From 50497409761daa7041f7502ed5f49d3fc56b80af Mon Sep 17 00:00:00 2001
From: shengfei Xu <xsf@rock-chips.com>
Date: Mon, 11 Jan 2021 10:10:08 +0000
Subject: [PATCH] regulator: fan53555: support reboot

Fixes: 91c0d689ea8a ("Revert "regulator: fan53555: support reboot"")
Signed-off-by: shengfei Xu <xsf@rock-chips.com>
Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
Change-Id: I143fc44f49c95f01248c72a8f48282bf984b826b
---
 drivers/regulator/fan53555.c | 42 +++++++++++++++++++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/drivers/regulator/fan53555.c b/drivers/regulator/fan53555.c
index e00dd5ae52b8..9ed748d603f6 100644
--- a/drivers/regulator/fan53555.c
+++ b/drivers/regulator/fan53555.c
@@ -29,6 +29,7 @@
 #define TCS4525_VSEL1		0x10
 #define TCS4525_TIME		0x13
 #define TCS4525_COMMAND		0x14
+#define TCS4525_LIMCONF		0x16
 
 /* Control register */
 #define FAN53555_CONTROL	0x02
@@ -109,6 +110,7 @@ enum {
 
 struct fan53555_device_info {
 	enum fan53555_vendor vendor;
+	struct regmap *regmap;
 	struct device *dev;
 	struct regulator_desc desc;
 	struct regulator_init_data *regulator;
@@ -635,6 +637,7 @@ static int fan53555_regulator_probe(struct i2c_client *client,
 		dev_err(&client->dev, "Failed to allocate regmap!\n");
 		return PTR_ERR(regmap);
 	}
+	di->regmap = regmap;
 	di->dev = &client->dev;
 	i2c_set_clientdata(client, di);
 	/* Get chip ID */
@@ -669,8 +672,44 @@ static int fan53555_regulator_probe(struct i2c_client *client,
 	ret = fan53555_regulator_register(di, &config);
 	if (ret < 0)
 		dev_err(&client->dev, "Failed to register regulator!\n");
-	return ret;
 
+	return ret;
+}
+
+static void fan53555_regulator_shutdown(struct i2c_client *client)
+{
+	struct fan53555_device_info *di;
+	int ret;
+
+	di = i2c_get_clientdata(client);
+
+	dev_info(di->dev, "fan53555..... reset\n");
+
+	switch (di->vendor) {
+	case FAN53555_VENDOR_FAIRCHILD:
+	case FAN53555_VENDOR_SILERGY:
+		ret = regmap_update_bits(di->regmap, di->slew_reg,
+					 CTL_RESET, CTL_RESET);
+		break;
+	case FAN53526_VENDOR_TCS:
+		ret = regmap_update_bits(di->regmap, TCS4525_LIMCONF,
+					 CTL_RESET, CTL_RESET);
+		/*
+		 * the device can't return 'ack' during the reset,
+		 * it will return -ENXIO, ignore this error.
+		 */
+		if (ret == -ENXIO)
+			ret = 0;
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	if (ret < 0)
+		dev_err(di->dev, "reset: force fan53555_reset error! ret=%d\n", ret);
+	else
+		dev_info(di->dev, "reset: force fan53555_reset ok!\n");
 }
 
 static const struct i2c_device_id fan53555_id[] = {
@@ -703,6 +742,7 @@ static struct i2c_driver fan53555_regulator_driver = {
 		.of_match_table = of_match_ptr(fan53555_dt_ids),
 	},
 	.probe = fan53555_regulator_probe,
+	.shutdown = fan53555_regulator_shutdown,
 	.id_table = fan53555_id,
 };