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spi: rspi: Extract rspi_request_dma_chan()

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Setup of the receive and transmit DMA channels is very similar, so let's
consolidate.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
This commit is contained in:
Geert Uytterhoeven 2014-06-02 15:38:09 +02:00 • committed by Mark Brown
parent 27e105a600
commit 65bf220571
1 changed files with 55 additions and 34 deletions
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89
drivers/spi/spi-rspi.c
View file

@ -942,52 +942,73 @@ static irqreturn_t rspi_irq_tx(int irq, void *_sr)
return 0; return 0;
} }
static struct dma_chan *rspi_request_dma_chan(struct device *dev,
enum dma_transfer_direction dir,
unsigned int id,
dma_addr_t port_addr)
{
dma_cap_mask_t mask;
struct dma_chan *chan;
struct dma_slave_config cfg;
int ret;
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
chan = dma_request_channel(mask, shdma_chan_filter,
(void *)(unsigned long)id);
if (!chan) {
dev_warn(dev, "dma_request_channel failed\n");
return NULL;
}
memset(&cfg, 0, sizeof(cfg));
cfg.slave_id = id;
cfg.direction = dir;
if (dir == DMA_MEM_TO_DEV)
cfg.dst_addr = port_addr;
else
cfg.src_addr = port_addr;
ret = dmaengine_slave_config(chan, &cfg);
if (ret) {
dev_warn(dev, "dmaengine_slave_config failed %d\n", ret);
dma_release_channel(chan);
return NULL;
}
return chan;
}
static int rspi_request_dma(struct rspi_data *rspi, static int rspi_request_dma(struct rspi_data *rspi,
struct platform_device *pdev) struct platform_device *pdev)
{ {
const struct rspi_plat_data *rspi_pd = dev_get_platdata(&pdev->dev); const struct rspi_plat_data *rspi_pd = dev_get_platdata(&pdev->dev);
struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0); struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
dma_cap_mask_t mask;
struct dma_slave_config cfg;
int ret;
if (!res || !rspi_pd) if (!res || !rspi_pd)
return 0; /* The driver assumes no error. */ return 0; /* The driver assumes no error. */
/* If the module receives data by DMAC, it also needs TX DMAC */ /* If the module receives data by DMAC, it also needs TX DMAC */
if (rspi_pd->dma_rx_id && rspi_pd->dma_tx_id) { if (rspi_pd->dma_rx_id && rspi_pd->dma_tx_id) {
dma_cap_zero(mask); rspi->chan_rx = rspi_request_dma_chan(&pdev->dev,
dma_cap_set(DMA_SLAVE, mask); DMA_DEV_TO_MEM,
rspi->chan_rx = dma_request_channel(mask, shdma_chan_filter, rspi_pd->dma_rx_id,
(void *)rspi_pd->dma_rx_id); res->start + RSPI_SPDR);
if (rspi->chan_rx) { if (!rspi->chan_rx)
cfg.slave_id = rspi_pd->dma_rx_id; return -ENODEV;
cfg.direction = DMA_DEV_TO_MEM;
cfg.dst_addr = 0; dev_info(&pdev->dev, "Use DMA when rx.\n");
cfg.src_addr = res->start + RSPI_SPDR;
ret = dmaengine_slave_config(rspi->chan_rx, &cfg);
if (!ret)
dev_info(&pdev->dev, "Use DMA when rx.\n");
else
return ret;
}
} }
if (rspi_pd->dma_tx_id) { if (rspi_pd->dma_tx_id) {
dma_cap_zero(mask); rspi->chan_tx = rspi_request_dma_chan(&pdev->dev,
dma_cap_set(DMA_SLAVE, mask); DMA_MEM_TO_DEV,
rspi->chan_tx = dma_request_channel(mask, shdma_chan_filter, rspi_pd->dma_tx_id,
(void *)rspi_pd->dma_tx_id); res->start + RSPI_SPDR);
if (rspi->chan_tx) { if (!rspi->chan_tx)
cfg.slave_id = rspi_pd->dma_tx_id; return -ENODEV;
cfg.direction = DMA_MEM_TO_DEV;
cfg.dst_addr = res->start + RSPI_SPDR; dev_info(&pdev->dev, "Use DMA when tx\n");
cfg.src_addr = 0;
ret = dmaengine_slave_config(rspi->chan_tx, &cfg);
if (!ret)
dev_info(&pdev->dev, "Use DMA when tx\n");
else
return ret;
}
} }
return 0; return 0;