Message-ID: <c2bebcbf9d463d656ae69d489e0e5a88f2540c2e.camel@collabora.com>
Subject: Re: [PATCH v3 1/3] dt-bindings: remoteproc: k3-m4f: Add bindings
 for K3 AM64x SoCs
From:   Martyn Welch <martyn.welch@collabora.com>
To:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Hari Nagalla <hnagalla@ti.com>
Cc:     kernel@collabora.com, linux-remoteproc@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Date:   Tue, 07 Mar 2023 18:26:25 +0000
In-Reply-To: <5c9130de-5092-9446-6e00-d86de7dcd6b4@linaro.org>
References: <20230302171450.1598576-1-martyn.welch@collabora.com>
         <20230302171450.1598576-2-martyn.welch@collabora.com>
         <5c9130de-5092-9446-6e00-d86de7dcd6b4@linaro.org>
Organization: Collabora Ltd.
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
User-Agent: Evolution 3.46.4-1 
MIME-Version: 1.0
Precedence: bulk

On Fri, 2023-03-03 at 09:06 +0100, Krzysztof Kozlowski wrote:
> On 02/03/2023 18:14, Martyn Welch wrote:
>=20
> > +
> > +=C2=A0 mboxes:
> > +=C2=A0=C2=A0=C2=A0 description: |
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 OMAP Mailbox specifier denoting the sub=
-mailbox, to be used
> > for
>=20
> OMAP?
>=20

This device uses a mailbox compatible with the OMAP Mailbox, as defined
in Documentation/devicetree/bindings/mailbox/ti,omap-mailbox.yaml.

I note that documents title reads "TI OMAP2+ and K3 Mailbox devices".
I'll drop the "OMAP" here.

> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 communication with the remote processor=
. This property
> > should match
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 with the sub-mailbox node used in the f=
irmware image.
> > +=C2=A0=C2=A0=C2=A0 maxItems: 1
> > +
> > +=C2=A0 memory-region:
> > +=C2=A0=C2=A0=C2=A0 description: |
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 phandle to the reserved memory nodes to=
 be associated with
> > the
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 remoteproc device. There should be at l=
east two reserved
> > memory nodes
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 defined.=20
>=20
> Don't repeat constraints in free form text.
>=20
> > The reserved memory nodes should be carveout nodes, and
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 should be defined with a "no-map" prope=
rty as per the
> > bindings in
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 Documentation/devicetree/bindings/reser=
ved-memory/reserved-
> > memory.yaml
> > +=C2=A0=C2=A0=C2=A0 minItems: 2
> > +=C2=A0=C2=A0=C2=A0 maxItems: 8
> > +=C2=A0=C2=A0=C2=A0 items:
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 - description: region used for dynamic =
DMA allocations like
> > vrings and
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 vring buffers
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 - description: region reserved for firm=
ware image sections
> > +=C2=A0=C2=A0=C2=A0 additionalItems: true
>=20
> And what is the purpose of the rest of reserved nodes?
>=20

Up to 8 regions can be specified with their purpose determined by the
firmware running on the M4F core. The suggestion (and the
implementation in the example firmware) is to use the first 2 regions
as defined above for remoteproc with the others available to be used
for other purposes if necessary. The address translation module used
can cope with up to 8 regions.

>=20

Martyn