3856bd3e5c3d2e2eb7bacc01ff79dda84981a557b48976705dfe945e.patch

From 10d3d5db48a377841ebd808d0bb8e47e83af4b90 Mon Sep 17 00:00:00 2001
From: Alex Deucher <alexander.deucher@amd.com>
Date: Tue, 11 May 2021 11:37:09 -0400
Subject: [PATCH] UPSTREAM: drm/amdgpu/display: add helper functions to get/set
 backlight (v2)

And cache the value.  These can be used by the backlight callbacks
and modesetting functions.

v2: rebase on latest backlight changes.

Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1337
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 3d6c91641bc8a883b0c810ac1a919db29ebd5ee7)
Signed-off-by: Sean Paul <seanpaul@chromium.org>

BUG=b:187300590
TEST=Tested with single/multiple displays, suspend/resume, hotplugs on volteer/trogdor/dedede/zork, build tested on amd64/arm64-generic

Change-Id: If793dfb57996cc3eaf15310664bf884183ab8022
---
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 42 ++++++++++++++-----
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h |  7 ++++
 2 files changed, 38 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 43297bda76c8..08ab12357a0b 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -3411,26 +3411,28 @@ static u32 convert_brightness_to_user(const struct amdgpu_dm_backlight_caps *cap
 				 max - min);
 }
 
-static int amdgpu_dm_backlight_update_status(struct backlight_device *bd)
+static int amdgpu_dm_backlight_set_level(struct amdgpu_display_manager *dm,
+					 u32 user_brightness)
 {
-	struct amdgpu_display_manager *dm = bl_get_data(bd);
 	struct amdgpu_dm_backlight_caps caps;
 	struct dc_link *link[AMDGPU_DM_MAX_NUM_EDP];
-	u32 brightness;
+	u32 brightness[AMDGPU_DM_MAX_NUM_EDP];
 	bool rc;
 	int i;
 
 	amdgpu_dm_update_backlight_caps(dm);
 	caps = dm->backlight_caps;
 
-	for (i = 0; i < dm->num_of_edps; i++)
+	for (i = 0; i < dm->num_of_edps; i++) {
+		dm->brightness[i] = user_brightness;
+		brightness[i] = convert_brightness_from_user(&caps, dm->brightness[i]);
 		link[i] = (struct dc_link *)dm->backlight_link[i];
+	}
 
-	brightness = convert_brightness_from_user(&caps, bd->props.brightness);
-	// Change brightness based on AUX property
+	/* Change brightness based on AUX property */
 	if (caps.aux_support) {
 		for (i = 0; i < dm->num_of_edps; i++) {
-			rc = dc_link_set_backlight_level_nits(link[i], true, brightness,
+			rc = dc_link_set_backlight_level_nits(link[i], true, brightness[i],
 				AUX_BL_DEFAULT_TRANSITION_TIME_MS);
 			if (!rc) {
 				DRM_ERROR("DM: Failed to update backlight via AUX on eDP[%d]\n", i);
@@ -3439,7 +3441,7 @@ static int amdgpu_dm_backlight_update_status(struct backlight_device *bd)
 		}
 	} else {
 		for (i = 0; i < dm->num_of_edps; i++) {
-			rc = dc_link_set_backlight_level(dm->backlight_link[i], brightness, 0);
+			rc = dc_link_set_backlight_level(dm->backlight_link[i], brightness[i], 0);
 			if (!rc) {
 				DRM_ERROR("DM: Failed to update backlight on eDP[%d]\n", i);
 				break;
@@ -3450,9 +3452,17 @@ static int amdgpu_dm_backlight_update_status(struct backlight_device *bd)
 	return rc ? 0 : 1;
 }
 
-static int amdgpu_dm_backlight_get_brightness(struct backlight_device *bd)
+static int amdgpu_dm_backlight_update_status(struct backlight_device *bd)
 {
 	struct amdgpu_display_manager *dm = bl_get_data(bd);
+
+	amdgpu_dm_backlight_set_level(dm, bd->props.brightness);
+
+	return 0;
+}
+
+static u32 amdgpu_dm_backlight_get_level(struct amdgpu_display_manager *dm)
+{
 	struct amdgpu_dm_backlight_caps caps;
 
 	amdgpu_dm_update_backlight_caps(dm);
@@ -3465,17 +3475,24 @@ static int amdgpu_dm_backlight_get_brightness(struct backlight_device *bd)
 
 		rc = dc_link_get_backlight_level_nits(link, &avg, &peak);
 		if (!rc)
-			return bd->props.brightness;
+			return dm->brightness[0];
 		return convert_brightness_to_user(&caps, avg);
 	} else {
 		int ret = dc_link_get_backlight_level(dm->backlight_link[0]);
 
 		if (ret == DC_ERROR_UNEXPECTED)
-			return bd->props.brightness;
+			return dm->brightness[0];
 		return convert_brightness_to_user(&caps, ret);
 	}
 }
 
+static int amdgpu_dm_backlight_get_brightness(struct backlight_device *bd)
+{
+	struct amdgpu_display_manager *dm = bl_get_data(bd);
+
+	return amdgpu_dm_backlight_get_level(dm);
+}
+
 static const struct backlight_ops amdgpu_dm_backlight_ops = {
 	.options = BL_CORE_SUSPENDRESUME,
 	.get_brightness = amdgpu_dm_backlight_get_brightness,
@@ -3487,8 +3504,11 @@ amdgpu_dm_register_backlight_device(struct amdgpu_display_manager *dm)
 {
 	char bl_name[16];
 	struct backlight_properties props = { 0 };
+	int i;
 
 	amdgpu_dm_update_backlight_caps(dm);
+	for (i = 0; i < dm->num_of_edps; i++)
+		dm->brightness[i] = AMDGPU_MAX_BL_LEVEL;
 
 	props.max_brightness = AMDGPU_MAX_BL_LEVEL;
 	props.brightness = AMDGPU_MAX_BL_LEVEL;
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
index a65ebe1518ae..1def0b693f1f 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
@@ -427,6 +427,13 @@ struct amdgpu_display_manager {
 	 * DAL fb memory allocation list, for communication with SMU.
 	 */
 	struct list_head da_list;
+
+	/**
+	 * @brightness:
+	 *
+	 * cached backlight values.
+	 */
+	u32 brightness[AMDGPU_DM_MAX_NUM_EDP];
 };
 
 enum dsc_clock_force_state {
-- 
2.17.1