[PATCH v5] serial: samsung: use dma_ops of DMA if attached

---
Changes since v1:
1. Rebased the patch on "tty-next" branch of TTY driver tree

Changes since v2:
1. Updated the commit message.
2. Changed the comment description

Changes since v3:
1. Removed the null pointer check for "dma", "dma->tx_chan" and
"dma->rx_chan" and instead sending DMA device pointer while calling
DMA API.

Changes since v4:
1. Fixed the alignments of arguments.

  drivers/tty/serial/samsung_tty.c | 46 +++++++++++++++++---------------
  1 file changed, 25 insertions(+), 21 deletions(-)

diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index 9fbc61151c2e..0cf4dfe77c32 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c

@@ -305,8 +305,9 @@ static void s3c24xx_serial_stop_tx(struct uart_port *port)
  		dmaengine_pause(dma->tx_chan);
  		dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
  		dmaengine_terminate_all(dma->tx_chan);
-		dma_sync_single_for_cpu(ourport->port.dev,
-			dma->tx_transfer_addr, dma->tx_size, DMA_TO_DEVICE);
+		dma_sync_single_for_cpu(dma->tx_chan->device->dev,
+					dma->tx_transfer_addr, dma->tx_size,
+					DMA_TO_DEVICE);
  		async_tx_ack(dma->tx_desc);
  		count = dma->tx_bytes_requested - state.residue;
  		xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);

@@ -338,8 +339,9 @@ static void s3c24xx_serial_tx_dma_complete(void *args)
  	count = dma->tx_bytes_requested - state.residue;
  	async_tx_ack(dma->tx_desc);
  
-	dma_sync_single_for_cpu(ourport->port.dev, dma->tx_transfer_addr,
-				dma->tx_size, DMA_TO_DEVICE);
+	dma_sync_single_for_cpu(dma->tx_chan->device->dev,
+				dma->tx_transfer_addr, dma->tx_size,
+				DMA_TO_DEVICE);
  
  	spin_lock_irqsave(&port->lock, flags);
  

@@ -443,8 +445,9 @@ static int s3c24xx_serial_start_tx_dma(struct s3c24xx_uart_port *ourport,
  	dma->tx_size = count & ~(dma_get_cache_alignment() - 1);
  	dma->tx_transfer_addr = dma->tx_addr + xmit->tail;
  
-	dma_sync_single_for_device(ourport->port.dev, dma->tx_transfer_addr,
-				dma->tx_size, DMA_TO_DEVICE);
+	dma_sync_single_for_device(dma->tx_chan->device->dev,
+				   dma->tx_transfer_addr, dma->tx_size,
+				   DMA_TO_DEVICE);
  
  	dma->tx_desc = dmaengine_prep_slave_single(dma->tx_chan,
  				dma->tx_transfer_addr, dma->tx_size,

@@ -515,7 +518,7 @@ static void s3c24xx_uart_copy_rx_to_tty(struct s3c24xx_uart_port *ourport,
  	if (!count)
  		return;
  
-	dma_sync_single_for_cpu(ourport->port.dev, dma->rx_addr,
+	dma_sync_single_for_cpu(dma->rx_chan->device->dev, dma->rx_addr,
  				dma->rx_size, DMA_FROM_DEVICE);
  
  	ourport->port.icount.rx += count;

@@ -636,8 +639,8 @@ static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport)
  {
  	struct s3c24xx_uart_dma *dma = ourport->dma;
  
-	dma_sync_single_for_device(ourport->port.dev, dma->rx_addr,
-				dma->rx_size, DMA_FROM_DEVICE);
+	dma_sync_single_for_device(dma->rx_chan->device->dev, dma->rx_addr,
+				   dma->rx_size, DMA_FROM_DEVICE);
  
  	dma->rx_desc = dmaengine_prep_slave_single(dma->rx_chan,
  				dma->rx_addr, dma->rx_size, DMA_DEV_TO_MEM,

@@ -1102,18 +1105,19 @@ static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p)
  		goto err_release_tx;
  	}
  
-	dma->rx_addr = dma_map_single(p->port.dev, dma->rx_buf,
-				dma->rx_size, DMA_FROM_DEVICE);
-	if (dma_mapping_error(p->port.dev, dma->rx_addr)) {
+	dma->rx_addr = dma_map_single(dma->rx_chan->device->dev, dma->rx_buf,
+				      dma->rx_size, DMA_FROM_DEVICE);
+	if (dma_mapping_error(dma->rx_chan->device->dev, dma->rx_addr)) {
  		reason = "DMA mapping error for RX buffer";
  		ret = -EIO;
  		goto err_free_rx;
  	}
  
  	/* TX buffer */
-	dma->tx_addr = dma_map_single(p->port.dev, p->port.state->xmit.buf,
-				UART_XMIT_SIZE, DMA_TO_DEVICE);
-	if (dma_mapping_error(p->port.dev, dma->tx_addr)) {
+	dma->tx_addr = dma_map_single(dma->tx_chan->device->dev,
+				      p->port.state->xmit.buf, UART_XMIT_SIZE,
+				      DMA_TO_DEVICE);
+	if (dma_mapping_error(dma->tx_chan->device->dev, dma->tx_addr)) {
  		reason = "DMA mapping error for TX buffer";
  		ret = -EIO;
  		goto err_unmap_rx;

@@ -1122,8 +1126,8 @@ static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p)
  	return 0;
  
  err_unmap_rx:
-	dma_unmap_single(p->port.dev, dma->rx_addr, dma->rx_size,
-			 DMA_FROM_DEVICE);
+	dma_unmap_single(dma->rx_chan->device->dev, dma->rx_addr,
+			 dma->rx_size, DMA_FROM_DEVICE);
  err_free_rx:
  	kfree(dma->rx_buf);
  err_release_tx:

@@ -1142,8 +1146,8 @@ static void s3c24xx_serial_release_dma(struct s3c24xx_uart_port *p)
  
  	if (dma->rx_chan) {
  		dmaengine_terminate_all(dma->rx_chan);
-		dma_unmap_single(p->port.dev, dma->rx_addr,
-				dma->rx_size, DMA_FROM_DEVICE);
+		dma_unmap_single(dma->rx_chan->device->dev, dma->rx_addr,
+				 dma->rx_size, DMA_FROM_DEVICE);
  		kfree(dma->rx_buf);
  		dma_release_channel(dma->rx_chan);
  		dma->rx_chan = NULL;

@@ -1151,8 +1155,8 @@ static void s3c24xx_serial_release_dma(struct s3c24xx_uart_port *p)
  
  	if (dma->tx_chan) {
  		dmaengine_terminate_all(dma->tx_chan);
-		dma_unmap_single(p->port.dev, dma->tx_addr,
-				UART_XMIT_SIZE, DMA_TO_DEVICE);
+		dma_unmap_single(dma->tx_chan->device->dev, dma->tx_addr,
+				 UART_XMIT_SIZE, DMA_TO_DEVICE);
  		dma_release_channel(dma->tx_chan);
  		dma->tx_chan = NULL;
  	}