diff options
| author | Robert Coulson <rob.coulson@gmail.com> | 2013-05-16 15:10:41 -0700 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2013-06-27 10:29:02 -0700 |
| commit | 79c1cc1c90c0ccaddd20965ea19205c54addd5f7 (patch) | |
| tree | 0a1de32d3c503e2eaf56130a315b9753530f3b68 /Documentation/hwmon/ds1621 | |
| parent | 3a8fe3315571e896489d2e271ffe7f935bfc5ce8 (diff) | |
| download | linux-79c1cc1c90c0ccaddd20965ea19205c54addd5f7.tar.bz2 | |
hwmon: (ds1621) Add ds1631 chip support to ds1621 driver and documentation
Add definitions, information, and code for ds1631 chip support
to the ds1621 driver.
Signed-off-by: Robert Coulson <rob.coulson@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'Documentation/hwmon/ds1621')
| -rw-r--r-- | Documentation/hwmon/ds1621 | 27 |
1 files changed, 24 insertions, 3 deletions
diff --git a/Documentation/hwmon/ds1621 b/Documentation/hwmon/ds1621 index b61e77c6b1cb..1ebaa2485770 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: |