path: root/Documentation/devicetree/bindings/mmc/mmc-controller.yaml

# SPDX-License-Identifier: GPL-2.0
%YAML 1.2
---
$id: http://devicetree.org/schemas/mmc/mmc-controller.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: MMC Controller Generic Binding

maintainers:
  - Ulf Hansson <ulf.hansson@linaro.org>

description: |
  These properties are common to multiple MMC host controllers. Any host
  that requires the respective functionality should implement them using
  these definitions.

  It is possible to assign a fixed index mmcN to an MMC host controller
  (and the corresponding mmcblkN devices) by defining an alias in the
  /aliases device tree node.

properties:
  $nodename:
    pattern: "^mmc(@.*)?$"

  "#address-cells":
    const: 1
    description: |
      The cell is the slot ID if a function subnode is used.

  "#size-cells":
    const: 0

  # Card Detection.
  # If none of these properties are supplied, the host native card
  # detect will be used. Only one of them should be provided.

  broken-cd:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      There is no card detection available; polling must be used.

  cd-gpios:
    maxItems: 1
    description:
      The card detection will be done using the GPIO provided.

  non-removable:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      Non-removable slot (like eMMC); assume always present.

  # *NOTE* on CD and WP polarity. To use common for all SD/MMC host
  # controllers line polarity properties, we have to fix the meaning
  # of the "normal" and "inverted" line levels. We choose to follow
  # the SDHCI standard, which specifies both those lines as "active
  # low." Therefore, using the "cd-inverted" property means, that the
  # CD line is active high, i.e. it is high, when a card is
  # inserted. Similar logic applies to the "wp-inverted" property.
  #
  # CD and WP lines can be implemented on the hardware in one of two
  # ways: as GPIOs, specified in cd-gpios and wp-gpios properties, or
  # as dedicated pins. Polarity of dedicated pins can be specified,
  # using *-inverted properties. GPIO polarity can also be specified
  # using the GPIO_ACTIVE_LOW flag. This creates an ambiguity in the
  # latter case. We choose to use the XOR logic for GPIO CD and WP
  # lines.  This means, the two properties are "superimposed," for
  # example leaving the GPIO_ACTIVE_LOW flag clear and specifying the
  # respective *-inverted property property results in a
  # double-inversion and actually means the "normal" line polarity is
  # in effect.
  wp-inverted:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      The Write Protect line polarity is inverted.

  cd-inverted:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      The CD line polarity is inverted.

  # Other properties

  bus-width:
    description:
      Number of data lines.
    $ref: /schemas/types.yaml#/definitions/uint32
    enum: [1, 4, 8]
    default: 1

  max-frequency:
    description: |
      Maximum operating frequency of the bus:
        - for eMMC, the maximum supported frequency is 200MHz,
        - for SD/SDIO cards the SDR104 mode has a max supported
          frequency of 208MHz,
        - some mmc host controllers do support a max frequency upto
          384MHz.
      So, lets keep the maximum supported value here.

    $ref: /schemas/types.yaml#/definitions/uint32
    minimum: 400000
    maximum: 384000000

  disable-wp:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      When set, no physical write-protect line is present. This
      property should only be specified when the controller has a
      dedicated write-protect detection logic. If a GPIO is always used
      for the write-protect detection logic, it is sufficient to not
      specify the wp-gpios property in the absence of a write-protect
      line. Not used in combination with eMMC or SDIO.

  wp-gpios:
    maxItems: 1
    description:
      GPIO to use for the write-protect detection.

  cd-debounce-delay-ms:
    description:
      Set delay time before detecting card after card insert
      interrupt.

  no-1-8-v:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      When specified, denotes that 1.8V card voltage is not supported
      on this system, even if the controller claims it.

  cap-sd-highspeed:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      SD high-speed timing is supported.

  cap-mmc-highspeed:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      MMC high-speed timing is supported.

  sd-uhs-sdr12:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      SD UHS SDR12 speed is supported.

  sd-uhs-sdr25:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      SD UHS SDR25 speed is supported.

  sd-uhs-sdr50:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      SD UHS SDR50 speed is supported.

  sd-uhs-sdr104:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      SD UHS SDR104 speed is supported.

  sd-uhs-ddr50:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      SD UHS DDR50 speed is supported.

  cap-power-off-card:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      Powering off the card is safe.

  cap-mmc-hw-reset:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      eMMC hardware reset is supported

  cap-sdio-irq:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      enable SDIO IRQ signalling on this interface

  full-pwr-cycle:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      Full power cycle of the card is supported.

  full-pwr-cycle-in-suspend:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      Full power cycle of the card in suspend is supported.

  mmc-ddr-1_2v:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      eMMC high-speed DDR mode (1.2V I/O) is supported.

  mmc-ddr-1_8v:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      eMMC high-speed DDR mode (1.8V I/O) is supported.

  mmc-ddr-3_3v:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      eMMC high-speed DDR mode (3.3V I/O) is supported.

  mmc-hs200-1_2v:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      eMMC HS200 mode (1.2V I/O) is supported.

  mmc-hs200-1_8v:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      eMMC HS200 mode (1.8V I/O) is supported.

  mmc-hs400-1_2v:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      eMMC HS400 mode (1.2V I/O) is supported.

  mmc-hs400-1_8v:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      eMMC HS400 mode (1.8V I/O) is supported.

  mmc-hs400-enhanced-strobe:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      eMMC HS400 enhanced strobe mode is supported

  no-mmc-hs400:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      All eMMC HS400 modes are not supported.

  dsr:
    description:
      Value the card Driver Stage Register (DSR) should be programmed
      with.
    $ref: /schemas/types.yaml#/definitions/uint32
    minimum: 0
    maximum: 0xffff

  no-sdio:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      Controller is limited to send SDIO commands during
      initialization.

  no-sd:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      Controller is limited to send SD commands during initialization.

  no-mmc:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      Controller is limited to send MMC commands during
      initialization.

  fixed-emmc-driver-type:
    description:
      For non-removable eMMC, enforce this driver type. The value is
      the driver type as specified in the eMMC specification (table
      206 in spec version 5.1)
    $ref: /schemas/types.yaml#/definitions/uint32
    minimum: 0
    maximum: 4

  post-power-on-delay-ms:
    description:
      It was invented for MMC pwrseq-simple which could be referred to
      mmc-pwrseq-simple.txt. But now it\'s reused as a tunable delay
      waiting for I/O signalling and card power supply to be stable,
      regardless of whether pwrseq-simple is used. Default to 10ms if
      no available.
    default: 10

  supports-cqe:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      The presence of this property indicates that the corresponding
      MMC host controller supports HW command queue feature.

  disable-cqe-dcmd:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      The presence of this property indicates that the MMC
      controller\'s command queue engine (CQE) does not support direct
      commands (DCMDs).

  keep-power-in-suspend:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      SDIO only. Preserves card power during a suspend/resume cycle.

  wakeup-source:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      SDIO only. Enables wake up of host system on SDIO IRQ assertion.

  vmmc-supply:
    description:
      Supply for the card power

  vqmmc-supply:
    description:
      Supply for the bus IO line power, such as a level shifter.
      If the level shifter is controlled by a GPIO line, this shall
      be modeled as a "regulator-fixed" with a GPIO line for
      switching the level shifter on/off.

  mmc-pwrseq:
    $ref: /schemas/types.yaml#/definitions/phandle
    description:
      System-on-Chip designs may specify a specific MMC power
      sequence. To successfully detect an (e)MMC/SD/SDIO card, that
      power sequence must be maintained while initializing the card.

patternProperties:
  "^.*@[0-9]+$":
    type: object
    description: |
      On embedded systems the cards connected to a host may need
      additional properties. These can be specified in subnodes to the
      host controller node. The subnodes are identified by the
      standard \'reg\' property. Which information exactly can be
      specified depends on the bindings for the SDIO function driver
      for the subnode, as specified by the compatible string.

    properties:
      compatible:
        description: |
          Name of SDIO function following generic names recommended
          practice

      reg:
        items:
          - minimum: 0
            maximum: 7
            description:
              Must contain the SDIO function number of the function this
              subnode describes. A value of 0 denotes the memory SD
              function, values from 1 to 7 denote the SDIO functions.

    required:
      - reg

  "^clk-phase-(legacy|sd-hs|mmc-(hs|hs[24]00|ddr52)|uhs-(sdr(12|25|50|104)|ddr50))$":
    $ref: /schemas/types.yaml#/definitions/uint32-array

    minItems: 2
    maxItems: 2
    items:
      minimum: 0
      maximum: 359
      description:
        Set the clock (phase) delays which are to be configured in the
        controller while switching to particular speed mode. These values
        are in pair of degrees.

dependencies:
  cd-debounce-delay-ms: [ cd-gpios ]
  fixed-emmc-driver-type: [ non-removable ]

additionalProperties: true

examples:
  - |
    mmc3: mmc@1c12000 {
        #address-cells = <1>;
        #size-cells = <0>;
        reg = <0x1c12000 0x200>;
        pinctrl-names = "default";
        pinctrl-0 = <&mmc3_pins_a>;
        vmmc-supply = <&reg_vmmc3>;
        bus-width = <4>;
        non-removable;
        mmc-pwrseq = <&sdhci0_pwrseq>;

        brcmf: wifi@1 {
            reg = <1>;
            compatible = "brcm,bcm4329-fmac";
            interrupt-parent = <&pio>;
            interrupts = <10 8>;
            interrupt-names = "host-wake";
        };
    };