[PATCH v2 4/5] serial: xilinx_uartps: get clock rate info from dts
From: Josh Cartwright <hidden>
Date: 2012-11-08 19:54:17
Also in:
linux-serial, lkml
Subsystem:
the rest, tty layer and serial drivers · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
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 <redacted> --- 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..c975c2d 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 at e0001000 { compatible = "xlnx,xuartps"; reg = <0xE0001000 0x1000>; interrupts = <0 50 4>; - clock = <50000000>; + clocks = <&uart_clk 1>; }; slcr: slcr at 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