diff options
| author | Mike Looijmans <mike.looijmans@topic.nl> | 2016-01-15 10:54:59 +0100 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2016-03-05 06:25:34 -0800 |
| commit | df922703574ebe9035045f7c7242a0ec0e11b980 (patch) | |
| tree | 1c9ffb5cdc48f11f61140c7db2555f2dffacb774 /Documentation/hwmon/ltc2990 | |
| parent | c32f5eff2db51f0126b0a4e42bdefea2d9d2872e (diff) | |
hwmon: Add LTC2990 sensor driver
This adds support for the Linear Technology LTC2990 I2C System Monitor.
The LTC2990 supports a combination of voltage, current and temperature
monitoring. This driver currently only supports reading two currents
by measuring two differential voltages across series resistors, in
addition to the Vcc supply voltage and internal temperature.
This is sufficient to support the Topic Miami SOM which uses this chip
to monitor the currents flowing into the FPGA and the CPU parts.
Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'Documentation/hwmon/ltc2990')
| -rw-r--r-- | Documentation/hwmon/ltc2990 | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/Documentation/hwmon/ltc2990 b/Documentation/hwmon/ltc2990 new file mode 100644 index 000000000000..c25211e90bdc --- /dev/null +++ b/Documentation/hwmon/ltc2990 @@ -0,0 +1,43 @@ +Kernel driver ltc2990 +===================== + +Supported chips: + * Linear Technology LTC2990 + Prefix: 'ltc2990' + Addresses scanned: - + Datasheet: http://www.linear.com/product/ltc2990 + +Author: Mike Looijmans <mike.looijmans@topic.nl> + + +Description +----------- + +LTC2990 is a Quad I2C Voltage, Current and Temperature Monitor. +The chip's inputs can measure 4 voltages, or two inputs together (1+2 and 3+4) +can be combined to measure a differential voltage, which is typically used to +measure current through a series resistor, or a temperature. + +This driver currently uses the 2x differential mode only. In order to support +other modes, the driver will need to be expanded. + + +Usage Notes +----------- + +This driver does not probe for PMBus devices. You will have to instantiate +devices explicitly. + + +Sysfs attributes +---------------- + +The "curr*_input" measurements actually report the voltage drop across the +input pins in microvolts. This is equivalent to the current through a 1mOhm +sense resistor. Divide the reported value by the actual sense resistor value +in mOhm to get the actual value. + +in0_input Voltage at Vcc pin in millivolt (range 2.5V to 5V) +temp1_input Internal chip temperature in millidegrees Celcius +curr1_input Current in mA across v1-v2 assuming a 1mOhm sense resistor. +curr2_input Current in mA across v3-v4 assuming a 1mOhm sense resistor. |