From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH 2/2] USB: musb: omap2430: add mode change from A to B Date: Mon, 15 Mar 2010 14:22:38 +0300 Message-ID: <4B9E187E.6090802@ru.mvista.com> References: <1268648622-28529-1-git-send-email-Hui.Wang@windriver.com> <1268648622-28529-2-git-send-email-Hui.Wang@windriver.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1268648622-28529-2-git-send-email-Hui.Wang-CWA4WttNNZF54TAoqtyWWQ@public.gmane.org> Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Wang Hui Cc: tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org, felipe.balbi-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-omap@vger.kernel.org Hello. Wang Hui wrote: > On omap2/3 series platforms, the musb can't raise id pin change > detection interrupt, so we must change otg mode through sysfs > interface manually. Currently when the musb is in B mode, if we > want musb to be changed to A mode, we should plug a mini-A cable > and then execute echo host > /sys/devices/platform/musb_hdrc/mode. > But if the musb is in A mode, we can't change it to B mode through > this method. > To solve this problem, add a process for sending end session request. > This process works like this, if the musb is in A mode, it will send > an end session request first, then it will follow original routine: > start a new session, during this session, it will identify whether > A or B is plugging in the socket, then it will init controller to A > or B mode according to its identification. > > Usage: change cable as you desired, > change musb mode by #>echo host[peripheral] > /sys/devices/\ > platform/musb_hdrc/mode, > then you will get required musb mode. > > Signed-off-by: Wang Hui > --- > drivers/usb/musb/omap2430.c | 5 +++++ > 1 files changed, 5 insertions(+), 0 deletions(-) > > diff --git a/drivers/usb/musb/omap2430.c b/drivers/usb/musb/omap2430.c > index 3fe1686..b02897e 100644 > --- a/drivers/usb/musb/omap2430.c > +++ b/drivers/usb/musb/omap2430.c > @@ -194,6 +194,11 @@ int musb_platform_set_mode(struct musb *musb, u8 musb_mode) > { > u8 devctl = musb_readb(musb->mregs, MUSB_DEVCTL); > > + if ((devctl & MUSB_DEVCTL_BDEVICE) == 0x0) { > + devctl &= ~MUSB_DEVCTL_SESSION; > + musb_writeb(musb->mregs, MUSB_DEVCTL, devctl); > + } > + > devctl |= MUSB_DEVCTL_SESSION; > musb_writeb(musb->mregs, MUSB_DEVCTL, devctl); > The whole musb_platform_set_mode() seems to be implemented incorrectly on OMAPs -- it shouldn't touch the DevCtl.Session bit. This function should control the ID pin override instead -- if the controller supports it. SRP must be initiated thru other means, i.e. 'srp' file in sysfs. WBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html