spi: stm32: Use dma_request_chan() instead dma_request_slave_channel()

dma_request_slave_channel() is a wrapper on top of dma_request_chan()
eating up the error code.

By using dma_request_chan() directly the driver can support deferred
probing against DMA.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20191212135550.4634-10-peter.ujfalusi@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index 7d75632c415195c3e176cd4b3bc3883adec73006..e041f9c4ec47e861e75ca8fe60f5a3ced663124f 100644 (file)
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c
@@ -1879,17 +1879,29 @@ static int stm32_spi_probe(struct platform_device *pdev)
        master->transfer_one = stm32_spi_transfer_one;
        master->unprepare_message = stm32_spi_unprepare_msg;
 
-       spi->dma_tx = dma_request_slave_channel(spi->dev, "tx");
-       if (!spi->dma_tx)
+       spi->dma_tx = dma_request_chan(spi->dev, "tx");
+       if (IS_ERR(spi->dma_tx)) {
+               ret = PTR_ERR(spi->dma_tx);
+               spi->dma_tx = NULL;
+               if (ret == -EPROBE_DEFER)
+                       goto err_clk_disable;
+
                dev_warn(&pdev->dev, "failed to request tx dma channel\n");
-       else
+       } else {
                master->dma_tx = spi->dma_tx;
+       }
+
+       spi->dma_rx = dma_request_chan(spi->dev, "rx");
+       if (IS_ERR(spi->dma_rx)) {
+               ret = PTR_ERR(spi->dma_rx);
+               spi->dma_rx = NULL;
+               if (ret == -EPROBE_DEFER)
+                       goto err_dma_release;
 
-       spi->dma_rx = dma_request_slave_channel(spi->dev, "rx");
-       if (!spi->dma_rx)
                dev_warn(&pdev->dev, "failed to request rx dma channel\n");
-       else
+       } else {
                master->dma_rx = spi->dma_rx;
+       }
 
        if (spi->dma_tx || spi->dma_rx)
                master->can_dma = stm32_spi_can_dma;
@@ -1901,26 +1913,26 @@ static int stm32_spi_probe(struct platform_device *pdev)
        if (ret) {
                dev_err(&pdev->dev, "spi master registration failed: %d\n",
                        ret);
-               goto err_dma_release;
+               goto err_pm_disable;
        }
 
        if (!master->cs_gpiods) {
                dev_err(&pdev->dev, "no CS gpios available\n");
                ret = -EINVAL;
-               goto err_dma_release;
+               goto err_pm_disable;
        }
 
        dev_info(&pdev->dev, "driver initialized\n");
 
        return 0;
 
+err_pm_disable:
+       pm_runtime_disable(&pdev->dev);
 err_dma_release:
        if (spi->dma_tx)
                dma_release_channel(spi->dma_tx);
        if (spi->dma_rx)
                dma_release_channel(spi->dma_rx);
-
-       pm_runtime_disable(&pdev->dev);
 err_clk_disable:
        clk_disable_unprepare(spi->clk);
 err_master_put: