xref: /openbmc/linux/Documentation/devicetree/bindings/bus/qcom,ssc-block-bus.yaml (revision 2aa0d4c8)

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/bus/qcom,ssc-block-bus.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: The AHB Bus Providing a Global View of the SSC Block on (some) qcom SoCs

maintainers:
  - Michael Srba <Michael.Srba@seznam.cz>

description: |
  This binding describes the dependencies (clocks, resets, power domains) which
  need to be turned on in a sequence before communication over the AHB bus
  becomes possible.

  Additionally, the reg property is used to pass to the driver the location of
  two sadly undocumented registers which need to be poked as part of the sequence.

  The SSC (Snapdragon Sensor Core) block contains a gpio controller, i2c/spi/uart
  controllers, a hexagon core, and a clock controller which provides clocks for
  the above.

properties:
  compatible:
    items:
      - const: qcom,msm8998-ssc-block-bus
      - const: qcom,ssc-block-bus

  reg:
    items:
      - description: SSCAON_CONFIG0 registers
      - description: SSCAON_CONFIG1 registers

  reg-names:
    items:
      - const: mpm_sscaon_config0
      - const: mpm_sscaon_config1

  '#address-cells':
    enum: [ 1, 2 ]

  '#size-cells':
    enum: [ 1, 2 ]

  ranges: true

  clocks:
    maxItems: 6

  clock-names:
    items:
      - const: xo
      - const: aggre2
      - const: gcc_im_sleep
      - const: aggre2_north
      - const: ssc_xo
      - const: ssc_ahbs

  power-domains:
    items:
      - description: CX power domain
      - description: MX power domain

  power-domain-names:
    items:
      - const: ssc_cx
      - const: ssc_mx

  resets:
    items:
      - description: Main reset
      - description:
          SSC Branch Control Register reset (associated with the ssc_xo and
          ssc_ahbs clocks)

  reset-names:
    items:
      - const: ssc_reset
      - const: ssc_bcr

  qcom,halt-regs:
    $ref: /schemas/types.yaml#/definitions/phandle-array
    description: describes how to locate the ssc AXI halt register
    items:
      - items:
          - description: Phandle reference to a syscon representing TCSR
          - description: offset for the ssc AXI halt register

required:
  - compatible
  - reg
  - reg-names
  - '#address-cells'
  - '#size-cells'
  - ranges
  - clocks
  - clock-names
  - power-domains
  - power-domain-names
  - resets
  - reset-names
  - qcom,halt-regs

additionalProperties:
  type: object

examples:
  - |
    #include <dt-bindings/clock/qcom,gcc-msm8998.h>
    #include <dt-bindings/clock/qcom,rpmcc.h>
    #include <dt-bindings/power/qcom-rpmpd.h>

    soc {
        #address-cells = <1>;
        #size-cells = <1>;

        // devices under this node are physically located in the SSC block, connected to an ssc-internal bus;
        ssc_ahb_slave: bus@10ac008 {
            #address-cells = <1>;
            #size-cells = <1>;
            ranges;

            compatible = "qcom,msm8998-ssc-block-bus", "qcom,ssc-block-bus";
            reg = <0x10ac008 0x4>, <0x10ac010 0x4>;
            reg-names = "mpm_sscaon_config0", "mpm_sscaon_config1";

            clocks = <&xo>,
                     <&rpmcc RPM_SMD_AGGR2_NOC_CLK>,
                     <&gcc GCC_IM_SLEEP>,
                     <&gcc AGGRE2_SNOC_NORTH_AXI>,
                     <&gcc SSC_XO>,
                     <&gcc SSC_CNOC_AHBS_CLK>;
            clock-names = "xo", "aggre2", "gcc_im_sleep", "aggre2_north", "ssc_xo", "ssc_ahbs";

            resets = <&gcc GCC_SSC_RESET>, <&gcc GCC_SSC_BCR>;
            reset-names = "ssc_reset", "ssc_bcr";

            power-domains = <&rpmpd MSM8998_SSCCX>, <&rpmpd MSM8998_SSCMX>;
            power-domain-names = "ssc_cx", "ssc_mx";

            qcom,halt-regs = <&tcsr_mutex_regs 0x26000>;
        };
    };