serial: sh-sci: don't filter on DMA device, use only channel ID

On some sh-mobile systems there are more than one DMA controllers, that
can be used for serial ports. Specifying a DMA device in sh-sci platform
data unnecessarily restricts the driver to only use one DMA controller.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
[Fixed the trivial conflict in include/linux/serial_sci.h]
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/tty/serial/sh-sci.c

@@ -1439,12 +1439,8 @@ static bool filter(struct dma_chan *chan, void *slave)
 	dev_dbg(chan->device->dev, "%s: slave ID %d\n", __func__,
 		param->slave_id);
 
-	if (param->dma_dev == chan->device->dev) {
 	chan->private = param;
 	return true;
-	} else {
-		return false;
-	}
 }
 
 static void rx_timer_fn(unsigned long arg)
@@ -1470,10 +1466,10 @@ static void sci_request_dma(struct uart_port *port)
 	dma_cap_mask_t mask;
 	int nent;
 
-	dev_dbg(port->dev, "%s: port %d DMA %p\n", __func__,
-		port->line, s->cfg->dma_dev);
+	dev_dbg(port->dev, "%s: port %d\n", __func__,
+		port->line);
 
-	if (!s->cfg->dma_dev)
+	if (s->cfg->dma_slave_tx <= 0 || s->cfg->dma_slave_rx <= 0)
 		return;
 
 	dma_cap_zero(mask);
@@ -1483,7 +1479,6 @@ static void sci_request_dma(struct uart_port *port)
 
 	/* Slave ID, e.g., SHDMA_SLAVE_SCIF0_TX */
 	param->slave_id = s->cfg->dma_slave_tx;
-	param->dma_dev = s->cfg->dma_dev;
 
 	s->cookie_tx = -EINVAL;
 	chan = dma_request_channel(mask, filter, param);
@@ -1512,7 +1507,6 @@ static void sci_request_dma(struct uart_port *port)
 
 	/* Slave ID, e.g., SHDMA_SLAVE_SCIF0_RX */
 	param->slave_id = s->cfg->dma_slave_rx;
-	param->dma_dev = s->cfg->dma_dev;
 
 	chan = dma_request_channel(mask, filter, param);
 	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
@@ -1557,9 +1551,6 @@ static void sci_free_dma(struct uart_port *port)
 {
 	struct sci_port *s = to_sci_port(port);
 
-	if (!s->cfg->dma_dev)
-		return;
-
 	if (s->chan_tx)
 		sci_tx_dma_release(s, false);
 	if (s->chan_rx)
@@ -1967,9 +1958,9 @@ static int __devinit sci_init_single(struct platform_device *dev,
 	port->serial_in		= sci_serial_in;
 	port->serial_out	= sci_serial_out;
 
-	if (p->dma_dev)
-		dev_dbg(port->dev, "DMA device %p, tx %d, rx %d\n",
-			p->dma_dev, p->dma_slave_tx, p->dma_slave_rx);
+	if (p->dma_slave_tx > 0 && p->dma_slave_rx > 0)
+		dev_dbg(port->dev, "DMA tx %d, rx %d\n",
+			p->dma_slave_tx, p->dma_slave_rx);
 
 	return 0;
 }

include/linux/serial_sci.h

@@ -131,8 +131,6 @@ struct plat_sci_port {
 
 	struct plat_sci_port_ops	*ops;
 
-	struct device	*dma_dev;
-
 	unsigned int	dma_slave_tx;
 	unsigned int	dma_slave_rx;
 };