[PATCH 1/3 repost] clocksource: sh_cmt: Document SoC specific bindings

Mark Rutland mark.rutland at arm.com
Wed Aug 27 02:51:03 PDT 2014


Hi Simon,

On Wed, Aug 27, 2014 at 06:28:18AM +0100, Simon Horman wrote:
> In general Renesas hardware is not documented to the extent
> where the relationship between IP blocks on different SoCs can be assumed
> although they may appear to operate the same way. Furthermore the
> documentation typically does not specify a version for individual
> IP blocks. For these reasons a convention of using the SoC name in place
> of a version and providing SoC-specific compat strings has been adopted.
> 
> Although not universally liked this convention is used in the bindings
> for the drivers a number of drivers for Renesas hardware. The purpose
> of this patch is to update the Renesas R-Car Compare Match Timer (CMT)
> driver to follow this convention.

Having really specific strings to give us the flexibility if necessary
makes sense, so I the addition of the strings below is fine.

I see in the example update the existing "renesas,cmt-48-gen2" string
remains. I take it we expect that as a fallback in the compatible list
for all of the new strings, and the driver can jsut match on that for
the moment?

If so, it would be nice to be more explicit as to what we expect as
fallback compatible entries.

Cheers,
Mark.

> 
> Signed-off-by: Simon Horman <horms+renesas at verge.net.au>
> 
> ---
> * I plan to follow up with patches to use these new bindings in the
>   dtsi files for the affected SoCs.
> ---
>  .../devicetree/bindings/timer/renesas,cmt.txt      | 26 +++++++++++++++++++++-
>  1 file changed, 25 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/timer/renesas,cmt.txt b/Documentation/devicetree/bindings/timer/renesas,cmt.txt
> index a17418b..500bad2 100644
> --- a/Documentation/devicetree/bindings/timer/renesas,cmt.txt
> +++ b/Documentation/devicetree/bindings/timer/renesas,cmt.txt
> @@ -16,10 +16,34 @@ Required Properties:
>  		(CMT0 on sh7372, sh73a0 and r8a7740)
>      - "renesas,cmt-32-fast" for the 32-bit CMT with fast clock support
>  		(CMT[234] on sh7372, sh73a0 and r8a7740)
> +    - "renesas,cmt-32-fast-r8a7740" for the R8A7740 32-bit CMT with fast
> +		clock support (CMT[234])
> +    - "renesas,cmt-32-fast-sh7372" for the SH7372 32-bit CMT with fast
> +		clock support (CMT[234])
> +    - "renesas,cmt-32-fast-sh73a0" for the SH73A0 32-bit CMT with fast
> +		clock support (CMT[234])
> +    - "renesas,cmt-32-r8a7740" for the R8a7740 32-bit CMT
> +		(CMT0)
> +    - "renesas,cmt-32-sh7372" for the SH7372 32-bit CMT
> +		(CMT0)
> +    - "renesas,cmt-32-sh73a0" for the SH73a0 32-bit CMT
> +		(CMT0)
>      - "renesas,cmt-48" for the 48-bit CMT
>  		(CMT1 on sh7372, sh73a0 and r8a7740)
>      - "renesas,cmt-48-gen2" for the second generation 48-bit CMT
>  		(CMT[01] on r8a73a4, r8a7790 and r8a7791)
> +    - "renesas,cmt-48-r8a73a4" for the R8A73A4 48-bit CMT
> +		(CMT[01])
> +    - "renesas,cmt-48-r8a7740" for the R8A7740 48-bit CMT
> +		(CMT1)
> +    - "renesas,cmt-48-r8a7790" for the R8A7790 48-bit CMT
> +		(CMT[01])
> +    - "renesas,cmt-48-r8a7791" for the R8A7791 48-bit CMT
> +		(CMT[01])
> +    - "renesas,cmt-48-sh7372" for the SH7372 48-bit CMT
> +		(CMT1)
> +    - "renesas,cmt-48-sh73a0" for the SH73A0 48-bit CMT
> +		(CMT1)
>  
>    - reg: base address and length of the registers block for the timer module.
>    - interrupts: interrupt-specifier for the timer, one per channel.
> @@ -36,7 +60,7 @@ Example: R8A7790 (R-Car H2) CMT0 node
>  	them channels 0 and 1 in the documentation.
>  
>  	cmt0: timer at ffca0000 {
> -		compatible = "renesas,cmt-48-gen2";
> +		compatible = "renesas,cmt-48-r8a7790", "renesas,cmt-48-gen2";
>  		reg = <0 0xffca0000 0 0x1004>;
>  		interrupts = <0 142 IRQ_TYPE_LEVEL_HIGH>,
>  			     <0 142 IRQ_TYPE_LEVEL_HIGH>;
> -- 
> 2.0.1
> 
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