[Intel-gfx] [PATCH 3/5] drm/i915: Parse LFP brightness control field in VBT

[Deepak, M]

> -----Original Message-----
> From: Nikula, Jani
> Sent: Tuesday, March 29, 2016 8:31 PM
> To: intel-gfx at lists.freedesktop.org; Deepak, M <m.deepak at intel.com>
> Cc: Nikula, Jani <jani.nikula at intel.com>
> Subject: [PATCH 3/5] drm/i915: Parse LFP brightness control field in VBT
> 
> From: Deepak M <m.deepak at intel.com>
> 
> These fields in VBT indicates the PWM source which is used and also the
> controller number.
> 
> v2 by Jani: check for out of bounds access, some renames, change default
> type, etc.
> 
> Signed-off-by: Deepak M <m.deepak at intel.com>
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.h       | 1 +
>  drivers/gpu/drm/i915/intel_bios.c     | 9 +++++++++
>  drivers/gpu/drm/i915/intel_bios.h     | 8 ++++++++
>  drivers/gpu/drm/i915/intel_vbt_defs.h | 6 ++++++
>  4 files changed, 24 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h
> b/drivers/gpu/drm/i915/i915_drv.h index 0906dfd7b1a9..4a76b7b2dbd9
> 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1472,6 +1472,7 @@ struct intel_vbt_data {
>  		bool present;
>  		bool active_low_pwm;
>  		u8 min_brightness;	/* min_brightness/255 of max */
> +		enum intel_backlight_type type;
>  	} backlight;
> 
>  	/* MIPI DSI */
> diff --git a/drivers/gpu/drm/i915/intel_bios.c
> b/drivers/gpu/drm/i915/intel_bios.c
> index 6985519921b4..2f639820aded 100644
> --- a/drivers/gpu/drm/i915/intel_bios.c
> +++ b/drivers/gpu/drm/i915/intel_bios.c
> @@ -304,6 +304,15 @@ parse_lfp_backlight(struct drm_i915_private
> *dev_priv,
>  		return;
>  	}
> 
> +	dev_priv->vbt.backlight.type = INTEL_BACKLIGHT_DISPLAY_DDI;
> +	if (bdb->version >= 191 &&
> +	    get_blocksize(backlight_data) >= sizeof(*backlight_data)) {
> +		const struct bdb_lfp_backlight_control_method *method;
> +
> +		method = &backlight_data->backlight_control[panel_type];
> +		dev_priv->vbt.backlight.type = method->type;
> +	}
> +
>  	dev_priv->vbt.backlight.pwm_freq_hz = entry->pwm_freq_hz;
>  	dev_priv->vbt.backlight.active_low_pwm = entry-
> >active_low_pwm;
>  	dev_priv->vbt.backlight.min_brightness = entry->min_brightness;
> diff --git a/drivers/gpu/drm/i915/intel_bios.h
> b/drivers/gpu/drm/i915/intel_bios.h
> index 149c3226e895..df6ce3e3d26f 100644
> --- a/drivers/gpu/drm/i915/intel_bios.h
> +++ b/drivers/gpu/drm/i915/intel_bios.h
> @@ -30,6 +30,14 @@
>  #ifndef _INTEL_BIOS_H_
>  #define _INTEL_BIOS_H_
> 
> +enum intel_backlight_type {
> +	INTEL_BACKLIGHT_PMIC,
> +	INTEL_BACKLIGHT_LPSS,
> +	INTEL_BACKLIGHT_DISPLAY_DDI,
> +	INTEL_BACKLIGHT_CABC,
[Deepak, M] Better to rename CABC to PANEL_PWM, because CABC is not the source of the PWM. There may be some panel which have the panel PWM but may not support CABC.
> +	INTEL_BACKLIGHT_PANEL_DRIVER_INTERFACE,
> +};
> +
>  struct edp_power_seq {
>  	u16 t1_t3;
>  	u16 t8;
> diff --git a/drivers/gpu/drm/i915/intel_vbt_defs.h
> b/drivers/gpu/drm/i915/intel_vbt_defs.h
> index 749dceab7c02..2191076c3ff6 100644
> --- a/drivers/gpu/drm/i915/intel_vbt_defs.h
> +++ b/drivers/gpu/drm/i915/intel_vbt_defs.h
> @@ -440,10 +440,16 @@ struct bdb_lfp_backlight_data_entry {
>  	u8 obsolete3;
>  } __packed;
> 
> +struct bdb_lfp_backlight_control_method {
> +	u8 type:4;
> +	u8 controller:4;
> +} __packed;
> +
>  struct bdb_lfp_backlight_data {
>  	u8 entry_size;
>  	struct bdb_lfp_backlight_data_entry data[16];
>  	u8 level[16];
> +	struct bdb_lfp_backlight_control_method backlight_control[16];
>  } __packed;
> 
>  struct aimdb_header {
> --
> 2.1.4