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Commit 727f9c2d authored by Ludovic Desroches's avatar Ludovic Desroches Committed by Wolfram Sang
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i2c: at91: enable probe deferring on dma channel request 



If dma controller is not probed, defer i2c probe.

Signed-off-by: default avatarLudovic Desroches <ludovic.desroches@atmel.com>
Reviewed-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent dc6df6e9

drivers/i2c/busses/i2c-at91.c

+14 −11
Original line number Diff line number Diff line
@@ -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",