[PATCH v4 0/2] drm/imx: replace simple display pipe with atomic helpers

[Ze Huang]

struct drm_simple_display_pipe was meant to simplify simple DRM
drivers, but instead adds an extra wrapper around normal DRM atomic
helper setup. As noted in Documentation/gpu/todo.rst, remaining users
should be converted to regular atomic helpers and stop depending on the
simple-KMS interfaces.

The series replaces drm_simple_display_pipe_init() with explicit
primary plane, CRTC and encoder setup, and moves the old simple-pipe
callbacks into regular plane and CRTC helper callbacks named according
to local driver conventions.

The conversion preserves helper behavior that used to be implicit in
drm_simple_kms_helper.c, including plane-state validation, CRTC
primary-plane checks, affected-plane propagation, framebuffer prepare
handling, and existing event/vblank flow where applicable.

Result is less helper indirection and more explicit driver-side atomic
wiring, with no remaining simple-KMS dependency in this driver.

Changes are build-tested only. No hardware testing has been performed.

The patches are based on v7.3-rc2.

AI usage disclosure:
- AI tools were also used to review the code and suggest code changes for
  the DRM atomic conversion.

Thanks,
Ze Huang

Signed-off-by: Ze Huang <ze.huang@xxxxxxxxxxxxxxxx>
---
Changes in v4:
- Use drm_crtc_vblank_atomic_flush() instead of the driver's own flush
  callback.
- Replace the reset callbacks with the atomic_create_state helpers and use
  drm_mode_config_create_initial_state() in probe.
- Link to v3: https://lore.kernel.org/all/20260727-drm-simple-kms-removal-v3-0-de36e534f7a1@xxxxxxxxxxxxxxxx/

Changes in v3:
- Add a new preparatory patch to avoid duplicate clk_per enables in
  imx-lcdc pipe update after CRTC enable.
- Use commit-local atomic state in enable/update/check paths.
- Link to v2: https://patch.msgid.link/20260716-drm-simple-kms-removal-v2-1-7e4a6b8528e6@xxxxxxxxxxxxxxxx/

Changes in v2:
- use 'commit' as name of struct drm_atomic_commit in atomic helpers
- improve control flow in *_crtc_helper_atomic_check() and
  *_plane_helper_atomic_check()
- Moved page-flip/vblank event handling out of plane update paths and into
  CRTC atomic_flush(), using atomic_flush and disable paths
- decide clock disable by old crtc state
- add calls to drm_crtc_vblank_on() and drm_crtc_vblank_off() in crtc
  atomic_enable() and atomic_disbale()
- test crtc_state->enable before mode size check
- Link to v1: https://patch.msgid.link/20260705-drm-simple-kms-removal-v1-0-b4e1ca053623@xxxxxxxxxxxxxxxx

To: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
To: Maxime Ripard <mripard@xxxxxxxxxx>
To: Thomas Zimmermann <tzimmermann@xxxxxxx>
To: David Airlie <airlied@xxxxxxxxx>
To: Simona Vetter <simona@xxxxxxxx>
To: Frank Li <Frank.Li@xxxxxxx>
To: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
To: Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>
To: Fabio Estevam <festevam@xxxxxxxxx>
To: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
To: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
To: Marian Cichy <m.cichy@xxxxxxxxxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: imx@xxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx

---
Ze Huang (2):
      drm/imx/lcdc: avoid duplicate clk_per enable
      drm/imx: replace struct drm_simple_display_pipe with regular atomic helpers

 drivers/gpu/drm/imx/lcdc/imx-lcdc.c | 249 +++++++++++++++++++++++++-----------
 1 file changed, 175 insertions(+), 74 deletions(-)
---
base-commit: 5e036ce12de91c6fd674dad33b169c6150be2a7a
change-id: 20260919-b4-imx-simple-kms-v4-3f7d32e17548

Best regards,
--  
Ze Huang <ze.huang@xxxxxxxxxxxxxxxx>