dmaengine: stm32-dma3: defer channel registration to specify channel name

On STM32 DMA3, channels can be reserved, so they are non available for
Linux. This non-availability creates a mismatch between dma_chan id and
DMA3 channel id.

Use dma_async_device_channel_register() to register the channels
after controller registration and change the default channel name, so that
it can match the name in the Reference Manual and ease requesting a channel
thanks to its name.

Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Link: https://lore.kernel.org/r/20240531150712.2503554-12-amelie.delaunay@foss.st.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/stm32/stm32-dma3.c b/drivers/dma/stm32/stm32-dma3.c
index 66d5129f4822a2e12308f32fa77d5a346877539e..4087e0263a485bb8e86c354b5a68fb4a60adc8a7 100644 (file)
--- a/drivers/dma/stm32/stm32-dma3.c
+++ b/drivers/dma/stm32/stm32-dma3.c
@@ -1732,9 +1732,6 @@ static int stm32_dma3_probe(struct platform_device *pdev)
                chan->fifo_size = get_chan_hwcfg(i, G_FIFO_SIZE(i), hwcfgr);
                /* If chan->fifo_size > 0 then half of the fifo size, else no burst when no FIFO */
                chan->max_burst = (chan->fifo_size) ? (1 << (chan->fifo_size + 1)) / 2 : 0;
-               chan->vchan.desc_free = stm32_dma3_chan_vdesc_free;
-
-               vchan_init(&chan->vchan, dma_dev);
        }
 
        ret = dmaenginem_async_device_register(dma_dev);
@@ -1742,14 +1739,26 @@ static int stm32_dma3_probe(struct platform_device *pdev)
                goto err_clk_disable;
 
        for (i = 0; i < ddata->dma_channels; i++) {
+               char name[12];
+
                if (chan_reserved & BIT(i))
                        continue;
 
+               chan = &ddata->chans[i];
+               snprintf(name, sizeof(name), "dma%dchan%d", ddata->dma_dev.dev_id, chan->id);
+
+               chan->vchan.desc_free = stm32_dma3_chan_vdesc_free;
+               vchan_init(&chan->vchan, dma_dev);
+
+               ret = dma_async_device_channel_register(&ddata->dma_dev, &chan->vchan.chan, name);
+               if (ret) {
+                       dev_err_probe(&pdev->dev, ret, "Failed to register channel %s\n", name);
+                       goto err_clk_disable;
+               }
+
                ret = platform_get_irq(pdev, i);
                if (ret < 0)
                        goto err_clk_disable;
-
-               chan = &ddata->chans[i];
                chan->irq = ret;
 
                ret = devm_request_irq(&pdev->dev, chan->irq, stm32_dma3_chan_irq, 0,