[RFC PATCH 10/13] spi: omap2-mcspi: dma_request_slave_channel() support for DT platforms
From: Matt Porter <hidden>
Date: 2012-09-20 14:42:42
Also in:
linux-arm-kernel, linux-mmc, linux-omap, linux-spi, lkml
Subsystem:
spi subsystem, the rest · Maintainers:
Mark Brown, Linus Torvalds
For platforms with DT populated, use dma_request_slave_channel() to acquire the DMA channel. For !DT platforms, we fall back to explicitly passing the omap_dma_filter_fn() to dma_request_channel(). Once all platforms boot from DT, the dma_request_channel() path can be dropped. Signed-off-by: Matt Porter <redacted> --- drivers/spi/spi-omap2-mcspi.c | 68 +++++++++++++++++++++++++++++------------ 1 file changed, 48 insertions(+), 20 deletions(-)
diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index 9502566..1cf1072 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c@@ -104,6 +104,9 @@ struct omap2_mcspi_dma { struct completion dma_tx_completion; struct completion dma_rx_completion; + + char dma_rx_ch_name[14]; + char dma_tx_ch_name[14]; }; /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
@@ -798,14 +801,26 @@ static int omap2_mcspi_request_dma(struct spi_device *spi) dma_cap_zero(mask); dma_cap_set(DMA_SLAVE, mask); sig = mcspi_dma->dma_rx_sync_dev; - mcspi_dma->dma_rx = dma_request_channel(mask, omap_dma_filter_fn, &sig); + if (spi->dev.of_node) + mcspi_dma->dma_rx = + dma_request_slave_channel(&master->dev, + mcspi_dma->dma_rx_ch_name); + else + mcspi_dma->dma_rx = + dma_request_channel(mask, omap_dma_filter_fn, &sig); if (!mcspi_dma->dma_rx) { dev_err(&spi->dev, "no RX DMA engine channel for McSPI\n"); return -EAGAIN; } sig = mcspi_dma->dma_tx_sync_dev; - mcspi_dma->dma_tx = dma_request_channel(mask, omap_dma_filter_fn, &sig); + if (spi->dev.of_node) + mcspi_dma->dma_tx = + dma_request_slave_channel(&master->dev, + mcspi_dma->dma_tx_ch_name); + else + mcspi_dma->dma_tx = + dma_request_channel(mask, omap_dma_filter_fn, &sig); if (!mcspi_dma->dma_tx) { dev_err(&spi->dev, "no TX DMA engine channel for McSPI\n"); dma_release_channel(mcspi_dma->dma_rx);
@@ -1194,29 +1209,42 @@ static int __devinit omap2_mcspi_probe(struct platform_device *pdev) goto free_master; for (i = 0; i < master->num_chipselect; i++) { - char dma_ch_name[14]; + 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_ch_name, "rx%d", i); - dma_res = platform_get_resource_byname(pdev, IORESOURCE_DMA, - dma_ch_name); - if (!dma_res) { - dev_dbg(&pdev->dev, "cannot get DMA RX channel\n"); - status = -ENODEV; - break; - } + 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_ch_name, "tx%d", i); - dma_res = platform_get_resource_byname(pdev, IORESOURCE_DMA, - dma_ch_name); - if (!dma_res) { - dev_dbg(&pdev->dev, "cannot get DMA TX 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; + mcspi->dma_channels[i].dma_tx_sync_dev = + dma_res->start; + } } if (status < 0)
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1.7.9.5
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