1MediaTek GCE 2=============== 3 4The Global Command Engine (GCE) is used to help read/write registers with 5critical time limitation, such as updating display configuration during the 6vblank. The GCE can be used to implement the Command Queue (CMDQ) driver. 7 8CMDQ driver uses mailbox framework for communication. Please refer to 9mailbox.txt for generic information about mailbox device-tree bindings. 10 11Required properties: 12- compatible: can be "mediatek,mt8173-gce", "mediatek,mt8183-gce", 13 "mediatek,mt8186-gce", "mediatek,mt8192-gce", "mediatek,mt8195-gce" or 14 "mediatek,mt6779-gce". 15- reg: Address range of the GCE unit 16- interrupts: The interrupt signal from the GCE block 17- clock: Clocks according to the common clock binding 18- clock-names: Must be "gce" to stand for GCE clock 19- #mbox-cells: Should be 2. 20 <&phandle channel priority> 21 phandle: Label name of a gce node. 22 channel: Channel of mailbox. Be equal to the thread id of GCE. 23 priority: Priority of GCE thread. 24 25Required properties for a client device: 26- mboxes: Client use mailbox to communicate with GCE, it should have this 27 property and list of phandle, mailbox specifiers. 28Optional properties for a client device: 29- mediatek,gce-client-reg: Specify the sub-system id which is corresponding 30 to the register address, it should have this property and list of phandle, 31 sub-system specifiers. 32 <&phandle subsys_number start_offset size> 33 phandle: Label name of a gce node. 34 subsys_number: specify the sub-system id which is corresponding 35 to the register address. 36 start_offset: the start offset of register address that GCE can access. 37 size: the total size of register address that GCE can access. 38 39Optional properties for a client mutex node: 40- mediatek,gce-events: GCE events used by clients. The event numbers are 41 defined in 'dt-bindings/gce/<chip>-gce.h'. 42 43Some vaules of properties are defined in 'dt-bindings/gce/mt8173-gce.h', 44'dt-bindings/gce/mt8183-gce.h', 'dt-bindings/gce/mt8186-gce.h' 45'dt-bindings/gce/mt8192-gce.h', 'dt-bindings/gce/mt8195-gce.h' or 46'dt-bindings/gce/mt6779-gce.h'. 47Such as sub-system ids, thread priority, event ids. 48 49Example: 50 51 gce: gce@10212000 { 52 compatible = "mediatek,mt8173-gce"; 53 reg = <0 0x10212000 0 0x1000>; 54 interrupts = <GIC_SPI 135 IRQ_TYPE_LEVEL_LOW>; 55 clocks = <&infracfg CLK_INFRA_GCE>; 56 clock-names = "gce"; 57 #mbox-cells = <2>; 58 }; 59 60Example for a client device: 61 62 mmsys: clock-controller@14000000 { 63 compatible = "mediatek,mt8173-mmsys"; 64 mboxes = <&gce 0 CMDQ_THR_PRIO_LOWEST>, 65 <&gce 1 CMDQ_THR_PRIO_LOWEST>; 66 mutex-event-eof = <CMDQ_EVENT_MUTEX0_STREAM_EOF 67 CMDQ_EVENT_MUTEX1_STREAM_EOF>; 68 mediatek,gce-client-reg = <&gce SUBSYS_1400XXXX 0x3000 0x1000>, 69 <&gce SUBSYS_1401XXXX 0x2000 0x100>; 70 ... 71 }; 72 73Example for a client mutex node: 74 mutex: mutex@14020000 { 75 compatible = "mediatek,mt8173-disp-mutex"; 76 reg = <0 0x14020000 0 0x1000>; 77 interrupts = <GIC_SPI 169 IRQ_TYPE_LEVEL_LOW>; 78 power-domains = <&scpsys MT8173_POWER_DOMAIN_MM>; 79 clocks = <&mmsys CLK_MM_MUTEX_32K>; 80 mediatek,gce-events = <CMDQ_EVENT_MUTEX0_STREAM_EOF>, 81 <CMDQ_EVENT_MUTEX1_STREAM_EOF>; 82 }; 83