On 1/4/19 4:49 PM, Nicolin Chen wrote:
By default, ina3221, as a hardware monitor, continuously measures
the inputs and generates corresponding data. However, for battery
powered devices, this mode might be power consuming.
The DT binding doc is updated with a new boolean type property to
allow changing the default operating mode from consuming mode to
single-shot mode, which will measure input on demand and then shut
down to save power.
So this patch implements the DT property accordingly.
Signed-off-by: Nicolin Chen <nicoleotsuka@xxxxxxxxx>
---
drivers/hwmon/ina3221.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
index e90ccac8bebb..152735659e19 100644
--- a/drivers/hwmon/ina3221.c
+++ b/drivers/hwmon/ina3221.c
@@ -91,6 +91,12 @@ enum ina3221_channels {
INA3221_NUM_CHANNELS
};
+enum ina3221_modes {
+ INA3221_MODE_SINGLE_SHOT,
+ INA3221_MODE_CONTINUOUS,
+ INA3221_NUM_MODES,
Is NUM_MODES used anywhere ? Please drop unless there is a reason to keep it.
Guenter
+};
+
/**
* struct ina3221_input - channel input source specific information
* @label: label of channel input source
@@ -111,6 +117,7 @@ struct ina3221_input {
* @inputs: Array of channel input source specific structures
* @lock: mutex lock to serialize sysfs attribute accesses
* @reg_config: Register value of INA3221_CONFIG
+ * @mode: Operating mode -- continuous or single-shot
*/
struct ina3221_data {
struct device *pm_dev;
@@ -119,6 +126,7 @@ struct ina3221_data {
struct ina3221_input inputs[INA3221_NUM_CHANNELS];
struct mutex lock;
u32 reg_config;
+ enum ina3221_modes mode;
};
static inline bool ina3221_is_enabled(struct ina3221_data *ina, int channel)
@@ -188,6 +196,11 @@ static int ina3221_read_in(struct device *dev, u32 attr, int channel, long *val)
if (!ina3221_is_enabled(ina, channel))
return -ENODATA;
+ /* Write CONFIG register to trigger a single-shot measurement */
+ if (ina->mode == INA3221_MODE_SINGLE_SHOT)
+ regmap_write(ina->regmap, INA3221_CONFIG,
+ ina->reg_config);
+
ret = ina3221_wait_for_data(ina);
if (ret)
return ret;
@@ -232,6 +245,11 @@ static int ina3221_read_curr(struct device *dev, u32 attr,
if (!ina3221_is_enabled(ina, channel))
return -ENODATA;
+ /* Write CONFIG register to trigger a single-shot measurement */
+ if (ina->mode == INA3221_MODE_SINGLE_SHOT)
+ regmap_write(ina->regmap, INA3221_CONFIG,
+ ina->reg_config);
+
ret = ina3221_wait_for_data(ina);
if (ret)
return ret;
@@ -617,6 +635,9 @@ static int ina3221_probe_from_dt(struct device *dev, struct ina3221_data *ina)
if (!np)
return 0;
+ if (of_property_read_bool(np, "ti,single-shot"))
+ ina->mode = INA3221_MODE_SINGLE_SHOT;
+
for_each_child_of_node(np, child) {
ret = ina3221_probe_child_from_dt(dev, child, ina);
if (ret)
@@ -654,6 +675,9 @@ static int ina3221_probe(struct i2c_client *client,
}
}
+ /* Hardware default uses the continuous mode */
+ ina->mode = INA3221_MODE_CONTINUOUS;
+
for (i = 0; i < INA3221_NUM_CHANNELS; i++)
ina->inputs[i].shunt_resistor = INA3221_RSHUNT_DEFAULT;
@@ -666,6 +690,10 @@ static int ina3221_probe(struct i2c_client *client,
/* The driver will be reset, so use reset value */
ina->reg_config = INA3221_CONFIG_DEFAULT;
+ /* Clear continuous bit to use single-shot mode */
+ if (ina->mode == INA3221_MODE_SINGLE_SHOT)
+ ina->reg_config &= ~INA3221_CONFIG_MODE_CONTINUOUS;
+
/* Disable channels if their inputs are disconnected */
for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
if (ina->inputs[i].disconnected)
