drm/i915: parse backlight modulation frequency from the BIOS VBT

We don't actually do anything with the information yet, but parse and
log what's in the VBT.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 67f2ca1..b0a6e76 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1184,6 +1184,11 @@ struct intel_vbt_data {
        int edp_bpp;
        struct edp_power_seq edp_pps;
 
+       struct {
+               u16 pwm_freq_hz;
+               bool active_low_pwm;
+       } backlight;
+
        /* MIPI DSI */
        struct {
                u16 panel_id;

diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index f88e507..f220419 100644 (file)
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -281,6 +281,34 @@ parse_lfp_panel_data(struct drm_i915_private *dev_priv,
        }
 }
 
+static void
+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;
+
+       backlight_data = find_section(bdb, BDB_LVDS_BACKLIGHT);
+       if (!backlight_data)
+               return;
+
+       if (backlight_data->entry_size != sizeof(backlight_data->data[0])) {
+               DRM_DEBUG_KMS("Unsupported backlight data entry size %u\n",
+                             backlight_data->entry_size);
+               return;
+       }
+
+       entry = &backlight_data->data[panel_type];
+
+       dev_priv->vbt.backlight.pwm_freq_hz = entry->pwm_freq_hz;
+       dev_priv->vbt.backlight.active_low_pwm = entry->active_low_pwm;
+       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",
+                     entry->min_brightness,
+                     backlight_data->level[panel_type]);
+}
+
 /* Try to find sdvo panel data */
 static void
 parse_sdvo_panel_data(struct drm_i915_private *dev_priv,
@@ -894,6 +922,7 @@ intel_parse_bios(struct drm_device *dev)
        parse_general_features(dev_priv, bdb);
        parse_general_definitions(dev_priv, bdb);
        parse_lfp_panel_data(dev_priv, bdb);
+       parse_lfp_backlight(dev_priv, bdb);
        parse_sdvo_panel_data(dev_priv, bdb);
        parse_sdvo_device_mapping(dev_priv, bdb);
        parse_device_mapping(dev_priv, bdb);

diff --git a/drivers/gpu/drm/i915/intel_bios.h b/drivers/gpu/drm/i915/intel_bios.h
index 81ed58c..282de5e 100644 (file)
--- a/drivers/gpu/drm/i915/intel_bios.h
+++ b/drivers/gpu/drm/i915/intel_bios.h
@@ -373,6 +373,22 @@ struct bdb_lvds_lfp_data {
        struct bdb_lvds_lfp_data_entry data[16];
 } __packed;
 
+struct bdb_lfp_backlight_data_entry {
+       u8 type:2;
+       u8 active_low_pwm:1;
+       u8 obsolete1:5;
+       u16 pwm_freq_hz;
+       u8 min_brightness;
+       u8 obsolete2;
+       u8 obsolete3;
+} __packed;
+
+struct bdb_lfp_backlight_data {
+       u8 entry_size;
+       struct bdb_lfp_backlight_data_entry data[16];
+       u8 level[16];
+} __packed;
+
 struct aimdb_header {
        char signature[16];
        char oem_device[20];