From 0be035f3485379d812d617ee7eaa255cde97dbfa Mon Sep 17 00:00:00 2001 From: Feng Tang Date: Thu, 2 Dec 2010 17:14:30 +0800 Subject: [PATCH] intel_mid_dma: add support for single item scatter-gather list Current driver's device_prep_slave_sg can't be used by DMAC2 even the sg list contains one item, this patch will enable DMAC2 to use this API. Signed-off-by: Feng Tang Acked-by: Vinod Koul Signed-off-by: Dan Williams --- drivers/dma/intel_mid_dma.c | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-) diff --git a/drivers/dma/intel_mid_dma.c b/drivers/dma/intel_mid_dma.c index 41941d05bfb9..0c0feb8834d0 100644 --- a/drivers/dma/intel_mid_dma.c +++ b/drivers/dma/intel_mid_dma.c @@ -664,11 +664,20 @@ static struct dma_async_tx_descriptor *intel_mid_dma_prep_memcpy( /*calculate CTL_LO*/ ctl_lo.ctl_lo = 0; ctl_lo.ctlx.int_en = 1; - ctl_lo.ctlx.dst_tr_width = mids->dma_slave.dst_addr_width; - ctl_lo.ctlx.src_tr_width = mids->dma_slave.src_addr_width; ctl_lo.ctlx.dst_msize = mids->dma_slave.src_maxburst; ctl_lo.ctlx.src_msize = mids->dma_slave.dst_maxburst; + /* + * Here we need some translation from "enum dma_slave_buswidth" + * to the format for our dma controller + * standard intel_mid_dmac's format + * 1 Byte 0b000 + * 2 Bytes 0b001 + * 4 Bytes 0b010 + */ + ctl_lo.ctlx.dst_tr_width = mids->dma_slave.dst_addr_width / 2; + ctl_lo.ctlx.src_tr_width = mids->dma_slave.src_addr_width / 2; + if (mids->cfg_mode == LNW_DMA_MEM_TO_MEM) { ctl_lo.ctlx.tt_fc = 0; ctl_lo.ctlx.sinc = 0; @@ -746,8 +755,18 @@ static struct dma_async_tx_descriptor *intel_mid_dma_prep_slave_sg( BUG_ON(!mids); if (!midc->dma->pimr_mask) { - pr_debug("MDMA: SG list is not supported by this controller\n"); - return NULL; + /* We can still handle sg list with only one item */ + if (sg_len == 1) { + txd = intel_mid_dma_prep_memcpy(chan, + mids->dma_slave.dst_addr, + mids->dma_slave.src_addr, + sgl->length, + flags); + return txd; + } else { + pr_warn("MDMA: SG list is not supported by this controller\n"); + return NULL; + } } pr_debug("MDMA: SG Length = %d, direction = %d, Flags = %#lx\n", @@ -758,6 +777,7 @@ static struct dma_async_tx_descriptor *intel_mid_dma_prep_slave_sg( pr_err("MDMA: Prep memcpy failed\n"); return NULL; } + desc = to_intel_mid_dma_desc(txd); desc->dirn = direction; ctl_lo.ctl_lo = desc->ctl_lo; -- 2.20.1