[PATCH 1/9] ARM: boards: protonic-imx6: prtvt7 hardkey inputs are active low

[Robin van der Gracht]

Hi Ahmand,

On 2022-06-20 09:51, Ahmad Fatoum wrote:
> Hello,
> 
> On 17.06.22 10:44, Marco Felsch wrote:
>> On 22-06-17, Sascha Hauer wrote:
>>>> Or, it is active low and your patch is correct :D
>>> 
>>> If they are, can we add a comment or _N suffix to the names?
>> 
>> Does barebox not have gpiod? The board code just should check if it is
>> active or not. Whatever active means in this case.
> 
> There is gpiod_get(), but there's also gpio-keys support. See
> drivers/input/specialkeys.c for an example on how to register an input
> notifier.

I dont think I can use gpiod_get() due to the device tree format for
gpio-keys. I didn't know about the input_notifier framework. I'll check
if I can get it to work with that as-well.


> Robin, did you test this works with barebox v2022.05.0?
> I'd have assumed this to be broken by f349b662674e ("gpio: allocate dynamic
> gpio numbers top down"). Especially, with deep probe, you can't and 
> shouldn't
> depend on GPIO expanders numbering being fixed. If you use an input 
> notifier,
> you should sidestep this issue altogether.

I just notiched that as well. I was just making some changes including the
feadback from this thread:

diff --git a/arch/arm/boards/protonic-imx6/board.c 
b/arch/arm/boards/protonic-imx6/board.c
index cdbb8debe6..374ec11364 100644
--- a/arch/arm/boards/protonic-imx6/board.c
+++ b/arch/arm/boards/protonic-imx6/board.c
@@ -635,17 +635,24 @@ static int prt_imx6_init_kvg_yaco(struct prt_imx6_priv 
*priv)
         return prt_imx6_init_kvg_power(priv, PW_MODE_KVG_WITH_YACO);
  }

-#define GPIO_KEY_F6     (0xe0 + 5)
-#define GPIO_KEY_CYCLE  (0xe0 + 2)
-
  static int prt_imx6_init_prtvt7(struct prt_imx6_priv *priv)
  {
-       /* This function relies heavely on the gpio-pca9539 driver */
+       int gpio_f6, gpio_cycle;
+       struct device_d *gpio_expander;
+
+       gpio_expander = get_device_by_name("pca95390");
+       if (!gpio_expander) {
+               dev_err(priv->dev, "Can't find pca9539 gpio expander\n");
+               return -ENODEV;
+       }
+
+       gpio_cycle = gpio_get_num(gpio_expander, 2);
+       gpio_request_one(gpio_cycle, GPIOF_ACTIVE_LOW | GPIOF_DIR_IN, 
"Cycle");

-       gpio_direction_input(GPIO_KEY_F6);
-       gpio_direction_input(GPIO_KEY_CYCLE);
+       gpio_f6 = gpio_get_num(gpio_expander, 5);
+       gpio_request_one(gpio_f6, GPIOF_ACTIVE_LOW | GPIOF_DIR_IN, "F6");

-       if (gpio_get_value(GPIO_KEY_CYCLE) && gpio_get_value(GPIO_KEY_F6))
+       if (!(gpio_is_active(gpio_cycle) && gpio_is_active(gpio_f6)))
                 priv->no_usb_check = 1;

         return 0;

I'll make a proposal with the input_notifier aswell.

- Robin