johannes@xxodd-ubuntu:/sys/class$ ls
ata_device bdi devfreq firmware hwmon leds misc power_supply regulator scsi_disk spi_host tty
ata_link block dma gpio i2c-adapter mdio_bus mmc_host ppdev rfkill scsi_generic spi_master usbmon
ata_port bluetooth dmi graphics ieee80211 mem net ppp rtc scsi_host spi_transport vc
backlight bsg drm hidraw input memstick_host pci_bus printer scsi_device sound thermal vtconsole
johannes@xxodd-ubuntu:/sys/class$ cd hidraw/
pi@raspberrypi /sys/class $ ls
bdi firmware graphics input mem mmc_host raw scsi_device scsi_host spi_master tty vc vc-mem
block gpio i2c-adapter leds misc net rtc scsi_disk sound thermal usb_device vchiq vtconsole
pi@raspberrypi /sys/class $