| 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. |
