i2c: stm32: fix the device used for the DMA map

commit c870cbb upstream.

If the DMA mapping failed, it produced an error log with the wrong
device name:
"stm32-dma3 40400000.dma-controller: rejecting DMA map of vmalloc memory"
Fix this issue by replacing the dev with the I2C dev.

Fixes: bb8822c ("i2c: i2c-stm32: Add generic DMA API")
Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com>
Cc: <stable@vger.kernel.org> # v4.18+
Acked-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20250704-i2c-upstream-v4-1-84a095a2c728@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Upsylonbare

drivers/i2c/busses/i2c-stm32.c

@@ -102,7 +102,6 @@ int stm32_i2c_prep_dma_xfer(struct device *dev, struct stm32_i2c_dma *dma,
 			    void *dma_async_param)
 {
 	struct dma_async_tx_descriptor *txdesc;
-	struct device *chan_dev;
 	int ret;
 
 	if (rd_wr) {
@@ -116,11 +115,10 @@ int stm32_i2c_prep_dma_xfer(struct device *dev, struct stm32_i2c_dma *dma,
 	}
 
 	dma->dma_len = len;
-	chan_dev = dma->chan_using->device->dev;
 
-	dma->dma_buf = dma_map_single(chan_dev, buf, dma->dma_len,
+	dma->dma_buf = dma_map_single(dev, buf, dma->dma_len,
 				      dma->dma_data_dir);
-	if (dma_mapping_error(chan_dev, dma->dma_buf)) {
+	if (dma_mapping_error(dev, dma->dma_buf)) {
 		dev_err(dev, "DMA mapping failed\n");
 		return -EINVAL;
 	}
@@ -150,7 +148,7 @@ int stm32_i2c_prep_dma_xfer(struct device *dev, struct stm32_i2c_dma *dma,
 	return 0;
 
 err:
-	dma_unmap_single(chan_dev, dma->dma_buf, dma->dma_len,
+	dma_unmap_single(dev, dma->dma_buf, dma->dma_len,
 			 dma->dma_data_dir);
 	return ret;
 }

drivers/i2c/busses/i2c-stm32f7.c

@@ -741,10 +741,10 @@ static void stm32f7_i2c_dma_callback(void *arg)
 {
 	struct stm32f7_i2c_dev *i2c_dev = (struct stm32f7_i2c_dev *)arg;
 	struct stm32_i2c_dma *dma = i2c_dev->dma;
-	struct device *dev = dma->chan_using->device->dev;
 
 	stm32f7_i2c_disable_dma_req(i2c_dev);
-	dma_unmap_single(dev, dma->dma_buf, dma->dma_len, dma->dma_data_dir);
+	dma_unmap_single(i2c_dev->dev, dma->dma_buf, dma->dma_len,
+			 dma->dma_data_dir);
 	complete(&dma->dma_complete);
 }