i2c: stm32f7: report dma error during probe

Distinguish between the case where dma information is not provided
within the DT and the case of an error during the dma init.
Exit the probe with error in case of an error during dma init.

Fixes: bb8822cbbc53 ("i2c: i2c-stm32: Add generic DMA API")
Signed-off-by: Alain Volmat <[e-mail]>
Reviewed-by: Pierre-Yves MORDRET <[e-mail]>
Signed-off-by: Wolfram Sang <[e-mail]>

drivers/i2c/busses/i2c-stm32.c

···
 
 	dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
 	if (!dma)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	/* Request and configure I2C TX dma channel */
-	dma->chan_tx = dma_request_slave_channel(dev, "tx");
-	if (!dma->chan_tx) {
+	dma->chan_tx = dma_request_chan(dev, "tx");
+	if (IS_ERR(dma->chan_tx)) {
 		dev_dbg(dev, "can't request DMA tx channel\n");
-		ret = -EINVAL;
+		ret = PTR_ERR(dma->chan_tx);
 		goto fail_al;
 	}
 
···
 	}
 
 	/* Request and configure I2C RX dma channel */
-	dma->chan_rx = dma_request_slave_channel(dev, "rx");
-	if (!dma->chan_rx) {
+	dma->chan_rx = dma_request_chan(dev, "rx");
+	if (IS_ERR(dma->chan_rx)) {
 		dev_err(dev, "can't request DMA rx channel\n");
-		ret = -EINVAL;
+		ret = PTR_ERR(dma->chan_rx);
 		goto fail_tx;
 	}
 
···
 	devm_kfree(dev, dma);
 	dev_info(dev, "can't use DMA\n");
 
-	return NULL;
+	return ERR_PTR(ret);
 }
 
 void stm32_i2c_dma_free(struct stm32_i2c_dma *dma)

drivers/i2c/busses/i2c-stm32f7.c

···
 	i2c_dev->dma = stm32_i2c_dma_request(i2c_dev->dev, phy_addr,
 					     STM32F7_I2C_TXDR,
 					     STM32F7_I2C_RXDR);
+	if (PTR_ERR(i2c_dev->dma) == -ENODEV)
+		i2c_dev->dma = NULL;
+	else if (IS_ERR(i2c_dev->dma)) {
+		ret = PTR_ERR(i2c_dev->dma);
+		if (ret != -EPROBE_DEFER)
+			dev_err(&pdev->dev,
+				"Failed to request dma error %i\n", ret);
+		goto clk_free;
+	}
 
 	platform_set_drvdata(pdev, i2c_dev);