mfd: rk808: Set only resetting pmic register for 817&809.

If the system needs hold register values when system will reboot.
need to set only resetting pmic register for 817&809 forcedly.

Change-Id: Ib4b850c86ec3079cd7e374bc96460ee1532854a2
Signed-off-by: Tony Xie <tony.xie@rock-chips.com>

Author: TonyXie06

drivers/mfd/rk808.c

@@ -1,7 +1,7 @@
 /*
  * MFD core driver for Rockchip RK808
  *
- * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
+ * Copyright (c) 2014-2018, Fuzhou Rockchip Electronics Co., Ltd
  *
  * Author: Chris Zhong <zyw@rock-chips.com>
  * Author: Zhang Qing <zhangqing@rock-chips.com>
@@ -24,6 +24,7 @@
 #include <linux/mfd/core.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
+#include <linux/reboot.h>
 #include <linux/regmap.h>
 #include <linux/syscore_ops.h>
 
@@ -1029,11 +1030,44 @@ static int rk817_pinctrl_init(struct device *dev, struct rk808 *rk808)
 	return 0;
 }
 
-static void rk817_of_property_prepare(struct regmap *regmap, struct device *dev)
+struct rk817_reboot_data_t {
+	struct rk808 *rk808;
+	struct notifier_block reboot_notifier;
+};
+
+static struct rk817_reboot_data_t rk817_reboot_data;
+
+static int rk817_reboot_notifier_handler(struct notifier_block *nb,
+					 unsigned long action, void *cmd)
+{
+	struct rk817_reboot_data_t *data;
+	int ret;
+	struct device *dev;
+
+	if (action != SYS_RESTART)
+		return NOTIFY_OK;
+
+	if (!cmd || !strlen(cmd) || !strcmp(cmd, "normal"))
+		return NOTIFY_OK;
+
+	data = container_of(nb, struct rk817_reboot_data_t, reboot_notifier);
+	dev = &data->rk808->i2c->dev;
+
+	ret = regmap_update_bits(data->rk808->regmap, RK817_SYS_CFG(3),
+				 RK817_RST_FUNC_MSK, RK817_RST_FUNC_REG);
+	if (ret)
+		dev_err(dev, "reboot: force RK817_RST_FUNC_REG error!\n");
+	else
+		dev_info(dev, "reboot: force RK817_RST_FUNC_REG ok!\n");
+	return NOTIFY_OK;
+}
+
+static void rk817_of_property_prepare(struct rk808 *rk808, struct device *dev)
 {
 	u32 inner;
 	int ret, func, msk, val;
 	struct device_node *np = dev->of_node;
+	struct regmap *regmap = rk808->regmap;
 
 	ret = of_property_read_u32_index(np, "fb-inner-reg-idxs", 0, &inner);
 	if (!ret && inner == RK817_ID_DCDC3)
@@ -1061,6 +1095,15 @@ static void rk817_of_property_prepare(struct regmap *regmap, struct device *dev)
 	regmap_update_bits(regmap, RK817_SYS_CFG(3), msk, val);
 
 	dev_info(dev, "support pmic reset mode:%d,%d\n", ret, func);
+
+	if (val & RK817_RST_FUNC_REG)
+		return;
+	rk817_reboot_data.rk808 = rk808;
+	rk817_reboot_data.reboot_notifier.notifier_call =
+		rk817_reboot_notifier_handler;
+	ret = register_reboot_notifier(&rk817_reboot_data.reboot_notifier);
+	if (ret)
+		dev_err(dev, "failed to register reboot nb\n");
 }
 
 static struct kobject *rk8xx_kobj;
@@ -1095,7 +1138,7 @@ static int rk808_probe(struct i2c_client *client,
 	int ret, i, pm_off = 0;
 	unsigned int on, off;
 	u8 pmic_id_msb = RK808_ID_MSB, pmic_id_lsb = RK808_ID_LSB;
-	void (*of_property_prepare_fn)(struct regmap *regmap,
+	void (*of_property_prepare_fn)(struct rk808 *rk808,
 				       struct device *dev) = NULL;
 	int (*pinctrl_init)(struct device *dev, struct rk808 *rk808) = NULL;
 
@@ -1246,7 +1289,7 @@ static int rk808_probe(struct i2c_client *client,
 	}
 
 	if (of_property_prepare_fn)
-		of_property_prepare_fn(rk808->regmap, &client->dev);
+		of_property_prepare_fn(rk808, &client->dev);
 
 	i2c_set_clientdata(client, rk808);
 	rk808->i2c = client;