diff options
| -rw-r--r-- | Documentation/hwmon/ds1621 | 27 | ||||
| -rw-r--r-- | drivers/hwmon/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/hwmon/ds1621.c | 27 |
3 files changed, 45 insertions, 10 deletions
diff --git a/Documentation/hwmon/ds1621 b/Documentation/hwmon/ds1621 index b61e77c..1ebaa24 100644 --- a/Documentation/hwmon/ds1621 +++ b/Documentation/hwmon/ds1621 @@ -14,6 +14,11 @@ Supported chips: Addresses scanned: I2C 0x48 - 0x4f Datasheet: Publicly available from www.datasheetarchive.com + * Maxim Integrated DS1631 + Prefix: 'ds1631' + Addresses scanned: I2C 0x48 - 0x4f + Datasheet: Publicly available from www.maximintegrated.com + * Maxim Integrated DS1721 Prefix: 'ds1721' Addresses scanned: I2C 0x48 - 0x4f @@ -69,7 +74,15 @@ Temperature conversion of the DS1621 takes up to 1000ms; internal access to non-volatile registers may last for 10ms or below. The DS1625 is pin compatible and functionally equivalent with the DS1621, -but the DS1621 is meant to replace it. +but the DS1621 is meant to replace it. The DS1631 and DS1721 are also +pin compatible with the DS1621, but provide multi-resolution support. + +Since there is no version register, there is no unique identification +for these devices. In addition, the DS1631 and DS1721 will emulate a +DS1621 device, if not explicitly instantiated (why? because the detect +function compares the temperature register values bits and checks for a +9-bit resolution). Therefore, for correct device identification and +functionality, explicit device instantiation is required. The DS1721 is pin compatible with the DS1621, has an accuracy of +/- 1.0 degree Celsius over a -10 to +85 degree range, a minimum/maximum alarm @@ -78,9 +91,17 @@ time of 750ms. In addition, the DS1721 supports four resolution settings from 9 to 12 bits (defined in degrees C per LSB: 0.5, 0.25, 0.125, and 0.0625, respectifully), -that are set at device power on to the highest resolution: 12-bits (0.0625 degree C). +that are set at device power on to the highest resolution: 12-bits. + +One additional note about the ds1721 is that although the data sheet says +the temperature flags (THF and TLF) are used internally, these flags do +get set and cleared as the actual temperature crosses the min or max settings. + +The DS1631 is also pin compatible with the DS1621 and feature compatible with +the DS1721, however the DS1631 accuracy is +/- 0.5 degree Celsius over the +same range. -Changing the DS1721 resolution mode affects the conversion time and can be +Changing the DS1631/1721 resolution mode affects the conversion time and can be done from userspace, via the device 'update_interval' sysfs attribute. This attribute will normalize range of input values to the device maximum resolution values defined in the datasheet as such: diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 0114ed4..4f71370 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -355,6 +355,7 @@ config SENSORS_DS1621 Integrated DS1621 sensor chips and compatible models including: - Dallas Semiconductor DS1625 + - Maxim Integrated DS1631 - Maxim Integrated DS1721 This driver can also be built as a module. If so, the module diff --git a/drivers/hwmon/ds1621.c b/drivers/hwmon/ds1621.c index b5d80fb..98adf77 100644 --- a/drivers/hwmon/ds1621.c +++ b/drivers/hwmon/ds1621.c @@ -10,8 +10,8 @@ * resolution, a thermal alarm output (Tout), and user-defined minimum * and maximum temperature thresholds (TH and TL). * - * The DS1625 and DS1721 are pin compatible with the DS1621 and similar - * in operation, with slight variations as noted in the device + * The DS1625, DS1631, and DS1721 are pin compatible with the DS1621 and + * similar in operation, with slight variations as noted in the device * datasheets (please refer to www.maximintegrated.com for specific * device information). * @@ -51,7 +51,7 @@ static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; /* Supported devices */ -enum chips { ds1621, ds1625, ds1721 }; +enum chips { ds1621, ds1625, ds1631, ds1721 }; /* Insmod parameters */ static int polarity = -1; @@ -69,6 +69,10 @@ MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low") * 7 6 5 4 3 2 1 0 * |Done|THF |TLF |NVB | 1 | 0 |POL |1SHOT| * + * - DS1631: + * 7 6 5 4 3 2 1 0 + * |Done|THF |TLF |NVB | R1 | R0 |POL |1SHOT| + * * - DS1721: * 7 6 5 4 3 2 1 0 * |Done| X | X | U | R1 | R0 |POL |1SHOT| @@ -139,8 +143,8 @@ static inline int DS1621_TEMP_FROM_REG(u16 reg) /* * TEMP: 0.001C/bit (-55C to +125C) * REG: - * - 1621, 1625: x = 0.5C - * - 1721: x = 0.0625C + * - 1621, 1625: 0.5C/bit + * - 1631, 1721: 0.0625C/bit * Assume highest resolution and let the bits fall where they may.. */ static inline u16 DS1621_TEMP_TO_REG(long temp) @@ -174,6 +178,7 @@ static void ds1621_init_client(struct i2c_client *client) data->update_interval = DS1625_CONVERSION_MAX; sreg = DS1621_COM_START; break; + case ds1631: case ds1721: resol = (new_conf & DS1621_REG_CONFIG_RESOL) >> DS1621_REG_CONFIG_RESOL_SHIFT; @@ -342,7 +347,7 @@ static umode_t ds1621_attribute_visible(struct kobject *kobj, struct ds1621_data *data = i2c_get_clientdata(client); if (attr == &dev_attr_update_interval.attr) - if (data->kind != ds1721) + if (data->kind == ds1621 || data->kind == ds1625) /* shhh, we're hiding update_interval */ return 0; return attr->mode; @@ -376,7 +381,14 @@ static int ds1621_detect(struct i2c_client *client, conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); if (conf < 0 || conf & DS1621_REG_CONFIG_NVB) return -ENODEV; - /* The 7 lowest bits of a temperature should always be 0. */ + /* + * The ds1621 & ds1625 use 9-bit resolution, so the 7 lowest bits + * of the temperature should always be 0 (NOTE: The other chips + * have multi-resolution support, so if they have 9-bit resolution + * configured and the min/max temperature values set accordingly, + * then if not explicitly instantiated, they *will* appear as and + * emulate a ds1621 device). + */ for (i = 0; i < ARRAY_SIZE(DS1621_REG_TEMP); i++) { temp = i2c_smbus_read_word_data(client, DS1621_REG_TEMP[i]); if (temp < 0 || (temp & 0x7f00)) @@ -438,6 +450,7 @@ static int ds1621_remove(struct i2c_client *client) static const struct i2c_device_id ds1621_id[] = { { "ds1621", ds1621 }, { "ds1625", ds1625 }, + { "ds1631", ds1631 }, { "ds1721", ds1721 }, { } }; |
