tty: ar933x_uart: use the clk API to get the uart clock

The AR933x UARTs are only used on the Atheros AR933x
SoCs. The base clock frequency of the UART is passed
to the driver via platform data. The SoC support code
implements the generic clock API, and the clock rate
can be retrieved via that.

Update the code to get the clock rate via the generic
clock API instead of using the platform data.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index f13624807d124dfc3ae466a6ce5409be227f4d44..3c598e3e7156a98104fd26d5add327aa1bc5dd6b 100644 (file)
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1402,7 +1402,7 @@ config SERIAL_XILINX_PS_UART_CONSOLE
 
 config SERIAL_AR933X
        bool "AR933X serial port support"
-       depends on SOC_AR933X
+       depends on HAVE_CLK && SOC_AR933X
        select SERIAL_CORE
        help
          If you have an Atheros AR933X SOC based board and want to use the

diff --git a/drivers/tty/serial/ar933x_uart.c b/drivers/tty/serial/ar933x_uart.c
index 78be13ac1a957d673905efe995884b5dc5ad926c..1052ee0383e02b71dd1b72b7452f86e36a0f0d4d 100644 (file)
--- a/drivers/tty/serial/ar933x_uart.c
+++ b/drivers/tty/serial/ar933x_uart.c
@@ -24,11 +24,11 @@
 #include <linux/slab.h>
 #include <linux/io.h>
 #include <linux/irq.h>
+#include <linux/clk.h>
 
 #include <asm/div64.h>
 
 #include <asm/mach-ath79/ar933x_uart.h>
-#include <asm/mach-ath79/ar933x_uart_platform.h>
 
 #define DRIVER_NAME "ar933x-uart"
 
@@ -47,6 +47,7 @@ struct ar933x_uart_port {
        unsigned int            ier;    /* shadow Interrupt Enable Register */
        unsigned int            min_baud;
        unsigned int            max_baud;
+       struct clk              *clk;
 };
 
 static inline unsigned int ar933x_uart_read(struct ar933x_uart_port *up,
@@ -622,7 +623,6 @@ static struct uart_driver ar933x_uart_driver = {
 
 static int ar933x_uart_probe(struct platform_device *pdev)
 {
-       struct ar933x_uart_platform_data *pdata;
        struct ar933x_uart_port *up;
        struct uart_port *port;
        struct resource *mem_res;
@@ -631,10 +631,6 @@ static int ar933x_uart_probe(struct platform_device *pdev)
        int id;
        int ret;
 
-       pdata = dev_get_platdata(&pdev->dev);
-       if (!pdata)
-               return -EINVAL;
-
        id = pdev->id;
        if (id == -1)
                id = 0;
@@ -653,6 +649,12 @@ static int ar933x_uart_probe(struct platform_device *pdev)
        if (!up)
                return -ENOMEM;
 
+       up->clk = devm_clk_get(&pdev->dev, "uart");
+       if (IS_ERR(up->clk)) {
+               dev_err(&pdev->dev, "unable to get UART clock\n");
+               return PTR_ERR(up->clk);
+       }
+
        port = &up->port;
 
        mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -660,13 +662,22 @@ static int ar933x_uart_probe(struct platform_device *pdev)
        if (IS_ERR(port->membase))
                return PTR_ERR(port->membase);
 
+       ret = clk_prepare_enable(up->clk);
+       if (ret)
+               return ret;
+
+       port->uartclk = clk_get_rate(up->clk);
+       if (!port->uartclk) {
+               ret = -EINVAL;
+               goto err_disable_clk;
+       }
+
        port->mapbase = mem_res->start;
        port->line = id;
        port->irq = irq_res->start;
        port->dev = &pdev->dev;
        port->type = PORT_AR933X;
        port->iotype = UPIO_MEM32;
-       port->uartclk = pdata->uartclk;
 
        port->regshift = 2;
        port->fifosize = AR933X_UART_FIFO_SIZE;
@@ -682,10 +693,14 @@ static int ar933x_uart_probe(struct platform_device *pdev)
 
        ret = uart_add_one_port(&ar933x_uart_driver, &up->port);
        if (ret)
-               return ret;
+               goto err_disable_clk;
 
        platform_set_drvdata(pdev, up);
        return 0;
+
+err_disable_clk:
+       clk_disable_unprepare(up->clk);
+       return ret;
 }
 
 static int ar933x_uart_remove(struct platform_device *pdev)
@@ -694,8 +709,10 @@ static int ar933x_uart_remove(struct platform_device *pdev)
 
        up = platform_get_drvdata(pdev);
 
-       if (up)
+       if (up) {
                uart_remove_one_port(&ar933x_uart_driver, &up->port);
+               clk_disable_unprepare(up->clk);
+       }
 
        return 0;
 }