Date:   Mon, 23 Jan 2023 12:36:49 +0100
From:   Herve Codina <herve.codina@bootlin.com>
To:     Rob Herring <robh@kernel.org>
Cc:     Li Yang <leoyang.li@nxp.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        Christophe Leroy <christophe.leroy@csgroup.eu>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Nicholas Piggin <npiggin@gmail.com>,
        Qiang Zhao <qiang.zhao@nxp.com>,
        Jaroslav Kysela <perex@perex.cz>,
        Takashi Iwai <tiwai@suse.com>,
        Shengjiu Wang <shengjiu.wang@gmail.com>,
        Xiubo Li <Xiubo.Lee@gmail.com>,
        Fabio Estevam <festevam@gmail.com>,
        Nicolin Chen <nicoleotsuka@gmail.com>,
        linuxppc-dev@lists.ozlabs.org,
        linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, alsa-devel@alsa-project.org,
        Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Subject: Re: [PATCH v3 01/10] dt-bindings: soc: fsl: cpm_qe: Add TSA
 controller
Message-ID: <20230123123649.63f17dad@bootlin.com>
In-Reply-To: <20230117145529.GA3044055-robh@kernel.org>
References: <20230113103759.327698-1-herve.codina@bootlin.com>
        <20230113103759.327698-2-herve.codina@bootlin.com>
        <20230117145529.GA3044055-robh@kernel.org>
Organization: Bootlin
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

Hi Rob,

On Tue, 17 Jan 2023 08:55:29 -0600
Rob Herring <robh@kernel.org> wrote:

> On Fri, Jan 13, 2023 at 11:37:50AM +0100, Herve Codina wrote:
> > Add support for the time slot assigner (TSA)
> > available in some PowerQUICC SoC such as MPC885
> > or MPC866. =20
>=20
> An odd line wrap length...=20

Will be changed in v4.

>=20
> >=20
> > Signed-off-by: Herve Codina <herve.codina@bootlin.com>
> > ---
> >  .../bindings/soc/fsl/cpm_qe/fsl,tsa.yaml      | 260 ++++++++++++++++++
> >  include/dt-bindings/soc/fsl,tsa.h             |  13 +
> >  2 files changed, 273 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/soc/fsl/cpm_qe/fs=
l,tsa.yaml
> >  create mode 100644 include/dt-bindings/soc/fsl,tsa.h
> >=20
> > diff --git a/Documentation/devicetree/bindings/soc/fsl/cpm_qe/fsl,tsa.y=
aml b/Documentation/devicetree/bindings/soc/fsl/cpm_qe/fsl,tsa.yaml
> > new file mode 100644
> > index 000000000000..eb17b6119abd
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/soc/fsl/cpm_qe/fsl,tsa.yaml
> > @@ -0,0 +1,260 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/soc/fsl/cpm_qe/fsl,tsa.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: PowerQUICC CPM Time-slot assigner (TSA) controller
> > +
> > +maintainers:
> > +  - Herve Codina <herve.codina@bootlin.com>
> > +
> > +description: | =20
>=20
> Don't need '|' if no formatting.

Will be changed in v4.

>=20
> > +  The TSA is the time-slot assigner that can be found on some
> > +  PowerQUICC SoC.
> > +  Its purpose is to route some TDM time-slots to other internal
> > +  serial controllers. =20
>=20
> Wrap at 80.

Will be fixed in v4.

>=20
> > +
> > +properties:
> > +  compatible:
> > +    items:
> > +      - enum:
> > +          - fsl,mpc885-tsa
> > +          - fsl,mpc866-tsa
> > +      - const: fsl,cpm1-tsa
> > +
> > +  reg:
> > +    items:
> > +      - description: SI (Serial Interface) register base
> > +      - description: SI RAM base
> > +
> > +  reg-names:
> > +    items:
> > +      - const: si_regs
> > +      - const: si_ram
> > +
> > +  '#address-cells':
> > +    const: 1
> > +
> > +  '#size-cells':
> > +    const: 0
> > +
> > +patternProperties:
> > +  '^tdm@[0-1]$':
> > +    description:
> > +      The TDM managed by this controller
> > +    type: object =20
>=20
>        additionalProperties: false

Will be added in v4.

>=20
> > +
> > +    properties:
> > +      reg:
> > +        minimum: 0
> > +        maximum: 1
> > +        description:
> > +          The TDM number for this TDM, 0 for TDMa and 1 for TDMb
> > +
> > +      fsl,common-rxtx-pins:
> > +        $ref: /schemas/types.yaml#/definitions/flag
> > +        description:
> > +          The hardware can use four dedicated pins for Tx clock,
> > +          Tx sync, Rx clock and Rx sync or use only two pins,
> > +          Tx/Rx clock and Rx/Rx sync.
> > +          Without the 'fsl,common-rxtx-pins' property, the four
> > +          pins are used. With the 'fsl,common-rxtx-pins' property,
> > +          two pins are used.
> > +
> > +      clocks:
> > +        minItems: 2
> > +        maxItems: 4
> > +
> > +      clock-names:
> > +        minItems: 2
> > +        maxItems: 4
> > +
> > +      fsl,mode: =20
>=20
> 'mode' is a bit vague. It's already used as well which can be a problem=20
> if there are differing types. (There's not in this case)

What do you think about:
      fsl,diagnostic-mode:
        $ref: /schemas/types.yaml#/definitions/string
        enum: [disabled, echo, internal-loopback, control-loopback]
        default: disabled
        description: |
          The diagnostic mode can be used to diagnose some communication is=
sues.
          It should not be present (or set to 'disabled') when diagnostic i=
s not
          needed.
          Diagnostic mode:
            - disabled:
                Diagnostic disabled (ie. normal operation)
            - echo:
                Automatic echo. Rx data is resent on Tx
            - internal-loopback:
                The TDM transmitter is connected to the receiver.
                Data appears on Tx pin.
            - control-loopback:
                The TDM transmitter is connected to the receiver.
                The Tx pin is disconnected.

>=20
> > +        $ref: /schemas/types.yaml#/definitions/string
> > +        enum: [normal, echo, internal-loopback, control-loopback]
> > +        default: normal
> > +        description: |
> > +          Operational mode:
> > +            - normal:
> > +                Normal operation
> > +            - echo:
> > +                Automatic echo. Rx data is resent on Tx
> > +            - internal-loopback:
> > +                The TDM transmitter is connected to the receiver.
> > +                Data appears on Tx pin.
> > +            - control-loopback:
> > +                The TDM transmitter is connected to the receiver.
> > +                The Tx pin is disconnected.
> > +
> > +      fsl,rx-frame-sync-delay-bits:
> > +        enum: [0, 1, 2, 3]
> > +        default: 0
> > +        description: |
> > +          Receive frame sync delay in number of bits.
> > +          Indicates the delay between the Rx sync and the first bit of=
 the
> > +          Rx frame. 0 for no bit delay. 1, 2 or 3 for 1, 2 or 3 bits d=
elay.
> > +
> > +      fsl,tx-frame-sync-delay-bits:
> > +        enum: [0, 1, 2, 3]
> > +        default: 0
> > +        description: |
> > +          Transmit frame sync delay in number of bits.
> > +          Indicates the delay between the Tx sync and the first bit of=
 the
> > +          Tx frame. 0 for no bit delay. 1, 2 or 3 for 1, 2 or 3 bits d=
elay.
> > +
> > +      fsl,clock-falling-edge:
> > +        $ref: /schemas/types.yaml#/definitions/flag
> > +        description: |
> > +          Data is sent on falling edge of the clock (and received on t=
he
> > +          rising edge).
> > +          If 'clock-falling-edge' is not present, data is sent on the
> > +          rising edge (and received on the falling edge).
> > +
> > +      fsl,fsync-rising-edge:
> > +        $ref: /schemas/types.yaml#/definitions/flag
> > +        description:
> > +          Frame sync pulses are sampled with the rising edge of the ch=
annel
> > +          clock. If 'fsync-rising-edge' is not present, pulses are sam=
ple
> > +          with e falling edge.
> > +
> > +      fsl,double-speed-clock:
> > +        $ref: /schemas/types.yaml#/definitions/flag
> > +        description:
> > +          The channel clock is twice the data rate.
> > +
> > +      fsl,tx-ts-routes:
> > +        $ref: /schemas/types.yaml#/definitions/uint32-matrix
> > +        description: |
> > +          A list of tupple that indicates the Tx time-slots routes.
> > +            tx_ts_routes =3D
> > +               < 2 0 >, /* The first 2 time slots are not used */
> > +               < 3 1 >, /* The next 3 ones are route to SCC2 */
> > +               < 4 0 >, /* The next 4 ones are not used */
> > +               < 2 2 >; /* The nest 2 ones are route to SCC3 */
> > +        items:
> > +          items:
> > +            - description:
> > +                The number of time-slots
> > +              minimum: 1
> > +              maximum: 64
> > +            - description: |
> > +                The source serial interface (dt-bindings/soc/fsl,tsa.h
> > +                defines these values)
> > +                 - 0: No destination
> > +                 - 1: SCC2
> > +                 - 2: SCC3
> > +                 - 3: SCC4
> > +                 - 4: SMC1
> > +                 - 5: SMC2
> > +              enum: [0, 1, 2, 3, 4, 5]
> > +        minItems: 1
> > +        maxItems: 64
> > +
> > +      fsl,rx-ts-routes:
> > +        $ref: /schemas/types.yaml#/definitions/uint32-matrix
> > +        description: |
> > +          A list of tupple that indicates the Rx time-slots routes.
> > +            tx_ts_routes =3D
> > +               < 2 0 >, /* The first 2 time slots are not used */
> > +               < 3 1 >, /* The next 3 ones are route from SCC2 */
> > +               < 4 0 >, /* The next 4 ones are not used */
> > +               < 2 2 >; /* The nest 2 ones are route from SCC3 */
> > +        items:
> > +          items:
> > +            - description:
> > +                The number of time-slots
> > +              minimum: 1
> > +              maximum: 64
> > +            - description: |
> > +                The destination serial interface (dt-bindings/soc/fsl,=
tsa.h
> > +                defines these values)
> > +                 - 0: No destination
> > +                 - 1: SCC2
> > +                 - 2: SCC3
> > +                 - 3: SCC4
> > +                 - 4: SMC1
> > +                 - 5: SMC2
> > +              enum: [0, 1, 2, 3, 4, 5]
> > +        minItems: 1
> > +        maxItems: 64
> > +
> > +    allOf:
> > +      # If fsl,common-rxtx-pins is present, only 2 clocks are needed.
> > +      # Else, the 4 clocks must be present.
> > +      - if:
> > +          required:
> > +            - fsl,common-rxtx-pins
> > +        then:
> > +          properties:
> > +            clocks:
> > +              items:
> > +                - description: External clock connected to L1RSYNC pin
> > +                - description: External clock connected to L1RCLK pin
> > +            clock-names:
> > +              items:
> > +                - const: l1rsync
> > +                - const: l1rclk
> > +        else:
> > +          properties:
> > +            clocks:
> > +              items:
> > +                - description: External clock connected to L1RSYNC pin
> > +                - description: External clock connected to L1RCLK pin
> > +                - description: External clock connected to L1TSYNC pin
> > +                - description: External clock connected to L1TCLK pin
> > +            clock-names:
> > +              items:
> > +                - const: l1rsync
> > +                - const: l1rclk
> > +                - const: l1tsync
> > +                - const: l1tclk =20
>=20
> As the names are the same, just the length varies between 2 or 4, move=20
> all this to the main definition and here just put constraints on the=20
> length.

Ok, will be done in v4.

>=20
> > +
> > +    required:
> > +      - reg
> > +      - clocks
> > +      - clock-names
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - reg-names
> > +  - '#address-cells'
> > +  - '#size-cells'
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/soc/fsl,tsa.h>
> > +
> > +    tsa@ae0 {
> > +        compatible =3D "fsl,mpc885-tsa", "fsl,cpm1-tsa";
> > +        reg =3D <0xae0 0x10>,
> > +              <0xc00 0x200>;
> > +        reg-names =3D "si_regs", "si_ram";
> > +
> > +        #address-cells =3D <1>;
> > +        #size-cells =3D <0>;
> > +
> > +        tdm@0 {
> > +            /* TDMa */
> > +            reg =3D <0>;
> > +
> > +            clocks =3D <&clk_l1rsynca>, <&clk_l1rclka>;
> > +            clock-names =3D "l1rsync", "l1rclk";
> > +
> > +            fsl,common-rxtx-pins;
> > +            fsl,fsync-rising-edge;
> > +
> > +            fsl,tx-ts-routes =3D < 2 0 >,             /* TS 0..1 */
> > +                           < 24 FSL_CPM_TSA_SCC4 >, /* TS 2..25 */
> > +                           < 1 0 >,                 /* TS 26 */
> > +                           < 5 FSL_CPM_TSA_SCC3 >;  /* TS 27..31 */
> > +
> > +            fsl,rx-ts-routes =3D < 2 0 >,             /* TS 0..1 */
> > +                           < 24 FSL_CPM_TSA_SCC4 >, /* 2..25 */
> > +                           < 1 0 >,                 /* TS 26 */
> > +                           < 5 FSL_CPM_TSA_SCC3 >;  /* TS 27..31 */
> > +        };
> > +    };
> > diff --git a/include/dt-bindings/soc/fsl,tsa.h b/include/dt-bindings/so=
c/fsl,tsa.h
> > new file mode 100644
> > index 000000000000..2cc44e867dbe
> > --- /dev/null
> > +++ b/include/dt-bindings/soc/fsl,tsa.h
> > @@ -0,0 +1,13 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause */
> > +
> > +#ifndef __DT_BINDINGS_SOC_FSL_TSA_H
> > +#define __DT_BINDINGS_SOC_FSL_TSA_H
> > +
> > +#define FSL_CPM_TSA_NU		0	/* Pseuso Cell Id for not used item */
> > +#define FSL_CPM_TSA_SCC2	1
> > +#define FSL_CPM_TSA_SCC3	2
> > +#define FSL_CPM_TSA_SCC4	3
> > +#define FSL_CPM_TSA_SMC1	4
> > +#define FSL_CPM_TSA_SMC2	5
> > +
> > +#endif
> > --=20
> > 2.38.1
> >  =20

Thanks for the review,

Herv=C3=A9
--=20
Herv=C3=A9 Codina, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com