dmaengine: fsl-edma: fix eDMAv4 channel allocation issue

[ Upstream commit dc51b4442dd94ab12c146c1897bbdb40e16d5636 ]

The eDMAv4 channel mux has a limitation where certain requests must use
even channels, while others must use odd numbers.

Add two flags (ARGS_EVEN_CH and ARGS_ODD_CH) to reflect this limitation.
The device tree source (dts) files need to be updated accordingly.

This issue was identified by the following commit:
commit a725990557e7 ("arm64: dts: imx93: Fix the dmas entries order")

Reverting channel orders triggered this problem.

Fixes: 72f5801a4e2b ("dmaengine: fsl-edma: integrate v3 support")
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20231114154824.3617255-2-Frank.Li@nxp.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/dma/fsl-edma-main.c b/drivers/dma/fsl-edma-main.c
index 00cb70a..30df55d 100644 (file)
--- a/drivers/dma/fsl-edma-main.c
+++ b/drivers/dma/fsl-edma-main.c
@@ -26,6 +26,8 @@
 #define ARGS_RX                         BIT(0)
 #define ARGS_REMOTE                     BIT(1)
 #define ARGS_MULTI_FIFO                 BIT(2)
+#define ARGS_EVEN_CH                    BIT(3)
+#define ARGS_ODD_CH                     BIT(4)
 
 static void fsl_edma_synchronize(struct dma_chan *chan)
 {
@@ -159,6 +161,12 @@ static struct dma_chan *fsl_edma3_xlate(struct of_phandle_args *dma_spec,
                fsl_chan->is_remote = dma_spec->args[2] & ARGS_REMOTE;
                fsl_chan->is_multi_fifo = dma_spec->args[2] & ARGS_MULTI_FIFO;
 
+               if ((dma_spec->args[2] & ARGS_EVEN_CH) && (i & 0x1))
+                       continue;
+
+               if ((dma_spec->args[2] & ARGS_ODD_CH) && !(i & 0x1))
+                       continue;
+
                if (!b_chmux && i == dma_spec->args[0]) {
                        chan = dma_get_slave_channel(chan);
                        chan->device->privatecnt++;