Re: [PATCH 0/4] MIPS: ath79: Add USB support on the TL-WR1043ND

From: Arnd Bergmann
Date: Wed Sep 09 2015 - 10:22:08 EST


On Wednesday 09 September 2015 16:14:59 Alban wrote:
> On Mon, 07 Sep 2015 15:20:42 +0200
> Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> > On Tuesday 01 September 2015 17:23:10 Alban Bedel wrote:
> > >
> > > this serie add a driver for the USB phy on the ATH79 SoCs and enable the
> > > USB port on the TL-WR1043ND. The phy controller is really trivial as it
> > > only use reset lines.
> > >
> >
> > Is this a common thing to have? If other PHY devices are like this, we
> > could instead add a simple generic PHY driver that just asserts all
> > its reset lines in the order as provided, rather than making this a
> > hardware specific driver that ends up getting copied several times.
>
> I don't know how common it is. However I agree that a simple driver that
> can start a clock and toggle a few GPIO and/or reset would make sense.
>
> However in the case of the ATH79 SoC some models have a reset line that
> is misused to force the PHY in sleep mode. Sadly this extra reset must
> be asserted for the PHY to work, so it wouldn't fit in such a generic
> design.
>
> Still we could have such a generic driver and let the ATH79 driver
> build on top of it. Honestly that's what I wanted to do, but getting
> generic drivers with DT support accepted is not easy. That's why I went
> with this driver, it is technically inferior but much easier to get
> considered for merging.

Ok, fair enough. If we end up doing a more generic driver for this,
we can still consider adding the compatible string there, potentially
with some workaround for the sleep mode.

Arnd
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