diff options
| -rw-r--r-- | Documentation/hwmon/lm75 | 15 | ||||
| -rw-r--r-- | drivers/hwmon/Kconfig | 2 | ||||
| -rw-r--r-- | drivers/hwmon/lm75.c | 92 |
3 files changed, 94 insertions, 15 deletions
diff --git a/Documentation/hwmon/lm75 b/Documentation/hwmon/lm75 index 69af1c7db6b..2560a9c6d44 100644 --- a/Documentation/hwmon/lm75 +++ b/Documentation/hwmon/lm75 @@ -12,11 +12,11 @@ Supported chips: Addresses scanned: I2C 0x48 - 0x4f Datasheet: Publicly available at the National Semiconductor website http://www.national.com/ - * Dallas Semiconductor DS75, DS1775 - Prefixes: 'ds75', 'ds1775' + * Dallas Semiconductor (now Maxim) DS75, DS1775, DS7505 + Prefixes: 'ds75', 'ds1775', 'ds7505' Addresses scanned: none - Datasheet: Publicly available at the Dallas Semiconductor website - http://www.maxim-ic.com/ + Datasheet: Publicly available at the Maxim website + http://www.maximintegrated.com/ * Maxim MAX6625, MAX6626 Prefixes: 'max6625', 'max6626' Addresses scanned: none @@ -67,7 +67,8 @@ the temperature falls below the Hysteresis value. All temperatures are in degrees Celsius, and are guaranteed within a range of -55 to +125 degrees. -The LM75 only updates its values each 1.5 seconds; reading it more often +The driver caches the values for a period varying between 1 second for the +slowest chips and 125 ms for the fastest chips; reading it more often will do no harm, but will return 'old' values. The original LM75 was typically used in combination with LM78-like chips @@ -78,8 +79,8 @@ The LM75 is essentially an industry standard; there may be other LM75 clones not listed here, with or without various enhancements, that are supported. The clones are not detected by the driver, unless they reproduce the exact register tricks of the original LM75, and must -therefore be instantiated explicitly. The specific enhancements (such as -higher resolution) are not currently supported by the driver. +therefore be instantiated explicitly. Higher resolution up to 12-bit +is supported by this driver, other specific enhancements are not. The LM77 is not supported, contrary to what we pretended for a long time. Both chips are simply not compatible, value encoding differs. diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 9c333d47143..0428e8a74b1 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -630,7 +630,7 @@ config SENSORS_LM75 temperature sensor chip, with models including: - Analog Devices ADT75 - - Dallas Semiconductor DS75 and DS1775 + - Dallas Semiconductor DS75, DS1775 and DS7505 - Maxim MAX6625 and MAX6626 - Microchip MCP980x - National Semiconductor LM75, LM75A diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c index 291edfff55b..c03b490bba8 100644 --- a/drivers/hwmon/lm75.c +++ b/drivers/hwmon/lm75.c @@ -38,6 +38,7 @@ enum lm75_type { /* keep sorted in alphabetical order */ adt75, ds1775, ds75, + ds7505, lm75, lm75a, max6625, @@ -71,9 +72,12 @@ struct lm75_data { struct device *hwmon_dev; struct mutex update_lock; u8 orig_conf; + u8 resolution; /* In bits, between 9 and 12 */ + u8 resolution_limits; char valid; /* !=0 if registers are valid */ unsigned long last_updated; /* In jiffies */ - u16 temp[3]; /* Register values, + unsigned long sample_time; /* In jiffies */ + s16 temp[3]; /* Register values, 0 = input 1 = max 2 = hyst */ @@ -93,12 +97,15 @@ static ssize_t show_temp(struct device *dev, struct device_attribute *da, { struct sensor_device_attribute *attr = to_sensor_dev_attr(da); struct lm75_data *data = lm75_update_device(dev); + long temp; if (IS_ERR(data)) return PTR_ERR(data); - return sprintf(buf, "%d\n", - LM75_TEMP_FROM_REG(data->temp[attr->index])); + temp = ((data->temp[attr->index] >> (16 - data->resolution)) * 1000) + >> (data->resolution - 8); + + return sprintf(buf, "%ld\n", temp); } static ssize_t set_temp(struct device *dev, struct device_attribute *da, @@ -110,13 +117,25 @@ static ssize_t set_temp(struct device *dev, struct device_attribute *da, int nr = attr->index; long temp; int error; + u8 resolution; error = kstrtol(buf, 10, &temp); if (error) return error; + /* + * Resolution of limit registers is assumed to be the same as the + * temperature input register resolution unless given explicitly. + */ + if (attr->index && data->resolution_limits) + resolution = data->resolution_limits; + else + resolution = data->resolution; + mutex_lock(&data->update_lock); - data->temp[nr] = LM75_TEMP_TO_REG(temp); + temp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX); + data->temp[nr] = DIV_ROUND_CLOSEST(temp << (resolution - 8), + 1000) << (16 - resolution); lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]); mutex_unlock(&data->update_lock); return count; @@ -151,6 +170,7 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id) int status; u8 set_mask, clr_mask; int new; + enum lm75_type kind = id->driver_data; if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA)) @@ -167,8 +187,65 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id) * Then tweak to be more precise when appropriate. */ set_mask = 0; - clr_mask = (1 << 0) /* continuous conversions */ - | (1 << 6) | (1 << 5); /* 9-bit mode */ + clr_mask = LM75_SHUTDOWN; /* continuous conversions */ + + switch (kind) { + case adt75: + clr_mask |= 1 << 5; /* not one-shot mode */ + data->resolution = 12; + data->sample_time = HZ / 8; + break; + case ds1775: + case ds75: + case stds75: + clr_mask |= 3 << 5; + set_mask |= 2 << 5; /* 11-bit mode */ + data->resolution = 11; + data->sample_time = HZ; + break; + case ds7505: + set_mask |= 3 << 5; /* 12-bit mode */ + data->resolution = 12; + data->sample_time = HZ / 4; + break; + case lm75: + case lm75a: + data->resolution = 9; + data->sample_time = HZ / 2; + break; + case max6625: + data->resolution = 9; + data->sample_time = HZ / 4; + break; + case max6626: + data->resolution = 12; + data->resolution_limits = 9; + data->sample_time = HZ / 4; + break; + case tcn75: + data->resolution = 9; + data->sample_time = HZ / 8; + break; + case mcp980x: + data->resolution_limits = 9; + /* fall through */ + case tmp100: + case tmp101: + set_mask |= 3 << 5; /* 12-bit mode */ + data->resolution = 12; + data->sample_time = HZ; + clr_mask |= 1 << 7; /* not one-shot mode */ + break; + case tmp105: + case tmp175: + case tmp275: + case tmp75: + set_mask |= 3 << 5; /* 12-bit mode */ + clr_mask |= 1 << 7; /* not one-shot mode */ + data->resolution = 12; + data->sample_time = HZ / 2; + break; + } /* configure as specified */ status = lm75_read_value(client, LM75_REG_CONF); @@ -218,6 +295,7 @@ static const struct i2c_device_id lm75_ids[] = { { "adt75", adt75, }, { "ds1775", ds1775, }, { "ds75", ds75, }, + { "ds7505", ds7505, }, { "lm75", lm75, }, { "lm75a", lm75a, }, { "max6625", max6625, }, @@ -407,7 +485,7 @@ static struct lm75_data *lm75_update_device(struct device *dev) mutex_lock(&data->update_lock); - if (time_after(jiffies, data->last_updated + HZ + HZ / 2) + if (time_after(jiffies, data->last_updated + data->sample_time) || !data->valid) { int i; dev_dbg(&client->dev, "Starting lm75 update\n"); |