From mboxrd@z Thu Jan 1 00:00:00 1970 From: Niilo Minkkinen Subject: Re: [PATCH] OMAP3: PM: reset USB OTG module on boot Date: Wed, 24 Jun 2009 09:53:43 +0300 Message-ID: <1245826423.6022.5.camel@niilo-u810> References: <1245803237-30891-1-git-send-email-khilman@deeprootsystems.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from smtp.nokia.com ([192.100.122.233]:44445 "EHLO mgw-mx06.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751897AbZFXG5K (ORCPT ); Wed, 24 Jun 2009 02:57:10 -0400 In-Reply-To: <1245803237-30891-1-git-send-email-khilman@deeprootsystems.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: ext Kevin Hilman Cc: "linux-omap@vger.kernel.org" On Wed, 2009-06-24 at 02:27 +0200, ext Kevin Hilman wrote: > 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 > > Tested-by: Mike Chan > Signed-off-by: Kevin Hilman > --- > If no comments/issues, this will be applied to PM branch and > backported to pm-2.6.29. > > arch/arm/mach-omap2/usb-musb.c | 21 ++++++++++++++++++--- > 1 files changed, 18 insertions(+), 3 deletions(-) > > diff --git a/arch/arm/mach-omap2/usb-musb.c b/arch/arm/mach-omap2/usb-musb.c > index d85296d..85731b8 100644 > --- a/arch/arm/mach-omap2/usb-musb.c > +++ b/arch/arm/mach-omap2/usb-musb.c > @@ -32,12 +32,27 @@ > #include > > #define OTG_SYSCONFIG (OMAP34XX_HSUSB_OTG_BASE + 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; > + > + if (!cpu_is_omap34xx()) > + return; > + > + iclk = clk_get(NULL, "hsotgusb_ick"); > + if (WARN_ON(!iclk)) > + return; > + > + clk_enable(iclk); > + > + /* Reset OTG controller. After reset, it will be in > + * force-idle, force-standby mode. */ > + omap_writel(OTG_SYSC_SOFTRESET, OTG_SYSCONFIG); Do you think, this is safe to do w/o waiting reset to be finished like : ? + omap_writel( SOFTRST, OTG_SYSCONFIG ); /* acquire RESET */ + start = jiffies; + timeout = start + msecs_to_jiffies(10); /* max 10 ms */ + while (!time_after(jiffies, timeout)) /* wait until RESET OK */ + if ( omap_readl(OTG_SYSSTATUS) & RESETDONE ) + break; SOFTRST & RESETDONE already defined in omap2430.h > + > + clk_disable(iclk); > + clk_put(iclk); > } > > #ifdef CONFIG_USB_MUSB_SOC