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-rw-r--r--drivers/hwmon/nct7802.c71
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)