Some notebooks have a button to disable the camera (not to be mistaken
with the mechanical cover). This is a standard GPIO linked to the
camera via the ACPI table.

4 years ago we added support for this button in UVC via the Privacy control.
This has three issues:
- If the camera has its own privacy control, it will be masked.
- We need to power-up the camera to read the privacy control gpio.
- Other drivers have not followed this approach and have used evdev.

We tried to fix the power-up issues implementing "granular power
saving" but it has been more complicated than anticipated...

This patchset implements the Privacy GPIO as a evdev.

The first patch of this set is already in Laurent's tree... but I
include it to get some CI coverage.

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
Changes in v3:
- CodeStyle (Thanks Sakari)
- Re-implement as input device
- Make the code depend on UVC_INPUT_EVDEV
- Link to v2: https://lore.kernel.org/r/20241108-uvc-subdev-v2-0-85d8a0...

Changes in v2:
- Rebase on top of https://patchwork.linuxtv.org/project/linux-media/patch/2...
- Create uvc_gpio_cleanup and uvc_gpio_deinit
- Refactor quirk: do not disable irq
- Change define number for MEDIA_ENT_F_GPIO
- Link to v1: https://lore.kernel.org/r/20241031-uvc-subdev-v1-0-a68331...

---
Ricardo Ribalda (8):
      media: uvcvideo: Fix crash during unbind if gpio unit is in use
      media: uvcvideo: Factor out gpio functions to its own file
      media: uvcvideo: Re-implement privacy GPIO as an input device
      Revert "media: uvcvideo: Allow entity-defined get_info and get_cur"
      media: uvcvideo: Create ancillary link for GPIO subdevice
      media: v4l2-core: Add new MEDIA_ENT_F_GPIO
      media: uvcvideo: Use MEDIA_ENT_F_GPIO for the GPIO entity
      media: uvcvideo: Introduce UVC_QUIRK_PRIVACY_DURING_STREAM

 .../userspace-api/media/mediactl/media-types.rst   |   4 +
 drivers/media/usb/uvc/Kconfig                      |   2 +-
 drivers/media/usb/uvc/Makefile                     |   3 +
 drivers/media/usb/uvc/uvc_ctrl.c                   |  40 +-----
 drivers/media/usb/uvc/uvc_driver.c                 | 112 +---------------
 drivers/media/usb/uvc/uvc_entity.c                 |  21 ++-
 drivers/media/usb/uvc/uvc_gpio.c                   | 144 +++++++++++++++++++++
 drivers/media/usb/uvc/uvc_status.c                 |  13 +-
 drivers/media/usb/uvc/uvc_video.c                  |   4 +
 drivers/media/usb/uvc/uvcvideo.h                   |  31 +++--
 drivers/media/v4l2-core/v4l2-async.c               |   3 +-
 include/uapi/linux/media.h                         |   1 +
 12 files changed, 223 insertions(+), 155 deletions(-)
---
base-commit: 1b3bb4d69f20be5931abc18a6dbc24ff687fa780
change-id: 20241030-uvc-subdev-89f4467a00b5

Best regards,
-- 
Ricardo Ribalda <ribalda@chromium.org>