From: Eric Long <eric.l...@spreadtrum.com>

This patch adds the 'device_config' and 'device_prep_slave_sg' interfaces
for users to configure DMA, as well as adding one 'struct sprd_dma_config'
structure to save Spreadtrum DMA configuration for each DMA channel.

Signed-off-by: Eric Long <eric.l...@spreadtrum.com>
Signed-off-by: Baolin Wang <baolin.w...@linaro.org>
---
 drivers/dma/sprd-dma.c       |  215 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/dma/sprd-dma.h |    4 +
 2 files changed, 219 insertions(+)

diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
index a7a89fd..d7c7ffa 100644
--- a/drivers/dma/sprd-dma.c
+++ b/drivers/dma/sprd-dma.c
@@ -100,6 +100,8 @@
 #define SPRD_DMA_DES_DATAWIDTH_OFFSET  28
 #define SPRD_DMA_SWT_MODE_OFFSET       26
 #define SPRD_DMA_REQ_MODE_OFFSET       24
+#define SPRD_DMA_WRAP_SEL_OFFSET       23
+#define SPRD_DMA_WRAP_EN_OFFSET                22
 #define SPRD_DMA_REQ_MODE_MASK         GENMASK(1, 0)
 #define SPRD_DMA_FIX_SEL_OFFSET                21
 #define SPRD_DMA_FIX_EN_OFFSET         20
@@ -154,6 +156,35 @@ struct sprd_dma_chn_hw {
        u32 des_blk_step;
 };
 
+/*
+ * struct sprd_dma_config - DMA configuration structure
+ * @cfg: dma slave channel runtime config
+ * @src_addr: the source physical address
+ * @dst_addr: the destination physical address
+ * @block_len: specify one block transfer length
+ * @transcation_len: specify one transcation transfer length
+ * @src_step: source transfer step
+ * @dst_step: destination transfer step
+ * @wrap_ptr: wrap pointer address, once the transfer address reaches the
+ * 'wrap_ptr', the next transfer address will jump to the 'wrap_to' address.
+ * @wrap_to: wrap jump to address
+ * @req_mode: specify the DMA request mode
+ * @int_mode: specify the DMA interrupt type
+ */
+struct sprd_dma_config {
+       struct dma_slave_config cfg;
+       phys_addr_t src_addr;
+       phys_addr_t dst_addr;
+       u32 block_len;
+       u32 transcation_len;
+       u32 src_step;
+       u32 dst_step;
+       phys_addr_t wrap_ptr;
+       phys_addr_t wrap_to;
+       enum sprd_dma_req_mode req_mode;
+       enum sprd_dma_int_type int_mode;
+};
+
 /* dma request description */
 struct sprd_dma_desc {
        struct virt_dma_desc    vd;
@@ -164,6 +195,7 @@ struct sprd_dma_desc {
 struct sprd_dma_chn {
        struct virt_dma_chan    vc;
        void __iomem            *chn_base;
+       struct sprd_dma_config  slave_cfg;
        u32                     chn_num;
        u32                     dev_id;
        struct sprd_dma_desc    *cur_desc;
@@ -552,6 +584,121 @@ static void sprd_dma_issue_pending(struct dma_chan *chan)
        spin_unlock_irqrestore(&schan->vc.lock, flags);
 }
 
+static enum sprd_dma_datawidth
+sprd_dma_get_datawidth(enum dma_slave_buswidth buswidth)
+{
+       switch (buswidth) {
+       case DMA_SLAVE_BUSWIDTH_1_BYTE:
+               return SPRD_DMA_DATAWIDTH_1_BYTE;
+
+       case DMA_SLAVE_BUSWIDTH_2_BYTES:
+               return SPRD_DMA_DATAWIDTH_2_BYTES;
+
+       case DMA_SLAVE_BUSWIDTH_4_BYTES:
+               return SPRD_DMA_DATAWIDTH_4_BYTES;
+
+       case DMA_SLAVE_BUSWIDTH_8_BYTES:
+               return SPRD_DMA_DATAWIDTH_8_BYTES;
+
+       default:
+               return SPRD_DMA_DATAWIDTH_4_BYTES;
+       }
+}
+
+static u32 sprd_dma_get_step(enum sprd_dma_datawidth datawidth)
+{
+       switch (datawidth) {
+       case SPRD_DMA_DATAWIDTH_1_BYTE:
+               return SPRD_DMA_BYTE_STEP;
+
+       case SPRD_DMA_DATAWIDTH_2_BYTES:
+               return SPRD_DMA_SHORT_STEP;
+
+       case SPRD_DMA_DATAWIDTH_4_BYTES:
+               return SPRD_DMA_WORD_STEP;
+
+       case SPRD_DMA_DATAWIDTH_8_BYTES:
+               return SPRD_DMA_DWORD_STEP;
+
+       default:
+               return SPRD_DMA_DWORD_STEP;
+       }
+}
+
+static int sprd_dma_config(struct dma_chan *chan, struct sprd_dma_desc *sdesc,
+                          struct sprd_dma_config *slave_cfg)
+{
+       struct sprd_dma_dev *sdev = to_sprd_dma_dev(chan);
+       struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+       struct sprd_dma_chn_hw *hw = &sdesc->chn_hw;
+       u32 fix_mode = 0, fix_en = 0, wrap_en = 0, wrap_mode = 0;
+       u32 src_datawidth, dst_datawidth;
+
+       if (slave_cfg->cfg.slave_id)
+               schan->dev_id = slave_cfg->cfg.slave_id;
+
+       hw->cfg = SPRD_DMA_DONOT_WAIT_BDONE << SPRD_DMA_WAIT_BDONE_OFFSET;
+       hw->wrap_ptr = (u32)((slave_cfg->wrap_ptr & SPRD_DMA_LOW_ADDR_MASK) |
+               ((slave_cfg->src_addr >> SPRD_DMA_HIGH_ADDR_OFFSET) &
+                SPRD_DMA_HIGH_ADDR_MASK));
+       hw->wrap_to = (u32)((slave_cfg->wrap_to & SPRD_DMA_LOW_ADDR_MASK) |
+               ((slave_cfg->dst_addr >> SPRD_DMA_HIGH_ADDR_OFFSET) &
+                SPRD_DMA_HIGH_ADDR_MASK));
+
+       hw->src_addr = (u32)(slave_cfg->src_addr & SPRD_DMA_LOW_ADDR_MASK);
+       hw->des_addr = (u32)(slave_cfg->dst_addr & SPRD_DMA_LOW_ADDR_MASK);
+
+       if ((slave_cfg->src_step != 0 && slave_cfg->dst_step != 0)
+           || (slave_cfg->src_step | slave_cfg->dst_step) == 0) {
+               fix_en = 0;
+       } else {
+               fix_en = 1;
+               if (slave_cfg->src_step)
+                       fix_mode = 1;
+               else
+                       fix_mode = 0;
+       }
+
+       if (slave_cfg->wrap_ptr && slave_cfg->wrap_to) {
+               wrap_en = 1;
+               if (slave_cfg->wrap_to == slave_cfg->src_addr) {
+                       wrap_mode = 0;
+               } else if (slave_cfg->wrap_to == slave_cfg->dst_addr) {
+                       wrap_mode = 1;
+               } else {
+                       dev_err(sdev->dma_dev.dev, "invalid wrap mode\n");
+                       return -EINVAL;
+               }
+       }
+
+       hw->intc = slave_cfg->int_mode | SPRD_DMA_CFG_ERR_INT_EN;
+
+       src_datawidth = sprd_dma_get_datawidth(slave_cfg->cfg.src_addr_width);
+       dst_datawidth = sprd_dma_get_datawidth(slave_cfg->cfg.dst_addr_width);
+       hw->frg_len = src_datawidth << SPRD_DMA_SRC_DATAWIDTH_OFFSET |
+               dst_datawidth << SPRD_DMA_DES_DATAWIDTH_OFFSET |
+               slave_cfg->req_mode << SPRD_DMA_REQ_MODE_OFFSET |
+               wrap_mode << SPRD_DMA_WRAP_SEL_OFFSET |
+               wrap_en << SPRD_DMA_WRAP_EN_OFFSET |
+               fix_mode << SPRD_DMA_FIX_SEL_OFFSET |
+               fix_en << SPRD_DMA_FIX_EN_OFFSET |
+               (slave_cfg->cfg.src_maxburst & SPRD_DMA_FRG_LEN_MASK);
+
+       hw->blk_len = slave_cfg->block_len & SPRD_DMA_BLK_LEN_MASK;
+
+       hw->trsc_len = slave_cfg->transcation_len & SPRD_DMA_TRSC_LEN_MASK;
+
+       hw->trsf_step = (slave_cfg->dst_step & SPRD_DMA_TRSF_STEP_MASK) <<
+                       SPRD_DMA_DEST_TRSF_STEP_OFFSET |
+                       (slave_cfg->src_step & SPRD_DMA_TRSF_STEP_MASK) <<
+                       SPRD_DMA_SRC_TRSF_STEP_OFFSET;
+
+       hw->frg_step = 0;
+       hw->src_blk_step = 0;
+       hw->des_blk_step = 0;
+       return 0;
+}
+
 static 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)
@@ -606,6 +753,72 @@ static void sprd_dma_issue_pending(struct dma_chan *chan)
        return vchan_tx_prep(&schan->vc, &sdesc->vd, flags);
 }
 
+static struct dma_async_tx_descriptor *
+sprd_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
+                      unsigned int sglen, enum dma_transfer_direction dir,
+                      unsigned long flags, void *context)
+{
+       struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+       struct sprd_dma_config *slave_cfg = &schan->slave_cfg;
+       struct sprd_dma_desc *sdesc;
+       struct scatterlist *sg;
+       int ret, i;
+
+       /* TODO: now we only support one sg for each DMA configuration. */
+       if (!is_slave_direction(dir) || sglen > 1)
+               return NULL;
+
+       sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);
+       if (!sdesc)
+               return NULL;
+
+       for_each_sg(sgl, sg, sglen, i) {
+               if (dir == DMA_MEM_TO_DEV) {
+                       slave_cfg->src_addr = sg_dma_address(sg);
+                       slave_cfg->dst_addr = slave_cfg->cfg.dst_addr;
+                       slave_cfg->src_step =
+                       sprd_dma_get_step(slave_cfg->cfg.src_addr_width);
+                       slave_cfg->dst_step = SPRD_DMA_NONE_STEP;
+               } else {
+                       slave_cfg->src_addr = slave_cfg->cfg.src_addr;
+                       slave_cfg->dst_addr = sg_dma_address(sg);
+                       slave_cfg->src_step = SPRD_DMA_NONE_STEP;
+                       slave_cfg->dst_step =
+                       sprd_dma_get_step(slave_cfg->cfg.dst_addr_width);
+               }
+
+               slave_cfg->block_len = sg_dma_len(sg);
+               slave_cfg->transcation_len = sg_dma_len(sg);
+       }
+
+       slave_cfg->req_mode =
+               (flags >> SPRD_DMA_REQ_SHIFT) & SPRD_DMA_REQ_MODE_MASK;
+       slave_cfg->int_mode = flags & SPRD_DMA_INT_MASK;
+
+       ret = sprd_dma_config(chan, sdesc, slave_cfg);
+       if (ret) {
+               kfree(sdesc);
+               return NULL;
+       }
+
+       return vchan_tx_prep(&schan->vc, &sdesc->vd, flags);
+}
+
+static int sprd_dma_slave_config(struct dma_chan *chan,
+                                struct dma_slave_config *config)
+{
+       struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+       struct sprd_dma_config *slave_cfg = &schan->slave_cfg;
+
+       if (!is_slave_direction(config->direction))
+               return -EINVAL;
+
+       memset(slave_cfg, 0, sizeof(*slave_cfg));
+       memcpy(&slave_cfg->cfg, config, sizeof(*config));
+
+       return 0;
+}
+
 static int sprd_dma_pause(struct dma_chan *chan)
 {
        struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
@@ -733,6 +946,8 @@ static int sprd_dma_probe(struct platform_device *pdev)
        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_prep_slave_sg = sprd_dma_prep_slave_sg;
+       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_dma_terminate_all;
diff --git a/include/linux/dma/sprd-dma.h b/include/linux/dma/sprd-dma.h
index c545162..b0115e3 100644
--- a/include/linux/dma/sprd-dma.h
+++ b/include/linux/dma/sprd-dma.h
@@ -3,6 +3,10 @@
 #ifndef _SPRD_DMA_H_
 #define _SPRD_DMA_H_
 
+#define SPRD_DMA_REQ_SHIFT 16
+#define SPRD_DMA_FLAGS(req_mode, int_type) \
+       ((req_mode) << SPRD_DMA_REQ_SHIFT | (int_type))
+
 /*
  * enum sprd_dma_req_mode: define the DMA request mode
  * @SPRD_DMA_FRAG_REQ: fragment request mode
-- 
1.7.9.5

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