[PATCH 7/8] serial: xilinx_uartps: get clock rate info from dts

[Josh Cartwright]

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.cartwri...@ni.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 bb3085c..5fb763f 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 0>;
                };
 
                slcr: slcr@f8000000 {
diff --git a/drivers/tty/serial/xilinx_uartps.c 
b/drivers/tty/serial/xilinx_uartps.c
index 23efe17..adfecbc 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 __devinit 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 __devinit 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 __devinit xuartps_probe(struct 
platform_device *pdev)
 static int __devexit 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;
 }
 
-- 
1.8.0


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/