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>

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 6368961..8a27666 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -3467,26 +3467,28 @@ 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);
@@ -3495,7 +3497,7 @@ 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;
@@ -3506,9 +3508,17 @@ 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);
@@ -3521,17 +3531,24 @@ 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,
@@ -3543,8 +3560,11 @@ 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 c6f79c7..721c8b4 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
@@ -436,6 +436,13 @@ struct amdgpu_display_manager {
         */
        struct list_head da_list;
        struct completion dmub_aux_transfer_done;
+
+       /**
+        * @brightness:
+        *
+        * cached backlight values.
+        */
+       u32 brightness[AMDGPU_DM_MAX_NUM_EDP];
 };
 
 enum dsc_clock_force_state {