hwmon: (ina2xx) Implement alert functions
Implement alert functions for INA226, INA230 and INA231. Expose 06h
Mask/Enable and 07h Alert Limit registers via alert setting and alarm
files.
Signed-off-by: Alex Qiu <xqiu@google.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
diff --git a/Documentation/hwmon/ina2xx.rst b/Documentation/hwmon/ina2xx.rst
index 94b9a26..ed81f54 100644
--- a/Documentation/hwmon/ina2xx.rst
+++ b/Documentation/hwmon/ina2xx.rst
@@ -99,6 +99,25 @@
------------------------------------------------
======================= ====================================================
+in0_lcrit Critical low shunt voltage
+in0_crit Critical high shunt voltage
+in0_lcrit_alarm Shunt voltage critical low alarm
+in0_crit_alarm Shunt voltage critical high alarm
+in1_lcrit Critical low bus voltage
+in1_crit Critical high bus voltage
+in1_lcrit_alarm Bus voltage critical low alarm
+in1_crit_alarm Bus voltage critical high alarm
+power1_crit Critical high power
+power1_crit_alarm Power critical high alarm
update_interval data conversion time; affects number of samples used
to average results for shunt and bus voltages.
======================= ====================================================
+
+.. note::
+
+ - Configure `shunt_resistor` before configure `power1_crit`, because power
+ value is calculated based on `shunt_resistor` set.
+ - Because of the underlying register implementation, only one `*crit` setting
+ and its `alarm` can be active. Writing to one `*crit` setting clears other
+ `*crit` settings and alarms. Writing 0 to any `*crit` setting clears all
+ `*crit` settings and alarms.
diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index e9e78c0..55d474e 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -74,6 +74,17 @@
#define INA226_READ_AVG(reg) (((reg) & INA226_AVG_RD_MASK) >> 9)
#define INA226_SHIFT_AVG(val) ((val) << 9)
+/* bit number of alert functions in Mask/Enable Register */
+#define INA226_SHUNT_OVER_VOLTAGE_BIT 15
+#define INA226_SHUNT_UNDER_VOLTAGE_BIT 14
+#define INA226_BUS_OVER_VOLTAGE_BIT 13
+#define INA226_BUS_UNDER_VOLTAGE_BIT 12
+#define INA226_POWER_OVER_LIMIT_BIT 11
+
+/* bit mask for alert config bits of Mask/Enable Register */
+#define INA226_ALERT_CONFIG_MASK 0xFC00
+#define INA226_ALERT_FUNCTION_FLAG BIT(4)
+
/* common attrs, ina226 attrs and NULL */
#define INA2XX_MAX_ATTRIBUTE_GROUPS 3
@@ -303,6 +314,145 @@ static ssize_t ina2xx_value_show(struct device *dev,
ina2xx_get_value(data, attr->index, regval));
}
+static int ina226_reg_to_alert(struct ina2xx_data *data, u8 bit, u16 regval)
+{
+ int reg;
+
+ switch (bit) {
+ case INA226_SHUNT_OVER_VOLTAGE_BIT:
+ case INA226_SHUNT_UNDER_VOLTAGE_BIT:
+ reg = INA2XX_SHUNT_VOLTAGE;
+ break;
+ case INA226_BUS_OVER_VOLTAGE_BIT:
+ case INA226_BUS_UNDER_VOLTAGE_BIT:
+ reg = INA2XX_BUS_VOLTAGE;
+ break;
+ case INA226_POWER_OVER_LIMIT_BIT:
+ reg = INA2XX_POWER;
+ break;
+ default:
+ /* programmer goofed */
+ WARN_ON_ONCE(1);
+ return 0;
+ }
+
+ return ina2xx_get_value(data, reg, regval);
+}
+
+/*
+ * Turns alert limit values into register values.
+ * Opposite of the formula in ina2xx_get_value().
+ */
+static s16 ina226_alert_to_reg(struct ina2xx_data *data, u8 bit, int val)
+{
+ switch (bit) {
+ case INA226_SHUNT_OVER_VOLTAGE_BIT:
+ case INA226_SHUNT_UNDER_VOLTAGE_BIT:
+ val *= data->config->shunt_div;
+ return clamp_val(val, SHRT_MIN, SHRT_MAX);
+ case INA226_BUS_OVER_VOLTAGE_BIT:
+ case INA226_BUS_UNDER_VOLTAGE_BIT:
+ val = (val * 1000) << data->config->bus_voltage_shift;
+ val = DIV_ROUND_CLOSEST(val, data->config->bus_voltage_lsb);
+ return clamp_val(val, 0, SHRT_MAX);
+ case INA226_POWER_OVER_LIMIT_BIT:
+ val = DIV_ROUND_CLOSEST(val, data->power_lsb_uW);
+ return clamp_val(val, 0, USHRT_MAX);
+ default:
+ /* programmer goofed */
+ WARN_ON_ONCE(1);
+ return 0;
+ }
+}
+
+static ssize_t ina226_alert_show(struct device *dev,
+ struct device_attribute *da, char *buf)
+{
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+ struct ina2xx_data *data = dev_get_drvdata(dev);
+ int regval;
+ int val = 0;
+ int ret;
+
+ mutex_lock(&data->config_lock);
+ ret = regmap_read(data->regmap, INA226_MASK_ENABLE, ®val);
+ if (ret)
+ goto abort;
+
+ if (regval & BIT(attr->index)) {
+ ret = regmap_read(data->regmap, INA226_ALERT_LIMIT, ®val);
+ if (ret)
+ goto abort;
+ val = ina226_reg_to_alert(data, attr->index, regval);
+ }
+
+ ret = snprintf(buf, PAGE_SIZE, "%d\n", val);
+abort:
+ mutex_unlock(&data->config_lock);
+ return ret;
+}
+
+static ssize_t ina226_alert_store(struct device *dev,
+ struct device_attribute *da,
+ const char *buf, size_t count)
+{
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+ struct ina2xx_data *data = dev_get_drvdata(dev);
+ unsigned long val;
+ int ret;
+
+ ret = kstrtoul(buf, 10, &val);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * Clear all alerts first to avoid accidentally triggering ALERT pin
+ * due to register write sequence. Then, only enable the alert
+ * if the value is non-zero.
+ */
+ mutex_lock(&data->config_lock);
+ ret = regmap_update_bits(data->regmap, INA226_MASK_ENABLE,
+ INA226_ALERT_CONFIG_MASK, 0);
+ if (ret < 0)
+ goto abort;
+
+ ret = regmap_write(data->regmap, INA226_ALERT_LIMIT,
+ ina226_alert_to_reg(data, attr->index, val));
+ if (ret < 0)
+ goto abort;
+
+ if (val != 0) {
+ ret = regmap_update_bits(data->regmap, INA226_MASK_ENABLE,
+ INA226_ALERT_CONFIG_MASK,
+ BIT(attr->index));
+ if (ret < 0)
+ goto abort;
+ }
+
+ ret = count;
+abort:
+ mutex_unlock(&data->config_lock);
+ return ret;
+}
+
+static ssize_t ina226_alarm_show(struct device *dev,
+ struct device_attribute *da, char *buf)
+{
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+ struct ina2xx_data *data = dev_get_drvdata(dev);
+ int regval;
+ int alarm = 0;
+ int ret;
+
+ ret = regmap_read(data->regmap, INA226_MASK_ENABLE, ®val);
+ if (ret)
+ return ret;
+
+ alarm = (regval & BIT(attr->index)) &&
+ (regval & INA226_ALERT_FUNCTION_FLAG);
+ return snprintf(buf, PAGE_SIZE, "%d\n", alarm);
+}
+
/*
* In order to keep calibration register value fixed, the product
* of current_lsb and shunt_resistor should also be fixed and equal
@@ -392,15 +542,38 @@ static ssize_t ina226_interval_show(struct device *dev,
/* shunt voltage */
static SENSOR_DEVICE_ATTR_RO(in0_input, ina2xx_value, INA2XX_SHUNT_VOLTAGE);
+/* shunt voltage over/under voltage alert setting and alarm */
+static SENSOR_DEVICE_ATTR_RW(in0_crit, ina226_alert,
+ INA226_SHUNT_OVER_VOLTAGE_BIT);
+static SENSOR_DEVICE_ATTR_RW(in0_lcrit, ina226_alert,
+ INA226_SHUNT_UNDER_VOLTAGE_BIT);
+static SENSOR_DEVICE_ATTR_RO(in0_crit_alarm, ina226_alarm,
+ INA226_SHUNT_OVER_VOLTAGE_BIT);
+static SENSOR_DEVICE_ATTR_RO(in0_lcrit_alarm, ina226_alarm,
+ INA226_SHUNT_UNDER_VOLTAGE_BIT);
/* bus voltage */
static SENSOR_DEVICE_ATTR_RO(in1_input, ina2xx_value, INA2XX_BUS_VOLTAGE);
+/* bus voltage over/under voltage alert setting and alarm */
+static SENSOR_DEVICE_ATTR_RW(in1_crit, ina226_alert,
+ INA226_BUS_OVER_VOLTAGE_BIT);
+static SENSOR_DEVICE_ATTR_RW(in1_lcrit, ina226_alert,
+ INA226_BUS_UNDER_VOLTAGE_BIT);
+static SENSOR_DEVICE_ATTR_RO(in1_crit_alarm, ina226_alarm,
+ INA226_BUS_OVER_VOLTAGE_BIT);
+static SENSOR_DEVICE_ATTR_RO(in1_lcrit_alarm, ina226_alarm,
+ INA226_BUS_UNDER_VOLTAGE_BIT);
/* calculated current */
static SENSOR_DEVICE_ATTR_RO(curr1_input, ina2xx_value, INA2XX_CURRENT);
/* calculated power */
static SENSOR_DEVICE_ATTR_RO(power1_input, ina2xx_value, INA2XX_POWER);
+/* over-limit power alert setting and alarm */
+static SENSOR_DEVICE_ATTR_RW(power1_crit, ina226_alert,
+ INA226_POWER_OVER_LIMIT_BIT);
+static SENSOR_DEVICE_ATTR_RO(power1_crit_alarm, ina226_alarm,
+ INA226_POWER_OVER_LIMIT_BIT);
/* shunt resistance */
static SENSOR_DEVICE_ATTR_RW(shunt_resistor, ina2xx_shunt, INA2XX_CALIBRATION);
@@ -423,6 +596,16 @@ static const struct attribute_group ina2xx_group = {
};
static struct attribute *ina226_attrs[] = {
+ &sensor_dev_attr_in0_crit.dev_attr.attr,
+ &sensor_dev_attr_in0_lcrit.dev_attr.attr,
+ &sensor_dev_attr_in0_crit_alarm.dev_attr.attr,
+ &sensor_dev_attr_in0_lcrit_alarm.dev_attr.attr,
+ &sensor_dev_attr_in1_crit.dev_attr.attr,
+ &sensor_dev_attr_in1_lcrit.dev_attr.attr,
+ &sensor_dev_attr_in1_crit_alarm.dev_attr.attr,
+ &sensor_dev_attr_in1_lcrit_alarm.dev_attr.attr,
+ &sensor_dev_attr_power1_crit.dev_attr.attr,
+ &sensor_dev_attr_power1_crit_alarm.dev_attr.attr,
&sensor_dev_attr_update_interval.dev_attr.attr,
NULL,
};