Documentation/devicetree/bindings/memory-controllers/ti,gpmc-child.yaml

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/memory-controllers/ti,gpmc-child.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Texas Instruments GPMC Bus Child Nodes

maintainers:
  - Tony Lindgren <tony@atomide.com>
  - Roger Quadros <rogerq@kernel.org>

description:
  This binding is meant for the child nodes of the GPMC node. The node
  represents any device connected to the GPMC bus. It may be a Flash chip,
  RAM chip or Ethernet controller, etc. These properties are meant for
  configuring the GPMC settings/timings and will accompany the bindings
  supported by the respective device.

properties:
  reg: true

# GPMC Timing properties for child nodes. All are optional and default to 0.
  gpmc,sync-clk-ps:
    description: Minimum clock period for synchronous mode
    default: 0

# Chip-select signal timings corresponding to GPMC_CONFIG2:
  gpmc,cs-on-ns:
    description: Assertion time
    default: 0

  gpmc,cs-rd-off-ns:
    description: Read deassertion time
    default: 0

  gpmc,cs-wr-off-ns:
    description: Write deassertion time
    default: 0

# ADV signal timings corresponding to GPMC_CONFIG3:
  gpmc,adv-on-ns:
    description: Assertion time
    default: 0

  gpmc,adv-rd-off-ns:
    description: Read deassertion time
    default: 0

  gpmc,adv-wr-off-ns:
    description: Write deassertion time
    default: 0

  gpmc,adv-aad-mux-on-ns:
    description: Assertion time for AAD
    default: 0

  gpmc,adv-aad-mux-rd-off-ns:
    description: Read deassertion time for AAD
    default: 0

  gpmc,adv-aad-mux-wr-off-ns:
    description: Write deassertion time for AAD
    default: 0

# WE signals timings corresponding to GPMC_CONFIG4:
  gpmc,we-on-ns:
    description: Assertion time
    default: 0

  gpmc,we-off-ns:
    description: Deassertion time
    default: 0

# OE signals timings corresponding to GPMC_CONFIG4:
  gpmc,oe-on-ns:
    description: Assertion time
    default: 0

  gpmc,oe-off-ns:
    description: Deassertion time
    default: 0

  gpmc,oe-aad-mux-on-ns:
    description: Assertion time for AAD
    default: 0

  gpmc,oe-aad-mux-off-ns:
    description: Deassertion time for AAD
    default: 0

# Access time and cycle time timings (in nanoseconds) corresponding to
# GPMC_CONFIG5:
  gpmc,page-burst-access-ns:
    description: Multiple access word delay
    default: 0

  gpmc,access-ns:
    description: Start-cycle to first data valid delay
    default: 0

  gpmc,rd-cycle-ns:
    description: Total read cycle time
    default: 0

  gpmc,wr-cycle-ns:
    description: Total write cycle time
    default: 0

  gpmc,bus-turnaround-ns:
    description: Turn-around time between successive accesses
    default: 0

  gpmc,cycle2cycle-delay-ns:
    description: Delay between chip-select pulses
    default: 0

  gpmc,clk-activation-ns:
    description: GPMC clock activation time
    default: 0

  gpmc,wait-monitoring-ns:
    description: Start of wait monitoring with regard to valid data
    default: 0

# Boolean timing parameters. If property is present, parameter is enabled
# otherwise disabled.
  gpmc,adv-extra-delay:
    description: ADV signal is delayed by half GPMC clock
    type: boolean

  gpmc,cs-extra-delay:
    description: CS signal is delayed by half GPMC clock
    type: boolean

  gpmc,cycle2cycle-diffcsen:
    description: |
      Add "cycle2cycle-delay" between successive accesses
      to a different CS
    type: boolean

  gpmc,cycle2cycle-samecsen:
    description: |
      Add "cycle2cycle-delay" between successive accesses
      to the same CS
    type: boolean

  gpmc,oe-extra-delay:
    description: OE signal is delayed by half GPMC clock
    type: boolean

  gpmc,we-extra-delay:
    description: WE signal is delayed by half GPMC clock
    type: boolean

  gpmc,time-para-granularity:
    description: Multiply all access times by 2
    type: boolean

# The following two properties are applicable only to OMAP3+ and AM335x:
  gpmc,wr-access-ns:
    description: |
      In synchronous write mode, for single or
      burst accesses, defines the number of
      GPMC_FCLK cycles from start access time
      to the GPMC_CLK rising edge used by the
      memory device for the first data capture.
    default: 0

  gpmc,wr-data-mux-bus-ns:
    description: |
      In address-data multiplex mode, specifies
      the time when the first data is driven on
      the address-data bus.
    default: 0

# GPMC chip-select settings properties for child nodes. All are optional.
  gpmc,burst-length:
    description: Page/burst length.
    $ref: /schemas/types.yaml#/definitions/uint32
    enum: [0, 4, 8, 16]
    default: 0

  gpmc,burst-wrap:
    description: Enables wrap bursting
    type: boolean

  gpmc,burst-read:
    description: Enables read page/burst mode
    type: boolean

  gpmc,burst-write:
    description: Enables write page/burst mode
    type: boolean

  gpmc,device-width:
    description: |
      Total width of device(s) connected to a GPMC
      chip-select in bytes. The GPMC supports 8-bit
      and 16-bit devices and so this property must be
      1 or 2.
    $ref: /schemas/types.yaml#/definitions/uint32
    enum: [1, 2]
    default: 1

  gpmc,mux-add-data:
    description: |
      Address and data multiplexing configuration.
      Valid values are
      0 for Non multiplexed mode
      1 for address-address-data multiplexing mode and
      2 for address-data multiplexing mode.
    $ref: /schemas/types.yaml#/definitions/uint32
    enum: [0, 1, 2]

  gpmc,sync-read:
    description: |
      Enables synchronous read. Defaults to asynchronous
      is this is not set.
    type: boolean

  gpmc,sync-write:
    description: |
      Enables synchronous writes. Defaults to asynchronous
      is this is not set.
    type: boolean

  gpmc,wait-pin:
    description: |
      Wait-pin used by client. Must be less than "gpmc,num-waitpins".
    $ref: /schemas/types.yaml#/definitions/uint32

  ti,wait-pin-polarity:
    description: |
      Set the desired polarity for the selected wait pin.
      0 for active low, 1 for active high.
    $ref: /schemas/types.yaml#/definitions/uint32
    enum: [0, 1]

  gpmc,wait-on-read:
    description: Enables wait monitoring on reads.
    type: boolean

  gpmc,wait-on-write:
    description: Enables wait monitoring on writes.
    type: boolean

required:
  - reg

# the GPMC child will have its own native properties
additionalProperties: true