0001 Kernel driver adc128d818
0002 ========================
0003
0004 Supported chips:
0005
0006 * Texas Instruments ADC818D818
0007
0008 Prefix: 'adc818d818'
0009
0010 Addresses scanned: I2C 0x1d, 0x1e, 0x1f, 0x2d, 0x2e, 0x2f
0011
0012 Datasheet: Publicly available at the TI website https://www.ti.com/
0013
0014 Author: Guenter Roeck
0015
0016 Description
0017 -----------
0018
0019 This driver implements support for the Texas Instruments ADC128D818.
0020 It is described as 'ADC System Monitor with Temperature Sensor'.
0021
0022 The ADC128D818 implements one temperature sensor and seven voltage sensors.
0023
0024 Temperatures are measured in degrees Celsius. There is one set of limits.
0025 When the HOT Temperature Limit is crossed, this will cause an alarm that will
0026 be reasserted until the temperature drops below the HOT Hysteresis.
0027 Measurements are guaranteed between -55 and +125 degrees. The temperature
0028 measurement has a resolution of 0.5 degrees; the limits have a resolution
0029 of 1 degree.
0030
0031 Voltage sensors (also known as IN sensors) report their values in volts.
0032 An alarm is triggered if the voltage has crossed a programmable minimum
0033 or maximum limit. Note that minimum in this case always means 'closest to
0034 zero'; this is important for negative voltage measurements. All voltage
0035 inputs can measure voltages between 0 and 2.55 volts, with a resolution
0036 of 0.625 mV.
0037
0038 If an alarm triggers, it will remain triggered until the hardware register
0039 is read at least once. This means that the cause for the alarm may
0040 already have disappeared by the time the alarm is read. The driver
0041 caches the alarm status for each sensor until it is at least reported
0042 once, to ensure that alarms are reported to user space.
0043
0044 The ADC128D818 only updates its values approximately once per second;
0045 reading it more often will do no harm, but will return 'old' values.
0046
0047 In addition to the scanned address list, the chip can also be configured for
0048 addresses 0x35 to 0x37. Those addresses are not scanned. You have to instantiate
0049 the driver explicitly if the chip is configured for any of those addresses in
0050 your system.
