Re: [PATCH v2] drm/i915: Parse panel backlight controller from VBT

Jani Nikula
2016-12-12T15:27:06Z

On Thu, 08 Dec 2016, Jani Nikula <jani.nikula@intel.com> wrote:
> From: Vidya Srinivas <vidya.srinivas@intel.com>
>
> Currently the backlight controller is taken as 0. It needs to derive
> value from the VBT. Adding the necessary changes.
>
> v2 by Jani:
> - drop obsolete comments, drop redundant initialization (Bob)
> - merge debug logging into one
>
> Signed-off-by: Uma Shankar <uma.shankar@intel.com>
> Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
> Reviewed-by: Bob Paauwe <bob.j.paauwe@intel.com>
> Tested-by: Bob Paauwe <bob.j.paauwe@intel.com>
> Tested-by: Mika Kahola <mika.kahola@intel.com>
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Pushed to dinq, thanks for the patch.

BR,
Jani.

> ---
> drivers/gpu/drm/i915/i915_drv.h | 1 +
> drivers/gpu/drm/i915/intel_bios.c | 6 ++++--
> drivers/gpu/drm/i915/intel_panel.c | 17 +++--------------
> 3 files changed, 8 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 1480e733312a..786e3bb8eecf 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1716,6 +1716,7 @@ struct intel_vbt_data {
> bool present;
> bool active_low_pwm;
> u8 min_brightness; /* min_brightness/255 of max */
> + u8 controller; /* brightness controller number */
> enum intel_backlight_type type;
> } backlight;
>
> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
> index eaade27af386..1cf2fa6ec28f 100644
> --- a/drivers/gpu/drm/i915/intel_bios.c
> +++ b/drivers/gpu/drm/i915/intel_bios.c
> @@ -330,17 +330,19 @@ parse_lfp_backlight(struct drm_i915_private *dev_priv,
>
> method = &backlight_data->backlight_control[panel_type];
> dev_priv->vbt.backlight.type = method->type;
> + dev_priv->vbt.backlight.controller = method->controller;
> }
>
> 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;
> DRM_DEBUG_KMS("VBT backlight PWM modulation frequency %u Hz, "
> - "active %s, min brightness %u, level %u\n",
> + "active %s, min brightness %u, level %u, controller %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]);
> + backlight_data->level[panel_type],
> + dev_priv->vbt.backlight.controller);
> }
>
> /* Try to find sdvo panel data */
> diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
> index 3578b402d412..b01edceac650 100644
> --- a/drivers/gpu/drm/i915/intel_panel.c
> +++ b/drivers/gpu/drm/i915/intel_panel.c
> @@ -1039,10 +1039,7 @@ static void bxt_enable_backlight(struct intel_connector *connector)
> enum pipe pipe = intel_get_pipe_from_connector(connector);
> u32 pwm_ctl, val;
>
> - /* To use 2nd set of backlight registers, utility pin has to be
> - * enabled with PWM mode.
> - * The field should only be changed when the utility pin is disabled
> - */
> + /* Controller 1 uses the utility pin. */
> if (panel->backlight.controller == 1) {
> val = I915_READ(UTIL_PIN_CTL);
> if (val & UTIL_PIN_ENABLE) {
> @@ -1608,19 +1605,11 @@ bxt_setup_backlight(struct intel_connector *connector, enum pipe unused)
> struct intel_panel *panel = &connector->panel;
> u32 pwm_ctl, val;
>
> - /*
> - * For BXT hard coding the Backlight controller to 0.
> - * TODO : Read the controller value from VBT and generalize
> - */
> - panel->backlight.controller = 0;
> + panel->backlight.controller = dev_priv->vbt.backlight.controller;
>
> pwm_ctl = I915_READ(BXT_BLC_PWM_CTL(panel->backlight.controller));
>
> - /* Keeping the check if controller 1 is to be programmed.
> - * This will come into affect once the VBT parsing
> - * is fixed for controller selection, and controller 1 is used
> - * for a prticular display configuration.
> - */
> + /* Controller 1 uses the utility pin. */
> if (panel->backlight.controller == 1) {
> val = I915_READ(UTIL_PIN_CTL);
> panel->backlight.util_pin_active_low =

--
Jani Nikula, Intel Open Source Technology Center