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 <nicolas.ferre@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 6db5228..b7050a4 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -14,6 +14,7 @@
* found on AT91SAM9263.
*/
+#include <dt-bindings/dma/at91.h>
#include <linux/clk.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
@@ -1320,15 +1321,31 @@
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);