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.
In addition, ensure that the iclk is enabled before attempting a write to the module SYSCONFIG register. Problem reported by Mike Chan <[email protected]> Tested-by: Mike Chan <[email protected]> Signed-off-by: Kevin Hilman <[email protected]> --- arch/arm/mach-omap2/usb-musb.c | 38 ++++++++++++++++++++++++++++++++++---- 1 files changed, 34 insertions(+), 4 deletions(-) diff --git a/arch/arm/mach-omap2/usb-musb.c b/arch/arm/mach-omap2/usb-musb.c index d85296d..3abbe5a 100644 --- a/arch/arm/mach-omap2/usb-musb.c +++ b/arch/arm/mach-omap2/usb-musb.c @@ -26,18 +26,48 @@ #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); + struct clk *iclk; + u32 phys_base; + void __iomem *otg_base; + + if (cpu_is_omap243x()) + phys_base = OMAP2_OTG_BASE; + else if (cpu_is_omap34xx()) + phys_base = OMAP34XX_HSUSB_OTG_BASE; + else + /* FIXME: add OMAP4 support */ + return; + + otg_base = ioremap(phys_base, SZ_4K); + if (WARN_ON(!otg_base)) + return; + + iclk = clk_get(NULL, "hsotgusb_ick"); + if (WARN_ON(!iclk)) + goto out; + + clk_enable(iclk); + + /* Reset OTG controller. After reset, it will be in + * force-idle, force-standby mode. */ + __raw_writel(OTG_SYSC_SOFTRESET, otg_base + OTG_SYSCONFIG); + + clk_disable(iclk); + clk_put(iclk); +out: + iounmap(otg_base); } #ifdef CONFIG_USB_MUSB_SOC -- 1.6.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
