mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-23 20:53:53 +08:00
b4c9c1a798
ADC128D818 is a System Monitor with Temperature Sensor. It is similar to LM80 and LM96080, but has 16 bit wide sensor registers and no fan speed monitoring. Signed-off-by: Guenter Roeck <linux@roeck-us.net>
48 lines
2.0 KiB
Plaintext
48 lines
2.0 KiB
Plaintext
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.
|