msm: mdss: Add absolute backlight control for assertive display

Allow for assertive display to disable backlight updates (except for
updates to turn off display) as an option for automatic backlight mode. If
backlight updates are not prevented, flickering can occur when automatic
backlight mode is enabled and system tries to update backlight value due to
assertive display block controlling backlight values.

Change-Id: I250167e3387e3fbc795f7dfe9fc5f20398d6ca8c
Signed-off-by: Carl Vanderlip <carlv@codeaurora.org>
diff --git a/include/linux/msm_mdp.h b/include/linux/msm_mdp.h
index 2091ea5..18921a0 100644
--- a/include/linux/msm_mdp.h
+++ b/include/linux/msm_mdp.h
@@ -641,6 +641,8 @@
 	uint32_t *bl_lin_inv;
 };
 
+#define MDSS_AD_BL_CTRL_MODE_EN 1
+#define MDSS_AD_BL_CTRL_MODE_DIS 0
 struct mdss_ad_cfg {
 	uint32_t mode;
 	uint32_t al_calib_lut[33];
@@ -653,6 +655,7 @@
 	uint8_t strength_limit;
 	uint8_t t_filter_recursion;
 	uint16_t stab_itr;
+	uint32_t bl_ctrl_mode;
 };
 
 /* ops uses standard MDP_PP_* flags */