From: sshtylyov@mvista.com (Sergei Shtylyov)
To: linux-arm-kernel@lists.infradead.org
Subject: PXA: Handling of UDC with no VBUS pins
Date: Sun, 22 May 2011 16:32:06 +0400 [thread overview]
Message-ID: <4DD90246.9070803@ru.mvista.com> (raw)
In-Reply-To: <4DD6AF07.9060306@free.fr>
Hello.
On 20-05-2011 22:12, Robert Jarzmik wrote:
>> There are several PXA platforms which on the UDC tranceiver part have
>> a pullup pin to support connect/disconnect but no VBUS pin to detect
>> host presense. Currently such platforms are supported through udc driver
>> itself. I'd like to clean that part of pxa25x_udc/pxa27x_udc drivers and
>> to move gpio pullup handling to tranceiver.
> So, you want to concentrate USB pullup handling, right ?
>> My question is what would be better: to extend gpio-vbus to work w/o
>> VBUS pin or to write new transceiver driver only handling gpio-pullup?
> My personnal feeling is neither, let them be. The generic pullup would have to
> ask itself :
> - should the pullup be applied on D+ (on USB 2.0 and 3.0 devices) ?
> - should the pullup be applied on D- (on USB 1.1 devices) ?
Pullup on D- is only used on low speed devices, not all USB 1.1 devices.
That's how they get detected.
WBR, Sergei
prev parent reply other threads:[~2011-05-22 12:32 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-18 12:06 PXA: Handling of UDC with no VBUS pins Dmitry Eremin-Solenikov
2011-05-20 18:12 ` Robert Jarzmik
2011-05-21 18:35 ` Dmitry Eremin-Solenikov
2011-05-22 8:51 ` Robert Jarzmik
2011-05-22 9:20 ` Dmitry Eremin-Solenikov
2011-05-22 12:32 ` Sergei Shtylyov [this message]
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