RE: [PATCH v4 2/5] media: dt-bindings: media: renesas,drif: Convert to json-schema

[Fabrizio Castro]

Hi Rob,

Thank you for your feedback.

> From: Rob Herring <robh@xxxxxxxxxx>
> Sent: 16 October 2020 16:56
> Subject: Re: [PATCH v4 2/5] media: dt-bindings: media: renesas,drif: Convert to
> json-schema
> 
> On Wed, Oct 14, 2020 at 04:57:16PM +0100, Fabrizio Castro wrote:
> > Convert the Renesas DRIF bindings to DT schema and update
> > MAINTAINERS accordingly.
> >
> > Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@xxxxxxxxxxx>
> > Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> > Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> > ---
> > v3->v4:
> > * Replace "if" statement with "else" statement for the branch
> >   rejecting pinctrl-0 and pinctrl-names properties, as suggested
> >   by Geert
> > v2->v3:
> > * Removed the definition of pinctrl-0 and pinctrl-names, as
> >   suggested by Geert
> > * Added "power-domains" to the list of required properties,
> >   as suggested by Geert
> > v1->v2:
> > * s/controller/Controller/ in the title of renesas,drif.yaml
> >   as suggested by Laurent.
> >
> >  .../bindings/media/renesas,drif.txt           | 177 -----------
> >  .../bindings/media/renesas,drif.yaml          | 277 ++++++++++++++++++
> >  MAINTAINERS                                   |   2 +-
> >  3 files changed, 278 insertions(+), 178 deletions(-)
> >  delete mode 100644
> Documentation/devicetree/bindings/media/renesas,drif.txt
> >  create mode 100644
> Documentation/devicetree/bindings/media/renesas,drif.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/media/renesas,drif.txt
> b/Documentation/devicetree/bindings/media/renesas,drif.txt
> > deleted file mode 100644
> > index 0d8974aa8b38..000000000000
> > --- a/Documentation/devicetree/bindings/media/renesas,drif.txt
> > +++ /dev/null
> > @@ -1,177 +0,0 @@
> > -Renesas R-Car Gen3 Digital Radio Interface controller (DRIF)
> > -------------------------------------------------------------
> > -
> > -R-Car Gen3 DRIF is a SPI like receive only slave device. A general
> > -representation of DRIF interfacing with a master device is shown below.
> > -
> > -+---------------------+                +---------------------+
> > -|                     |-----SCK------->|CLK                  |
> > -|       Master        |-----SS-------->|SYNC  DRIFn (slave)  |
> > -|                     |-----SD0------->|D0                   |
> > -|                     |-----SD1------->|D1                   |
> > -+---------------------+                +---------------------+
> > -
> > -As per datasheet, each DRIF channel (drifn) is made up of two internal
> > -channels (drifn0 & drifn1). These two internal channels share the common
> > -CLK & SYNC. Each internal channel has its own dedicated resources like
> > -irq, dma channels, address space & clock. This internal split is not
> > -visible to the external master device.
> > -
> > -The device tree model represents each internal channel as a separate node.
> > -The internal channels sharing the CLK & SYNC are tied together by their
> > -phandles using a property called "renesas,bonding". For the rest of
> > -the documentation, unless explicitly stated, the word channel implies an
> > -internal channel.
> > -
> > -When both internal channels are enabled they need to be managed together
> > -as one (i.e.) they cannot operate alone as independent devices. Out of the
> > -two, one of them needs to act as a primary device that accepts common
> > -properties of both the internal channels. This channel is identified by a
> > -property called "renesas,primary-bond".
> > -
> > -To summarize,
> > -   - When both the internal channels that are bonded together are enabled,
> > -     the zeroth channel is selected as primary-bond. This channels accepts
> > -     properties common to all the members of the bond.
> > -   - When only one of the bonded channels need to be enabled, the property
> > -     "renesas,bonding" or "renesas,primary-bond" will have no effect. That
> > -     enabled channel can act alone as any other independent device.
> > -
> > -Required properties of an internal channel:
> > --------------------------------------------
> > -- compatible:	"renesas,r8a7795-drif" if DRIF controller is a part of R8A7795
> SoC.
> > -		"renesas,r8a7796-drif" if DRIF controller is a part of R8A7796
> SoC.
> > -		"renesas,rcar-gen3-drif" for a generic R-Car Gen3 compatible
> device.
> > -
> > -		When compatible with the generic version, nodes must list the
> > -		SoC-specific version corresponding to the platform first
> > -		followed by the generic version.
> > -
> > -- reg: offset and length of that channel.
> > -- interrupts: associated with that channel.
> > -- clocks: phandle and clock specifier of that channel.
> > -- clock-names: clock input name string: "fck".
> > -- dmas: phandles to the DMA channels.
> > -- dma-names: names of the DMA channel: "rx".
> > -- renesas,bonding: phandle to the other channel.
> > -
> > -Optional properties of an internal channel:
> > --------------------------------------------
> > -- power-domains: phandle to the respective power domain.
> > -
> > -Required properties of an internal channel when:
> > -	- It is the only enabled channel of the bond (or)
> > -	- If it acts as primary among enabled bonds
> > ---------------------------------------------------------
> > -- pinctrl-0: pin control group to be used for this channel.
> > -- pinctrl-names: must be "default".
> > -- renesas,primary-bond: empty property indicating the channel acts as
> primary
> > -			among the bonded channels.
> > -- port: child port node corresponding to the data input, in accordance with
> > -	the video interface bindings defined in
> > -	Documentation/devicetree/bindings/media/video-interfaces.txt. The
> port
> > -	node must contain at least one endpoint.
> > -
> > -Optional endpoint property:
> > ----------------------------
> > -- sync-active: Indicates sync signal polarity, 0/1 for low/high respectively.
> > -	       This property maps to SYNCAC bit in the hardware manual. The
> > -	       default is 1 (active high).
> > -
> > -Example:
> > ---------
> > -
> > -(1) Both internal channels enabled:
> > ------------------------------------
> > -
> > -When interfacing with a third party tuner device with two data pins as shown
> > -below.
> > -
> > -+---------------------+                +---------------------+
> > -|                     |-----SCK------->|CLK                  |
> > -|       Master        |-----SS-------->|SYNC  DRIFn (slave)  |
> > -|                     |-----SD0------->|D0                   |
> > -|                     |-----SD1------->|D1                   |
> > -+---------------------+                +---------------------+
> > -
> > -	drif00: rif@e6f40000 {
> > -		compatible = "renesas,r8a7795-drif",
> > -			     "renesas,rcar-gen3-drif";
> > -		reg = <0 0xe6f40000 0 0x64>;
> > -		interrupts = <GIC_SPI 12 IRQ_TYPE_LEVEL_HIGH>;
> > -		clocks = <&cpg CPG_MOD 515>;
> > -		clock-names = "fck";
> > -		dmas = <&dmac1 0x20>, <&dmac2 0x20>;
> > -		dma-names = "rx", "rx";
> > -		power-domains = <&sysc R8A7795_PD_ALWAYS_ON>;
> > -		renesas,bonding = <&drif01>;
> > -		renesas,primary-bond;
> > -		pinctrl-0 = <&drif0_pins>;
> > -		pinctrl-names = "default";
> > -		port {
> > -			drif0_ep: endpoint {
> > -			     remote-endpoint = <&tuner_ep>;
> > -			};
> > -		};
> > -	};
> > -
> > -	drif01: rif@e6f50000 {
> > -		compatible = "renesas,r8a7795-drif",
> > -			     "renesas,rcar-gen3-drif";
> > -		reg = <0 0xe6f50000 0 0x64>;
> > -		interrupts = <GIC_SPI 13 IRQ_TYPE_LEVEL_HIGH>;
> > -		clocks = <&cpg CPG_MOD 514>;
> > -		clock-names = "fck";
> > -		dmas = <&dmac1 0x22>, <&dmac2 0x22>;
> > -		dma-names = "rx", "rx";
> > -		power-domains = <&sysc R8A7795_PD_ALWAYS_ON>;
> > -		renesas,bonding = <&drif00>;
> > -	};
> > -
> > -
> > -(2) Internal channel 1 alone is enabled:
> > -----------------------------------------
> > -
> > -When interfacing with a third party tuner device with one data pin as shown
> > -below.
> > -
> > -+---------------------+                +---------------------+
> > -|                     |-----SCK------->|CLK                  |
> > -|       Master        |-----SS-------->|SYNC  DRIFn (slave)  |
> > -|                     |                |D0 (unused)          |
> > -|                     |-----SD-------->|D1                   |
> > -+---------------------+                +---------------------+
> > -
> > -	drif00: rif@e6f40000 {
> > -		compatible = "renesas,r8a7795-drif",
> > -			     "renesas,rcar-gen3-drif";
> > -		reg = <0 0xe6f40000 0 0x64>;
> > -		interrupts = <GIC_SPI 12 IRQ_TYPE_LEVEL_HIGH>;
> > -		clocks = <&cpg CPG_MOD 515>;
> > -		clock-names = "fck";
> > -		dmas = <&dmac1 0x20>, <&dmac2 0x20>;
> > -		dma-names = "rx", "rx";
> > -		power-domains = <&sysc R8A7795_PD_ALWAYS_ON>;
> > -		renesas,bonding = <&drif01>;
> > -	};
> > -
> > -	drif01: rif@e6f50000 {
> > -		compatible = "renesas,r8a7795-drif",
> > -			     "renesas,rcar-gen3-drif";
> > -		reg = <0 0xe6f50000 0 0x64>;
> > -		interrupts = <GIC_SPI 13 IRQ_TYPE_LEVEL_HIGH>;
> > -		clocks = <&cpg CPG_MOD 514>;
> > -		clock-names = "fck";
> > -		dmas = <&dmac1 0x22>, <&dmac2 0x22>;
> > -		dma-names = "rx", "rx";
> > -		power-domains = <&sysc R8A7795_PD_ALWAYS_ON>;
> > -		renesas,bonding = <&drif00>;
> > -		pinctrl-0 = <&drif0_pins>;
> > -		pinctrl-names = "default";
> > -		port {
> > -			drif0_ep: endpoint {
> > -			     remote-endpoint = <&tuner_ep>;
> > -			     sync-active = <0>;
> > -			};
> > -		};
> > -	};
> > diff --git a/Documentation/devicetree/bindings/media/renesas,drif.yaml
> b/Documentation/devicetree/bindings/media/renesas,drif.yaml
> > new file mode 100644
> > index 000000000000..3832ce837553
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/media/renesas,drif.yaml
> > @@ -0,0 +1,277 @@
> > +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/media/renesas,drif.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Renesas R-Car Gen3 Digital Radio Interface Controller (DRIF)
> > +
> > +maintainers:
> > +  - Ramesh Shanmugasundaram <rashanmu@xxxxxxxxx>
> > +  - Fabrizio Castro <fabrizio.castro.jz@xxxxxxxxxxx>
> > +
> > +description: |
> > +  R-Car Gen3 DRIF is a SPI like receive only slave device. A general
> > +  representation of DRIF interfacing with a master device is shown below.
> > +
> > +  +---------------------+                +---------------------+
> > +  |                     |-----SCK------->|CLK                  |
> > +  |       Master        |-----SS-------->|SYNC  DRIFn (slave)  |
> > +  |                     |-----SD0------->|D0                   |
> > +  |                     |-----SD1------->|D1                   |
> > +  +---------------------+                +---------------------+
> > +
> > +  As per datasheet, each DRIF channel (drifn) is made up of two internal
> > +  channels (drifn0 & drifn1). These two internal channels share the common
> > +  CLK & SYNC. Each internal channel has its own dedicated resources like
> > +  irq, dma channels, address space & clock. This internal split is not
> > +  visible to the external master device.
> > +
> > +  The device tree model represents each internal channel as a separate node.
> > +  The internal channels sharing the CLK & SYNC are tied together by their
> > +  phandles using a property called "renesas,bonding". For the rest of
> > +  the documentation, unless explicitly stated, the word channel implies an
> > +  internal channel.
> > +
> > +  When both internal channels are enabled they need to be managed together
> > +  as one (i.e.) they cannot operate alone as independent devices. Out of the
> > +  two, one of them needs to act as a primary device that accepts common
> > +  properties of both the internal channels. This channel is identified by a
> > +  property called "renesas,primary-bond".
> > +
> > +  To summarize,
> > +     * When both the internal channels that are bonded together are enabled,
> > +       the zeroth channel is selected as primary-bond. This channels accepts
> > +       properties common to all the members of the bond.
> > +     * When only one of the bonded channels need to be enabled, the property
> > +       "renesas,bonding" or "renesas,primary-bond" will have no effect. That
> > +       enabled channel can act alone as any other independent device.
> > +
> > +properties:
> > +  compatible:
> > +    items:
> > +      - enum:
> > +        - renesas,r8a7795-drif        # R-Car H3
> > +        - renesas,r8a7796-drif        # R-Car M3-W
> 
> Note the bot error is from yamllint which just got added to the checks.
> Need 2 more spaces indent here.

Thank you for reporting this. Unfortunately I wasn't personally able to reproduce this,
but thankfully a colleague of mine (Prabhakar) was able to reproduce the warning on
his setup. I'll send a v5 to fix this.

Thanks,
Fab

> 
> With that,
> 
> Reviewed-by: Rob Herring <robh@xxxxxxxxxx>