[PATCH 5/6] drm/i915: parse backlight modulation frequency from the BIOS VBT

Rodrigo Vivi
2013-12-02T13:27:00Z

From: Jani Nikula <jani.nikula@intel.com>

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>
---
drivers/gpu/drm/i915/i915_drv.h | 5 +++++
drivers/gpu/drm/i915/intel_bios.c | 29 +++++++++++++++++++++++++++++
drivers/gpu/drm/i915/intel_bios.h | 16 ++++++++++++++++
3 files changed, 50 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 780f815..687eee2 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1185,6 +1185,11 @@ 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 e4fba39..720ce55 100644
--- 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
--- 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];
--
1.8.3.1