Re: [PATCH v2] pinctrl: core: print gpio in pins debugfs file

[Drew Fustini <drew@beagleboard.org>]

On Sun, Jul 19, 2020 at 03:22:01PM +0200, Drew Fustini wrote:
> If there is a gpio range mapping for the pin, then print out the gpio
> number for the pin in the debugfs 'pins' file.
> 
> Here is an example output on the BeagleBone Black from:
> /sys/kernel/debug/pinctrl/44e10800.pinmux-pinctrl-single/pins
> 
> pin 103 (PIN103) GPIO-113 44e1099c 00000027 pinctrl-single
> pin 104 (PIN104) GPIO-114 44e109a0 0000002c pinctrl-single
> pin 105 (PIN105) GPIO-115 44e109a4 00000027 pinctrl-single
> pin 106 (PIN106) GPIO-116 44e109a8 00000027 pinctrl-single
> pin 107 (PIN107) GPIO-117 44e109ac 00000027 pinctrl-single
> pin 108 (PIN108) GPIO-19 44e109b0 00000027 pinctrl-single
> pin 109 (PIN109) GPIO-20 44e109b4 00000027 pinctrl-single
> pin 110 (PIN110) NA 44e109b8 00000030 pinctrl-single
> pin 111 (PIN111) NA 44e109bc 00000028 pinctrl-single
> pin 112 (PIN112) NA 44e109c0 00000030 pinctrl-single
> pin 113 (PIN113) NA 44e109c4 00000028 pinctrl-single
> pin 114 (PIN114) NA 44e109c8 00000028 pinctrl-single
> 
> Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Suggested-by: Tony Lindgren <tony@atomide.com>
> Signed-off-by: Drew Fustini <drew@beagleboard.org>
> ---
>  drivers/pinctrl/core.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> v2 changes:
> - print 'NA' if pin does not have a GPIO number
> - change gpio_num from unsigned to unsigned int per checkpatch
> 
> diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
> index 821242bb4b16..8478025926a2 100644
> --- a/drivers/pinctrl/core.c
> +++ b/drivers/pinctrl/core.c
> @@ -1601,6 +1601,8 @@ static int pinctrl_pins_show(struct seq_file *s, void *what)
>  	struct pinctrl_dev *pctldev = s->private;
>  	const struct pinctrl_ops *ops = pctldev->desc->pctlops;
>  	unsigned i, pin;
> +	struct pinctrl_gpio_range *range;
> +	unsigned int gpio_num;
>  
>  	seq_printf(s, "registered pins: %d\n", pctldev->desc->npins);
>  
> @@ -1618,6 +1620,18 @@ static int pinctrl_pins_show(struct seq_file *s, void *what)
>  
>  		seq_printf(s, "pin %d (%s) ", pin, desc->name);
>  
> +		gpio_num = 0;
> +		list_for_each_entry(range, &pctldev->gpio_ranges, node) {
> +			if ((pin >= range->pin_base) &&
> +			    (pin < (range->pin_base + range->npins)))
> +				gpio_num = range->base + (pin - range->pin_base);
> +		}
> +
> +		if (gpio_num > 0)
> +			seq_printf(s, "GPIO-%u ", gpio_num);
> +		else
> +			seq_puts(s, "NA ");
> +
>  		/* Driver-specific info per pin */
>  		if (ops->pin_dbg_show)
>  			ops->pin_dbg_show(pctldev, s, pin);
> -- 
> 2.25.1
> 

Linus - would it better if I printed the gpio chip and line number
instead of the GPIO number?

If so, any advice on how to best convert the gpio number to the gpio
descriptor inside pinctrl_pins_show()?

Thanks,
Drew