1 files changed, 38 insertions, 26 deletions

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index b2e9e177a354..8ab70a620919 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -267,7 +267,7 @@ static void pl011_sgbuf_free(struct dma_chan *chan, struct pl011_sgbuf *sg,
 	}
 }
 
-static void pl011_dma_probe_initcall(struct uart_amba_port *uap)
+static void pl011_dma_probe_initcall(struct device *dev, struct uart_amba_port *uap)
 {
 	/* DMA is the sole user of the platform data right now */
 	struct amba_pl011_data *plat = uap->port.dev->platform_data;
@@ -281,20 +281,25 @@ static void pl011_dma_probe_initcall(struct uart_amba_port *uap)
 	struct dma_chan *chan;
 	dma_cap_mask_t mask;
 
-	/* We need platform data */
-	if (!plat || !plat->dma_filter) {
-		dev_info(uap->port.dev, "no DMA platform data\n");
-		return;
-	}
+	chan = dma_request_slave_channel(dev, "tx");
 
-	/* Try to acquire a generic DMA engine slave TX channel */
-	dma_cap_zero(mask);
-	dma_cap_set(DMA_SLAVE, mask);
-
-	chan = dma_request_channel(mask, plat->dma_filter, plat->dma_tx_param);
 	if (!chan) {
-		dev_err(uap->port.dev, "no TX DMA channel!\n");
-		return;
+		/* We need platform data */
+		if (!plat || !plat->dma_filter) {
+			dev_info(uap->port.dev, "no DMA platform data\n");
+			return;
+		}
+
+		/* Try to acquire a generic DMA engine slave TX channel */
+		dma_cap_zero(mask);
+		dma_cap_set(DMA_SLAVE, mask);
+
+		chan = dma_request_channel(mask, plat->dma_filter,
+						plat->dma_tx_param);
+		if (!chan) {
+			dev_err(uap->port.dev, "no TX DMA channel!\n");
+			return;
+		}
 	}
 
 	dmaengine_slave_config(chan, &tx_conf);
@@ -304,7 +309,18 @@ static void pl011_dma_probe_initcall(struct uart_amba_port *uap)
 		 dma_chan_name(uap->dmatx.chan));
 
 	/* Optionally make use of an RX channel as well */
-	if (plat->dma_rx_param) {
+	chan = dma_request_slave_channel(dev, "rx");
+	
+	if (!chan && plat->dma_rx_param) {
+		chan = dma_request_channel(mask, plat->dma_filter, plat->dma_rx_param);
+
+		if (!chan) {
+			dev_err(uap->port.dev, "no RX DMA channel!\n");
+			return;
+		}
+	}
+
+	if (chan) {
 		struct dma_slave_config rx_conf = {
 			.src_addr = uap->port.mapbase + UART01x_DR,
 			.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
@@ -313,12 +329,6 @@ static void pl011_dma_probe_initcall(struct uart_amba_port *uap)
 			.device_fc = false,
 		};
 
-		chan = dma_request_channel(mask, plat->dma_filter, plat->dma_rx_param);
-		if (!chan) {
-			dev_err(uap->port.dev, "no RX DMA channel!\n");
-			return;
-		}
-
 		dmaengine_slave_config(chan, &rx_conf);
 		uap->dmarx.chan = chan;
 
@@ -360,6 +370,7 @@ static void pl011_dma_probe_initcall(struct uart_amba_port *uap)
 struct dma_uap {
 	struct list_head node;
 	struct uart_amba_port *uap;
+	struct device *dev;
 };
 
 static LIST_HEAD(pl011_dma_uarts);
@@ -370,7 +381,7 @@ static int __init pl011_dma_initcall(void)
 
 	list_for_each_safe(node, tmp, &pl011_dma_uarts) {
 		struct dma_uap *dmau = list_entry(node, struct dma_uap, node);
-		pl011_dma_probe_initcall(dmau->uap);
+		pl011_dma_probe_initcall(dmau->dev, dmau->uap);
 		list_del(node);
 		kfree(dmau);
 	}
@@ -379,18 +390,19 @@ static int __init pl011_dma_initcall(void)
 
 device_initcall(pl011_dma_initcall);
 
-static void pl011_dma_probe(struct uart_amba_port *uap)
+static void pl011_dma_probe(struct device *dev, struct uart_amba_port *uap)
 {
 	struct dma_uap *dmau = kzalloc(sizeof(struct dma_uap), GFP_KERNEL);
 	if (dmau) {
 		dmau->uap = uap;
+		dmau->dev = dev;
 		list_add_tail(&dmau->node, &pl011_dma_uarts);
 	}
 }
 #else
-static void pl011_dma_probe(struct uart_amba_port *uap)
+static void pl011_dma_probe(struct device *dev, struct uart_amba_port *uap)
 {
-	pl011_dma_probe_initcall(uap);
+	pl011_dma_probe_initcall(dev, uap);
 }
 #endif
 
@@ -1096,7 +1108,7 @@ static inline bool pl011_dma_rx_running(struct uart_amba_port *uap)
 
 #else
 /* Blank functions if the DMA engine is not available */
-static inline void pl011_dma_probe(struct uart_amba_port *uap)
+static inline void pl011_dma_probe(struct device *dev, struct uart_amba_port *uap)
 {
 }
 
@@ -2155,7 +2167,7 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
 	uap->port.ops = &amba_pl011_pops;
 	uap->port.flags = UPF_BOOT_AUTOCONF;
 	uap->port.line = i;
-	pl011_dma_probe(uap);
+	pl011_dma_probe(&dev->dev, uap);
 
 	/* Ensure interrupts from this UART are masked and cleared */
 	writew(0, uap->port.membase + UART011_IMSC);