Re: [PATCH] pinctrl: rockchip: fix pull setting error for rk3399

[Caesar Wang]

Doug,

ä 2016å05æ11æ 05:07, Doug Anderson åé:
> Caesar / David,
>
> On Tue, May 10, 2016 at 4:14 AM, Caesar Wang <wxt@xxxxxxxxxxxxxx> wrote:
> > From: David Wu <david.wu@xxxxxxxxxxxxxx>
> >
> > This patch fixes the pinctrl pull bias setting, since the pull up/down
> > setting is the contrary for gpio0.
> Commit message only mentions gpio0, but gpio2 is also fixed in the
> commit.  Please mention gpio2 in the commit message.

Fix it in next version.

> >  From the TRM said, the gpio0 pull polarity setting:
> > gpio0a_p (gpio0 )
> > GPIO0A PE/PS programmation section, every
> > GPIO bit corresponding to 2bits[PS:PE]
> > 2'b00: Z(Noraml operaton);
> > 2'b11: weak 1(pull-up);
> > 2'b01: weak 0(pull-down);
> > 2'b10: Z(Noraml operaton);
> Despite the fact that the typo (Noralm vs. Normal) is present in the
> TRM, maybe we should fix it here?

Yep, ditto.

> <cut>
>
> +
> +               if (ret < 0) {
> +                       dev_err(info->dev, "unknown pull setting %d\n", pull);
> nit: why change the error message?  Old message was "unsupported"
> instead of your new "unknown".  "unsupported" was better IMHO.

Okay, sound resonable.

> > -       PIN_BANK_DRV_FLAGS(2, 32, "gpio2", DRV_TYPE_IO_1V8_OR_3V0,
> > -                          DRV_TYPE_IO_1V8_OR_3V0,
> > -                          DRV_TYPE_IO_1V8_ONLY,
> > -                          DRV_TYPE_IO_1V8_ONLY
> > -                          ),
> > +       PIN_BANK_DRV_FLAGS_PULL_FLAGS(2, 32, "gpio2", DRV_TYPE_IO_1V8_OR_3V0,
> > +                                     DRV_TYPE_IO_1V8_OR_3V0,
> > +                                     DRV_TYPE_IO_1V8_ONLY,
> > +                                     DRV_TYPE_IO_1V8_ONLY,
> > +                                     PULL_TYPE_IO_DEFAULT,
> > +                                     PULL_TYPE_IO_DEFAULT,
> Are you certain that gpio2 behaves the same way?  The TRM I have says
> this for GPIO2C and GPIO2D:

+                                     PULL_TYPE_IO_1V8_ONLY,
+                                     PULL_TYPE_IO_1V8_ONLY

Yep, so this just set the gpio2c&gpio2d in this function.

> 2'b00: pervious-state
> 2'b01: weak 0(pull-down);
> 2'b10: pervious-state
> 2'b11: weak 1(pull-up);
>
> Assuming that "pervious-state" is a simple typo for "previous state"
> that would imply that it was behaving as "bus hold" and _not_ "bias
> disable".

I will say that TRM made the mistake since this is *not* exist.
Okay, fixes by the newer TRM.

> Note: if it actually is a "bus hold" state then we'll have to figure
> out how this would work with existing device trees.  I'd imagine that
> they are currently specifying "bias disable" and technically that
> might not be possible?
>
>
>
> -Doug
>
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