ARM: SAMSUNG: fix watchdog reset issue with clk_get()

clkdev framework uses global mutex to protect clock tree, so it is not
possible to call clk_get() in interrupt context. This patch fixes this
issue and makes system reset by watchdog call working again.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

3 files changed, 17 insertions, 7 deletions

diff --git a/arch/arm/plat-samsung/clock.c b/arch/arm/plat-samsung/clock.c
index 302c42670bd1..3b4451979d1b 100644
--- a/arch/arm/plat-samsung/clock.c
+++ b/arch/arm/plat-samsung/clock.c
@@ -64,6 +64,17 @@ static LIST_HEAD(clocks);
  */
 DEFINE_SPINLOCK(clocks_lock);
 
+/* Global watchdog clock used by arch_wtd_reset() callback */
+struct clk *s3c2410_wdtclk;
+static int __init s3c_wdt_reset_init(void)
+{
+        s3c2410_wdtclk = clk_get(NULL, "watchdog");
+        if (IS_ERR(s3c2410_wdtclk))
+                printk(KERN_WARNING "%s: warning: cannot get watchdog clock\n", __func__);
+        return 0;
+}
+arch_initcall(s3c_wdt_reset_init);
+
 /* enable and disable calls for use with the clk struct */
 
 static int clk_null_enable(struct clk *clk, int enable)
diff --git a/arch/arm/plat-samsung/include/plat/clock.h b/arch/arm/plat-samsung/include/plat/clock.h
index 87d5b38a86fb..8f95700d296e 100644
--- a/arch/arm/plat-samsung/include/plat/clock.h
+++ b/arch/arm/plat-samsung/include/plat/clock.h
@@ -121,3 +121,6 @@ extern int s3c64xx_sclk_ctrl(struct clk *clk, int enable);
 
 extern void s3c_pwmclk_init(void);
 
+/* Global watchdog clock used by arch_wtd_reset() callback */
+
+extern struct clk *s3c2410_wdtclk;
diff --git a/arch/arm/plat-samsung/include/plat/watchdog-reset.h b/arch/arm/plat-samsung/include/plat/watchdog-reset.h
index 54b762acb5a0..40dbb2b0ae22 100644
--- a/arch/arm/plat-samsung/include/plat/watchdog-reset.h
+++ b/arch/arm/plat-samsung/include/plat/watchdog-reset.h
@@ -10,6 +10,7 @@
  * published by the Free Software Foundation.
 */
 
+#include <plat/clock.h>
 #include <plat/regs-watchdog.h>
 #include <mach/map.h>
 
@@ -19,17 +20,12 @@
 
 static inline void arch_wdt_reset(void)
 {
-        struct clk *wdtclk;
-
         printk("arch_reset: attempting watchdog reset\n");
 
         __raw_writel(0, S3C2410_WTCON);   /* disable watchdog, to be safe  */
 
-        wdtclk = clk_get(NULL, "watchdog");
-        if (!IS_ERR(wdtclk)) {
-                clk_enable(wdtclk);
-        } else
-                printk(KERN_WARNING "%s: warning: cannot get watchdog clock\n", __func__);
+        if (s3c2410_wdtclk)
+                clk_enable(s3c2410_wdtclk);
 
         /* put initial values into count and data */
         __raw_writel(0x80, S3C2410_WTCNT);