VIM4 Ubuntu 22.04.1 LTS Linux 5.4.125
Linux newb here, so apologies in advance.
I’m trying to edit the fan speeds associated with each trigger temperature. These are currently defined in
#define MCU_FAN_SPEED_LOW_V2 0x32 #define MCU_FAN_SPEED_MID_V2 0x48 #define MCU_FAN_SPEED_HIGH_V2 0x64
It seems it would be ideal to expose the fan speeds in an analogous way to how trigger temperatures were exposed as writable files within
/sys/class/fan (see GitHub issue), e.g. with files like
speed_high. This would allow a user to define a basic fan curve. However, from what I gather, I’d need to edit
khadas-mcu.c and rebuild the kernel (please correct me if I’m wrong), which is currently out of my depth.
I have been able to get the MCU to change the fan speed directly over i2c, e.g. with the following:
$bash fan.sh off i2cset -f -y 6 0x18 0x8a 0x16 # 0x16 = 22% duty
In sum, I’d be generally interested in hearing ideas as to how to implement a basic fan curve. If exposing the speeds as writable files in
/sys/class/fan does seem to be a reasonable approach, I’d be interested in learning how to accomplish this (and/or to see this added as a feature).