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From: me@felipebalbi.com (Felipe Balbi)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/2] USB: musb: omap2430: add mode change from A to B
Date: Tue, 16 Mar 2010 16:46:45 +0200	[thread overview]
Message-ID: <20100316144644.GA3870@gandalf> (raw)
In-Reply-To: <4B9F59DE.4070807@windriver.com>

Hi,

On Tue, Mar 16, 2010 at 06:13:50PM +0800, wanghui wrote:
> Thank you for your comments.
> It is right that in this function, we should only change id pin rules 
> according to user's choice, and
> leave mode transition to the ISR.
> But things are different on omap platforms, because the id pin change 
> can't trigger ISR.
> For example, when we configure the kernel, we choose musb working as OTG 
> mode. Then we plug a mini-A or a mini-B cable in the socket, after
> that we execute insmod g_ether.ko, at this time, the musb will 
> initialize to A or B working mode. how to change
> its working mode from A to B or B to A at this time? I think if the 
> platform can support id detection ISR, your method
> is workable. But on omap platforms, we must change cable(id pin state) 
> manually first, then let the controller to re-initiate a session forcibly.
> This action (clear/set session bit) don't 100% equal to send a SRP, and 
> i don't really want to send a SRP too.
> 
> If without this function for omap platforms, we can change musb working 
> mode only through rebooting kernel or rmmod/insmod gadget driver module.

it should be doable with the transceiver ISR. When you get id pin irq,
you should put the transceiver into A_IDLE state and power up vbus. MUSB
changes to host mode automatically.

-- 
balbi

  reply	other threads:[~2010-03-16 14:46 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
2010-03-15 16:10     ` Felipe Balbi
2010-03-16 10:13       ` wanghui
2010-03-16 14:46         ` Felipe Balbi [this message]
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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