_FIFO_FULL_ERR:
+               dev_err(tdc->tdma->dev,
+                       "GPCDMA CH%d bm fifo full\n", tdc->id);
+               break;
+
+       case TEGRA_DMA_PERIPH_FIFO_FULL_ERR:
+               dev_err(tdc->tdma->dev,
+                       "GPCDMA CH%d peripheral fifo full\n", tdc->id);
+               break;
+
+       case TEGRA_DMA_PERIPH_ID_ERR:
+               dev_err(tdc->tdma->dev,
+                       "GPCDMA CH%d illegal peripheral id\n", tdc->id);
+               break;
+
+       case TEGRA_DMA_STREAM_ID_ERR:
+               dev_err(tdc->tdma->dev,
+                       "GPCDMA CH%d illegal stream id\n", tdc->id);
+               break;
+
+       case TEGRA_DMA_MC_SLAVE_ERR:
+               dev_err(tdc->tdma->dev,
+                       "GPCDMA CH%d mc slave error\n", tdc->id);
+               break;
+
+       case TEGRA_DMA_MMIO_SLAVE_ERR:
+               dev_err(tdc->tdma->dev,
+                       "GPCDMA CH%d mmio slave error\n", tdc->id);
+               break;
+
+       default:
+               dev_err(tdc->tdma->dev,
+                       "GPCDMA CH%d security violation %x\n", tdc->id,
+                       err_status);
+       }
+}
+
+static irqreturn_t tegra_dma_isr(int irq, void *dev_id)
+{
+       struct tegra_dma_channel *tdc = dev_id;
+       unsigned int err_status;
+       unsigned long status;
+
+       raw_spin_lock(&tdc->lock);
+
+       status = tdc_read(tdc, TEGRA_GPCDMA_CHAN_STATUS);
+       err_status = tdc_read(tdc, TEGRA_GPCDMA_CHAN_ERR_STATUS);
+
+       if (err_status) {
+               tegra_dma_chan_decode_error(tdc, err_status);
+               tegra_dma_dump_chan_regs(tdc);
+               tdc_write(tdc, TEGRA_GPCDMA_CHAN_ERR_STATUS, 0xFFFFFFFF);
+       }
+
+       if (status & TEGRA_GPCDMA_STATUS_ISE_EOC) {
+               tdc_write(tdc, TEGRA_GPCDMA_CHAN_STATUS,
+                         TEGRA_GPCDMA_STATUS_ISE_EOC);
+               if (tdc->isr_handler) {
+                       tdc->isr_handler(tdc, false);
+               } else {
+                       dev_err(tdc->tdma->dev,
+                               "GPCDMA CH%d: status %lx ISR handler absent!\n",
+                               tdc->id, status);
+                       tegra_dma_dump_chan_regs(tdc);
+               }
+               raw_spin_unlock(&tdc->lock);
+               return IRQ_HANDLED;
+       }
+
+       raw_spin_unlock(&tdc->lock);
+       return IRQ_NONE;
+}
+
+static void tegra_dma_issue_pending(struct dma_chan *dc)
+{
+       struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
+       unsigned long flags;
+
+       raw_spin_lock_irqsave(&tdc->lock, flags);
+       if (list_empty(&tdc->pending_sg_req)) {
+               dev_err(tdc2dev(tdc), "No DMA request\n");
+               goto end;
+       }
+
+       if (!tdc->busy)
+               if (vchan_issue_pending(&tdc->vc))
+                       tdc_start_head_req(tdc);
+
+end:
+       raw_spin_unlock_irqrestore(&tdc->lock, flags);
+}
+
+static void tegra_dma_reset_client(struct tegra_dma_channel *tdc)
+{
+       u32 csr = tdc_read(tdc, TEGRA_GPCDMA_CHAN_CSR);
+
+       csr &= ~(TEGRA_GPCDMA_CSR_REQ_SEL_MASK);
+       csr |= TEGRA_GPCDMA_CSR_REQ_SEL_UNUSED;
+       tdc_write(tdc, TEGRA_GPCDMA_CHAN_CSR, csr);
+}
+
+static int tegra_dma_terminate_all(struct dma_chan *dc)
+{
+       struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
+       struct tegra_dma_sg_req *sgreq;
+       unsigned long wcount = 0;
+       unsigned long status;
+       unsigned long flags;
+       bool was_busy;
+       int err;
+
+       raw_spin_lock_irqsave(&tdc->lock, flags);
+       if (list_empty(&tdc->pending_sg_req)) {
+               raw_spin_unlock_irqrestore(&tdc->lock, flags);
+               return 0;
+       }
+
+       if (!tdc->busy)
+               goto skip_dma_stop;
+
+       if (tdc->tdma->chip_data->hw_support_pause) {
+               err = tegra_dma_pause(tdc);
+               if (err) {
+                       raw_spin_unlock_irqrestore(&tdc->lock, flags);
+                       return err;
+               }
+       } else {
+               /* Before Reading DMA status to figure out number
+                * of bytes transferred by DMA channel:
+                * Change the client associated with the DMA channel
+                * to stop DMA engine from starting any more bursts for
+                * the given client and wait for in flight bursts to complete
+                */
+               tegra_dma_reset_client(tdc);
+
+               /* Wait for in flight data transfer to finish */
+               udelay(TEGRA_GPCDMA_BURST_COMPLETE_TIME);
+
+               /* If TX/RX path is still active wait till it becomes
+                * inactive
+                */
+
+               if (readl_relaxed_poll_timeout_atomic(tdc->tdma->base_addr +
+                               tdc->chan_base_offset +
+                               TEGRA_GPCDMA_CHAN_STATUS,
+                               status,
+                               !(status & (TEGRA_GPCDMA_STATUS_CHANNEL_TX |
+                               TEGRA_GPCDMA_STATUS_CHANNEL_RX)),
+                               5,
+                               TEGRA_GPCDMA_BURST_COMPLETION_TIMEOUT)) {
+                       dev_err(tdc2dev(tdc), "Timeout waiting for DMA burst 
completion!\n");
+                       tegra_dma_dump_chan_regs(tdc);
+               }
+       }
+
+       status = tdc_read(tdc, TEGRA_GPCDMA_CHAN_STATUS);
+       wcount = tdc_read(tdc, TEGRA_GPCDMA_CHAN_XFER_COUNT);
+       if (status & TEGRA_GPCDMA_STATUS_ISE_EOC) {
+               dev_dbg(tdc2dev(tdc), "%s():handling isr\n", __func__);
+               tdc->isr_handler(tdc, true);
+               status = tdc_read(tdc, TEGRA_GPCDMA_CHAN_STATUS);
+               wcount = tdc_read(tdc, TEGRA_GPCDMA_CHAN_XFER_COUNT);
+       }
+
+       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 +=
+                       sgreq->req_len - (wcount * 4);
+       }
+
+skip_dma_stop:
+       tegra_dma_abort_all(tdc);
+       vchan_free_chan_resources(&tdc->vc);
+       if (tdc->is_pending) {
+               tdc->pending_dma_desc = tdc->dma_desc;
+               tdc->is_pending = false;
+               tdc->dma_desc = NULL;
+       }
+
+       raw_spin_unlock_irqrestore(&tdc->lock, flags);
+       return 0;
+}
+
+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;
+       unsigned int residual;
+       enum dma_status ret;
+       unsigned long flags;
+
+       raw_spin_lock_irqsave(&tdc->lock, flags);
+
+       ret = dma_cookie_status(dc, cookie, txstate);
+       if (ret == DMA_COMPLETE) {
+               raw_spin_unlock_irqrestore(&tdc->lock, flags);
+               return ret;
+       }
+
+       /*
+        * Incase if dma client terminate the request and triggers tx_status
+        * before the dma completion then free pending dma desc if exist
+        */
+       if (tdc->pending_dma_desc) {
+               dma_desc = tdc->pending_dma_desc;
+               tdc->pending_dma_desc = NULL;
+               if (dma_desc->vd.tx.cookie == cookie) {
+                       residual =  dma_desc->bytes_requested -
+                                       (dma_desc->bytes_transferred %
+                                               dma_desc->bytes_requested);
+                       dma_set_residue(txstate, residual);
+                       kfree(dma_desc);
+                       raw_spin_unlock_irqrestore(&tdc->lock, flags);
+                       return ret;
+               }
+       }
+
+       /* Check in pending list */
+       list_for_each_entry(sg_req, &tdc->pending_sg_req, node) {
+               dma_desc = sg_req->dma_desc;
+               if (dma_desc->vd.tx.cookie == cookie) {
+                       residual =  dma_desc->bytes_requested -
+                                       (dma_desc->bytes_transferred %
+                                               dma_desc->bytes_requested);
+                       dma_set_residue(txstate, residual);
+                       raw_spin_unlock_irqrestore(&tdc->lock, flags);
+                       return ret;
+               }
+       }
+
+       dev_dbg(tdc2dev(tdc), "cookie %d does not found\n", cookie);
+       raw_spin_unlock_irqrestore(&tdc->lock, flags);
+       return ret;
+}
+
+static inline int get_bus_width(struct tegra_dma_channel *tdc,
+                               enum dma_slave_buswidth slave_bw)
+{
+       switch (slave_bw) {
+       case DMA_SLAVE_BUSWIDTH_1_BYTE:
+               return TEGRA_GPCDMA_MMIOSEQ_BUS_WIDTH_8;
+       case DMA_SLAVE_BUSWIDTH_2_BYTES:
+               return TEGRA_GPCDMA_MMIOSEQ_BUS_WIDTH_16;
+       case DMA_SLAVE_BUSWIDTH_4_BYTES:
+               return TEGRA_GPCDMA_MMIOSEQ_BUS_WIDTH_32;
+       case DMA_SLAVE_BUSWIDTH_8_BYTES:
+               return TEGRA_GPCDMA_MMIOSEQ_BUS_WIDTH_64;
+       default:
+               dev_warn(tdc2dev(tdc),
+                        "slave bw is not supported, using 32bits\n");
+               return TEGRA_GPCDMA_MMIOSEQ_BUS_WIDTH_32;
+       }
+}
+
+static inline int get_burst_size(struct tegra_dma_channel *tdc,
+                                u32 burst_size,
+                                enum dma_slave_buswidth slave_bw,
+                                int len)
+{
+       int burst_mmio_width;
+       int burst_byte;
+
+       /*
+        * burst_size from client is in terms of the bus_width.
+        * convert that into words.
+        */
+       burst_byte = burst_size * slave_bw;
+       burst_mmio_width = burst_byte / 4;
+
+       /* If burst size is 0 then calculate the burst size based on length */
+       if (!burst_mmio_width) {
+               if (len & 0xF)
+                       return TEGRA_GPCDMA_MMIOSEQ_BURST_1;
+               else if ((len >> 3) & 0x1)
+                       return TEGRA_GPCDMA_MMIOSEQ_BURST_2;
+               else if ((len >> 4) & 0x1)
+                       return TEGRA_GPCDMA_MMIOSEQ_BURST_4;
+               else if ((len >> 5) & 0x1)
+                       return TEGRA_GPCDMA_MMIOSEQ_BURST_8;
+               else
+                       return TEGRA_GPCDMA_MMIOSEQ_BURST_16;
+       }
+       if (burst_mmio_width < 2)
+               return TEGRA_GPCDMA_MMIOSEQ_BURST_1;
+       else if (burst_mmio_width < 4)
+               return TEGRA_GPCDMA_MMIOSEQ_BURST_2;
+       else if (burst_mmio_width < 8)
+               return TEGRA_GPCDMA_MMIOSEQ_BURST_4;
+       else if (burst_mmio_width < 16)
+               return TEGRA_GPCDMA_MMIOSEQ_BURST_8;
+       else
+               return TEGRA_GPCDMA_MMIOSEQ_BURST_16;
+}
+
+static int get_transfer_param(struct tegra_dma_channel *tdc,
+                             enum dma_transfer_direction direction,
+                                 unsigned long *apb_addr,
+                             unsigned long *mmio_seq,
+                                 unsigned long *csr,
+                             unsigned int *burst_size,
+                             enum dma_slave_buswidth *slave_bw)
+{
+       switch (direction) {
+       case DMA_MEM_TO_DEV:
+               *apb_addr = tdc->dma_sconfig.dst_addr;
+               *mmio_seq = get_bus_width(tdc, tdc->dma_sconfig.dst_addr_width);
+               *burst_size = tdc->dma_sconfig.dst_maxburst;
+               *slave_bw = tdc->dma_sconfig.dst_addr_width;
+               *csr = TEGRA_GPCDMA_CSR_DMA_MEM2IO_FC;
+               return 0;
+
+       case DMA_DEV_TO_MEM:
+               *apb_addr = tdc->dma_sconfig.src_addr;
+               *mmio_seq = get_bus_width(tdc, tdc->dma_sconfig.src_addr_width);
+               *burst_size = tdc->dma_sconfig.src_maxburst;
+               *slave_bw = tdc->dma_sconfig.src_addr_width;
+               *csr = TEGRA_GPCDMA_CSR_DMA_IO2MEM_FC;
+               return 0;
+       case DMA_MEM_TO_MEM:
+               *burst_size = tdc->dma_sconfig.src_addr_width;
+               *csr = TEGRA_GPCDMA_CSR_DMA_MEM2MEM;
+               return 0;
+       default:
+               dev_err(tdc2dev(tdc), "Dma direction is not supported\n");
+               return -EINVAL;
+       }
+       return -EINVAL;
+}
+
+static struct dma_async_tx_descriptor *tegra_dma_prep_dma_memset(
+       struct dma_chan *dc, dma_addr_t dest, int value, size_t len,
+       unsigned long flags)
+{
+       struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
+       struct tegra_dma_sg_req *sg_req = NULL;
+       struct tegra_dma_desc *dma_desc;
+       struct list_head req_list;
+       unsigned long csr, mc_seq;
+
+       INIT_LIST_HEAD(&req_list);
+       /* Set dma mode to fixed pattern */
+       csr = TEGRA_GPCDMA_CSR_DMA_FIXED_PAT;
+       /* Enable once or continuous mode */
+       csr |= TEGRA_GPCDMA_CSR_ONCE;
+       /* Enable IRQ mask */
+       csr |= TEGRA_GPCDMA_CSR_IRQ_MASK;
+       /* Enable the dma interrupt */
+       if (flags & DMA_PREP_INTERRUPT)
+               csr |= TEGRA_GPCDMA_CSR_IE_EOC;
+       /* Configure default priority weight for the channel */
+       csr |= (1 << TEGRA_GPCDMA_CSR_WEIGHT_SHIFT);
+
+       mc_seq =  tdc_read(tdc, TEGRA_GPCDMA_CHAN_MCSEQ);
+       /* retain stream-id and clean rest */
+       mc_seq &= (TEGRA_GPCDMA_MCSEQ_STREAM_ID_MASK <<
+                       TEGRA_GPCDMA_MCSEQ_STREAM_ID0_SHIFT);
+
+       /* Set the address wrapping */
+       mc_seq |= TEGRA_GPCDMA_MCSEQ_WRAP_NONE <<
+                       TEGRA_GPCDMA_MCSEQ_WRAP0_SHIFT;
+       mc_seq |= TEGRA_GPCDMA_MCSEQ_WRAP_NONE <<
+                       TEGRA_GPCDMA_MCSEQ_WRAP1_SHIFT;
+
+       /* Program outstanding MC requests */
+       mc_seq |= (1 << TEGRA_GPCDMA_MCSEQ_REQ_COUNT_SHIFT);
+       /* Set burst size */
+       mc_seq |= TEGRA_GPCDMA_MCSEQ_BURST_16;
+
+       dma_desc = kzalloc(sizeof(struct tegra_dma_desc), GFP_NOWAIT);
+       if (!dma_desc)
+               return NULL;
+
+       dma_desc->bytes_requested = 0;
+       dma_desc->bytes_transferred = 0;
+
+       if ((len & 3) || (dest & 3) ||
+           len > tdc->tdma->chip_data->max_dma_count) {
+               dev_err(tdc2dev(tdc),
+                       "Dma length/memory address is not supported\n");
+               kfree(dma_desc);
+               return NULL;
+       }
+
+       sg_req = kzalloc(sizeof(struct tegra_dma_sg_req), GFP_NOWAIT);
+       if (!sg_req) {
+               kfree(dma_desc);
+               return NULL;
+       }
+
+       dma_desc->bytes_requested += len;
+       sg_req->ch_regs.src_ptr = 0;
+       sg_req->ch_regs.dst_ptr = dest;
+       sg_req->ch_regs.high_addr_ptr = ((dest >> 32) &
+                       TEGRA_GPCDMA_HIGH_ADDR_DST_PTR_MASK) <<
+                       TEGRA_GPCDMA_HIGH_ADDR_DST_PTR_SHIFT;
+       sg_req->ch_regs.fixed_pattern = value;
+       /* Word count reg takes value as (N +1) words */
+       sg_req->ch_regs.wcount = ((len - 4) >> 2);
+       sg_req->ch_regs.csr = csr;
+       sg_req->ch_regs.mmio_seq = 0;
+       sg_req->ch_regs.mc_seq = mc_seq;
+       sg_req->configured = false;
+       sg_req->last_sg = false;
+       sg_req->dma_desc = dma_desc;
+       sg_req->req_len = len;
+       sg_req->last_sg = true;
+
+       list_add_tail(&sg_req->node, &tdc->pending_sg_req);
+
+       if (!tdc->isr_handler)
+               tdc->isr_handler = handle_once_dma_done;
+
+       tdc->pending_dma_desc = NULL;
+
+       return vchan_tx_prep(&tdc->vc, &dma_desc->vd, flags);
+}
+
+static struct dma_async_tx_descriptor *tegra_dma_prep_dma_memcpy(
+       struct dma_chan *dc, dma_addr_t dest, dma_addr_t src,   size_t len,
+       unsigned long flags)
+{
+       struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
+       struct tegra_dma_sg_req *sg_req = NULL;
+       struct tegra_dma_desc *dma_desc;
+       struct list_head req_list;
+       unsigned long csr, mc_seq;
+
+       INIT_LIST_HEAD(&req_list);
+       /* Set dma mode to memory to memory transfer */
+       csr = TEGRA_GPCDMA_CSR_DMA_MEM2MEM;
+       /* Enable once or continuous mode */
+       csr |= TEGRA_GPCDMA_CSR_ONCE;
+       /* Enable IRQ mask */
+       csr |= TEGRA_GPCDMA_CSR_IRQ_MASK;
+       /* Enable the dma interrupt */
+       if (flags & DMA_PREP_INTERRUPT)
+               csr |= TEGRA_GPCDMA_CSR_IE_EOC;
+       /* Configure default priority weight for the channel */
+       csr |= (1 << TEGRA_GPCDMA_CSR_WEIGHT_SHIFT);
+
+       mc_seq =  tdc_read(tdc, TEGRA_GPCDMA_CHAN_MCSEQ);
+       /* retain stream-id and clean rest */
+       mc_seq &= ((TEGRA_GPCDMA_MCSEQ_STREAM_ID_MASK <<
+                               TEGRA_GPCDMA_MCSEQ_STREAM_ID0_SHIFT) |
+                       (TEGRA_GPCDMA_MCSEQ_STREAM_ID_MASK <<
+                        TEGRA_GPCDMA_MCSEQ_STREAM_ID1_SHIFT));
+
+       /* Set the address wrapping */
+       mc_seq |= TEGRA_GPCDMA_MCSEQ_WRAP_NONE <<
+                       TEGRA_GPCDMA_MCSEQ_WRAP0_SHIFT;
+       mc_seq |= TEGRA_GPCDMA_MCSEQ_WRAP_NONE <<
+                       TEGRA_GPCDMA_MCSEQ_WRAP1_SHIFT;
+
+       /* Program outstanding MC requests */
+       mc_seq |= (1 << TEGRA_GPCDMA_MCSEQ_REQ_COUNT_SHIFT);
+       /* Set burst size */
+       mc_seq |= TEGRA_GPCDMA_MCSEQ_BURST_16;
+
+       dma_desc = kzalloc(sizeof(struct tegra_dma_desc), GFP_NOWAIT);
+       if (!dma_desc)
+               return NULL;
+
+       dma_desc->bytes_requested = 0;
+       dma_desc->bytes_transferred = 0;
+
+       if ((len & 3) || (src & 3) || (dest & 3) ||
+           len > tdc->tdma->chip_data->max_dma_count) {
+               dev_err(tdc2dev(tdc),
+                       "Dma length/memory address is not supported\n");
+               kfree(dma_desc);
+               return NULL;
+       }
+
+       sg_req = kzalloc(sizeof(struct tegra_dma_sg_req), GFP_NOWAIT);
+       if (!sg_req) {
+               kfree(dma_desc);
+               return NULL;
+       }
+
+       dma_desc->bytes_requested += len;
+       sg_req->ch_regs.src_ptr = src;
+       sg_req->ch_regs.dst_ptr = dest;
+       sg_req->ch_regs.high_addr_ptr = (src >> 32) &
+               TEGRA_GPCDMA_HIGH_ADDR_SCR_PTR_MASK;
+       sg_req->ch_regs.high_addr_ptr |= ((dest >> 32) &
+               TEGRA_GPCDMA_HIGH_ADDR_DST_PTR_MASK) <<
+               TEGRA_GPCDMA_HIGH_ADDR_DST_PTR_SHIFT;
+       /* Word count reg takes value as (N +1) words */
+       sg_req->ch_regs.wcount = ((len - 4) >> 2);
+       sg_req->ch_regs.csr = csr;
+       sg_req->ch_regs.mmio_seq = 0;
+       sg_req->ch_regs.mc_seq = mc_seq;
+       sg_req->configured = false;
+       sg_req->last_sg = false;
+       sg_req->dma_desc = dma_desc;
+       sg_req->req_len = len;
+       sg_req->last_sg = true;
+
+       list_add_tail(&sg_req->node, &tdc->pending_sg_req);
+
+       if (!tdc->isr_handler)
+               tdc->isr_handler = handle_once_dma_done;
+
+       tdc->pending_dma_desc = NULL;
+
+       return vchan_tx_prep(&tdc->vc, &dma_desc->vd, flags);
+}
+
+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);
+       unsigned long csr, mc_seq, apb_ptr = 0, mmio_seq = 0;
+       struct tegra_dma_sg_req *sg_req = NULL;
+       enum dma_slave_buswidth slave_bw;
+       struct tegra_dma_desc *dma_desc;
+       struct list_head req_list;
+       struct scatterlist *sg;
+       u32 burst_size;
+       unsigned int i;
+       int ret;
+
+       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;
+       }
+
+       ret = get_transfer_param(tdc, direction, &apb_ptr, &mmio_seq, &csr,
+                                &burst_size, &slave_bw);
+       if (ret < 0)
+               return NULL;
+
+       INIT_LIST_HEAD(&req_list);
+
+       /* Enable once or continuous mode */
+       csr |= TEGRA_GPCDMA_CSR_ONCE;
+       /* Program the slave id in requestor select */
+       csr |= tdc->slave_id << TEGRA_GPCDMA_CSR_REQ_SEL_SHIFT;
+       /* Enable IRQ mask */
+       csr |= TEGRA_GPCDMA_CSR_IRQ_MASK;
+       /* Configure default priority weight for the channel*/
+       csr |= (1 << TEGRA_GPCDMA_CSR_WEIGHT_SHIFT);
+
+       /* Enable the dma interrupt */
+       if (flags & DMA_PREP_INTERRUPT)
+               csr |= TEGRA_GPCDMA_CSR_IE_EOC;
+
+       mc_seq =  tdc_read(tdc, TEGRA_GPCDMA_CHAN_MCSEQ);
+       /* retain stream-id and clean rest */
+       mc_seq &= (TEGRA_GPCDMA_MCSEQ_STREAM_ID_MASK <<
+                       TEGRA_GPCDMA_MCSEQ_STREAM_ID0_SHIFT);
+
+       /* Set the address wrapping on both MC and MMIO side */
+       mc_seq |= TEGRA_GPCDMA_MCSEQ_WRAP_NONE <<
+                       TEGRA_GPCDMA_MCSEQ_WRAP0_SHIFT;
+       mc_seq |= TEGRA_GPCDMA_MCSEQ_WRAP_NONE <<
+                       TEGRA_GPCDMA_MCSEQ_WRAP1_SHIFT;
+       mmio_seq |= (1 << TEGRA_GPCDMA_MMIOSEQ_WRAP_WORD_SHIFT);
+
+       /* Program 2 MC outstanding requests by default. */
+       mc_seq |= (1 << TEGRA_GPCDMA_MCSEQ_REQ_COUNT_SHIFT);
+
+       /* Setting MC burst size depending on MMIO burst size */
+       if (burst_size == 64)
+               mc_seq |= TEGRA_GPCDMA_MCSEQ_BURST_16;
+       else
+               mc_seq |= TEGRA_GPCDMA_MCSEQ_BURST_2;
+
+       dma_desc = kzalloc(sizeof(struct tegra_dma_desc), GFP_NOWAIT);
+       if (!dma_desc)
+               return NULL;
+
+       dma_desc->bytes_requested = 0;
+       dma_desc->bytes_transferred = 0;
+
+       /* Make transfer requests */
+       for_each_sg(sgl, sg, sg_len, i) {
+               u32 len;
+               dma_addr_t mem;
+
+               mem = sg_dma_address(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");
+                       kfree(dma_desc);
+                       return NULL;
+               }
+
+               sg_req = kzalloc(sizeof(struct tegra_dma_sg_req), GFP_NOWAIT);
+               if (!sg_req) {
+                       kfree(dma_desc);
+                       goto sg_alloc_error;
+               }
+
+               mmio_seq |= get_burst_size(tdc, burst_size, slave_bw, len);
+               dma_desc->bytes_requested += len;
+
+               if (direction == DMA_MEM_TO_DEV) {
+                       sg_req->ch_regs.src_ptr = mem;
+                       sg_req->ch_regs.dst_ptr = apb_ptr;
+                       sg_req->ch_regs.high_addr_ptr = (mem >> 32) &
+                               TEGRA_GPCDMA_HIGH_ADDR_SCR_PTR_MASK;
+               } else if (direction == DMA_DEV_TO_MEM) {
+                       sg_req->ch_regs.src_ptr = apb_ptr;
+                       sg_req->ch_regs.dst_ptr = mem;
+                       sg_req->ch_regs.high_addr_ptr = ((mem >> 32) &
+                               TEGRA_GPCDMA_HIGH_ADDR_DST_PTR_MASK) <<
+                               TEGRA_GPCDMA_HIGH_ADDR_DST_PTR_SHIFT;
+               }
+
+               /*
+                * Word count register takes input in words. Writing a value
+                * of N into word count register means a req of (N+1) words.
+                */
+               sg_req->ch_regs.wcount = ((len - 4) >> 2);
+               sg_req->ch_regs.csr = csr;
+               sg_req->ch_regs.mmio_seq = mmio_seq;
+               sg_req->ch_regs.mc_seq = mc_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, &tdc->pending_sg_req);
+       }
+       sg_req->last_sg = true;
+
+       /*
+        * Make sure that mode should not be conflicting with currently
+        * configured mode.
+        */
+       if (!tdc->isr_handler)
+               tdc->isr_handler = handle_once_dma_done;
+
+       tdc->pending_dma_desc = NULL;
+
+       return vchan_tx_prep(&tdc->vc, &dma_desc->vd, flags);
+
+sg_alloc_error:
+       while (!list_empty(&tdc->pending_sg_req)) {
+               sg_req = list_first_entry(&tdc->pending_sg_req,
+                                         typeof(*sg_req), node);
+               list_del(&sg_req->node);
+               kfree(sg_req);
+       }
+       return NULL;
+}
+
+static int tegra_dma_alloc_chan_resources(struct dma_chan *dc)
+{
+       struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
+
+       dma_cookie_init(&tdc->vc.chan);
+       tdc->config_init = false;
+       return 0;
+}
+
+static void tegra_dma_free_chan_resources(struct dma_chan *dc)
+{
+       struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
+       struct list_head sg_req_list;
+       unsigned long flags;
+
+       INIT_LIST_HEAD(&sg_req_list);
+
+       dev_dbg(tdc2dev(tdc), "Freeing channel %d\n", tdc->id);
+
+       if (tdc->busy)
+               tegra_dma_terminate_all(dc);
+
+       tasklet_kill(&tdc->vc.task);
+       raw_spin_lock_irqsave(&tdc->lock, flags);
+       tdc->pending_dma_desc = NULL;
+       list_splice_init(&tdc->pending_sg_req, &sg_req_list);
+       tdc->config_init = false;
+       tdc->isr_handler = NULL;
+       tdc->slave_id = -1;
+       raw_spin_unlock_irqrestore(&tdc->lock, flags);
+}
+
+static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec,
+                                          struct of_dma *ofdma)
+{
+       struct tegra_dma *tdma = ofdma->of_dma_data;
+       struct tegra_dma_channel *tdc;
+       struct dma_chan *chan;
+
+       chan = dma_get_any_slave_channel(&tdma->dma_dev);
+       if (!chan)
+               return NULL;
+
+       tdc = to_tegra_dma_chan(chan);
+       tdc->slave_id = dma_spec->args[0];
+
+       return chan;
+}
+
+static const struct tegra_dma_chip_data tegra186_dma_chip_data = {
+       .nr_channels = 32,
+       .channel_reg_size = SZ_64K,
+       .max_dma_count = SZ_1G,
+       .hw_support_pause = false,
+};
+
+static const struct tegra_dma_chip_data tegra194_dma_chip_data = {
+       .nr_channels = 32,
+       .channel_reg_size = SZ_64K,
+       .max_dma_count = SZ_1G,
+       .hw_support_pause = true,
+};
+
+static const struct of_device_id tegra_dma_of_match[] = {
+       {
+               .compatible = "nvidia,tegra186-gpcdma",
+               .data = &tegra186_dma_chip_data,
+       }, {
+               .compatible = "nvidia,tegra194-gpcdma",
+               .data = &tegra194_dma_chip_data,
+       }, {
+       },
+};
+MODULE_DEVICE_TABLE(of, tegra_dma_of_match);
+
+static int tegra_dma_program_sid(struct tegra_dma_channel *tdc,
+                                int chan, int stream_id)
+{
+       unsigned int reg_val =  tdc_read(tdc, TEGRA_GPCDMA_CHAN_MCSEQ);
+
+       reg_val &= ~(TEGRA_GPCDMA_MCSEQ_STREAM_ID_MASK <<
+                                       TEGRA_GPCDMA_MCSEQ_STREAM_ID0_SHIFT);
+       reg_val &= ~(TEGRA_GPCDMA_MCSEQ_STREAM_ID_MASK <<
+                                       TEGRA_GPCDMA_MCSEQ_STREAM_ID1_SHIFT);
+
+       reg_val |= (stream_id << TEGRA_GPCDMA_MCSEQ_STREAM_ID0_SHIFT);
+       reg_val |= (stream_id << TEGRA_GPCDMA_MCSEQ_STREAM_ID1_SHIFT);
+
+       tdc_write(tdc, TEGRA_GPCDMA_CHAN_MCSEQ, reg_val);
+       return 0;
+}
+
+static int tegra_dma_probe(struct platform_device *pdev)
+{
+       const struct tegra_dma_chip_data *cdata = NULL;
+       struct tegra_dma_chip_data *chip_data = NULL;
+       unsigned int nr_chans, stream_id;
+       unsigned int start_chan_idx = 0;
+       struct tegra_dma *tdma;
+       struct resource *res;
+       unsigned int i;
+       int ret;
+
+       if (pdev->dev.of_node) {
+               const struct of_device_id *match;
+
+               match = of_match_device(of_match_ptr(tegra_dma_of_match),
+                                       &pdev->dev);
+               if (!match) {
+                       dev_err(&pdev->dev, "Error: No device match found\n");
+                       return -ENODEV;
+               }
+               cdata = match->data;
+
+               ret = of_property_read_u32(pdev->dev.of_node, "dma-channels",
+                                          &nr_chans);
+               if (!ret) {
+                       /* Allocate chip data and update number of channels */
+                       chip_data =
+                               devm_kzalloc(&pdev->dev,
+                                            sizeof(struct tegra_dma_chip_data),
+                                                               GFP_KERNEL);
+                       if (!chip_data) {
+                               dev_err(&pdev->dev, "Error: memory allocation 
failed\n");
+                               return -ENOMEM;
+                       }
+                       memcpy(chip_data, cdata,
+                              sizeof(struct tegra_dma_chip_data));
+                       chip_data->nr_channels = nr_chans;
+                       cdata = chip_data;
+               }
+               ret = of_property_read_u32(pdev->dev.of_node,
+                                          "nvidia,start-dma-channel-index",
+                                               &start_chan_idx);
+               if (ret)
+                       start_chan_idx = 0;
+
+               ret = of_property_read_u32(pdev->dev.of_node,
+                                          "nvidia,stream-id", &stream_id);
+               if (ret)
+                       stream_id = TEGRA186_SID_GPCDMA_0;
+
+       } else {
+               /* If no device tree then fallback to chip data */
+               cdata =
+                   (struct tegra_dma_chip_data *)pdev->id_entry->driver_data;
+               stream_id = TEGRA186_SID_GPCDMA_0;
+       }
+
+       tdma = devm_kzalloc(&pdev->dev, sizeof(*tdma) + cdata->nr_channels *
+                       sizeof(struct tegra_dma_channel), GFP_KERNEL);
+       if (!tdma)
+               return -ENOMEM;
+
+       tdma->dev = &pdev->dev;
+       tdma->chip_data = cdata;
+       platform_set_drvdata(pdev, tdma);
+
+       tdma->base_addr = devm_platform_ioremap_resource(pdev, 0);
+       if (IS_ERR(tdma->base_addr))
+               return PTR_ERR(tdma->base_addr);
+
+       tdma->rst = devm_reset_control_get_exclusive(&pdev->dev, "gpcdma");
+       if (IS_ERR(tdma->rst)) {
+               if (!(PTR_ERR(tdma->rst) == -EPROBE_DEFER))
+                       dev_err(&pdev->dev, "Missing controller reset\n");
+               return PTR_ERR(tdma->rst);
+       }
+       reset_control_reset(tdma->rst);
+
+       tdma->dma_dev.dev = &pdev->dev;
+
+       INIT_LIST_HEAD(&tdma->dma_dev.channels);
+       for (i = 0; i < cdata->nr_channels; i++) {
+               struct tegra_dma_channel *tdc = &tdma->channels[i];
+
+               tdc->chan_base_offset = TEGRA_GPCDMA_CHANNEL_BASE_ADD_OFFSET +
+                               start_chan_idx * cdata->channel_reg_size +
+                                       i * cdata->channel_reg_size;
+               res = platform_get_resource(pdev, IORESOURCE_IRQ,
+                                           start_chan_idx + i);
+               if (!res) {
+                       ret = -EINVAL;
+                       dev_err(&pdev->dev, "No irq resource for chan %d\n", i);
+                       goto err_irq;
+               }
+               tdc->irq = res->start;
+               snprintf(tdc->name, sizeof(tdc->name), "gpcdma.%d", i);
+
+               tdc->tdma = tdma;
+               tdc->id = i;
+               tdc->slave_id = -1;
+
+               vchan_init(&tdc->vc, &tdma->dma_dev);
+               tdc->vc.desc_free = tegra_dma_desc_free;
+               raw_spin_lock_init(&tdc->lock);
+
+               INIT_LIST_HEAD(&tdc->pending_sg_req);
+               tdc->pending_dma_desc = NULL;
+
+               /* program stream-id for this channel */
+               tegra_dma_program_sid(tdc, i, stream_id);
+       }
+
+       dma_cap_set(DMA_SLAVE, tdma->dma_dev.cap_mask);
+       dma_cap_set(DMA_PRIVATE, tdma->dma_dev.cap_mask);
+       dma_cap_set(DMA_MEMCPY, tdma->dma_dev.cap_mask);
+       dma_cap_set(DMA_MEMSET, tdma->dma_dev.cap_mask);
+
+       /*
+        * Only word aligned transfers are supported. Set the copy
+        * alignment shift.
+        */
+       tdma->dma_dev.copy_align = 2;
+       tdma->dma_dev.fill_align = 2;
+       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_memcpy = tegra_dma_prep_dma_memcpy;
+       tdma->dma_dev.device_prep_dma_memset = tegra_dma_prep_dma_memset;
+       tdma->dma_dev.device_config = tegra_dma_slave_config;
+       tdma->dma_dev.device_terminate_all = tegra_dma_terminate_all;
+       tdma->dma_dev.device_tx_status = tegra_dma_tx_status;
+       tdma->dma_dev.device_issue_pending = tegra_dma_issue_pending;
+       tdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
+
+       /* Register DMA channel interrupt handlers after everything is setup */
+       for (i = 0; i < cdata->nr_channels; i++) {
+               struct tegra_dma_channel *tdc = &tdma->channels[i];
+
+               ret = devm_request_irq(&pdev->dev, tdc->irq,
+                                      tegra_dma_isr, 0, tdc->name, tdc);
+               if (ret) {
+                       dev_err(&pdev->dev,
+                               "request_irq failed with err %d channel %d\n",
+                               i, ret);
+                       goto err_irq;
+               }
+       }
+
+       ret = dma_async_device_register(&tdma->dma_dev);
+       if (ret < 0) {
+               dev_err(&pdev->dev,
+                       "GPC DMA driver registration failed %d\n", ret);
+               goto err_irq;
+       }
+
+       ret = of_dma_controller_register(pdev->dev.of_node,
+                                        tegra_dma_of_xlate, tdma);
+       if (ret < 0) {
+               dev_err(&pdev->dev,
+                       "GPC DMA OF registration failed %d\n", ret);
+               goto err_unregister_dma_dev;
+       }
+
+       dev_info(&pdev->dev, "GPC DMA driver register %d channels\n",
+                cdata->nr_channels);
+       return 0;
+
+err_unregister_dma_dev:
+       dma_async_device_unregister(&tdma->dma_dev);
+err_irq:
+       return ret;
+}
+
+static int tegra_dma_remove(struct platform_device *pdev)
+{
+       struct tegra_dma *tdma = platform_get_drvdata(pdev);
+
+       of_dma_controller_free(pdev->dev.of_node);
+       dma_async_device_unregister(&tdma->dma_dev);
+
+       return 0;
+}
+
+/*
+ * Save and restore csr and channel register on pm_suspend
+ * and pm_resume respectively
+ */
+static int __maybe_unused tegra_dma_pm_suspend(struct device *dev)
+{
+       struct tegra_dma *tdma = dev_get_drvdata(dev);
+       int i;
+
+       for (i = 0; i < tdma->chip_data->nr_channels; i++) {
+               struct tegra_dma_channel *tdc = &tdma->channels[i];
+               struct tegra_dma_channel_regs *ch_reg = &tdc->channel_reg;
+
+               ch_reg->csr = tdc_read(tdc, TEGRA_GPCDMA_CHAN_CSR);
+               ch_reg->src_ptr = tdc_read(tdc, TEGRA_GPCDMA_CHAN_SRC_PTR);
+               ch_reg->dst_ptr = tdc_read(tdc, TEGRA_GPCDMA_CHAN_DST_PTR);
+               ch_reg->high_addr_ptr = tdc_read(tdc,
+                                                
TEGRA_GPCDMA_CHAN_HIGH_ADDR_PTR);
+               ch_reg->mc_seq = tdc_read(tdc, TEGRA_GPCDMA_CHAN_MCSEQ);
+               ch_reg->mmio_seq = tdc_read(tdc, TEGRA_GPCDMA_CHAN_MMIOSEQ);
+               ch_reg->wcount = tdc_read(tdc, TEGRA_GPCDMA_CHAN_WCOUNT);
+       }
+       return 0;
+}
+
+static int __maybe_unused tegra_dma_pm_resume(struct device *dev)
+{
+       struct tegra_dma *tdma = dev_get_drvdata(dev);
+       int i;
+
+       for (i = 0; i < tdma->chip_data->nr_channels; i++) {
+               struct tegra_dma_channel *tdc = &tdma->channels[i];
+               struct tegra_dma_channel_regs *ch_reg = &tdc->channel_reg;
+
+               tdc_write(tdc, TEGRA_GPCDMA_CHAN_WCOUNT, ch_reg->wcount);
+               tdc_write(tdc, TEGRA_GPCDMA_CHAN_DST_PTR, ch_reg->dst_ptr);
+               tdc_write(tdc, TEGRA_GPCDMA_CHAN_SRC_PTR, ch_reg->src_ptr);
+               tdc_write(tdc, TEGRA_GPCDMA_CHAN_HIGH_ADDR_PTR,
+                         ch_reg->high_addr_ptr);
+               tdc_write(tdc, TEGRA_GPCDMA_CHAN_MMIOSEQ, ch_reg->mmio_seq);
+               tdc_write(tdc, TEGRA_GPCDMA_CHAN_MCSEQ, ch_reg->mc_seq);
+               tdc_write(tdc, TEGRA_GPCDMA_CHAN_CSR,
+                         (ch_reg->csr & ~TEGRA_GPCDMA_CSR_ENB));
+       }
+       return 0;
+}
+
+static const struct __maybe_unused dev_pm_ops tegra_dma_dev_pm_ops = {
+       SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(tegra_dma_pm_suspend, tegra_dma_pm_resume)
+};
+
+static struct platform_driver tegra_dmac_driver = {
+       .driver = {
+               .name   = "tegra-gpcdma",
+               .owner = THIS_MODULE,
+               .pm     = &tegra_dma_dev_pm_ops,
+               .of_match_table = tegra_dma_of_match,
+       },
+       .probe          = tegra_dma_probe,
+       .remove         = tegra_dma_remove,
+};
+
+module_platform_driver(tegra_dmac_driver);
+
+MODULE_ALIAS("platform:tegra-gpc-dma");
+MODULE_DESCRIPTION("NVIDIA Tegra GPC DMA Controller driver");
+MODULE_AUTHOR("Pavan Kunapuli <pkunap...@nvidia.com>");
+MODULE_AUTHOR("Rajesh Gumasta <rguma...@nvidia.com>");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4

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