Re: [PATCH i-g-t 6/6] tools/intel_vbt_decode: Decode the backlight control method type

[Jani Nikula <jani.nikula@intel.com>]

On Mon, 29 Sep 2025, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Decode the backlight control method type to a human readable form.
>
> TODO: looks like the we might not be handling some of this
>       correctly on the kernel side...
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  tools/intel_vbt_decode.c | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/tools/intel_vbt_decode.c b/tools/intel_vbt_decode.c
> index 68d02aee9f5a..e42aed542612 100644
> --- a/tools/intel_vbt_decode.c
> +++ b/tools/intel_vbt_decode.c
> @@ -734,6 +734,17 @@ static const char * const i2c_speed_str[] = {
>  	[3] = "1 MHz",
>  };
>  
> +static const char * const control_type_str[] = {
> +	[0] = "PMIC pin",
> +	[1] = "LPSS PWM",
> +	[2] = "PWM from Display Engine/Aux Default",
> +	[3] = "CABC/PWM From LCD Panel",

The spec says, "CABC method to control brightness/PWM From LCD Panel",
but feels like it's been butchered at some point. It's DSI DCS, right?
And it might or might not have CABC.

*shrug*

> +	[4] = "Panel driver interface",
> +	[5] = "Legacy VESA eDP AUX Interface",
> +	[6] = "PWM from Display Engine/VESA eDP1.5 SCR AUX Interface",
> +	[7] = "PWM from Display Engine/Custom eDP AUX Interface",
> +};
> +
>  static void dump_backlight_info(struct context *context,
>  				const struct bdb_block *block)
>  {
> @@ -782,7 +793,8 @@ static void dump_backlight_info(struct context *context,
>  
>  		control = &backlight->backlight_control[i];
>  
> -		printf("\t\tControl type: %u\n", control->type);
> +		printf("\t\tControl type: %s (%u)\n",
> +		       to_str(control_type_str, control->type), control->type);
>  		printf("\t\tController: %u\n", control->controller);
>  
>  		if (context->bdb->version < 234)

-- 
Jani Nikula, Intel