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Diffstat (limited to 'Documentation/hwmon/lm73')
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diff --git a/Documentation/hwmon/lm73 b/Documentation/hwmon/lm73 deleted file mode 100644 index 8af059dcb642..000000000000 --- a/Documentation/hwmon/lm73 +++ /dev/null @@ -1,90 +0,0 @@ -Kernel driver lm73 -================== - -Supported chips: - * Texas Instruments LM73 - Prefix: 'lm73' - Addresses scanned: I2C 0x48, 0x49, 0x4a, 0x4c, 0x4d, and 0x4e - Datasheet: Publicly available at the Texas Instruments website - http://www.ti.com/product/lm73 - -Author: Guillaume Ligneul <guillaume.ligneul@gmail.com> -Documentation: Chris Verges <kg4ysn@gmail.com> - - -Description ------------ - -The LM73 is a digital temperature sensor. All temperature values are -given in degrees Celsius. - -Measurement Resolution Support ------------------------------- - -The LM73 supports four resolutions, defined in terms of degrees C per -LSB: 0.25, 0.125, 0.0625, and 0.3125. Changing the resolution mode -affects the conversion time of the LM73's analog-to-digital converter. -From userspace, the desired resolution can be specified as a function of -conversion time via the 'update_interval' sysfs attribute for the -device. This attribute will normalize ranges of input values to the -maximum times defined for the resolution in the datasheet. - - Resolution Conv. Time Input Range - (C/LSB) (msec) (msec) - -------------------------------------- - 0.25 14 0..14 - 0.125 28 15..28 - 0.0625 56 29..56 - 0.03125 112 57..infinity - -------------------------------------- - -The following examples show how the 'update_interval' attribute can be -used to change the conversion time: - - $ echo 0 > update_interval - $ cat update_interval - 14 - $ cat temp1_input - 24250 - - $ echo 22 > update_interval - $ cat update_interval - 28 - $ cat temp1_input - 24125 - - $ echo 56 > update_interval - $ cat update_interval - 56 - $ cat temp1_input - 24062 - - $ echo 85 > update_interval - $ cat update_interval - 112 - $ cat temp1_input - 24031 - -As shown here, the lm73 driver automatically adjusts any user input for -'update_interval' via a step function. Reading back the -'update_interval' value after a write operation will confirm the -conversion time actively in use. - -Mathematically, the resolution can be derived from the conversion time -via the following function: - - g(x) = 0.250 * [log(x/14) / log(2)] - -where 'x' is the output from 'update_interval' and 'g(x)' is the -resolution in degrees C per LSB. - -Alarm Support -------------- - -The LM73 features a simple over-temperature alarm mechanism. This -feature is exposed via the sysfs attributes. - -The attributes 'temp1_max_alarm' and 'temp1_min_alarm' are flags -provided by the LM73 that indicate whether the measured temperature has -passed the 'temp1_max' and 'temp1_min' thresholds, respectively. These -values _must_ be read to clear the registers on the LM73. |