Re: [PATCH v2 1/7] dt-bindings: soc: ti: Add TI PRUSS bindings

[Suman Anna <s-anna@ti.com>]

Hi Rob,

On 8/21/20 9:42 AM, Grzegorz Jaszczyk wrote:
> This patch adds the bindings for the Programmable Real-Time Unit
> and Industrial Communication Subsystem (PRU-ICSS) present on various
> TI SoCs. The IP is present on multiple TI SoC architecture families
> including the OMAP architecture SoCs such as AM33xx, AM437x and
> AM57xx; and on a Keystone 2 architecture based 66AK2G SoC. It is
> also present on the Davinci based OMAPL138 SoCs and K3 architecture
> based AM65x and J721E SoCs as well.
> 
> The IP has a number of sub-modules some of which are represented as
> their own devices. This binding covers only the top-level sub-system
> devices, and some sub-modules like MDIO, MII_RT (Ethernet MII_RT module
> with MII ports) and IEP (Industrial Ethernet Peripheral). The remaining
> sub-modules bindings shall be defined in the respective driver
> subsystem bindings folders. Couple of full examples have also been
> added demonstrating the devices on AM335x and AM437x SoCs.
> 
> Signed-off-by: Suman Anna <s-anna@ti.com>
> Signed-off-by: Roger Quadros <rogerq@ti.com>
> Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
> ---
> v1-v2 (requested by Rob):
> - Add unit address pattern for all sub-nodes.
> - Add "additionalProperties: false" to all sub-nodes and entire
>   description. This allow to catch and fix some issues like missing
>   "#address-cells" property description.
> - Drop ranges description.
> - Fix compatible name in example binding for AM43xx.
> - Drop the *.yaml references from description as they are not merged yet
>   and therefore they can't be converted to $ref.
> - Drop reviewed-by tag due to introduced changes.

Any comments on this fixed up version, Greg has addressed all your comments?

Also appreciate it if you can review an add-on patch on this very same binding
while at this,
https://patchwork.ozlabs.org/project/devicetree-bindings/patch/1599158501-8302-2-git-send-email-grzegorz.jaszczyk@linaro.org/

regards
Suman

> ---
>  .../devicetree/bindings/soc/ti/ti,pruss.yaml       | 320 +++++++++++++++++++++
>  1 file changed, 320 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/soc/ti/ti,pruss.yaml
> 
> diff --git a/Documentation/devicetree/bindings/soc/ti/ti,pruss.yaml b/Documentation/devicetree/bindings/soc/ti/ti,pruss.yaml
> new file mode 100644
> index 0000000..a13e4df
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/soc/ti/ti,pruss.yaml
> @@ -0,0 +1,320 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/soc/ti/ti,pruss.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: |+
> +  TI Programmable Real-Time Unit and Industrial Communication Subsystem
> +
> +maintainers:
> +  - Suman Anna <s-anna@ti.com>
> +
> +description: |+
> +
> +  The Programmable Real-Time Unit and Industrial Communication Subsystem
> +  (PRU-ICSS a.k.a. PRUSS) is present on various TI SoCs such as AM335x, AM437x,
> +  Keystone 66AK2G, OMAP-L138/DA850 etc. A PRUSS consists of dual 32-bit RISC
> +  cores (Programmable Real-Time Units, or PRUs), shared RAM, data and
> +  instruction RAMs, some internal peripheral modules to facilitate industrial
> +  communication, and an interrupt controller.
> +
> +  The programmable nature of the PRUs provide flexibility to implement custom
> +  peripheral interfaces, fast real-time responses, or specialized data handling.
> +  The common peripheral modules include the following,
> +    - an Ethernet MII_RT module with two MII ports
> +    - an MDIO port to control external Ethernet PHYs
> +    - an Industrial Ethernet Peripheral (IEP) to manage/generate Industrial
> +      Ethernet functions
> +    - an Enhanced Capture Module (eCAP)
> +    - an Industrial Ethernet Timer with 7/9 capture and 16 compare events
> +    - a 16550-compatible UART to support PROFIBUS
> +    - Enhanced GPIO with async capture and serial support
> +
> +  A PRU-ICSS subsystem can have up to three shared data memories. A PRU core
> +  acts on a primary Data RAM (there are usually 2 Data RAMs) at its address
> +  0x0, but also has access to a secondary Data RAM (primary to the other PRU
> +  core) at its address 0x2000. A shared Data RAM, if present, can be accessed
> +  by both the PRU cores. The Interrupt Controller (INTC) and a CFG module are
> +  common to both the PRU cores. Each PRU core also has a private instruction
> +  RAM, and specific register spaces for Control and Debug functionalities.
> +
> +  Various sub-modules within a PRU-ICSS subsystem are represented as individual
> +  nodes and are defined using a parent-child hierarchy depending on their
> +  integration within the IP and the SoC. These nodes are described in the
> +  following sections.
> +
> +
> +  PRU-ICSS Node
> +  ==============
> +  Each PRU-ICSS instance is represented as its own node with the individual PRU
> +  processor cores, the memories node, an INTC node and an MDIO node represented
> +  as child nodes within this PRUSS node. This node shall be a child of the
> +  corresponding interconnect bus nodes or target-module nodes.
> +
> +  See ../../mfd/syscon.yaml for generic SysCon binding details.
> +
> +
> +properties:
> +  $nodename:
> +    pattern: "^(pruss|icssg)@[0-9a-f]+$"
> +
> +  compatible:
> +    enum:
> +      - ti,am3356-pruss  # for AM335x SoC family
> +      - ti,am4376-pruss0 # for AM437x SoC family and PRUSS unit 0
> +      - ti,am4376-pruss1 # for AM437x SoC family and PRUSS unit 1
> +      - ti,am5728-pruss  # for AM57xx SoC family
> +      - ti,k2g-pruss     # for 66AK2G SoC family
> +      - ti,am654-icssg   # for K3 AM65x SoC family
> +      - ti,j721e-icssg   # for K3 J721E SoC family
> +
> +  reg:
> +    maxItems: 1
> +
> +  "#address-cells":
> +    const: 1
> +
> +  "#size-cells":
> +    const: 1
> +
> +  ranges:
> +    maxItems: 1
> +
> +  power-domains:
> +    description: |
> +      This property is as per sci-pm-domain.txt.
> +
> +patternProperties:
> +
> +  memories@[a-f0-9]+$:
> +    description: |
> +      The various Data RAMs within a single PRU-ICSS unit are represented as a
> +      single node with the name 'memories'.
> +
> +    type: object
> +
> +    properties:
> +      reg:
> +        minItems: 2 # On AM437x one of two PRUSS units don't contain Shared RAM.
> +        maxItems: 3
> +        items:
> +          - description: Address and size of the Data RAM0.
> +          - description: Address and size of the Data RAM1.
> +          - description: |
> +              Address and size of the Shared Data RAM. Note that on AM437x one
> +              of two PRUSS units don't contain Shared RAM, while the second one
> +              has it.
> +
> +      reg-names:
> +        minItems: 2
> +        maxItems: 3
> +        items:
> +          - const: dram0
> +          - const: dram1
> +          - const: shrdram2
> +
> +    required:
> +      - reg
> +      - reg-names
> +
> +    additionalProperties: false
> +
> +  cfg@[a-f0-9]+$:
> +    description: |
> +      PRU-ICSS configuration space. CFG sub-module represented as a SysCon.
> +
> +    type: object
> +
> +    properties:
> +      compatible:
> +        items:
> +          - const: ti,pruss-cfg
> +          - const: syscon
> +
> +      reg:
> +        maxItems: 1
> +
> +    additionalProperties: false
> +
> +  iep@[a-f0-9]+$:
> +    description: |
> +      Industrial Ethernet Peripheral to manage/generate Industrial Ethernet
> +      functions such as time stamping. Each PRUSS has either 1 IEP (on AM335x,
> +      AM437x, AM57xx & 66AK2G SoCs) or 2 IEPs (on K3 AM65x & J721E SoCs ). IEP
> +      is used for creating PTP clocks and generating PPS signals.
> +
> +    type: object
> +
> +  mii-rt@[a-f0-9]+$:
> +    description: |
> +      Real-Time Ethernet to support multiple industrial communication protocols.
> +      MII-RT sub-module represented as a SysCon.
> +
> +    type: object
> +
> +    properties:
> +      compatible:
> +        items:
> +          - const: ti,pruss-mii
> +          - const: syscon
> +
> +      reg:
> +        maxItems: 1
> +
> +    additionalProperties: false
> +
> +  mii-g-rt@[a-f0-9]+$:
> +    description: |
> +      The Real-time Media Independent Interface to support multiple industrial
> +      communication protocols (G stands for Gigabit). MII-G-RT sub-module
> +      represented as a SysCon.
> +
> +    type: object
> +
> +    properties:
> +      compatible:
> +        items:
> +          - const: ti,pruss-mii-g
> +          - const: syscon
> +
> +      reg:
> +        maxItems: 1
> +
> +    additionalProperties: false
> +
> +  interrupt-controller@[a-f0-9]+$:
> +    description: |
> +      PRUSS INTC Node. Each PRUSS has a single interrupt controller instance
> +      that is common to all the PRU cores. This should be represented as an
> +      interrupt-controller node.
> +
> +    type: object
> +
> +  mdio@[a-f0-9]+$:
> +    description: |
> +      MDIO Node. Each PRUSS has an MDIO module that can be used to control
> +      external PHYs. The MDIO module used within the PRU-ICSS is an instance of
> +      the MDIO Controller used in TI Davinci SoCs.
> +
> +    allOf:
> +      - $ref: /schemas/net/ti,davinci-mdio.yaml#
> +
> +    type: object
> +
> +  "^(pru|rtu|txpru)@[0-9a-f]+$":
> +    description: |
> +      PRU Node. Each PRUSS has dual PRU cores, each represented as a RemoteProc
> +      device through a PRU child node each. Each node can optionally be rendered
> +      inactive by using the standard DT string property, "status". The ICSSG IP
> +      present on K3 SoCs have additional auxiliary PRU cores with slightly
> +      different IP integration.
> +
> +    type: object
> +
> +required:
> +  - compatible
> +  - reg
> +  - ranges
> +
> +additionalProperties: false
> +
> +# Due to inability of correctly verifying sub-nodes with an @address through
> +# the "required" list, the required sub-nodes below are commented out for now.
> +
> +#required:
> +# - memories
> +# - interrupt-controller
> +# - pru
> +
> +if:
> +  properties:
> +    compatible:
> +      contains:
> +        enum:
> +          - ti,k2g-pruss
> +          - ti,am654-icssg
> +          - ti,j721e-icssg
> +then:
> +  required:
> +    - power-domains
> +
> +examples:
> +  - |
> +
> +    /* Example 1 AM33xx PRU-ICSS */
> +    pruss: pruss@0 {
> +        compatible = "ti,am3356-pruss";
> +        reg = <0x0 0x80000>;
> +        #address-cells = <1>;
> +        #size-cells = <1>;
> +        ranges;
> +
> +        pruss_mem: memories@0 {
> +            reg = <0x0 0x2000>,
> +                  <0x2000 0x2000>,
> +                  <0x10000 0x3000>;
> +            reg-names = "dram0", "dram1", "shrdram2";
> +        };
> +
> +        pruss_cfg: cfg@26000 {
> +            compatible = "ti,pruss-cfg", "syscon";
> +            reg = <0x26000 0x2000>;
> +        };
> +
> +        pruss_mii_rt: mii-rt@32000 {
> +            compatible = "ti,pruss-mii", "syscon";
> +            reg = <0x32000 0x58>;
> +        };
> +
> +        pruss_mdio: mdio@32400 {
> +            compatible = "ti,davinci_mdio";
> +            reg = <0x32400 0x90>;
> +            clocks = <&dpll_core_m4_ck>;
> +            clock-names = "fck";
> +            bus_freq = <1000000>;
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +        };
> +    };
> +
> +  - |
> +
> +    /* Example 2 AM43xx PRU-ICSS with PRUSS1 node */
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    pruss1: pruss@0 {
> +        compatible = "ti,am4376-pruss1";
> +        reg = <0x0 0x40000>;
> +        #address-cells = <1>;
> +        #size-cells = <1>;
> +        ranges;
> +
> +        pruss1_mem: memories@0 {
> +            reg = <0x0 0x2000>,
> +                  <0x2000 0x2000>,
> +                  <0x10000 0x8000>;
> +            reg-names = "dram0", "dram1", "shrdram2";
> +        };
> +
> +        pruss1_cfg: cfg@26000 {
> +            compatible = "ti,pruss-cfg", "syscon";
> +            reg = <0x26000 0x2000>;
> +        };
> +
> +        pruss1_mii_rt: mii-rt@32000 {
> +            compatible = "ti,pruss-mii", "syscon";
> +            reg = <0x32000 0x58>;
> +        };
> +
> +        pruss1_mdio: mdio@32400 {
> +            compatible = "ti,davinci_mdio";
> +            reg = <0x32400 0x90>;
> +            clocks = <&dpll_core_m4_ck>;
> +            clock-names = "fck";
> +            bus_freq = <1000000>;
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +        };
> +    };
> +
> +...
>