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authorEric Long <eric.long@unisoc.com>2019-10-23 09:31:32 +0300
committerVinod Koul <vkoul@kernel.org>2019-11-14 13:33:35 +0300
commita7e335deed174a37fc6f84f69caaeff8a08f8ff8 (patch)
tree314cc2e8b386ce86a2276291b8404952dacabc8e /drivers
parentbb5a471de9bfd0853d48d8dc5572469778c2824d (diff)
downloadlinux-a7e335deed174a37fc6f84f69caaeff8a08f8ff8.tar.xz
dmaengine: sprd: Add wrap address support for link-list mode
The Spreadtrum Audio compress offload mode will use 2-stage DMA transfer to save power. That means we can request 2 dma channels, one for source channel, and another one for destination channel. Once the source channel's transaction is done, it will trigger the destination channel's transaction automatically by hardware signal. In this case, the source channel will transfer data from IRAM buffer to the DSP fifo to decoding/encoding, once IRAM buffer is empty by transferring done, the destination channel will start to transfer data from DDR buffer to IRAM buffer. Since the destination channel will use link-list mode to fill the IRAM data, and IRAM buffer is allocated by 32K, and DDR buffer is larger to 2M, that means we need lots of link-list nodes to do a cyclic transfer, instead wasting lots of link-list memory, we can use wrap address support to reduce link-list node number, which means when the transfer address reaches the wrap address, the transfer address will jump to the wrap_to address specified by wrap_to register, and only 2 link-list nodes can do a cyclic transfer to transfer data from DDR to IRAM. Thus this patch adds wrap address to support this case. [Baolin Wang changes the commit message] Signed-off-by: Eric Long <eric.long@unisoc.com> Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Link: https://lore.kernel.org/r/85a5484bc1f3dd53ce6f92700ad8b35f30a0b096.1571812029.git.baolin.wang@linaro.org Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/dma/sprd-dma.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
index 32402c2615de..9a31a315dbef 100644
--- a/drivers/dma/sprd-dma.c
+++ b/drivers/dma/sprd-dma.c
@@ -99,6 +99,7 @@
/* DMA_CHN_WARP_* register definition */
#define SPRD_DMA_HIGH_ADDR_MASK GENMASK(31, 28)
#define SPRD_DMA_LOW_ADDR_MASK GENMASK(31, 0)
+#define SPRD_DMA_WRAP_ADDR_MASK GENMASK(27, 0)
#define SPRD_DMA_HIGH_ADDR_OFFSET 4
/* SPRD_DMA_CHN_INTC register definition */
@@ -118,6 +119,8 @@
#define SPRD_DMA_SWT_MODE_OFFSET 26
#define SPRD_DMA_REQ_MODE_OFFSET 24
#define SPRD_DMA_REQ_MODE_MASK GENMASK(1, 0)
+#define SPRD_DMA_WRAP_SEL_DEST BIT(23)
+#define SPRD_DMA_WRAP_EN BIT(22)
#define SPRD_DMA_FIX_SEL_OFFSET 21
#define SPRD_DMA_FIX_EN_OFFSET 20
#define SPRD_DMA_LLIST_END BIT(19)
@@ -804,6 +807,8 @@ static int sprd_dma_fill_desc(struct dma_chan *chan,
temp |= req_mode << SPRD_DMA_REQ_MODE_OFFSET;
temp |= fix_mode << SPRD_DMA_FIX_SEL_OFFSET;
temp |= fix_en << SPRD_DMA_FIX_EN_OFFSET;
+ temp |= schan->linklist.wrap_addr ?
+ SPRD_DMA_WRAP_EN | SPRD_DMA_WRAP_SEL_DEST : 0;
temp |= slave_cfg->src_maxburst & SPRD_DMA_FRG_LEN_MASK;
hw->frg_len = temp;
@@ -831,6 +836,12 @@ static int sprd_dma_fill_desc(struct dma_chan *chan,
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;
+
+ if (schan->linklist.wrap_addr) {
+ hw->wrap_ptr |= schan->linklist.wrap_addr &
+ SPRD_DMA_WRAP_ADDR_MASK;
+ hw->wrap_to |= dst & SPRD_DMA_WRAP_ADDR_MASK;
+ }
} else {
hw->llist_ptr = 0;
hw->src_blk_step = 0;
@@ -939,9 +950,11 @@ sprd_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
schan->linklist.phy_addr = ll_cfg->phy_addr;
schan->linklist.virt_addr = ll_cfg->virt_addr;
+ schan->linklist.wrap_addr = ll_cfg->wrap_addr;
} else {
schan->linklist.phy_addr = 0;
schan->linklist.virt_addr = 0;
+ schan->linklist.wrap_addr = 0;
}
/*