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author | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-04-17 06:46:29 -0300 |
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committer | Guenter Roeck <linux@roeck-us.net> | 2019-04-17 10:37:23 -0700 |
commit | 7ebd8b66dd9e5a0b65e5ee5e2b8e7ca382ec97b7 (patch) | |
tree | 9db30159bd32bec125c7d49e80a79bb7c4da0c8e /Documentation/hwmon/ltc4261.rst | |
parent | b04f2f7d387b3160883c2a1f5e2285483a791e82 (diff) | |
download | linux-next-7ebd8b66dd9e5a0b65e5ee5e2b8e7ca382ec97b7.tar.gz |
docs: hwmon: Add an index file and rename docs to *.rst
Now that all files were converted to ReST format, rename them
and add an index.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'Documentation/hwmon/ltc4261.rst')
-rw-r--r-- | Documentation/hwmon/ltc4261.rst | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/Documentation/hwmon/ltc4261.rst b/Documentation/hwmon/ltc4261.rst new file mode 100644 index 000000000000..c80233f8082e --- /dev/null +++ b/Documentation/hwmon/ltc4261.rst @@ -0,0 +1,71 @@ +Kernel driver ltc4261 +===================== + +Supported chips: + + * Linear Technology LTC4261 + + Prefix: 'ltc4261' + + Addresses scanned: - + + Datasheet: + + http://cds.linear.com/docs/Datasheet/42612fb.pdf + +Author: Guenter Roeck <linux@roeck-us.net> + + +Description +----------- + +The LTC4261/LTC4261-2 negative voltage Hot Swap controllers allow a board +to be safely inserted and removed from a live backplane. + + +Usage Notes +----------- + +This driver does not probe for LTC4261 devices, since there is no register +which can be safely used to identify the chip. You will have to instantiate +the devices explicitly. + +Example: the following will load the driver for an LTC4261 at address 0x10 +on I2C bus #1:: + + $ modprobe ltc4261 + $ echo ltc4261 0x10 > /sys/bus/i2c/devices/i2c-1/new_device + + +Sysfs entries +------------- + +Voltage readings provided by this driver are reported as obtained from the ADC +registers. If a set of voltage divider resistors is installed, calculate the +real voltage by multiplying the reported value with (R1+R2)/R2, where R1 is the +value of the divider resistor against the measured voltage and R2 is the value +of the divider resistor against Ground. + +Current reading provided by this driver is reported as obtained from the ADC +Current Sense register. The reported value assumes that a 1 mOhm sense resistor +is installed. If a different sense resistor is installed, calculate the real +current by dividing the reported value by the sense resistor value in mOhm. + +The chip has two voltage sensors, but only one set of voltage alarm status bits. +In many many designs, those alarms are associated with the ADIN2 sensor, due to +the proximity of the ADIN2 pin to the OV pin. ADIN2 is, however, not available +on all chip variants. To ensure that the alarm condition is reported to the user, +report it with both voltage sensors. + +======================= ============================= +in1_input ADIN2 voltage (mV) +in1_min_alarm ADIN/ADIN2 Undervoltage alarm +in1_max_alarm ADIN/ADIN2 Overvoltage alarm + +in2_input ADIN voltage (mV) +in2_min_alarm ADIN/ADIN2 Undervoltage alarm +in2_max_alarm ADIN/ADIN2 Overvoltage alarm + +curr1_input SENSE current (mA) +curr1_alarm SENSE overcurrent alarm +======================= ============================= |