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Subject[PATCH] mfd: stm32-timers: Use dma_request_chan() instead dma_request_slave_channel()
Date
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>
---
drivers/mfd/stm32-timers.c | 31 ++++++++++++++++++++++---------
1 file changed, 22 insertions(+), 9 deletions(-)

diff --git a/drivers/mfd/stm32-timers.c b/drivers/mfd/stm32-timers.c
index efcd4b980c94..34747e8a4a40 100644
--- a/drivers/mfd/stm32-timers.c
+++ b/drivers/mfd/stm32-timers.c
@@ -167,10 +167,11 @@ static void stm32_timers_get_arr_size(struct stm32_timers *ddata)
regmap_write(ddata->regmap, TIM_ARR, 0x0);
}

-static void stm32_timers_dma_probe(struct device *dev,
+static int stm32_timers_dma_probe(struct device *dev,
struct stm32_timers *ddata)
{
int i;
+ int ret = 0;
char name[4];

init_completion(&ddata->dma.completion);
@@ -179,14 +180,22 @@ static void stm32_timers_dma_probe(struct device *dev,
/* Optional DMA support: get valid DMA channel(s) or NULL */
for (i = STM32_TIMERS_DMA_CH1; i <= STM32_TIMERS_DMA_CH4; i++) {
snprintf(name, ARRAY_SIZE(name), "ch%1d", i + 1);
- ddata->dma.chans[i] = dma_request_slave_channel(dev, name);
+ ddata->dma.chans[i] = dma_request_chan(dev, name);
}
- ddata->dma.chans[STM32_TIMERS_DMA_UP] =
- dma_request_slave_channel(dev, "up");
- ddata->dma.chans[STM32_TIMERS_DMA_TRIG] =
- dma_request_slave_channel(dev, "trig");
- ddata->dma.chans[STM32_TIMERS_DMA_COM] =
- dma_request_slave_channel(dev, "com");
+ ddata->dma.chans[STM32_TIMERS_DMA_UP] = dma_request_chan(dev, "up");
+ ddata->dma.chans[STM32_TIMERS_DMA_TRIG] = dma_request_chan(dev, "trig");
+ ddata->dma.chans[STM32_TIMERS_DMA_COM] = dma_request_chan(dev, "com");
+
+ for (i = STM32_TIMERS_DMA_CH1; i < STM32_TIMERS_MAX_DMAS; i++) {
+ if (IS_ERR(ddata->dma.chans[i])) {
+ if (PTR_ERR(ddata->dma.chans[i]) == -EPROBE_DEFER)
+ ret = -EPROBE_DEFER;
+
+ ddata->dma.chans[i] = NULL;
+ }
+ }
+
+ return ret;
}

static void stm32_timers_dma_remove(struct device *dev,
@@ -230,7 +239,11 @@ static int stm32_timers_probe(struct platform_device *pdev)

stm32_timers_get_arr_size(ddata);

- stm32_timers_dma_probe(dev, ddata);
+ ret = stm32_timers_dma_probe(dev, ddata);
+ if (ret) {
+ stm32_timers_dma_remove(dev, ddata);
+ return ret;
+ }

platform_set_drvdata(pdev, ddata);

--
Peter
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

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