3 files changed, 37 insertions, 2 deletions

diff --git a/arch/arm/mach-s3c2410/clock.c b/arch/arm/mach-s3c2410/clock.c
index 95c6d46c3dd6..fec02c92f95f 100644
--- a/arch/arm/mach-s3c2410/clock.c
+++ b/arch/arm/mach-s3c2410/clock.c
@@ -53,7 +53,8 @@
 /* clock information */
 
 static LIST_HEAD(clocks);
-static DEFINE_MUTEX(clocks_mutex);
+
+DEFINE_MUTEX(clocks_mutex);
 
 /* old functions */
 
@@ -296,6 +297,13 @@ static struct clk clk_p = {
 	.ctrlbit	= 0,
 };
 
+struct clk clk_usb_bus = {
+	.name		= "usb-bus",
+	.id		= -1,
+	.rate		= 0,
+	.parent		= &clk_upll,
+};
+
 /* clocks that could be registered by external code */
 
 static int s3c24xx_dclk_enable(struct clk *clk, int enable)
@@ -606,6 +614,10 @@ int __init s3c24xx_setup_clocks(unsigned long xtal,
 	if (s3c24xx_register_clock(&clk_p) < 0)
 		printk(KERN_ERR "failed to register cpu pclk\n");
 
+
+	if (s3c24xx_register_clock(&clk_usb_bus) < 0)
+		printk(KERN_ERR "failed to register usb bus clock\n");
+
 	/* register clocks from clock array */
 
 	for (ptr = 0; ptr < ARRAY_SIZE(init_clocks); ptr++, clkp++) {
diff --git a/arch/arm/mach-s3c2410/clock.h b/arch/arm/mach-s3c2410/clock.h
index 32864b30c1e0..01bb458bf8eb 100644
--- a/arch/arm/mach-s3c2410/clock.h
+++ b/arch/arm/mach-s3c2410/clock.h
@@ -34,11 +34,15 @@ extern struct clk s3c24xx_clkout0;
 extern struct clk s3c24xx_clkout1;
 extern struct clk s3c24xx_uclk;
 
+extern struct clk clk_usb_bus;
+
 /* exports for arch/arm/mach-s3c2410
  *
  * Please DO NOT use these outside of arch/arm/mach-s3c2410
 */
 
+extern struct mutex clocks_mutex;
+
 extern int s3c24xx_clkcon_enable(struct clk *clk, int enable);
 extern int s3c24xx_register_clock(struct clk *clk);
 
diff --git a/arch/arm/mach-s3c2410/s3c2440-clock.c b/arch/arm/mach-s3c2410/s3c2440-clock.c
index 7bca0be87384..57a15974d4b5 100644
--- a/arch/arm/mach-s3c2410/s3c2440-clock.c
+++ b/arch/arm/mach-s3c2410/s3c2440-clock.c
@@ -31,6 +31,7 @@
 #include <linux/sysdev.h>
 #include <linux/interrupt.h>
 #include <linux/ioport.h>
+#include <linux/mutex.h>
 #include <linux/clk.h>
 
 #include <asm/hardware.h>
@@ -111,20 +112,38 @@ static struct clk s3c2440_clk_ac97 = {
 static int s3c2440_clk_add(struct sys_device *sysdev)
 {
 	unsigned long camdivn = __raw_readl(S3C2440_CAMDIVN);
+	unsigned long clkdivn;
 	struct clk *clk_h;
 	struct clk *clk_p;
+	struct clk *clk_upll;
 
 	printk("S3C2440: Clock Support, DVS %s\n",
 	       (camdivn & S3C2440_CAMDIVN_DVSEN) ? "on" : "off");
 
 	clk_p = clk_get(NULL, "pclk");
 	clk_h = clk_get(NULL, "hclk");
+	clk_upll = clk_get(NULL, "upll");
 
-	if (IS_ERR(clk_p) || IS_ERR(clk_h)) {
+	if (IS_ERR(clk_p) || IS_ERR(clk_h) || IS_ERR(clk_upll)) {
 		printk(KERN_ERR "S3C2440: Failed to get parent clocks\n");
 		return -EINVAL;
 	}
 
+	/* check rate of UPLL, and if it is near 96MHz, then change
+	 * to using half the UPLL rate for the system */
+
+	if (clk_get_rate(clk_upll) > (94 * MHZ)) {
+		clk_usb_bus.rate = clk_get_rate(clk_upll) / 2;
+
+		mutex_lock(&clocks_mutex);
+
+		clkdivn = __raw_readl(S3C2410_CLKDIVN);
+		clkdivn |= S3C2440_CLKDIVN_UCLK;
+		__raw_writel(camdivn, S3C2410_CLKDIVN);
+
+		mutex_unlock(&clocks_mutex);
+	}
+
 	s3c2440_clk_cam.parent = clk_h;
 	s3c2440_clk_ac97.parent = clk_p;
 	s3c2440_clk_cam_upll.parent = clk_upll;