Re: [PATCH v4 2/3] dt-bindings: rng: add bindings for MediaTek ARMv8 SoCs

From: Neal Liu <neal.liu@mediatek.com>
To: Rob Herring <robh@kernel.org>
Cc: "Mark Rutland" <mark.rutland@arm.com>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"Herbert Xu" <herbert@gondor.apana.org.au>,
	wsd_upstream <wsd_upstream@mediatek.com>,
	"Sean Wang" <sean.wang@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"Crystal Guo (郭晶)" <Crystal.Guo@mediatek.com>,
	"linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>,
	"Matt Mackall" <mpm@selenic.com>,
	"Matthias Brugger" <matthias.bgg@gmail.com>,
	"linux-mediatek@lists.infradead.org"
	<linux-mediatek@lists.infradead.org>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>,
	"Neal Liu" <neal.liu@mediatek.com>
Subject: Re: [PATCH v4 2/3] dt-bindings: rng: add bindings for MediaTek ARMv8 SoCs
Date: Wed, 2 Oct 2019 21:47:50 +0800	[thread overview]
Message-ID: <1570024070.4002.1.camel@mtkswgap22> (raw)
In-Reply-To: <1568771054.21700.7.camel@mtkswgap22>

Dear Rob,

Just a gentle ping.

Neal

On Wed, 2019-09-18 at 09:44 +0800, Neal Liu wrote:
> On Tue, 2019-07-23 at 22:35 +0800, Rob Herring wrote:
> > On Mon, Jul 22, 2019 at 8:21 PM Neal Liu <neal.liu@mediatek.com> wrote:
> > >
> > 
> > Please don't top post to lists.
> > 
> > > Dear Rob,
> > >         You can check my driver for detail:
> > >         http://patchwork.kernel.org/patch/11012475/ or patchset 3/3
> > 
> > I could, or you could just answer my question.
> > 
> > >
> > >         This driver is registered as hardware random number generator, and
> > > combines with rng-core.
> > >         We want to add one rng hw based on the dts. Is this proper or do you
> > > have other suggestion to meet this requirement?
> > 
> > It depends. There doesn't appear to be any resource configuration, so
> > why does it need to be in DT. DT is not the only way instantiate
> > drivers.
> > 
> > Rob
> > 
> 
> We would like to consult more about this patch.
> We cannot figure out what method should be used instead of DT.
> The interface to access firmware is "smc" and firmware function only
> exists on certain platforms.
> Some DT has similar way, like:
> http://github.com/torvalds/linux/blob/master/arch/arm64/boot/dts/hisilicon/hi6220-hikey.dts#L470
> 
> 	firmware {
> 		optee {
> 			compatible = "linaro,optee-tz";
> 			method = "smc";
> 		};
> 	};
> 
> Is there any way to instantiate driver on certain platforms without DT?
> Could you give us some examples?
> Thanks
> 
> > >
> > >         Thanks
> > >
> > >
> > > On Tue, 2019-07-23 at 01:13 +0800, Rob Herring wrote:
> > > > On Mon, Jun 24, 2019 at 03:24:11PM +0800, Neal Liu wrote:
> > > > > Document the binding used by the MediaTek ARMv8 SoCs random
> > > > > number generator with TrustZone enabled.
> > > > >
> > > > > Signed-off-by: Neal Liu <neal.liu@mediatek.com>
> > > > > ---
> > > > >  .../devicetree/bindings/rng/mtk-sec-rng.txt        |   10 ++++++++++
> > > > >  1 file changed, 10 insertions(+)
> > > > >  create mode 100644 Documentation/devicetree/bindings/rng/mtk-sec-rng.txt
> > > > >
> > > > > diff --git a/Documentation/devicetree/bindings/rng/mtk-sec-rng.txt b/Documentation/devicetree/bindings/rng/mtk-sec-rng.txt
> > > > > new file mode 100644
> > > > > index 0000000..c04ce15
> > > > > --- /dev/null
> > > > > +++ b/Documentation/devicetree/bindings/rng/mtk-sec-rng.txt
> > > > > @@ -0,0 +1,10 @@
> > > > > +MediaTek random number generator with TrustZone enabled
> > > > > +
> > > > > +Required properties:
> > > > > +- compatible : Should be "mediatek,mtk-sec-rng"
> > > >
> > > > What's the interface to access this?
> > > >
> > > > A node with a 'compatible' and nothing else is a sign of something that
> > > > a parent device should instantiate and doesn't need to be in DT. IOW,
> > > > what do complete bindings for firmware functions look like?
> > > >
> > > > > +
> > > > > +Example:
> > > > > +
> > > > > +hwrng: hwrng {
> > > > > +   compatible = "mediatek,mtk-sec-rng";
> > > > > +}
> > > > > --
> > > > > 1.7.9.5
> > > > >
> > > >
> > > > _______________________________________________
> > > > Linux-mediatek mailing list
> > > > Linux-mediatek@lists.infradead.org
> > > > http://lists.infradead.org/mailman/listinfo/linux-mediatek
> > >
> > >
> 