[U-Boot] [PATCH] arm: mvebu: switch clearfog to use device-tree i2c and gpio

[Chris Packham]

On Tue, May 29, 2018 at 4:58 PM Baruch Siach <baruch at tkos.co.il> wrote:

> Hi Chris,

> On Tue, May 29, 2018 at 10:53:38AM +1200, Chris Packham wrote:
> > On Tue, May 29, 2018 at 4:11 AM Baruch Siach <baruch at tkos.co.il> wrote:
> >
> > > From: Jon Nettleton <jon at solid-run.com>
> >
> > > This switches the clearfog boards to use DM based gpio and i2c
> > > drivers.  The io expanders are configured via their device-tree
> > > entries.
> >
> > > Signed-off-by: Jon Nettleton <jon at solid-run.com>
> > > [baruch: add DT i2c aliases]
> > > Signed-off-by: Baruch Siach <baruch at tkos.co.il>
> > > ---

> [snip]

> > > -static struct marvell_io_exp io_exp[] = {
> > > -       { 0x20, 2, 0x40 },      /* Deassert both mini pcie reset
signals
> > */
> > > -       { 0x20, 6, 0xf9 },
> > > -       { 0x20, 2, 0x46 },      /* rst signals and ena USB3 current
> > limiter */
> > > -       { 0x20, 6, 0xb9 },
> > > -       { 0x20, 3, 0x00 },      /* Set SFP_TX_DIS to zero */
> > > -       { 0x20, 7, 0xbf },      /* Drive SFP_TX_DIS to zero */
> > > -};
> > > -
> >
> > Will this actually work? As far as I can see u-boot lacks a gpio-hog
> > implementation so despite the fact that these are all enumerated in the
dts
> > they won't have the same effect.
> >
> > I'd be glad to be proven wrong because I'd like to use a gpio-hog for
some
> > other boards.

> I asked Jon (back on Cc) exactly that before submitting this patch. His
> response:

>    I think that is fine. They can still be toggled and controlled via the
gpio
>    interface within u-boot. I assume once a proper patch is mainline this
will
>    just start to work.

> My testing showed now regression because of this patch.

OK. Did you test with a power cycle? I know some of the pca gpio chips
don't have a reset line so the state may be different depending on if you
power cycled or just used the reset/reboot command. It could also be that
u-boot doesn't access these devices so there's no problem.

I kinda was hoping for "here's a gpio-hog implementation @ patchwork/1234"
:) but I guess I'll have to look into making one myself.


> Thanks for reviewing,

Assuming there's no problem with power-on behaviour

Reviewed-by: Chris Packham <judge.packham at gmail.com>

> baruch

> --
>       http://baruch.siach.name/blog/                  ~. .~   Tk Open
Systems

=}------------------------------------------------ooO--U--Ooo------------{=
>     - baruch at tkos.co.il - tel: +972.52.368.4656, http://www.tkos.co.il -