Re: [PATCH v4 12/15] pinctrl: Add AXP192 pin control driver

From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>,
	Bartosz Golaszewski <brgl@bgdev.pl>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Chen-Yu Tsai <wens@csie.org>, Jonathan Cameron <jic23@kernel.org>,
	Sebastian Reichel <sre@kernel.org>,
	Lee Jones <lee.jones@linaro.org>,
	Liam Girdwood <lgirdwood@gmail.com>,
	Mark Brown <broonie@kernel.org>,
	Lars-Peter Clausen <lars@metafoo.de>,
	quic_gurus@quicinc.com,
	Sebastian Reichel <sebastian.reichel@collabora.com>,
	Michael Walle <michael@walle.cc>,
	Randy Dunlap <rdunlap@infradead.org>,
	"open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
	devicetree <devicetree@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-iio <linux-iio@vger.kernel.org>,
	Linux PM <linux-pm@vger.kernel.org>
Subject: Re: [PATCH v4 12/15] pinctrl: Add AXP192 pin control driver
Date: Wed, 29 Jun 2022 23:13:55 +0200	[thread overview]
Message-ID: <CAHp75Vduv_fN=2DKbOwReRoPeAYjGqSANT7UhDaRifUJ4zf5XQ@mail.gmail.com> (raw)
In-Reply-To: <20220629143046.213584-13-aidanmacdonald.0x0@gmail.com>

On Wed, Jun 29, 2022 at 4:30 PM Aidan MacDonald
<aidanmacdonald.0x0@gmail.com> wrote:
>
> The AXP192 PMIC's GPIO registers are much different from the GPIO
> registers of the AXP20x and AXP813 PMICs supported by the existing
> pinctrl-axp209 driver. It makes more sense to add a new driver for
> the AXP192, rather than add support in the existing axp20x driver.
>
> The pinctrl-axp192 driver is considerably more flexible in terms of
> register layout and should be able to support other X-Powers PMICs.
> Interrupts and pull down resistor configuration are supported too.

...

> +config PINCTRL_AXP192
> +       tristate "X-Powers AXP192 PMIC pinctrl and GPIO Support"
> +       depends on MFD_AXP20X
> +       select PINMUX
> +       select GENERIC_PINCONF
> +       select GPIOLIB
> +       help
> +         AXP PMICs provide multiple GPIOs that can be muxed for different
> +         functions. This driver bundles a pinctrl driver to select the function
> +         muxing and a GPIO driver to handle the GPIO when the GPIO function is
> +         selected.
> +         Say Y to enable pinctrl and GPIO support for the AXP192 PMIC.

What will be the module name if compiled as a module?

...

> +/**
> + * struct axp192_pctl_function - describes a function that GPIOs may have
> + *
> + * @name: Function name
> + * @muxvals: Mux values used for selecting this function, one per GPIO.
> + *           The i'th element corresponds to the i'th GPIO and is written
> + *           to the GPIO's control register field to select this function.
> + *           U8_MAX indicates that the pin does not support this function.
> + * @groups: Array of @ngroups groups listing pins supporting this function.
> + * @ngroups: Number of pin groups.
> + */
> +struct axp192_pctl_function {
> +       const char              *name;
> +       /* Mux value written to the control register to select the function (-1 if unsupported) */
> +       const u8                *muxvals;
> +       const char * const      *groups;
> +       unsigned int            ngroups;
> +};

Can it be replaced by struct function_desc?
https://elixir.bootlin.com/linux/latest/source/drivers/pinctrl/pinmux.h#L130

...

> +       ret = devm_gpiochip_add_data(dev, &pctl->chip, pctl);
> +       if (ret)
> +               dev_err_probe(dev, ret, "Failed to register GPIO chip\n");

Missed return.

-- 
With Best Regards,
Andy Shevchenko