From: sshtylyov@mvista•com (Sergei Shtylyov)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 2/2] USB: musb: omap2430: add mode change from A to B
Date: Mon, 15 Mar 2010 14:22:38 +0300 [thread overview]
Message-ID: <4B9E187E.6090802@ru.mvista.com> (raw)
In-Reply-To: <1268648622-28529-2-git-send-email-Hui.Wang@windriver.com>
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 <Hui.Wang@windriver•com>
> ---
> 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
next prev parent reply other threads:[~2010-03-15 11:22 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-15 10:23 [PATCH 1/2] USB: musb: add two states to handle vbus error Wang Hui
2010-03-15 10:23 ` [PATCH 2/2] USB: musb: omap2430: add mode change from A to B Wang Hui
2010-03-15 11:22 ` Sergei Shtylyov [this message]
2010-03-15 16:10 ` Felipe Balbi
2010-03-16 10:13 ` wanghui
2010-03-16 14:46 ` Felipe Balbi
2010-07-22 15:16 ` Kan-Ru Chen
2010-07-22 16:40 ` Felipe Balbi
2010-07-23 4:38 ` Kan-Ru Chen
2010-03-16 10:49 ` [PATCH 1/2] USB: musb: add two states to handle vbus error wanghui
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