RE: [PATCH v3] OMAP2/3/4: PM: reset USB OTG module on boot

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Kevin

>-----Original Message-----
>From: linux-omap-owner@xxxxxxxxxxxxxxx [mailto:linux-omap-owner@xxxxxxxxxxxxxxx] On Behalf Of Kevin
>Hilman
>Sent: Wednesday, June 24, 2009 1:28 PM
>To: linux-omap@xxxxxxxxxxxxxxx
>Subject: [PATCH v3] OMAP2/3/4: PM: reset USB OTG module on boot
>

Have some more comments that I should have given before the re-spin v3 !!

>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 <mikechan@xxxxxxxxxx>
>
>Tested-by: Mike Chan <mikechan@xxxxxxxxxx>
>Signed-off-by: Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx>
>---
>Updates from v2
>- reset for OMAP2 as well (needs update for OMAP4, see FIXME)
>
> arch/arm/mach-omap2/usb-musb.c |   37 +++++++++++++++++++++++++++++++++----
> 1 files changed, 33 insertions(+), 4 deletions(-)
>
>diff --git a/arch/arm/mach-omap2/usb-musb.c b/arch/arm/mach-omap2/usb-musb.c
>index d85296d..1ea2ac7 100644
>--- a/arch/arm/mach-omap2/usb-musb.c
>+++ b/arch/arm/mach-omap2/usb-musb.c
>@@ -26,18 +26,47 @@
>
> #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))

Need to iounmap(otg_base); and clk_put() in case of error
Goto error;
>+		return;
>+
>+	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);

error:
>+	clk_put(iclk);
>+	iounmap(otg_base);
> }
>
> #ifdef CONFIG_USB_MUSB_SOC
>--
>1.6.3.2
>
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