Re: [PATCH v2 09/16] drm/imx: Add i.MX8qxp Display Controller KMS

[Dmitry Baryshkov]

On Fri, Jul 12, 2024 at 05:32:36PM GMT, Liu Ying wrote:
> i.MX8qxp Display Controller(DC) is comprised of three main components that
> include a blit engine for 2D graphics accelerations, display controller for
> display output processing, as well as a command sequencer.  Add kernel
> mode setting support for the display controller part with two CRTCs and
> two primary planes(backed by FetchLayer and FetchWarp respectively).  The
> registers of the display controller are accessed without command sequencer
> involved, instead just by using CPU.  The command sequencer is supposed to
> be used by the blit engine.

Generic comment: please consider moving dc_plane / dc_crtc defines to
the source files and dropping the headers.

> 
> Signed-off-by: Liu Ying <victor.liu@xxxxxxx>
> ---
> v2:
> * Find next bridge from TCon's port.
> * Drop drm/drm_module.h include from dc-drv.c.
> 
>  drivers/gpu/drm/imx/dc/Kconfig    |   2 +
>  drivers/gpu/drm/imx/dc/Makefile   |   5 +-
>  drivers/gpu/drm/imx/dc/dc-crtc.c  | 578 ++++++++++++++++++++++++++++++
>  drivers/gpu/drm/imx/dc/dc-crtc.h  |  67 ++++
>  drivers/gpu/drm/imx/dc/dc-de.h    |   3 +
>  drivers/gpu/drm/imx/dc/dc-drv.c   | 236 ++++++++++++
>  drivers/gpu/drm/imx/dc/dc-drv.h   |  21 ++
>  drivers/gpu/drm/imx/dc/dc-kms.c   | 143 ++++++++
>  drivers/gpu/drm/imx/dc/dc-kms.h   |  15 +
>  drivers/gpu/drm/imx/dc/dc-plane.c | 227 ++++++++++++
>  drivers/gpu/drm/imx/dc/dc-plane.h |  37 ++
>  11 files changed, 1332 insertions(+), 2 deletions(-)
>  create mode 100644 drivers/gpu/drm/imx/dc/dc-crtc.c
>  create mode 100644 drivers/gpu/drm/imx/dc/dc-crtc.h
>  create mode 100644 drivers/gpu/drm/imx/dc/dc-kms.c
>  create mode 100644 drivers/gpu/drm/imx/dc/dc-kms.h
>  create mode 100644 drivers/gpu/drm/imx/dc/dc-plane.c
>  create mode 100644 drivers/gpu/drm/imx/dc/dc-plane.h
> 
> diff --git a/drivers/gpu/drm/imx/dc/Kconfig b/drivers/gpu/drm/imx/dc/Kconfig
> index b66b815fbdf1..dac0de009273 100644
> --- a/drivers/gpu/drm/imx/dc/Kconfig
> +++ b/drivers/gpu/drm/imx/dc/Kconfig
> @@ -1,6 +1,8 @@
>  config DRM_IMX8_DC
>  	tristate "Freescale i.MX8 Display Controller Graphics"
>  	depends on DRM && COMMON_CLK && OF && (ARCH_MXC || COMPILE_TEST)
> +	select DRM_GEM_DMA_HELPER
> +	select DRM_KMS_HELPER
>  	select GENERIC_IRQ_CHIP
>  	help
>  	  enable Freescale i.MX8 Display Controller(DC) graphics support
> diff --git a/drivers/gpu/drm/imx/dc/Makefile b/drivers/gpu/drm/imx/dc/Makefile
> index 1ce3e8a8db22..b9d33c074984 100644
> --- a/drivers/gpu/drm/imx/dc/Makefile
> +++ b/drivers/gpu/drm/imx/dc/Makefile
> @@ -1,6 +1,7 @@
>  # SPDX-License-Identifier: GPL-2.0
>  
> -imx8-dc-drm-objs := dc-cf.o dc-de.o dc-drv.o dc-ed.o dc-fg.o dc-fl.o dc-fu.o \
> -		    dc-fw.o dc-ic.o dc-lb.o dc-pe.o dc-tc.o
> +imx8-dc-drm-objs := dc-cf.o dc-crtc.o dc-de.o dc-drv.o dc-ed.o dc-fg.o dc-fl.o \
> +		    dc-fu.o dc-fw.o dc-ic.o dc-kms.o dc-lb.o dc-pe.o \
> +		    dc-plane.o dc-tc.o
>  
>  obj-$(CONFIG_DRM_IMX8_DC) += imx8-dc-drm.o
> diff --git a/drivers/gpu/drm/imx/dc/dc-crtc.c b/drivers/gpu/drm/imx/dc/dc-crtc.c
> new file mode 100644
> index 000000000000..e151e14a6677
> --- /dev/null
> +++ b/drivers/gpu/drm/imx/dc/dc-crtc.c
> @@ -0,0 +1,578 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright 2024 NXP
> + */
> +
> +#include <linux/completion.h>
> +#include <linux/interrupt.h>
> +#include <linux/irqreturn.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/spinlock.h>
> +
> +#include <drm/drm_atomic.h>
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_atomic_state_helper.h>
> +#include <drm/drm_crtc.h>
> +#include <drm/drm_device.h>
> +#include <drm/drm_drv.h>
> +#include <drm/drm_managed.h>
> +#include <drm/drm_modes.h>
> +#include <drm/drm_modeset_helper_vtables.h>
> +#include <drm/drm_plane.h>
> +#include <drm/drm_vblank.h>
> +
> +#include "dc-crtc.h"
> +#include "dc-de.h"
> +#include "dc-drv.h"
> +#include "dc-pe.h"
> +#include "dc-plane.h"
> +
> +#define DC_CRTC_WAIT_FOR_COMPLETION_TIMEOUT(c)				\
> +do {									\
> +	unsigned long ret;						\
> +	ret = wait_for_completion_timeout(&dc_crtc->c, HZ);		\
> +	if (ret == 0)							\
> +		dc_crtc_err(crtc, "%s: wait for " #c " timeout\n",	\
> +							__func__);	\
> +} while (0)
> +
> +#define DC_CRTC_CHECK_FRAMEGEN_FIFO(fg)					\
> +do {									\
> +	typeof(fg) _fg = (fg);						\
> +	if (dc_fg_secondary_requests_to_read_empty_fifo(_fg)) {		\
> +		dc_fg_secondary_clear_channel_status(_fg);		\
> +		dc_crtc_err(crtc, "%s: FrameGen FIFO empty\n",		\
> +							__func__);	\
> +	}								\
> +} while (0)
> +
> +#define DC_CRTC_WAIT_FOR_FRAMEGEN_SECONDARY_SYNCUP(fg)			\
> +do {									\
> +	if (dc_fg_wait_for_secondary_syncup(fg))			\
> +		dc_crtc_err(crtc,					\
> +			"%s: FrameGen secondary channel isn't syncup\n",\
> +							__func__);	\
> +} while (0)
> +
> +static u32 dc_crtc_get_vblank_counter(struct drm_crtc *crtc)
> +{
> +	struct dc_crtc *dc_crtc = to_dc_crtc(crtc);
> +
> +	return dc_fg_get_frame_index(dc_crtc->fg);
> +}
> +
> +static int dc_crtc_enable_vblank(struct drm_crtc *crtc)
> +{
> +	struct dc_crtc *dc_crtc = to_dc_crtc(crtc);
> +
> +	enable_irq(dc_crtc->irq_dec_framecomplete);
> +
> +	return 0;
> +}
> +
> +static void dc_crtc_disable_vblank(struct drm_crtc *crtc)
> +{
> +	struct dc_crtc *dc_crtc = to_dc_crtc(crtc);
> +
> +	disable_irq_nosync(dc_crtc->irq_dec_framecomplete);
> +}
> +
> +static irqreturn_t
> +dc_crtc_dec_framecomplete_irq_handler(int irq, void *dev_id)
> +{
> +	struct dc_crtc *dc_crtc = dev_id;
> +	struct drm_crtc *crtc = &dc_crtc->base;
> +	unsigned long flags;
> +
> +	drm_crtc_handle_vblank(crtc);
> +
> +	spin_lock_irqsave(&crtc->dev->event_lock, flags);
> +	if (dc_crtc->event) {
> +		drm_crtc_send_vblank_event(crtc, dc_crtc->event);
> +		dc_crtc->event = NULL;
> +		drm_crtc_vblank_put(crtc);
> +	}
> +	spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t dc_crtc_common_irq_handler(int irq, void *dev_id)
> +{
> +	struct dc_crtc *dc_crtc = dev_id;
> +	struct drm_crtc *crtc = &dc_crtc->base;
> +
> +	if (irq == dc_crtc->irq_dec_seqcomplete) {
> +		complete(&dc_crtc->dec_seqcomplete_done);
> +	} else if (irq == dc_crtc->irq_dec_shdld) {
> +		complete(&dc_crtc->dec_shdld_done);
> +	} else if (irq == dc_crtc->irq_ed_cont_shdld) {
> +		complete(&dc_crtc->ed_cont_shdld_done);
> +	} else if (irq == dc_crtc->irq_ed_safe_shdld) {
> +		complete(&dc_crtc->ed_safe_shdld_done);
> +	} else {
> +		dc_crtc_err(crtc, "invalid CRTC irq(%u)\n", irq);
> +		return IRQ_NONE;

And this is a counter-example to my previous questions. If you had 4
separate handlers, there would have been no need for the futile "invalid
CRTC" error, because it would not be possible at all.

> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static const struct drm_crtc_funcs dc_crtc_funcs = {
> +	.reset			= drm_atomic_helper_crtc_reset,
> +	.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,
> +	.get_vblank_counter	= dc_crtc_get_vblank_counter,
> +	.enable_vblank		= dc_crtc_enable_vblank,
> +	.disable_vblank		= dc_crtc_disable_vblank,
> +	.get_vblank_timestamp	= drm_crtc_vblank_helper_get_vblank_timestamp,
> +};
> +
> +static void dc_crtc_queue_state_event(struct drm_crtc_state *crtc_state)
> +{
> +	struct drm_crtc *crtc = crtc_state->crtc;
> +	struct dc_crtc *dc_crtc = to_dc_crtc(crtc);
> +
> +	spin_lock_irq(&crtc->dev->event_lock);
> +	if (crtc_state->event) {
> +		WARN_ON(drm_crtc_vblank_get(crtc));
> +		WARN_ON(dc_crtc->event);
> +		dc_crtc->event = crtc_state->event;
> +		crtc_state->event = NULL;
> +	}
> +	spin_unlock_irq(&crtc->dev->event_lock);
> +}
> +
> +static enum drm_mode_status
> +dc_crtc_check_clock(struct dc_crtc *dc_crtc, int clk_khz)
> +{
> +	return dc_fg_check_clock(dc_crtc->fg, clk_khz);
> +}
> +
> +static enum drm_mode_status
> +dc_crtc_mode_valid(struct drm_crtc *crtc, const struct drm_display_mode *mode)
> +{
> +	struct dc_crtc *dc_crtc = to_dc_crtc(crtc);
> +	enum drm_mode_status status;
> +
> +	status = dc_crtc_check_clock(dc_crtc, mode->clock);
> +	if (status != MODE_OK)
> +		return status;
> +
> +	if (mode->crtc_clock > DC_FRAMEGEN_MAX_CLOCK_KHZ)
> +		return MODE_CLOCK_HIGH;
> +
> +	return MODE_OK;
> +}
> +
> +static int
> +dc_crtc_atomic_check(struct drm_crtc *crtc, struct drm_atomic_state *state)
> +{
> +	struct drm_crtc_state *new_crtc_state =
> +				drm_atomic_get_new_crtc_state(state, crtc);
> +	struct drm_display_mode *adj = &new_crtc_state->adjusted_mode;
> +	struct dc_crtc *dc_crtc = to_dc_crtc(crtc);
> +	enum drm_mode_status status;
> +
> +	status = dc_crtc_check_clock(dc_crtc, adj->clock);
> +	if (status != MODE_OK)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +static void
> +dc_crtc_atomic_begin(struct drm_crtc *crtc, struct drm_atomic_state *state)
> +{
> +	struct drm_crtc_state *new_crtc_state =
> +				drm_atomic_get_new_crtc_state(state, crtc);
> +	struct dc_drm_device *dc_drm = to_dc_drm_device(crtc->dev);
> +	struct dc_crtc *dc_crtc = to_dc_crtc(crtc);
> +	int idx, ret;
> +
> +	if (!drm_atomic_crtc_needs_modeset(new_crtc_state) ||
> +	    !new_crtc_state->active)
> +		return;

Why? Can it be called under such conditions?

> +
> +	if (!drm_dev_enter(crtc->dev, &idx))
> +		return;

Can you please give an example of a driver using drm_dev_enter()/_exit()
in DRM callbacks?

> +
> +	/* request pixel engine power-on when CRTC starts to be active */
> +	ret = pm_runtime_resume_and_get(dc_crtc->pe->dev);

This function doesn't return an error. So if pm_runtime_resume_and_get()
didn't increment the counter, corresponding pm_runtime_put() might cause
an underflow. Instead void functions should use pm_runtime_get_sync()

Also can any of the code running afterwards result in the unclocked
exception if resume fails?

> +	if (ret)
> +		dc_crtc_err(crtc, "failed to get DC pixel engine RPM: %d\n",
> +			    ret);
> +
> +	atomic_inc(&dc_drm->pe_rpm_count);

Why do you need a separate RPM count? RPM code already has one.

> +
> +	drm_dev_exit(idx);
> +}
> +


[...]

> +
> +static int
> +dc_crtc_request_irq(struct dc_crtc *dc_crtc, struct device *dev,
> +		    unsigned int irq,
> +		    irqreturn_t (*irq_handler)(int irq, void *dev_id))
> +{
> +	int ret;
> +
> +	ret = request_irq(irq, irq_handler, IRQF_NO_AUTOEN, dev_name(dev),
> +			  dc_crtc);
> +	if (ret < 0)
> +		dev_err(dev, "failed to request irq(%u): %d\n", irq, ret);
> +
> +	return ret;
> +}
> +
> +static int dc_crtc_request_irqs(struct drm_device *drm, struct dc_crtc *dc_crtc)
> +{
> +	struct {
> +		struct device *dev;
> +		unsigned int irq;
> +		irqreturn_t (*irq_handler)(int irq, void *dev_id);
> +	} irqs[] = {
> +		{
> +			dc_crtc->de->dev,
> +			dc_crtc->irq_dec_framecomplete,
> +			dc_crtc_dec_framecomplete_irq_handler,
> +		}, {
> +			dc_crtc->de->dev,
> +			dc_crtc->irq_dec_seqcomplete,
> +			dc_crtc_common_irq_handler,
> +		}, {
> +			dc_crtc->de->dev,
> +			dc_crtc->irq_dec_shdld,
> +			dc_crtc_common_irq_handler,
> +		}, {
> +			dc_crtc->ed_cont->dev,
> +			dc_crtc->irq_ed_cont_shdld,
> +			dc_crtc_common_irq_handler,
> +		}, {
> +			dc_crtc->ed_safe->dev,
> +			dc_crtc->irq_ed_safe_shdld,
> +			dc_crtc_common_irq_handler,
> +		},
> +	};
> +	struct drm_crtc *crtc = &dc_crtc->base;
> +	int i, ret;
> +
> +	dc_crtc->irqs = drmm_kcalloc(drm, ARRAY_SIZE(irqs),
> +				     sizeof(*dc_crtc->irqs), GFP_KERNEL);

Using array would remove the necessity to call drmm_kcalloc here().

> +	if (!dc_crtc->irqs) {
> +		dev_err(drm->dev, "failed to allocate CRTC%u irqs\n",
> +			crtc->index);
> +		return -ENOMEM;
> +	}
> +
> +	for (i = 0; i < ARRAY_SIZE(irqs); i++) {
> +		struct dc_crtc_irq *irq = &dc_crtc->irqs[i];
> +
> +		ret = dc_crtc_request_irq(dc_crtc, irqs[i].dev, irqs[i].irq,
> +					  irqs[i].irq_handler);
> +		if (ret)
> +			return ret;
> +
> +		irq->dc_crtc = dc_crtc;
> +		irq->irq = irqs[i].irq;
> +
> +		ret = drmm_add_action_or_reset(drm, dc_crtc_free_irq, irq);

Can you use devm_request_irq() instead?

> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +

[...]

> +
> +static int dc_kms_init_encoder_per_crtc(struct dc_drm_device *dc_drm,
> +					int crtc_index)
> +{
> +	struct dc_crtc *dc_crtc = &dc_drm->dc_crtc[crtc_index];
> +	struct drm_device *drm = &dc_drm->base;
> +	struct drm_crtc *crtc = &dc_crtc->base;
> +	struct drm_connector *connector;
> +	struct device *dev = drm->dev;
> +	struct drm_encoder *encoder;
> +	struct device_node *remote;
> +	struct drm_bridge *bridge;
> +	int ret = 0;
> +
> +	remote = of_graph_get_remote_node(dc_crtc->de->tc->dev->of_node, 0, -1);
> +	if (!of_device_is_available(remote))
> +		goto out;
> +
> +	bridge = of_drm_find_bridge(remote);

drm_of_find_panel_or_bridge() instead.

> +	if (!bridge) {
> +		ret = -EPROBE_DEFER;
> +		dev_err_probe(dev, ret, "failed to find bridge for CRTC%u\n",
> +			      crtc->index);
> +		goto out;
> +	}
> +
> +	encoder = &dc_drm->encoder[crtc_index];
> +	ret = drm_simple_encoder_init(drm, encoder, DRM_MODE_ENCODER_NONE);
> +	if (ret) {
> +		dev_err(dev, "failed to initialize encoder for CRTC%u: %d\n",
> +			crtc->index, ret);
> +		goto out;
> +	}
> +
> +	encoder->possible_crtcs = drm_crtc_mask(crtc);
> +
> +	ret = drm_bridge_attach(encoder, bridge, NULL,
> +				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> +	if (ret) {
> +		dev_err(dev,
> +			"failed to attach bridge to encoder for CRTC%u: %d\n",
> +			crtc->index, ret);
> +		goto out;
> +	}
> +
> +	connector = drm_bridge_connector_init(drm, encoder);
> +	if (IS_ERR(connector)) {
> +		ret = PTR_ERR(connector);
> +		dev_err(dev, "failed to init bridge connector for CRTC%u: %d\n",
> +			crtc->index, ret);
> +		goto out;
> +	}
> +
> +	ret = drm_connector_attach_encoder(connector, encoder);
> +	if (ret)
> +		dev_err(dev,
> +			"failed to attach encoder to connector for CRTC%u: %d\n",
> +			crtc->index, ret);
> +
> +out:
> +	of_node_put(remote);
> +	return ret;
> +}
> +
> +int dc_kms_init(struct dc_drm_device *dc_drm)
> +{
> +	struct drm_device *drm = &dc_drm->base;
> +	int ret, i;
> +
> +	ret = drmm_mode_config_init(drm);
> +	if (ret)
> +		return ret;
> +
> +	atomic_set(&dc_drm->pe_rpm_count, 0);
> +
> +	drm->mode_config.min_width = 60;
> +	drm->mode_config.min_height = 60;
> +	drm->mode_config.max_width = 8192;
> +	drm->mode_config.max_height = 8192;
> +	drm->mode_config.funcs = &dc_drm_mode_config_funcs;
> +
> +	drm->vblank_disable_immediate = true;
> +	drm->max_vblank_count = DC_FRAMEGEN_MAX_FRAME_INDEX;
> +
> +	for (i = 0; i < DC_CRTCS; i++) {
> +		ret = dc_crtc_init(dc_drm, i);
> +		if (ret)
> +			return ret;
> +
> +		ret = dc_kms_init_encoder_per_crtc(dc_drm, i);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	ret = drm_vblank_init(drm, DC_CRTCS);
> +	if (ret) {
> +		dev_err(drm->dev, "failed to init vblank support: %d\n", ret);
> +		return ret;
> +	}
> +
> +	drm_mode_config_reset(drm);
> +
> +	drm_kms_helper_poll_init(drm);
> +
> +	return 0;
> +}
> +
> +void dc_kms_uninit(struct dc_drm_device *dc_drm)
> +{
> +	drm_kms_helper_poll_fini(&dc_drm->base);
> +}
> diff --git a/drivers/gpu/drm/imx/dc/dc-kms.h b/drivers/gpu/drm/imx/dc/dc-kms.h
> new file mode 100644
> index 000000000000..4f66b11c106a
> --- /dev/null
> +++ b/drivers/gpu/drm/imx/dc/dc-kms.h
> @@ -0,0 +1,15 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * Copyright 2024 NXP
> + */
> +
> +#ifndef __DC_KMS_H__
> +#define __DC_KMS_H__
> +
> +#include "dc-de.h"
> +
> +#define DC_CRTCS	DC_DISPLAYS
> +#define DC_ENCODERS	DC_DISPLAYS
> +#define DC_PRIMARYS	DC_DISPLAYS

If they are all equal, why do you need separate defines?

> +
> +#endif /* __DC_KMS_H__ */
> diff --git a/drivers/gpu/drm/imx/dc/dc-plane.c b/drivers/gpu/drm/imx/dc/dc-plane.c
> new file mode 100644
> index 000000000000..a49b043ca167
> --- /dev/null
> +++ b/drivers/gpu/drm/imx/dc/dc-plane.c
> @@ -0,0 +1,227 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright 2024 NXP
> + */
> +
> +#include <drm/drm_atomic.h>
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_atomic_state_helper.h>
> +#include <drm/drm_crtc.h>
> +#include <drm/drm_drv.h>
> +#include <drm/drm_fb_dma_helper.h>
> +#include <drm/drm_fourcc.h>
> +#include <drm/drm_framebuffer.h>
> +#include <drm/drm_gem_atomic_helper.h>
> +#include <drm/drm_plane_helper.h>
> +
> +#include "dc-drv.h"
> +#include "dc-fu.h"
> +#include "dc-plane.h"
> +
> +#define DC_PLANE_MAX_PITCH	0x10000
> +#define DC_PLANE_MAX_PIX_CNT	8192
> +
> +static const uint32_t dc_plane_formats[] = {
> +	DRM_FORMAT_XRGB8888,
> +};
> +
> +static const struct drm_plane_funcs dc_plane_funcs = {
> +	.update_plane		= drm_atomic_helper_update_plane,
> +	.disable_plane		= drm_atomic_helper_disable_plane,
> +	.destroy		= drm_plane_cleanup,
> +	.reset			= drm_atomic_helper_plane_reset,
> +	.atomic_duplicate_state	= drm_atomic_helper_plane_duplicate_state,
> +	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
> +};
> +
> +static int dc_plane_check_no_off_screen(struct drm_plane_state *state,
> +					struct drm_crtc_state *crtc_state)
> +{
> +	if (state->dst.x1 < 0 || state->dst.y1 < 0 ||
> +	    state->dst.x2 > crtc_state->adjusted_mode.hdisplay ||
> +	    state->dst.y2 > crtc_state->adjusted_mode.vdisplay) {
> +		dc_plane_dbg(state->plane, "no off screen\n");
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int dc_plane_check_max_source_resolution(struct drm_plane_state *state)
> +{
> +	int src_h = drm_rect_height(&state->src) >> 16;
> +	int src_w = drm_rect_width(&state->src) >> 16;
> +
> +	if (src_w > DC_PLANE_MAX_PIX_CNT || src_h > DC_PLANE_MAX_PIX_CNT) {
> +		dc_plane_dbg(state->plane, "invalid source resolution\n");
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int dc_plane_check_fb(struct drm_plane_state *state)
> +{
> +	struct drm_framebuffer *fb = state->fb;
> +	dma_addr_t baseaddr = drm_fb_dma_get_gem_addr(fb, state, 0);
> +
> +	/* base address alignment */
> +	if (baseaddr & 0x3) {
> +		dc_plane_dbg(state->plane, "fb bad baddr alignment\n");
> +		return -EINVAL;
> +	}
> +
> +	/* pitches[0] range */
> +	if (fb->pitches[0] > DC_PLANE_MAX_PITCH) {
> +		dc_plane_dbg(state->plane, "fb pitches[0] is out of range\n");
> +		return -EINVAL;
> +	}
> +
> +	/* pitches[0] alignment */
> +	if (fb->pitches[0] & 0x3) {
> +		dc_plane_dbg(state->plane, "fb bad pitches[0] alignment\n");
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int
> +dc_plane_atomic_check(struct drm_plane *plane, struct drm_atomic_state *state)
> +{
> +	struct drm_plane_state *plane_state =
> +				drm_atomic_get_new_plane_state(state, plane);
> +	struct drm_crtc_state *crtc_state;
> +	int ret;
> +
> +	/* ok to disable */
> +	if (!plane_state->fb)
> +		return 0;
> +
> +	if (!plane_state->crtc) {
> +		dc_plane_dbg(plane, "no CRTC in plane state\n");
> +		return -EINVAL;
> +	}
> +
> +	crtc_state =
> +		drm_atomic_get_existing_crtc_state(state, plane_state->crtc);
> +	if (WARN_ON(!crtc_state))
> +		return -EINVAL;
> +
> +	ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
> +						  DRM_PLANE_NO_SCALING,
> +						  DRM_PLANE_NO_SCALING,
> +						  true, false);
> +	if (ret) {
> +		dc_plane_dbg(plane, "failed to check plane state: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = dc_plane_check_no_off_screen(plane_state, crtc_state);
> +	if (ret)
> +		return ret;
> +
> +	ret = dc_plane_check_max_source_resolution(plane_state);
> +	if (ret)
> +		return ret;
> +
> +	return dc_plane_check_fb(plane_state);
> +}
> +
> +static void
> +dc_plane_atomic_update(struct drm_plane *plane, struct drm_atomic_state *state)
> +{
> +	struct drm_plane_state *new_state =
> +				drm_atomic_get_new_plane_state(state, plane);
> +	struct dc_plane *dplane = to_dc_plane(plane);
> +	struct drm_framebuffer *fb = new_state->fb;
> +	const struct dc_fu_ops *fu_ops;
> +	struct dc_lb *lb = dplane->lb;
> +	struct dc_fu *fu = dplane->fu;
> +	dma_addr_t baseaddr;
> +	int src_w, src_h;
> +	int idx;
> +
> +	if (!drm_dev_enter(plane->dev, &idx))
> +		return;
> +
> +	src_w = drm_rect_width(&new_state->src) >> 16;
> +	src_h = drm_rect_height(&new_state->src) >> 16;
> +
> +	baseaddr = drm_fb_dma_get_gem_addr(fb, new_state, 0);
> +
> +	fu_ops = dc_fu_get_ops(dplane->fu);
> +
> +	fu_ops->set_layerblend(fu, lb);
> +	fu_ops->set_burstlength(fu, baseaddr);
> +	fu_ops->set_src_stride(fu, fb->pitches[0]);
> +	fu_ops->set_src_buf_dimensions(fu, src_w, src_h);
> +	fu_ops->set_fmt(fu, fb->format);
> +	fu_ops->set_framedimensions(fu, src_w, src_h);
> +	fu_ops->set_baseaddress(fu, baseaddr);
> +	fu_ops->enable_src_buf(fu);

Are you expecting that these ops might change? Can you call the function
directly?

> +
> +	dc_plane_dbg(plane, "uses %s\n", fu_ops->get_name(fu));
> +
> +	dc_lb_pec_dynamic_prim_sel(lb, dc_cf_get_link_id(dplane->cf));
> +	dc_lb_pec_dynamic_sec_sel(lb, fu_ops->get_link_id(fu));
> +	dc_lb_mode(lb, LB_BLEND);
> +	dc_lb_blendcontrol(lb);
> +	dc_lb_position(lb, new_state->dst.x1, new_state->dst.y1);
> +	dc_lb_pec_clken(lb, CLKEN_AUTOMATIC);
> +
> +	dc_plane_dbg(plane, "uses LayerBlend%u\n", dc_lb_get_id(lb));
> +
> +	/* set ExtDst's source to LayerBlend */
> +	dc_ed_pec_src_sel(dplane->ed, dc_lb_get_link_id(lb));
> +
> +	drm_dev_exit(idx);
> +}
> +
> +static void dc_plane_atomic_disable(struct drm_plane *plane,
> +				    struct drm_atomic_state *state)
> +{
> +	struct dc_plane *dplane = to_dc_plane(plane);
> +	const struct dc_fu_ops *fu_ops;
> +	int idx;
> +
> +	if (!drm_dev_enter(plane->dev, &idx))
> +		return;
> +
> +	/* disable fetchunit in shadow */
> +	fu_ops = dc_fu_get_ops(dplane->fu);
> +	fu_ops->disable_src_buf(dplane->fu);
> +
> +	/* set ExtDst's source to ConstFrame */
> +	dc_ed_pec_src_sel(dplane->ed, dc_cf_get_link_id(dplane->cf));
> +
> +	drm_dev_exit(idx);
> +}
> +
> +static const struct drm_plane_helper_funcs dc_plane_helper_funcs = {
> +	.atomic_check = dc_plane_atomic_check,
> +	.atomic_update = dc_plane_atomic_update,
> +	.atomic_disable = dc_plane_atomic_disable,
> +};
> +
> +int dc_plane_init(struct dc_drm_device *dc_drm, struct dc_plane *dc_plane)
> +{
> +	struct drm_plane *plane = &dc_plane->base;
> +	int ret;
> +
> +	ret = drm_universal_plane_init(&dc_drm->base, plane, 0, &dc_plane_funcs,
> +				       dc_plane_formats,
> +				       ARRAY_SIZE(dc_plane_formats),
> +				       NULL, DRM_PLANE_TYPE_PRIMARY, NULL);
> +	if (ret)
> +		return ret;
> +
> +	drm_plane_helper_add(plane, &dc_plane_helper_funcs);
> +
> +	dc_plane->fu = dc_drm->pe->fu_disp[plane->index];
> +	dc_plane->cf = dc_drm->pe->cf_cont[plane->index];
> +	dc_plane->lb = dc_drm->pe->lb[plane->index];
> +	dc_plane->ed = dc_drm->pe->ed_cont[plane->index];
> +
> +	return 0;
> +}
> diff --git a/drivers/gpu/drm/imx/dc/dc-plane.h b/drivers/gpu/drm/imx/dc/dc-plane.h
> new file mode 100644
> index 000000000000..e72c3a7cb66f
> --- /dev/null
> +++ b/drivers/gpu/drm/imx/dc/dc-plane.h
> @@ -0,0 +1,37 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * Copyright 2024 NXP
> + */
> +
> +#ifndef __DC_PLANE_H__
> +#define __DC_PLANE_H__
> +
> +#include <linux/container_of.h>
> +
> +#include <drm/drm_plane.h>
> +#include <drm/drm_print.h>
> +
> +#include "dc-fu.h"
> +#include "dc-pe.h"
> +
> +#define dc_plane_dbg(plane, fmt, ...)					\
> +do {									\
> +	typeof(plane) _plane = (plane);					\
> +	drm_dbg_kms(_plane->dev, "[PLANE:%d:%s] " fmt,			\
> +		    _plane->base.id, _plane->name, ##__VA_ARGS__);	\
> +} while (0)
> +
> +struct dc_plane {
> +	struct drm_plane base;
> +	struct dc_fu *fu;
> +	struct dc_cf *cf;
> +	struct dc_lb *lb;
> +	struct dc_ed *ed;
> +};
> +
> +static inline struct dc_plane *to_dc_plane(struct drm_plane *plane)
> +{
> +	return container_of(plane, struct dc_plane, base);
> +}
> +
> +#endif /* __DC_PLANE_H__ */
> -- 
> 2.34.1
> 

-- 
With best wishes
Dmitry