[PATCH 1/2] hwmon: ina3221: Add power sysfs nodes

From: Nicolin Chen
Date: Wed Sep 26 2018 - 02:43:06 EST

The hwmon sysfs ABI supports powerX_input and powerX_crit. This
can ease user space programs who care more about power in total
than voltage or current individually.

So this patch adds these two sysfs nodes for INA3221 driver.

Signed-off-by: Nicolin Chen <nicoleotsuka@xxxxxxxxx>
---
Documentation/hwmon/ina3221 | 4 +
drivers/hwmon/ina3221.c | 145 ++++++++++++++++++++++++++++++++----
2 files changed, 133 insertions(+), 16 deletions(-)

diff --git a/Documentation/hwmon/ina3221 b/Documentation/hwmon/ina3221
index 2726038be5bd..6be64b553cd0 100644
--- a/Documentation/hwmon/ina3221
+++ b/Documentation/hwmon/ina3221
@@ -34,3 +34,7 @@ curr[123]_max Warning alert current(mA) setting, activates the
average is above this value.
curr[123]_max_alarm Warning alert current limit exceeded
in[456]_input Shunt voltage(uV) for channels 1, 2, and 3 respectively
+power[123]_input Power(uW) measurement channels
+power[123]_crit Critical alert power(uW) setting, activates the
+ corresponding alarm when the respective power
+ is above this value
diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
index ce4d1f55e9cd..5890a2da3bfe 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_BUS(x) (INA3221_BUS1 + ((x) << 1))
+
#define INA3221_CONFIG_MODE_SHUNT BIT(1)
#define INA3221_CONFIG_MODE_BUS BIT(2)
#define INA3221_CONFIG_MODE_CONTINUOUS BIT(3)
@@ -172,43 +174,50 @@ static ssize_t ina3221_show_shunt_voltage(struct device *dev,
return snprintf(buf, PAGE_SIZE, "%d\n", voltage_uv);
}

-static ssize_t ina3221_show_current(struct device *dev,
- struct device_attribute *attr, char *buf)
+static int __ina3221_show_current(struct ina3221_data *ina,
+ unsigned int reg, int *current_ma)
{
- struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
- struct ina3221_data *ina = dev_get_drvdata(dev);
- unsigned int reg = sd_attr->index;
unsigned int channel = register_channel[reg];
struct ina3221_input *input = &ina->inputs[channel];
int resistance_uo = input->shunt_resistor;
- int val, current_ma, voltage_nv, ret;
+ int val, voltage_nv, ret;

+ /* Read bus shunt voltage */
ret = ina3221_read_value(ina, reg, &val);
if (ret)
return ret;
+
+ /* LSB (4th bit) is 40 uV (40000 nV) */
voltage_nv = val * 40000;

- current_ma = DIV_ROUND_CLOSEST(voltage_nv, resistance_uo);
+ *current_ma = DIV_ROUND_CLOSEST(voltage_nv, resistance_uo);

- return snprintf(buf, PAGE_SIZE, "%d\n", current_ma);
+ return 0;
}

-static ssize_t ina3221_set_current(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
+static ssize_t ina3221_show_current(struct device *dev,
+ struct device_attribute *attr, char *buf)
{
struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
struct ina3221_data *ina = dev_get_drvdata(dev);
unsigned int reg = sd_attr->index;
- unsigned int channel = register_channel[reg];
- struct ina3221_input *input = &ina->inputs[channel];
- int resistance_uo = input->shunt_resistor;
- int val, current_ma, voltage_uv, ret;
+ int current_ma, ret;

- ret = kstrtoint(buf, 0, &current_ma);
+ ret = __ina3221_show_current(ina, reg, &current_ma);
if (ret)
return ret;

+ return snprintf(buf, PAGE_SIZE, "%d\n", current_ma);
+}
+
+static int __ina3221_set_current(struct ina3221_data *ina,
+ unsigned int reg, int current_ma)
+{
+ unsigned int channel = register_channel[reg];
+ struct ina3221_input *input = &ina->inputs[channel];
+ int resistance_uo = input->shunt_resistor;
+ int val, voltage_uv, ret;
+
/* clamp current */
current_ma = clamp_val(current_ma,
INT_MIN / resistance_uo,
@@ -226,6 +235,26 @@ static ssize_t ina3221_set_current(struct device *dev,
if (ret)
return ret;

+ return 0;
+}
+
+static ssize_t ina3221_set_current(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
+ struct ina3221_data *ina = dev_get_drvdata(dev);
+ unsigned int reg = sd_attr->index;
+ int current_ma, ret;
+
+ ret = kstrtoint(buf, 0, &current_ma);
+ if (ret)
+ return ret;
+
+ ret = __ina3221_set_current(ina, reg, current_ma);
+ if (ret)
+ return ret;
+
return count;
}

@@ -278,6 +307,68 @@ static ssize_t ina3221_show_alert(struct device *dev,
return snprintf(buf, PAGE_SIZE, "%d\n", regval);
}

+static ssize_t ina3221_show_power(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
+ struct ina3221_data *ina = dev_get_drvdata(dev);
+ unsigned int reg = sd_attr->index;
+ unsigned int channel = register_channel[reg];
+ unsigned int reg_bus = INA3221_BUS(channel);
+ int val, current_ma, voltage_mv, ret;
+ s64 power_uw;
+
+ /* Read bus voltage */
+ ret = ina3221_read_value(ina, reg_bus, &val);
+ if (ret)
+ return ret;
+
+ /* LSB (4th bit) is 8 mV */
+ voltage_mv = val * 8;
+
+ /* Read calculated current */
+ ret = __ina3221_show_current(ina, reg, &current_ma);
+ if (ret)
+ return ret;
+
+ power_uw = (s64)voltage_mv * current_ma;
+
+ return snprintf(buf, PAGE_SIZE, "%lld\n", power_uw);
+}
+
+static ssize_t ina3221_set_power(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
+ struct ina3221_data *ina = dev_get_drvdata(dev);
+ unsigned int reg = sd_attr->index;
+ unsigned int channel = register_channel[reg];
+ unsigned int reg_bus = INA3221_BUS(channel);
+ int val, current_ma, voltage_mv, ret;
+ s64 power_uw;
+
+ ret = kstrtos64(buf, 0, &power_uw);
+ if (ret)
+ return ret;
+
+ /* Read bus voltage */
+ ret = ina3221_read_value(ina, reg_bus, &val);
+ if (ret)
+ return ret;
+
+ /* LSB (4th bit) is 8 mV */
+ voltage_mv = val * 8;
+
+ current_ma = DIV_ROUND_CLOSEST(power_uw, voltage_mv);
+
+ ret = __ina3221_set_current(ina, reg, current_ma);
+ if (ret)
+ return ret;
+
+ return count;
+}
+
/* input channel label */
static SENSOR_DEVICE_ATTR(in1_label, 0444,
ina3221_show_label, NULL, INA3221_CHANNEL1);
@@ -350,6 +441,22 @@ static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO,
static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO,
ina3221_show_shunt_voltage, NULL, INA3221_SHUNT3);

+/* calculated power */
+static SENSOR_DEVICE_ATTR(power1_input, 0444,
+ ina3221_show_power, NULL, INA3221_SHUNT1);
+static SENSOR_DEVICE_ATTR(power2_input, 0444,
+ ina3221_show_power, NULL, INA3221_SHUNT2);
+static SENSOR_DEVICE_ATTR(power3_input, 0444,
+ ina3221_show_power, NULL, INA3221_SHUNT3);
+
+/* critical power */
+static SENSOR_DEVICE_ATTR(power1_crit, 0644,
+ ina3221_show_power, ina3221_set_power, INA3221_CRIT1);
+static SENSOR_DEVICE_ATTR(power2_crit, 0644,
+ ina3221_show_power, ina3221_set_power, INA3221_CRIT2);
+static SENSOR_DEVICE_ATTR(power3_crit, 0644,
+ ina3221_show_power, ina3221_set_power, INA3221_CRIT3);
+
static struct attribute *ina3221_attrs[] = {
/* channel 1 -- make sure label at first */
&sensor_dev_attr_in1_label.dev_attr.attr,
@@ -361,6 +468,8 @@ static struct attribute *ina3221_attrs[] = {
&sensor_dev_attr_curr1_max.dev_attr.attr,
&sensor_dev_attr_curr1_max_alarm.dev_attr.attr,
&sensor_dev_attr_in4_input.dev_attr.attr,
+ &sensor_dev_attr_power1_input.dev_attr.attr,
+ &sensor_dev_attr_power1_crit.dev_attr.attr,

/* channel 2 -- make sure label at first */
&sensor_dev_attr_in2_label.dev_attr.attr,
@@ -372,6 +481,8 @@ static struct attribute *ina3221_attrs[] = {
&sensor_dev_attr_curr2_max.dev_attr.attr,
&sensor_dev_attr_curr2_max_alarm.dev_attr.attr,
&sensor_dev_attr_in5_input.dev_attr.attr,
+ &sensor_dev_attr_power2_input.dev_attr.attr,
+ &sensor_dev_attr_power2_crit.dev_attr.attr,

/* channel 3 -- make sure label at first */
&sensor_dev_attr_in3_label.dev_attr.attr,
@@ -383,6 +494,8 @@ static struct attribute *ina3221_attrs[] = {
&sensor_dev_attr_curr3_max.dev_attr.attr,
&sensor_dev_attr_curr3_max_alarm.dev_attr.attr,
&sensor_dev_attr_in6_input.dev_attr.attr,
+ &sensor_dev_attr_power3_input.dev_attr.attr,
+ &sensor_dev_attr_power3_crit.dev_attr.attr,

NULL,
};
--
2.17.1