[ARM] 3361/1: S3C24XX - add USB bus clock source
Patch from Ben Dooks
Add USB bus clock definition for 48MHz fed to OHCI and gadget cores
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mach-s3c2410/s3c2440-clock.c b/arch/arm/mach-s3c2410/s3c2440-clock.c
index 7bca0be..57a1597 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 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;