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authorNicolin Chen <nicoleotsuka@gmail.com>2018-09-29 14:44:07 -0700
committerGuenter Roeck <linux@roeck-us.net>2018-10-10 20:37:13 -0700
commit59d608e152e582604e384beebbd607686e4265cf (patch)
treec4d1af4f41dacaebecc4142cf7a906e87063be2e /drivers/hwmon
parent791ebc9d34e9d212fc03742c31654b017d385926 (diff)
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: Nicolin Chen <nicoleotsuka@gmail.com> [groeck: Moved call to dev_set_drvdata()] Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon')
-rw-r--r--drivers/hwmon/ina3221.c63
1 files changed, 63 insertions, 0 deletions
diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
index e0c4f4d83f4e..1e38b4c43fbf 100644
--- a/drivers/hwmon/ina3221.c
+++ b/drivers/hwmon/ina3221.c
@@ -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,
};