Hi All, I would like to enable CONFIG_REGULATOR on x86_64, to fix USB PD negotiating (and charging with more the 0.5 A in general) and battery monitoring on Intel Cherry Trail devices which use an Intel PMIC + FUSB302 Type-C controller to enable USB-PD charging. Since the USB-PD negotiation in this case is handled by the kernel rather then by firmware in the Alpine Ridge controller, the kernel also needs to enable/disable the 5V boost converter feeding 5v to the Type-C port when it is in host / power-source mode and this is modeled as a regulator. One of the drivers for the complex of 4 ICs which implement the Type-C and battery charging monitoring on these devices has a Kconfig dep on CONFIG_REGULATOR because of this and without this driver these devices are limited to charging (or rather slowly discharging) at 5V 0.5A rather then charging at up to 12V 3A, also without this battery monitoring will not work and the kernel will be unable to make the port provide 5V when a Type-C to USB-A-receptacle cable gets plugged in. Downside of this is a slightly bigger kernel (the regulator framework is tiny) and some messages like these when some drivers load: [ 19.955279] rt5645 i2c-10EC5645:00: i2c-10EC5645:00 supply avdd not found, using dummy regulator [ 19.955331] rt5645 i2c-10EC5645:00: i2c-10EC5645:00 supply cpvdd not found, using dummy regulator As these drivers now actually call into the regulator framework which prints these messages, rather then calling empty stubs. These are printed at "warning" level so will not show up on the console. So if there are no objections I will push a commit enabling CONFIG_REGULATOR on x86_64 one of the coming days. Regards, Hans _______________________________________________ kernel mailing list -- kernel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to kernel-leave@xxxxxxxxxxxxxxxxxxxxxxx
