[PATCH v4 0/7] Thunderbolt and DP altmode support for cros-ec-typec

[Abhishek Pandit-Subedi]

Hi Heikki, Tzung-Bi et al,

This patch series adds support for alternate mode entry for the
cros-ec-typec driver for Displayport and Thunderbolt.

Thunderbolt support is added by adapting an RFC Heikki had posted
previously:

https://lore.kernel.org/linux-usb/20191230152857.43917-1-heikki.krogerus@xxxxxxxxxxxxxxx/

A few comments on the series:

* The cros-ec interface will not accept any VDOs/VDMs so we simply
  ignore any configurations we are passed (i.e. DPConfigure). This means
  the sysfs control of DP lanes won't work.
* ChromeOS has two modes of operation for alt-modes: entirely EC driven
  or AP-driven from userspace (via the typec daemon). Thus, we don't
  expect the kernel alt-mode drivers to auto-enter modes in all cases.
  This series allows auto-enter for displayport but disables it for TBT
  for this reason.

This was tested with a ChromeOS Brya device using kernel 6.6 and built
with allmodconfig for linux-usb.

Thanks,
Abhishek

Changes in v4:
- Large refactor to use cable_altmodes
- Fixed ordering of cable mode enter/exit (SOP', SOP", then port for
  enter; reverse order for exit)
- Other small fixes from v3 feedback
- memset struct typec_altmode_desc
- Add CONFIG_CROS_EC_TYPEC_ALTMODES for Makefile use
- Move ap_driven_altmode check to common vdm function
- Add locking to protect shared data
- Update enter/exit error messages
- Update Makefile + Kconfig to use CONFIG_CROS_EC_TYPEC_ALTMODES
- Add locking in vdm function

Changes in v3:
- Removed mode from altmode device ids
- Updated modalias for typecd bus to remove mode
- Re-ordered to start of series
- Revert rename of TYPEC_TBT_MODE
- Remove mode from typec_device_id
- Refactored typec_altmode_dp_data per review request
- Removed unused vdm operations during altmode registration
- Fix usage of TBT sid and mode.
- Removed unused vdm operations during altmode registration
- Set port.inactive = true instead of auto-enter.

Changes in v2:
- Update altmode_match to ignore mode entirely
- Also apply the same behavior to typec_match
- Use <linux/usb/typec_tbt.h> and add missing TBT_CABLE_ROUNDED
- Pass struct typec_thunderbolt_data to typec_altmode_notify
- Rename TYPEC_TBT_MODE to USB_TYPEC_TBT_MODE
- Use USB_TYPEC_TBT_SID and USB_TYPEC_TBT_MODE for device id
- Change module license to GPL due to checkpatch warning
- Refactored displayport into cros_typec_altmode.c to extract common
  implementation between altmodes
- Refactored thunderbolt support into cros_typec_altmode.c
- Only disable auto-enter for Thunderbolt
- Update commit message to clearly indicate the need for userspace
  intervention to enter TBT mode

Changes in v1:
- Delay cable + plug checks so that the module doesn't fail to probe
  if cable + plug information isn't available by the time the partner
  altmode is registered.
- Remove unncessary brace after if (IS_ERR(plug))

Abhishek Pandit-Subedi (6):
  usb: typec: Only use SVID for matching altmodes
  usb: typec: Print err when displayport fails to enter
  platform/chrome: cros_ec_typec: Update partner altmode active
  platform/chrome: cros_ec_typec: Displayport support
  platform/chrome: cros_ec_typec: Thunderbolt support
  platform/chrome: cros_ec_typec: Disable tbt on port

Heikki Krogerus (1):
  usb: typec: Add driver for Thunderbolt 3 Alternate Mode

 MAINTAINERS                                  |   3 +
 drivers/platform/chrome/Kconfig              |   7 +
 drivers/platform/chrome/Makefile             |   4 +
 drivers/platform/chrome/cros_ec_typec.c      |  48 ++-
 drivers/platform/chrome/cros_ec_typec.h      |   1 +
 drivers/platform/chrome/cros_typec_altmode.c | 369 ++++++++++++++++++
 drivers/platform/chrome/cros_typec_altmode.h |  48 +++
 drivers/usb/typec/altmodes/Kconfig           |   9 +
 drivers/usb/typec/altmodes/Makefile          |   2 +
 drivers/usb/typec/altmodes/displayport.c     |   5 +-
 drivers/usb/typec/altmodes/nvidia.c          |   2 +-
 drivers/usb/typec/altmodes/thunderbolt.c     | 387 +++++++++++++++++++
 drivers/usb/typec/bus.c                      |   6 +-
 drivers/usb/typec/class.c                    |   9 +-
 include/linux/usb/typec.h                    |   2 +
 include/linux/usb/typec_tbt.h                |   1 +
 scripts/mod/devicetable-offsets.c            |   1 -
 scripts/mod/file2alias.c                     |   4 +-
 18 files changed, 879 insertions(+), 29 deletions(-)
 create mode 100644 drivers/platform/chrome/cros_typec_altmode.c
 create mode 100644 drivers/platform/chrome/cros_typec_altmode.h
 create mode 100644 drivers/usb/typec/altmodes/thunderbolt.c

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2.47.0.338.g60cca15819-goog