Re: [PATCH] pinctrl: ocelot: Fix alt mode for ocelot

From: Andy Shevchenko
Date: Mon Feb 06 2023 - 16:00:41 EST


On Mon, Feb 6, 2023 at 10:37 PM Horatiu Vultur
<horatiu.vultur@xxxxxxxxxxxxx> wrote:
>
> In case the driver was trying to set an alternate mode for gpio
> 0 or 32 then the mode was not set correctly. The reason is that
> there is computation error inside the function ocelot_pinmux_set_mux
> because in this case it was trying to shift to left by -1.
> Fix this by actually shifting the function bits and not the position.
>
> Fixes: 4b36082e2e09 ("pinctrl: ocelot: fix pinmuxing for pins after 31")
> Signed-off-by: Horatiu Vultur <horatiu.vultur@xxxxxxxxxxxxx>

...

> regmap_update_bits(info->map, REG_ALT(0, info, pin->pin),
> BIT(p), f << p);
> regmap_update_bits(info->map, REG_ALT(1, info, pin->pin),
> - BIT(p), f << (p - 1));
> + BIT(p), (f >> 1) << p);

I'm not sure I understand how this doesn't break anything that has a
bit 0 set in f. Is it not a problem?

--
With Best Regards,
Andy Shevchenko