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

Jani Nikula
2016-12-08T09:26:24Z

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>
---
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 =
--
2.1.4