OMAP3: PM: Ensure MUSB block can idle when driver not loaded

Otherwise, bootloaders may leave MUSB in a state which prevents
retention.

Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

2 files changed, 20 insertions, 2 deletions

diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile
index 6fd1c1f77398..3935a359e7e9 100644
--- a/arch/arm/mach-omap2/Makefile
+++ b/arch/arm/mach-omap2/Makefile
@@ -57,6 +57,4 @@ obj-$(CONFIG_MACH_NOKIA_RX51)		+= board-rx51.o \
                                            mmc-twl4030.o
 
 # Platform specific device init code
-ifeq ($(CONFIG_USB_MUSB_SOC),y)
 obj-y                                   += usb-musb.o
-endif
diff --git a/arch/arm/mach-omap2/usb-musb.c b/arch/arm/mach-omap2/usb-musb.c
index 215d463b70e3..d85296dc896c 100644
--- a/arch/arm/mach-omap2/usb-musb.c
+++ b/arch/arm/mach-omap2/usb-musb.c
@@ -31,6 +31,17 @@
 #include <mach/mux.h>
 #include <mach/usb.h>
 
+#define OTG_SYSCONFIG   (OMAP34XX_HSUSB_OTG_BASE + 0x404)
+
+static void __init usb_musb_pm_init(void)
+{
+        /* Ensure force-idle mode for OTG controller */
+        if (cpu_is_omap34xx())
+                omap_writel(0, OTG_SYSCONFIG);
+}
+
+#ifdef CONFIG_USB_MUSB_SOC
+
 static struct resource musb_resources[] = {
         [0] = { /* start and end set dynamically */
                 .flags  = IORESOURCE_MEM,
@@ -183,4 +194,13 @@ void __init usb_musb_init(void)
                 printk(KERN_ERR "Unable to register HS-USB (MUSB) device\n");
                 return;
         }
+
+        usb_musb_pm_init();
+}
+
+#else
+void __init usb_musb_init(void)
+{
+        usb_musb_pm_init();
 }
+#endif /* CONFIG_USB_MUSB_SOC */