Re: [PATCH v5 06/11] gpio: regmap: Allow to allocate regmap-irq device

Michael Walle
2025-03-19T07:16:01Z

Hi,

> GPIO controller often have support for IRQ: allow to easily allocate
> both gpio-regmap and regmap-irq in one operation.
>
> Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
> ---
> drivers/gpio/gpio-regmap.c | 23 +++++++++++++++++++++--
> include/linux/gpio/regmap.h | 15 +++++++++++++++
> 2 files changed, 36 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpio/gpio-regmap.c b/drivers/gpio/gpio-regmap.c
> index 05f8781b5204..61d5f48b445d 100644
> --- a/drivers/gpio/gpio-regmap.c
> +++ b/drivers/gpio/gpio-regmap.c
> @@ -203,6 +203,7 @@ EXPORT_SYMBOL_GPL(gpio_regmap_get_drvdata);
> */
> struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config)
> {
> + struct irq_domain *irq_domain;
> struct gpio_regmap *gpio;
> struct gpio_chip *chip;
> int ret;
> @@ -280,8 +281,26 @@ struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config
> if (ret < 0)
> goto err_free_gpio;
>
> - if (config->irq_domain) {
> - ret = gpiochip_irqchip_add_domain(chip, config->irq_domain);
> + irq_domain = config->irq_domain;
> +#ifdef CONFIG_GPIOLIB_IRQCHIP

Why do we need this ifdef?

> + if (config->regmap_irq_chip) {
> + struct regmap_irq_chip_data *irq_chip_data;
> +
> + ret = devm_regmap_add_irq_chip_fwnode(config->parent, dev_fwnode(config->parent),
> + config->regmap, config->regmap_irq_irqno,
> + config->regmap_irq_flags, 0,
> + config->regmap_irq_chip, &irq_chip_data);
> + if (ret)
> + goto err_free_gpio;
> +
> + irq_domain = regmap_irq_get_domain(irq_chip_data);
> + if (config->regmap_irq_chip_data)
> + *config->regmap_irq_chip_data = irq_chip_data;

I'm not a fan of misusing the config to return any data. Can we have
a normal gpio_regmap_get_...()? Usually, the config is on the stack
of the caller, what if you need to get irq_chip_data afterwards?
Then your caller has to save it somewhere.

Also, what is the advantage of this? Your caller doesn't have to
call devm_regmap_add_irq_chip_fwnode(), but on the flip side you
have to cram all its parameters in the gpio_regmap config. I'd like
to keep that small and simple (but still extensible!). IMHO just
setting the irq_domain is enough to achieve that.

-michael

> + }
> +#endif
> +
> + if (irq_domain) {
> + ret = gpiochip_irqchip_add_domain(chip, irq_domain);
> if (ret)
> goto err_remove_gpiochip;
> }
> diff --git a/include/linux/gpio/regmap.h b/include/linux/gpio/regmap.h
> index a9f7b7faf57b..55df2527b982 100644
> --- a/include/linux/gpio/regmap.h
> +++ b/include/linux/gpio/regmap.h
> @@ -40,6 +40,14 @@ struct regmap;
> * @drvdata: (Optional) Pointer to driver specific data which is
> * not used by gpio-remap but is provided "as is" to the
> * driver callback(s).
> + * @regmap_irq_chip: (Optional) Pointer on an regmap_irq_chip structure. If
> + * set, a regmap-irq device will be created and the IRQ
> + * domain will be set accordingly.
> + * @regmap_irq_chip_data: (Optional) Pointer on an regmap_irq_chip_data
> + * structure pointer. If set, it will be populated with a
> + * pointer on allocated regmap_irq data.
> + * @regmap_irq_irqno (Optional) The IRQ the device uses to signal interrupts.
> + * @regmap_irq_flags (Optional) The IRQF_ flags to use for the interrupt.
> *
> * The ->reg_mask_xlate translates a given base address and GPIO offset to
> * register and mask pair. The base address is one of the given register
> @@ -78,6 +86,13 @@ struct gpio_regmap_config {
> int ngpio_per_reg;
> struct irq_domain *irq_domain;
>
> +#ifdef CONFIG_GPIOLIB_IRQCHIP
> + struct regmap_irq_chip *regmap_irq_chip;
> + struct regmap_irq_chip_data **regmap_irq_chip_data;
> + int regmap_irq_irqno;
> + unsigned long regmap_irq_flags;
> +#endif
> +
> int (*reg_mask_xlate)(struct gpio_regmap *gpio, unsigned int base,
> unsigned int offset, unsigned int *reg,
> unsigned int *mask);