#### Plugin: CCGX DMC

## Introduction

This plugin can flash firmware on Infineon (previously Cypress) CCGx DMC devices used in docks.

## Supported Protocols

This plugin supports the following protocol IDs:

- `com.cypress.ccgx.dmc` (deprecated)
- `com.infineon.ccgx.dmc`

### DMC Factory Mode

Dock Management Controller devices have a composite version that is used to describe the dock hardware as a whole, rather than enumerating and updating each sub-component separately. When OEMs have not followed the IHV-approved factory assembly process, the composite number is unset and fwupd would display `0.0.0.0` in the GUI and on the command line.

In fwupd >= 1.8.11 we detect if the device is in factory mode and set the version number to `0.0.0.1`. When the device is in factory mode any valid upgrade will be allowed, which means the user might be prompted to “update to” the same current version installed on the dock. For millions of devices this is both a waste of time, resources, and also would inconvenience the user with an additional process for no reason.

For devices that have been shipped in factory mode, but would like to avoid the update from `0.0.0.1` to the original version on the LVFS, can add a quirk entry which matches the `devx` subcomponent base version. In this example we match the parent VID, PID, the ComponentID and the `devx` base firmware version, setting the parent composite version to `0.0.0.15`.

    [USB\VID_2188&PID_0035&CID_05&VER_3.3.1.69]
    CcgxDmcCompositeVersion = 15

All the `devx` subcomponent versions can be shown on the console using:

    sudo fwupdtool –plugins ccgx get-devices –show-all –verbose

## Firmware Format

In composite firmware topology, a single firmware image contains metadata and firmware images of multiple devices including DMC itself in a dock system.

The daemon will decompress the cabinet archive and extract several firmware blobs in a combined image file format. See 4.4.1 Single Composite (Combined) Dock Image at https://www.cypress.com/file/387471/download for more details.

## GUID Generation

These devices use the standard USB DeviceInstanceId values, e.g.

- `USB\VID_1234&PID_5678`

## Update Behavior

The device usually presents in runtime HID mode, but on detach re-enumerates with with a DMC or HPI interface. On attach the device again re-enumerates back to the runtime HID mode.

## Vendor ID Security

The vendor ID is set from the USB vendor, for example set to `USB:0x04B4`

## Quirk Use

This plugin uses the following plugin-specific quirks:

### CcgxDmcTriggerCode

DMC devices need a specified trigger code to request the device to update the firmware and the trigger code depends on the devices.

    0x0: Do not update
    0x1: Update immediately
    0x2: Update after port disconnected

Since: 1.8.0

### CcgxDmcCompositeVersion

Set the parent composite version, as a 32 bit integer.

Since: 1.8.11

## External Interface Access

This plugin requires read/write access to `/dev/bus/usb`.

## Version Considerations

This plugin has been available since fwupd version `1.5.0`.

## Owners

Anyone can submit a pull request to modify this plugin, but the following people should be consulted before making major or functional changes:

- Brent Wu: `IfxBrent`