2017-03-07 14:18:28

by Thomas Petazzoni

[permalink] [raw]
Subject: [PATCH] dt-bindings: rng: clocks property on omap_rng is optional

Commit 52060836f79 ("dt-bindings: omap-rng: Document SafeXcel IP-76
device variant") update the omap_rng Device Tree binding to add support
for the IP-76 variation of the IP. As part of this change, a "clocks"
property was added, but is indicated as "Required", while it is in fact
"Optional": some SoCs do not require a clock for this IP block.

Fixes: 52060836f79 ("dt-bindings: omap-rng: Document SafeXcel IP-76 device variant")
Cc: <[email protected]>
Signed-off-by: Thomas Petazzoni <[email protected]>
---
Documentation/devicetree/bindings/rng/omap_rng.txt | 3 +++
1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/rng/omap_rng.txt b/Documentation/devicetree/bindings/rng/omap_rng.txt
index 4714772..20d435da 100644
--- a/Documentation/devicetree/bindings/rng/omap_rng.txt
+++ b/Documentation/devicetree/bindings/rng/omap_rng.txt
@@ -12,6 +12,9 @@ Required properties:
- reg : Offset and length of the register set for the module
- interrupts : the interrupt number for the RNG module.
Used for "ti,omap4-rng" and "inside-secure,safexcel-eip76"
+
+Optional properties:
+
- clocks: the trng clock source

Example:
--
2.7.4


2017-03-15 17:57:37

by Rob Herring

[permalink] [raw]
Subject: Re: [PATCH] dt-bindings: rng: clocks property on omap_rng is optional

On Tue, Mar 07, 2017 at 03:18:28PM +0100, Thomas Petazzoni wrote:
> Commit 52060836f79 ("dt-bindings: omap-rng: Document SafeXcel IP-76
> device variant") update the omap_rng Device Tree binding to add support
> for the IP-76 variation of the IP. As part of this change, a "clocks"
> property was added, but is indicated as "Required", while it is in fact
> "Optional": some SoCs do not require a clock for this IP block.
>
> Fixes: 52060836f79 ("dt-bindings: omap-rng: Document SafeXcel IP-76 device variant")
> Cc: <[email protected]>
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni-wi1+55ScJUtKEb57/[email protected]>
> ---
> Documentation/devicetree/bindings/rng/omap_rng.txt | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/rng/omap_rng.txt b/Documentation/devicetree/bindings/rng/omap_rng.txt
> index 4714772..20d435da 100644
> --- a/Documentation/devicetree/bindings/rng/omap_rng.txt
> +++ b/Documentation/devicetree/bindings/rng/omap_rng.txt
> @@ -12,6 +12,9 @@ Required properties:
> - reg : Offset and length of the register set for the module
> - interrupts : the interrupt number for the RNG module.
> Used for "ti,omap4-rng" and "inside-secure,safexcel-eip76"
> +
> +Optional properties:
> +

Wouldn't just "for ? compatible only" be more correct?

> - clocks: the trng clock source
>
> Example:
> --
> 2.7.4
>

2017-03-17 12:57:06

by Thomas Petazzoni

[permalink] [raw]
Subject: Re: [PATCH] dt-bindings: rng: clocks property on omap_rng is optional

Hello,

On Wed, 15 Mar 2017 12:57:37 -0500, Rob Herring wrote:

> > diff --git a/Documentation/devicetree/bindings/rng/omap_rng.txt b/Documentation/devicetree/bindings/rng/omap_rng.txt
> > index 4714772..20d435da 100644
> > --- a/Documentation/devicetree/bindings/rng/omap_rng.txt
> > +++ b/Documentation/devicetree/bindings/rng/omap_rng.txt
> > @@ -12,6 +12,9 @@ Required properties:
> > - reg : Offset and length of the register set for the module
> > - interrupts : the interrupt number for the RNG module.
> > Used for "ti,omap4-rng" and "inside-secure,safexcel-eip76"
> > +
> > +Optional properties:
> > +
>
> Wouldn't just "for ? compatible only" be more correct?

I don't know if at the HW point of view the EIP76 will *always* need a
clock. Maybe it depends on the integration in the SoC.

But anyway, let's mark the clocks property as mandatory for
"inside-secure,safexcel-eip76" for the moment, we can always relax this
requirement later on if we realize that some EIP76 have been integrated
in a way that doesn't require a clock.

It is worth mentioning that the actual driver implementation simply
makes the clock optional in all cases, without looking at the
compatible to figure out if the clock must be there or not. But that's
just the current driver implementation. The Device Tree binding
specification can be more specific than what the current driver does.

Therefore: v2 coming.

Best regards,

Thomas
--
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com