diff mbox

[v2,2/6] mfd: dt: Add bindings for the Aspeed SoC Display Controller (GFX)

Message ID 1478097481-14895-3-git-send-email-andrew@aj.id.au
State Not Applicable, archived
Headers show

Commit Message

Andrew Jeffery Nov. 2, 2016, 2:37 p.m. UTC
The Aspeed SoC Display Controller is presented as a syscon device to
arbitrate access by display and pinmux drivers. Video pinmux
configuration on fifth generation SoCs depends on bits in both the
System Control Unit and the Display Controller.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
---
 Documentation/devicetree/bindings/mfd/aspeed-gfx.txt | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/aspeed-gfx.txt

Comments

Rob Herring (Arm) Nov. 9, 2016, 6:26 p.m. UTC | #1
On Thu, Nov 03, 2016 at 01:07:57AM +1030, Andrew Jeffery wrote:
> The Aspeed SoC Display Controller is presented as a syscon device to
> arbitrate access by display and pinmux drivers. Video pinmux
> configuration on fifth generation SoCs depends on bits in both the
> System Control Unit and the Display Controller.
> 
> Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
> ---
>  Documentation/devicetree/bindings/mfd/aspeed-gfx.txt | 17 +++++++++++++++++

The register space can't be split to 2 nodes? 

>  1 file changed, 17 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mfd/aspeed-gfx.txt
> 
> diff --git a/Documentation/devicetree/bindings/mfd/aspeed-gfx.txt b/Documentation/devicetree/bindings/mfd/aspeed-gfx.txt
> new file mode 100644
> index 000000000000..aea5370efd97
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mfd/aspeed-gfx.txt
> @@ -0,0 +1,17 @@
> +* Device tree bindings for Aspeed SoC Display Controller (GFX)
> +
> +The Aspeed SoC Display Controller primarily does as its name suggests, but also
> +participates in pinmux requests on the g5 SoCs. It is therefore considered a
> +syscon device.
> +
> +Required properties:
> +- compatible:		"aspeed,ast2500-gfx", "syscon"

I think perhaps we should drop the syscon here and the driver should 
just register as a syscon.

Rob
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Joel Stanley Nov. 10, 2016, 3:19 a.m. UTC | #2
On Thu, Nov 10, 2016 at 4:56 AM, Rob Herring <robh@kernel.org> wrote:
> On Thu, Nov 03, 2016 at 01:07:57AM +1030, Andrew Jeffery wrote:
>> The Aspeed SoC Display Controller is presented as a syscon device to
>> arbitrate access by display and pinmux drivers. Video pinmux
>> configuration on fifth generation SoCs depends on bits in both the
>> System Control Unit and the Display Controller.
>>
>> Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
>> ---
>>  Documentation/devicetree/bindings/mfd/aspeed-gfx.txt | 17 +++++++++++++++++
>
> The register space can't be split to 2 nodes?

Do you mean splitting the GFX IP and enable register into two nodes?

We can't. Pinmux needs to check bit 6 and 7 in GFX064, which is in the
middle the IP block:

GFX060: CRT Control Register I
GFX064: CRT Control Register II
GFX068: CRT Status Register
GFX06C: CRT Misc Setting Register

>> +The Aspeed SoC Display Controller primarily does as its name suggests, but also
>> +participates in pinmux requests on the g5 SoCs. It is therefore considered a
>> +syscon device.
>> +
>> +Required properties:
>> +- compatible:                "aspeed,ast2500-gfx", "syscon"
>
> I think perhaps we should drop the syscon here and the driver should
> just register as a syscon.

We want the regmap to be present whenever the GFX driver or pinmux is
loaded. If we register it in pinmux but chose to not build in that
driver, we lack the regmap. Same for the case where a user builds in
the GFX driver and not pinmux. I think this means we want the syscon
compatible string, unless my understanding is wrong?

Cheers,

Joel
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Rob Herring (Arm) Nov. 10, 2016, 5:40 p.m. UTC | #3
On Wed, Nov 9, 2016 at 9:19 PM, Joel Stanley <joel@jms.id.au> wrote:
> On Thu, Nov 10, 2016 at 4:56 AM, Rob Herring <robh@kernel.org> wrote:
>> On Thu, Nov 03, 2016 at 01:07:57AM +1030, Andrew Jeffery wrote:
>>> The Aspeed SoC Display Controller is presented as a syscon device to
>>> arbitrate access by display and pinmux drivers. Video pinmux
>>> configuration on fifth generation SoCs depends on bits in both the
>>> System Control Unit and the Display Controller.
>>>
>>> Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
>>> ---
>>>  Documentation/devicetree/bindings/mfd/aspeed-gfx.txt | 17 +++++++++++++++++
>>
>> The register space can't be split to 2 nodes?
>
> Do you mean splitting the GFX IP and enable register into two nodes?
>
> We can't. Pinmux needs to check bit 6 and 7 in GFX064, which is in the
> middle the IP block:
>
> GFX060: CRT Control Register I
> GFX064: CRT Control Register II
> GFX068: CRT Status Register
> GFX06C: CRT Misc Setting Register

Okay.

>>> +The Aspeed SoC Display Controller primarily does as its name suggests, but also
>>> +participates in pinmux requests on the g5 SoCs. It is therefore considered a
>>> +syscon device.
>>> +
>>> +Required properties:
>>> +- compatible:                "aspeed,ast2500-gfx", "syscon"
>>
>> I think perhaps we should drop the syscon here and the driver should
>> just register as a syscon.
>
> We want the regmap to be present whenever the GFX driver or pinmux is
> loaded. If we register it in pinmux but chose to not build in that
> driver, we lack the regmap. Same for the case where a user builds in
> the GFX driver and not pinmux. I think this means we want the syscon
> compatible string, unless my understanding is wrong?

Right.

Acked-by: Rob Herring <robh@kernel.org>

Rob
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Lee Jones Nov. 18, 2016, 6:47 p.m. UTC | #4
On Thu, 03 Nov 2016, Andrew Jeffery wrote:

> The Aspeed SoC Display Controller is presented as a syscon device to
> arbitrate access by display and pinmux drivers. Video pinmux
> configuration on fifth generation SoCs depends on bits in both the
> System Control Unit and the Display Controller.
> 
> Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
> ---
>  Documentation/devicetree/bindings/mfd/aspeed-gfx.txt | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mfd/aspeed-gfx.txt

Same here.

> diff --git a/Documentation/devicetree/bindings/mfd/aspeed-gfx.txt b/Documentation/devicetree/bindings/mfd/aspeed-gfx.txt
> new file mode 100644
> index 000000000000..aea5370efd97
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mfd/aspeed-gfx.txt
> @@ -0,0 +1,17 @@
> +* Device tree bindings for Aspeed SoC Display Controller (GFX)
> +
> +The Aspeed SoC Display Controller primarily does as its name suggests, but also
> +participates in pinmux requests on the g5 SoCs. It is therefore considered a
> +syscon device.
> +
> +Required properties:
> +- compatible:		"aspeed,ast2500-gfx", "syscon"
> +- reg:			contains offset/length value of the GFX memory
> +			region.
> +
> +Example:
> +
> +gfx: display@1e6e6000 {
> +	compatible = "aspeed,ast2500-gfx", "syscon";
> +	reg = <0x1e6e6000 0x1000>;
> +};
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/mfd/aspeed-gfx.txt b/Documentation/devicetree/bindings/mfd/aspeed-gfx.txt
new file mode 100644
index 000000000000..aea5370efd97
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/aspeed-gfx.txt
@@ -0,0 +1,17 @@ 
+* Device tree bindings for Aspeed SoC Display Controller (GFX)
+
+The Aspeed SoC Display Controller primarily does as its name suggests, but also
+participates in pinmux requests on the g5 SoCs. It is therefore considered a
+syscon device.
+
+Required properties:
+- compatible:		"aspeed,ast2500-gfx", "syscon"
+- reg:			contains offset/length value of the GFX memory
+			region.
+
+Example:
+
+gfx: display@1e6e6000 {
+	compatible = "aspeed,ast2500-gfx", "syscon";
+	reg = <0x1e6e6000 0x1000>;
+};