[PATCH 5.4 031/108] spi: stm32: Use dma_request_chan() instead dma_request_slave_channel()

Greg Kroah-Hartman
2021-07-26T16:03:50Z

From: Peter Ujfalusi <peter.ujfalusi@ti.com>

[ Upstream commit 0a454258febb73e4c60d7f5d9a02d1a8c64fdfb8 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/spi/spi-stm32.c | 32 ++++++++++++++++++++++----------
1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index 3af6a5a3a4b2..8c308279c535 100644
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c
@@ -1908,17 +1908,29 @@ 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;
@@ -1930,13 +1942,13 @@ 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_gpios) {
dev_err(&pdev->dev, "no CS gpios available\n");
ret = -EINVAL;
- goto err_dma_release;
+ goto err_pm_disable;
}

for (i = 0; i < master->num_chipselect; i++) {
@@ -1960,13 +1972,13 @@ static int stm32_spi_probe(struct platform_device *pdev)

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:
--
2.30.2