[Intel-gfx] [PATCH] drm/i915: Parsing LFP brightness control from VBT

[Daniel Vetter]

On Mon, Dec 15, 2014 at 03:58:21PM +0530, Vandana Kannan wrote:
> From: Deepak M <m.deepak at intel.com>
> 
> LFP brighness control from the VBT block 43 indicates which
> controller is used for brightness.
> LFP1 brightness control method:
> Bit 7-4 = This field controller number of the brightnes controller.
> 0 = Controller 0
> 1 = Controller 1
> 2 = Controller 2
> 3 = Controller 3
> Others = Reserved
> Bits 3-0 = This field specifies the brightness control pin to be used on the
> platform.
> 0 = PMIC pin is used for brightness control
> 1 = LPSS PWM is used for brightness control
> 2 = Display DDI is used for brightness control
> 3 = CABC method to control brightness
> Others = Reserved
> 
> Adding the above fields in dev_priv->vbt and corresponding changes in
> parse_backlight()
> 
> v2: Jani's review comments addressed
> 	- Move PWM definitions to intel_bios.h
> 	- Moving vbt_version to intel_vbt_data
> 	- Rename brightness to bl_ctrl_data
> 	- Logging just control_pin instead of string
> 	- Avoid adding vbt_version in dev_priv
> 	- Since only DDI option is available as of now, let control pin DDI
> 	affect dev_priv->vbt.backlight.present
> 
> v3: Jani's review comments addressed
> 	- Drop control_pin
> 	- Use bdb->version
> 	- set controller to 0 instead of using control pin define
> 	- check controller bounds
> 	- remove superfluous changes in intel_parse_bios
> 
> Signed-off-by: Deepak M <m.deepak at intel.com>
> Signed-off-by: Vandana Kannan <vandana.kannan at intel.com>
> Reviewed-by: Jani Nikula <jani.nikula at intel.com>

Queued for -next, thanks for the patch.
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_drv.h   |  1 +
>  drivers/gpu/drm/i915/intel_bios.c | 20 ++++++++++++++++++++
>  drivers/gpu/drm/i915/intel_bios.h | 11 +++++++++++
>  3 files changed, 32 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 11e85cb..f4fef28 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1355,6 +1355,7 @@ struct intel_vbt_data {
>  		bool present;
>  		bool active_low_pwm;
>  		u8 min_brightness;	/* min_brightness/255 of max */
> +		u8 controller;		/* brightness controller number */
>  	} backlight;
>  
>  	/* MIPI DSI */
> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
> index 3f17825..65b1fbc 100644
> --- a/drivers/gpu/drm/i915/intel_bios.c
> +++ b/drivers/gpu/drm/i915/intel_bios.c
> @@ -314,6 +314,7 @@ parse_lfp_backlight(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
>  {
>  	const struct bdb_lfp_backlight_data *backlight_data;
>  	const struct bdb_lfp_backlight_data_entry *entry;
> +	const struct bdb_lfp_backlight_control_data *bl_ctrl_data;
>  
>  	backlight_data = find_section(bdb, BDB_LVDS_BACKLIGHT);
>  	if (!backlight_data)
> @@ -326,6 +327,7 @@ parse_lfp_backlight(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
>  	}
>  
>  	entry = &backlight_data->data[panel_type];
> +	bl_ctrl_data = &backlight_data->blc_ctl[panel_type];
>  
>  	dev_priv->vbt.backlight.present = entry->type == BDB_BACKLIGHT_TYPE_PWM;
>  	if (!dev_priv->vbt.backlight.present) {
> @@ -337,12 +339,30 @@ parse_lfp_backlight(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
>  	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;
> +
> +	dev_priv->vbt.backlight.controller = 0;
> +	if (bdb->version >= 191) {
> +		dev_priv->vbt.backlight.present =
> +				bl_ctrl_data->pin == BLC_CONTROL_PIN_DDI;
> +		if (!dev_priv->vbt.backlight.present) {
> +			DRM_DEBUG_KMS("BL control pin is not DDI (pin %u)\n",
> +					bl_ctrl_data->pin);
> +			return;
> +		}
> +		if (bl_ctrl_data->controller == 1)
> +			dev_priv->vbt.backlight.controller =
> +				bl_ctrl_data->controller;
> +	}
> +
>  	DRM_DEBUG_KMS("VBT backlight PWM modulation frequency %u Hz, "
>  		      "active %s, min brightness %u, level %u\n",
>  		      dev_priv->vbt.backlight.pwm_freq_hz,
>  		      dev_priv->vbt.backlight.active_low_pwm ? "low" : "high",
>  		      dev_priv->vbt.backlight.min_brightness,
>  		      backlight_data->level[panel_type]);
> +
> +	DRM_DEBUG_KMS("VBT BL controller %u\n",
> +		dev_priv->vbt.backlight.controller);
>  }
>  
>  /* Try to find sdvo panel data */
> diff --git a/drivers/gpu/drm/i915/intel_bios.h b/drivers/gpu/drm/i915/intel_bios.h
> index a6a8710..9a7202e 100644
> --- a/drivers/gpu/drm/i915/intel_bios.h
> +++ b/drivers/gpu/drm/i915/intel_bios.h
> @@ -402,10 +402,21 @@ struct bdb_lfp_backlight_data_entry {
>  	u8 obsolete3;
>  } __packed;
>  
> +#define BLC_CONTROL_PIN_PMIC		0
> +#define BLC_CONTROL_PIN_LPSS_PWM	1
> +#define BLC_CONTROL_PIN_DDI		2
> +#define BLC_CONTROL_PIN_CABC		3
> +
> +struct bdb_lfp_backlight_control_data {
> +	u8 controller:4;
> +	u8 pin: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_data blc_ctl[16];
>  } __packed;
>  
>  struct aimdb_header {
> -- 
> 2.0.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch