MediaTek GCE

===============

The Global Command Engine (GCE) is used to help read/write registers with

critical time limitation, such as updating display configuration during the

vblank. The GCE can be used to implement the Command Queue (CMDQ) driver.

CMDQ driver uses mailbox framework for communication. Please refer to

mailbox.txt for generic information about mailbox device-tree bindings.

Required properties:

- compatible: Must be "mediatek,mt8173-gce"

- reg: Address range of the GCE unit

- interrupts: The interrupt signal from the GCE block

- clock: Clocks according to the common clock binding

- clock-names: Must be "gce" to stand for GCE clock

- #mbox-cells: Should be 3.

<&phandle channel priority atomic_exec>

phandle: Label name of a gce node.

channel: Channel of mailbox. Be equal to the thread id of GCE.

priority: Priority of GCE thread.

atomic_exec: GCE processing continuous packets of commands in atomic

way.

Required properties for a client device:

- mboxes: Client use mailbox to communicate with GCE, it should have this

property and list of phandle, mailbox specifiers.

- mediatek,gce-subsys: u32, specify the sub-system id which is corresponding

to the register address.

Some vaules of properties are defined in 'dt-bindings/gce/mt8173-gce.h'. Such as

sub-system ids, thread priority, event ids.

Example:

gce: gce@10212000 {

compatible = "mediatek,mt8173-gce";

reg = <0 0x10212000 0 0x1000>;

interrupts = <GIC_SPI 135 IRQ_TYPE_LEVEL_LOW>;

clocks = <&infracfg CLK_INFRA_GCE>;

clock-names = "gce";

thread-num = CMDQ_THR_MAX_COUNT;

#mbox-cells = <3>;

};

Example for a client device:

mmsys: clock-controller@14000000 {

compatible = "mediatek,mt8173-mmsys";

mboxes = <&gce 0 CMDQ_THR_PRIO_LOWEST 1>,

<&gce 1 CMDQ_THR_PRIO_LOWEST 1>;

mediatek,gce-subsys = <SUBSYS_1400XXXX>;

mutex-event-eof = <CMDQ_EVENT_MUTEX0_STREAM_EOF

CMDQ_EVENT_MUTEX1_STREAM_EOF>;

...

};

#ifndef _DT_BINDINGS_GCE_MT8173_H

#define _DT_BINDINGS_GCE_MT8173_H

#define CMDQ_THR_PRIO_LOWEST 0

#define CMDQ_THR_PRIO_HIGHEST 1

#define SUBSYS_1400XXXX 1

#define SUBSYS_1401XXXX 2

#define SUBSYS_1402XXXX 3

#define CMDQ_EVENT_DISP_OVL0_SOF 11

#define CMDQ_EVENT_DISP_OVL1_SOF 12

#define CMDQ_EVENT_DISP_RDMA0_SOF 13

#define CMDQ_EVENT_DISP_RDMA1_SOF 14

#define CMDQ_EVENT_DISP_RDMA2_SOF 15

#define CMDQ_EVENT_DISP_WDMA0_SOF 16

#define CMDQ_EVENT_DISP_WDMA1_SOF 17

#define CMDQ_EVENT_DISP_OVL0_EOF 39

#define CMDQ_EVENT_DISP_OVL1_EOF 40

#define CMDQ_EVENT_DISP_RDMA0_EOF 41

#define CMDQ_EVENT_DISP_RDMA1_EOF 42

#define CMDQ_EVENT_DISP_RDMA2_EOF 43

#define CMDQ_EVENT_DISP_WDMA0_EOF 44

#define CMDQ_EVENT_DISP_WDMA1_EOF 45

#define CMDQ_EVENT_MUTEX0_STREAM_EOF 53

#define CMDQ_EVENT_MUTEX1_STREAM_EOF 54

#define CMDQ_EVENT_MUTEX2_STREAM_EOF 55

#define CMDQ_EVENT_MUTEX3_STREAM_EOF 56

#define CMDQ_EVENT_MUTEX4_STREAM_EOF 57

#define CMDQ_EVENT_DISP_RDMA0_UNDERRUN 63

#define CMDQ_EVENT_DISP_RDMA1_UNDERRUN 64

#define CMDQ_EVENT_DISP_RDMA2_UNDERRUN 65