ARM: davinci: serial: provide API to initialze UART clocks

Provide an API to initialize a UART clock. Refactor existing
davinci_serial_init() to separate out the part which enables
the clock.

This will later be used to help DA850 DT boot support.

Signed-off-by: Sekhar Nori <nsekhar@ti.com>

1 files changed, 27 insertions, 12 deletions

diff --git a/arch/arm/mach-davinci/serial.c b/arch/arm/mach-davinci/serial.c
index 24ddb0d32a0f..f2625814c3c9 100644
--- a/arch/arm/mach-davinci/serial.c
+++ b/arch/arm/mach-davinci/serial.c
@@ -70,11 +70,33 @@ static void __init davinci_serial_reset(struct plat_serial8250_port *p)
                                  UART_DM646X_SCR_TX_WATERMARK);
 }
 
-int __init davinci_serial_init(struct davinci_uart_config *info)
+/* Enable UART clock and obtain its rate */
+int __init davinci_serial_setup_clk(unsigned instance, unsigned int *rate)
 {
-        int i;
         char name[16];
-        struct clk *uart_clk;
+        struct clk *clk;
+        struct davinci_soc_info *soc_info = &davinci_soc_info;
+        struct device *dev = &soc_info->serial_dev->dev;
+
+        sprintf(name, "uart%d", instance);
+        clk = clk_get(dev, name);
+        if (IS_ERR(clk)) {
+                pr_err("%s:%d: failed to get UART%d clock\n",
+                                        __func__, __LINE__, instance);
+                return PTR_ERR(clk);
+        }
+
+        clk_prepare_enable(clk);
+
+        if (rate)
+                *rate = clk_get_rate(clk);
+
+        return 0;
+}
+
+int __init davinci_serial_init(struct davinci_uart_config *info)
+{
+        int i, ret;
         struct davinci_soc_info *soc_info = &davinci_soc_info;
         struct device *dev = &soc_info->serial_dev->dev;
         struct plat_serial8250_port *p = dev->platform_data;
@@ -87,16 +109,9 @@ int __init davinci_serial_init(struct davinci_uart_config *info)
                 if (!(info->enabled_uarts & (1 << i)))
                         continue;
 
-                sprintf(name, "uart%d", i);
-                uart_clk = clk_get(dev, name);
-                if (IS_ERR(uart_clk)) {
-                        printk(KERN_ERR "%s:%d: failed to get UART%d clock\n",
-                                        __func__, __LINE__, i);
+                ret = davinci_serial_setup_clk(i, &p->uartclk);
+                if (ret)
                         continue;
-                }
-
-                clk_prepare_enable(uart_clk);
-                p->uartclk = clk_get_rate(uart_clk);
 
                 if (!p->membase && p->mapbase) {
                         p->membase = ioremap(p->mapbase, SZ_4K);