1Kernel driver adc128d818 2======================== 3 4Supported chips: 5 6 * Texas Instruments ADC818D818 7 8 Prefix: 'adc818d818' 9 10 Addresses scanned: I2C 0x1d, 0x1e, 0x1f, 0x2d, 0x2e, 0x2f 11 12 Datasheet: Publicly available at the TI website https://www.ti.com/ 13 14Author: Guenter Roeck 15 16Description 17----------- 18 19This driver implements support for the Texas Instruments ADC128D818. 20It is described as 'ADC System Monitor with Temperature Sensor'. 21 22The ADC128D818 implements one temperature sensor and seven voltage sensors. 23 24Temperatures are measured in degrees Celsius. There is one set of limits. 25When the HOT Temperature Limit is crossed, this will cause an alarm that will 26be reasserted until the temperature drops below the HOT Hysteresis. 27Measurements are guaranteed between -55 and +125 degrees. The temperature 28measurement has a resolution of 0.5 degrees; the limits have a resolution 29of 1 degree. 30 31Voltage sensors (also known as IN sensors) report their values in volts. 32An alarm is triggered if the voltage has crossed a programmable minimum 33or maximum limit. Note that minimum in this case always means 'closest to 34zero'; this is important for negative voltage measurements. All voltage 35inputs can measure voltages between 0 and 2.55 volts, with a resolution 36of 0.625 mV. 37 38If an alarm triggers, it will remain triggered until the hardware register 39is read at least once. This means that the cause for the alarm may 40already have disappeared by the time the alarm is read. The driver 41caches the alarm status for each sensor until it is at least reported 42once, to ensure that alarms are reported to user space. 43 44The ADC128D818 only updates its values approximately once per second; 45reading it more often will do no harm, but will return 'old' values. 46 47In addition to the scanned address list, the chip can also be configured for 48addresses 0x35 to 0x37. Those addresses are not scanned. You have to instantiate 49the driver explicitly if the chip is configured for any of those addresses in 50your system. 51