serial: 8250_dw: Let ACPI code extract the DMA client info

The new ACPI DMA helpers in dmaengine API can take care of
extracting all the necessary information regarding DMA. The
driver does not need to do this separately any more.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250_dw.c

@@ -163,66 +163,10 @@ static int dw8250_probe_of(struct uart_port *p)
 }
 
 #ifdef CONFIG_ACPI
-static bool dw8250_acpi_dma_filter(struct dma_chan *chan, void *parm)
-{
-	return chan->chan_id == *(int *)parm;
-}
-
-static acpi_status
-dw8250_acpi_walk_resource(struct acpi_resource *res, void *data)
-{
-	struct uart_port		*p = data;
-	struct uart_8250_port		*port;
-	struct uart_8250_dma		*dma;
-	struct acpi_resource_fixed_dma	*fixed_dma;
-	struct dma_slave_config		*slave;
-
-	port = container_of(p, struct uart_8250_port, port);
-
-	switch (res->type) {
-	case ACPI_RESOURCE_TYPE_FIXED_DMA:
-		fixed_dma = &res->data.fixed_dma;
-
-		/* TX comes first */
-		if (!port->dma) {
-			dma = devm_kzalloc(p->dev, sizeof(*dma), GFP_KERNEL);
-			if (!dma)
-				return AE_NO_MEMORY;
-
-			port->dma = dma;
-			slave = &dma->txconf;
-
-			slave->direction	= DMA_MEM_TO_DEV;
-			slave->dst_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
-			slave->slave_id		= fixed_dma->request_lines;
-			slave->dst_maxburst	= port->tx_loadsz / 4;
-
-			dma->tx_chan_id		= fixed_dma->channels;
-			dma->tx_param		= &dma->tx_chan_id;
-			dma->fn			= dw8250_acpi_dma_filter;
-		} else {
-			dma = port->dma;
-			slave = &dma->rxconf;
-
-			slave->direction	= DMA_DEV_TO_MEM;
-			slave->src_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
-			slave->slave_id		= fixed_dma->request_lines;
-			slave->src_maxburst	= p->fifosize / 4;
-
-			dma->rx_chan_id		= fixed_dma->channels;
-			dma->rx_param		= &dma->rx_chan_id;
-		}
-
-		break;
-	}
-
-	return AE_OK;
-}
-
-static int dw8250_probe_acpi(struct uart_port *p)
+static int dw8250_probe_acpi(struct uart_8250_port *up)
 {
 	const struct acpi_device_id *id;
-	acpi_status status;
+	struct uart_port *p = &up->port;
 
 	id = acpi_match_device(p->dev->driver->acpi_match_table, p->dev);
 	if (!id)
@@ -236,13 +180,12 @@ static int dw8250_probe_acpi(struct uart_port *p)
 	if (!p->uartclk)
 		p->uartclk = (unsigned int)id->driver_data;
 
-	status = acpi_walk_resources(ACPI_HANDLE(p->dev), METHOD_NAME__CRS,
-				     dw8250_acpi_walk_resource, p);
-	if (ACPI_FAILURE(status)) {
-		dev_err_ratelimited(p->dev, "%s failed \"%s\"\n", __func__,
-				    acpi_format_exception(status));
-		return -ENODEV;
-	}
+	up->dma = devm_kzalloc(p->dev, sizeof(*up->dma), GFP_KERNEL);
+	if (!up->dma)
+		return -ENOMEM;
+
+	up->dma->rxconf.src_maxburst = p->fifosize / 4;
+	up->dma->txconf.dst_maxburst = p->fifosize / 4;
 
 	return 0;
 }
@@ -329,7 +272,7 @@ static int dw8250_probe(struct platform_device *pdev)
 		if (err)
 			return err;
 	} else if (ACPI_HANDLE(&pdev->dev)) {
-		err = dw8250_probe_acpi(&uart.port);
+		err = dw8250_probe_acpi(&uart);
 		if (err)
 			return err;
 	} else {