[RFT,v7,2/6] ARM: pxa: Convert Spitz LEDs to GPIO descriptors

Sharp's Spitz board still uses the legacy GPIO interface for configuring
its two onboard LEDs.

Convert them to use the GPIO descriptor interface.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Duje Mihanović <duje.mihanovic@skole.hr>
---
 arch/arm/mach-pxa/spitz.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

On Tuesday, October 10, 2023 1:12:05 PM CEST Bartosz Golaszewski wrote:
> Gah! I should have noticed this earlier but this is a perfect
> candidate for using hogs. Can you use gpiod_add_hogs() from
> linux/gpio/machine.h instead? That would save you having the lookup
> and the static leds descriptor array.

On Tue, Oct 10, 2023 at 6:33 PM Duje Mihanović <duje.mihanovic@skole.hr> wrote:
>
> On Tuesday, October 10, 2023 1:12:05 PM CEST Bartosz Golaszewski wrote:
> > Gah! I should have noticed this earlier but this is a perfect
> > candidate for using hogs. Can you use gpiod_add_hogs() from
> > linux/gpio/machine.h instead? That would save you having the lookup
> > and the static leds descriptor array.
>
> From what I can tell, the hogs keep a certain pin at a certain state as long
> as the machine is powered on. Is this really what we want to do with LEDs or
> am I missing something?
>

It doesn't seem like anyone is using these GPIOs once they're
requested? Wouldn't the above definitios be analogous to:

GPIO_HOG("pxa-gpio", SPITZ_GPIO_LED_ORANGE, NULL, GPIO_ACTIVE_HIGH, GPIOD_ASIS)
GPIO_HOG("pxa-gpio", SPITZ_GPIO_LED_GREEN, NULL, GPIO_ACTIVE_HIGH, GPIOD_ASIS)

?

Bart

On Tue, Oct 10, 2023 at 7:39 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote:

> It doesn't seem like anyone is using these GPIOs once they're
> requested? Wouldn't the above definitios be analogous to:
>
> GPIO_HOG("pxa-gpio", SPITZ_GPIO_LED_ORANGE, NULL, GPIO_ACTIVE_HIGH, GPIOD_ASIS)
> GPIO_HOG("pxa-gpio", SPITZ_GPIO_LED_GREEN, NULL, GPIO_ACTIVE_HIGH, GPIOD_ASIS)

They are used:
+       spitz_gpio_leds[0].gpiod = leds->desc[0];
+       spitz_gpio_leds[1].gpiod = leds->desc[1];

The descriptors are passed to the leds-gpio driver.

But wait: no.

This whole thing:

+static struct gpio_descs *leds;
+
(...)
+       leds = gpiod_get_array_optional(&spitz_led_device.dev,
+                       NULL, GPIOD_ASIS);
+       spitz_gpio_leds[0].gpiod = leds->desc[0];
+       spitz_gpio_leds[1].gpiod = leds->desc[1];

Just delete all that.

The leds-gpio driver will request and use the lines.

It was just so unorthodox that I missed it. Adding the descriptor
table is enough.

Yours,
Linus Walleij

On Tue, Oct 10, 2023 at 10:04 PM Linus Walleij <linus.walleij@linaro.org> wrote:
>
> On Tue, Oct 10, 2023 at 7:39 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
>
> > It doesn't seem like anyone is using these GPIOs once they're
> > requested? Wouldn't the above definitios be analogous to:
> >
> > GPIO_HOG("pxa-gpio", SPITZ_GPIO_LED_ORANGE, NULL, GPIO_ACTIVE_HIGH, GPIOD_ASIS)
> > GPIO_HOG("pxa-gpio", SPITZ_GPIO_LED_GREEN, NULL, GPIO_ACTIVE_HIGH, GPIOD_ASIS)
>
> They are used:
> +       spitz_gpio_leds[0].gpiod = leds->desc[0];
> +       spitz_gpio_leds[1].gpiod = leds->desc[1];
>
> The descriptors are passed to the leds-gpio driver.
>
> But wait: no.
>
> This whole thing:
>
> +static struct gpio_descs *leds;
> +
> (...)
> +       leds = gpiod_get_array_optional(&spitz_led_device.dev,
> +                       NULL, GPIOD_ASIS);
> +       spitz_gpio_leds[0].gpiod = leds->desc[0];
> +       spitz_gpio_leds[1].gpiod = leds->desc[1];
>
> Just delete all that.
>
> The leds-gpio driver will request and use the lines.
>
> It was just so unorthodox that I missed it. Adding the descriptor
> table is enough.

Ah, good catch. Your suggestion is of course the correct one.

Bart

>
> Yours,
> Linus Walleij