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Diffstat (limited to 'kernel/Documentation/hwmon/adc128d818')
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diff --git a/kernel/Documentation/hwmon/adc128d818 b/kernel/Documentation/hwmon/adc128d818 new file mode 100644 index 000000000..39c95004d --- /dev/null +++ b/kernel/Documentation/hwmon/adc128d818 @@ -0,0 +1,47 @@ +Kernel driver adc128d818 +======================== + +Supported chips: + * Texas Instruments ADC818D818 + Prefix: 'adc818d818' + Addresses scanned: I2C 0x1d, 0x1e, 0x1f, 0x2d, 0x2e, 0x2f + Datasheet: Publicly available at the TI website + http://www.ti.com/ + +Author: Guenter Roeck + +Description +----------- + +This driver implements support for the Texas Instruments ADC128D818. +It is described as 'ADC System Monitor with Temperature Sensor'. + +The ADC128D818 implements one temperature sensor and seven voltage sensors. + +Temperatures are measured in degrees Celsius. There is one set of limits. +When the HOT Temperature Limit is crossed, this will cause an alarm that will +be reasserted until the temperature drops below the HOT Hysteresis. +Measurements are guaranteed between -55 and +125 degrees. The temperature +measurement has a resolution of 0.5 degrees; the limits have a resolution +of 1 degree. + +Voltage sensors (also known as IN sensors) report their values in volts. +An alarm is triggered if the voltage has crossed a programmable minimum +or maximum limit. Note that minimum in this case always means 'closest to +zero'; this is important for negative voltage measurements. All voltage +inputs can measure voltages between 0 and 2.55 volts, with a resolution +of 0.625 mV. + +If an alarm triggers, it will remain triggered until the hardware register +is read at least once. This means that the cause for the alarm may +already have disappeared by the time the alarm is read. The driver +caches the alarm status for each sensor until it is at least reported +once, to ensure that alarms are reported to user space. + +The ADC128D818 only updates its values approximately once per second; +reading it more often will do no harm, but will return 'old' values. + +In addition to the scanned address list, the chip can also be configured for +addresses 0x35 to 0x37. Those addresses are not scanned. You have to instantiate +the driver explicitly if the chip is configured for any of those addresses in +your system. |