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Commit 59d608e1 authored by Nicolin Chen's avatar Nicolin Chen Committed by Guenter Roeck
Browse files

hwmon: (ina3221) Add suspend and resume functions 



Depending on the hardware design, an INA3221 chip might lose
its power during system suspend/resume. So this patch adds
a set of suspend and resume functions to cache the register
values including config register value and limit settings.

Signed-off-by: default avatarNicolin Chen <nicoleotsuka@gmail.com>
[groeck: Moved call to dev_set_drvdata()]
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 791ebc9d

drivers/hwmon/ina3221.c

+63 −0
Original line number Diff line number Diff line
@@ -38,6 +38,8 @@ 
#define INA3221_WARN3			0x0c

#define INA3221_MASK_ENABLE		0x0f



#define INA3221_CONFIG_MODE_MASK	GENMASK(2, 0)

#define INA3221_CONFIG_MODE_POWERDOWN	0

#define INA3221_CONFIG_MODE_SHUNT	BIT(0)

#define INA3221_CONFIG_MODE_BUS		BIT(1)

#define INA3221_CONFIG_MODE_CONTINUOUS	BIT(2)
@@ -91,11 +93,13 @@ static const unsigned int register_channel[] = { 
 * @regmap: Register map of the device

 * @fields: Register fields of the device

 * @shunt_resistors: Array of resistor values per channel

 * @reg_config: Register value of INA3221_CONFIG

 */

struct ina3221_data {

	struct regmap *regmap;

	struct regmap_field *fields[F_MAX_FIELDS];

	int shunt_resistors[INA3221_NUM_CHANNELS];

	u32 reg_config;

};



static int ina3221_read_value(struct ina3221_data *ina, unsigned int reg,
@@ -407,6 +411,8 @@ static int ina3221_probe(struct i2c_client *client, 
		return ret;

	}



	dev_set_drvdata(dev, ina);



	hwmon_dev = devm_hwmon_device_register_with_groups(dev,

							   client->name,

							   ina, ina3221_groups);
@@ -418,6 +424,62 @@ static int ina3221_probe(struct i2c_client *client, 
	return 0;

}



#ifdef CONFIG_PM

static int ina3221_suspend(struct device *dev)

{

	struct ina3221_data *ina = dev_get_drvdata(dev);

	int ret;



	/* Save config register value and enable cache-only */

	ret = regmap_read(ina->regmap, INA3221_CONFIG, &ina->reg_config);

	if (ret)

		return ret;



	/* Set to power-down mode for power saving */

	ret = regmap_update_bits(ina->regmap, INA3221_CONFIG,

				 INA3221_CONFIG_MODE_MASK,

				 INA3221_CONFIG_MODE_POWERDOWN);

	if (ret)

		return ret;



	regcache_cache_only(ina->regmap, true);

	regcache_mark_dirty(ina->regmap);



	return 0;

}



static int ina3221_resume(struct device *dev)

{

	struct ina3221_data *ina = dev_get_drvdata(dev);

	int ret;



	regcache_cache_only(ina->regmap, false);



	/* Software reset the chip */

	ret = regmap_field_write(ina->fields[F_RST], true);

	if (ret) {

		dev_err(dev, "Unable to reset device\n");

		return ret;

	}



	/* Restore cached register values to hardware */

	ret = regcache_sync(ina->regmap);

	if (ret)

		return ret;



	/* Restore config register value to hardware */

	ret = regmap_write(ina->regmap, INA3221_CONFIG, ina->reg_config);

	if (ret)

		return ret;



	return 0;

}

#endif



static const struct dev_pm_ops ina3221_pm = {

	SET_SYSTEM_SLEEP_PM_OPS(ina3221_suspend, ina3221_resume)

};



static const struct of_device_id ina3221_of_match_table[] = {

	{ .compatible = "ti,ina3221", },

	{ /* sentinel */ }
@@ -435,6 +497,7 @@ static struct i2c_driver ina3221_i2c_driver = { 
	.driver = {

		.name = INA3221_DRIVER_NAME,

		.of_match_table = ina3221_of_match_table,

		.pm = &ina3221_pm,

	},

	.id_table = ina3221_ids,

};