Re: [PATCH] pinctrl: ingenic: Fix regmap on X series SoCs

From: Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
To: Paul Cercueil <paul@crapouillou.net>
Cc: linus.walleij@linaro.org, linux-mips@vger.kernel.org,
	linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] pinctrl: ingenic: Fix regmap on X series SoCs
Date: Thu, 10 Feb 2022 23:10:45 +0000	[thread overview]
Message-ID: <YgWbdYDiVQyHkHiJ@localhost> (raw)
In-Reply-To: <DD537R.K2D13DXGNPGH@crapouillou.net>

On Thu, Feb 10, 2022 at 11:03:13AM +0000, Paul Cercueil wrote:
> Hi Aidan,
> 
> Le mer., févr. 9 2022 at 23:04:54 +0000, Aidan MacDonald 
> <aidanmacdonald.0x0@gmail.com> a écrit :
> > The X series Ingenic SoCs have a shadow GPIO group which
> > is at a higher offset than the other groups, and is used
> > for all GPIO configuration. The regmap did not take this
> > offset into account and set max_register too low. Writes
> > to the shadow group registers were blocked, which made it
> > impossible to change any pin configuration.
> > 
> > Fix this by pretending there are at least 8 chips on any
> > 'X' SoC for the purposes of calculating max_register. This
> > ensures the shadow group is accessible.
> 
> I don't like your solution, it sounds very hacky. I think it would make 
> more sense to use a dedicated x1000_pinctrl_regmap_config that would be 
> used for the X1000 SoC. That would also allow you to express that there 
> are no registers in the 0x400-0x700 range (through 
> regmap_config.wr_table / .rd_table).
> 
> Cheers,
> -Paul
> 

That's fine, I'll put together a v2 patch using the approach you suggest.
I think all the 'X' SoCs will require a similar regmap as they're using
ingenic_gpio_shadow_* functions too, but I'll check their datasheets to
be sure.

> > Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
> > ---
> >  drivers/pinctrl/pinctrl-ingenic.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/pinctrl/pinctrl-ingenic.c 
> > b/drivers/pinctrl/pinctrl-ingenic.c
> > index 2712f51eb238..9d2bccda50f1 100644
> > --- a/drivers/pinctrl/pinctrl-ingenic.c
> > +++ b/drivers/pinctrl/pinctrl-ingenic.c
> > @@ -4168,7 +4168,10 @@ static int __init ingenic_pinctrl_probe(struct 
> > platform_device *pdev)
> >  		return PTR_ERR(base);
> > 
> >  	regmap_config = ingenic_pinctrl_regmap_config;
> > -	regmap_config.max_register = chip_info->num_chips * 
> > chip_info->reg_offset;
> > +	if (chip_info->version >= ID_X1000)
> > +		regmap_config.max_register = MIN(8, chip_info->num_chips) * 
> > chip_info->reg_offset;
> > +	else
> > +		regmap_config.max_register = chip_info->num_chips * 
> > chip_info->reg_offset;
> > 
> >  	jzpc->map = devm_regmap_init_mmio(dev, base, &regmap_config);
> >  	if (IS_ERR(jzpc->map)) {
> > --
> > 2.34.1
> > 
> 
> 