[PATCH] spi: omap2-mcspi: Use dma_request_chan() for requesting DMA channel

From: Peter Ujfalusi
Date: Fri Apr 29 2016 - 09:11:56 EST


With the new dma_request_chan() the client driver does not need to look for
the DMA resource and it does not need to pass filter_fn anymore.
By switching to the new API the driver can now support deferred probing
against DMA.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
drivers/spi/spi-omap2-mcspi.c | 83 ++++++++++---------------------------------
1 file changed, 18 insertions(+), 65 deletions(-)

diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index 0caa3c8bef46..1d237e93a289 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -23,7 +23,6 @@
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
-#include <linux/omap-dma.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/err.h>
@@ -103,9 +102,6 @@ struct omap2_mcspi_dma {
struct dma_chan *dma_tx;
struct dma_chan *dma_rx;

- int dma_tx_sync_dev;
- int dma_rx_sync_dev;
-
struct completion dma_tx_completion;
struct completion dma_rx_completion;

@@ -964,8 +960,7 @@ static int omap2_mcspi_request_dma(struct spi_device *spi)
struct spi_master *master = spi->master;
struct omap2_mcspi *mcspi;
struct omap2_mcspi_dma *mcspi_dma;
- dma_cap_mask_t mask;
- unsigned sig;
+ int ret = 0;

mcspi = spi_master_get_devdata(master);
mcspi_dma = mcspi->dma_channels + spi->chip_select;
@@ -973,34 +968,25 @@ static int omap2_mcspi_request_dma(struct spi_device *spi)
init_completion(&mcspi_dma->dma_rx_completion);
init_completion(&mcspi_dma->dma_tx_completion);

- dma_cap_zero(mask);
- dma_cap_set(DMA_SLAVE, mask);
- sig = mcspi_dma->dma_rx_sync_dev;
-
- mcspi_dma->dma_rx =
- dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
- &sig, &master->dev,
- mcspi_dma->dma_rx_ch_name);
- if (!mcspi_dma->dma_rx)
+ mcspi_dma->dma_rx = dma_request_chan(&master->dev,
+ mcspi_dma->dma_rx_ch_name);
+ if (IS_ERR(mcspi_dma->dma_rx)) {
+ ret = PTR_ERR(mcspi_dma->dma_rx);
+ mcspi_dma->dma_rx = NULL;
goto no_dma;
+ }

- sig = mcspi_dma->dma_tx_sync_dev;
- mcspi_dma->dma_tx =
- dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
- &sig, &master->dev,
- mcspi_dma->dma_tx_ch_name);
-
- if (!mcspi_dma->dma_tx) {
+ mcspi_dma->dma_tx = dma_request_chan(&master->dev,
+ mcspi_dma->dma_tx_ch_name);
+ if (IS_ERR(mcspi_dma->dma_tx)) {
+ ret = PTR_ERR(mcspi_dma->dma_tx);
+ mcspi_dma->dma_tx = NULL;
dma_release_channel(mcspi_dma->dma_rx);
mcspi_dma->dma_rx = NULL;
- goto no_dma;
}

- return 0;
-
no_dma:
- dev_warn(&spi->dev, "not using DMA for McSPI\n");
- return -EAGAIN;
+ return ret;
}

static int omap2_mcspi_setup(struct spi_device *spi)
@@ -1039,8 +1025,9 @@ static int omap2_mcspi_setup(struct spi_device *spi)

if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx) {
ret = omap2_mcspi_request_dma(spi);
- if (ret < 0 && ret != -EAGAIN)
- return ret;
+ if (ret)
+ dev_warn(&spi->dev, "not using DMA for McSPI (%d)\n",
+ ret);
}

ret = pm_runtime_get_sync(mcspi->dev);
@@ -1434,42 +1421,8 @@ static int omap2_mcspi_probe(struct platform_device *pdev)
}

for (i = 0; i < master->num_chipselect; i++) {
- char *dma_rx_ch_name = mcspi->dma_channels[i].dma_rx_ch_name;
- char *dma_tx_ch_name = mcspi->dma_channels[i].dma_tx_ch_name;
- struct resource *dma_res;
-
- sprintf(dma_rx_ch_name, "rx%d", i);
- if (!pdev->dev.of_node) {
- dma_res =
- platform_get_resource_byname(pdev,
- IORESOURCE_DMA,
- dma_rx_ch_name);
- if (!dma_res) {
- dev_dbg(&pdev->dev,
- "cannot get DMA RX channel\n");
- status = -ENODEV;
- break;
- }
-
- mcspi->dma_channels[i].dma_rx_sync_dev =
- dma_res->start;
- }
- sprintf(dma_tx_ch_name, "tx%d", i);
- if (!pdev->dev.of_node) {
- dma_res =
- platform_get_resource_byname(pdev,
- IORESOURCE_DMA,
- dma_tx_ch_name);
- if (!dma_res) {
- dev_dbg(&pdev->dev,
- "cannot get DMA TX channel\n");
- status = -ENODEV;
- break;
- }
-
- mcspi->dma_channels[i].dma_tx_sync_dev =
- dma_res->start;
- }
+ sprintf(mcspi->dma_channels[i].dma_rx_ch_name, "rx%d", i);
+ sprintf(mcspi->dma_channels[i].dma_tx_ch_name, "tx%d", i);
}

if (status < 0)
--
2.8.1