[PATCHv3 00/13] media/drm: cec: add HPD_PRESENT

[Hans Verkuil <hverkuil+cisco@kernel.org>]

Using the media CEC framework the application receives events when the
Physical and/or Logical Addresses change. However, if the Physical Address
changes to f.f.f.f (Invalid), it does not know whether that is because the
HDMI link is disconnected, or because the EDID does not provide a valid
Physical Address. That can happen because the display does not support CEC,
as is the case for DisplayPort inputs or PC monitors.

This is important information to have but this is currently missing.

This series adds support for that.

Currently drivers set the physical address either with cec_s_phys_addr() or
with cec_phys_addr_invalidate(), where the second is just a helper
function that calls cec_s_phys_addr with CEC_PHYS_ADDR_INVALID. There
are also cec_notifier_ counterparts.

Change the behavior so that cec_s_phys_addr() is called whenever the HPD
is high. In that case CEC_PHYS_ADDR_INVALID means that the EDID is
present but does not contain a valid PA. And cec_phys_addr_invalidate()
is only called when the video link is disconnected.

Most CEC drivers already did that, except for the few that are fixed in the
first 6 patches.

The remaining patches implement the new functionality where the CEC
framework actually reports whether or not the HPD was present, based
on whether cec_s_phys_addr or cec_phys_addr_invalidate was called.

Note: I think cec_phys_addr_invalidate should be renamed to something like
cec_phys_addr_disconnect given the changes semantics of this function.
I will tackle that once this series is in.

The drm patches can either be queued up in the drm subsystem independently
of the remaining patches, or I can take them through the media subsytem
as part of the series, but then I need an Acked/Reviewed-by.

Regards,

	Hans

Changes in v3:

- Renamed EDID_PRESENT to HPD_PRESENT, since that's what it really is.

Changes in v2 (based on sashiko reviews):

- missed one incorrect cec_notifier_set_phys_addr call in sti_hdmi.c
- cec_notifier_cec_adap_register didn't call cec_phys_addr_invalidate
  if an earlier cec_notifier_phys_addr_invalidate call indicated that
  there is no EDID.
- sending the initial state change event didn't set the
  CEC_EVENT_FL_STATE_EDID_PRESENT flag if needed.

Hans Verkuil (13):
  gpu: drm: sti: call cec_notifier_phys_addr_invalidate if no HPD
  gpu: drm: exynos: call cec_notifier_phys_addr_invalidate if no HPD
  gpu: drm: omapdrm: call cec_s_phys_addr only if HPD is present
  media: i2c: adv7511-v4l2: call cec_s_phys_addr only if HPD is high
  media: cec: extron-da-hd-4k-plus: call cec_s_phys_addr only if HPD is
    high
  media: cec: core: improve cec_notifier_phys_addr_invalidate
  media: uapi: cec.h: add
    CEC_CAP_HAS_HPD_PRESENT/CEC_LOG_ADDRS_FL_HPD_PRESENT
  Documentation: media: document HPD_PRESENT cap and flag.
  media: cec: core: add support for HPD_PRESENT
  media: uapi: cec.h: add CEC_EVENT_FL_STATE_HPD_PRESENT flag
  Documentation: media: cec-ioc-dqevent.rst: document STATE_HPD_PRESENT
    flag
  media: cec: core: implement CEC_EVENT_FL_STATE_HPD_PRESENT
  Documentation: media: document cec_phys_addr_invalidate

 Documentation/driver-api/media/cec-core.rst   | 10 +++-
 .../media/cec/cec-ioc-adap-g-caps.rst         | 11 ++++
 .../media/cec/cec-ioc-adap-g-log-addrs.rst    | 10 ++++
 .../media/cec/cec-ioc-dqevent.rst             | 10 ++++
 drivers/gpu/drm/exynos/exynos_hdmi.c          |  2 +-
 drivers/gpu/drm/omapdrm/dss/hdmi4.c           |  7 ++-
 drivers/gpu/drm/omapdrm/dss/hdmi4_cec.c       |  5 ++
 drivers/gpu/drm/omapdrm/dss/hdmi4_cec.h       |  5 ++
 drivers/gpu/drm/sti/sti_hdmi.c                |  4 +-
 drivers/media/cec/core/cec-adap.c             | 51 ++++++++++++++++---
 drivers/media/cec/core/cec-api.c              | 13 +++--
 drivers/media/cec/core/cec-core.c             |  4 +-
 drivers/media/cec/core/cec-notifier.c         | 26 +++++++++-
 drivers/media/cec/core/cec-priv.h             |  3 +-
 .../extron-da-hd-4k-plus.c                    |  8 ++-
 drivers/media/i2c/adv7511-v4l2.c              |  2 +-
 include/media/cec-notifier.h                  | 33 +++++++-----
 include/media/cec.h                           | 27 +++++-----
 include/uapi/linux/cec.h                      | 29 ++++++-----
 19 files changed, 193 insertions(+), 67 deletions(-)

-- 
2.53.0