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| author | Ludovic Desroches <ludovic.desroches@atmel.com> | 2014-11-21 14:44:32 +0100 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2014-11-23 17:27:29 +0100 |
| commit | 727f9c2dad9dd3e9aff4f64e92df577f1409a768 (patch) | |
| tree | 408e4801ba7fe270c9ad7efbaa11895d5514aace /drivers/i2c/busses | |
| parent | dc6df6e90de9b1e0fb2e2329312b4431de60ad0f (diff) | |
| download | linux-727f9c2dad9dd3e9aff4f64e92df577f1409a768.tar.gz linux-727f9c2dad9dd3e9aff4f64e92df577f1409a768.tar.bz2 linux-727f9c2dad9dd3e9aff4f64e92df577f1409a768.zip | |
i2c: at91: enable probe deferring on dma channel request
If dma controller is not probed, defer i2c probe.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c/busses')
| -rw-r--r-- | drivers/i2c/busses/i2c-at91.c | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c index 8790f2332458..87e2f142ae6c 100644 --- a/drivers/i2c/busses/i2c-at91.c +++ b/drivers/i2c/busses/i2c-at91.c @@ -650,17 +650,17 @@ static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr) slave_config.dst_maxburst = 1; slave_config.device_fc = false; - dma->chan_tx = dma_request_slave_channel(dev->dev, "tx"); - if (!dma->chan_tx) { - dev_err(dev->dev, "can't get a DMA channel for tx\n"); - ret = -EBUSY; + dma->chan_tx = dma_request_slave_channel_reason(dev->dev, "tx"); + if (IS_ERR(dma->chan_tx)) { + ret = PTR_ERR(dma->chan_tx); + dma->chan_tx = NULL; goto error; } - dma->chan_rx = dma_request_slave_channel(dev->dev, "rx"); - if (!dma->chan_rx) { - dev_err(dev->dev, "can't get a DMA channel for rx\n"); - ret = -EBUSY; + dma->chan_rx = dma_request_slave_channel_reason(dev->dev, "rx"); + if (IS_ERR(dma->chan_rx)) { + ret = PTR_ERR(dma->chan_rx); + dma->chan_rx = NULL; goto error; } @@ -681,6 +681,7 @@ static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr) sg_init_table(&dma->sg, 1); dma->buf_mapped = false; dma->xfer_in_progress = false; + dev->use_dma = true; dev_info(dev->dev, "using %s (tx) and %s (rx) for DMA transfers\n", dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx)); @@ -688,7 +689,8 @@ static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr) return ret; error: - dev_info(dev->dev, "can't use DMA\n"); + if (ret != -EPROBE_DEFER) + dev_info(dev->dev, "can't use DMA, error %d\n", ret); if (dma->chan_rx) dma_release_channel(dma->chan_rx); if (dma->chan_tx) @@ -757,8 +759,9 @@ static int at91_twi_probe(struct platform_device *pdev) clk_prepare_enable(dev->clk); if (dev->dev->of_node) { - if (at91_twi_configure_dma(dev, phy_addr) == 0) - dev->use_dma = true; + rc = at91_twi_configure_dma(dev, phy_addr); + if (rc == -EPROBE_DEFER) + return rc; } rc = of_property_read_u32(dev->dev->of_node, "clock-frequency", |