From mboxrd@z Thu Jan 1 00:00:00 1970 From: zonque@gmail.com (Daniel Mack) Date: Wed, 7 Aug 2013 12:19:29 +0200 Subject: [PATCH 11/12] dma: mmp_pdma: add support for residue reporting In-Reply-To: <1375870770-14263-1-git-send-email-zonque@gmail.com> References: <1375870770-14263-1-git-send-email-zonque@gmail.com> Message-ID: <1375870770-14263-12-git-send-email-zonque@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org In order to report the channel's residue, we have to memorize the first dma buffer position when the channel is configured. Signed-off-by: Daniel Mack --- drivers/dma/mmp_pdma.c | 39 +++++++++++++++++++++++++++++++++++++-- 1 file changed, 37 insertions(+), 2 deletions(-) diff --git a/drivers/dma/mmp_pdma.c b/drivers/dma/mmp_pdma.c index c56da7c..0c4a2d5 100644 --- a/drivers/dma/mmp_pdma.c +++ b/drivers/dma/mmp_pdma.c @@ -28,8 +28,8 @@ #define DALGN 0x00a0 #define DINT 0x00f0 #define DDADR 0x0200 -#define DSADR 0x0204 -#define DTADR 0x0208 +#define DSADR(n) (0x0204 + ((n) << 4)) +#define DTADR(n) (0x0208 + ((n) << 4)) #define DCMD 0x020c #define DCSR_RUN (1 << 31) /* Run Bit (read / write) */ @@ -97,6 +97,13 @@ struct mmp_pdma_chan { struct dma_async_tx_descriptor desc; struct mmp_pdma_phy *phy; enum dma_transfer_direction dir; + /* + * We memorize the original start address of the first descriptor as + * well as the original total length so we can later determine the + * channel's residue. + */ + dma_addr_t start_addr; + u32 total_len; /* channel's basic info */ struct tasklet_struct tasklet; @@ -469,6 +476,13 @@ mmp_pdma_prep_memcpy(struct dma_chan *dchan, chan->dcmd |= DCMD_BURST32; } + if (chan->dir == DMA_MEM_TO_DEV) + chan->start_addr = dma_src; + else + chan->start_addr = dma_dst; + + chan->total_len = len; + do { /* Allocate the link descriptor from DMA pool */ new = mmp_pdma_alloc_descriptor(chan); @@ -540,11 +554,17 @@ mmp_pdma_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl, return NULL; chan->byte_align = false; + chan->total_len = 0; for_each_sg(sgl, sg, sg_len, i) { addr = sg_dma_address(sg); avail = sg_dma_len(sgl); + if (!first) + chan->start_addr = addr; + + chan->total_len += avail; + do { len = min_t(size_t, avail, PDMA_MAX_DESC_BYTES); if (addr & 0x7) @@ -671,6 +691,20 @@ static int mmp_pdma_control(struct dma_chan *dchan, enum dma_ctrl_cmd cmd, return ret; } +static unsigned int mmp_pdma_residue(struct mmp_pdma_chan *chan) +{ + u32 curr, done; + + if (chan->dir == DMA_DEV_TO_MEM) + curr = readl(chan->phy->base + DTADR(chan->phy->idx)); + else + curr = readl(chan->phy->base + DSADR(chan->phy->idx)); + + done = curr - chan->start_addr; + + return chan->total_len - done; +} + static enum dma_status mmp_pdma_tx_status(struct dma_chan *dchan, dma_cookie_t cookie, struct dma_tx_state *txstate) { @@ -680,6 +714,7 @@ static enum dma_status mmp_pdma_tx_status(struct dma_chan *dchan, spin_lock_irqsave(&chan->desc_lock, flags); ret = dma_cookie_status(dchan, cookie, txstate); + txstate->residue = mmp_pdma_residue(chan); spin_unlock_irqrestore(&chan->desc_lock, flags); return ret; -- 1.8.3.1