From 6fc4573c4e17eb57f6e1a20992dcf0b6a105afdb Mon Sep 17 00:00:00 2001 From: Daniel Mack Date: Sat, 10 Aug 2013 18:52:22 +0200 Subject: [PATCH] dma: mmp_pdma: add support for byte-aligned transfers The PXA DMA controller has a DALGN register which allows for byte-aligned DMA transfers. Use it in case any of the transfer descriptors is not aligned to a mask of ~0x7. Signed-off-by: Daniel Mack Acked-by: Arnd Bergmann Signed-off-by: Vinod Koul --- drivers/dma/mmp_pdma.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/dma/mmp_pdma.c b/drivers/dma/mmp_pdma.c index b426e55f8316..dba9fe9cbbbe 100644 --- a/drivers/dma/mmp_pdma.c +++ b/drivers/dma/mmp_pdma.c @@ -109,6 +109,7 @@ struct mmp_pdma_chan { struct list_head chain_pending; /* Link descriptors queue for pending */ struct list_head chain_running; /* Link descriptors queue for running */ bool idle; /* channel statue machine */ + bool byte_align; struct dma_pool *desc_pool; /* Descriptors pool */ }; @@ -142,7 +143,7 @@ static void set_desc(struct mmp_pdma_phy *phy, dma_addr_t addr) static void enable_chan(struct mmp_pdma_phy *phy) { - u32 reg; + u32 reg, dalgn; if (!phy->vchan) return; @@ -150,6 +151,13 @@ static void enable_chan(struct mmp_pdma_phy *phy) reg = DRCMR(phy->vchan->drcmr); writel(DRCMR_MAPVLD | phy->idx, phy->base + reg); + dalgn = readl(phy->base + DALGN); + if (phy->vchan->byte_align) + dalgn |= 1 << phy->idx; + else + dalgn &= ~(1 << phy->idx); + writel(dalgn, phy->base + DALGN); + reg = (phy->idx << 2) + DCSR; writel(readl(phy->base + reg) | DCSR_RUN, phy->base + reg); @@ -455,6 +463,7 @@ mmp_pdma_prep_memcpy(struct dma_chan *dchan, return NULL; chan = to_mmp_pdma_chan(dchan); + chan->byte_align = false; if (!chan->dir) { chan->dir = DMA_MEM_TO_MEM; @@ -471,6 +480,8 @@ mmp_pdma_prep_memcpy(struct dma_chan *dchan, } copy = min_t(size_t, len, PDMA_MAX_DESC_BYTES); + if (dma_src & 0x7 || dma_dst & 0x7) + chan->byte_align = true; new->desc.dcmd = chan->dcmd | (DCMD_LENGTH & copy); new->desc.dsadr = dma_src; @@ -530,12 +541,16 @@ mmp_pdma_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl, if ((sgl == NULL) || (sg_len == 0)) return NULL; + chan->byte_align = false; + for_each_sg(sgl, sg, sg_len, i) { addr = sg_dma_address(sg); avail = sg_dma_len(sgl); do { len = min_t(size_t, avail, PDMA_MAX_DESC_BYTES); + if (addr & 0x7) + chan->byte_align = true; /* allocate and populate the descriptor */ new = mmp_pdma_alloc_descriptor(chan); -- 2.20.1