PLT_VOL_DOWN       27 drivers/hid/hid-plantronics.c #define PLT1_VOL_DOWN		(PLT_HID_1_0_PAGE | PLT_VOL_DOWN)
PLT_VOL_DOWN       29 drivers/hid/hid-plantronics.c #define PLT2_VOL_DOWN		(PLT_HID_2_0_PAGE | PLT_VOL_DOWN)