[PATCH v2 2/2] spi: sh-msiof: Use correct device for DMA mapping with IOMMU

[Geert Uytterhoeven <geert+renesas@glider.be>]

To function correctly in the presence of an IOMMU, the DMA buffers must be
mapped using the DMA channel's device instead of the MSIOF platform
device's device.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
v2:
  - Use "dma_chan.device->dev" instead of "dma_chan.dev->device",
  - Also fix calls to dma_unmap_single(), dma_mapping_error(), and
    dma_sync_single_for_*()".
---
 drivers/spi/spi-sh-msiof.c | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c
index 9922ed3a4441..6f449b24704a 100644
--- a/drivers/spi/spi-sh-msiof.c
+++ b/drivers/spi/spi-sh-msiof.c
@@ -644,8 +644,8 @@ static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx,
 
 	if (tx) {
 		ier_bits |= IER_TDREQE | IER_TDMAE;
-		dma_sync_single_for_device(&p->pdev->dev, p->tx_dma_addr, len,
-					   DMA_TO_DEVICE);
+		dma_sync_single_for_device(p->master->dma_tx->device->dev,
+					   p->tx_dma_addr, len, DMA_TO_DEVICE);
 		desc_tx = dmaengine_prep_slave_single(p->master->dma_tx,
 					p->tx_dma_addr, len, DMA_TO_DEVICE,
 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
@@ -716,7 +716,8 @@ static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx,
 	}
 
 	if (rx)
-		dma_sync_single_for_cpu(&p->pdev->dev, p->rx_dma_addr, len,
+		dma_sync_single_for_cpu(p->master->dma_rx->device->dev,
+					p->rx_dma_addr, len,
 					DMA_FROM_DEVICE);
 
 	return 0;
@@ -996,6 +997,7 @@ static int sh_msiof_request_dma(struct sh_msiof_spi_priv *p)
 	const struct sh_msiof_spi_info *info = dev_get_platdata(dev);
 	const struct resource *res;
 	struct spi_master *master;
+	struct device *tx_dev, *rx_dev;
 
 	if (!info || !info->dma_tx_id || !info->dma_rx_id)
 		return 0;	/* The driver assumes no error */
@@ -1026,21 +1028,23 @@ static int sh_msiof_request_dma(struct sh_msiof_spi_priv *p)
 	if (!p->rx_dma_page)
 		goto free_tx_page;
 
-	p->tx_dma_addr = dma_map_single(dev, p->tx_dma_page, PAGE_SIZE,
+	tx_dev = master->dma_tx->device->dev;
+	p->tx_dma_addr = dma_map_single(tx_dev, p->tx_dma_page, PAGE_SIZE,
 					DMA_TO_DEVICE);
-	if (dma_mapping_error(dev, p->tx_dma_addr))
+	if (dma_mapping_error(tx_dev, p->tx_dma_addr))
 		goto free_rx_page;
 
-	p->rx_dma_addr = dma_map_single(dev, p->rx_dma_page, PAGE_SIZE,
+	rx_dev = master->dma_rx->device->dev;
+	p->rx_dma_addr = dma_map_single(rx_dev, p->rx_dma_page, PAGE_SIZE,
 					DMA_FROM_DEVICE);
-	if (dma_mapping_error(dev, p->rx_dma_addr))
+	if (dma_mapping_error(rx_dev, p->rx_dma_addr))
 		goto unmap_tx_page;
 
 	dev_info(dev, "DMA available");
 	return 0;
 
 unmap_tx_page:
-	dma_unmap_single(dev, p->tx_dma_addr, PAGE_SIZE, DMA_TO_DEVICE);
+	dma_unmap_single(tx_dev, p->tx_dma_addr, PAGE_SIZE, DMA_TO_DEVICE);
 free_rx_page:
 	free_page((unsigned long)p->rx_dma_page);
 free_tx_page:
@@ -1062,8 +1066,10 @@ static void sh_msiof_release_dma(struct sh_msiof_spi_priv *p)
 		return;
 
 	dev = &p->pdev->dev;
-	dma_unmap_single(dev, p->rx_dma_addr, PAGE_SIZE, DMA_FROM_DEVICE);
-	dma_unmap_single(dev, p->tx_dma_addr, PAGE_SIZE, DMA_TO_DEVICE);
+	dma_unmap_single(master->dma_rx->device->dev, p->rx_dma_addr,
+			 PAGE_SIZE, DMA_FROM_DEVICE);
+	dma_unmap_single(master->dma_tx->device->dev, p->tx_dma_addr,
+			 PAGE_SIZE, DMA_TO_DEVICE);
 	free_page((unsigned long)p->rx_dma_page);
 	free_page((unsigned long)p->tx_dma_page);
 	dma_release_channel(master->dma_rx);
-- 
1.9.1