[RESEND PATCH v3 4/6] dmaengine: stm32-dmamux: set dmamux channel id in dma features bitfield

Amelie Delaunay
2022-08-29T15:47:23Z

STM32 DMAMUX is used with STM32 DMA1 and DMA2:
- DMAMUX channels 0 to 7 are connected to DMA1 channels 0 to 7
- DMAMUX channels 8 to 15 are connected to DMA2 channels 0 to 7

STM32 MDMA can be triggered by DMA1 and DMA2 channels transfer complete,
and the "request line number" is the DMAMUX channel id (e.g. DMA2 channel 0
triggers MDMA with request line 8).

To well configure MDMA, set DMAMUX channel id in DMA features bitfield,
so that DMA can update struct dma_slave_config peripheral_config properly.

Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
---
drivers/dma/stm32-dmamux.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/stm32-dmamux.c b/drivers/dma/stm32-dmamux.c
index eee0c5aa5fb5..b431f9da9206 100644
--- a/drivers/dma/stm32-dmamux.c
+++ b/drivers/dma/stm32-dmamux.c
@@ -147,7 +147,7 @@ static void *stm32_dmamux_route_allocate(struct of_phandle_args *dma_spec,
mux->request = dma_spec->args[0];

/* craft DMA spec */
- dma_spec->args[3] = dma_spec->args[2];
+ dma_spec->args[3] = dma_spec->args[2] | mux->chan_id << 16;
dma_spec->args[2] = dma_spec->args[1];
dma_spec->args[1] = 0;
dma_spec->args[0] = mux->chan_id - min;
--
2.25.1