From 8bf9ed035bebd01fd89bb6eb1083e986c5d6f67c Mon Sep 17 00:00:00 2001
From: wengjun1 <wengjun1@motorola.com>
Date: Thu, 17 Oct 2019 14:02:52 +0800
Subject: [PATCH] Sofiap: Pen status notification to touch

- Because now we are using stylus on sofiap and this will keep
touch always on high sensitive mode which will easy to lead to
the problem such as ghost touch , residue points etc. So we add
a pen notifier to touch and then the firmware of the touch can adjust
the mode according to the status of the pen.

Change-Id: I328fbe973d960e0decc60b86e4d16140e66e2cb9
Signed-off-by: wengjun1 <wengjun1@motorola.com>
Reviewed-on: https://gerrit.mot.com/1438179
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Tested-by: Jira Key
Reviewed-by: Jianqiu Huang <huangjq9@motorola.com>
Reviewed-by: Huosheng Liao <liaohs@motorola.com>
Submit-Approved: Jira Key
---
 drivers/misc/pen/bu520xx_pen.c       | 47 ++++++++++++++++++++++++++++
 include/linux/pen_detection_notify.h | 25 +++++++++++++++
 2 files changed, 72 insertions(+)
 create mode 100644 include/linux/pen_detection_notify.h

diff --git a/drivers/misc/pen/bu520xx_pen.c b/drivers/misc/pen/bu520xx_pen.c
index 7593bc6ddd39..fd2a76a1d99e 100644
--- a/drivers/misc/pen/bu520xx_pen.c
+++ b/drivers/misc/pen/bu520xx_pen.c
@@ -19,6 +19,7 @@
 #include <asm/uaccess.h>
 #include <linux/of_gpio.h>
 #include <linux/irq.h>
+#include <linux/pen_detection_notify.h>
 #ifdef CONFIG_HAS_WAKELOCK
 #include <linux/wakelock.h>
 #else
@@ -69,6 +70,48 @@ static struct hall_sensor_str {
 	struct delayed_work hall_sensor_dowork;
 }* hall_sensor_dev;
 
+static BLOCKING_NOTIFIER_HEAD(pen_detection_notifier_list);
+
+/**
+ * pen_detection_register_client - register a client notifier
+ * @nb: notifier block to callback on events
+ *
+ * This function registers a notifier callback function
+ * to pen_detection_notifier_list, which would be called when
+ * the passive pen is inserted or pulled out.
+ */
+int pen_detection_register_client(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&pen_detection_notifier_list,
+						nb);
+}
+EXPORT_SYMBOL(pen_detection_register_client);
+
+/**
+ * pen_detection_unregister_client - unregister a client notifier
+ * @nb: notifier block to callback on events
+ *
+ * This function unregisters the callback function from
+ * pen_detection_notifier_list.
+ */
+int pen_detection_unregister_client(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_unregister(&pen_detection_notifier_list,
+						  nb);
+}
+EXPORT_SYMBOL(pen_detection_unregister_client);
+
+/**
+ * pen_detection_notifier_call_chain - notify clients of pen_detection_events
+ * @val: event PEN_DETECTION_INSERT or PEN_DETECTION_PULL
+ * @v: notifier data, inculde display pen detection event.
+ */
+static int pen_detection_notifier_call_chain(unsigned long val, void *v)
+{
+	return blocking_notifier_call_chain(&pen_detection_notifier_list, val,
+					    v);
+}
+
 //static void hall_sensor_shutdown(struct platform_device *pdev);
 int pen_connect(struct input_handler *handler, struct input_dev *dev, const struct input_device_id *id){
 	pen_dbg_func_in();
@@ -288,6 +331,10 @@ static void pen_report_function(struct work_struct *dat)
 	__pm_wakeup_event(&hall_sensor_dev->wake_lock, msecs_to_jiffies(3000));
 #endif
 
+	if(!hall_sensor_dev->status)
+		pen_detection_notifier_call_chain(PEN_DETECTION_INSERT, NULL);
+	else
+		pen_detection_notifier_call_chain(PEN_DETECTION_PULL, NULL);
 	pen_info("[%s] SW_pen report value = %d\n", DRIVER_NAME,!hall_sensor_dev->status);
 }
 
diff --git a/include/linux/pen_detection_notify.h b/include/linux/pen_detection_notify.h
new file mode 100644
index 000000000000..87f1898d5de9
--- /dev/null
+++ b/include/linux/pen_detection_notify.h
@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2019, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#ifndef _PEN_DETECTION_DRM_NOTIFY_H_
+#define _PEN_DETECTION_DRM_NOTIFY_H_
+
+#include <linux/notifier.h>
+
+/* The event of pen insertion */
+#define PEN_DETECTION_INSERT		0x01
+/* The event of pen pull-out */
+#define PEN_DETECTION_PULL		0x02
+
+int pen_detection_register_client(struct notifier_block *nb);
+int pen_detection_unregister_client(struct notifier_block *nb);
+#endif