Documentation/devicetree/bindings/usb/am33xx-usb.txt

Source file repositories/reference/linux-study-clean/Documentation/devicetree/bindings/usb/am33xx-usb.txt

File Facts

System
Linux kernel
Corpus path
Documentation/devicetree/bindings/usb/am33xx-usb.txt
Extension
.txt
Size
6045 bytes
Lines
201
Domain
Support Tooling And Documentation
Bucket
Documentation
Inferred role
Support Tooling And Documentation: documentation
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

AM33xx MUSB
~~~~~~~~~~~~~~~
- compatible: ti,am33xx-usb
- reg: offset and length of the usbss register sets
- ti,hwmods : must be "usb_otg_hs"

The glue layer contains multiple child nodes. It is required to have
at least a control module node, USB node and a PHY node. The second USB
node and its PHY node are optional. The DMA node is also optional.

Reset module
~~~~~~~~~~~~
- compatible: ti,am335x-usb-ctrl-module
- reg: offset and length of the "USB control registers" in the "Control
  Module" block. A second offset and length for the USB wake up control
  in the same memory block.
- reg-names: "phy_ctrl" for the "USB control registers" and "wakeup" for
  the USB wake up control register.

USB PHY
~~~~~~~
compatible: ti,am335x-usb-phy
reg: offset and length of the "USB PHY" register space
ti,ctrl_mod: reference to the "reset module" node
reg-names: phy
The PHY should have a "phy" alias numbered properly in the alias
node.

USB
~~~
- compatible: ti,musb-am33xx
- reg: offset and length of "USB Controller Registers", and offset and
  length of "USB Core" register space.
- reg-names: control for the ""USB Controller Registers" and "mc" for
  "USB Core" register space
- interrupts: USB interrupt number
- interrupt-names: mc
- dr_mode: Should be one of "host", "peripheral" or "otg".
- mentor,multipoint: Should be "1" indicating the musb controller supports
  multipoint. This is a MUSB configuration-specific setting.
- mentor,num-eps: Specifies the number of endpoints. This is also a
  MUSB configuration-specific setting. Should be set to "16"
- mentor,ram-bits: Specifies the ram address size. Should be set to "12"
- mentor,power: Should be "500". This signifies the controller can supply up to
  500mA when operating in host mode.
- phys: reference to the USB phy
- dmas: specifies the dma channels
- dma-names: specifies the names of the channels. Use "rxN" for receive
  and "txN" for transmit endpoints. N specifies the endpoint number.

The controller should have an "usb" alias numbered properly in the alias
node.

DMA
~~~
- compatible: ti,am3359-cppi41
- reg: offset and length of the following register spaces: USBSS, USB
  CPPI DMA Controller, USB CPPI DMA Scheduler, USB Queue Manager
- reg-names: glue, controller, scheduler, queuemgr
- #dma-cells: should be set to 2. The first number represents the
  endpoint number (0 … 14 for endpoints 1 … 15 on instance 0 and 15 … 29
  for endpoints 1 … 15 on instance 1). The second number is 0 for RX and
  1 for TX transfers.
- dma-channels: should be set to 30 representing the 15 endpoints for
  each USB instance.
- #dma-channels: deprecated

Example:
~~~~~~~~
The following example contains all the nodes as used on am335x-evm:

Annotation

Implementation Notes