From: Zhenfang Wang zhenfang.wang@unisoc.com
[ Upstream commit 8b6bc5fd71e677864d1a3b896b3069a6e0c5e214 ]
We will set the link-list pointer register point to next link-list configuration's physical address, which can load DMA configuration from the link-list node automatically.
But the link-list node's physical address can be larger than 32bits, and now Spreadtrum DMA driver only supports 32bits physical address, which may cause loading a incorrect DMA configuration when starting the link-list transfer mode. According to the DMA datasheet, we can use SRC_BLK_STEP register (bit28 - bit31) to save the high bits of the link-list node's physical address to fix this issue.
Fixes: 4ac695464763 ("dmaengine: sprd: Support DMA link-list mode") Signed-off-by: Zhenfang Wang zhenfang.wang@unisoc.com Signed-off-by: Baolin Wang baolin.wang@linaro.org Link: https://lore.kernel.org/r/eadfe9295499efa003e1c344e67e2890f9d1d780.156826706... Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/dma/sprd-dma.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c index 525dc7338fe3b..a4a91f233121a 100644 --- a/drivers/dma/sprd-dma.c +++ b/drivers/dma/sprd-dma.c @@ -134,6 +134,10 @@ #define SPRD_DMA_SRC_TRSF_STEP_OFFSET 0 #define SPRD_DMA_TRSF_STEP_MASK GENMASK(15, 0)
+/* SPRD DMA_SRC_BLK_STEP register definition */ +#define SPRD_DMA_LLIST_HIGH_MASK GENMASK(31, 28) +#define SPRD_DMA_LLIST_HIGH_SHIFT 28 + /* define DMA channel mode & trigger mode mask */ #define SPRD_DMA_CHN_MODE_MASK GENMASK(7, 0) #define SPRD_DMA_TRG_MODE_MASK GENMASK(7, 0) @@ -717,6 +721,7 @@ static int sprd_dma_fill_desc(struct dma_chan *chan, u32 int_mode = flags & SPRD_DMA_INT_MASK; int src_datawidth, dst_datawidth, src_step, dst_step; u32 temp, fix_mode = 0, fix_en = 0; + phys_addr_t llist_ptr;
if (dir == DMA_MEM_TO_DEV) { src_step = sprd_dma_get_step(slave_cfg->src_addr_width); @@ -814,13 +819,16 @@ static int sprd_dma_fill_desc(struct dma_chan *chan, * Set the link-list pointer point to next link-list * configuration's physical address. */ - hw->llist_ptr = schan->linklist.phy_addr + temp; + llist_ptr = schan->linklist.phy_addr + temp; + hw->llist_ptr = lower_32_bits(llist_ptr); + hw->src_blk_step = (upper_32_bits(llist_ptr) << SPRD_DMA_LLIST_HIGH_SHIFT) & + SPRD_DMA_LLIST_HIGH_MASK; } else { hw->llist_ptr = 0; + hw->src_blk_step = 0; }
hw->frg_step = 0; - hw->src_blk_step = 0; hw->des_blk_step = 0; return 0; }