[PATCH v9 3/4] misc: eeprom: at24: support pm_runtime control

[Bibby Hsieh <bibby.hsieh@mediatek.com>]

Although in the most platforms, the power of eeprom are alway
on, some platforms disable the eeprom power in order to meet
low power request. This patch add the pm_runtime ops to control
power to support all platforms.

Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
---
 drivers/misc/eeprom/at24.c | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 0681d5fdd538..6ba23a7e4da1 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -22,6 +22,7 @@
 #include <linux/nvmem-provider.h>
 #include <linux/regmap.h>
 #include <linux/pm_runtime.h>
+#include <linux/regulator/consumer.h>
 #include <linux/gpio/consumer.h>
 
 /* Address pointer is 16 bit. */
@@ -91,6 +92,7 @@ struct at24_data {
 
 	struct gpio_desc *wp_gpio;
 
+	struct regulator *vcc_reg;
 	/*
 	 * Some chips tie up multiple I2C addresses; dummy devices reserve
 	 * them for us, and we'll use them with SMBus calls.
@@ -662,6 +664,10 @@ static int at24_probe(struct i2c_client *client)
 	at24->client[0].client = client;
 	at24->client[0].regmap = regmap;
 
+	at24->vcc_reg = devm_regulator_get(dev, "vcc");
+	if (IS_ERR(at24->vcc_reg))
+		return PTR_ERR(at24->vcc_reg);
+
 	at24->wp_gpio = devm_gpiod_get_optional(dev, "wp", GPIOD_OUT_HIGH);
 	if (IS_ERR(at24->wp_gpio))
 		return PTR_ERR(at24->wp_gpio);
@@ -701,6 +707,12 @@ static int at24_probe(struct i2c_client *client)
 
 	i2c_set_clientdata(client, at24);
 
+	err = regulator_enable(at24->vcc_reg);
+	if (err) {
+		dev_err(dev, "Failed to enable vcc regulator\n");
+		return err;
+	}
+
 	/* enable runtime pm */
 	pm_runtime_set_active(dev);
 	pm_runtime_enable(dev);
@@ -713,6 +725,7 @@ static int at24_probe(struct i2c_client *client)
 	pm_runtime_idle(dev);
 	if (err) {
 		pm_runtime_disable(dev);
+		regulator_disable(at24->vcc_reg);
 		return -ENODEV;
 	}
 
@@ -729,14 +742,39 @@ static int at24_probe(struct i2c_client *client)
 static int at24_remove(struct i2c_client *client)
 {
 	pm_runtime_disable(&client->dev);
+	if (!pm_runtime_status_suspended(&client->dev))
+		regulator_disable(at24->vcc_reg);
 	pm_runtime_set_suspended(&client->dev);
 
 	return 0;
 }
 
+static int __maybe_unused at24_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct at24_data *at24 = i2c_get_clientdata(client);
+
+	return regulator_disable(at24->vcc_reg);
+}
+
+static int __maybe_unused at24_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct at24_data *at24 = i2c_get_clientdata(client);
+
+	return regulator_enable(at24->vcc_reg);
+}
+
+static const struct dev_pm_ops at24_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
+	SET_RUNTIME_PM_OPS(at24_suspend, at24_resume, NULL)
+};
+
 static struct i2c_driver at24_driver = {
 	.driver = {
 		.name = "at24",
+		.pm = &at24_pm_ops,
 		.of_match_table = at24_of_match,
 		.acpi_match_table = ACPI_PTR(at24_acpi_ids),
 	},
-- 
2.18.0