Rather than simply setting force-idle mode on boot, do a reset of the
OTG module.  This really ensures that any bootloader/bootstrap code
that leaves it active will not prevent future retention.  After reset,
OTG module will be in force-idle, force-standby mode.

Problem reported by Mike Chan <[email protected]>

Tested-by: Mike Chan <[email protected]>
Signed-off-by: Kevin Hilman <[email protected]>
---
I decided to drop clock stuff from this patch as the current
code is not doing it either.  This simply replaces the 
force-idle with a soft reset, and uses ioremap instead of
omap_write().  

This will only be a temporary patch in the pm branch until
omap_hwmod is integrated and is doing the full module reset.

 arch/arm/mach-omap2/usb-musb.c |   22 ++++++++++++++++++----
 1 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/arch/arm/mach-omap2/usb-musb.c b/arch/arm/mach-omap2/usb-musb.c
index d85296d..3efa19c 100644
--- a/arch/arm/mach-omap2/usb-musb.c
+++ b/arch/arm/mach-omap2/usb-musb.c
@@ -26,18 +26,32 @@
 
 #include <linux/usb/musb.h>
 
+#include <asm/sizes.h>
+
 #include <mach/hardware.h>
 #include <mach/irqs.h>
 #include <mach/mux.h>
 #include <mach/usb.h>
 
-#define OTG_SYSCONFIG  (OMAP34XX_HSUSB_OTG_BASE + 0x404)
+#define OTG_SYSCONFIG     0x404
+#define OTG_SYSC_SOFTRESET BIT(1)
 
 static void __init usb_musb_pm_init(void)
 {
-       /* Ensure force-idle mode for OTG controller */
-       if (cpu_is_omap34xx())
-               omap_writel(0, OTG_SYSCONFIG);
+       void __iomem *otg_base;
+
+       if (!cpu_is_omap34xx())
+               return;
+
+       otg_base = ioremap(OMAP34XX_HSUSB_OTG_BASE, SZ_4K);
+       if (WARN_ON(!otg_base))
+               return;
+
+       /* Reset OTG controller.  After reset, it will be in
+        * force-idle, force-standby mode. */
+       __raw_writel(OTG_SYSC_SOFTRESET, otg_base + OTG_SYSCONFIG);
+
+       iounmap(otg_base);
 }
 
 #ifdef CONFIG_USB_MUSB_SOC
-- 
1.6.3.2

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