[PATCH] lib: utils/reset: Add voltage level for gpio_reset

[Jessica Clarke]

On 24 Oct 2021, at 17:46, Xiang W <wxjstz at 126.com> wrote:
> 
> The reset voltage may be different under different platforms, so fdt
> should describe the reset level.
> 
> Signed-off-by: Xiang W <wxjstz at 126.com>
> ---
> lib/utils/reset/fdt_reset_gpio.c | 13 ++++++++++---
> 1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/utils/reset/fdt_reset_gpio.c b/lib/utils/reset/fdt_reset_gpio.c
> index 4da1450..b834522 100644
> --- a/lib/utils/reset/fdt_reset_gpio.c
> +++ b/lib/utils/reset/fdt_reset_gpio.c
> @@ -21,16 +21,19 @@
> 
> struct gpio_reset {
> 	struct gpio_pin pin;
> +	u32 active_level;
> 	u32 active_delay;
> 	u32 inactive_delay;
> };
> 
> static struct gpio_reset poweroff = {
> +	.active_level = 1,
> 	.active_delay = 100,
> 	.inactive_delay = 100
> };
> 
> static struct gpio_reset restart = {
> +	.active_level = 1,
> 	.active_delay = 100,
> 	.inactive_delay = 100
> };
> @@ -68,15 +71,15 @@ static void gpio_system_reset(u32 type, u32 reason)
> 
> 	if (reset) {
> 		/* drive it active, also inactive->active edge */
> -		gpio_direction_output(&reset->pin, 1);
> +		gpio_direction_output(&reset->pin, reset->active_level);
> 		sbi_timer_mdelay(reset->active_delay);
> 
> 		/* drive inactive, also active->inactive edge */
> -		gpio_set(&reset->pin, 0);
> +		gpio_set(&reset->pin, !reset->active_level);
> 		sbi_timer_mdelay(reset->inactive_delay);
> 
> 		/* drive it active, also inactive->active edge */
> -		gpio_set(&reset->pin, 1);
> +		gpio_set(&reset->pin, reset->active_level);
> 	}
> 	/* hang !!! */
> 	sbi_hart_hang();
> @@ -107,6 +110,10 @@ static int gpio_reset_init(void *fdt, int nodeoff,
> 			return rc;
> 	}
> 
> +	val = fdt_getprop(fdt, nodeoff, "active-level", &len);

This property is neither documented in the binding specification for
gpio-restart nor is it checked by Linux.

> +	if (len > 0)
> +		reset->active_level = !!fdt32_to_cpu(*val);
> +
> 	val = fdt_getprop(fdt, nodeoff, "active-delay-ms", &len);

In fact these are also wrong. The binding does not have a -ms suffix on
the (in)active-delay property names.

Jess