From b4c582a92f41417154131083127e24b66cc4b31b Mon Sep 17 00:00:00 2001
From: Josh Cartwright <josh.cartwright@ni.com>
Date: Wed, 31 Oct 2012 13:28:49 -0600
Subject: [PATCH] serial: xilinx_uartps: get clock rate info from dts

Add support for specifying clock information for the uart clk via the
device tree.  This eliminates the need to hardcode rates in the device
tree.

Signed-off-by: Josh Cartwright <josh.cartwright@ni.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
---
 arch/arm/boot/dts/zynq-7000.dtsi   |  4 ++--
 drivers/tty/serial/xilinx_uartps.c | 30 +++++++++++++++++-------------
 2 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/arch/arm/boot/dts/zynq-7000.dtsi b/arch/arm/boot/dts/zynq-7000.dtsi
index 401c1262d4ed..5914b5654591 100644
--- a/arch/arm/boot/dts/zynq-7000.dtsi
+++ b/arch/arm/boot/dts/zynq-7000.dtsi
@@ -44,14 +44,14 @@
 			compatible = "xlnx,xuartps";
 			reg = <0xE0000000 0x1000>;
 			interrupts = <0 27 4>;
-			clock = <50000000>;
+			clocks = <&uart_clk 0>;
 		};
 
 		uart1: uart@e0001000 {
 			compatible = "xlnx,xuartps";
 			reg = <0xE0001000 0x1000>;
 			interrupts = <0 50 4>;
-			clock = <50000000>;
+			clocks = <&uart_clk 1>;
 		};
 
 		slcr: slcr@f8000000 {
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index 9ab910370c56..2be22a2a0ea1 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -17,6 +17,7 @@
 #include <linux/tty.h>
 #include <linux/tty_flip.h>
 #include <linux/console.h>
+#include <linux/clk.h>
 #include <linux/irq.h>
 #include <linux/io.h>
 #include <linux/of.h>
@@ -944,18 +945,20 @@ static int xuartps_probe(struct platform_device *pdev)
 	int rc;
 	struct uart_port *port;
 	struct resource *res, *res2;
-	int clk = 0;
+	struct clk *clk;
 
-	const unsigned int *prop;
-
-	prop = of_get_property(pdev->dev.of_node, "clock", NULL);
-	if (prop)
-		clk = be32_to_cpup(prop);
+	clk = of_clk_get(pdev->dev.of_node, 0);
 	if (!clk) {
 		dev_err(&pdev->dev, "no clock specified\n");
 		return -ENODEV;
 	}
 
+	rc = clk_prepare_enable(clk);
+	if (rc) {
+		dev_err(&pdev->dev, "could not enable clock\n");
+		return -EBUSY;
+	}
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res)
 		return -ENODEV;
@@ -978,7 +981,8 @@ static int xuartps_probe(struct platform_device *pdev)
 		port->mapbase = res->start;
 		port->irq = res2->start;
 		port->dev = &pdev->dev;
-		port->uartclk = clk;
+		port->uartclk = clk_get_rate(clk);
+		port->private_data = clk;
 		dev_set_drvdata(&pdev->dev, port);
 		rc = uart_add_one_port(&xuartps_uart_driver, port);
 		if (rc) {
@@ -1000,14 +1004,14 @@ static int xuartps_probe(struct platform_device *pdev)
 static int xuartps_remove(struct platform_device *pdev)
 {
 	struct uart_port *port = dev_get_drvdata(&pdev->dev);
-	int rc = 0;
+	struct clk *clk = port->private_data;
+	int rc;
 
 	/* Remove the xuartps port from the serial core */
-	if (port) {
-		rc = uart_remove_one_port(&xuartps_uart_driver, port);
-		dev_set_drvdata(&pdev->dev, NULL);
-		port->mapbase = 0;
-	}
+	rc = uart_remove_one_port(&xuartps_uart_driver, port);
+	dev_set_drvdata(&pdev->dev, NULL);
+	port->mapbase = 0;
+	clk_disable_unprepare(clk);
 	return rc;
 }
 
-- 
2.39.2