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

[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@oss.qualcomm.com>
---
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@oss.qualcomm.com/

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@oss.qualcomm.com/

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@oss.qualcomm.com

To: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
To: Maxime Ripard <mripard@kernel.org>
To: Thomas Zimmermann <tzimmermann@suse.de>
To: David Airlie <airlied@gmail.com>
To: Simona Vetter <simona@ffwll.ch>
To: Frank Li <Frank.Li@nxp.com>
To: Sascha Hauer <s.hauer@pengutronix.de>
To: Pengutronix Kernel Team <kernel@pengutronix.de>
To: Fabio Estevam <festevam@gmail.com>
To: Philipp Zabel <p.zabel@pengutronix.de>
To: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
To: Marian Cichy <m.cichy@pengutronix.de>
Cc: dri-devel@lists.freedesktop.org
Cc: imx@lists.linux.dev
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org

---
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@oss.qualcomm.com>

[PATCH v4 1/2] drm/imx/lcdc: avoid duplicate clk_per enable

[Ze Huang]

The simple-KMS helper calls the pipe update after enabling the CRTC.
On an enable commit, imx_lcdc_pipe_enable() already programs the
mode and enables clk_per. The following pipe update sees the plane move
from no CRTC to the active CRTC, treats it as a mode update, and calls
imx_lcdc_update_hw_registers() again.

That second call has no old CRTC state to disable clk_per first, but it
enables clk_per again at the end. The disable path only drops one
reference, leaving clk_per enabled after each on/off cycle.

Skip the register update from the pipe update path when the CRTC already
needs a modeset. The enable path has already programmed the hardware for
that commit; keep the event handling in pipe update unchanged.

Fixes: c87e859cdeb5 ("drm/imx/lcdc: Implement DRM driver for imx25")
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Ze Huang <ze.huang@oss.qualcomm.com>
---
 drivers/gpu/drm/imx/lcdc/imx-lcdc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/imx/lcdc/imx-lcdc.c b/drivers/gpu/drm/imx/lcdc/imx-lcdc.c
index c67fe80b8115..e00e52c1c46e 100644
--- a/drivers/gpu/drm/imx/lcdc/imx-lcdc.c
+++ b/drivers/gpu/drm/imx/lcdc/imx-lcdc.c
@@ -310,7 +310,8 @@ static void imx_lcdc_pipe_update(struct drm_simple_display_pipe *pipe,
 	else if (old_crtc != crtc)
 		mode_changed = true;
 
-	imx_lcdc_update_hw_registers(pipe, old_state, mode_changed);
+	if (!drm_atomic_crtc_needs_modeset(crtc->state))
+		imx_lcdc_update_hw_registers(pipe, old_state, mode_changed);
 
 	if (event) {
 		crtc->state->event = NULL;

-- 
2.55.0

[PATCH v4 2/2] drm/imx: replace struct drm_simple_display_pipe with regular atomic helpers

[Ze Huang]

Convert i.MX LCDC to explicit primary plane, CRTC and encoder objects.
Keep no-scaling plane check and GEM framebuffer prepare callback from
simple-KMS path.

Wire the vblank lifecycle explicitly with CRTC vblank callbacks and
drm_crtc_vblank_on()/drm_crtc_vblank_off(). Use the old CRTC state in
the disable path for clock unwinding so the clock reference count
remains paired with the previous active state.

Use the atomic_create_state helpers with
drm_mode_config_create_initial_state() in probe, and
drm_crtc_vblank_atomic_flush() for the flush callback.

Signed-off-by: Ze Huang <ze.huang@oss.qualcomm.com>
---
 drivers/gpu/drm/imx/lcdc/imx-lcdc.c | 250 +++++++++++++++++++++++++-----------
 1 file changed, 175 insertions(+), 75 deletions(-)

diff --git a/drivers/gpu/drm/imx/lcdc/imx-lcdc.c b/drivers/gpu/drm/imx/lcdc/imx-lcdc.c
index e00e52c1c46e..8f0a0d4cf61a 100644
--- a/drivers/gpu/drm/imx/lcdc/imx-lcdc.c
+++ b/drivers/gpu/drm/imx/lcdc/imx-lcdc.c
@@ -2,6 +2,7 @@
 // SPDX-FileCopyrightText: 2020 Marian Cichy <M.Cichy@pengutronix.de>
 
 #include <drm/clients/drm_client_setup.h>
+#include <drm/drm_atomic.h>
 #include <drm/drm_bridge.h>
 #include <drm/drm_bridge_connector.h>
 #include <drm/drm_damage_helper.h>
@@ -14,10 +15,11 @@
 #include <drm/drm_gem_dma_helper.h>
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_of.h>
+#include <drm/drm_plane_helper.h>
 #include <drm/drm_print.h>
 #include <drm/drm_probe_helper.h>
-#include <drm/drm_simple_kms_helper.h>
 #include <drm/drm_vblank.h>
+#include <drm/drm_vblank_helper.h>
 #include <linux/bitfield.h>
 #include <linux/clk.h>
 #include <linux/dma-mapping.h>
@@ -101,7 +103,9 @@
 
 struct imx_lcdc {
 	struct drm_device drm;
-	struct drm_simple_display_pipe pipe;
+	struct drm_plane plane;
+	struct drm_crtc crtc;
+	struct drm_encoder encoder;
 	struct drm_connector *connector;
 	void __iomem *base;
 
@@ -134,14 +138,15 @@ static unsigned int imx_lcdc_get_format(unsigned int drm_format)
 	}
 }
 
-static void imx_lcdc_update_hw_registers(struct drm_simple_display_pipe *pipe,
-					 struct drm_plane_state *old_state,
+static void imx_lcdc_update_hw_registers(struct drm_crtc *crtc,
+					 struct drm_crtc_state *old_crtc_state,
+					 struct drm_crtc_state *new_crtc_state,
+					 struct drm_plane_state *new_state,
 					 bool mode_set)
 {
-	struct drm_crtc *crtc = &pipe->crtc;
-	struct drm_plane_state *new_state = pipe->plane.state;
+	struct imx_lcdc *lcdc = imx_lcdc_from_drmdev(crtc->dev);
+	const struct drm_display_mode *mode = &new_crtc_state->mode;
 	struct drm_framebuffer *fb = new_state->fb;
-	struct imx_lcdc *lcdc = imx_lcdc_from_drmdev(pipe->crtc.dev);
 	u32 lpcr, lvcr, lhcr;
 	u32 framesize;
 	dma_addr_t addr;
@@ -154,24 +159,24 @@ static void imx_lcdc_update_hw_registers(struct drm_simple_display_pipe *pipe,
 		return;
 
 	/* Disable PER clock to make register write possible */
-	if (old_state && old_state->crtc && old_state->crtc->enabled)
+	if (old_crtc_state && old_crtc_state->enable)
 		clk_disable_unprepare(lcdc->clk_per);
 
 	/* Framesize */
-	framesize = FIELD_PREP(IMX21LCDC_LSR_XMAX, crtc->mode.hdisplay >> 4) |
-		FIELD_PREP(IMX21LCDC_LSR_YMAX, crtc->mode.vdisplay);
+	framesize = FIELD_PREP(IMX21LCDC_LSR_XMAX, mode->hdisplay >> 4) |
+		FIELD_PREP(IMX21LCDC_LSR_YMAX, mode->vdisplay);
 	writel(framesize, lcdc->base + IMX21LCDC_LSR);
 
 	/* HSYNC */
-	lhcr = FIELD_PREP(IMX21LCDC_LHCR_HFPORCH, crtc->mode.hsync_start - crtc->mode.hdisplay - 1) |
-		FIELD_PREP(IMX21LCDC_LHCR_HWIDTH, crtc->mode.hsync_end - crtc->mode.hsync_start - 1) |
-		FIELD_PREP(IMX21LCDC_LHCR_HBPORCH, crtc->mode.htotal - crtc->mode.hsync_end - 3);
+	lhcr = FIELD_PREP(IMX21LCDC_LHCR_HFPORCH, mode->hsync_start - mode->hdisplay - 1) |
+		FIELD_PREP(IMX21LCDC_LHCR_HWIDTH, mode->hsync_end - mode->hsync_start - 1) |
+		FIELD_PREP(IMX21LCDC_LHCR_HBPORCH, mode->htotal - mode->hsync_end - 3);
 	writel(lhcr, lcdc->base + IMX21LCDC_LHCR);
 
 	/* VSYNC */
-	lvcr = FIELD_PREP(IMX21LCDC_LVCR_VFPORCH, crtc->mode.vsync_start - crtc->mode.vdisplay) |
-		FIELD_PREP(IMX21LCDC_LVCR_VWIDTH, crtc->mode.vsync_end - crtc->mode.vsync_start) |
-		FIELD_PREP(IMX21LCDC_LVCR_VBPORCH, crtc->mode.vtotal - crtc->mode.vsync_end);
+	lvcr = FIELD_PREP(IMX21LCDC_LVCR_VFPORCH, mode->vsync_start - mode->vdisplay) |
+		FIELD_PREP(IMX21LCDC_LVCR_VWIDTH, mode->vsync_end - mode->vsync_start) |
+		FIELD_PREP(IMX21LCDC_LVCR_VBPORCH, mode->vtotal - mode->vsync_end);
 	writel(lvcr, lcdc->base + IMX21LCDC_LVCR);
 
 	lpcr = readl(lcdc->base + IMX21LCDC_LPCR);
@@ -183,19 +188,20 @@ static void imx_lcdc_update_hw_registers(struct drm_simple_display_pipe *pipe,
 	writel(new_state->fb->pitches[0] / 4, lcdc->base + IMX21LCDC_LVPWR);
 
 	/* Enable PER clock */
-	if (new_state->crtc->enabled)
+	if (new_crtc_state->enable)
 		clk_prepare_enable(lcdc->clk_per);
 }
 
-static void imx_lcdc_pipe_enable(struct drm_simple_display_pipe *pipe,
-				 struct drm_crtc_state *crtc_state,
-				 struct drm_plane_state *plane_state)
+static void imx_lcdc_crtc_helper_atomic_enable(struct drm_crtc *crtc,
+					       struct drm_atomic_commit *commit)
 {
 	int ret;
 	int clk_div;
 	int bpp;
-	struct imx_lcdc *lcdc = imx_lcdc_from_drmdev(pipe->crtc.dev);
-	struct drm_display_mode *mode = &pipe->crtc.mode;
+	struct imx_lcdc *lcdc = imx_lcdc_from_drmdev(crtc->dev);
+	struct drm_crtc_state *cstate = drm_atomic_get_new_crtc_state(commit, crtc);
+	struct drm_plane_state *pstate = drm_atomic_get_new_plane_state(commit, &lcdc->plane);
+	struct drm_display_mode *mode = &cstate->mode;
 	struct drm_display_info *disp_info = &lcdc->connector->display_info;
 	const int hsync_pol = (mode->flags & DRM_MODE_FLAG_PHSYNC) ? 0 : 1;
 	const int vsync_pol = (mode->flags & DRM_MODE_FLAG_PVSYNC) ? 0 : 1;
@@ -206,7 +212,7 @@ static void imx_lcdc_pipe_enable(struct drm_simple_display_pipe *pipe,
 
 	clk_div = DIV_ROUND_CLOSEST_ULL(clk_get_rate(lcdc->clk_per),
 					mode->clock * 1000);
-	bpp = imx_lcdc_get_format(plane_state->fb->format->format);
+	bpp = imx_lcdc_get_format(pstate->fb->format->format);
 
 	writel(FIELD_PREP(IMX21LCDC_LPCR_PCD, clk_div - 1) |
 	       FIELD_PREP(IMX21LCDC_LPCR_LPPOL, hsync_pol) |
@@ -230,40 +236,46 @@ static void imx_lcdc_pipe_enable(struct drm_simple_display_pipe *pipe,
 
 	ret = clk_prepare_enable(lcdc->clk_ipg);
 	if (ret) {
-		dev_err(pipe->crtc.dev->dev, "Cannot enable ipg clock: %pe\n", ERR_PTR(ret));
+		dev_err(crtc->dev->dev, "Cannot enable ipg clock: %pe\n", ERR_PTR(ret));
 		return;
 	}
 	ret = clk_prepare_enable(lcdc->clk_ahb);
 	if (ret) {
-		dev_err(pipe->crtc.dev->dev, "Cannot enable ahb clock: %pe\n", ERR_PTR(ret));
+		dev_err(crtc->dev->dev, "Cannot enable ahb clock: %pe\n", ERR_PTR(ret));
 
 		clk_disable_unprepare(lcdc->clk_ipg);
 
 		return;
 	}
 
-	imx_lcdc_update_hw_registers(pipe, NULL, true);
+	imx_lcdc_update_hw_registers(crtc, NULL, cstate, pstate, true);
 
 	/* Enable VBLANK Interrupt */
 	writel(INTR_EOF, lcdc->base + IMX21LCDC_LIER);
+
+	drm_crtc_vblank_on(crtc);
 }
 
-static void imx_lcdc_pipe_disable(struct drm_simple_display_pipe *pipe)
+static void imx_lcdc_crtc_helper_atomic_disable(struct drm_crtc *crtc,
+						struct drm_atomic_commit *commit)
 {
-	struct imx_lcdc *lcdc = imx_lcdc_from_drmdev(pipe->crtc.dev);
-	struct drm_crtc *crtc = &lcdc->pipe.crtc;
+	struct drm_crtc_state *old_crtc_state = drm_atomic_get_old_crtc_state(commit, crtc);
+	struct drm_crtc_state *new_crtc_state = drm_atomic_get_new_crtc_state(commit, crtc);
+	struct imx_lcdc *lcdc = imx_lcdc_from_drmdev(crtc->dev);
 	struct drm_pending_vblank_event *event;
 
+	drm_crtc_vblank_off(crtc);
+
 	clk_disable_unprepare(lcdc->clk_ahb);
 	clk_disable_unprepare(lcdc->clk_ipg);
 
-	if (pipe->crtc.enabled)
+	if (old_crtc_state->enable)
 		clk_disable_unprepare(lcdc->clk_per);
 
 	spin_lock_irq(&lcdc->drm.event_lock);
-	event = crtc->state->event;
+	event = new_crtc_state->event;
 	if (event) {
-		crtc->state->event = NULL;
+		new_crtc_state->event = NULL;
 		drm_crtc_send_vblank_event(crtc, event);
 	}
 	spin_unlock_irq(&lcdc->drm.event_lock);
@@ -272,66 +284,132 @@ static void imx_lcdc_pipe_disable(struct drm_simple_display_pipe *pipe)
 	writel(0, lcdc->base + IMX21LCDC_LIER);
 }
 
-static int imx_lcdc_pipe_check(struct drm_simple_display_pipe *pipe,
-			       struct drm_plane_state *plane_state,
-			       struct drm_crtc_state *crtc_state)
+static int imx_lcdc_crtc_helper_atomic_check(struct drm_crtc *crtc,
+					     struct drm_atomic_commit *commit)
 {
+	struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(commit, crtc);
+	struct drm_crtc_state *old_crtc_state = drm_atomic_get_old_crtc_state(commit, crtc);
 	const struct drm_display_mode *mode = &crtc_state->mode;
-	const struct drm_display_mode *old_mode = &pipe->crtc.state->mode;
+	const struct drm_display_mode *old_mode = &old_crtc_state->mode;
+	int ret;
+
+	if (crtc_state->enable) {
+		ret = drm_atomic_helper_check_crtc_primary_plane(crtc_state);
+		if (ret)
+			return ret;
+	}
 
-	if (mode->hdisplay < LCDC_MIN_XRES || mode->hdisplay > LCDC_MAX_XRES ||
-	    mode->vdisplay < LCDC_MIN_YRES || mode->vdisplay > LCDC_MAX_YRES ||
-	    mode->hdisplay % 0x10) { /* must be multiple of 16 */
-		drm_err(pipe->crtc.dev, "unsupported display mode (%u x %u)\n",
+	if (crtc_state->enable &&
+	    (mode->hdisplay < LCDC_MIN_XRES || mode->hdisplay > LCDC_MAX_XRES ||
+	     mode->vdisplay < LCDC_MIN_YRES || mode->vdisplay > LCDC_MAX_YRES ||
+	     mode->hdisplay % 0x10)) { /* must be multiple of 16 */
+		drm_err(crtc->dev, "unsupported display mode (%u x %u)\n",
 			mode->hdisplay, mode->vdisplay);
 		return -EINVAL;
 	}
 
-	crtc_state->mode_changed =
-		old_mode->hdisplay != mode->hdisplay ||
-		old_mode->vdisplay != mode->vdisplay;
+	if (old_mode->hdisplay != mode->hdisplay ||
+	    old_mode->vdisplay != mode->vdisplay)
+		crtc_state->mode_changed = true;
 
-	return 0;
+	return drm_atomic_add_affected_planes(commit, crtc);
 }
 
-static void imx_lcdc_pipe_update(struct drm_simple_display_pipe *pipe,
-				 struct drm_plane_state *old_state)
+static void imx_lcdc_plane_helper_atomic_update(struct drm_plane *plane,
+						struct drm_atomic_commit *commit)
 {
-	struct drm_crtc *crtc = &pipe->crtc;
-	struct drm_pending_vblank_event *event = crtc->state->event;
-	struct drm_plane_state *new_state = pipe->plane.state;
+	struct drm_plane_state *old_state = drm_atomic_get_old_plane_state(commit, plane);
+	struct drm_plane_state *new_state = drm_atomic_get_new_plane_state(commit, plane);
+	struct drm_crtc *crtc = new_state->crtc;
+	struct drm_crtc_state *old_crtc_state = NULL;
+	struct drm_crtc_state *new_crtc_state;
 	struct drm_framebuffer *fb = new_state->fb;
 	struct drm_framebuffer *old_fb = old_state->fb;
 	struct drm_crtc *old_crtc = old_state->crtc;
 	bool mode_changed = false;
 
+	if (!fb || !crtc)
+		return;
+
+	if (old_crtc)
+		old_crtc_state = drm_atomic_get_old_crtc_state(commit, old_crtc);
+
+	new_crtc_state = drm_atomic_get_new_crtc_state(commit, crtc);
+	if (!new_crtc_state)
+		return;
+
 	if (old_fb && old_fb->format != fb->format)
 		mode_changed = true;
 	else if (old_crtc != crtc)
 		mode_changed = true;
 
-	if (!drm_atomic_crtc_needs_modeset(crtc->state))
-		imx_lcdc_update_hw_registers(pipe, old_state, mode_changed);
+	if (!drm_atomic_crtc_needs_modeset(new_crtc_state))
+		imx_lcdc_update_hw_registers(crtc, old_crtc_state, new_crtc_state,
+					     new_state, mode_changed);
+}
 
-	if (event) {
-		crtc->state->event = NULL;
+static int imx_lcdc_plane_helper_atomic_check(struct drm_plane *plane,
+					      struct drm_atomic_commit *commit)
+{
+	struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(commit, plane);
+	struct drm_crtc_state *crtc_state = NULL;
 
-		spin_lock_irq(&crtc->dev->event_lock);
+	if (plane_state->crtc) {
+		crtc_state = drm_atomic_get_crtc_state(commit, plane_state->crtc);
+		if (IS_ERR(crtc_state))
+			return PTR_ERR(crtc_state);
+	}
 
-		if (crtc->state->active && drm_crtc_vblank_get(crtc) == 0)
-			drm_crtc_arm_vblank_event(crtc, event);
-		else
-			drm_crtc_send_vblank_event(crtc, event);
+	return drm_atomic_helper_check_plane_state(plane_state, crtc_state,
+						   DRM_PLANE_NO_SCALING,
+						   DRM_PLANE_NO_SCALING,
+						   false, false);
+}
 
-		spin_unlock_irq(&crtc->dev->event_lock);
-	}
+static const struct drm_plane_helper_funcs imx_lcdc_plane_helper_funcs = {
+	.prepare_fb	= drm_gem_plane_helper_prepare_fb,
+	.atomic_check	= imx_lcdc_plane_helper_atomic_check,
+	.atomic_update	= imx_lcdc_plane_helper_atomic_update,
+};
+
+static const struct drm_plane_funcs imx_lcdc_plane_funcs = {
+	.update_plane		= drm_atomic_helper_update_plane,
+	.disable_plane		= drm_atomic_helper_disable_plane,
+	.destroy		= drm_plane_cleanup,
+	.atomic_create_state	= drm_atomic_helper_plane_create_state,
+	.atomic_duplicate_state	= drm_atomic_helper_plane_duplicate_state,
+	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
+};
+
+static const struct drm_crtc_helper_funcs imx_lcdc_crtc_helper_funcs = {
+	.atomic_check	= imx_lcdc_crtc_helper_atomic_check,
+	.atomic_enable	= imx_lcdc_crtc_helper_atomic_enable,
+	.atomic_disable	= imx_lcdc_crtc_helper_atomic_disable,
+	.atomic_flush	= drm_crtc_vblank_atomic_flush,
+};
+
+static int imx_lcdc_crtc_enable_vblank(struct drm_crtc *crtc)
+{
+	return 0;
 }
 
-static const struct drm_simple_display_pipe_funcs imx_lcdc_pipe_funcs = {
-	.enable = imx_lcdc_pipe_enable,
-	.disable = imx_lcdc_pipe_disable,
-	.check = imx_lcdc_pipe_check,
-	.update = imx_lcdc_pipe_update,
+static void imx_lcdc_crtc_disable_vblank(struct drm_crtc *crtc)
+{
+}
+
+static const struct drm_crtc_funcs imx_lcdc_crtc_funcs = {
+	.atomic_create_state	= drm_atomic_helper_crtc_create_state,
+	.destroy		= drm_crtc_cleanup,
+	.set_config		= drm_atomic_helper_set_config,
+	.page_flip		= drm_atomic_helper_page_flip,
+	.atomic_duplicate_state	= drm_atomic_helper_crtc_duplicate_state,
+	.atomic_destroy_state	= drm_atomic_helper_crtc_destroy_state,
+	.enable_vblank		= imx_lcdc_crtc_enable_vblank,
+	.disable_vblank		= imx_lcdc_crtc_disable_vblank,
+};
+
+static const struct drm_encoder_funcs imx_lcdc_encoder_funcs = {
+	.destroy = drm_encoder_cleanup,
 };
 
 static const struct drm_mode_config_funcs imx_lcdc_mode_config_funcs = {
@@ -369,7 +447,7 @@ MODULE_DEVICE_TABLE(of, imx_lcdc_of_dev_id);
 static irqreturn_t imx_lcdc_irq_handler(int irq, void *arg)
 {
 	struct imx_lcdc *lcdc = arg;
-	struct drm_crtc *crtc = &lcdc->pipe.crtc;
+	struct drm_crtc *crtc = &lcdc->crtc;
 	unsigned int status;
 
 	status = readl(lcdc->base + IMX21LCDC_LISR);
@@ -387,6 +465,9 @@ static int imx_lcdc_probe(struct platform_device *pdev)
 	struct imx_lcdc *lcdc;
 	struct drm_device *drm;
 	struct drm_bridge *bridge;
+	struct drm_plane *plane;
+	struct drm_crtc *crtc;
+	struct drm_encoder *encoder;
 	int irq;
 	int ret;
 	struct device *dev = &pdev->dev;
@@ -428,23 +509,40 @@ static int imx_lcdc_probe(struct platform_device *pdev)
 	if (ret)
 		return dev_err_probe(dev, ret, "Cannot initialize mode configuration structure\n");
 
-	/* CRTC, Plane, Encoder */
-	ret = drm_simple_display_pipe_init(drm, &lcdc->pipe,
-					   &imx_lcdc_pipe_funcs,
-					   imx_lcdc_formats,
-					   ARRAY_SIZE(imx_lcdc_formats), NULL, NULL);
+	plane = &lcdc->plane;
+	ret = drm_universal_plane_init(drm, plane, 0,
+				       &imx_lcdc_plane_funcs,
+				       imx_lcdc_formats,
+				       ARRAY_SIZE(imx_lcdc_formats),
+				       NULL,
+				       DRM_PLANE_TYPE_PRIMARY, NULL);
+	if (ret < 0)
+		return dev_err_probe(drm->dev, ret, "Cannot initialize primary plane\n");
+	drm_plane_helper_add(plane, &imx_lcdc_plane_helper_funcs);
+
+	crtc = &lcdc->crtc;
+	ret = drm_crtc_init_with_planes(drm, crtc, plane, NULL,
+					&imx_lcdc_crtc_funcs, NULL);
+	if (ret < 0)
+		return dev_err_probe(drm->dev, ret, "Cannot initialize CRTC\n");
+	drm_crtc_helper_add(crtc, &imx_lcdc_crtc_helper_funcs);
+
+	encoder = &lcdc->encoder;
+	ret = drm_encoder_init(drm, encoder, &imx_lcdc_encoder_funcs,
+			       DRM_MODE_ENCODER_NONE, NULL);
 	if (ret < 0)
-		return dev_err_probe(drm->dev, ret, "Cannot setup simple display pipe\n");
+		return dev_err_probe(drm->dev, ret, "Cannot initialize encoder\n");
+	encoder->possible_crtcs = drm_crtc_mask(crtc);
 
 	ret = drm_vblank_init(drm, drm->mode_config.num_crtc);
 	if (ret < 0)
 		return dev_err_probe(drm->dev, ret, "Failed to initialize vblank\n");
 
-	ret = drm_bridge_attach(&lcdc->pipe.encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+	ret = drm_bridge_attach(encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
 	if (ret)
 		return dev_err_probe(drm->dev, ret, "Cannot attach bridge\n");
 
-	lcdc->connector = drm_bridge_connector_init(drm, &lcdc->pipe.encoder);
+	lcdc->connector = drm_bridge_connector_init(drm, encoder);
 	if (IS_ERR(lcdc->connector))
 		return dev_err_probe(drm->dev, PTR_ERR(lcdc->connector), "Cannot init bridge connector\n");
 
@@ -483,7 +581,9 @@ static int imx_lcdc_probe(struct platform_device *pdev)
 	drm->mode_config.funcs = &imx_lcdc_mode_config_funcs;
 	drm->mode_config.helper_private = &imx_lcdc_mode_config_helpers;
 
-	drm_mode_config_reset(drm);
+	ret = drm_mode_config_create_initial_state(drm);
+	if (ret)
+		return dev_err_probe(dev, ret, "Cannot create initial state\n");
 
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0) {

-- 
2.55.0

Re: [PATCH v4 2/2] drm/imx: replace struct drm_simple_display_pipe with regular atomic helpers

[Thomas Zimmermann]

Hi

Am 19.09.26 um 16:59 schrieb Ze Huang:
> Convert i.MX LCDC to explicit primary plane, CRTC and encoder objects.
> Keep no-scaling plane check and GEM framebuffer prepare callback from
> simple-KMS path.
>
> Wire the vblank lifecycle explicitly with CRTC vblank callbacks and
> drm_crtc_vblank_on()/drm_crtc_vblank_off(). Use the old CRTC state in
> the disable path for clock unwinding so the clock reference count
> remains paired with the previous active state.
>
> Use the atomic_create_state helpers with
> drm_mode_config_create_initial_state() in probe, and
> drm_crtc_vblank_atomic_flush() for the flush callback.
>
> Signed-off-by: Ze Huang <ze.huang@oss.qualcomm.com>

IDK how well (or if) this driver is still maintained. I'd give it the 
benefit of the doubt to make progress with the DRM cleanup. If there's a 
bug in this patch, users will report it quickly.

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>

Best regards
Thomas


> ---
>   drivers/gpu/drm/imx/lcdc/imx-lcdc.c | 250 +++++++++++++++++++++++++-----------
>   1 file changed, 175 insertions(+), 75 deletions(-)
>
> diff --git a/drivers/gpu/drm/imx/lcdc/imx-lcdc.c b/drivers/gpu/drm/imx/lcdc/imx-lcdc.c
> index e00e52c1c46e..8f0a0d4cf61a 100644
> --- a/drivers/gpu/drm/imx/lcdc/imx-lcdc.c
> +++ b/drivers/gpu/drm/imx/lcdc/imx-lcdc.c
> @@ -2,6 +2,7 @@
>   // SPDX-FileCopyrightText: 2020 Marian Cichy <M.Cichy@pengutronix.de>
>   
>   #include <drm/clients/drm_client_setup.h>
> +#include <drm/drm_atomic.h>
>   #include <drm/drm_bridge.h>
>   #include <drm/drm_bridge_connector.h>
>   #include <drm/drm_damage_helper.h>
> @@ -14,10 +15,11 @@
>   #include <drm/drm_gem_dma_helper.h>
>   #include <drm/drm_gem_framebuffer_helper.h>
>   #include <drm/drm_of.h>
> +#include <drm/drm_plane_helper.h>
>   #include <drm/drm_print.h>
>   #include <drm/drm_probe_helper.h>
> -#include <drm/drm_simple_kms_helper.h>
>   #include <drm/drm_vblank.h>
> +#include <drm/drm_vblank_helper.h>
>   #include <linux/bitfield.h>
>   #include <linux/clk.h>
>   #include <linux/dma-mapping.h>
> @@ -101,7 +103,9 @@
>   
>   struct imx_lcdc {
>   	struct drm_device drm;
> -	struct drm_simple_display_pipe pipe;
> +	struct drm_plane plane;
> +	struct drm_crtc crtc;
> +	struct drm_encoder encoder;
>   	struct drm_connector *connector;
>   	void __iomem *base;
>   
> @@ -134,14 +138,15 @@ static unsigned int imx_lcdc_get_format(unsigned int drm_format)
>   	}
>   }
>   
> -static void imx_lcdc_update_hw_registers(struct drm_simple_display_pipe *pipe,
> -					 struct drm_plane_state *old_state,
> +static void imx_lcdc_update_hw_registers(struct drm_crtc *crtc,
> +					 struct drm_crtc_state *old_crtc_state,
> +					 struct drm_crtc_state *new_crtc_state,
> +					 struct drm_plane_state *new_state,
>   					 bool mode_set)
>   {
> -	struct drm_crtc *crtc = &pipe->crtc;
> -	struct drm_plane_state *new_state = pipe->plane.state;
> +	struct imx_lcdc *lcdc = imx_lcdc_from_drmdev(crtc->dev);
> +	const struct drm_display_mode *mode = &new_crtc_state->mode;
>   	struct drm_framebuffer *fb = new_state->fb;
> -	struct imx_lcdc *lcdc = imx_lcdc_from_drmdev(pipe->crtc.dev);
>   	u32 lpcr, lvcr, lhcr;
>   	u32 framesize;
>   	dma_addr_t addr;
> @@ -154,24 +159,24 @@ static void imx_lcdc_update_hw_registers(struct drm_simple_display_pipe *pipe,
>   		return;
>   
>   	/* Disable PER clock to make register write possible */
> -	if (old_state && old_state->crtc && old_state->crtc->enabled)
> +	if (old_crtc_state && old_crtc_state->enable)
>   		clk_disable_unprepare(lcdc->clk_per);
>   
>   	/* Framesize */
> -	framesize = FIELD_PREP(IMX21LCDC_LSR_XMAX, crtc->mode.hdisplay >> 4) |
> -		FIELD_PREP(IMX21LCDC_LSR_YMAX, crtc->mode.vdisplay);
> +	framesize = FIELD_PREP(IMX21LCDC_LSR_XMAX, mode->hdisplay >> 4) |
> +		FIELD_PREP(IMX21LCDC_LSR_YMAX, mode->vdisplay);
>   	writel(framesize, lcdc->base + IMX21LCDC_LSR);
>   
>   	/* HSYNC */
> -	lhcr = FIELD_PREP(IMX21LCDC_LHCR_HFPORCH, crtc->mode.hsync_start - crtc->mode.hdisplay - 1) |
> -		FIELD_PREP(IMX21LCDC_LHCR_HWIDTH, crtc->mode.hsync_end - crtc->mode.hsync_start - 1) |
> -		FIELD_PREP(IMX21LCDC_LHCR_HBPORCH, crtc->mode.htotal - crtc->mode.hsync_end - 3);
> +	lhcr = FIELD_PREP(IMX21LCDC_LHCR_HFPORCH, mode->hsync_start - mode->hdisplay - 1) |
> +		FIELD_PREP(IMX21LCDC_LHCR_HWIDTH, mode->hsync_end - mode->hsync_start - 1) |
> +		FIELD_PREP(IMX21LCDC_LHCR_HBPORCH, mode->htotal - mode->hsync_end - 3);
>   	writel(lhcr, lcdc->base + IMX21LCDC_LHCR);
>   
>   	/* VSYNC */
> -	lvcr = FIELD_PREP(IMX21LCDC_LVCR_VFPORCH, crtc->mode.vsync_start - crtc->mode.vdisplay) |
> -		FIELD_PREP(IMX21LCDC_LVCR_VWIDTH, crtc->mode.vsync_end - crtc->mode.vsync_start) |
> -		FIELD_PREP(IMX21LCDC_LVCR_VBPORCH, crtc->mode.vtotal - crtc->mode.vsync_end);
> +	lvcr = FIELD_PREP(IMX21LCDC_LVCR_VFPORCH, mode->vsync_start - mode->vdisplay) |
> +		FIELD_PREP(IMX21LCDC_LVCR_VWIDTH, mode->vsync_end - mode->vsync_start) |
> +		FIELD_PREP(IMX21LCDC_LVCR_VBPORCH, mode->vtotal - mode->vsync_end);
>   	writel(lvcr, lcdc->base + IMX21LCDC_LVCR);
>   
>   	lpcr = readl(lcdc->base + IMX21LCDC_LPCR);
> @@ -183,19 +188,20 @@ static void imx_lcdc_update_hw_registers(struct drm_simple_display_pipe *pipe,
>   	writel(new_state->fb->pitches[0] / 4, lcdc->base + IMX21LCDC_LVPWR);
>   
>   	/* Enable PER clock */
> -	if (new_state->crtc->enabled)
> +	if (new_crtc_state->enable)
>   		clk_prepare_enable(lcdc->clk_per);
>   }
>   
> -static void imx_lcdc_pipe_enable(struct drm_simple_display_pipe *pipe,
> -				 struct drm_crtc_state *crtc_state,
> -				 struct drm_plane_state *plane_state)
> +static void imx_lcdc_crtc_helper_atomic_enable(struct drm_crtc *crtc,
> +					       struct drm_atomic_commit *commit)
>   {
>   	int ret;
>   	int clk_div;
>   	int bpp;
> -	struct imx_lcdc *lcdc = imx_lcdc_from_drmdev(pipe->crtc.dev);
> -	struct drm_display_mode *mode = &pipe->crtc.mode;
> +	struct imx_lcdc *lcdc = imx_lcdc_from_drmdev(crtc->dev);
> +	struct drm_crtc_state *cstate = drm_atomic_get_new_crtc_state(commit, crtc);
> +	struct drm_plane_state *pstate = drm_atomic_get_new_plane_state(commit, &lcdc->plane);
> +	struct drm_display_mode *mode = &cstate->mode;
>   	struct drm_display_info *disp_info = &lcdc->connector->display_info;
>   	const int hsync_pol = (mode->flags & DRM_MODE_FLAG_PHSYNC) ? 0 : 1;
>   	const int vsync_pol = (mode->flags & DRM_MODE_FLAG_PVSYNC) ? 0 : 1;
> @@ -206,7 +212,7 @@ static void imx_lcdc_pipe_enable(struct drm_simple_display_pipe *pipe,
>   
>   	clk_div = DIV_ROUND_CLOSEST_ULL(clk_get_rate(lcdc->clk_per),
>   					mode->clock * 1000);
> -	bpp = imx_lcdc_get_format(plane_state->fb->format->format);
> +	bpp = imx_lcdc_get_format(pstate->fb->format->format);
>   
>   	writel(FIELD_PREP(IMX21LCDC_LPCR_PCD, clk_div - 1) |
>   	       FIELD_PREP(IMX21LCDC_LPCR_LPPOL, hsync_pol) |
> @@ -230,40 +236,46 @@ static void imx_lcdc_pipe_enable(struct drm_simple_display_pipe *pipe,
>   
>   	ret = clk_prepare_enable(lcdc->clk_ipg);
>   	if (ret) {
> -		dev_err(pipe->crtc.dev->dev, "Cannot enable ipg clock: %pe\n", ERR_PTR(ret));
> +		dev_err(crtc->dev->dev, "Cannot enable ipg clock: %pe\n", ERR_PTR(ret));
>   		return;
>   	}
>   	ret = clk_prepare_enable(lcdc->clk_ahb);
>   	if (ret) {
> -		dev_err(pipe->crtc.dev->dev, "Cannot enable ahb clock: %pe\n", ERR_PTR(ret));
> +		dev_err(crtc->dev->dev, "Cannot enable ahb clock: %pe\n", ERR_PTR(ret));
>   
>   		clk_disable_unprepare(lcdc->clk_ipg);
>   
>   		return;
>   	}
>   
> -	imx_lcdc_update_hw_registers(pipe, NULL, true);
> +	imx_lcdc_update_hw_registers(crtc, NULL, cstate, pstate, true);
>   
>   	/* Enable VBLANK Interrupt */
>   	writel(INTR_EOF, lcdc->base + IMX21LCDC_LIER);
> +
> +	drm_crtc_vblank_on(crtc);
>   }
>   
> -static void imx_lcdc_pipe_disable(struct drm_simple_display_pipe *pipe)
> +static void imx_lcdc_crtc_helper_atomic_disable(struct drm_crtc *crtc,
> +						struct drm_atomic_commit *commit)
>   {
> -	struct imx_lcdc *lcdc = imx_lcdc_from_drmdev(pipe->crtc.dev);
> -	struct drm_crtc *crtc = &lcdc->pipe.crtc;
> +	struct drm_crtc_state *old_crtc_state = drm_atomic_get_old_crtc_state(commit, crtc);
> +	struct drm_crtc_state *new_crtc_state = drm_atomic_get_new_crtc_state(commit, crtc);
> +	struct imx_lcdc *lcdc = imx_lcdc_from_drmdev(crtc->dev);
>   	struct drm_pending_vblank_event *event;
>   
> +	drm_crtc_vblank_off(crtc);
> +
>   	clk_disable_unprepare(lcdc->clk_ahb);
>   	clk_disable_unprepare(lcdc->clk_ipg);
>   
> -	if (pipe->crtc.enabled)
> +	if (old_crtc_state->enable)
>   		clk_disable_unprepare(lcdc->clk_per);
>   
>   	spin_lock_irq(&lcdc->drm.event_lock);
> -	event = crtc->state->event;
> +	event = new_crtc_state->event;
>   	if (event) {
> -		crtc->state->event = NULL;
> +		new_crtc_state->event = NULL;
>   		drm_crtc_send_vblank_event(crtc, event);
>   	}
>   	spin_unlock_irq(&lcdc->drm.event_lock);
> @@ -272,66 +284,132 @@ static void imx_lcdc_pipe_disable(struct drm_simple_display_pipe *pipe)
>   	writel(0, lcdc->base + IMX21LCDC_LIER);
>   }
>   
> -static int imx_lcdc_pipe_check(struct drm_simple_display_pipe *pipe,
> -			       struct drm_plane_state *plane_state,
> -			       struct drm_crtc_state *crtc_state)
> +static int imx_lcdc_crtc_helper_atomic_check(struct drm_crtc *crtc,
> +					     struct drm_atomic_commit *commit)
>   {
> +	struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(commit, crtc);
> +	struct drm_crtc_state *old_crtc_state = drm_atomic_get_old_crtc_state(commit, crtc);
>   	const struct drm_display_mode *mode = &crtc_state->mode;
> -	const struct drm_display_mode *old_mode = &pipe->crtc.state->mode;
> +	const struct drm_display_mode *old_mode = &old_crtc_state->mode;
> +	int ret;
> +
> +	if (crtc_state->enable) {
> +		ret = drm_atomic_helper_check_crtc_primary_plane(crtc_state);
> +		if (ret)
> +			return ret;
> +	}
>   
> -	if (mode->hdisplay < LCDC_MIN_XRES || mode->hdisplay > LCDC_MAX_XRES ||
> -	    mode->vdisplay < LCDC_MIN_YRES || mode->vdisplay > LCDC_MAX_YRES ||
> -	    mode->hdisplay % 0x10) { /* must be multiple of 16 */
> -		drm_err(pipe->crtc.dev, "unsupported display mode (%u x %u)\n",
> +	if (crtc_state->enable &&
> +	    (mode->hdisplay < LCDC_MIN_XRES || mode->hdisplay > LCDC_MAX_XRES ||
> +	     mode->vdisplay < LCDC_MIN_YRES || mode->vdisplay > LCDC_MAX_YRES ||
> +	     mode->hdisplay % 0x10)) { /* must be multiple of 16 */
> +		drm_err(crtc->dev, "unsupported display mode (%u x %u)\n",
>   			mode->hdisplay, mode->vdisplay);
>   		return -EINVAL;
>   	}
>   
> -	crtc_state->mode_changed =
> -		old_mode->hdisplay != mode->hdisplay ||
> -		old_mode->vdisplay != mode->vdisplay;
> +	if (old_mode->hdisplay != mode->hdisplay ||
> +	    old_mode->vdisplay != mode->vdisplay)
> +		crtc_state->mode_changed = true;
>   
> -	return 0;
> +	return drm_atomic_add_affected_planes(commit, crtc);
>   }
>   
> -static void imx_lcdc_pipe_update(struct drm_simple_display_pipe *pipe,
> -				 struct drm_plane_state *old_state)
> +static void imx_lcdc_plane_helper_atomic_update(struct drm_plane *plane,
> +						struct drm_atomic_commit *commit)
>   {
> -	struct drm_crtc *crtc = &pipe->crtc;
> -	struct drm_pending_vblank_event *event = crtc->state->event;
> -	struct drm_plane_state *new_state = pipe->plane.state;
> +	struct drm_plane_state *old_state = drm_atomic_get_old_plane_state(commit, plane);
> +	struct drm_plane_state *new_state = drm_atomic_get_new_plane_state(commit, plane);
> +	struct drm_crtc *crtc = new_state->crtc;
> +	struct drm_crtc_state *old_crtc_state = NULL;
> +	struct drm_crtc_state *new_crtc_state;
>   	struct drm_framebuffer *fb = new_state->fb;
>   	struct drm_framebuffer *old_fb = old_state->fb;
>   	struct drm_crtc *old_crtc = old_state->crtc;
>   	bool mode_changed = false;
>   
> +	if (!fb || !crtc)
> +		return;
> +
> +	if (old_crtc)
> +		old_crtc_state = drm_atomic_get_old_crtc_state(commit, old_crtc);
> +
> +	new_crtc_state = drm_atomic_get_new_crtc_state(commit, crtc);
> +	if (!new_crtc_state)
> +		return;
> +
>   	if (old_fb && old_fb->format != fb->format)
>   		mode_changed = true;
>   	else if (old_crtc != crtc)
>   		mode_changed = true;
>   
> -	if (!drm_atomic_crtc_needs_modeset(crtc->state))
> -		imx_lcdc_update_hw_registers(pipe, old_state, mode_changed);
> +	if (!drm_atomic_crtc_needs_modeset(new_crtc_state))
> +		imx_lcdc_update_hw_registers(crtc, old_crtc_state, new_crtc_state,
> +					     new_state, mode_changed);
> +}
>   
> -	if (event) {
> -		crtc->state->event = NULL;
> +static int imx_lcdc_plane_helper_atomic_check(struct drm_plane *plane,
> +					      struct drm_atomic_commit *commit)
> +{
> +	struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(commit, plane);
> +	struct drm_crtc_state *crtc_state = NULL;
>   
> -		spin_lock_irq(&crtc->dev->event_lock);
> +	if (plane_state->crtc) {
> +		crtc_state = drm_atomic_get_crtc_state(commit, plane_state->crtc);
> +		if (IS_ERR(crtc_state))
> +			return PTR_ERR(crtc_state);
> +	}
>   
> -		if (crtc->state->active && drm_crtc_vblank_get(crtc) == 0)
> -			drm_crtc_arm_vblank_event(crtc, event);
> -		else
> -			drm_crtc_send_vblank_event(crtc, event);
> +	return drm_atomic_helper_check_plane_state(plane_state, crtc_state,
> +						   DRM_PLANE_NO_SCALING,
> +						   DRM_PLANE_NO_SCALING,
> +						   false, false);
> +}
>   
> -		spin_unlock_irq(&crtc->dev->event_lock);
> -	}
> +static const struct drm_plane_helper_funcs imx_lcdc_plane_helper_funcs = {
> +	.prepare_fb	= drm_gem_plane_helper_prepare_fb,
> +	.atomic_check	= imx_lcdc_plane_helper_atomic_check,
> +	.atomic_update	= imx_lcdc_plane_helper_atomic_update,
> +};
> +
> +static const struct drm_plane_funcs imx_lcdc_plane_funcs = {
> +	.update_plane		= drm_atomic_helper_update_plane,
> +	.disable_plane		= drm_atomic_helper_disable_plane,
> +	.destroy		= drm_plane_cleanup,
> +	.atomic_create_state	= drm_atomic_helper_plane_create_state,
> +	.atomic_duplicate_state	= drm_atomic_helper_plane_duplicate_state,
> +	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
> +};
> +
> +static const struct drm_crtc_helper_funcs imx_lcdc_crtc_helper_funcs = {
> +	.atomic_check	= imx_lcdc_crtc_helper_atomic_check,
> +	.atomic_enable	= imx_lcdc_crtc_helper_atomic_enable,
> +	.atomic_disable	= imx_lcdc_crtc_helper_atomic_disable,
> +	.atomic_flush	= drm_crtc_vblank_atomic_flush,
> +};
> +
> +static int imx_lcdc_crtc_enable_vblank(struct drm_crtc *crtc)
> +{
> +	return 0;
>   }
>   
> -static const struct drm_simple_display_pipe_funcs imx_lcdc_pipe_funcs = {
> -	.enable = imx_lcdc_pipe_enable,
> -	.disable = imx_lcdc_pipe_disable,
> -	.check = imx_lcdc_pipe_check,
> -	.update = imx_lcdc_pipe_update,
> +static void imx_lcdc_crtc_disable_vblank(struct drm_crtc *crtc)
> +{
> +}
> +
> +static const struct drm_crtc_funcs imx_lcdc_crtc_funcs = {
> +	.atomic_create_state	= drm_atomic_helper_crtc_create_state,
> +	.destroy		= drm_crtc_cleanup,
> +	.set_config		= drm_atomic_helper_set_config,
> +	.page_flip		= drm_atomic_helper_page_flip,
> +	.atomic_duplicate_state	= drm_atomic_helper_crtc_duplicate_state,
> +	.atomic_destroy_state	= drm_atomic_helper_crtc_destroy_state,
> +	.enable_vblank		= imx_lcdc_crtc_enable_vblank,
> +	.disable_vblank		= imx_lcdc_crtc_disable_vblank,
> +};
> +
> +static const struct drm_encoder_funcs imx_lcdc_encoder_funcs = {
> +	.destroy = drm_encoder_cleanup,
>   };
>   
>   static const struct drm_mode_config_funcs imx_lcdc_mode_config_funcs = {
> @@ -369,7 +447,7 @@ MODULE_DEVICE_TABLE(of, imx_lcdc_of_dev_id);
>   static irqreturn_t imx_lcdc_irq_handler(int irq, void *arg)
>   {
>   	struct imx_lcdc *lcdc = arg;
> -	struct drm_crtc *crtc = &lcdc->pipe.crtc;
> +	struct drm_crtc *crtc = &lcdc->crtc;
>   	unsigned int status;
>   
>   	status = readl(lcdc->base + IMX21LCDC_LISR);
> @@ -387,6 +465,9 @@ static int imx_lcdc_probe(struct platform_device *pdev)
>   	struct imx_lcdc *lcdc;
>   	struct drm_device *drm;
>   	struct drm_bridge *bridge;
> +	struct drm_plane *plane;
> +	struct drm_crtc *crtc;
> +	struct drm_encoder *encoder;
>   	int irq;
>   	int ret;
>   	struct device *dev = &pdev->dev;
> @@ -428,23 +509,40 @@ static int imx_lcdc_probe(struct platform_device *pdev)
>   	if (ret)
>   		return dev_err_probe(dev, ret, "Cannot initialize mode configuration structure\n");
>   
> -	/* CRTC, Plane, Encoder */
> -	ret = drm_simple_display_pipe_init(drm, &lcdc->pipe,
> -					   &imx_lcdc_pipe_funcs,
> -					   imx_lcdc_formats,
> -					   ARRAY_SIZE(imx_lcdc_formats), NULL, NULL);
> +	plane = &lcdc->plane;
> +	ret = drm_universal_plane_init(drm, plane, 0,
> +				       &imx_lcdc_plane_funcs,
> +				       imx_lcdc_formats,
> +				       ARRAY_SIZE(imx_lcdc_formats),
> +				       NULL,
> +				       DRM_PLANE_TYPE_PRIMARY, NULL);
> +	if (ret < 0)
> +		return dev_err_probe(drm->dev, ret, "Cannot initialize primary plane\n");
> +	drm_plane_helper_add(plane, &imx_lcdc_plane_helper_funcs);
> +
> +	crtc = &lcdc->crtc;
> +	ret = drm_crtc_init_with_planes(drm, crtc, plane, NULL,
> +					&imx_lcdc_crtc_funcs, NULL);
> +	if (ret < 0)
> +		return dev_err_probe(drm->dev, ret, "Cannot initialize CRTC\n");
> +	drm_crtc_helper_add(crtc, &imx_lcdc_crtc_helper_funcs);
> +
> +	encoder = &lcdc->encoder;
> +	ret = drm_encoder_init(drm, encoder, &imx_lcdc_encoder_funcs,
> +			       DRM_MODE_ENCODER_NONE, NULL);
>   	if (ret < 0)
> -		return dev_err_probe(drm->dev, ret, "Cannot setup simple display pipe\n");
> +		return dev_err_probe(drm->dev, ret, "Cannot initialize encoder\n");
> +	encoder->possible_crtcs = drm_crtc_mask(crtc);
>   
>   	ret = drm_vblank_init(drm, drm->mode_config.num_crtc);
>   	if (ret < 0)
>   		return dev_err_probe(drm->dev, ret, "Failed to initialize vblank\n");
>   
> -	ret = drm_bridge_attach(&lcdc->pipe.encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> +	ret = drm_bridge_attach(encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
>   	if (ret)
>   		return dev_err_probe(drm->dev, ret, "Cannot attach bridge\n");
>   
> -	lcdc->connector = drm_bridge_connector_init(drm, &lcdc->pipe.encoder);
> +	lcdc->connector = drm_bridge_connector_init(drm, encoder);
>   	if (IS_ERR(lcdc->connector))
>   		return dev_err_probe(drm->dev, PTR_ERR(lcdc->connector), "Cannot init bridge connector\n");
>   
> @@ -483,7 +581,9 @@ static int imx_lcdc_probe(struct platform_device *pdev)
>   	drm->mode_config.funcs = &imx_lcdc_mode_config_funcs;
>   	drm->mode_config.helper_private = &imx_lcdc_mode_config_helpers;
>   
> -	drm_mode_config_reset(drm);
> +	ret = drm_mode_config_create_initial_state(drm);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "Cannot create initial state\n");
>   
>   	irq = platform_get_irq(pdev, 0);
>   	if (irq < 0) {
>

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, (HRB 36809, AG Nürnberg)

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

[Thomas Zimmermann]

Merged into drm-misc-next

Am 19.09.26 um 16:59 schrieb 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@oss.qualcomm.com>
> ---
> 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@oss.qualcomm.com/
>
> 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@oss.qualcomm.com/
>
> 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@oss.qualcomm.com
>
> To: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> To: Maxime Ripard <mripard@kernel.org>
> To: Thomas Zimmermann <tzimmermann@suse.de>
> To: David Airlie <airlied@gmail.com>
> To: Simona Vetter <simona@ffwll.ch>
> To: Frank Li <Frank.Li@nxp.com>
> To: Sascha Hauer <s.hauer@pengutronix.de>
> To: Pengutronix Kernel Team <kernel@pengutronix.de>
> To: Fabio Estevam <festevam@gmail.com>
> To: Philipp Zabel <p.zabel@pengutronix.de>
> To: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> To: Marian Cichy <m.cichy@pengutronix.de>
> Cc: dri-devel@lists.freedesktop.org
> Cc: imx@lists.linux.dev
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-kernel@vger.kernel.org
>
> ---
> 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@oss.qualcomm.com>
>

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Stefan Gaiser, Jochen Jaser, Abhinav Puri, (HRB 36809, AG Nürnberg)