From: David Lechner <david@lechnology.com>
To: Bin Liu <b-liu@ti.com>,
petr@barix.com, sergei.shtylyov@cogentembedded.com,
khilman@kernel.org, nsekhar@ti.com,
Rob Herring <robh+dt@kernel.org>, Pawel Moll <pawel.moll@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Ian Campbell <ijc+devicetree@hellion.org.uk>,
Kumar Gala <galak@codeaurora.org>,
Kishon Vijay Abraham I <kishon@ti.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Alan Stern <stern@rowland.harvard.edu>,
Lee Jones <lee.jones@linaro.org>,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-usb@vger.kernel.org
Subject: Re: [PATCH v4 3/7] phy: Add set_mode callback
Date: Mon, 9 May 2016 17:47:59 -0500 [thread overview]
Message-ID: <5731139F.4020602@lechnology.com> (raw)
In-Reply-To: <20160504183903.GB27414@uda0271908>
On 05/04/2016 01:39 PM, Bin Liu wrote:
> On Wed, May 04, 2016 at 01:20:36PM -0500, David Lechner wrote:
>> This is something I actually plan on using because the device I am
>> using (LEGO MINDSTORMS EV3) is not wired for OTG, so the callback is
>> needed to override the ID and VBUS signals when switching between
>> host and peripheral mode.
>
> Have you already tested this? I never tried changing mode via sysfs, but
> by quickly reviewing the code, I am wondering how it works. the core
> only calls ops->set_mode() but nothing else. To really switch the mode,
> the driver has to talk to the root hub, and manipulate the SESSION
> bit...
>
I have tested this now and it works. It works because by setting the
mode, we are overriding the VBUS and ID signals, which in turn triggers
interrupts. I have tested switching to both peripheral mode and host
mode via sysfs. Host mode has some issues if you are using a
self-powered device, but that is a bug in the da8xx glue layer and
shouldn't hold up this patch series. Aside from that, it works exactly
as expected.
next prev parent reply other threads:[~2016-05-09 22:48 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-14 18:35 [PATCH v4 0/7] da8xx USB PHY (was da8xx USB clocks) David Lechner
2016-04-14 18:35 ` [PATCH v4 1/7] mfd: da8xx-cfgchip: New header file for CFGCHIP registers David Lechner
2016-04-25 14:08 ` Lee Jones
2016-04-14 18:35 ` [PATCH v4 2/7] dt-bindings: Add bindings for phy-da8xx-usb David Lechner
2016-04-15 10:48 ` Sergei Shtylyov
2016-04-15 16:13 ` David Lechner
2016-04-15 17:05 ` Sergei Shtylyov
2016-04-14 18:35 ` [PATCH v4 3/7] phy: Add set_mode callback David Lechner
2016-05-04 18:10 ` Bin Liu
2016-05-04 18:20 ` David Lechner
2016-05-04 18:39 ` Bin Liu
2016-05-04 19:48 ` David Lechner
2016-05-09 22:47 ` David Lechner [this message]
2016-04-14 18:35 ` [PATCH v4 4/7] phy: da8xx-usb: new driver for DA8xx SoC USB PHY David Lechner
2016-04-19 8:03 ` Kishon Vijay Abraham I
2016-04-14 18:35 ` [PATCH v4 5/7] usb: ohci-da8xx: Remove code that references mach David Lechner
2016-04-14 18:35 ` [PATCH v4 6/7] usb: musb: da8xx: Use devm in probe David Lechner
2016-04-14 18:35 ` [PATCH v4 7/7] usb: musb: da8xx: Remove mach code David Lechner
2016-05-04 16:24 ` [PATCH v4 0/7] da8xx USB PHY (was da8xx USB clocks) David Lechner
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