sensor: add hall sensor mh248 driver support

Change-Id: Idc8a068af8de06c058a2553d174b75166436a5ed
Signed-off-by: Bin Yang <yangbin@rock-chips.com>

drivers/input/sensors/hall/Kconfig

@@ -10,6 +10,10 @@ if HALL_DEVICE
 config HS_OCH165T
   bool "hall sensor och165t"
 	default y
-	
+
+config HS_MH248
+	bool "hall sensor mh248"
+	  default n
+
 endif
 

drivers/input/sensors/hall/Makefile

@@ -1 +1,2 @@
-obj-$(CONFIG_HS_OCH165T)  		+= och165t_hall.o
+obj-$(CONFIG_HS_OCH165T)  		+= och165t_hall.o
+obj-$(CONFIG_HS_MH248)  		+= mh248.o

drivers/input/sensors/hall/mh248.c

@@ -0,0 +1,174 @@
+ /*
+ * drivers/input/sensors/hall/mh248.c
+ *
+ * Copyright (C) 2012-2016 Rockchip Co.,Ltd.
+ * Author: Bin Yang <yangbin@rock-chips.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/irq.h>
+#include <linux/miscdevice.h>
+#include <linux/gpio.h>
+#include <linux/uaccess.h>
+#include <linux/atomic.h>
+#include <linux/delay.h>
+#include <linux/input.h>
+#include <linux/workqueue.h>
+#include <linux/freezer.h>
+#include <linux/of_gpio.h>
+#include <linux/sensor-dev.h>
+#include <linux/fb.h>
+#include <linux/notifier.h>
+
+struct mh248_para {
+	struct device *dev;
+	struct notifier_block fb_notif;
+	struct mutex ops_lock;
+	int is_suspend;
+	int gpio_pin;
+	int irq;
+	int active_value;
+};
+
+extern void rk_send_power_key(int state);
+extern void rk_send_wakeup_key(void);
+
+static int hall_fb_notifier_callback(struct notifier_block *self,
+				     unsigned long action, void *data)
+{
+	struct mh248_para *mh248;
+	struct fb_event *event = data;
+	int blank_mode = *((int *)event->data);
+
+	mh248 = container_of(self, struct mh248_para, fb_notif);
+
+	mutex_lock(&mh248->ops_lock);
+	if (action == FB_EARLY_EVENT_BLANK) {
+		switch (blank_mode) {
+		case FB_BLANK_UNBLANK:
+			break;
+		default:
+			mh248->is_suspend = 1;
+			break;
+		}
+	} else if (action == FB_EVENT_BLANK) {
+		switch (blank_mode) {
+		case FB_BLANK_UNBLANK:
+			mh248->is_suspend = 0;
+			break;
+		default:
+			break;
+		}
+	}
+	mutex_unlock(&mh248->ops_lock);
+
+	return NOTIFY_OK;
+}
+
+static irqreturn_t hall_mh248_interrupt(int irq, void *dev_id)
+{
+	struct mh248_para *mh248 = (struct mh248_para *)dev_id;
+	int gpio_value = 0;
+
+	gpio_value = gpio_get_value(mh248->gpio_pin);
+
+	if ((gpio_value != mh248->active_value) &&
+	    (mh248->is_suspend == 0)) {
+		rk_send_power_key(1);
+		rk_send_power_key(0);
+	} else if ((gpio_value == mh248->active_value) &&
+		   (mh248->is_suspend == 1)) {
+		rk_send_wakeup_key();
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int hall_mh248_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct mh248_para *mh248;
+	enum of_gpio_flags irq_flags;
+	int hallactive = 0;
+	int gpio_value = 0;
+	int ret = 0;
+
+	mh248 = devm_kzalloc(&pdev->dev, sizeof(*mh248), GFP_KERNEL);
+	if (!mh248)
+		return -ENOMEM;
+
+	mh248->dev = &pdev->dev;
+
+	mh248->gpio_pin = of_get_named_gpio_flags(np, "irq-gpio",
+					0, &irq_flags);
+	if (!gpio_is_valid(mh248->gpio_pin)) {
+		dev_err(mh248->dev, "Can not read property irq-gpio\n");
+		return mh248->gpio_pin;
+	}
+	mh248->irq = gpio_to_irq(mh248->gpio_pin);
+
+	of_property_read_u32(np, "hall-active", &hallactive);
+	mh248->active_value = hallactive;
+	mh248->is_suspend = 0;
+	mutex_init(&mh248->ops_lock);
+
+	ret = devm_gpio_request_one(mh248->dev, mh248->gpio_pin,
+				    GPIOF_DIR_IN, "hall_mh248");
+	if (ret < 0) {
+		dev_err(mh248->dev, "fail to request gpio:%d\n",
+			mh248->gpio_pin);
+		return ret;
+	}
+	gpio_value = gpio_get_value(mh248->gpio_pin);
+
+	ret = devm_request_threaded_irq(mh248->dev, mh248->irq,
+					NULL, hall_mh248_interrupt,
+					irq_flags | IRQF_NO_SUSPEND | IRQF_ONESHOT,
+					"hall_mh248", mh248);
+	if (ret < 0) {
+		dev_err(mh248->dev, "request irq(%d) failed, ret=%d\n",
+			mh248->irq, ret);
+		return ret;
+	}
+
+	enable_irq_wake(mh248->irq);
+	mh248->fb_notif.notifier_call = hall_fb_notifier_callback;
+	fb_register_client(&mh248->fb_notif);
+	dev_info(mh248->dev, "hall_mh248_probe success.\n");
+
+	return 0;
+}
+
+static const struct of_device_id hall_mh248_match[] = {
+	{ .compatible = "hall-mh248" },
+	{ /* Sentinel */ }
+};
+
+static struct platform_driver hall_mh248_driver = {
+	.probe = hall_mh248_probe,
+	.driver = {
+		.name = "mh248",
+		.owner = THIS_MODULE,
+		.of_match_table	= hall_mh248_match,
+	},
+};
+
+module_platform_driver(hall_mh248_driver);
+
+MODULE_ALIAS("platform:mh248");
+MODULE_AUTHOR("Bin Yang <yangbin@rock-chips.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Hall Sensor MH248 driver");