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i2c: at91: enable probe deferring on dma channel request

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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>
This commit is contained in:
Ludovic Desroches 2014-11-21 14:44:32 +01:00 committed by Wolfram Sang
parent dc6df6e90d
commit 727f9c2dad
1 changed files with 14 additions and 11 deletions
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25
drivers/i2c/busses/i2c-at91.c
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@ -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",