Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) Kernel driver g760a
^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)   * Global Mixed-mode Technology Inc. G760A
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)     Prefix: 'g760a'
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)     Datasheet: Publicly available at the GMT website
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)       http://www.gmt.com.tw/product/datasheet/EDS-760A.pdf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) Author: Herbert Valerio Riedel <hvr@gnu.org>
^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) The GMT G760A Fan Speed PWM Controller is connected directly to a fan
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) and performs closed-loop control of the fan speed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) The fan speed is programmed by setting the period via 'pwm1' of two
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) consecutive speed pulses. The period is defined in terms of clock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) cycle counts of an assumed 32kHz clock source.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) Setting a period of 0 stops the fan; setting the period to 255 sets
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) fan to maximum speed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) The measured fan rotation speed returned via 'fan1_input' is derived
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) from the measured speed pulse period by assuming again a 32kHz clock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) source and a 2 pulse-per-revolution fan.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) The 'alarms' file provides access to the two alarm bits provided by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) the G760A chip's status register: Bit 0 is set when the actual fan
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) speed differs more than 20% with respect to the programmed fan speed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) bit 1 is set when fan speed is below 1920 RPM.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) The g760a driver will not update its values more frequently than every
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) other second; reading them more often will do no harm, but will return
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 'old' values.