diff options
Diffstat (limited to 'Documentation/hwmon')
| -rw-r--r-- | Documentation/hwmon/adt7462 | 67 | ||||
| -rw-r--r-- | Documentation/hwmon/lis3lv02d | 49 |
2 files changed, 116 insertions, 0 deletions
diff --git a/Documentation/hwmon/adt7462 b/Documentation/hwmon/adt7462 new file mode 100644 index 000000000000..ec660b328275 --- /dev/null +++ b/Documentation/hwmon/adt7462 @@ -0,0 +1,67 @@ +Kernel driver adt7462 +====================== + +Supported chips: + * Analog Devices ADT7462 + Prefix: 'adt7462' + Addresses scanned: I2C 0x58, 0x5C + Datasheet: Publicly available at the Analog Devices website + +Author: Darrick J. Wong + +Description +----------- + +This driver implements support for the Analog Devices ADT7462 chip family. + +This chip is a bit of a beast. It has 8 counters for measuring fan speed. It +can also measure 13 voltages or 4 temperatures, or various combinations of the +two. See the chip documentation for more details about the exact set of +configurations. This driver does not allow one to configure the chip; that is +left to the system designer. + +A sophisticated control system for the PWM outputs is designed into the ADT7462 +that allows fan speed to be adjusted automatically based on any of the three +temperature sensors. Each PWM output is individually adjustable and +programmable. Once configured, the ADT7462 will adjust the PWM outputs in +response to the measured temperatures without further host intervention. This +feature can also be disabled for manual control of the PWM's. + +Each of the measured inputs (voltage, temperature, fan speed) has +corresponding high/low limit values. The ADT7462 will signal an ALARM if +any measured value exceeds either limit. + +The ADT7462 samples all inputs continuously. The driver will not read +the registers more often than once every other second. Further, +configuration data is only read once per minute. + +Special Features +---------------- + +The ADT7462 have a 10-bit ADC and can therefore measure temperatures +with 0.25 degC resolution. + +The Analog Devices datasheet is very detailed and describes a procedure for +determining an optimal configuration for the automatic PWM control. + +The driver will report sensor labels when it is able to determine that +information from the configuration registers. + +Configuration Notes +------------------- + +Besides standard interfaces driver adds the following: + +* PWM Control + +* pwm#_auto_point1_pwm and temp#_auto_point1_temp and +* pwm#_auto_point2_pwm and temp#_auto_point2_temp - + +point1: Set the pwm speed at a lower temperature bound. +point2: Set the pwm speed at a higher temperature bound. + +The ADT7462 will scale the pwm between the lower and higher pwm speed when +the temperature is between the two temperature boundaries. PWM values range +from 0 (off) to 255 (full speed). Fan speed will be set to maximum when the +temperature sensor associated with the PWM control exceeds temp#_max. + diff --git a/Documentation/hwmon/lis3lv02d b/Documentation/hwmon/lis3lv02d new file mode 100644 index 000000000000..65dfb0c0fd67 --- /dev/null +++ b/Documentation/hwmon/lis3lv02d @@ -0,0 +1,49 @@ +Kernel driver lis3lv02d +================== + +Supported chips: + + * STMicroelectronics LIS3LV02DL and LIS3LV02DQ + +Author: + Yan Burman <burman.yan@gmail.com> + Eric Piel <eric.piel@tremplin-utc.net> + + +Description +----------- + +This driver provides support for the accelerometer found in various HP laptops +sporting the feature officially called "HP Mobile Data Protection System 3D" or +"HP 3D DriveGuard". It detect automatically laptops with this sensor. Known models +(for now the HP 2133, nc6420, nc2510, nc8510, nc84x0, nw9440 and nx9420) will +have their axis automatically oriented on standard way (eg: you can directly +play neverball). The accelerometer data is readable via +/sys/devices/platform/lis3lv02d. + +Sysfs attributes under /sys/devices/platform/lis3lv02d/: +position - 3D position that the accelerometer reports. Format: "(x,y,z)" +calibrate - read: values (x, y, z) that are used as the base for input class device operation. + write: forces the base to be recalibrated with the current position. +rate - reports the sampling rate of the accelerometer device in HZ + +This driver also provides an absolute input class device, allowing +the laptop to act as a pinball machine-esque joystick. + +Axes orientation +---------------- + +For better compatibility between the various laptops. The values reported by +the accelerometer are converted into a "standard" organisation of the axes +(aka "can play neverball out of the box"): + * When the laptop is horizontal the position reported is about 0 for X and Y +and a positive value for Z + * If the left side is elevated, X increases (becomes positive) + * If the front side (where the touchpad is) is elevated, Y decreases (becomes negative) + * If the laptop is put upside-down, Z becomes negative + +If your laptop model is not recognized (cf "dmesg"), you can send an email to the +authors to add it to the database. When reporting a new laptop, please include +the output of "dmidecode" plus the value of /sys/devices/platform/lis3lv02d/position +in these four cases. + |