1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 363f66ca5d33..f39ac3a0fa93 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -1566,7 +1566,17 @@
 
 /* Backlight control */
 #define BLC_PWM_CTL             0x61254
+#define   BACKLIGHT_MODULATION_FREQ_SHIFT               (17)
 #define BLC_PWM_CTL2            0x61250 /* 965+ only */
+#define   BLM_COMBINATION_MODE (1 << 30)
+/*
+ * This is the most significant 15 bits of the number of backlight cycles in a
+ * complete cycle of the modulated backlight control.
+ *
+ * The actual value is this field multiplied by two.
+ */
+#define   BACKLIGHT_MODULATION_FREQ_MASK                (0x7fff << 17)
+#define   BLM_LEGACY_MODE                               (1 << 16)
 /*
  * This is the number of cycles out of the backlight modulation cycle for which
  * the backlight is on.