Some touch controllers have to be powered on after the panel's backlight
is enabled. To support these controllers, introduce .panel_enabled() and
.panel_disabling() to panel_follower_funcs and use them to power on the
device after the panel and its backlight are enabled.
Signed-off-by: Pin-yen Lin <treapk...@chromium.org>
---
Changes in v3:
- Update kernel-docs of drm_panel_add_follower() and drm_panel_remove_follower()
- Fix the order of calling .panel_disabling() and .panel_unpreparing()
- Add a blank line before the goto label
Changes in v2:
- Replace after_panel_enabled flag with enabled/disabling callbacks
drivers/gpu/drm/drm_panel.c | 73 +++++++++++++++++++++++++++++++------
include/drm/drm_panel.h | 14 +++++++
2 files changed, 76 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c
index c8bb28dccdc1b..d1e6598ea3bc0 100644
--- a/drivers/gpu/drm/drm_panel.c
+++ b/drivers/gpu/drm/drm_panel.c
@@ -134,6 +134,9 @@ void drm_panel_prepare(struct drm_panel *panel)
panel->prepared = true;
list_for_each_entry(follower, &panel->followers, list) {
+ if (!follower->funcs->panel_prepared)
+ continue;
+
ret = follower->funcs->panel_prepared(follower);
if (ret < 0)
dev_info(panel->dev, "%ps failed: %d\n",
@@ -179,6 +182,9 @@ void drm_panel_unprepare(struct drm_panel *panel)
mutex_lock(&panel->follower_lock);
list_for_each_entry(follower, &panel->followers, list) {
+ if (!follower->funcs->panel_unpreparing)
+ continue;
+
ret = follower->funcs->panel_unpreparing(follower);
if (ret < 0)
dev_info(panel->dev, "%ps failed: %d\n",
@@ -209,6 +215,7 @@ EXPORT_SYMBOL(drm_panel_unprepare);
*/
void drm_panel_enable(struct drm_panel *panel)
{
+ struct drm_panel_follower *follower;
int ret;
if (!panel)
@@ -219,10 +226,12 @@ void drm_panel_enable(struct drm_panel *panel)
return;
}
+ mutex_lock(&panel->follower_lock);
+
if (panel->funcs && panel->funcs->enable) {
ret = panel->funcs->enable(panel);
if (ret < 0)
- return;
+ goto exit;
}
panel->enabled = true;
@@ -230,6 +239,19 @@ void drm_panel_enable(struct drm_panel *panel)
if (ret < 0)
DRM_DEV_INFO(panel->dev, "failed to enable backlight: %d\n",
ret);
+
+ list_for_each_entry(follower, &panel->followers, list) {
+ if (!follower->funcs->panel_enabled)
+ continue;
+
+ ret = follower->funcs->panel_enabled(follower);
+ if (ret < 0)
+ dev_info(panel->dev, "%ps failed: %d\n",
+ follower->funcs->panel_enabled, ret);
+ }
+
+exit:
+ mutex_unlock(&panel->follower_lock);
}
EXPORT_SYMBOL(drm_panel_enable);
@@ -243,6 +265,7 @@ EXPORT_SYMBOL(drm_panel_enable);
*/
void drm_panel_disable(struct drm_panel *panel)
{
+ struct drm_panel_follower *follower;
int ret;
if (!panel)
@@ -262,6 +285,18 @@ void drm_panel_disable(struct drm_panel *panel)
return;
}
+ mutex_lock(&panel->follower_lock);
+
+ list_for_each_entry(follower, &panel->followers, list) {
+ if (!follower->funcs->panel_disabling)
+ continue;
+
+ ret = follower->funcs->panel_disabling(follower);
+ if (ret < 0)
+ dev_info(panel->dev, "%ps failed: %d\n",
+ follower->funcs->panel_disabling, ret);
+ }
+
ret = backlight_disable(panel->backlight);
if (ret < 0)
DRM_DEV_INFO(panel->dev, "failed to disable backlight: %d\n",
@@ -270,9 +305,12 @@ void drm_panel_disable(struct drm_panel *panel)
if (panel->funcs && panel->funcs->disable) {
ret = panel->funcs->disable(panel);
if (ret < 0)
- return;
+ goto exit;
}
panel->enabled = false;
+
+exit:
+ mutex_unlock(&panel->follower_lock);
}
EXPORT_SYMBOL(drm_panel_disable);
@@ -539,13 +577,13 @@ EXPORT_SYMBOL(drm_is_panel_follower);
* @follower_dev: The 'struct device' for the follower.
* @follower: The panel follower descriptor for the follower.
*
- * A panel follower is called right after preparing the panel and right before
- * unpreparing the panel. It's primary intention is to power on an associated
- * touchscreen, though it could be used for any similar devices. Multiple
- * devices are allowed the follow the same panel.
+ * A panel follower is called right after preparing/enabling the panel and
right
+ * before unpreparing/disabling the panel. It's primary intention is to power
on
+ * an associated touchscreen, though it could be used for any similar devices.
+ * Multiple devices are allowed the follow the same panel.
*
- * If a follower is added to a panel that's already been turned on, the
- * follower's prepare callback is called right away.
+ * If a follower is added to a panel that's already been prepared/enabled, the
+ * follower's prepared/enabled callback is called right away.
*
* The "panel" property of the follower points to the panel to be followed.
*
@@ -569,12 +607,18 @@ int drm_panel_add_follower(struct device *follower_dev,
mutex_lock(&panel->follower_lock);
list_add_tail(&follower->list, &panel->followers);
- if (panel->prepared) {
+ if (panel->prepared && follower->funcs->panel_prepared) {
ret = follower->funcs->panel_prepared(follower);
if (ret < 0)
dev_info(panel->dev, "%ps failed: %d\n",
follower->funcs->panel_prepared, ret);
}
+ if (panel->enabled && follower->funcs->panel_enabled) {
+ ret = follower->funcs->panel_enabled(follower);
+ if (ret < 0)
+ dev_info(panel->dev, "%ps failed: %d\n",
+ follower->funcs->panel_enabled, ret);
+ }
mutex_unlock(&panel->follower_lock);
@@ -587,7 +631,8 @@ EXPORT_SYMBOL(drm_panel_add_follower);
* @follower: The panel follower descriptor for the follower.
*
* Undo drm_panel_add_follower(). This includes calling the follower's
- * unprepare function if we're removed from a panel that's currently prepared.
+ * unpreparing/disabling function if we're removed from a panel that's
currently
+ * prepared/enabled.
*
* Return: 0 or an error code.
*/
@@ -598,7 +643,13 @@ void drm_panel_remove_follower(struct drm_panel_follower
*follower)
mutex_lock(&panel->follower_lock);
- if (panel->prepared) {
+ if (panel->enabled && follower->funcs->panel_disabling) {
+ ret = follower->funcs->panel_disabling(follower);
+ if (ret < 0)
+ dev_info(panel->dev, "%ps failed: %d\n",
+ follower->funcs->panel_disabling, ret);
+ }
+ if (panel->prepared && follower->funcs->panel_unpreparing) {
ret = follower->funcs->panel_unpreparing(follower);
if (ret < 0)
dev_info(panel->dev, "%ps failed: %d\n",
diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h
index 843fb756a2950..2407bfa60236f 100644
--- a/include/drm/drm_panel.h
+++ b/include/drm/drm_panel.h
@@ -160,6 +160,20 @@ struct drm_panel_follower_funcs {
* Called before the panel is powered off.
*/
int (*panel_unpreparing)(struct drm_panel_follower *follower);
+
+ /**
+ * @panel_enabled:
+ *
+ * Called after the panel and the backlight have been enabled.
+ */
+ int (*panel_enabled)(struct drm_panel_follower *follower);
+
+ /**
+ * @panel_disabling:
+ *
+ * Called before the panel and the backlight are disabled.
+ */
+ int (*panel_disabling)(struct drm_panel_follower *follower);
};
struct drm_panel_follower {
--
2.51.0.rc1.163.g2494970778-goog
