Re: [PATCH 10/33] pcmcia: soc_common: switch to using gpio_descs

[Russell King - ARM Linux <linux@armlinux.org.uk>]

On Wed, Sep 14, 2016 at 01:29:04PM +0200, Linus Walleij wrote:
> On Mon, Aug 29, 2016 at 12:24 PM, Russell King
> <rmk+kernel@armlinux.org.uk> wrote:
> 
> > Switch to using the gpiod_* consumer API rather than the legacy API.
> >
> > Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
> (...)
> 
> > +int soc_pcmcia_request_gpiods(struct soc_pcmcia_socket *skt)
> > +{
> > +       int i;
> > +
> > +       for (i = 0; i < ARRAY_SIZE(skt->stat); i++) {
> > +               struct gpio_desc *desc;
> > +
> 
> Here I inserted:
> 
>         /* Skip over unnamed GPIOs, assume unused */
>         if (!skt->stat[i].name)
>             continue;
> 
> to get it working again on h3600.

Thanks, I'll add that.

> > +               desc = gpiod_get(skt->socket.dev.parent,
> > +                                skt->stat[i].name, GPIOD_IN);
> > +               if (IS_ERR(desc)) {
> > +                       dev_err(skt->socket.dev.parent,
> > +                               "Failed to get GPIO for %s: %ld\n",
> > +                               skt->stat[i].name, PTR_ERR(desc));
> > +                       __soc_pcmcia_hw_shutdown(skt, i);
> > +                       return PTR_ERR(desc);
> > +               }
> 
> 
> It bugs out for me on the legacy h3600, since it only defines
> two of these pins not all of the ARRAY_SIZE(skt->stat) pins
> will succeed and we get an error message like this:
> 
> sa11x0-pcmcia sa11x0-pcmcia: Failed to get GPIO for (null): -2
> sa11x0-pcmcia: probe of sa11x0-pcmcia failed with error -2
> 
> With the patch above it goes away and the log is silent.
> The debugfs gpio file looks like this:
> 
> cat gpio
> gpiochip0: GPIOs 0-27, gpio:
>  gpio-0   (                    |Power Button        ) in  hi
>  gpio-10  (                    |pcmcia1-detect      ) in  hi
>  gpio-11  (                    |pcmcia1-ready       ) in  hi
>  gpio-17  (                    |pcmcia0-detect      ) in  hi
>  gpio-18  (                    |Action button       ) in  hi
>  gpio-21  (                    |pcmcia0-ready       ) in  hi
>  gpio-23  (                    |dcd                 ) in  hi
>  gpio-25  (                    |cts                 ) in  lo
>  gpio-26  (                    |rts                 ) out lo
> 
> gpiochip1: GPIOs 28-43, parent: platform/htc-egpio, htc-egpio:
>  gpio-28  (                    |Flash Vpp           ) out lo
>  gpio-29  (                    |PCMCIA CARD RESET   ) out lo
>  gpio-30  (                    |OPT RESET           ) out lo
>  gpio-32  (                    |OPT NVRAM ON        ) out lo
>  gpio-33  (                    |OPT ON              ) out lo
>  gpio-34  (                    |LCD power           ) out lo
>  gpio-36  (                    |LCD control         ) out lo
>  gpio-42  (                    |LCD 5v              ) out lo
>  gpio-43  (                    |LCD 9v/-6.5v        ) out lo
> 
> Which seems like before the patch series.

Yay.

> I still suspect the PCMCIA is not really working but I have
> limited experience of the bus so I don't really know how
> to test it deeply or have my PCMCIA ethernet or harddrive
> probe properly.

Yes, to me the H3600 code looks really really really weird - the way
H3XXX_EGPIO_CARD_RESET is "shared" (badly) between both sockets is
certainly racy.  I've no idea what the semantics there are supposed
to be - I suspect that H3600 PCMCIA hasn't worked for a very long
time, or if it has, it's probably not been reliable.

> There are no regressions however, so with something like
> the above patch applied:
> Tested-by: Linus Walleij <linus.walleij@linaro.org>
> 
> For the whole patch series on H3600.

Thanks!

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