Re: [PATCH 1/2] spi: atmel: convert to dma_request_slave_channel_compat()

From: Yang Wenyou
Date: Mon Jun 03 2013 - 22:49:24 EST


Richard Genoud wrote:
Use generic DMA DT helper.
Platforms booting with or without DT populated are both supported.

Based on Ludovic Desroches <ludovic.desroches@xxxxxxxxx> patchset
"ARM: at91: move to generic DMA device tree binding"

Signed-off-by: Richard Genoud <richard.genoud@xxxxxxxxx>
---
drivers/spi/spi-atmel.c | 42 +++++++++++++++++++++++++++---------------
1 file changed, 27 insertions(+), 15 deletions(-)

rebased on linux-next next-20130531
Tested on at91sam9g25ek,
Based on linux-next, next-20130603
plus Ludovic Desroches' patch "ARM: at91: dt: add header to define at_hdmac configuration"

Tested-by: Wenyou Yang<wenyou.yang@xxxxxxxxx>
diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index 31cfc87..ea1ec00 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -424,10 +424,15 @@ static int atmel_spi_dma_slave_config(struct atmel_spi *as,
return err;
}
-static bool filter(struct dma_chan *chan, void *slave)
+static bool filter(struct dma_chan *chan, void *pdata)
{
- struct at_dma_slave *sl = slave;
+ struct atmel_spi_dma *sl_pdata = pdata;
+ struct at_dma_slave *sl;
+ if (!sl_pdata)
+ return false;
+
+ sl = &sl_pdata->dma_slave;
if (sl->dma_dev == chan->device->dev) {
chan->private = sl;
return true;
@@ -438,24 +443,31 @@ static bool filter(struct dma_chan *chan, void *slave)
static int atmel_spi_configure_dma(struct atmel_spi *as)
{
- struct at_dma_slave *sdata = &as->dma.dma_slave;
struct dma_slave_config slave_config;
+ struct device *dev = &as->pdev->dev;
int err;
- if (sdata && sdata->dma_dev) {
- dma_cap_mask_t mask;
+ dma_cap_mask_t mask;
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
- /* Try to grab two DMA channels */
- dma_cap_zero(mask);
- dma_cap_set(DMA_SLAVE, mask);
- as->dma.chan_tx = dma_request_channel(mask, filter, sdata);
- if (as->dma.chan_tx)
- as->dma.chan_rx =
- dma_request_channel(mask, filter, sdata);
+ as->dma.chan_tx = dma_request_slave_channel_compat(mask, filter,
+ &as->dma,
+ dev, "tx");
+ if (!as->dma.chan_tx) {
+ dev_err(dev,
+ "DMA TX channel not available, SPI unable to use DMA\n");
+ err = -EBUSY;
+ goto error;
}
- if (!as->dma.chan_rx || !as->dma.chan_tx) {
- dev_err(&as->pdev->dev,
- "DMA channel not available, SPI unable to use DMA\n");
+
+ as->dma.chan_rx = dma_request_slave_channel_compat(mask, filter,
+ &as->dma,
+ dev, "rx");
+
+ if (!as->dma.chan_rx) {
+ dev_err(dev,
+ "DMA RX channel not available, SPI unable to use DMA\n");
err = -EBUSY;
goto error;
}

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