Search notes:

/sys/class

/sys/class contains representations of every device class that is registered with the kernel.

Subdirectories

Subdirectories I've found under /sys/class include

`backlight`
`bdi`
`block`
`bluetooth`
`bsg`
`cuse`
`devcoredump`
`devfreq`
`devlink`
`dma`
`dmi`
`drm`
`drm_dp_aux_dev`
`firmware`
`firmware-attributes`
`gpio`
`graphics`
`hidraw`
`hwmon`
`i2c-adapter`
`ieee80211`
`input`
`intel_scu_ipc`
`iommu`
`ipvtap`
`leds`
`lirc`
`macvtap`
`mei`
`mem`
`misc`
`mmc_host`
`nd`
`net`
`nvme`
`nvme-generic`
`nvme-subsystem`
`pci_bus`
`phy`
`powercap`
`power_supply`
`ppdev`
`ppp`
`pps`
`printer`
`ptp`
`ptp`
`pwm`
`rc`
`regulator`
`retimer`
`rfkill`
`rtc`
`scsi_device`
`scsi_disk`
`scsi_generic`
`scsi_host`
`sound`
`spidev`
`spi_master`
`thermal`
`tpm`
`tpmrm`
`tty`
`typec`
`typec_mux`
`uio`
`usb_power_delivery`
`usb_role`
`vc`
`vfio`
`video4linux`
`virtio-ports`
`vtconsole`
`wakeup`
`watchdog`
`wmi_bus`

See also

The parent directory /sys