linux-kernel - Re: [PATCH v1 2/2] gpio: dwapb: Switch to use fwnode_irq

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Date:   Wed, 2 Jun 2021 17:05:46 +0300
From:   Serge Semin <fancer.lancer@...il.com>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc:     Serge Semin <Sergey.Semin@...kalelectronics.ru>,
        linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
        Hoan Tran <hoan@...amperecomputing.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <bgolaszewski@...libre.com>
Subject: Re: [PATCH v1 2/2] gpio: dwapb: Switch to use fwnode_irq_get()

Hello Andy

On Tue, Jun 01, 2021 at 07:21:28PM +0300, Andy Shevchenko wrote:
> We have open coded variant of fwnode_irq_get() in dwapb_get_irq().
> Replace it with a simple call.

Sometime ago I was trying to figure out a way to simplify this part of
the driver by using the platform_get_irq_optional() method for both
ACPI and OF cases. As you must have already found out by yourself it
didn't work out because of DW APB GPIO DT-nodes are supposed to have
sub-nodes with ports description. The OF-descriptors of these
sub-nodes aren't touched by the platform_get_irq_optional() method, it
just fails to detect IRQ-controller because it only works with the
device OF-node. So I gave up and decided to leave the code as is. I
can't remember now why I haven't used fwnode_irq_get() here. Most
likely I just preferred a direct of_irq_get() invocation here just for
clarity, since the only way we'd be calling fwnode_irq_get() here is
to actually get IRQ number from the OF-node anyway, while the
acpi_irq_get() method call made from the method fwnode_irq_get() will
hardly ever be required here. If you think otherwise or I missing
something please tell me.

Anyway by applying your patch at least we'll save a few lines of the
code and may in future have swnode-base IRQs support in the
fwnode_irq_get() method. So it still worths merging in. Thanks for
suggesting this change.

Acked-by: Serge Semin <fancer.lancer@...il.com>
Tested-by: Serge Semin <fancer.lancer@...il.com>

-Sergey

> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
> ---
>  drivers/gpio/gpio-dwapb.c | 12 ++++--------
>  1 file changed, 4 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
> index 939701c1465e..7d61f5821e32 100644
> --- a/drivers/gpio/gpio-dwapb.c
> +++ b/drivers/gpio/gpio-dwapb.c
> @@ -528,17 +528,13 @@ static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
>  static void dwapb_get_irq(struct device *dev, struct fwnode_handle *fwnode,
>  			  struct dwapb_port_property *pp)
>  {
> -	struct device_node *np = NULL;
> -	int irq = -ENXIO, j;
> -
> -	if (fwnode_property_read_bool(fwnode, "interrupt-controller"))
> -		np = to_of_node(fwnode);
> +	int irq, j;
>  
>  	for (j = 0; j < pp->ngpio; j++) {
> -		if (np)
> -			irq = of_irq_get(np, j);
> -		else if (has_acpi_companion(dev))
> +		if (has_acpi_companion(dev))
>  			irq = platform_get_irq_optional(to_platform_device(dev), j);
> +		else
> +			irq = fwnode_irq_get(fwnode, j);
>  		if (irq > 0)
>  			pp->irq[j] = irq;
>  	}
> -- 
> 2.30.2
>