From 3c8a7d12dee6db25100a2035fd559ff7e38cbf56 Mon Sep 17 00:00:00 2001
From: Shashank Babu Chinta Venkata <sbchin@codeaurora.org>
Date: Wed, 16 Oct 2019 10:56:43 -0700
Subject: [PATCH] ANDROID: driver: gpu: drm: add notifier for panel related
 events

Add support for notfier of panel blank/unblank events.
This allows external drivers such as touch, backlight
drivers etc to subscribe to panel related events.

Signed-off-by: Shashank Babu Chinta Venkata <sbchin@codeaurora.org>
Bug: 139653858
Change-Id: I3ac644c1c931b959a511ee4a999a417a4b7bdcd1
---
 drivers/gpu/drm/drm_panel.c | 22 ++++++++++++++++++++++
 include/drm/drm_connector.h |  9 +++++++++
 include/drm/drm_panel.h     | 31 +++++++++++++++++++++++++++++++
 3 files changed, 62 insertions(+)

diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c
index 1d9a9d2fe0e0..a561ad15edea 100644
--- a/drivers/gpu/drm/drm_panel.c
+++ b/drivers/gpu/drm/drm_panel.c
@@ -48,6 +48,7 @@ static LIST_HEAD(panel_list);
 void drm_panel_init(struct drm_panel *panel)
 {
 	INIT_LIST_HEAD(&panel->list);
+	BLOCKING_INIT_NOTIFIER_HEAD(&panel->nh);
 }
 EXPORT_SYMBOL(drm_panel_init);
 
@@ -169,6 +170,27 @@ struct drm_panel *of_drm_find_panel(const struct device_node *np)
 EXPORT_SYMBOL(of_drm_find_panel);
 #endif
 
+int drm_panel_notifier_register(struct drm_panel *panel,
+	struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&panel->nh, nb);
+}
+EXPORT_SYMBOL(drm_panel_notifier_register);
+
+int drm_panel_notifier_unregister(struct drm_panel *panel,
+	struct notifier_block *nb)
+{
+	return blocking_notifier_chain_unregister(&panel->nh, nb);
+}
+EXPORT_SYMBOL(drm_panel_notifier_unregister);
+
+int drm_panel_notifier_call_chain(struct drm_panel *panel,
+	unsigned long val, void *v)
+{
+	return blocking_notifier_call_chain(&panel->nh, val, v);
+}
+EXPORT_SYMBOL(drm_panel_notifier_call_chain);
+
 MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
 MODULE_DESCRIPTION("DRM panel infrastructure");
 MODULE_LICENSE("GPL and additional rights");
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index cce2001c1407..7e067d09ccea 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -39,6 +39,7 @@ struct drm_encoder;
 struct drm_property;
 struct drm_property_blob;
 struct drm_printer;
+struct drm_panel;
 struct edid;
 
 enum drm_connector_force {
@@ -497,6 +498,7 @@ struct drm_connector_state {
 	struct drm_writeback_job *writeback_job;
 
 	/**
+
 	 * @hdr_output_metadata:
 	 * DRM blob property for HDR output metadata
 	 */
@@ -1174,6 +1176,13 @@ struct drm_connector {
 	/* HDR metdata */
 	struct hdr_output_metadata hdr_output_metadata;
 	struct hdr_sink_metadata hdr_sink_metadata;
+
+	/**
+	 * @panel:
+	 *
+	 * Can find the panel which connected to drm_connector.
+	 */
+	struct drm_panel *panel;
 };
 
 #define obj_to_connector(x) container_of(x, struct drm_connector, base)
diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h
index 675aa1e876ce..8e874b67e201 100644
--- a/include/drm/drm_panel.h
+++ b/include/drm/drm_panel.h
@@ -27,6 +27,23 @@
 #include <linux/err.h>
 #include <linux/errno.h>
 #include <linux/list.h>
+#include <linux/notifier.h>
+
+/* A hardware display blank change occurred */
+#define DRM_PANEL_EVENT_BLANK		0x01
+/* A hardware display blank early change occurred */
+#define DRM_PANEL_EARLY_EVENT_BLANK	0x02
+
+enum {
+	/* panel: power on */
+	DRM_PANEL_BLANK_UNBLANK,
+	/* panel: power off */
+	DRM_PANEL_BLANK_POWERDOWN,
+};
+
+struct drm_panel_notifier {
+	void *data;
+};
 
 struct device_node;
 struct drm_connector;
@@ -94,6 +111,13 @@ struct drm_panel {
 	const struct drm_panel_funcs *funcs;
 
 	struct list_head list;
+
+	/**
+	 * @nh:
+	 *
+	 * panel notifier list head
+	 */
+	struct blocking_notifier_head nh;
 };
 
 /**
@@ -195,6 +219,13 @@ void drm_panel_remove(struct drm_panel *panel);
 int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector);
 int drm_panel_detach(struct drm_panel *panel);
 
+int drm_panel_notifier_register(struct drm_panel *panel,
+	struct notifier_block *nb);
+int drm_panel_notifier_unregister(struct drm_panel *panel,
+	struct notifier_block *nb);
+int drm_panel_notifier_call_chain(struct drm_panel *panel,
+	unsigned long val, void *v);
+
 #if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL)
 struct drm_panel *of_drm_find_panel(const struct device_node *np);
 #else