diff options
Diffstat (limited to 'Documentation/hwmon/ltc4245')
| -rw-r--r-- | Documentation/hwmon/ltc4245 | 33 |
1 files changed, 27 insertions, 6 deletions
diff --git a/Documentation/hwmon/ltc4245 b/Documentation/hwmon/ltc4245 index bae7a3adc5d..b478b086496 100644 --- a/Documentation/hwmon/ltc4245 +++ b/Documentation/hwmon/ltc4245 @@ -23,12 +23,13 @@ Usage Notes ----------- This driver does not probe for LTC4245 devices, due to the fact that some -of the possible addresses are unfriendly to probing. You will need to use -the "force" parameter to tell the driver where to find the device. +of the possible addresses are unfriendly to probing. You will have to +instantiate the devices explicitly. Example: the following will load the driver for an LTC4245 at address 0x23 on I2C bus #1: -$ modprobe ltc4245 force=1,0x23 +$ modprobe ltc4245 +$ echo ltc4245 0x23 > /sys/bus/i2c/devices/i2c-1/new_device Sysfs entries @@ -71,11 +72,31 @@ in6_min_alarm 5v output undervoltage alarm in7_min_alarm 3v output undervoltage alarm in8_min_alarm Vee (-12v) output undervoltage alarm -in9_input GPIO #1 voltage data -in10_input GPIO #2 voltage data -in11_input GPIO #3 voltage data +in9_input GPIO voltage data (see note 1) +in10_input GPIO voltage data (see note 1) +in11_input GPIO voltage data (see note 1) power1_input 12v power usage (mW) power2_input 5v power usage (mW) power3_input 3v power usage (mW) power4_input Vee (-12v) power usage (mW) + + +Note 1 +------ + +If you have NOT configured the driver to sample all GPIO pins as analog +voltages, then the in10_input and in11_input sysfs attributes will not be +created. The driver will sample the GPIO pin that is currently connected to the +ADC as an analog voltage, and report the value in in9_input. + +If you have configured the driver to sample all GPIO pins as analog voltages, +then they will be sampled in round-robin fashion. If userspace reads too +slowly, -EAGAIN will be returned when you read the sysfs attribute containing +the sensor reading. + +The LTC4245 chip can be configured to sample all GPIO pins with two methods: +1) platform data -- see include/linux/i2c/ltc4245.h +2) OF device tree -- add the "ltc4245,use-extra-gpios" property to each chip + +The default mode of operation is to sample a single GPIO pin. |