From mboxrd@z Thu Jan  1 00:00:00 1970
From: robh@kernel.org (Rob Herring)
Date: Fri, 16 Nov 2018 17:15:22 -0600
Subject: [PATCH v5 08/12] dt-bindings: mediatek: Change the binding for
 mmsys clocks
In-Reply-To: <20181116125449.23581-9-matthias.bgg@kernel.org>
References: <20181116125449.23581-1-matthias.bgg@kernel.org>
 <20181116125449.23581-9-matthias.bgg@kernel.org>
Message-ID: <20181116231522.GA18006@bogus>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Fri, Nov 16, 2018 at 01:54:45PM +0100, matthias.bgg at kernel.org wrote:
> From: Matthias Brugger <mbrugger@suse.com>
> 
> On SoCs with no publical available HW or no working graphic stack
> we change the devicetree binding for the mmsys clock part. This
> way we don't need to register a platform device explicitly in the
> drm driver. Instead we can create a mmsys child which invokes the
> clock driver.
> 
> Signed-off-by: Matthias Brugger <mbrugger@suse.com>
> ---
>  .../bindings/arm/mediatek/mediatek,mmsys.txt  | 21 ++++++++++++-------
>  .../display/mediatek/mediatek,disp.txt        |  4 ++++
>  2 files changed, 18 insertions(+), 7 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.txt b/Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.txt
> index 4468345f8b1a..d4e205981363 100644
> --- a/Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.txt
> +++ b/Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.txt
> @@ -1,4 +1,4 @@
> -Mediatek mmsys controller
> +Mediatek mmsys clock controller
>  ============================
>  
>  The Mediatek mmsys controller provides various clocks to the system.
> @@ -6,18 +6,25 @@ The Mediatek mmsys controller provides various clocks to the system.
>  Required Properties:
>  
>  - compatible: Should be one of:
> -	- "mediatek,mt2712-mmsys", "syscon"
> -	- "mediatek,mt6797-mmsys", "syscon"
> +	- "mediatek,mt2712-mmsys-clk", "syscon"
> +	- "mediatek,mt6797-mmsys-clk", "syscon"

Doesn't match the example.

>  - #clock-cells: Must be 1
>  
> -The mmsys controller uses the common clk binding from
> +The mmsys clock controller uses the common clk binding from
>  Documentation/devicetree/bindings/clock/clock-bindings.txt
>  The available clocks are defined in dt-bindings/clock/mt*-clk.h.
> +It is a child of the mmsys block, see binding at:
> +Documentation/devicetree/bindings/display/mediatek/mediatek,disp.txt
>  
>  Example:
>  
> -mmsys: clock-controller at 14000000 {
> -	compatible = "mediatek,mt8173-mmsys", "syscon";
> +mmsys: syscon at 14000000 {
> +	compatible = "mediatek,mt2712-mmsys", "syscon", "simple-mfd";
>  	reg = <0 0x14000000 0 0x1000>;
> -	#clock-cells = <1>;
> +
> +	mmsys_clk: clock-controller at 14000000 {
> +		compatible = "mediatek,mt2712-mmsys-clk";
> +		#clock-cells = <1>;

This goes against the general direction of not defining separate nodes 
for providers with no resources.

Why do you need this and what does it buy if you have to continue to 
support the existing chips?

Rob