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hwmon: (ina3221) Add suspend and resume functions

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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: Nicolin Chen <nicoleotsuka@gmail.com>
[groeck: Moved call to dev_set_drvdata()]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Nicolin Chen 2018-09-29 14:44:07 -07:00 committed by Guenter Roeck
parent 791ebc9d34
commit 59d608e152
1 changed files with 63 additions and 0 deletions
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63
drivers/hwmon/ina3221.c
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@ -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,
};