diff options
| -rw-r--r-- | drivers/hwmon/nct7802.c | 71 |
1 files changed, 67 insertions, 4 deletions
diff --git a/drivers/hwmon/nct7802.c b/drivers/hwmon/nct7802.c index 7915c2f2c85d..2e97e56c72c7 100644 --- a/drivers/hwmon/nct7802.c +++ b/drivers/hwmon/nct7802.c @@ -58,6 +58,8 @@ static const u8 REG_VOLTAGE_LIMIT_MSB_SHIFT[2][5] = { struct nct7802_data { struct regmap *regmap; struct mutex access_lock; /* for multi-byte read and write operations */ + u8 in_status; + struct mutex in_alarm_lock; }; static ssize_t temp_type_show(struct device *dev, @@ -368,6 +370,66 @@ static ssize_t in_store(struct device *dev, struct device_attribute *attr, return err ? : count; } +static ssize_t in_alarm_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr); + struct nct7802_data *data = dev_get_drvdata(dev); + int volt, min, max, ret; + unsigned int val; + + mutex_lock(&data->in_alarm_lock); + + /* + * The SMI Voltage status register is the only register giving a status + * for voltages. A bit is set for each input crossing a threshold, in + * both direction, but the "inside" or "outside" limits info is not + * available. Also this register is cleared on read. + * Note: this is not explicitly spelled out in the datasheet, but + * from experiment. + * To deal with this we use a status cache with one validity bit and + * one status bit for each input. Validity is cleared at startup and + * each time the register reports a change, and the status is processed + * by software based on current input value and limits. + */ + ret = regmap_read(data->regmap, 0x1e, &val); /* SMI Voltage status */ + if (ret < 0) + goto abort; + + /* invalidate cached status for all inputs crossing a threshold */ + data->in_status &= ~((val & 0x0f) << 4); + + /* if cached status for requested input is invalid, update it */ + if (!(data->in_status & (0x10 << sattr->index))) { + ret = nct7802_read_voltage(data, sattr->nr, 0); + if (ret < 0) + goto abort; + volt = ret; + + ret = nct7802_read_voltage(data, sattr->nr, 1); + if (ret < 0) + goto abort; + min = ret; + + ret = nct7802_read_voltage(data, sattr->nr, 2); + if (ret < 0) + goto abort; + max = ret; + + if (volt < min || volt > max) + data->in_status |= (1 << sattr->index); + else + data->in_status &= ~(1 << sattr->index); + + data->in_status |= 0x10 << sattr->index; + } + + ret = sprintf(buf, "%u\n", !!(data->in_status & (1 << sattr->index))); +abort: + mutex_unlock(&data->in_alarm_lock); + return ret; +} + static ssize_t temp_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -660,7 +722,7 @@ static const struct attribute_group nct7802_temp_group = { static SENSOR_DEVICE_ATTR_2_RO(in0_input, in, 0, 0); static SENSOR_DEVICE_ATTR_2_RW(in0_min, in, 0, 1); static SENSOR_DEVICE_ATTR_2_RW(in0_max, in, 0, 2); -static SENSOR_DEVICE_ATTR_2_RO(in0_alarm, alarm, 0x1e, 3); +static SENSOR_DEVICE_ATTR_2_RO(in0_alarm, in_alarm, 0, 3); static SENSOR_DEVICE_ATTR_2_RW(in0_beep, beep, 0x5a, 3); static SENSOR_DEVICE_ATTR_2_RO(in1_input, in, 1, 0); @@ -668,19 +730,19 @@ static SENSOR_DEVICE_ATTR_2_RO(in1_input, in, 1, 0); static SENSOR_DEVICE_ATTR_2_RO(in2_input, in, 2, 0); static SENSOR_DEVICE_ATTR_2_RW(in2_min, in, 2, 1); static SENSOR_DEVICE_ATTR_2_RW(in2_max, in, 2, 2); -static SENSOR_DEVICE_ATTR_2_RO(in2_alarm, alarm, 0x1e, 0); +static SENSOR_DEVICE_ATTR_2_RO(in2_alarm, in_alarm, 2, 0); static SENSOR_DEVICE_ATTR_2_RW(in2_beep, beep, 0x5a, 0); static SENSOR_DEVICE_ATTR_2_RO(in3_input, in, 3, 0); static SENSOR_DEVICE_ATTR_2_RW(in3_min, in, 3, 1); static SENSOR_DEVICE_ATTR_2_RW(in3_max, in, 3, 2); -static SENSOR_DEVICE_ATTR_2_RO(in3_alarm, alarm, 0x1e, 1); +static SENSOR_DEVICE_ATTR_2_RO(in3_alarm, in_alarm, 3, 1); static SENSOR_DEVICE_ATTR_2_RW(in3_beep, beep, 0x5a, 1); static SENSOR_DEVICE_ATTR_2_RO(in4_input, in, 4, 0); static SENSOR_DEVICE_ATTR_2_RW(in4_min, in, 4, 1); static SENSOR_DEVICE_ATTR_2_RW(in4_max, in, 4, 2); -static SENSOR_DEVICE_ATTR_2_RO(in4_alarm, alarm, 0x1e, 2); +static SENSOR_DEVICE_ATTR_2_RO(in4_alarm, in_alarm, 4, 2); static SENSOR_DEVICE_ATTR_2_RW(in4_beep, beep, 0x5a, 2); static struct attribute *nct7802_in_attrs[] = { @@ -1011,6 +1073,7 @@ static int nct7802_probe(struct i2c_client *client, return PTR_ERR(data->regmap); mutex_init(&data->access_lock); + mutex_init(&data->in_alarm_lock); ret = nct7802_init_chip(data); if (ret < 0) |