linux-kernel - Re: [PATCH v2 2/2] gpiolib: support parsing gpio three-cell interrupts scheme

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Message-ID: <20250301232944-GYA55471@gentoo>
Date: Sat, 1 Mar 2025 23:29:44 +0000
From: Yixun Lan <dlan@...too.org>
To: Linus Walleij <linus.walleij@...aro.org>,
	Bartosz Golaszewski <brgl@...ev.pl>,
	Thomas Gleixner <tglx@...utronix.de>
Cc: Alex Elder <elder@...cstar.com>, Inochi Amaoto <inochiama@...il.com>,
	linux-kernel@...r.kernel.org, linux-gpio@...r.kernel.org,
	linux-riscv@...ts.infradead.org, spacemit@...ts.linux.dev
Subject: Re: [PATCH v2 2/2] gpiolib: support parsing gpio three-cell
 interrupts scheme

Hi Linus, Thomas:

On 07:15 Sun 02 Mar     , Yixun Lan wrote:
> gpio irq which using three-cell scheme should always call
> instance_match() function to find the correct irqdomain.
> 
> The select() function will be called with !DOMAIN_BUS_ANY,
> so for specific gpio irq driver, it need to set bus token
> explicitly, something like:
>   irq_domain_update_bus_token(girq->domain, DOMAIN_BUS_WIRED);
> 
> Signed-off-by: Yixun Lan <dlan@...too.org>
> ---
>  drivers/gpio/gpiolib-of.c |  8 ++++++++
>  drivers/gpio/gpiolib-of.h |  6 ++++++
>  drivers/gpio/gpiolib.c    | 23 +++++++++++++++++++----
>  3 files changed, 33 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
> index 2e537ee979f3e2b6e8d5f86f3e121a66f2a8e083..e19904569fb1b71c1fff237132d17050ef02b074 100644
> --- a/drivers/gpio/gpiolib-of.c
> +++ b/drivers/gpio/gpiolib-of.c
> @@ -1187,3 +1187,11 @@ void of_gpiochip_remove(struct gpio_chip *chip)
>  {
>  	of_node_put(dev_of_node(&chip->gpiodev->dev));
>  }
> +
> +bool of_gpiochip_instance_match(struct gpio_chip *gc, unsigned int index)
> +{
> +	if (gc->of_node_instance_match)
> +		return gc->of_node_instance_match(gc, index);
> +
> +	return false;
> +}
> diff --git a/drivers/gpio/gpiolib-of.h b/drivers/gpio/gpiolib-of.h
> index 16d6ac8cb156c02232ea868b755bbdc46c78e3c7..3eebfac290c571e3b90e4437295db8eaacb021a3 100644
> --- a/drivers/gpio/gpiolib-of.h
> +++ b/drivers/gpio/gpiolib-of.h
> @@ -22,6 +22,7 @@ struct gpio_desc *of_find_gpio(struct device_node *np,
>  			       unsigned long *lookupflags);
>  int of_gpiochip_add(struct gpio_chip *gc);
>  void of_gpiochip_remove(struct gpio_chip *gc);
> +bool of_gpiochip_instance_match(struct gpio_chip *gc, unsigned int index);
>  int of_gpio_count(const struct fwnode_handle *fwnode, const char *con_id);
>  #else
>  static inline struct gpio_desc *of_find_gpio(struct device_node *np,
> @@ -33,6 +34,11 @@ static inline struct gpio_desc *of_find_gpio(struct device_node *np,
>  }
>  static inline int of_gpiochip_add(struct gpio_chip *gc) { return 0; }
>  static inline void of_gpiochip_remove(struct gpio_chip *gc) { }
> +static inline bool of_gpiochip_instance_match(struct gpio_chip *gc,
> +					      unsigned int index)
> +{
> +	return false;
> +}
>  static inline int of_gpio_count(const struct fwnode_handle *fwnode,
>  				const char *con_id)
>  {
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index 679ed764cb143c4b3357106de1570e8d38441372..266be465b9103c17861a0d76f2dfbf1f1de3a073 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -1449,10 +1449,9 @@ static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
>  						   unsigned long *hwirq,
>  						   unsigned int *type)
>  {
> -	/* We support standard DT translation */
> -	if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
> -		return irq_domain_translate_twocell(d, fwspec, hwirq, type);
> -	}
> +	/* We support standard DT translation up to three cells */
> +	if (is_of_node(fwspec->fwnode))
> +		return irq_domain_translate_cells(d, fwspec, hwirq, type);

I'm not sure if you like this way for calling generic cells parser here,
as it should work for 1, 2, 3 cells model, which save a few lines meanwhile

otherwise we end something like

	if (is_of_node(fwspec->fwnode) {
		if (fwspec->param_count == 2) {
			return irq_domain_translate_twocell(d, fwspec, hwirq, type);
		if (fwspec->param_count == 3) {
			return irq_domain_translate_threecell(d, fwspec, hwirq, type);
	}
>  
>  	/* This is for board files and others not using DT */
>  	if (is_fwnode_irqchip(fwspec->fwnode)) {
> @@ -1754,9 +1753,25 @@ static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
>  	irq_set_chip_data(irq, NULL);
>  }
>  
> +static int gpiochip_irq_select(struct irq_domain *d, struct irq_fwspec *fwspec,
> +			enum irq_domain_bus_token bus_token)
> +{
> +	struct fwnode_handle *fwnode = fwspec->fwnode;
> +	struct gpio_chip *gc = d->host_data;
> +	unsigned int index = fwspec->param[0];
> +
> +	if (fwspec->param_count == 3 && is_of_node(fwnode))
> +		return of_gpiochip_instance_match(gc, index);
> +
> +	/* Fallback for twocells */
> +	return ((fwnode != NULL) && (d->fwnode == fwnode) &&
> +		(d->bus_token == bus_token));
> +}
> +
>  static const struct irq_domain_ops gpiochip_domain_ops = {
>  	.map	= gpiochip_irq_map,
>  	.unmap	= gpiochip_irq_unmap,
> +	.select	= gpiochip_irq_select,
>  	/* Virtually all GPIO irqchips are twocell:ed */
>  	.xlate	= irq_domain_xlate_twocell,
>  };
> 
> -- 
> 2.48.1
> 

-- 
Yixun Lan (dlan)
Gentoo Linux Developer
GPG Key ID AABEFD55