Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) Kernel driver adt7462
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) =====================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) Supported chips:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)   * Analog Devices ADT7462
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)     Prefix: 'adt7462'
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)     Addresses scanned: I2C 0x58, 0x5C
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)     Datasheet: Publicly available at the Analog Devices website
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) Author: Darrick J. Wong
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) Description
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) -----------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) This driver implements support for the Analog Devices ADT7462 chip family.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) This chip is a bit of a beast.  It has 8 counters for measuring fan speed.  It
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) can also measure 13 voltages or 4 temperatures, or various combinations of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) two.  See the chip documentation for more details about the exact set of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) configurations.  This driver does not allow one to configure the chip; that is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) left to the system designer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) A sophisticated control system for the PWM outputs is designed into the ADT7462
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) that allows fan speed to be adjusted automatically based on any of the three
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) temperature sensors. Each PWM output is individually adjustable and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) programmable. Once configured, the ADT7462 will adjust the PWM outputs in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) response to the measured temperatures without further host intervention.  This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) feature can also be disabled for manual control of the PWM's.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) Each of the measured inputs (voltage, temperature, fan speed) has
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) corresponding high/low limit values. The ADT7462 will signal an ALARM if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) any measured value exceeds either limit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) The ADT7462 samples all inputs continuously. The driver will not read
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) the registers more often than once every other second. Further,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) configuration data is only read once per minute.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) Special Features
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) ----------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) The ADT7462 have a 10-bit ADC and can therefore measure temperatures
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) with 0.25 degC resolution.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) The Analog Devices datasheet is very detailed and describes a procedure for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) determining an optimal configuration for the automatic PWM control.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) The driver will report sensor labels when it is able to determine that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) information from the configuration registers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) Configuration Notes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) -------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) Besides standard interfaces driver adds the following:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * PWM Control
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) * pwm#_auto_point1_pwm and temp#_auto_point1_temp and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) * pwm#_auto_point2_pwm and temp#_auto_point2_temp -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)   - point1: Set the pwm speed at a lower temperature bound.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65)   - point2: Set the pwm speed at a higher temperature bound.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) The ADT7462 will scale the pwm between the lower and higher pwm speed when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) the temperature is between the two temperature boundaries.  PWM values range
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) from 0 (off) to 255 (full speed).  Fan speed will be set to maximum when the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) temperature sensor associated with the PWM control exceeds temp#_max.