[PATCH] gpio: Get rid of gpio_hog_probe_all()

[Quentin Schulz]

Hi Marek,

On 9/19/22 21:45, Marek Vasut wrote:
> The gpio_hog_probe_all() functionality can be perfectly well replaced by
> DM_FLAG_PROBE_AFTER_BIND DM flag, which would trigger .probe() callback
> of each GPIO hog driver instance after .bind() and thus configure the
> hogged GPIO accordingly.
> 
> Signed-off-by: Marek Vasut <marex at denx.de>
> ---
> Cc: Heinrich Schuchardt <xypron.glpk at gmx.de>
> Cc: Samuel Holland <samuel at sholland.org>
> Cc: Simon Glass <sjg at chromium.org>
> ---
>   common/board_r.c           |  3 ---
>   common/spl/spl.c           |  3 ---
>   doc/README.gpio            |  6 ++----
>   drivers/gpio/gpio-uclass.c | 25 ++-----------------------
>   include/asm-generic/gpio.h |  8 --------
>   5 files changed, 4 insertions(+), 41 deletions(-)
> 
> diff --git a/common/board_r.c b/common/board_r.c
> index 56eb60fa275..c556aa5a073 100644
> --- a/common/board_r.c
> +++ b/common/board_r.c
> @@ -750,9 +750,6 @@ static init_fnc_t init_sequence_r[] = {
>   	initr_status_led,
>   #endif
>   	/* PPC has a udelay(20) here dating from 2002. Why? */
> -#if defined(CONFIG_GPIO_HOG)
> -	gpio_hog_probe_all,
> -#endif
>   #ifdef CONFIG_BOARD_LATE_INIT
>   	board_late_init,
>   #endif
> diff --git a/common/spl/spl.c b/common/spl/spl.c
> index 29e0898f03d..683e0dfc526 100644
> --- a/common/spl/spl.c
> +++ b/common/spl/spl.c
> @@ -770,9 +770,6 @@ void board_init_r(gd_t *dummy1, ulong dummy2)
>   		}
>   	}
>   
> -	if (CONFIG_IS_ENABLED(GPIO_HOG))
> -		gpio_hog_probe_all();
> -
>   #if CONFIG_IS_ENABLED(BOARD_INIT)
>   	spl_board_init();
>   #endif
> diff --git a/doc/README.gpio b/doc/README.gpio
> index 548ff37b8cc..d253f654fad 100644
> --- a/doc/README.gpio
> +++ b/doc/README.gpio
> @@ -2,10 +2,8 @@
>   GPIO hog (CONFIG_GPIO_HOG)
>   --------
>   
> -All the GPIO hog are initialized in gpio_hog_probe_all() function called in
> -board_r.c just before board_late_init() but you can also acces directly to
> -the gpio with gpio_hog_lookup_name().
> -
> +All the GPIO hog are initialized using DM_FLAG_PROBE_AFTER_BIND DM flag
> +after bind().
>   
>   Example, for the device tree:
>   
> diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
> index 0ed32b72170..32df0448a7b 100644
> --- a/drivers/gpio/gpio-uclass.c
> +++ b/drivers/gpio/gpio-uclass.c
> @@ -315,34 +315,11 @@ static int gpio_hog_probe(struct udevice *dev)
>   	return 0;
>   }
>   
> -int gpio_hog_probe_all(void)
> -{
> -	struct udevice *dev;
> -	int ret;
> -	int retval = 0;
> -
> -	for (uclass_first_device(UCLASS_NOP, &dev);
> -	     dev;
> -	     uclass_find_next_device(&dev)) {
> -		if (dev->driver == DM_DRIVER_GET(gpio_hog)) {
> -			ret = device_probe(dev);
> -			if (ret) {
> -				printf("Failed to probe device %s err: %d\n",
> -				       dev->name, ret);
> -				retval = ret;
> -			}
> -		}
> -	}
> -
> -	return retval;
> -}
> -
>   int gpio_hog_lookup_name(const char *name, struct gpio_desc **desc)
>   {
>   	struct udevice *dev;
>   
>   	*desc = NULL;
> -	gpio_hog_probe_all();
>   	if (!uclass_get_device_by_name(UCLASS_NOP, name, &dev)) {
>   		struct gpio_hog_priv *priv = dev_get_priv(dev);
>   
> @@ -1503,6 +1480,8 @@ static int gpio_post_bind(struct udevice *dev)
>   								 &child);
>   				if (ret)
>   					return ret;
> +
> +				dev_or_flags(child, DM_FLAG_PROBE_AFTER_BIND);

I replaced this line with:

+                               /*
+                                * Make sure gpio-hogs are probed after bind
+                                * since hogs can be essential to the 
hardware
+                                * system.
+                                */
+                               dev_or_flags(child, 
DM_FLAG_PROBE_AFTER_BIND);
+
+                               /*
+                                * Since gpio-hog is a U_BOOT_DRIVER and not
+                                * a U_BOOT_CLASS, the DM core does not bind
+                                * it and therefore it's up to this 
driver to
+                                * set the DM_FLAG_PRE_RELOC appropriately.
+                                */
+                               if (ofnode_pre_reloc(node))
+                                       dev_or_flags(child, 
DM_FLAG_PRE_RELOC);

and it works fine for me now (no dependency on the core DM patch I sent 
just a few minutes ago; I assume it's because we revert-recursively 
probe the parents of such devices?)

Cheers,
Quentin