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