diff mbox

[v22,1/4] dt-bindings: soc: Add documentation for the MediaTek GCE unit

Message ID 1530098172-31385-2-git-send-email-houlong.wei@mediatek.com (mailing list archive)
State New, archived
Headers show

Commit Message

houlong.wei June 27, 2018, 11:16 a.m. UTC
This adds documentation for the MediaTek Global Command Engine (GCE) unit
found in MT8173 SoCs.

Signed-off-by: Houlong Wei <houlong.wei@mediatek.com>
Signed-off-by: HS Liao <hs.liao@mediatek.com>
---
Hi Rob,
  I don't add your ACK in this version since the dt-binding description
has been changed. Thanks.
---
 .../devicetree/bindings/mailbox/mtk-gce.txt        |   65 ++++++++++++++++++++
 include/dt-bindings/gce/mt8173-gce.h               |   48 +++++++++++++++
 2 files changed, 113 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mailbox/mtk-gce.txt
 create mode 100644 include/dt-bindings/gce/mt8173-gce.h

Comments

Rob Herring (Arm) July 3, 2018, 2:30 a.m. UTC | #1
On Wed, Jun 27, 2018 at 07:16:09PM +0800, Houlong Wei wrote:
> This adds documentation for the MediaTek Global Command Engine (GCE) unit
> found in MT8173 SoCs.
> 
> Signed-off-by: Houlong Wei <houlong.wei@mediatek.com>
> Signed-off-by: HS Liao <hs.liao@mediatek.com>
> ---
> Hi Rob,
>   I don't add your ACK in this version since the dt-binding description
> has been changed. Thanks.
> ---
>  .../devicetree/bindings/mailbox/mtk-gce.txt        |   65 ++++++++++++++++++++
>  include/dt-bindings/gce/mt8173-gce.h               |   48 +++++++++++++++
>  2 files changed, 113 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mailbox/mtk-gce.txt
>  create mode 100644 include/dt-bindings/gce/mt8173-gce.h
> 
> diff --git a/Documentation/devicetree/bindings/mailbox/mtk-gce.txt b/Documentation/devicetree/bindings/mailbox/mtk-gce.txt
> new file mode 100644
> index 0000000..26f65a4
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mailbox/mtk-gce.txt
> @@ -0,0 +1,65 @@
> +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
> +- thread-num: Maximum threads count of GCE.

mediatek,thread-num

Is this needed for anything other than error checking the thread id in 
the mbox cells? if that's it, then drop it. 

> +- #mbox-cells: Should be 4.
> +	<&phandle channel timeout priority atomic_exec>
> +	phandle: Label name of a gce node.
> +	channel: Channel of mailbox. Be equal to the thread id of GCE.
> +	timeout: Maximum time of software waiting GCE processing done, in unit
> +		of millisecond.
> +	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.
> +- gce-subsys: Specify the sub-system id which is corresponding to the register
> +  address.

What is this for?

> +
> +Optional properties for a client device:
> +- gce-event: Specify the event if the client has any. Because the event is
> +  parsed by client, so client can replace 'gce-event' with other meaningful
> +  name.

If the client sets the name, then no point having here. It must be 
documented in the client binding. But then, what is this for in the 
first place?

> +
> +Some vaules of properties are defined in 'dt-bindings/gce/mt8173-gce.h'. Such as
> +thread number, sub-system ids, thread priority, event ids.
> +
> +Example:
> +
> +	gce: gce@10212000 {

mailbox@...

> +		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 = <4>;
> +	};
> +
> +Example for a client device:
> +
> +	mmsys: clock-controller@14000000 {
> +		compatible = "mediatek,mt8173-mmsys";
> +		mboxes = <&gce 0 2000 CMDQ_THR_PRIO_LOWEST 1>,
> +			 <&gce 1 2000 CMDQ_THR_PRIO_LOWEST 1>;
> +		gce-subsys = <SUBSYS_1400XXXX>;
> +		mutex-event-eof = <CMDQ_EVENT_MUTEX0_STREAM_EOF
> +				CMDQ_EVENT_MUTEX1_STREAM_EOF>;
> +
> +		...
> +	};
houlong.wei July 3, 2018, 11:39 p.m. UTC | #2
On Tue, 2018-07-03 at 10:30 +0800, Rob Herring wrote:
> On Wed, Jun 27, 2018 at 07:16:09PM +0800, Houlong Wei wrote:
> > This adds documentation for the MediaTek Global Command Engine (GCE) unit
> > found in MT8173 SoCs.
> > 
> > Signed-off-by: Houlong Wei <houlong.wei@mediatek.com>
> > Signed-off-by: HS Liao <hs.liao@mediatek.com>
> > ---
> > Hi Rob,
> >   I don't add your ACK in this version since the dt-binding description
> > has been changed. Thanks.
> > ---
> >  .../devicetree/bindings/mailbox/mtk-gce.txt        |   65 ++++++++++++++++++++
> >  include/dt-bindings/gce/mt8173-gce.h               |   48 +++++++++++++++
> >  2 files changed, 113 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/mailbox/mtk-gce.txt
> >  create mode 100644 include/dt-bindings/gce/mt8173-gce.h
> > 
> > diff --git a/Documentation/devicetree/bindings/mailbox/mtk-gce.txt b/Documentation/devicetree/bindings/mailbox/mtk-gce.txt
> > new file mode 100644
> > index 0000000..26f65a4
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mailbox/mtk-gce.txt
> > @@ -0,0 +1,65 @@
> > +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
> > +- thread-num: Maximum threads count of GCE.
> 
> mediatek,thread-num
> 
> Is this needed for anything other than error checking the thread id in 
> the mbox cells? if that's it, then drop it. 
> 

'thread-num' is used to configure the GCE thread number, which is the
channel number of gce mailbox. This property is read in
cmdq_probe()/mtk-cmdq-mailbox.c and a mailbox's channel array is
allocated according to the number.
Since the thread number may be different on different SoC, we wish it
could be configured in device tree.

> > +- #mbox-cells: Should be 4.
> > +	<&phandle channel timeout priority atomic_exec>
> > +	phandle: Label name of a gce node.
> > +	channel: Channel of mailbox. Be equal to the thread id of GCE.
> > +	timeout: Maximum time of software waiting GCE processing done, in unit
> > +		of millisecond.
> > +	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.
> > +- gce-subsys: Specify the sub-system id which is corresponding to the register
> > +  address.
> 
> What is this for?

You mean the new added property 'gce-subsys'?  
It is used for GCE to distinguish the high 16-bit of a hardware register
address. When a client driver packets a register setting into a GCE
instruction, it uses a sub-system code and register offset instead of
the 32-bit register address.
Since sub-system code may be different on different SoC, we wish it
could be configured in device tree.

> 
> > +
> > +Optional properties for a client device:
> > +- gce-event: Specify the event if the client has any. Because the event is
> > +  parsed by client, so client can replace 'gce-event' with other meaningful
> > +  name.
> 
> If the client sets the name, then no point having here. It must be 
> documented in the client binding. But then, what is this for in the 
> first place?

Since display driver will use GCE firstly, so we will move the
description to
'Documentation/devicetree/bindings/display/mediatek/mediatek,disp.txt'
when display driver start using the GCE driver.
Is that ok?

> 
> > +
> > +Some vaules of properties are defined in 'dt-bindings/gce/mt8173-gce.h'. Such as
> > +thread number, sub-system ids, thread priority, event ids.
> > +
> > +Example:
> > +
> > +	gce: gce@10212000 {
> 
> mailbox@...

Will do.

> 
> > +		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 = <4>;
> > +	};
> > +
> > +Example for a client device:
> > +
> > +	mmsys: clock-controller@14000000 {
> > +		compatible = "mediatek,mt8173-mmsys";
> > +		mboxes = <&gce 0 2000 CMDQ_THR_PRIO_LOWEST 1>,
> > +			 <&gce 1 2000 CMDQ_THR_PRIO_LOWEST 1>;
> > +		gce-subsys = <SUBSYS_1400XXXX>;
> > +		mutex-event-eof = <CMDQ_EVENT_MUTEX0_STREAM_EOF
> > +				CMDQ_EVENT_MUTEX1_STREAM_EOF>;
> > +
> > +		...
> > +	};
Rob Herring (Arm) July 5, 2018, 8:08 p.m. UTC | #3
On Tue, Jul 3, 2018 at 5:39 PM houlong wei <houlong.wei@mediatek.com> wrote:
>
> On Tue, 2018-07-03 at 10:30 +0800, Rob Herring wrote:
> > On Wed, Jun 27, 2018 at 07:16:09PM +0800, Houlong Wei wrote:
> > > This adds documentation for the MediaTek Global Command Engine (GCE) unit
> > > found in MT8173 SoCs.
> > >
> > > Signed-off-by: Houlong Wei <houlong.wei@mediatek.com>
> > > Signed-off-by: HS Liao <hs.liao@mediatek.com>
> > > ---
> > > Hi Rob,
> > >   I don't add your ACK in this version since the dt-binding description
> > > has been changed. Thanks.
> > > ---
> > >  .../devicetree/bindings/mailbox/mtk-gce.txt        |   65 ++++++++++++++++++++
> > >  include/dt-bindings/gce/mt8173-gce.h               |   48 +++++++++++++++
> > >  2 files changed, 113 insertions(+)
> > >  create mode 100644 Documentation/devicetree/bindings/mailbox/mtk-gce.txt
> > >  create mode 100644 include/dt-bindings/gce/mt8173-gce.h
> > >
> > > diff --git a/Documentation/devicetree/bindings/mailbox/mtk-gce.txt b/Documentation/devicetree/bindings/mailbox/mtk-gce.txt
> > > new file mode 100644
> > > index 0000000..26f65a4
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/mailbox/mtk-gce.txt
> > > @@ -0,0 +1,65 @@
> > > +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
> > > +- thread-num: Maximum threads count of GCE.
> >
> > mediatek,thread-num
> >
> > Is this needed for anything other than error checking the thread id in
> > the mbox cells? if that's it, then drop it.
> >
>
> 'thread-num' is used to configure the GCE thread number, which is the
> channel number of gce mailbox. This property is read in
> cmdq_probe()/mtk-cmdq-mailbox.c and a mailbox's channel array is
> allocated according to the number.
> Since the thread number may be different on different SoC, we wish it
> could be configured in device tree.

You should have different compatible strings for different SoCs and
can imply the number of threads from that.

Or if the number of threads doesn't vary greatly, just allocate the
max # of channels. Or allocate the per thread data when a thread is
actually in use.

>
> > > +- #mbox-cells: Should be 4.
> > > +   <&phandle channel timeout priority atomic_exec>
> > > +   phandle: Label name of a gce node.
> > > +   channel: Channel of mailbox. Be equal to the thread id of GCE.
> > > +   timeout: Maximum time of software waiting GCE processing done, in unit
> > > +           of millisecond.
> > > +   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.
> > > +- gce-subsys: Specify the sub-system id which is corresponding to the register
> > > +  address.
> >
> > What is this for?
>
> You mean the new added property 'gce-subsys'?
> It is used for GCE to distinguish the high 16-bit of a hardware register
> address. When a client driver packets a register setting into a GCE
> instruction, it uses a sub-system code and register offset instead of
> the 32-bit register address.
> Since sub-system code may be different on different SoC, we wish it
> could be configured in device tree.

Okay. It needs a vendor prefix and to specify the size and type of the value.

>
> >
> > > +
> > > +Optional properties for a client device:
> > > +- gce-event: Specify the event if the client has any. Because the event is
> > > +  parsed by client, so client can replace 'gce-event' with other meaningful
> > > +  name.
> >
> > If the client sets the name, then no point having here. It must be
> > documented in the client binding. But then, what is this for in the
> > first place?
>
> Since display driver will use GCE firstly, so we will move the
> description to
> 'Documentation/devicetree/bindings/display/mediatek/mediatek,disp.txt'
> when display driver start using the GCE driver.
> Is that ok?

Not sure. I don't understand how it is used.

> > > +
> > > +Some vaules of properties are defined in 'dt-bindings/gce/mt8173-gce.h'. Such as
> > > +thread number, sub-system ids, thread priority, event ids.
> > > +
> > > +Example:
> > > +
> > > +   gce: gce@10212000 {
> >
> > mailbox@...
>
> Will do.
>
> >
> > > +           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 = <4>;
> > > +   };
> > > +
> > > +Example for a client device:
> > > +
> > > +   mmsys: clock-controller@14000000 {
> > > +           compatible = "mediatek,mt8173-mmsys";
> > > +           mboxes = <&gce 0 2000 CMDQ_THR_PRIO_LOWEST 1>,
> > > +                    <&gce 1 2000 CMDQ_THR_PRIO_LOWEST 1>;
> > > +           gce-subsys = <SUBSYS_1400XXXX>;
> > > +           mutex-event-eof = <CMDQ_EVENT_MUTEX0_STREAM_EOF
> > > +                           CMDQ_EVENT_MUTEX1_STREAM_EOF>;
> > > +
> > > +           ...
> > > +   };
>
>
> --
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houlong.wei July 6, 2018, 2:29 a.m. UTC | #4
On Fri, 2018-07-06 at 04:08 +0800, Rob Herring wrote:
> On Tue, Jul 3, 2018 at 5:39 PM houlong wei <houlong.wei@mediatek.com> wrote:
> >
> > On Tue, 2018-07-03 at 10:30 +0800, Rob Herring wrote:
> > > On Wed, Jun 27, 2018 at 07:16:09PM +0800, Houlong Wei wrote:
> > > > This adds documentation for the MediaTek Global Command Engine (GCE) unit
> > > > found in MT8173 SoCs.
> > > >
> > > > Signed-off-by: Houlong Wei <houlong.wei@mediatek.com>
> > > > Signed-off-by: HS Liao <hs.liao@mediatek.com>
> > > > ---
> > > > Hi Rob,
> > > >   I don't add your ACK in this version since the dt-binding description
> > > > has been changed. Thanks.
> > > > ---
> > > >  .../devicetree/bindings/mailbox/mtk-gce.txt        |   65 ++++++++++++++++++++
> > > >  include/dt-bindings/gce/mt8173-gce.h               |   48 +++++++++++++++
> > > >  2 files changed, 113 insertions(+)
> > > >  create mode 100644 Documentation/devicetree/bindings/mailbox/mtk-gce.txt
> > > >  create mode 100644 include/dt-bindings/gce/mt8173-gce.h
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/mailbox/mtk-gce.txt b/Documentation/devicetree/bindings/mailbox/mtk-gce.txt
> > > > new file mode 100644
> > > > index 0000000..26f65a4
> > > > --- /dev/null
> > > > +++ b/Documentation/devicetree/bindings/mailbox/mtk-gce.txt
> > > > @@ -0,0 +1,65 @@
> > > > +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
> > > > +- thread-num: Maximum threads count of GCE.
> > >
> > > mediatek,thread-num
> > >
> > > Is this needed for anything other than error checking the thread id in
> > > the mbox cells? if that's it, then drop it.
> > >
> >
> > 'thread-num' is used to configure the GCE thread number, which is the
> > channel number of gce mailbox. This property is read in
> > cmdq_probe()/mtk-cmdq-mailbox.c and a mailbox's channel array is
> > allocated according to the number.
> > Since the thread number may be different on different SoC, we wish it
> > could be configured in device tree.
> 
> You should have different compatible strings for different SoCs and
> can imply the number of threads from that.
> 

Thanks. Will remove 'thread-num' form device tree and put it in match
table of cmdq dirver.

> Or if the number of threads doesn't vary greatly, just allocate the
> max # of channels. Or allocate the per thread data when a thread is
> actually in use.
> 
> >
> > > > +- #mbox-cells: Should be 4.
> > > > +   <&phandle channel timeout priority atomic_exec>
> > > > +   phandle: Label name of a gce node.
> > > > +   channel: Channel of mailbox. Be equal to the thread id of GCE.
> > > > +   timeout: Maximum time of software waiting GCE processing done, in unit
> > > > +           of millisecond.
> > > > +   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.
> > > > +- gce-subsys: Specify the sub-system id which is corresponding to the register
> > > > +  address.
> > >
> > > What is this for?
> >
> > You mean the new added property 'gce-subsys'?
> > It is used for GCE to distinguish the high 16-bit of a hardware register
> > address. When a client driver packets a register setting into a GCE
> > instruction, it uses a sub-system code and register offset instead of
> > the 32-bit register address.
> > Since sub-system code may be different on different SoC, we wish it
> > could be configured in device tree.
> 
> Okay. It needs a vendor prefix and to specify the size and type of the value.
> 

Will do.

> >
> > >
> > > > +
> > > > +Optional properties for a client device:
> > > > +- gce-event: Specify the event if the client has any. Because the event is
> > > > +  parsed by client, so client can replace 'gce-event' with other meaningful
> > > > +  name.
> > >
> > > If the client sets the name, then no point having here. It must be
> > > documented in the client binding. But then, what is this for in the
> > > first place?
> >
> > Since display driver will use GCE firstly, so we will move the
> > description to
> > 'Documentation/devicetree/bindings/display/mediatek/mediatek,disp.txt'
> > when display driver start using the GCE driver.
> > Is that ok?
> 
> Not sure. I don't understand how it is used.
> 
> > > > +
> > > > +Some vaules of properties are defined in 'dt-bindings/gce/mt8173-gce.h'. Such as
> > > > +thread number, sub-system ids, thread priority, event ids.
> > > > +
> > > > +Example:
> > > > +
> > > > +   gce: gce@10212000 {
> > >
> > > mailbox@...
> >
> > Will do.
> >
> > >
> > > > +           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 = <4>;
> > > > +   };
> > > > +
> > > > +Example for a client device:
> > > > +
> > > > +   mmsys: clock-controller@14000000 {
> > > > +           compatible = "mediatek,mt8173-mmsys";
> > > > +           mboxes = <&gce 0 2000 CMDQ_THR_PRIO_LOWEST 1>,
> > > > +                    <&gce 1 2000 CMDQ_THR_PRIO_LOWEST 1>;
> > > > +           gce-subsys = <SUBSYS_1400XXXX>;
> > > > +           mutex-event-eof = <CMDQ_EVENT_MUTEX0_STREAM_EOF
> > > > +                           CMDQ_EVENT_MUTEX1_STREAM_EOF>;
> > > > +
> > > > +           ...
> > > > +   };
> >
> >
> > --
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> > the body of a message to majordomo@vger.kernel.org
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diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/mailbox/mtk-gce.txt b/Documentation/devicetree/bindings/mailbox/mtk-gce.txt
new file mode 100644
index 0000000..26f65a4
--- /dev/null
+++ b/Documentation/devicetree/bindings/mailbox/mtk-gce.txt
@@ -0,0 +1,65 @@ 
+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
+- thread-num: Maximum threads count of GCE.
+- #mbox-cells: Should be 4.
+	<&phandle channel timeout priority atomic_exec>
+	phandle: Label name of a gce node.
+	channel: Channel of mailbox. Be equal to the thread id of GCE.
+	timeout: Maximum time of software waiting GCE processing done, in unit
+		of millisecond.
+	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.
+- gce-subsys: Specify the sub-system id which is corresponding to the register
+  address.
+
+Optional properties for a client device:
+- gce-event: Specify the event if the client has any. Because the event is
+  parsed by client, so client can replace 'gce-event' with other meaningful
+  name.
+
+Some vaules of properties are defined in 'dt-bindings/gce/mt8173-gce.h'. Such as
+thread number, 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 = <4>;
+	};
+
+Example for a client device:
+
+	mmsys: clock-controller@14000000 {
+		compatible = "mediatek,mt8173-mmsys";
+		mboxes = <&gce 0 2000 CMDQ_THR_PRIO_LOWEST 1>,
+			 <&gce 1 2000 CMDQ_THR_PRIO_LOWEST 1>;
+		gce-subsys = <SUBSYS_1400XXXX>;
+		mutex-event-eof = <CMDQ_EVENT_MUTEX0_STREAM_EOF
+				CMDQ_EVENT_MUTEX1_STREAM_EOF>;
+
+		...
+	};
diff --git a/include/dt-bindings/gce/mt8173-gce.h b/include/dt-bindings/gce/mt8173-gce.h
new file mode 100644
index 0000000..89eb3b8
--- /dev/null
+++ b/include/dt-bindings/gce/mt8173-gce.h
@@ -0,0 +1,48 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2018 MediaTek Inc.
+ * Author: Houlong Wei <houlong.wei@mediatek.com>
+ *
+ */
+
+#ifndef _DT_BINDINGS_GCE_MT8173_H
+#define _DT_BINDINGS_GCE_MT8173_H
+
+#define CMDQ_NO_TIMEOUT		0xffffffff
+
+#define CMDQ_THR_MAX_COUNT	16
+
+/* GCE HW thread priority */
+#define CMDQ_THR_PRIO_LOWEST	0
+#define CMDQ_THR_PRIO_HIGHEST	1
+
+/* GCE SUBSYS */
+#define SUBSYS_1400XXXX		1
+#define SUBSYS_1401XXXX		2
+#define SUBSYS_1402XXXX		3
+
+/* GCE HW EVENT */
+#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
+
+#endif