Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml

# SPDX-License-Identifier: GPL-2.0-only
%YAML 1.2
---
$id: http://devicetree.org/schemas/mtd/jedec,spi-nor.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: SPI NOR flash ST M25Pxx (and similar) serial flash chips

maintainers:
  - Rob Herring <robh@kernel.org>

allOf:
  - $ref: mtd.yaml#
  - $ref: /schemas/spi/spi-peripheral-props.yaml#

properties:
  compatible:
    oneOf:
      - items:
          - pattern: "^((((micron|spansion|st),)?\
              (m25p(40|80|16|32|64|128)|\
              n25q(32b|064|128a11|128a13|256a|512a|164k)))|\
              atmel,at25df(321a|641|081a)|\
              everspin,mr25h(10|40|128|256)|\
              (mxicy|macronix),mx25l(4005a|1606e|6405d|8005|12805d|25635e)|\
              (mxicy|macronix),mx25u(4033|4035)|\
              (spansion,)?s25fl(128s|256s1|512s|008k|064k|164k)|\
              (sst|microchip),sst25vf(016b|032b|040b)|\
              (sst,)?sst26wf016b|\
              (sst,)?sst25wf(040b|080)|\
              winbond,w25x(80|32)|\
              (winbond,)?w25q(16|32(w|dw)?|64(dw)?|80bl|128(fw)?|256))$"
          - const: jedec,spi-nor
      - items:
          - enum:
              - issi,is25lp016d
              - micron,mt25qu02g
              - mxicy,mx25r1635f
              - mxicy,mx25u6435f
              - mxicy,mx25v8035f
              - spansion,s25sl12801
              - spansion,s25fs512s
          - const: jedec,spi-nor
      - const: jedec,spi-nor
    description:
      SPI NOR flashes compatible with the JEDEC SFDP standard or which may be
      identified with the READ ID opcode (0x9F) do not deserve a specific
      compatible. They should instead only be matched against the generic
      "jedec,spi-nor" compatible.

  reg:
    minItems: 1
    maxItems: 2

  m25p,fast-read:
    type: boolean
    description:
      Use the "fast read" opcode to read data from the chip instead of the usual
      "read" opcode. This opcode is not supported by all chips and support for
      it can not be detected at runtime. Refer to your chips' datasheet to check
      if this is supported by your chip.

  broken-flash-reset:
    type: boolean
    description:
      Some flash devices utilize stateful addressing modes (e.g., for 32-bit
      addressing) which need to be managed carefully by a system. Because these
      sorts of flash don't have a standardized software reset command, and
      because some systems don't toggle the flash RESET# pin upon system reset
      (if the pin even exists at all), there are systems which cannot reboot
      properly if the flash is left in the "wrong" state. This boolean flag can
      be used on such systems, to denote the absence of a reliable reset
      mechanism.

  no-wp:
    type: boolean
    description:
      The status register write disable (SRWD) bit in status register, combined
      with the WP# signal, provides hardware data protection for the device. When
      the SRWD bit is set to 1, and the WP# signal is either driven LOW or hard
      strapped to LOW, the status register nonvolatile bits become read-only and
      the WRITE STATUS REGISTER operation will not execute. The only way to exit
      this hardware-protected mode is to drive WP# HIGH. If the WP# signal of the
      flash device is not connected or is wrongly tied to GND (that includes internal
      pull-downs) then status register permanently becomes read-only as the SRWD bit
      cannot be reset. This boolean flag can be used on such systems to avoid setting
      the SRWD bit while writing the status register. WP# signal hard strapped to GND
      can be a valid use case.

  reset-gpios:
    description:
      A GPIO line connected to the RESET (active low) signal of the device.
      If "broken-flash-reset" is present then having this property does not
      make any difference.

  spi-cpol: true
  spi-cpha: true

dependencies:
  spi-cpol: [ spi-cpha ]
  spi-cpha: [ spi-cpol ]

unevaluatedProperties: false

examples:
  - |
    #include <dt-bindings/gpio/gpio.h>
    spi {
        #address-cells = <1>;
        #size-cells = <0>;

        flash@0 {
            compatible = "spansion,m25p80", "jedec,spi-nor";
            reg = <0>;
            spi-max-frequency = <40000000>;
            m25p,fast-read;
            reset-gpios = <&gpio 12 GPIO_ACTIVE_LOW>;
        };
    };
...