[1/2] dt-bindings: dma: Add Spreadtrum SC9860 DMA controller

This patch adds the binding documentation for Spreadtrum SC9860 DMA
controller device.

Signed-off-by: Baolin Wang <baolin.wang@spreadtrum.com>
---
 Documentation/devicetree/bindings/dma/sprd-dma.txt |   41 ++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/dma/sprd-dma.txt

Hi Baolin,

On 18 July 2017 at 15:06, Baolin Wang <baolin.wang@spreadtrum.com> wrote:
> This patch adds the DMA controller driver for Spreadtrum SC9860 platform.

I guess this driver is not only for SC9860, instead it should work for
all most all Spreadtrum's platforms?

>
> Signed-off-by: Baolin Wang <baolin.wang@spreadtrum.com>
> ---
>  drivers/dma/Kconfig          |    7 +
>  drivers/dma/Makefile         |    1 +
>  drivers/dma/sprd-dma.c       | 1451 ++++++++++++++++++++++++++++++++++++++++++
>  include/linux/dma/sprd-dma.h |  270 ++++++++
>  4 files changed, 1729 insertions(+)
>  create mode 100644 drivers/dma/sprd-dma.c
>  create mode 100644 include/linux/dma/sprd-dma.h
>
> diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
> index fa8f9c0..961f6ea 100644
> --- a/drivers/dma/Kconfig
> +++ b/drivers/dma/Kconfig
> @@ -477,6 +477,13 @@ config STM32_DMA
>           If you have a board based on such a MCU and wish to use DMA say Y
>           here.
>
> +config SPRD_DMA
> +       bool "Spreadtrum DMA support"
> +       depends on ARCH_SPRD
> +       select DMA_ENGINE
> +       help
> +         Enable support for the on-chip DMA controller on Spreadtrum platform.
> +
>  config S3C24XX_DMAC
>         bool "Samsung S3C24XX DMA support"
>         depends on ARCH_S3C24XX || COMPILE_TEST
> diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
> index d12ab29..0fee561 100644
> --- a/drivers/dma/Makefile
> +++ b/drivers/dma/Makefile
> @@ -58,6 +58,7 @@ obj-$(CONFIG_RENESAS_DMA) += sh/
>  obj-$(CONFIG_SIRF_DMA) += sirf-dma.o
>  obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o
>  obj-$(CONFIG_STM32_DMA) += stm32-dma.o
> +obj-$(CONFIG_SPRD_DMA) += sprd-dma.o
>  obj-$(CONFIG_S3C24XX_DMAC) += s3c24xx-dma.o
>  obj-$(CONFIG_TXX9_DMAC) += txx9dmac.o
>  obj-$(CONFIG_TEGRA20_APB_DMA) += tegra20-apb-dma.o
> diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
> new file mode 100644
> index 0000000..64eaef7
> --- /dev/null
> +++ b/drivers/dma/sprd-dma.c
> @@ -0,0 +1,1451 @@
> +/*
> + * Copyright (C) 2017 Spreadtrum Communications Inc.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that 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.
> + */
> +

In order to keep consistent with other Spreadtrum's drivers/ DT files
that had been upstreamed, I suggest to use SPDX-License-Identifier
tag.

Thanks,
Chunyan

> +#include <linux/clk.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/dma/sprd-dma.h>
> +#include <linux/errno.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_dma.h>
> +#include <linux/of_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/slab.h>
> +
> +#include "dmaengine.h"
> +
> +#define SPRD_DMA_DESCRIPTORS           16
> +#define SPRD_DMA_CFG_COUNT             32
> +#define SPRD_DMA_CHN_REG_OFFSET                0x1000
> +#define SPRD_DMA_CHN_REG_LENGTH                0x40
> +#define SPRD_DMA_MEMCPY_MIN_SIZE       64
> +
> +/* DMA global registers definition */
> +#define DMA_GLB_PAUSE                  0x0
> +#define DMA_GLB_FRAG_WAIT              0x4
> +#define DMA_GLB_REQ_PEND0_EN           0x8
> +#define DMA_GLB_REQ_PEND1_EN           0xc
> +#define DMA_GLB_INT_RAW_STS            0x10
> +#define DMA_GLB_INT_MSK_STS            0x14
> +#define DMA_GLB_REQ_STS                        0x18
> +#define DMA_GLB_CHN_EN_STS             0x1c
> +#define DMA_GLB_DEBUG_STS              0x20
> +#define DMA_GLB_ARB_SEL_STS            0x24
> +#define DMA_GLB_CHN_START_CHN_CFG1     0x28
> +#define DMA_GLB_CHN_START_CHN_CFG2     0x2c
> +#define DMA_CHN_LLIST_OFFSET           0x10
> +#define DMA_GLB_REQ_CID(base, uid)     \
> +               ((unsigned long)(base) + 0x2000 + 0x4 * ((uid) - 1))
> +
> +/* DMA_GLB_CHN_START_CHN_CFG register definition */
> +#define SRC_CHN_OFFSET                 0
> +#define DST_CHN_OFFSET                 8
> +#define START_MODE_OFFSET              16
> +#define CHN_START_CHN                  BIT(24)
> +
> +/* DMA channel registers definition */
> +#define DMA_CHN_PAUSE                  0x0
> +#define DMA_CHN_REQ                    0x4
> +#define DMA_CHN_CFG                    0x8
> +#define DMA_CHN_INTC                   0xc
> +#define DMA_CHN_SRC_ADDR               0x10
> +#define DMA_CHN_DES_ADDR               0x14
> +#define DMA_CHN_FRG_LEN                        0x18
> +#define DMA_CHN_BLK_LEN                        0x1c
> +#define DMA_CHN_TRSC_LEN               0x20
> +#define DMA_CHN_TRSF_STEP              0x24
> +#define DMA_CHN_WARP_PTR               0x28
> +#define DMA_CHN_WARP_TO                        0x2c
> +#define DMA_CHN_LLIST_PTR              0x30
> +#define DMA_CHN_FRAG_STEP              0x34
> +#define DMA_CHN_SRC_BLK_STEP           0x38
> +#define DMA_CHN_DES_BLK_STEP           0x3c
> +
> +/* DMA_CHN_INTC register definition */
> +#define DMA_CHN_INT_MASK               GENMASK(4, 0)
> +#define DMA_CHN_INT_CLR_OFFSET         24
> +#define FRAG_INT_EN                    BIT(0)
> +#define BLK_INT_EN                     BIT(1)
> +#define TRANS_INT_EN                   BIT(2)
> +#define LIST_INT_EN                    BIT(3)
> +#define CFG_ERROR_INT_EN               BIT(4)
> +
> +/* DMA_CHN_CFG register definition */
> +#define DMA_CHN_EN                     BIT(0)
> +#define DMA_CHN_PRIORITY_OFFSET                12
> +#define LLIST_EN_OFFSET                        4
> +#define CHN_WAIT_BDONE                 24
> +#define DMA_DONOT_WAIT_BDONE           1
> +
> +/* DMA_CHN_REQ register definition */
> +#define DMA_CHN_REQ_EN                 BIT(0)
> +
> +/* DMA_CHN_PAUSE register definition */
> +#define DMA_CHN_PAUSE_EN               BIT(0)
> +#define DMA_CHN_PAUSE_STS              BIT(2)
> +#define DMA_CHN_PAUSE_CNT              0x2000
> +
> +/* DMA_CHN_WARP_* register definition */
> +#define DMA_CHN_ADDR_MASK              GENMASK(31, 28)
> +#define DMA_CHN_HIGH_ADDR_OFFSET       4
> +#define WRAP_DATA_MASK                 GENMASK(27, 0)
> +
> +/* DMA_CHN_INTC register definition */
> +#define FRAG_INT_STS                   BIT(8)
> +#define BLK_INT_STS                    BIT(9)
> +#define TRSC_INT_STS                   BIT(10)
> +#define LLIST_INT_STS                  BIT(11)
> +#define CFGERR_INT_STS                 BIT(12)
> +
> +/* DMA_CHN_FRG_LEN register definition */
> +#define SRC_DATAWIDTH_OFFSET           30
> +#define DES_DATAWIDTH_OFFSET           28
> +#define SWT_MODE_OFFSET                        26
> +#define REQ_MODE_OFFSET                        24
> +#define REQ_MODE_MASK                  0x3
> +#define ADDR_WRAP_SEL_OFFSET           23
> +#define ADDR_WRAP_EN_OFFSET            22
> +#define ADDR_FIX_SEL_OFFSET            21
> +#define ADDR_FIX_SEL_EN                        20
> +#define LLIST_END_OFFSET               19
> +#define BLK_LEN_REC_H_OFFSET           17
> +#define FRG_LEN_OFFSET                 0
> +#define FRG_LEN_MASK                   GENMASK(16, 0)
> +
> +/* DMA_CHN_BLK_LEN register definition */
> +#define BLK_LEN_MASK                   GENMASK(16, 0)
> +
> +/* DMA_CHN_TRSC_LEN register definition */
> +#define TRSC_LEN_MASK                  GENMASK(27, 0)
> +
> +/* DMA_CHN_TRSF_STEP register definition */
> +#define DEST_TRSF_STEP_OFFSET          16
> +#define SRC_TRSF_STEP_OFFSET           0
> +#define TRSF_STEP_MASK                 GENMASK(15, 0)
> +
> +/* DMA_CHN_FRAG_STEP register definition */
> +#define DEST_FRAG_STEP_OFFSET          16
> +#define SRC_FRAG_STEP_OFFSET           0
> +#define FRAG_STEP_MASK                 GENMASK(15, 0)
> +
> +/* DMA_CHN_SRC_BLK_STEP register definition */
> +#define PTR_HIGH_ADDR_MASK             GENMASK(31, 28)
> +#define PTR_HIGH_ADDR_OFFSET           4
> +
> +enum dma_config_type {
> +       SINGLE_CONFIG,
> +       LINKLIST_CONFIG,
> +};
> +
> +/* dma channel configuration */
> +struct sprd_dma_chn_config {
> +       u32 pause;
> +       u32 req;
> +       u32 cfg;
> +       u32 intc;
> +       u32 src_addr;
> +       u32 des_addr;
> +       u32 frg_len;
> +       u32 blk_len;
> +       u32 trsc_len;
> +       u32 trsf_step;
> +       u32 wrap_ptr;
> +       u32 wrap_to;
> +       u32 llist_ptr;
> +       u32 frg_step;
> +       u32 src_blk_step;
> +       u32 des_blk_step;
> +};
> +
> +/* dma request description */
> +struct sprd_dma_desc {
> +       struct dma_async_tx_descriptor  desc;
> +       struct sprd_dma_chn_config      *chn_config;
> +       struct list_head                node;
> +       enum dma_flags                  dma_flags;
> +       int                             cycle;
> +};
> +
> +/* dma channel description */
> +struct sprd_dma_chn {
> +       struct dma_chan                 chan;
> +       struct list_head                free;
> +       struct list_head                prepared;
> +       struct list_head                queued;
> +       struct list_head                active;
> +       struct list_head                completed;
> +       void __iomem                    *chn_base;
> +       spinlock_t                      chn_lock;
> +       int                             chn_num;
> +       u32                             dev_id;
> +       void                            *dma_desc_configs;
> +       struct sprd_dma_cfg             dma_cfg[SPRD_DMA_CFG_COUNT];
> +       int                             cfg_count;
> +};
> +
> +/* SPRD dma device */
> +struct sprd_dma_dev {
> +       struct dma_device               dma_dev;
> +       void __iomem                    *glb_base;
> +       struct clk                      *clk;
> +       struct clk                      *ashb_clk;
> +       int                             irq;
> +       struct tasklet_struct           tasklet;
> +       struct kmem_cache               *dma_desc_node_cachep;
> +       u32                             total_chns;
> +       struct sprd_dma_chn             channels[0];
> +};
> +
> +static bool sprd_dma_filter_fn(struct dma_chan *chan, void *param);
> +static struct of_dma_filter_info sprd_dma_info = {
> +       .filter_fn = sprd_dma_filter_fn,
> +};
> +
> +static inline struct sprd_dma_chn *to_sprd_dma_chan(struct dma_chan *c)
> +{
> +       return container_of(c, struct sprd_dma_chn, chan);
> +}
> +
> +static inline struct sprd_dma_dev *to_sprd_dma_dev(struct dma_chan *c)
> +{
> +       struct sprd_dma_chn *mchan = to_sprd_dma_chan(c);
> +
> +       return container_of(mchan, struct sprd_dma_dev, channels[c->chan_id]);
> +}
> +
> +static inline struct sprd_dma_desc *
> +to_sprd_dma_desc(struct dma_async_tx_descriptor *tx)
> +{
> +       return container_of(tx, struct sprd_dma_desc, desc);
> +}
> +
> +static int sprd_dma_enable(struct sprd_dma_dev *sdev)
> +{
> +       int ret;
> +
> +       ret = clk_prepare_enable(sdev->clk);
> +       if (ret)
> +               return ret;
> +
> +       if (!IS_ERR(sdev->ashb_clk))
> +               ret = clk_prepare_enable(sdev->ashb_clk);
> +
> +       return ret;
> +}
> +
> +static void sprd_dma_disable(struct sprd_dma_dev *sdev)
> +{
> +       clk_disable_unprepare(sdev->clk);
> +
> +       if (!IS_ERR(sdev->ashb_clk))
> +               clk_disable_unprepare(sdev->ashb_clk);
> +}
> +
> +static void sprd_dma_set_uid(struct sprd_dma_chn *mchan)
> +{
> +       struct sprd_dma_dev *sdev = to_sprd_dma_dev(&mchan->chan);
> +       u32 dev_id = mchan->dev_id;
> +
> +       if (dev_id != DMA_SOFTWARE_UID)
> +               writel(mchan->chn_num + 1, (void __iomem *)DMA_GLB_REQ_CID(
> +                      sdev->glb_base, dev_id));
> +}
> +
> +static void sprd_dma_unset_uid(struct sprd_dma_chn *mchan)
> +{
> +       struct sprd_dma_dev *sdev = to_sprd_dma_dev(&mchan->chan);
> +       u32 dev_id = mchan->dev_id;
> +
> +       if (dev_id != DMA_SOFTWARE_UID)
> +               writel(0, (void __iomem *)DMA_GLB_REQ_CID(sdev->glb_base,
> +                      dev_id));
> +}
> +
> +static void sprd_dma_clear_int(struct sprd_dma_chn *mchan)
> +{
> +       u32 intc = readl(mchan->chn_base + DMA_CHN_INTC);
> +
> +       intc |= DMA_CHN_INT_MASK << DMA_CHN_INT_CLR_OFFSET;
> +       writel(intc, mchan->chn_base + DMA_CHN_INTC);
> +}
> +
> +static void sprd_dma_enable_chn(struct sprd_dma_chn *mchan)
> +{
> +       u32 cfg = readl(mchan->chn_base + DMA_CHN_CFG);
> +
> +       cfg |= DMA_CHN_EN;
> +       writel(cfg, mchan->chn_base + DMA_CHN_CFG);
> +}
> +
> +static void sprd_dma_disable_chn(struct sprd_dma_chn *mchan)
> +{
> +       u32 cfg = readl(mchan->chn_base + DMA_CHN_CFG);
> +
> +       cfg &= ~DMA_CHN_EN;
> +       writel(cfg, mchan->chn_base + DMA_CHN_CFG);
> +}
> +
> +static void sprd_dma_soft_request(struct sprd_dma_chn *mchan)
> +{
> +       u32 req = readl(mchan->chn_base + DMA_CHN_REQ);
> +
> +       req |= DMA_CHN_REQ_EN;
> +       writel(req, mchan->chn_base + DMA_CHN_REQ);
> +}
> +
> +static void sprd_dma_stop_and_disable(struct sprd_dma_chn *mchan)
> +{
> +       u32 cfg = readl(mchan->chn_base + DMA_CHN_CFG);
> +       u32 pause, timeout = DMA_CHN_PAUSE_CNT;
> +
> +       if (!(cfg & DMA_CHN_EN))
> +               return;
> +
> +       pause = readl(mchan->chn_base + DMA_CHN_PAUSE);
> +       pause |= DMA_CHN_PAUSE_EN;
> +       writel(pause, mchan->chn_base + DMA_CHN_PAUSE);
> +
> +       do {
> +               pause = readl(mchan->chn_base + DMA_CHN_PAUSE);
> +               if (pause & DMA_CHN_PAUSE_STS)
> +                       break;
> +
> +               cpu_relax();
> +       } while (--timeout > 0);
> +
> +       sprd_dma_disable_chn(mchan);
> +       writel(0, mchan->chn_base + DMA_CHN_PAUSE);
> +}
> +
> +static unsigned long sprd_dma_get_dst_addr(struct sprd_dma_chn *mchan)
> +{
> +       unsigned long addr;
> +
> +       addr = readl(mchan->chn_base + DMA_CHN_DES_ADDR);
> +       addr |= (readl(mchan->chn_base + DMA_CHN_WARP_TO) &
> +                DMA_CHN_ADDR_MASK) << DMA_CHN_HIGH_ADDR_OFFSET;
> +       return addr;
> +}
> +
> +static enum dma_int_type sprd_dma_get_int_type(struct sprd_dma_chn *mchan)
> +{
> +       u32 intc_reg = readl(mchan->chn_base + DMA_CHN_INTC);
> +
> +       if (intc_reg & CFGERR_INT_STS)
> +               return CONFIG_ERR;
> +       else if (intc_reg & LLIST_INT_STS)
> +               return LIST_DONE;
> +       else if (intc_reg & TRSC_INT_STS)
> +               return TRANS_DONE;
> +       else if (intc_reg & BLK_INT_STS)
> +               return BLK_DONE;
> +       else if (intc_reg & FRAG_INT_STS)
> +               return FRAG_DONE;
> +       else
> +               return NO_INT;
> +}
> +
> +static enum dma_request_mode sprd_dma_get_req_type(struct sprd_dma_chn *mchan)
> +{
> +       u32 frag_reg = readl(mchan->chn_base + DMA_CHN_FRG_LEN);
> +
> +       switch ((frag_reg >> REQ_MODE_OFFSET) & REQ_MODE_MASK) {
> +       case 0:
> +               return FRAG_REQ_MODE;
> +       case 1:
> +               return BLOCK_REQ_MODE;
> +       case 2:
> +               return TRANS_REQ_MODE;
> +       case 3:
> +               return LIST_REQ_MODE;
> +       default:
> +               return FRAG_REQ_MODE;
> +       }
> +}
> +
> +static int sprd_dma_chn_start_chn(struct sprd_dma_chn *mchan,
> +                                 struct sprd_dma_desc *mdesc)
> +{
> +       struct sprd_dma_dev *sdev = to_sprd_dma_dev(&mchan->chan);
> +       enum dma_flags flag = mdesc->dma_flags;
> +       int chn = mchan->chn_num + 1;
> +       unsigned int cfg_group1, cfg_group2, start_mode = 0;
> +
> +       if (!(flag & (DMA_GROUP1_SRC | DMA_GROUP2_SRC | DMA_GROUP1_DST |
> +                     DMA_GROUP2_DST)))
> +               return 0;
> +
> +       if (flag & (DMA_GROUP1_SRC | DMA_GROUP2_SRC)) {
> +               switch (flag & (DMA_MUTL_FRAG_DONE | DMA_MUTL_BLK_DONE |
> +                       DMA_MUTL_TRANS_DONE | DMA_MUTL_LIST_DONE)) {
> +               case DMA_MUTL_FRAG_DONE:
> +                       start_mode = 0;
> +                       break;
> +               case DMA_MUTL_BLK_DONE:
> +                       start_mode = 1;
> +                       break;
> +               case DMA_MUTL_TRANS_DONE:
> +                       start_mode = 2;
> +                       break;
> +               case DMA_MUTL_LIST_DONE:
> +                       start_mode = 3;
> +                       break;
> +               default:
> +                       dev_err(sdev->dma_dev.dev,
> +                               "chn stat chn mode incorrect\n");
> +                       return -EINVAL;
> +               }
> +       }
> +
> +       cfg_group1 = readl(sdev->glb_base + DMA_GLB_CHN_START_CHN_CFG1);
> +       cfg_group2 = readl(sdev->glb_base + DMA_GLB_CHN_START_CHN_CFG2);
> +
> +       switch (flag & (DMA_GROUP1_SRC | DMA_GROUP2_SRC |
> +               DMA_GROUP1_DST | DMA_GROUP2_DST)) {
> +       case DMA_GROUP1_SRC:
> +               cfg_group1 |= chn << SRC_CHN_OFFSET;
> +               cfg_group1 |= (1 << start_mode) << START_MODE_OFFSET;
> +               cfg_group1 |= CHN_START_CHN;
> +               writel(cfg_group1, sdev->glb_base + DMA_GLB_CHN_START_CHN_CFG1);
> +               break;
> +       case DMA_GROUP2_SRC:
> +               cfg_group2 |= chn << SRC_CHN_OFFSET;
> +               cfg_group2 |= (1 << start_mode) << START_MODE_OFFSET;
> +               cfg_group2 |= CHN_START_CHN;
> +               writel(cfg_group2, sdev->glb_base + DMA_GLB_CHN_START_CHN_CFG2);
> +               break;
> +       case DMA_GROUP1_DST:
> +               cfg_group1 |= chn << DST_CHN_OFFSET;
> +               cfg_group1 |= CHN_START_CHN;
> +               writel(cfg_group1, sdev->glb_base + DMA_GLB_CHN_START_CHN_CFG1);
> +               break;
> +       case DMA_GROUP2_DST:
> +               cfg_group2 |= chn << DST_CHN_OFFSET;
> +               cfg_group2 |= CHN_START_CHN;
> +               writel(cfg_group2, sdev->glb_base + DMA_GLB_CHN_START_CHN_CFG2);
> +               break;
> +       default:
> +               break;
> +       }
> +
> +       return 0;
> +}
> +
> +static int sprd_dma_set_chn_config(struct sprd_dma_chn *mchan,
> +                                  struct sprd_dma_desc *mdesc)
> +{
> +       struct sprd_dma_chn_config *cfg = mdesc->chn_config;
> +       int ret;
> +
> +       ret = sprd_dma_chn_start_chn(mchan, mdesc);
> +       if (ret)
> +               return ret;
> +
> +       writel(cfg->pause, mchan->chn_base + DMA_CHN_PAUSE);
> +       writel(cfg->cfg, mchan->chn_base + DMA_CHN_CFG);
> +       writel(cfg->intc, mchan->chn_base + DMA_CHN_INTC);
> +       writel(cfg->src_addr, mchan->chn_base + DMA_CHN_SRC_ADDR);
> +       writel(cfg->des_addr, mchan->chn_base + DMA_CHN_DES_ADDR);
> +       writel(cfg->frg_len, mchan->chn_base + DMA_CHN_FRG_LEN);
> +       writel(cfg->blk_len, mchan->chn_base + DMA_CHN_BLK_LEN);
> +       writel(cfg->trsc_len, mchan->chn_base + DMA_CHN_TRSC_LEN);
> +       writel(cfg->trsf_step, mchan->chn_base + DMA_CHN_TRSF_STEP);
> +       writel(cfg->wrap_ptr, mchan->chn_base + DMA_CHN_WARP_PTR);
> +       writel(cfg->wrap_to, mchan->chn_base + DMA_CHN_WARP_TO);
> +       writel(cfg->llist_ptr, mchan->chn_base + DMA_CHN_LLIST_PTR);
> +       writel(cfg->frg_step, mchan->chn_base + DMA_CHN_FRAG_STEP);
> +       writel(cfg->src_blk_step, mchan->chn_base + DMA_CHN_SRC_BLK_STEP);
> +       writel(cfg->des_blk_step, mchan->chn_base + DMA_CHN_DES_BLK_STEP);
> +       writel(cfg->req, mchan->chn_base + DMA_CHN_REQ);
> +
> +       return 0;
> +}
> +
> +static int sprd_dma_start(struct sprd_dma_chn *mchan)
> +{
> +       struct sprd_dma_desc *first;
> +       int ret;
> +
> +       if (list_empty(&mchan->active))
> +               return 0;
> +
> +       /*
> +        * Get the first DMA descriptor from active list, and copy the DMA
> +        * configuration from DMA descriptor to this DMA channel.
> +        */
> +       first = list_first_entry(&mchan->active, struct sprd_dma_desc, node);
> +       ret = sprd_dma_set_chn_config(mchan, first);
> +       if (ret)
> +               return ret;
> +
> +       sprd_dma_set_uid(mchan);
> +       sprd_dma_enable_chn(mchan);
> +
> +       if (mchan->dev_id == DMA_SOFTWARE_UID &&
> +           !(first->dma_flags & (DMA_GROUP1_DST | DMA_GROUP2_DST)))
> +               sprd_dma_soft_request(mchan);
> +
> +       return 0;
> +}
> +
> +static void sprd_dma_stop(struct sprd_dma_chn *mchan)
> +{
> +       sprd_dma_unset_uid(mchan);
> +       sprd_dma_stop_and_disable(mchan);
> +       sprd_dma_clear_int(mchan);
> +}
> +
> +static int sprd_dma_process_completed(struct sprd_dma_dev *sdev)
> +{
> +       struct sprd_dma_chn *mchan;
> +       struct sprd_dma_desc *mdesc;
> +       struct sprd_dma_desc *first;
> +       struct dma_async_tx_descriptor *desc;
> +       u32 dma_total_chns = sdev->total_chns;
> +       dma_cookie_t last_cookie = 0;
> +       unsigned long flags;
> +       LIST_HEAD(list);
> +       int i;
> +
> +       for (i = 0; i < dma_total_chns; i++) {
> +               mchan = &sdev->channels[i];
> +
> +               spin_lock_irqsave(&mchan->chn_lock, flags);
> +               if (!list_empty(&mchan->completed))
> +                       list_splice_tail_init(&mchan->completed, &list);
> +               spin_unlock_irqrestore(&mchan->chn_lock, flags);
> +
> +               if (list_empty(&list))
> +                       continue;
> +
> +               list_for_each_entry(mdesc, &list, node) {
> +                       desc = &mdesc->desc;
> +
> +                       if (desc->callback)
> +                               desc->callback(desc->callback_param);
> +
> +                       dma_run_dependencies(desc);
> +                       last_cookie = desc->cookie;
> +               }
> +
> +               spin_lock_irqsave(&mchan->chn_lock, flags);
> +               list_splice_tail_init(&list, &mchan->free);
> +
> +               /*
> +                * Check if there are pending DMA descriptor in queued list
> +                * need to be queued.
> +                */
> +               if (!list_empty(&mchan->queued)) {
> +                       list_for_each_entry(mdesc, &mchan->queued, node) {
> +                               /*
> +                                * If the DMA descriptor flag is set
> +                                * DMA_GROUP1_DST or DMA_GROUP1_DST flag, which
> +                                * means this DMA descriptor do not need to be
> +                                * activated and it will be invoked by another
> +                                * DMA descriptor which set DMA_GROUP1_SRC or
> +                                * DMA_GROUP2_SRC flag.
> +                                */
> +                               if (!(mdesc->dma_flags &
> +                                     (DMA_GROUP1_DST | DMA_GROUP2_DST)) &&
> +                                   list_empty(&mchan->active)) {
> +                                       first = list_first_entry(&mchan->queued,
> +                                               struct sprd_dma_desc, node);
> +                                       list_move_tail(&first->node,
> +                                                      &mchan->active);
> +                                       sprd_dma_start(mchan);
> +                                       break;
> +                               }
> +                       }
> +               } else {
> +                       mchan->chan.completed_cookie = last_cookie;
> +               }
> +
> +               spin_unlock_irqrestore(&mchan->chn_lock, flags);
> +       }
> +
> +       return 0;
> +}
> +
> +static void sprd_dma_tasklet(unsigned long data)
> +{
> +       struct sprd_dma_dev *sdev = (void *)data;
> +
> +       sprd_dma_process_completed(sdev);
> +}
> +
> +static bool sprd_dma_check_trans_done(struct sprd_dma_desc *mdesc,
> +                                     enum dma_int_type int_type,
> +                                     enum dma_request_mode req_mode)
> +{
> +       if (mdesc->cycle == 1)
> +               return false;
> +
> +       if ((unsigned int)int_type >= ((unsigned int)req_mode + 1))
> +               return true;
> +       else
> +               return false;
> +}
> +
> +static irqreturn_t dma_irq_handle(int irq, void *dev_id)
> +{
> +       struct sprd_dma_dev *sdev = (struct sprd_dma_dev *)dev_id;
> +       u32 irq_status = readl(sdev->glb_base + DMA_GLB_INT_MSK_STS);
> +       struct sprd_dma_chn *mchan;
> +       struct sprd_dma_desc *mdesc;
> +       struct dma_async_tx_descriptor *desc;
> +       enum dma_request_mode req_type;
> +       enum dma_int_type int_type;
> +       bool trans_done = false;
> +       u32 i;
> +
> +       while (irq_status) {
> +               i = __ffs(irq_status);
> +               irq_status &= (irq_status - 1);
> +               mchan = &sdev->channels[i];
> +
> +               spin_lock(&mchan->chn_lock);
> +               int_type = sprd_dma_get_int_type(mchan);
> +               req_type = sprd_dma_get_req_type(mchan);
> +               sprd_dma_clear_int(mchan);
> +
> +               if (!list_empty(&mchan->active)) {
> +                       mdesc = list_first_entry(&mchan->active,
> +                                                struct sprd_dma_desc, node);
> +                       /*
> +                        * Check if the dma request descriptor is done, if it
> +                        * is done we should move this descriptor into
> +                        * complete list to handle.
> +                        */
> +                       trans_done = sprd_dma_check_trans_done(mdesc, int_type,
> +                                                              req_type);
> +                       if (trans_done == true)
> +                               list_splice_tail_init(&mchan->active,
> +                                                     &mchan->completed);
> +                       /*
> +                        * If the cycle is 1, which means this DMA descriptor
> +                        * will always in active state until user free this DMA
> +                        * channel's resources. But user may need to be notified
> +                        * when transfer interrupt is generated.
> +                        */
> +                       if (mdesc->cycle == 1) {
> +                               desc = &mdesc->desc;
> +                               spin_unlock(&mchan->chn_lock);
> +                               if (desc->callback)
> +                                       desc->callback(desc->callback_param);
> +                               continue;
> +                       }
> +               }
> +               spin_unlock(&mchan->chn_lock);
> +       }
> +
> +       tasklet_schedule(&sdev->tasklet);
> +       return IRQ_HANDLED;
> +}
> +
> +static dma_cookie_t sprd_desc_submit(struct dma_async_tx_descriptor *tx)
> +{
> +       struct sprd_dma_chn *mchan = to_sprd_dma_chan(tx->chan);
> +       struct sprd_dma_desc *mdesc = to_sprd_dma_desc(tx);
> +       struct sprd_dma_desc *first;
> +       unsigned long flags;
> +       dma_cookie_t cookie;
> +       int ret;
> +
> +       spin_lock_irqsave(&mchan->chn_lock, flags);
> +       cookie = dma_cookie_assign(tx);
> +       list_move_tail(&mdesc->node, &mchan->queued);
> +
> +       /*
> +        * If we set DMA_GROUP1_DST or DMA_GROUP2_DST flags, which means we do
> +        * not need start this DMA transfer and it will be invoked by other DMA
> +        * transfer setting DMA_GROUP1_SRC or DMA_GROUP2_SRC flag.
> +        */
> +       if (mdesc->dma_flags & (DMA_GROUP1_DST | DMA_GROUP2_DST)) {
> +               ret = sprd_dma_set_chn_config(mchan, mdesc);
> +               if (ret) {
> +                       spin_unlock_irqrestore(&mchan->chn_lock, flags);
> +                       return ret;
> +               }
> +
> +               sprd_dma_enable_chn(mchan);
> +       } else if (list_empty(&mchan->active)) {
> +               first = list_first_entry(&mchan->queued, struct sprd_dma_desc,
> +                                        node);
> +               list_move_tail(&first->node, &mchan->active);
> +               ret = sprd_dma_start(mchan);
> +               if (ret)
> +                       cookie = ret;
> +       }
> +       spin_unlock_irqrestore(&mchan->chn_lock, flags);
> +
> +       return cookie;
> +}
> +
> +static int sprd_dma_alloc_chan_resources(struct dma_chan *chan)
> +{
> +       struct sprd_dma_chn *mchan = to_sprd_dma_chan(chan);
> +       struct sprd_dma_dev *sdev = to_sprd_dma_dev(chan);
> +       struct sprd_dma_desc *mdesc, *tmp;
> +       struct sprd_dma_chn_config *chn_configs;
> +       LIST_HEAD(descs);
> +       unsigned long flags;
> +       int ret, i;
> +
> +       ret = pm_runtime_get_sync(chan->device->dev);
> +       if (ret < 0) {
> +               dev_err(sdev->dma_dev.dev, "pm runtime get failed: %d\n", ret);
> +               return ret;
> +       }
> +
> +       chn_configs = devm_kzalloc(sdev->dma_dev.dev,
> +                              SPRD_DMA_DESCRIPTORS *
> +                              sizeof(struct sprd_dma_chn_config),
> +                              GFP_KERNEL);
> +       if (!chn_configs) {
> +               ret = -ENOMEM;
> +               goto err_alloc;
> +       }
> +
> +       for (i = 0; i < SPRD_DMA_DESCRIPTORS; i++) {
> +               mdesc = (struct sprd_dma_desc *)kmem_cache_zalloc(
> +                                       sdev->dma_desc_node_cachep,
> +                                       GFP_ATOMIC);
> +               if (!mdesc) {
> +                       ret = -ENOMEM;
> +                       goto err_cache_alloc;
> +               }
> +
> +               dma_async_tx_descriptor_init(&mdesc->desc, chan);
> +               mdesc->desc.flags = DMA_CTRL_ACK;
> +               mdesc->desc.tx_submit = sprd_desc_submit;
> +               mdesc->chn_config = &chn_configs[i];
> +               mdesc->cycle = 0;
> +               mdesc->dma_flags = 0;
> +               INIT_LIST_HEAD(&mdesc->node);
> +               list_add_tail(&mdesc->node, &descs);
> +       }
> +
> +       spin_lock_irqsave(&mchan->chn_lock, flags);
> +       list_splice_tail_init(&descs, &mchan->free);
> +       spin_unlock_irqrestore(&mchan->chn_lock, flags);
> +
> +       mchan->dma_desc_configs = chn_configs;
> +       mchan->dev_id = 0;
> +       mchan->cfg_count = 0;
> +       memset(mchan->dma_cfg, 0, sizeof(struct sprd_dma_cfg) *
> +              SPRD_DMA_CFG_COUNT);
> +
> +       return 0;
> +
> +err_cache_alloc:
> +       list_for_each_entry_safe(mdesc, tmp, &descs, node)
> +               kmem_cache_free(sdev->dma_desc_node_cachep, mdesc);
> +       devm_kfree(sdev->dma_dev.dev, chn_configs);
> +err_alloc:
> +       pm_runtime_put_sync(chan->device->dev);
> +       return ret;
> +}
> +
> +static void sprd_dma_free_chan_resources(struct dma_chan *chan)
> +{
> +       struct sprd_dma_chn *mchan = to_sprd_dma_chan(chan);
> +       struct sprd_dma_dev *sdev = to_sprd_dma_dev(chan);
> +       struct sprd_dma_desc *mdesc, *tmp;
> +       unsigned long flags;
> +       LIST_HEAD(descs);
> +
> +       spin_lock_irqsave(&mchan->chn_lock, flags);
> +       list_splice_tail_init(&mchan->prepared, &mchan->free);
> +       list_splice_tail_init(&mchan->queued, &mchan->free);
> +       list_splice_tail_init(&mchan->active, &mchan->free);
> +       list_splice_tail_init(&mchan->completed, &mchan->free);
> +       list_splice_tail_init(&mchan->free, &descs);
> +       spin_unlock_irqrestore(&mchan->chn_lock, flags);
> +
> +       list_for_each_entry_safe(mdesc, tmp, &descs, node)
> +               kmem_cache_free(sdev->dma_desc_node_cachep, mdesc);
> +       devm_kfree(sdev->dma_dev.dev, mchan->dma_desc_configs);
> +
> +       spin_lock_irqsave(&mchan->chn_lock, flags);
> +       sprd_dma_stop(mchan);
> +       spin_unlock_irqrestore(&mchan->chn_lock, flags);
> +
> +       pm_runtime_put_sync(chan->device->dev);
> +}
> +
> +static enum dma_status sprd_dma_tx_status(struct dma_chan *chan,
> +                                         dma_cookie_t cookie,
> +                                         struct dma_tx_state *txstate)
> +{
> +       struct sprd_dma_chn *mchan = to_sprd_dma_chan(chan);
> +       unsigned long flags;
> +       enum dma_status ret;
> +
> +       ret = dma_cookie_status(chan, cookie, txstate);
> +
> +       spin_lock_irqsave(&mchan->chn_lock, flags);
> +       txstate->residue = sprd_dma_get_dst_addr(mchan);
> +       spin_unlock_irqrestore(&mchan->chn_lock, flags);
> +
> +       return ret;
> +}
> +
> +static void sprd_dma_issue_pending(struct dma_chan *chan)
> +{
> +       /*
> +        * We are posting descriptors to the hardware as soon as
> +        * they are ready, so this function does nothing.
> +        */
> +}
> +
> +static int sprd_dma_config(struct dma_chan *chan, struct sprd_dma_desc *mdesc,
> +                          struct sprd_dma_cfg *cfg_list,
> +                          struct sprd_dma_chn_config *chn_config,
> +                          enum dma_config_type type)
> +{
> +       struct sprd_dma_chn *mchan = to_sprd_dma_chan(chan);
> +       struct sprd_dma_dev *sdev = to_sprd_dma_dev(&mchan->chan);
> +       struct sprd_dma_cfg *cfg = cfg_list;
> +       struct sprd_dma_chn_config *dma_chn_config;
> +       static unsigned long first_link_p;
> +       unsigned long linklist_ptr = 0;
> +       u32 fix_mode = 0, fix_en = 0;
> +       u32 wrap_en = 0, wrap_mode = 0;
> +       u32 llist_en = 0, list_end = 0;
> +
> +       if (!IS_ALIGNED(cfg->src_step, 1 << cfg->datawidth)) {
> +               dev_err(sdev->dma_dev.dev, "source step is not aligned\n");
> +               return -EINVAL;
> +       }
> +
> +       if (!IS_ALIGNED(cfg->des_step, 1 << cfg->datawidth)) {
> +               dev_err(sdev->dma_dev.dev, "destination step is not aligned\n");
> +               return -EINVAL;
> +       }
> +
> +       if (type == SINGLE_CONFIG)
> +               dma_chn_config = mdesc->chn_config;
> +       else if (type == LINKLIST_CONFIG)
> +               dma_chn_config = chn_config;
> +       else {
> +               dev_err(sdev->dma_dev.dev,
> +                       "check configuration type failed %d\n", type);
> +               return -EINVAL;
> +       }
> +
> +       if (!mchan->dev_id)
> +               mchan->dev_id = cfg->dev_id;
> +
> +       dma_chn_config->pause = 0;
> +       dma_chn_config->req = 0;
> +
> +       if (cfg->link_cfg_p)
> +               llist_en = 1;
> +
> +       dma_chn_config->cfg = cfg->chn_pri << DMA_CHN_PRIORITY_OFFSET |
> +           llist_en << LLIST_EN_OFFSET |
> +           DMA_DONOT_WAIT_BDONE << CHN_WAIT_BDONE;
> +
> +       if (cfg->wrap_ptr && cfg->wrap_to) {
> +               wrap_en = 1;
> +               dma_chn_config->wrap_ptr = cfg->wrap_ptr & WRAP_DATA_MASK;
> +               dma_chn_config->wrap_to = cfg->wrap_to & WRAP_DATA_MASK;
> +       }
> +
> +       dma_chn_config->wrap_ptr |=
> +               (u32)((cfg->src_addr >> DMA_CHN_HIGH_ADDR_OFFSET) &
> +                     DMA_CHN_ADDR_MASK);
> +       dma_chn_config->wrap_to |=
> +               (u32)((cfg->des_addr >> DMA_CHN_HIGH_ADDR_OFFSET) &
> +                     DMA_CHN_ADDR_MASK);
> +
> +       dma_chn_config->src_addr = (u32)cfg->src_addr;
> +       dma_chn_config->des_addr = (u32)cfg->des_addr;
> +
> +       if ((cfg->src_step != 0 && cfg->des_step != 0) ||
> +           ((cfg->src_step | cfg->des_step) == 0)) {
> +               fix_en = 0;
> +       } else {
> +               fix_en = 1;
> +               if (cfg->src_step)
> +                       fix_mode = 1;
> +               else
> +                       fix_mode = 0;
> +       }
> +
> +       if (wrap_en == 1) {
> +               if (cfg->wrap_to == cfg->src_addr) {
> +                       wrap_mode = 0;
> +               } else if (cfg->wrap_to == cfg->des_addr) {
> +                       wrap_mode = 1;
> +               } else {
> +                       dev_err(sdev->dma_dev.dev,
> +                               "check wrap config failed\n");
> +                       return -EINVAL;
> +               }
> +       }
> +
> +       if (llist_en == 1 && cfg->is_end == DMA_END)
> +               list_end = 1;
> +
> +       dma_chn_config->frg_len = (cfg->datawidth << SRC_DATAWIDTH_OFFSET) |
> +               (cfg->datawidth << DES_DATAWIDTH_OFFSET) |
> +               (cfg->swt_mode << SWT_MODE_OFFSET) |
> +               (cfg->req_mode << REQ_MODE_OFFSET) |
> +               (wrap_mode << ADDR_WRAP_SEL_OFFSET) |
> +               (wrap_en << ADDR_WRAP_EN_OFFSET) |
> +               (fix_mode << ADDR_FIX_SEL_OFFSET) |
> +               (fix_en << ADDR_FIX_SEL_EN) |
> +               (list_end << LLIST_END_OFFSET) |
> +               (cfg->fragmens_len & FRG_LEN_MASK);
> +
> +       dma_chn_config->blk_len = cfg->block_len & BLK_LEN_MASK;
> +
> +       if (type == SINGLE_CONFIG) {
> +               dma_chn_config->intc &= ~DMA_CHN_INT_MASK;
> +               dma_chn_config->intc |= CFG_ERROR_INT_EN;
> +
> +               switch (cfg->irq_mode) {
> +               case NO_INT:
> +                       break;
> +               case FRAG_DONE:
> +                       dma_chn_config->intc |= FRAG_INT_EN;
> +                       break;
> +               case BLK_DONE:
> +                       dma_chn_config->intc |= BLK_INT_EN;
> +                       break;
> +               case BLOCK_FRAG_DONE:
> +                       dma_chn_config->intc |= BLK_INT_EN | FRAG_INT_EN;
> +                       break;
> +               case TRANS_DONE:
> +                       dma_chn_config->intc |= TRANS_INT_EN;
> +                       break;
> +               case TRANS_FRAG_DONE:
> +                       dma_chn_config->intc |= TRANS_INT_EN | FRAG_INT_EN;
> +                       break;
> +               case TRANS_BLOCK_DONE:
> +                       dma_chn_config->intc |= TRANS_INT_EN | BLK_INT_EN;
> +                       break;
> +               case LIST_DONE:
> +                       dma_chn_config->intc |= LIST_INT_EN;
> +                       break;
> +               case CONFIG_ERR:
> +                       dma_chn_config->intc |= CFG_ERROR_INT_EN;
> +                       break;
> +               default:
> +                       dev_err(sdev->dma_dev.dev, "irq mode failed\n");
> +                       return -EINVAL;
> +               }
> +       } else {
> +               dma_chn_config->intc = 0;
> +       }
> +
> +       if (cfg->transcation_len == 0)
> +               dma_chn_config->trsc_len = cfg->block_len & TRSC_LEN_MASK;
> +       else
> +               dma_chn_config->trsc_len = cfg->transcation_len &
> +                       TRSC_LEN_MASK;
> +
> +       dma_chn_config->trsf_step = (cfg->des_step & TRSF_STEP_MASK) <<
> +               DEST_TRSF_STEP_OFFSET |
> +               (cfg->src_step & TRSF_STEP_MASK) << SRC_TRSF_STEP_OFFSET;
> +
> +       dma_chn_config->frg_step = (cfg->dst_frag_step & FRAG_STEP_MASK)
> +               << DEST_FRAG_STEP_OFFSET |
> +               (cfg->src_frag_step & FRAG_STEP_MASK)
> +               << SRC_FRAG_STEP_OFFSET;
> +
> +       dma_chn_config->src_blk_step = cfg->src_blk_step;
> +       dma_chn_config->des_blk_step = cfg->dst_blk_step;
> +
> +       if (first_link_p == 0)
> +               first_link_p = cfg->link_cfg_p;
> +
> +       if (type == SINGLE_CONFIG) {
> +               linklist_ptr = first_link_p + DMA_CHN_LLIST_OFFSET;
> +               first_link_p = 0;
> +       } else if (type == LINKLIST_CONFIG) {
> +               if (cfg->is_end == DMA_LINK)
> +                       linklist_ptr = first_link_p + DMA_CHN_LLIST_OFFSET;
> +               else
> +                       linklist_ptr = cfg->link_cfg_p +
> +                               sizeof(struct sprd_dma_chn_config) +
> +                               DMA_CHN_LLIST_OFFSET;
> +       }
> +
> +       dma_chn_config->src_blk_step |=
> +               (u32)((linklist_ptr >> PTR_HIGH_ADDR_OFFSET) &
> +                     PTR_HIGH_ADDR_MASK);
> +       dma_chn_config->llist_ptr = (u32)linklist_ptr;
> +       return 0;
> +}
> +
> +static int sprd_dma_config_linklist(struct dma_chan *chan,
> +                                   struct sprd_dma_desc *mdesc,
> +                                   struct sprd_dma_cfg *cfg_list,
> +                                   u32 node_size)
> +{
> +       struct sprd_dma_dev *sdev = to_sprd_dma_dev(chan);
> +       struct sprd_dma_chn_config *chn_config_list_v;
> +       struct sprd_dma_cfg start_list;
> +       int ret, i;
> +
> +       chn_config_list_v = (struct sprd_dma_chn_config *)cfg_list[0].link_cfg_v;
> +
> +       for (i = 0; i < node_size; i++) {
> +               if (cfg_list[i].link_cfg_v == 0 || cfg_list[i].link_cfg_p == 0) {
> +                       dev_err(sdev->dma_dev.dev,
> +                               "no allocated memory for list node\n");
> +                       return -EINVAL;
> +               }
> +
> +               ret = sprd_dma_config(chan, NULL, cfg_list + i,
> +                                     chn_config_list_v + i,
> +                                     LINKLIST_CONFIG);
> +               if (ret < 0) {
> +                       dev_err(sdev->dma_dev.dev,
> +                               "linklist configuration failed\n");
> +                       return ret;
> +               }
> +       }
> +
> +       memset((void *)&start_list, 0, sizeof(struct sprd_dma_cfg));
> +       start_list.link_cfg_p = cfg_list[0].link_cfg_p;
> +       start_list.irq_mode = cfg_list[0].irq_mode;
> +       start_list.src_addr = cfg_list[0].src_addr;
> +       start_list.des_addr = cfg_list[0].des_addr;
> +
> +       if (cfg_list[node_size - 1].is_end == DMA_LINK)
> +               mdesc->cycle = 1;
> +
> +       return sprd_dma_config(chan, mdesc, &start_list, NULL, SINGLE_CONFIG);
> +}
> +
> +struct dma_async_tx_descriptor *sprd_dma_prep_dma_memcpy(struct dma_chan *chan,
> +                                                        dma_addr_t dest,
> +                                                        dma_addr_t src,
> +                                                        size_t len,
> +                                                        unsigned long flags)
> +{
> +       struct sprd_dma_dev *sdev = to_sprd_dma_dev(chan);
> +       struct sprd_dma_chn *mchan = to_sprd_dma_chan(chan);
> +       struct sprd_dma_desc *mdesc = NULL;
> +       struct sprd_dma_cfg dma_cfg;
> +       u32 datawidth, src_step, des_step;
> +       int cfg_count = mchan->cfg_count;
> +       unsigned long irq_flags;
> +       int ret;
> +
> +       /*
> +        * If user did not have configuration for DMA transfer, then we should
> +        * configure the DMA controller as default configuration.
> +        */
> +       if (cfg_count == 0) {
> +               if (IS_ALIGNED(len, 4)) {
> +                       datawidth = 2;
> +                       src_step = 4;
> +                       des_step = 4;
> +               } else if (IS_ALIGNED(len, 2)) {
> +                       datawidth = 1;
> +                       src_step = 2;
> +                       des_step = 2;
> +               } else {
> +                       datawidth = 0;
> +                       src_step = 1;
> +                       des_step = 1;
> +               }
> +
> +               memset(&dma_cfg, 0, sizeof(struct sprd_dma_cfg));
> +               dma_cfg.src_addr = src;
> +               dma_cfg.des_addr = dest;
> +               dma_cfg.datawidth = datawidth;
> +               dma_cfg.src_step = src_step;
> +               dma_cfg.des_step = src_step;
> +               dma_cfg.fragmens_len = SPRD_DMA_MEMCPY_MIN_SIZE;
> +               if (len <= BLK_LEN_MASK) {
> +                       dma_cfg.block_len = len;
> +                       dma_cfg.req_mode = BLOCK_REQ_MODE;
> +                       dma_cfg.irq_mode = BLK_DONE;
> +               } else {
> +                       dma_cfg.block_len = SPRD_DMA_MEMCPY_MIN_SIZE;
> +                       dma_cfg.transcation_len = len;
> +                       dma_cfg.req_mode = TRANS_REQ_MODE;
> +                       dma_cfg.irq_mode = TRANS_DONE;
> +               }
> +               cfg_count = 1;
> +       } else if (cfg_count == 1) {
> +               memcpy(&dma_cfg, mchan->dma_cfg, sizeof(struct sprd_dma_cfg));
> +       }
> +
> +       /* get one free DMA descriptor for this DMA transfer. */
> +       spin_lock_irqsave(&mchan->chn_lock, irq_flags);
> +       if (!list_empty(&mchan->free)) {
> +               mdesc = list_first_entry(&mchan->free,
> +                                        struct sprd_dma_desc, node);
> +               list_del(&mdesc->node);
> +       }
> +       spin_unlock_irqrestore(&mchan->chn_lock, irq_flags);
> +
> +       if (!mdesc) {
> +               dev_err(sdev->dma_dev.dev, "get free descriptor failed\n");
> +               sprd_dma_process_completed(sdev);
> +               goto out;
> +       }
> +
> +       mdesc->dma_flags = flags;
> +
> +       /*
> +        * Set the DMA configuration into channel register of this DMA
> +        * descriptor. If we have multiple configuration, which means
> +        * need enable the link-list function, then we should set these
> +        * configuration into link-list address.
> +        */
> +       if (cfg_count == 1)
> +               ret = sprd_dma_config(chan, mdesc, &dma_cfg, NULL,
> +                                     SINGLE_CONFIG);
> +       else
> +               ret = sprd_dma_config_linklist(chan, mdesc, mchan->dma_cfg,
> +                                              cfg_count);
> +
> +       if (ret < 0) {
> +               spin_lock_irqsave(&mchan->chn_lock, irq_flags);
> +               list_add_tail(&mdesc->node, &mchan->free);
> +               spin_unlock_irqrestore(&mchan->chn_lock, irq_flags);
> +               dev_err(sdev->dma_dev.dev, "DMA configuration is failed\n");
> +               goto out;
> +       }
> +
> +       if (!(flags & DMA_HARDWARE_REQ))
> +               mchan->dev_id = DMA_SOFTWARE_UID;
> +
> +       /* add the free descriptor to the prepared list. */
> +       spin_lock_irqsave(&mchan->chn_lock, irq_flags);
> +       list_add_tail(&mdesc->node, &mchan->prepared);
> +       spin_unlock_irqrestore(&mchan->chn_lock, irq_flags);
> +
> +       mchan->cfg_count = 0;
> +       memset(mchan->dma_cfg, 0, sizeof(struct sprd_dma_cfg) *
> +              SPRD_DMA_CFG_COUNT);
> +       return &mdesc->desc;
> +
> +out:
> +       mchan->cfg_count = 0;
> +       memset(mchan->dma_cfg, 0, sizeof(struct sprd_dma_cfg) *
> +              SPRD_DMA_CFG_COUNT);
> +       return NULL;
> +}
> +
> +static int sprd_dma_pause(struct dma_chan *chan)
> +{
> +       struct sprd_dma_chn *mchan =
> +                       container_of(chan, struct sprd_dma_chn, chan);
> +       unsigned long flags;
> +
> +       spin_lock_irqsave(&mchan->chn_lock, flags);
> +       sprd_dma_stop(mchan);
> +       spin_unlock_irqrestore(&mchan->chn_lock, flags);
> +
> +       return 0;
> +}
> +
> +static int sprd_dma_resume(struct dma_chan *chan)
> +{
> +       struct sprd_dma_chn *mchan =
> +                       container_of(chan, struct sprd_dma_chn, chan);
> +       unsigned long flags;
> +       int ret;
> +
> +       spin_lock_irqsave(&mchan->chn_lock, flags);
> +       ret = sprd_dma_start(mchan);
> +       spin_unlock_irqrestore(&mchan->chn_lock, flags);
> +
> +       return ret;
> +}
> +
> +static int sprd_terminate_all(struct dma_chan *chan)
> +{
> +       struct sprd_dma_chn *mchan = to_sprd_dma_chan(chan);
> +       unsigned long flags;
> +
> +       spin_lock_irqsave(&mchan->chn_lock, flags);
> +       list_splice_tail_init(&mchan->prepared, &mchan->free);
> +       list_splice_tail_init(&mchan->queued, &mchan->free);
> +       list_splice_tail_init(&mchan->active, &mchan->free);
> +       list_splice_tail_init(&mchan->completed, &mchan->free);
> +
> +       sprd_dma_stop(mchan);
> +       spin_unlock_irqrestore(&mchan->chn_lock, flags);
> +
> +       return 0;
> +}
> +
> +static int sprd_dma_slave_config(struct dma_chan *chan,
> +                                struct dma_slave_config *config)
> +{
> +       struct sprd_dma_chn *mchan = to_sprd_dma_chan(chan);
> +       struct sprd_dma_cfg *sprd_cfg = container_of(config,
> +                                                    struct sprd_dma_cfg,
> +                                                    config);
> +       int i = 0;
> +
> +       do {
> +               memcpy(&mchan->dma_cfg[i], sprd_cfg, sizeof(*sprd_cfg));
> +               sprd_cfg++;
> +       } while (mchan->dma_cfg[i++].is_end == DMA_NOT_END
> +                && i < (SPRD_DMA_CFG_COUNT - 1));
> +
> +       mchan->cfg_count = i;
> +       return 0;
> +}
> +
> +static bool sprd_dma_filter_fn(struct dma_chan *chan, void *param)
> +{
> +       struct sprd_dma_chn *mchan = to_sprd_dma_chan(chan);
> +       struct of_phandle_args *dma_spec = (struct of_phandle_args *)param;
> +       unsigned int req = (unsigned int)dma_spec->args[0];
> +
> +       if (chan->device->dev->of_node == dma_spec->np)
> +               return req == (mchan->chn_num + 1);
> +       else
> +               return false;
> +}
> +
> +static struct dma_chan *sprd_dma_simple_xlate(struct of_phandle_args *dma_spec,
> +                                             struct of_dma *of_dma)
> +{
> +       struct of_dma_filter_info *info = of_dma->of_dma_data;
> +       int count = dma_spec->args_count;
> +
> +       if (!info || !info->filter_fn)
> +               return NULL;
> +
> +       if (count != 1)
> +               return NULL;
> +
> +       return dma_request_channel(info->dma_cap, info->filter_fn, dma_spec);
> +}
> +
> +static int sprd_dma_probe(struct platform_device *pdev)
> +{
> +       struct device_node *np = pdev->dev.of_node;
> +       struct sprd_dma_dev *sdev;
> +       struct sprd_dma_chn *dma_chn;
> +       struct resource *res;
> +       u32 chn_count;
> +       int ret, i;
> +
> +       if (of_property_read_u32(np, "#dma-channels", &chn_count)) {
> +               dev_err(&pdev->dev, "get dma channels count failed\n");
> +               return -ENODEV;
> +       }
> +
> +       sdev = devm_kzalloc(&pdev->dev, (sizeof(*sdev) +
> +                           (sizeof(struct sprd_dma_chn) * chn_count)),
> +                           GFP_KERNEL);
> +       if (!sdev)
> +               return -ENOMEM;
> +
> +       sdev->clk = devm_clk_get(&pdev->dev, "enable");
> +       if (IS_ERR(sdev->clk)) {
> +               dev_err(&pdev->dev, "get enable clock failed\n");
> +               return PTR_ERR(sdev->clk);
> +       }
> +
> +       /* ashb clock is optional for AGCP DMA */
> +       sdev->ashb_clk = devm_clk_get(&pdev->dev, "ashb_eb");
> +       if (IS_ERR(sdev->ashb_clk))
> +               dev_warn(&pdev->dev, "get ashb eb clock failed\n");
> +
> +       sdev->irq = platform_get_irq(pdev, 0);
> +       if (sdev->irq > 0) {
> +               ret = devm_request_irq(&pdev->dev, sdev->irq, dma_irq_handle,
> +                                      0, "sprd_dma", (void *)sdev);
> +               if (ret < 0) {
> +                       dev_err(&pdev->dev, "request dma irq failed\n");
> +                       return ret;
> +               }
> +
> +               tasklet_init(&sdev->tasklet, sprd_dma_tasklet,
> +                            (unsigned long)sdev);
> +       } else {
> +               dev_warn(&pdev->dev, "no interrupts for the DMA controller\n");
> +       }
> +
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       sdev->glb_base = devm_ioremap_nocache(&pdev->dev, res->start,
> +                                             resource_size(res));
> +       if (!sdev->glb_base)
> +               return -ENOMEM;
> +
> +       dma_cap_set(DMA_MEMCPY, sdev->dma_dev.cap_mask);
> +       sdev->total_chns = chn_count;
> +       sdev->dma_dev.chancnt = chn_count;
> +       INIT_LIST_HEAD(&sdev->dma_dev.channels);
> +       INIT_LIST_HEAD(&sdev->dma_dev.global_node);
> +       sdev->dma_dev.dev = &pdev->dev;
> +       sdev->dma_dev.device_alloc_chan_resources = sprd_dma_alloc_chan_resources;
> +       sdev->dma_dev.device_free_chan_resources = sprd_dma_free_chan_resources;
> +       sdev->dma_dev.device_tx_status = sprd_dma_tx_status;
> +       sdev->dma_dev.device_issue_pending = sprd_dma_issue_pending;
> +       sdev->dma_dev.device_prep_dma_memcpy = sprd_dma_prep_dma_memcpy;
> +       sdev->dma_dev.device_config = sprd_dma_slave_config;
> +       sdev->dma_dev.device_pause = sprd_dma_pause;
> +       sdev->dma_dev.device_resume = sprd_dma_resume;
> +       sdev->dma_dev.device_terminate_all = sprd_terminate_all;
> +
> +       for (i = 0; i < chn_count; i++) {
> +               dma_chn = &sdev->channels[i];
> +               dma_chn->chan.device = &sdev->dma_dev;
> +               dma_cookie_init(&dma_chn->chan);
> +               list_add_tail(&dma_chn->chan.device_node,
> +                             &sdev->dma_dev.channels);
> +
> +               dma_chn->chn_num = i;
> +               /* get each channel's registers base address. */
> +               dma_chn->chn_base = (void __iomem *)
> +                       ((unsigned long)sdev->glb_base +
> +                        SPRD_DMA_CHN_REG_OFFSET +
> +                        SPRD_DMA_CHN_REG_LENGTH * i);
> +
> +               spin_lock_init(&dma_chn->chn_lock);
> +               INIT_LIST_HEAD(&dma_chn->free);
> +               INIT_LIST_HEAD(&dma_chn->prepared);
> +               INIT_LIST_HEAD(&dma_chn->queued);
> +               INIT_LIST_HEAD(&dma_chn->active);
> +               INIT_LIST_HEAD(&dma_chn->completed);
> +       }
> +
> +       sdev->dma_desc_node_cachep = kmem_cache_create("dma_desc_node",
> +                                               sizeof(struct sprd_dma_desc), 0,
> +                                               SLAB_HWCACHE_ALIGN, NULL);
> +       if (!sdev->dma_desc_node_cachep) {
> +               dev_err(&pdev->dev, "allocate memory cache failed\n");
> +               return -ENOMEM;
> +       }
> +
> +       platform_set_drvdata(pdev, sdev);
> +       ret = sprd_dma_enable(sdev);
> +       if (ret)
> +               goto err_enable;
> +
> +       pm_runtime_set_active(&pdev->dev);
> +       pm_runtime_enable(&pdev->dev);
> +
> +       ret = pm_runtime_get_sync(&pdev->dev);
> +       if (ret < 0)
> +               goto err_rpm;
> +
> +       ret = dma_async_device_register(&sdev->dma_dev);
> +       if (ret < 0) {
> +               dev_err(&pdev->dev, "register dma device failed:%d\n", ret);
> +               goto err_register;
> +       }
> +
> +       sprd_dma_info.dma_cap = sdev->dma_dev.cap_mask;
> +       ret = of_dma_controller_register(np, sprd_dma_simple_xlate,
> +                                        &sprd_dma_info);
> +       if (ret) {
> +               dev_err(&pdev->dev, "failed to register of DMA controller\n");
> +               goto err_of_register;
> +       }
> +
> +       pm_runtime_put_sync(&pdev->dev);
> +       return 0;
> +
> +err_of_register:
> +       dma_async_device_unregister(&sdev->dma_dev);
> +err_register:
> +       pm_runtime_put_noidle(&pdev->dev);
> +       pm_runtime_disable(&pdev->dev);
> +err_rpm:
> +       sprd_dma_disable(sdev);
> +err_enable:
> +       kmem_cache_destroy(sdev->dma_desc_node_cachep);
> +       return ret;
> +}
> +
> +static int sprd_dma_remove(struct platform_device *pdev)
> +{
> +       struct sprd_dma_dev *sdev = platform_get_drvdata(pdev);
> +       int ret;
> +
> +       ret = pm_runtime_get_sync(&pdev->dev);
> +       if (ret < 0)
> +               return ret;
> +
> +       kmem_cache_destroy(sdev->dma_desc_node_cachep);
> +       dma_async_device_unregister(&sdev->dma_dev);
> +       sprd_dma_disable(sdev);
> +
> +       pm_runtime_put_noidle(&pdev->dev);
> +       pm_runtime_disable(&pdev->dev);
> +       return 0;
> +}
> +
> +static const struct of_device_id sprd_dma_match[] = {
> +       { .compatible = "sprd,sc9860-dma", },
> +       {},
> +};
> +
> +static int __maybe_unused sprd_dma_runtime_suspend(struct device *dev)
> +{
> +       struct sprd_dma_dev *sdev = dev_get_drvdata(dev);
> +
> +       sprd_dma_disable(sdev);
> +       return 0;
> +}
> +
> +static int __maybe_unused sprd_dma_runtime_resume(struct device *dev)
> +{
> +       struct sprd_dma_dev *sdev = dev_get_drvdata(dev);
> +
> +       return sprd_dma_enable(sdev);
> +}
> +
> +static const struct dev_pm_ops sprd_dma_pm_ops = {
> +       SET_RUNTIME_PM_OPS(sprd_dma_runtime_suspend,
> +                          sprd_dma_runtime_resume,
> +                          NULL)
> +};
> +
> +static struct platform_driver sprd_dma_driver = {
> +       .probe = sprd_dma_probe,
> +       .remove = sprd_dma_remove,
> +       .driver = {
> +               .name = "sprd-dma",
> +               .owner = THIS_MODULE,
> +               .of_match_table = sprd_dma_match,
> +               .pm = &sprd_dma_pm_ops,
> +       },
> +};
> +
> +static int __init sprd_dma_init(void)
> +{
> +       return platform_driver_register(&sprd_dma_driver);
> +}
> +arch_initcall_sync(sprd_dma_init);
> +
> +static void __exit sprd_dma_exit(void)
> +{
> +       platform_driver_unregister(&sprd_dma_driver);
> +}
> +module_exit(sprd_dma_exit);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("DMA driver for Spreadtrum");
> +MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");
> +MODULE_AUTHOR("Eric Long <eric.long@spreadtrum.com>");
> diff --git a/include/linux/dma/sprd-dma.h b/include/linux/dma/sprd-dma.h
> new file mode 100644
> index 0000000..40a8b1c
> --- /dev/null
> +++ b/include/linux/dma/sprd-dma.h
> @@ -0,0 +1,270 @@
> +/*
> + * Copyright (C) 2017 Spreadtrum Communications Inc.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that 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.
> + */
> +
> +#ifndef __SPRD_DMA_H
> +#define __SPRD_DMA_H
> +#include <linux/dmaengine.h>
> +
> +/* DMA request ID definition */
> +#define DMA_SOFTWARE_UID       0
> +#define DMA_SIM_RX             1
> +#define DMA_SIM_TX             2
> +#define DMA_IIS0_RX            3
> +#define DMA_IIS0_TX            4
> +#define DMA_IIS1_RX            5
> +#define DMA_IIS1_TX            6
> +#define DMA_IIS2_RX            7
> +#define DMA_IIS2_TX            8
> +#define DMA_IIS3_RX            9
> +#define DMA_IIS3_TX            10
> +#define DMA_SPI0_RX            11
> +#define DMA_SPI0_TX            12
> +#define DMA_SPI1_RX            13
> +#define DMA_SPI1_TX            14
> +#define DMA_SPI2_RX            15
> +#define DMA_SPI2_TX            16
> +#define DMA_UART0_RX           17
> +#define DMA_UART0_TX           18
> +#define DMA_UART1_RX           19
> +#define DMA_UART1_TX           20
> +#define DMA_UART2_RX           21
> +#define DMA_UART2_TX           22
> +#define DMA_UART3_RX           23
> +#define DMA_UART3_TX           24
> +#define DMA_UART4_RX           25
> +#define DMA_UART4_TX           26
> +#define DMA_DRM_CPT            27
> +#define DMA_DRM_RAW            28
> +#define DMA_VB_DA0             29
> +#define DMA_VB_DA1             30
> +#define DMA_VB_AD0             31
> +#define DMA_VB_AD1             32
> +#define DMA_VB_AD2             33
> +#define DMA_VB_AD3             34
> +#define DMA_GPS                        35
> +#define DMA_SDIO0_RD           36
> +#define DMA_SDIO0_WR           37
> +#define DMA_SDIO1_RD           38
> +#define DMA_SDIO1_WR           39
> +#define DMA_SDIO2_RD           40
> +#define DMA_SDIO2_WR           41
> +#define DMA_EMMC_RD            42
> +#define DMA_EMMC_WR            43
> +
> +/*
> + * enum dma_datawidth: define the DMA transfer data width
> + * @BYTE_WIDTH: 1 byte width
> + * @SHORT_WIDTH: 2 bytes width
> + * @WORD_WIDTH: 4 bytes width
> + * @DWORD_WIDTH: 8 bytes width
> + */
> +enum dma_datawidth {
> +       BYTE_WIDTH,
> +       SHORT_WIDTH,
> +       WORD_WIDTH,
> +       DWORD_WIDTH,
> +};
> +
> +/*
> + * enum dma_request_mode: define the DMA request mode
> + * @FRAG_REQ_MODE: fragment request mode
> + * @BLOCK_REQ_MODE: block request mode
> + * @TRANS_REQ_MODE: transaction request mode
> + * @LIST_REQ_MODE: link-list request mode
> + *
> + * We have 4 types request mode: fragment mode, block mode, transaction mode
> + * and linklist mode. One transaction can contain several blocks, one block can
> + * contain several fragments. Link-list mode means we can save several DMA
> + * configuration into one reserved memory, then DMA can fetch each DMA
> + * configuration automatically to start transfer.
> + */
> +enum dma_request_mode {
> +       FRAG_REQ_MODE,
> +       BLOCK_REQ_MODE,
> +       TRANS_REQ_MODE,
> +       LIST_REQ_MODE,
> +};
> +
> +/*
> + * enum dma_int_type: define the DMA interrupt type
> + * @NO_INT: do not need generate DMA interrupt.
> + * @FRAG_DONE: fragment done interrupt when one fragment request is done.
> + * @BLK_DONE: block done interrupt when one block request is done.
> + * @TRANS_DONE: tansaction done interrupt when one transaction request is done.
> + * @LIST_DONE: link-list done interrupt when one link-list request is done.
> + * @CONFIG_ERR: configure error interrupt when configuration is incorrect
> + * @BLOCK_FRAG_DONE: block and fragment interrupt when one fragment or block
> + * request is done.
> + * @TRANS_FRAG_DONE: transaction and fragment interrupt when one transaction
> + * request or fragment request is done.
> + * @TRANS_BLOCK_DONE: transaction and block interrupt when one transaction
> + * request or block request is done.
> + */
> +enum dma_int_type {
> +       NO_INT,
> +       FRAG_DONE,
> +       BLK_DONE,
> +       TRANS_DONE,
> +       LIST_DONE,
> +       CONFIG_ERR,
> +       BLOCK_FRAG_DONE,
> +       TRANS_FRAG_DONE,
> +       TRANS_BLOCK_DONE,
> +};
> +
> +/*
> + * enum dma_pri_level: define the DMA channel priority level
> + * @DMA_PRI_0: level 0
> + * @DMA_PRI_1: level 1
> + * @DMA_PRI_2: level 2
> + * @DMA_PRI_3: level 3
> + *
> + * When there are several DMA channels need to start, the DMA controller's
> + * arbitration will choose the high priority channel to start firstly.
> + */
> +enum dma_pri_level {
> +       DMA_PRI_0,
> +       DMA_PRI_1,
> +       DMA_PRI_2,
> +       DMA_PRI_3,
> +};
> +
> +/*
> + * enum dma_switch_mode: define the DMA transfer format
> + * @DATA_ABCD: ABCD to ABCD
> + * @DATA_DCBA: ABCD to DCBA
> + * @DATA_BADC: ABCD to BADC
> + * @DATA_CDAB: ABCD to CDAB
> + */
> +enum dma_switch_mode {
> +       DATA_ABCD,
> +       DATA_DCBA,
> +       DATA_BADC,
> +       DATA_CDAB,
> +};
> +
> +/*
> + * enum dma_end_type: define the DMA configuration end type
> + * @DMA_NOT_END: DMA configuration is not end
> + * @DMA_END: DMA configuration is end but not one link-list cycle configuration
> + * @DMA_LINK: DMA configuration is end but it is one link-list cycle
> + * configuration
> + *
> + * Since DMA contrller can support link-list transfer mode, that means user can
> + * supply several DMA configuration and each configuration can be pointed by
> + * previous link pointer register, then DMA controller will start to transfer
> + * for each DMA configuration automatically. DMA_END and DMA_LINK flag can
> + * indicate these several configuration is end, but DMA_LINK can also indicate
> + * these listed configuration is one cycle. For example if we have 4 group DMA
> + * configuration and we set DMA_LINK, which means it will start to transfer from
> + * cfg0--->cfg1--->cfg2--->cfg3, then back to cfg0 as one cycle.
> + */
> +enum dma_end_type {
> +       DMA_NOT_END,
> +       DMA_END,
> +       DMA_LINK,
> +};
> +
> +/*
> + * enum dma_flags: define the DMA flags
> + * @DMA_HARDWARE_REQ: hardware request channel to start transfer by hardware id.
> + * @DMA_SOFTWARE_REQ: software request channel to start transfer.
> + * @DMA_GROUP1_SRC: indicate this is source channel of group 1 which can be
> + * start another channel.
> + * @DMA_GROUP1_DST: indicate this is destination channel of group 1 which will
> + * be started by source channel.
> + * @DMA_GROUP2_SRC: indicate this is source channel of group 2 which can be
> + * start another channel.
> + * @DMA_GROUP2_DST: indicate this is destination channel of group 2 which will
> + * be started by source channel.
> + * @DMA_MUTL_FRAG_DONE: when fragment is done of source channel which will
> + * start another destination channel.
> + * @DMA_MUTL_BLK_DONE: when block is done of source channel which will start
> + * another destination channel.
> + * @DMA_MUTL_TRANS_DONE: when transaction is done of source channel which will
> + * start another destination channel.
> + * @DMA_MUTL_LIST_DONE: when link-list is done of source channel which will
> + * start another destination channel.
> + *
> + * Since DMA controller can support 2 stage transfer which means when one
> + * channel transfer is done, then it can start another channel's transfer
> + * automatically by interrupt type.
> + */
> +enum dma_flags {
> +       DMA_HARDWARE_REQ = BIT(0),
> +       DMA_SOFTWARE_REQ = BIT(1),
> +       DMA_GROUP1_SRC = BIT(2),
> +       DMA_GROUP1_DST = BIT(3),
> +       DMA_GROUP2_SRC = BIT(4),
> +       DMA_GROUP2_DST = BIT(5),
> +       DMA_MUTL_FRAG_DONE = BIT(6),
> +       DMA_MUTL_BLK_DONE = BIT(7),
> +       DMA_MUTL_TRANS_DONE = BIT(8),
> +       DMA_MUTL_LIST_DONE = BIT(9),
> +};
> +
> +/*
> + * struct sprd_dma_cfg: DMA configuration for users
> + * @config: salve config structure
> + * @chn_pri: the channel priority
> + * @datawidth: the data width
> + * @req_mode: the request mode
> + * @irq_mode: the interrupt mode
> + * @swt_mode: the switch mode
> + * @link_cfg_v: point to the virtual memory address to save link-list DMA
> + * configuration
> + * @link_cfg_p: point to the physical memory address to save link-list DMA
> + * configuration
> + * @src_addr: the source address
> + * @des_addr: the destination address
> + * @fragmens_len: one fragment request length
> + * @block_len; one block request length
> + * @transcation_len: one transaction request length
> + * @src_step: source side transfer step
> + * @des_step: destination side transfer step
> + * @src_frag_step: source fragment transfer step
> + * @dst_frag_step: destination fragment transfer step
> + * @src_blk_step: source block transfer step
> + * @dst_blk_step: destination block transfer step
> + * @wrap_ptr: wrap jump pointer address
> + * @wrap_to: wrap jump to address
> + * @dev_id: hardware device id to start DMA transfer
> + * @is_end: DMA configuration end type
> + */
> +struct sprd_dma_cfg {
> +       struct dma_slave_config config;
> +       enum dma_pri_level chn_pri;
> +       enum dma_datawidth datawidth;
> +       enum dma_request_mode req_mode;
> +       enum dma_int_type irq_mode;
> +       enum dma_switch_mode swt_mode;
> +       unsigned long link_cfg_v;
> +       unsigned long link_cfg_p;
> +       unsigned long src_addr;
> +       unsigned long des_addr;
> +       u32 fragmens_len;
> +       u32 block_len;
> +       u32 transcation_len;
> +       u32 src_step;
> +       u32 des_step;
> +       u32 src_frag_step;
> +       u32 dst_frag_step;
> +       u32 src_blk_step;
> +       u32 dst_blk_step;
> +       u32 wrap_ptr;
> +       u32 wrap_to;
> +       u32 dev_id;
> +       enum dma_end_type is_end;
> +};
> +
> +#endif
> --
> 1.7.9.5
>
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Hi Chunyan,

On 21 July 2017 at 10:50, Chunyan Zhang <zhang.lyra@gmail.com> wrote:
> Hi Baolin,
>
> On 18 July 2017 at 15:06, Baolin Wang <baolin.wang@spreadtrum.com> wrote:
>> This patch adds the DMA controller driver for Spreadtrum SC9860 platform.
>
> I guess this driver is not only for SC9860, instead it should work for
> all most all Spreadtrum's platforms?

No, now this driver is only for SC9860 platform. If we make this
driver work on other Spreadtrum platform, we should submit new patches
with modifing DT binding files and compatible string.

>
>>
>> Signed-off-by: Baolin Wang <baolin.wang@spreadtrum.com>
>> ---
>>  drivers/dma/Kconfig          |    7 +
>>  drivers/dma/Makefile         |    1 +
>>  drivers/dma/sprd-dma.c       | 1451 ++++++++++++++++++++++++++++++++++++++++++
>>  include/linux/dma/sprd-dma.h |  270 ++++++++
>>  4 files changed, 1729 insertions(+)
>>  create mode 100644 drivers/dma/sprd-dma.c
>>  create mode 100644 include/linux/dma/sprd-dma.h
>>
>> diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
>> index fa8f9c0..961f6ea 100644
>> --- a/drivers/dma/Kconfig
>> +++ b/drivers/dma/Kconfig
>> @@ -477,6 +477,13 @@ config STM32_DMA
>>           If you have a board based on such a MCU and wish to use DMA say Y
>>           here.
>>
>> +config SPRD_DMA
>> +       bool "Spreadtrum DMA support"
>> +       depends on ARCH_SPRD
>> +       select DMA_ENGINE
>> +       help
>> +         Enable support for the on-chip DMA controller on Spreadtrum platform.
>> +
>>  config S3C24XX_DMAC
>>         bool "Samsung S3C24XX DMA support"
>>         depends on ARCH_S3C24XX || COMPILE_TEST
>> diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
>> index d12ab29..0fee561 100644
>> --- a/drivers/dma/Makefile
>> +++ b/drivers/dma/Makefile
>> @@ -58,6 +58,7 @@ obj-$(CONFIG_RENESAS_DMA) += sh/
>>  obj-$(CONFIG_SIRF_DMA) += sirf-dma.o
>>  obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o
>>  obj-$(CONFIG_STM32_DMA) += stm32-dma.o
>> +obj-$(CONFIG_SPRD_DMA) += sprd-dma.o
>>  obj-$(CONFIG_S3C24XX_DMAC) += s3c24xx-dma.o
>>  obj-$(CONFIG_TXX9_DMAC) += txx9dmac.o
>>  obj-$(CONFIG_TEGRA20_APB_DMA) += tegra20-apb-dma.o
>> diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
>> new file mode 100644
>> index 0000000..64eaef7
>> --- /dev/null
>> +++ b/drivers/dma/sprd-dma.c
>> @@ -0,0 +1,1451 @@
>> +/*
>> + * Copyright (C) 2017 Spreadtrum Communications Inc.
>> + *
>> + * This software is licensed under the terms of the GNU General Public
>> + * License version 2, as published by the Free Software Foundation, and
>> + * may be copied, distributed, and modified under those terms.
>> + *
>> + * This program is distributed in the hope that 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.
>> + */
>> +
>
> In order to keep consistent with other Spreadtrum's drivers/ DT files
> that had been upstreamed, I suggest to use SPDX-License-Identifier
> tag.

Since I saw other new drivers still use this license and I am not sure
we must change to SPDX-License-Identifier tag. But it is fine for me
to change the license tag.

On Tue, Jul 18, 2017 at 03:06:12PM +0800, Baolin Wang wrote:

> +/* DMA global registers definition */
> +#define DMA_GLB_PAUSE			0x0
> +#define DMA_GLB_FRAG_WAIT		0x4
> +#define DMA_GLB_REQ_PEND0_EN		0x8
> +#define DMA_GLB_REQ_PEND1_EN		0xc
> +#define DMA_GLB_INT_RAW_STS		0x10
> +#define DMA_GLB_INT_MSK_STS		0x14
> +#define DMA_GLB_REQ_STS			0x18
> +#define DMA_GLB_CHN_EN_STS		0x1c
> +#define DMA_GLB_DEBUG_STS		0x20
> +#define DMA_GLB_ARB_SEL_STS		0x24
> +#define DMA_GLB_CHN_START_CHN_CFG1	0x28
> +#define DMA_GLB_CHN_START_CHN_CFG2	0x2c
> +#define DMA_CHN_LLIST_OFFSET		0x10
> +#define DMA_GLB_REQ_CID(base, uid)	\
> +		((unsigned long)(base) + 0x2000 + 0x4 * ((uid) - 1))

why do you need a cast here...

> +/* DMA_CHN_INTC register definition */
> +#define DMA_CHN_INT_MASK		GENMASK(4, 0)
> +#define DMA_CHN_INT_CLR_OFFSET		24

Why cant this be expressed in GENMASK?

> +/* DMA_CHN_CFG register definition */
> +#define DMA_CHN_EN			BIT(0)
> +#define DMA_CHN_PRIORITY_OFFSET		12
> +#define LLIST_EN_OFFSET			4
> +#define CHN_WAIT_BDONE			24
> +#define DMA_DONOT_WAIT_BDONE		1

All these too...

> +static void sprd_dma_set_uid(struct sprd_dma_chn *mchan)
> +{
> +	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&mchan->chan);
> +	u32 dev_id = mchan->dev_id;
> +
> +	if (dev_id != DMA_SOFTWARE_UID)

Whats a UID?

> +		writel(mchan->chn_num + 1, (void __iomem *)DMA_GLB_REQ_CID(
> +		       sdev->glb_base, dev_id));

And again the cast, I dont think we need casts like this...

> +static void sprd_dma_clear_int(struct sprd_dma_chn *mchan)
> +{
> +	u32 intc = readl(mchan->chn_base + DMA_CHN_INTC);
> +
> +	intc |= DMA_CHN_INT_MASK << DMA_CHN_INT_CLR_OFFSET;
> +	writel(intc, mchan->chn_base + DMA_CHN_INTC);

How about adding a updatel macro and use that here and few other places.

> +static void sprd_dma_stop_and_disable(struct sprd_dma_chn *mchan)
> +{
> +	u32 cfg = readl(mchan->chn_base + DMA_CHN_CFG);
> +	u32 pause, timeout = DMA_CHN_PAUSE_CNT;
> +
> +	if (!(cfg & DMA_CHN_EN))
> +		return;
> +
> +	pause = readl(mchan->chn_base + DMA_CHN_PAUSE);
> +	pause |= DMA_CHN_PAUSE_EN;
> +	writel(pause, mchan->chn_base + DMA_CHN_PAUSE);
> +
> +	do {
> +		pause = readl(mchan->chn_base + DMA_CHN_PAUSE);
> +		if (pause & DMA_CHN_PAUSE_STS)
> +			break;
> +
> +		cpu_relax();
> +	} while (--timeout > 0);

We should check here if timeout occured and at least log the error

> +static enum dma_int_type sprd_dma_get_int_type(struct sprd_dma_chn *mchan)
> +{
> +	u32 intc_reg = readl(mchan->chn_base + DMA_CHN_INTC);
> +
> +	if (intc_reg & CFGERR_INT_STS)
> +		return CONFIG_ERR;
> +	else if (intc_reg & LLIST_INT_STS)
> +		return LIST_DONE;
> +	else if (intc_reg & TRSC_INT_STS)
> +		return TRANS_DONE;
> +	else if (intc_reg & BLK_INT_STS)
> +		return BLK_DONE;
> +	else if (intc_reg & FRAG_INT_STS)
> +		return FRAG_DONE;

this seems a good case for using switch-cases

> +static int sprd_dma_chn_start_chn(struct sprd_dma_chn *mchan,
> +				  struct sprd_dma_desc *mdesc)
> +{
> +	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&mchan->chan);
> +	enum dma_flags flag = mdesc->dma_flags;
> +	int chn = mchan->chn_num + 1;
> +	unsigned int cfg_group1, cfg_group2, start_mode = 0;
> +
> +	if (!(flag & (DMA_GROUP1_SRC | DMA_GROUP2_SRC | DMA_GROUP1_DST |
> +		      DMA_GROUP2_DST)))
> +		return 0;
> +
> +	if (flag & (DMA_GROUP1_SRC | DMA_GROUP2_SRC)) {
> +		switch (flag & (DMA_MUTL_FRAG_DONE | DMA_MUTL_BLK_DONE |
> +			DMA_MUTL_TRANS_DONE | DMA_MUTL_LIST_DONE)) {
> +		case DMA_MUTL_FRAG_DONE:
> +			start_mode = 0;
> +			break;

empty line after each break helps with readability

> +/*
> + * struct sprd_dma_cfg: DMA configuration for users
> + * @config: salve config structure

typo

> + * @chn_pri: the channel priority
> + * @datawidth: the data width
> + * @req_mode: the request mode
> + * @irq_mode: the interrupt mode
> + * @swt_mode: the switch mode
> + * @link_cfg_v: point to the virtual memory address to save link-list DMA
> + * configuration
> + * @link_cfg_p: point to the physical memory address to save link-list DMA
> + * configuration
> + * @src_addr: the source address
> + * @des_addr: the destination address
> + * @fragmens_len: one fragment request length
> + * @block_len; one block request length
> + * @transcation_len: one transaction request length
> + * @src_step: source side transfer step
> + * @des_step: destination side transfer step
> + * @src_frag_step: source fragment transfer step
> + * @dst_frag_step: destination fragment transfer step
> + * @src_blk_step: source block transfer step
> + * @dst_blk_step: destination block transfer step
> + * @wrap_ptr: wrap jump pointer address
> + * @wrap_to: wrap jump to address
> + * @dev_id: hardware device id to start DMA transfer
> + * @is_end: DMA configuration end type
> + */
> +struct sprd_dma_cfg {
> +	struct dma_slave_config config;
> +	enum dma_pri_level chn_pri;
> +	enum dma_datawidth datawidth;

why not use src/dst_addr_width

> +	enum dma_request_mode req_mode;
> +	enum dma_int_type irq_mode;
> +	enum dma_switch_mode swt_mode;

what do these modes mean?

> +	unsigned long link_cfg_v;
> +	unsigned long link_cfg_p;

why should clients know and send this, seems internal to dma

> +	unsigned long src_addr;
> +	unsigned long des_addr;

whats wrong with src/dst_addr

> +	u32 fragmens_len;
> +	u32 block_len;

oh please, I think I will stop here now :(

> +	u32 transcation_len;
> +	u32 src_step;
> +	u32 des_step;
> +	u32 src_frag_step;
> +	u32 dst_frag_step;
> +	u32 src_blk_step;
> +	u32 dst_blk_step;
> +	u32 wrap_ptr;
> +	u32 wrap_to;
> +	u32 dev_id;
> +	enum dma_end_type is_end;

Looking at this I think these are overkill, many of them can be handled
properly by current dmaengine interfaces, so please use those before you
invent your own...

Also the code is bloated because you don't use virt-dma, pls use that. I
skipped many parts of the driver as I feel driver needs more work.

Hi,

On 六,  7月 22, 2017 at 01:27:31下午 +0530, Vinod Koul wrote:
> On Tue, Jul 18, 2017 at 03:06:12PM +0800, Baolin Wang wrote:
> 
> > +/* DMA global registers definition */
> > +#define DMA_GLB_PAUSE			0x0
> > +#define DMA_GLB_FRAG_WAIT		0x4
> > +#define DMA_GLB_REQ_PEND0_EN		0x8
> > +#define DMA_GLB_REQ_PEND1_EN		0xc
> > +#define DMA_GLB_INT_RAW_STS		0x10
> > +#define DMA_GLB_INT_MSK_STS		0x14
> > +#define DMA_GLB_REQ_STS			0x18
> > +#define DMA_GLB_CHN_EN_STS		0x1c
> > +#define DMA_GLB_DEBUG_STS		0x20
> > +#define DMA_GLB_ARB_SEL_STS		0x24
> > +#define DMA_GLB_CHN_START_CHN_CFG1	0x28
> > +#define DMA_GLB_CHN_START_CHN_CFG2	0x2c
> > +#define DMA_CHN_LLIST_OFFSET		0x10
> > +#define DMA_GLB_REQ_CID(base, uid)	\
> > +		((unsigned long)(base) + 0x2000 + 0x4 * ((uid) - 1))
> 
> why do you need a cast here...

Since the UID registers address is calculated by the UID number. But
I can remove the cast and define the UID global macros.

> 
> > +/* DMA_CHN_INTC register definition */
> > +#define DMA_CHN_INT_MASK		GENMASK(4, 0)
> > +#define DMA_CHN_INT_CLR_OFFSET		24
> 
> Why cant this be expressed in GENMASK?

Since this is not one mask, it is one offset. If we use GENMASK(4, 3)
instead of magic number 24, it is not very clear for the offset bit.

> 
> > +/* DMA_CHN_CFG register definition */
> > +#define DMA_CHN_EN			BIT(0)
> > +#define DMA_CHN_PRIORITY_OFFSET		12
> > +#define LLIST_EN_OFFSET			4
> > +#define CHN_WAIT_BDONE			24
> > +#define DMA_DONOT_WAIT_BDONE		1
> 
> All these too...
> 
> > +static void sprd_dma_set_uid(struct sprd_dma_chn *mchan)
> > +{
> > +	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&mchan->chan);
> > +	u32 dev_id = mchan->dev_id;
> > +
> > +	if (dev_id != DMA_SOFTWARE_UID)
> 
> Whats a UID?

It is for users, every user was assigned one unique hardware ID.
Then the user can trigger the DMA to transfer by the user ID.

> 
> > +		writel(mchan->chn_num + 1, (void __iomem *)DMA_GLB_REQ_CID(
> > +		       sdev->glb_base, dev_id));
> 
> And again the cast, I dont think we need casts like this...

OK.

> 
> > +static void sprd_dma_clear_int(struct sprd_dma_chn *mchan)
> > +{
> > +	u32 intc = readl(mchan->chn_base + DMA_CHN_INTC);
> > +
> > +	intc |= DMA_CHN_INT_MASK << DMA_CHN_INT_CLR_OFFSET;
> > +	writel(intc, mchan->chn_base + DMA_CHN_INTC);
> 
> How about adding a updatel macro and use that here and few other places.

OK.

> 
> > +static void sprd_dma_stop_and_disable(struct sprd_dma_chn *mchan)
> > +{
> > +	u32 cfg = readl(mchan->chn_base + DMA_CHN_CFG);
> > +	u32 pause, timeout = DMA_CHN_PAUSE_CNT;
> > +
> > +	if (!(cfg & DMA_CHN_EN))
> > +		return;
> > +
> > +	pause = readl(mchan->chn_base + DMA_CHN_PAUSE);
> > +	pause |= DMA_CHN_PAUSE_EN;
> > +	writel(pause, mchan->chn_base + DMA_CHN_PAUSE);
> > +
> > +	do {
> > +		pause = readl(mchan->chn_base + DMA_CHN_PAUSE);
> > +		if (pause & DMA_CHN_PAUSE_STS)
> > +			break;
> > +
> > +		cpu_relax();
> > +	} while (--timeout > 0);
> 
> We should check here if timeout occured and at least log the error

Yes, will add one warning meesage.

> 
> > +static enum dma_int_type sprd_dma_get_int_type(struct sprd_dma_chn *mchan)
> > +{
> > +	u32 intc_reg = readl(mchan->chn_base + DMA_CHN_INTC);
> > +
> > +	if (intc_reg & CFGERR_INT_STS)
> > +		return CONFIG_ERR;
> > +	else if (intc_reg & LLIST_INT_STS)
> > +		return LIST_DONE;
> > +	else if (intc_reg & TRSC_INT_STS)
> > +		return TRANS_DONE;
> > +	else if (intc_reg & BLK_INT_STS)
> > +		return BLK_DONE;
> > +	else if (intc_reg & FRAG_INT_STS)
> > +		return FRAG_DONE;
> 
> this seems a good case for using switch-cases

OK.

> 
> > +static int sprd_dma_chn_start_chn(struct sprd_dma_chn *mchan,
> > +				  struct sprd_dma_desc *mdesc)
> > +{
> > +	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&mchan->chan);
> > +	enum dma_flags flag = mdesc->dma_flags;
> > +	int chn = mchan->chn_num + 1;
> > +	unsigned int cfg_group1, cfg_group2, start_mode = 0;
> > +
> > +	if (!(flag & (DMA_GROUP1_SRC | DMA_GROUP2_SRC | DMA_GROUP1_DST |
> > +		      DMA_GROUP2_DST)))
> > +		return 0;
> > +
> > +	if (flag & (DMA_GROUP1_SRC | DMA_GROUP2_SRC)) {
> > +		switch (flag & (DMA_MUTL_FRAG_DONE | DMA_MUTL_BLK_DONE |
> > +			DMA_MUTL_TRANS_DONE | DMA_MUTL_LIST_DONE)) {
> > +		case DMA_MUTL_FRAG_DONE:
> > +			start_mode = 0;
> > +			break;
> 
> empty line after each break helps with readability

OK.

> 
> > +/*
> > + * struct sprd_dma_cfg: DMA configuration for users
> > + * @config: salve config structure
> 
> typo

Sorry, will fix it.

> 
> > + * @chn_pri: the channel priority
> > + * @datawidth: the data width
> > + * @req_mode: the request mode
> > + * @irq_mode: the interrupt mode
> > + * @swt_mode: the switch mode
> > + * @link_cfg_v: point to the virtual memory address to save link-list DMA
> > + * configuration
> > + * @link_cfg_p: point to the physical memory address to save link-list DMA
> > + * configuration
> > + * @src_addr: the source address
> > + * @des_addr: the destination address
> > + * @fragmens_len: one fragment request length
> > + * @block_len; one block request length
> > + * @transcation_len: one transaction request length
> > + * @src_step: source side transfer step
> > + * @des_step: destination side transfer step
> > + * @src_frag_step: source fragment transfer step
> > + * @dst_frag_step: destination fragment transfer step
> > + * @src_blk_step: source block transfer step
> > + * @dst_blk_step: destination block transfer step
> > + * @wrap_ptr: wrap jump pointer address
> > + * @wrap_to: wrap jump to address
> > + * @dev_id: hardware device id to start DMA transfer
> > + * @is_end: DMA configuration end type
> > + */
> > +struct sprd_dma_cfg {
> > +	struct dma_slave_config config;
> > +	enum dma_pri_level chn_pri;
> > +	enum dma_datawidth datawidth;
> 
> why not use src/dst_addr_width

OK.

> 
> > +	enum dma_request_mode req_mode;
> > +	enum dma_int_type irq_mode;
> > +	enum dma_switch_mode swt_mode;
> 
> what do these modes mean?

I explained these structure where defining these modes.

> 
> > +	unsigned long link_cfg_v;
> > +	unsigned long link_cfg_p;
> 
> why should clients know and send this, seems internal to dma

Since there are some special cases for our DMA. This driver can
cover several DMA controllers, but for some special cases one
DMA controller just can access the memories which specified
by the user. Anyway will fix this issue in next version.

> 
> > +	unsigned long src_addr;
> > +	unsigned long des_addr;
> 
> whats wrong with src/dst_addr

Will fix this.

> 
> > +	u32 fragmens_len;
> > +	u32 block_len;
> 
> oh please, I think I will stop here now :(
> 
> > +	u32 transcation_len;
> > +	u32 src_step;
> > +	u32 des_step;
> > +	u32 src_frag_step;
> > +	u32 dst_frag_step;
> > +	u32 src_blk_step;
> > +	u32 dst_blk_step;
> > +	u32 wrap_ptr;
> > +	u32 wrap_to;
> > +	u32 dev_id;
> > +	enum dma_end_type is_end;
> 
> Looking at this I think these are overkill, many of them can be handled
> properly by current dmaengine interfaces, so please use those before you
> invent your own...
> 
> Also the code is bloated because you don't use virt-dma, pls use that. I
> skipped many parts of the driver as I feel driver needs more work.

OK. I will check the virt-dma. Thanks for your commnets.

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On Tue, Jul 18, 2017 at 03:06:11PM +0800, Baolin Wang wrote:
> This patch adds the binding documentation for Spreadtrum SC9860 DMA
> controller device.
> 
> Signed-off-by: Baolin Wang <baolin.wang@spreadtrum.com>
> ---
>  Documentation/devicetree/bindings/dma/sprd-dma.txt |   41 ++++++++++++++++++++
>  1 file changed, 41 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/dma/sprd-dma.txt
> 
> diff --git a/Documentation/devicetree/bindings/dma/sprd-dma.txt b/Documentation/devicetree/bindings/dma/sprd-dma.txt
> new file mode 100644
> index 0000000..3ccf776
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/sprd-dma.txt
> @@ -0,0 +1,41 @@
> +* Spreadtrum DMA controller
> +
> +This driver follows the generic DMA bindings defined in dma.txt.

s/driver/binding/

With that,

Acked-by: Rob Herring <robh@kernel.org>
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On Mon, Jul 24, 2017 at 02:46:00PM +0800, Baolin Wang wrote:
> Hi,
> 
> On 六,  7月 22, 2017 at 01:27:31下午 +0530, Vinod Koul wrote:
> > On Tue, Jul 18, 2017 at 03:06:12PM +0800, Baolin Wang wrote:

> > > +static void sprd_dma_set_uid(struct sprd_dma_chn *mchan)
> > > +{
> > > +	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&mchan->chan);
> > > +	u32 dev_id = mchan->dev_id;
> > > +
> > > +	if (dev_id != DMA_SOFTWARE_UID)
> > 
> > Whats a UID?
> 
> It is for users, every user was assigned one unique hardware ID.
> Then the user can trigger the DMA to transfer by the user ID.

sounds like a slave id to me (hint read again struct dma_slave_config)

> > > +	u32 fragmens_len;
> > > +	u32 block_len;
> > 
> > oh please, I think I will stop here now :(
> > 
> > > +	u32 transcation_len;
> > > +	u32 src_step;
> > > +	u32 des_step;
> > > +	u32 src_frag_step;
> > > +	u32 dst_frag_step;
> > > +	u32 src_blk_step;
> > > +	u32 dst_blk_step;
> > > +	u32 wrap_ptr;
> > > +	u32 wrap_to;
> > > +	u32 dev_id;
> > > +	enum dma_end_type is_end;
> > 
> > Looking at this I think these are overkill, many of them can be handled
> > properly by current dmaengine interfaces, so please use those before you
> > invent your own...
> > 
> > Also the code is bloated because you don't use virt-dma, pls use that. I
> > skipped many parts of the driver as I feel driver needs more work.
> 
> OK. I will check the virt-dma. Thanks for your commnets.

Ok, but the bigger concern is that people have defined generic interfaces
for everyone to use, so you should also use them, the hw doesn't seem
anything special which cannot be accommodated in the current fwk, if not do
tell me which parts don't fit before you invent your own interfaces...

On 25 July 2017 at 01:52, Rob Herring <robh@kernel.org> wrote:
> On Tue, Jul 18, 2017 at 03:06:11PM +0800, Baolin Wang wrote:
>> This patch adds the binding documentation for Spreadtrum SC9860 DMA
>> controller device.
>>
>> Signed-off-by: Baolin Wang <baolin.wang@spreadtrum.com>
>> ---
>>  Documentation/devicetree/bindings/dma/sprd-dma.txt |   41 ++++++++++++++++++++
>>  1 file changed, 41 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/dma/sprd-dma.txt
>>
>> diff --git a/Documentation/devicetree/bindings/dma/sprd-dma.txt b/Documentation/devicetree/bindings/dma/sprd-dma.txt
>> new file mode 100644
>> index 0000000..3ccf776
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/dma/sprd-dma.txt
>> @@ -0,0 +1,41 @@
>> +* Spreadtrum DMA controller
>> +
>> +This driver follows the generic DMA bindings defined in dma.txt.
>
> s/driver/binding/
>
> With that,
>
> Acked-by: Rob Herring <robh@kernel.org>

Will fix this in next version. Thanks Rob.

Hi,

On 25 July 2017 at 11:38, Vinod Koul <vinod.koul@intel.com> wrote:
> On Mon, Jul 24, 2017 at 02:46:00PM +0800, Baolin Wang wrote:
>> Hi,
>>
>> On 六,  7月 22, 2017 at 01:27:31下午 +0530, Vinod Koul wrote:
>> > On Tue, Jul 18, 2017 at 03:06:12PM +0800, Baolin Wang wrote:
>
>> > > +static void sprd_dma_set_uid(struct sprd_dma_chn *mchan)
>> > > +{
>> > > + struct sprd_dma_dev *sdev = to_sprd_dma_dev(&mchan->chan);
>> > > + u32 dev_id = mchan->dev_id;
>> > > +
>> > > + if (dev_id != DMA_SOFTWARE_UID)
>> >
>> > Whats a UID?
>>
>> It is for users, every user was assigned one unique hardware ID.
>> Then the user can trigger the DMA to transfer by the user ID.
>
> sounds like a slave id to me (hint read again struct dma_slave_config)

Yes.

>
>> > > + u32 fragmens_len;
>> > > + u32 block_len;
>> >
>> > oh please, I think I will stop here now :(
>> >
>> > > + u32 transcation_len;
>> > > + u32 src_step;
>> > > + u32 des_step;
>> > > + u32 src_frag_step;
>> > > + u32 dst_frag_step;
>> > > + u32 src_blk_step;
>> > > + u32 dst_blk_step;
>> > > + u32 wrap_ptr;
>> > > + u32 wrap_to;
>> > > + u32 dev_id;
>> > > + enum dma_end_type is_end;
>> >
>> > Looking at this I think these are overkill, many of them can be handled
>> > properly by current dmaengine interfaces, so please use those before you
>> > invent your own...
>> >
>> > Also the code is bloated because you don't use virt-dma, pls use that. I
>> > skipped many parts of the driver as I feel driver needs more work.
>>
>> OK. I will check the virt-dma. Thanks for your commnets.
>
> Ok, but the bigger concern is that people have defined generic interfaces
> for everyone to use, so you should also use them, the hw doesn't seem
> anything special which cannot be accommodated in the current fwk, if not do
> tell me which parts don't fit before you invent your own interfaces...

OK. I think I missed something and I will check the generic interfaces
again. Thanks for your help.