Subject: Re: [PATCH v4 01/10] dt-bindings: soc: fsl: cpm_qe: Add TSA controller

From: Rob Herring <[email-masked]>
Date: Mon, 30 Jan 2023 12:27:44 -0600

On Thu, Jan 26, 2023 at 09:32:13AM +0100, Herve Codina wrote:
> Add support for the time slot assigner (TSA)
> available in some PowerQUICC SoC such as MPC885
> or MPC866.
> 
> Signed-off-by: Herve Codina <[email-masked]>
> ---
>  .../bindings/soc/fsl/cpm_qe/fsl,tsa.yaml      | 261 ++++++++++++++++++

fsl,cpm1-tsa.yaml

>  include/dt-bindings/soc/fsl,tsa.h             |  13 +
>  2 files changed, 274 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/soc/fsl/cpm_qe/fsl,tsa.yaml
>  create mode 100644 include/dt-bindings/soc/fsl,tsa.h
> 
> diff --git a/Documentation/devicetree/bindings/soc/fsl/cpm_qe/fsl,tsa.yaml b/Documentation/devicetree/bindings/soc/fsl/cpm_qe/fsl,tsa.yaml
> new file mode 100644
> index 000000000000..d027d4c3cf10
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/soc/fsl/cpm_qe/fsl,tsa.yaml
> @@ -0,0 +1,261 @@
> +# 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 <[email-masked]>
> +
> +description:
> +  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.
> +
> +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
> +
> +  '#serial-cells':

Not a standard property. What's this for? #.*-cells applies to a 
specific pattern of properties.

> +    const: 1
> +
> +patternProperties:
> +  '^tdm@[0-1]$':
> +    description:
> +      The TDM managed by this controller
> +    type: object
> +
> +    additionalProperties: false
> +
> +    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 Tx/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
> +        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:
> +        minItems: 2
> +        items:
> +          - const: l1rsync
> +          - const: l1rclk
> +          - const: l1tsync
> +          - const: l1tclk
> +
> +      fsl,diagnostic-mode:
> +        $ref: /schemas/types.yaml#/definitions/string
> +        enum: [disabled, echo, internal-loopback, control-loopback]

Seems like you would want userspace control of this, not have to make 
firmware changes and reboot to change.

> +        default: disabled
> +        description: |
> +          The diagnostic mode can be used to diagnose some communication issues.
> +          It should not be set (or set to 'disabled') when diagnostic is 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.
> +
> +      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 delay.
> +
> +      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 delay.
> +
> +      fsl,clock-falling-edge:
> +        $ref: /schemas/types.yaml#/definitions/flag
> +        description:
> +          Data is sent on falling edge of the clock (and received on the 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 channel
> +          clock. If 'fsync-rising-edge' is not present, pulses are sampled with
> +          the 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.

tuple

> +            tx_ts_routes =

Not the property name. Put an example in the example(s).

> +               < 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:

You could make these a pattern instead of duplicating the constraints: 

'^fsl,[rt]x-ts-routes$'

> +        $ref: /schemas/types.yaml#/definitions/uint32-matrix
> +        description: |
> +          A list of tupple that indicates the Rx time-slots routes.
> +            tx_ts_routes =
> +               < 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:
> +              maxItems: 2
> +            clock-names:
> +              maxItems: 2
> +        else:
> +          properties:
> +            clocks:
> +              minItems: 4
> +            clock-names:
> +              minItems: 4
> +
> +    required:
> +      - reg
> +      - clocks
> +      - clock-names
> +
> +required:
> +  - compatible
> +  - reg
> +  - reg-names
> +  - '#address-cells'
> +  - '#size-cells'
> +  - '#serial-cells'
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/soc/fsl,tsa.h>
> +
> +    tsa@ae0 {
> +        compatible = "fsl,mpc885-tsa", "fsl,cpm1-tsa";
> +        reg = <0xae0 0x10>,
> +              <0xc00 0x200>;
> +        reg-names = "si_regs", "si_ram";
> +
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +        #serial-cells = <1>;
> +
> +        tdm@0 {
> +            /* TDMa */
> +            reg = <0>;
> +
> +            clocks = <&clk_l1rsynca>, <&clk_l1rclka>;
> +            clock-names = "l1rsync", "l1rclk";
> +
> +            fsl,common-rxtx-pins;
> +            fsl,fsync-rising-edge;
> +
> +            fsl,tx-ts-routes = < 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 = < 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/soc/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
> -- 
> 2.39.0
>