| 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. |