$ ioreg -c AppleDisplay -r -d 1

output

+-o AppleDisplay  <class AppleDisplay, id 0x10000159e, registered, matched, active, busy 0 (0 ms), retain 9>
    {
      "IOClass" = "AppleDisplay"
      "DisplayParameterHandlerUsesCharPtr" = Yes
      "IODisplayPrefsKey" = "IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IGPU@2/AppleIntelFramebuffer@1/display0/AppleDisplay-610-9227"
      "IODisplayEDID" = <…>
      "IODisplayTechnologyType" = <00ff0203>
      "IODisplayControllerID" = <000000ff>
      "IOProviderClass" = "IODisplayConnect"
      "IODisplayFirmwareLevel" = <ffff0138>
      "DisplaySerialNumber" = …
      "IOPowerManagement" = {"DevicePowerState"=3,"CapabilityFlags"=49152,"CurrentPowerState"=3,"MaxPowerState"=3}
      "IOProbeScore" = 2000
      "IODisplayCapabilityString" = <"prot(monitor) type(LCD) model(Thunderbolt Display) cmds(01 02 03 E3 F3) VCP(02 05 10 52 62 66 8D 93 B6 C0 C8 C9 CA D6(01 02 03 04) DF E9 EB ED FD) mccs_ver(2.2)">
      "IODisplayUsageTime" = <00000000>
      "IOMatchCategory" = "IODefaultMatchCategory"
      "CFBundleIdentifier" = "com.apple.iokit.IOGraphicsFamily"
      "DisplayProductID" = 37415
      "IODisplayParameters" = {"commit"={"min"=0,"max"=0,"value"=0},"audio-mute-and-screen-blank"={"min"=0,"max"=514,"value"=514},"ggsc"={"min"=0,"max"=65536,"value"=65536},"gsc "={"min"=0,"max"=65536,"value"=65536},"ambient-light-sensor"={"min"=0,"max"=2,"value"=2},"vblm"={"min"=0,"max"=196608,"value"=65536},"dsyp"={"min"=0,"max"=2,"value"=2},"rgsc"={"min"=0,"max"=65536,"value"=65536},"audio-balance-LR"={"min"=0,"max"=254,"value"=128},"bgsc"={"min"=0,"max"=65536,"value"=65536},"cyuv"={"min"=0,"max"=268435456,"value"=268435456},"cmod"={"min"=0,"max"=4096,"value"=1},"colr"={"min"=0,"max"=18446744073709551615,"value"=257},"speaker-volume"={"min"=0,"max"=255,"value"=155},"brightness"={"min"=0,"max"=65535,"value"=25001},"brightness-fade"={"min"=0,"max"=65534,"value"=0},"power-mode"={"min"=0,"max"=4,"value"=4}}
      "DisplayVendorID" = 1552
      "IODisplayMCCSVersion" = <00020200>
      "IODisplayConnectFlags" = <00000000>
      "IODisplayAttributes" = {"IODisplayAttributes"=<676174760000000073676c6600000000726c6f630100000063706220060000006364670080808000676c666400000000>}
      "IOGeneralInterest" = "IOCommand is not serializable"
    }