[PATCH v2 0/9] Touch Bar support for T2 Macs

[Aditya Garg <gargaditya08@live.com>]

Hi Maintainers

The Touch Bars found on x86 Macs support two USB configurations: one
where the device presents itself as a HID keyboard and can display
predefined sets of keys, and one where the operating system has full
control over what is displayed.

This patch series adds support for both the configurations.

The hid-appletb-bl driver adds support for the backlight of the Touch Bar.
This enables the user to control the brightness of the Touch Bar from
userspace. The Touch Bar supports 3 modes here: Max brightness, Dim and Off.
So, daemons, used to manage Touch Bar can easily manage these modes by writing
to /sys/class/backlight/appletb_backlight/brightness. It is needed by both the
configurations of the Touch Bar.

The hid-appletb-kbd adds support for the first (predefined keys) configuration.
There are 4 modes here: Esc key only, Fn mode, Media keys and No keys.
Mode can be changed by writing to /sys/bus/hid/drivers/hid-appletb-kbd/<dev>/mode
This configuration is what Windows uses with the official Apple Bootcamp drivers.

Rest patches support the second configuration, where the OS has full control
on what's displayed on the Touch Bar. It is achieved by the patching the
hid-multitouch driver to add support for touch feedback from the Touch Bar
and the appletbdrm driver, that displays what we want to on the Touch Bar.
This configuration is what macOS uses.

The appletbdrm driver is based on the similar driver made for Windows by
imbushuo [1].

Currently, a daemon named tiny-dfr [2] is being used to display function keys
and media controls using the second configuration for both Apple Silicon and
T2 Macs.

A daemon for the first configuration is being developed, but that's a userspace
thing.

[1]: https://github.com/imbushuo/DFRDisplayKm
[2]: https://github.com/WhatAmISupposedToPutHere/tiny-dfr

v2:
  1. Cleaned up some code in the hid-appletb-kbd driver.
  2. Fixed wrong subject in drm/format-helper patch.
  3. Fixed Co-developed-by wrongly added to hid-multitouch patch.

Kerem Karabay (9):
  HID: hid-appletb-bl: add driver for the backlight of Apple Touch Bars
  HID: hid-appletb-kbd: add driver for the keyboard mode of Apple Touch
    Bars
  HID: multitouch: support getting the contact ID from
    HID_DG_TRANSDUCER_INDEX fields
  HID: multitouch: support getting the tip state from HID_DG_TOUCH
    fields
  HID: multitouch: take cls->maxcontacts into account for devices
    without a HID_DG_CONTACTMAX field too
  HID: multitouch: allow specifying if a device is direct in a class
  HID: multitouch: add device ID for Apple Touch Bars
  drm/format-helper: Add conversion from XRGB8888 to BGR888
  drm/tiny: add driver for Apple Touch Bars in x86 Macs

 .../ABI/testing/sysfs-driver-hid-appletb-kbd  |  13 +
 MAINTAINERS                                   |  12 +
 drivers/gpu/drm/drm_format_helper.c           |  54 ++
 .../gpu/drm/tests/drm_format_helper_test.c    |  81 +++
 drivers/gpu/drm/tiny/Kconfig                  |  12 +
 drivers/gpu/drm/tiny/Makefile                 |   1 +
 drivers/gpu/drm/tiny/appletbdrm.c             | 624 ++++++++++++++++++
 drivers/hid/Kconfig                           |  22 +
 drivers/hid/Makefile                          |   2 +
 drivers/hid/hid-appletb-bl.c                  | 206 ++++++
 drivers/hid/hid-appletb-kbd.c                 | 303 +++++++++
 drivers/hid/hid-multitouch.c                  |  60 +-
 drivers/hid/hid-quirks.c                      |   8 +-
 include/drm/drm_format_helper.h               |   3 +
 14 files changed, 1385 insertions(+), 16 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-driver-hid-appletb-kbd
 create mode 100644 drivers/gpu/drm/tiny/appletbdrm.c
 create mode 100644 drivers/hid/hid-appletb-bl.c
 create mode 100644 drivers/hid/hid-appletb-kbd.c

-- 
2.39.3 (Apple Git-146)