From 62971b29825adb06908bad81e7679d1f7904b24d Mon Sep 17 00:00:00 2001 From: Ludovic Desroches Date: Thu, 13 Jun 2013 10:39:39 +0200 Subject: dmaengine: at_hdmac: add FIFO configuration parameter to DMA DT binding For most devices the FIFO configuration is the same i.e. when half FIFO size is available/filled, a source/destination request is serviced. But USART devices have to do it when there is enough space/data available to perform a single AHB access so the ASAP configuration. Acked-by: Nicolas Ferre Acked-by: Jean-Christophe PLAGNIOL-VILLARD Signed-off-by: Ludovic Desroches Signed-off-by: Nicolas Ferre --- drivers/dma/at_hdmac.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) (limited to 'drivers/dma/at_hdmac.c') diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c index 6db5228f4134..b7050a46bd87 100644 --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -14,6 +14,7 @@ * found on AT91SAM9263. */ +#include #include #include #include @@ -1320,15 +1321,31 @@ static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec, atslave = devm_kzalloc(&dmac_pdev->dev, sizeof(*atslave), GFP_KERNEL); if (!atslave) return NULL; + + atslave->cfg = ATC_DST_H2SEL_HW | ATC_SRC_H2SEL_HW; /* * We can fill both SRC_PER and DST_PER, one of these fields will be * ignored depending on DMA transfer direction. */ - per_id = dma_spec->args[1]; - atslave->cfg = ATC_FIFOCFG_HALFFIFO - | ATC_DST_H2SEL_HW | ATC_SRC_H2SEL_HW - | ATC_DST_PER_MSB(per_id) | ATC_DST_PER(per_id) + per_id = dma_spec->args[1] & AT91_DMA_CFG_PER_ID_MASK; + atslave->cfg |= ATC_DST_PER_MSB(per_id) | ATC_DST_PER(per_id) | ATC_SRC_PER_MSB(per_id) | ATC_SRC_PER(per_id); + /* + * We have to translate the value we get from the device tree since + * the half FIFO configuration value had to be 0 to keep backward + * compatibility. + */ + switch (dma_spec->args[1] & AT91_DMA_CFG_FIFOCFG_MASK) { + case AT91_DMA_CFG_FIFOCFG_ALAP: + atslave->cfg |= ATC_FIFOCFG_LARGESTBURST; + break; + case AT91_DMA_CFG_FIFOCFG_ASAP: + atslave->cfg |= ATC_FIFOCFG_ENOUGHSPACE; + break; + case AT91_DMA_CFG_FIFOCFG_HALF: + default: + atslave->cfg |= ATC_FIFOCFG_HALFFIFO; + } atslave->dma_dev = &dmac_pdev->dev; chan = dma_request_channel(mask, at_dma_filter, atslave); -- cgit