Re: [PATCH] drivers: iio: dac: ad5592r: add gpio_chip names

[Jonathan Cameron <jic23@kernel.org>]

On Wed, 1 Feb 2023 13:11:30 +0000
"Miclaus, Antoniu" <Antoniu.Miclaus@analog.com> wrote:

> --
> Antoniu Miclăuş
> 
> > -----Original Message-----
> > From: Jonathan Cameron <jic23@kernel.org>
> > Sent: Wednesday, November 23, 2022 10:49 PM
> > To: Miclaus, Antoniu <Antoniu.Miclaus@analog.com>
> > Cc: linux-iio@vger.kernel.org; linux-kernel@vger.kernel.org
> > Subject: Re: [PATCH] drivers: iio: dac: ad5592r: add gpio_chip names
> > 
> > [External]
> > 
> > On Thu, 17 Nov 2022 11:01:30 +0200
> > Antoniu Miclaus <antoniu.miclaus@analog.com> wrote:
> >   
> > > Add array of explicit gpio names for the `gpiochip` structure of
> > > ad5592r, mainly for debug purposes.  
> > Can you give an example of when this is more useful than the offset?
> > (which I'm assuming is also available when debugging?)
> > 
> > Jonathan
> >   
> Hello Jonathan,
> 
> I guess this patch is not mandatory. It is a gpio_chip structure member that was left unpopulated.
> Also, I think it is nice to see explicitly the gpios under cat /sys/kernel/debug/gpio alongside the others.
> This is the current output when trying to debug on a rpi (without the patch applied):
> 
> analog@analog:~ $ sudo cat /sys/kernel/debug/gpio
> gpiochip0: GPIOs 0-57, parent: platform/fe200000.gpio, pinctrl-bcm2711:
>  gpio-0   (ID_SDA              )
>  gpio-1   (ID_SCL              )
>  gpio-2   (SDA1                )
>  gpio-3   (SCL1                )
>  gpio-4   (GPIO_GCLK           )
>  gpio-5   (GPIO5               )
>  gpio-6   (GPIO6               )
> ....
> gpiochip2: GPIOs 496-503, parent: spi/spi0.0, spi0.0, can sleep:
> 
> gpiochip1: GPIOs 504-511, parent: platform/soc:firmware:gpio, raspberrypi-exp-gpio, can sleep:
>  gpio-504 (BT_ON               )
>  gpio-505 (WL_ON               )
>  gpio-506 (PWR_LED_OFF         |led1                ) out lo ACTIVE LOW
>  gpio-507 (GLOBAL_RESET        )
>  gpio-508 (VDD_SD_IO_SEL       |vdd-sd-io           ) out hi
>  gpio-509 (CAM_GPIO            |power_ctrl          ) out lo
>  gpio-510 (SD_PWR_ON           |sd_vcc_reg          ) out hi
>  gpio-511 (SD_OC_N             )
> 
> The gpiochip2, corresponding to ad5592r has no explicit gpios, due to the fact that the
> gpio names were assigned.

Thanks for the info.

Applied to the togreg branch of iio.git and pushed out as testing for 0-day
to poke at it an see if we missed anything.

We are a bit tight timing wise, so this might end up in next cycle.

Jonathan

> 
> Regards,
> > >
> > > Since the gpios are configurable via the dts, generic names are
> > > used.
> > >
> > > Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
> > > ---
> > >  drivers/iio/dac/ad5592r-base.c | 5 +++++
> > >  1 file changed, 5 insertions(+)
> > >
> > > diff --git a/drivers/iio/dac/ad5592r-base.c b/drivers/iio/dac/ad5592r-base.c
> > > index 7a9b5fc1e579..076bc9ecfb49 100644
> > > --- a/drivers/iio/dac/ad5592r-base.c
> > > +++ b/drivers/iio/dac/ad5592r-base.c
> > > @@ -124,6 +124,10 @@ static int ad5592r_gpio_request(struct gpio_chip  
> > *chip, unsigned offset)  
> > >  	return 0;
> > >  }
> > >
> > > +static const char * const ad5592r_gpio_names[] = {
> > > +	"GPIO0", "GPIO1", "GPIO2", "GPIO3", "GPIO4", "GPIO5", "GPIO6",  
> > "GPIO7",  
> > > +};
> > > +
> > >  static int ad5592r_gpio_init(struct ad5592r_state *st)
> > >  {
> > >  	if (!st->gpio_map)
> > > @@ -140,6 +144,7 @@ static int ad5592r_gpio_init(struct ad5592r_state  
> > *st)  
> > >  	st->gpiochip.set = ad5592r_gpio_set;
> > >  	st->gpiochip.request = ad5592r_gpio_request;
> > >  	st->gpiochip.owner = THIS_MODULE;
> > > +	st->gpiochip.names = ad5592r_gpio_names;
> > >
> > >  	mutex_init(&st->gpio_lock);
> > >  
>