From: peter.griffin@linaro.org (Peter Griffin)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 1/3] usb: host: st-hcd: Add USB HCD support for STi SoCs
Date: Thu, 24 Jul 2014 15:14:12 +0100 [thread overview]
Message-ID: <20140724141412.GA21823@griffinp-ThinkPad-X1-Carbon-2nd> (raw)
In-Reply-To: <5967609.vndF2bDyS1@wuerfel>
Hi Arnd,
<snip>
> >
> > I'm of course happy to change it if required. I see looking through that a lot
> > of other platforms do it the way you describe with a
> >
> > ehci-<platname>.c and ohci-<platname>.c
>
> Right. We are trying to gradually move some of them over to use the
> generic *hci-platform.c drivers though.
Right, ok I understand.
> > > Depending on what kind of special requirements the ST version has,
> > > this can be done either by using the generic ohci/ehci bindings
> > > with extensions where necessary, or by creating a new binding and
> > > new driver files that use 'ohci_init_driver'/'ehci_init_driver'
> > > to inherit from the common code.
> > >
> > > The first of the two approaches is preferred.
> >
> > We don't have anything particularly special, just a couple of reset lines,
> > clock, phy, etc.
>
> Ok, good. Please see Documentation/devicetree/bindings/usb/usb-?hci.txt
> then. You might actually be able to just use the existing drivers
> without new code by just adding the proper DT nodes that follow these
> bindings.
The only issues I can see with the generic versions are: -
1) We also have a powerdown line in addition to the reset line both of which are
exposed via reset controller API, so I would need to add that into ehci-platform
and ohci-platform.
2) We have a magic poke in st_ehci_configure_bus of the current driver to configure
the AHB to ST bus protocol convertor IP. I'm not quite sure where I could hook that
in (sorry... slightly pulling back on my "nothing special comment" a bit ;-).
3) We also set the rate of the ohci clock, which the generic driver doesn't do.
regards,
Peter.
next prev parent reply other threads:[~2014-07-24 14:14 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-24 11:00 [PATCH v2 0/3] Add USB HCD support for STi SoCs Peter Griffin
2014-07-24 11:00 ` [PATCH v2 1/3] usb: host: st-hcd: " Peter Griffin
2014-07-24 11:14 ` Arnd Bergmann
2014-07-24 12:22 ` Peter Griffin
2014-07-24 13:01 ` Arnd Bergmann
2014-07-24 14:14 ` Peter Griffin [this message]
2014-07-24 16:26 ` Arnd Bergmann
2014-07-24 14:26 ` Alan Stern
2014-07-24 11:20 ` Lee Jones
2014-07-24 11:00 ` [PATCH v2 2/3] usb: host: st-hcd: Add st-hcd devicetree bindings documentation Peter Griffin
2014-07-24 11:16 ` Lee Jones
2014-07-24 11:00 ` [PATCH v2 3/3] MAINTAINERS: Add st-hcd to ARCH/STI architecture Peter Griffin
2014-07-24 11:14 ` Lee Jones
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