drm/vc4: tests: Introduce a mocking infrastructure

In order to test the current atomic_check hooks we need to have a DRM
device that has roughly the same capabilities and layout that the actual
hardware. We'll also need a bunch of functions to create arbitrary
atomic states.

Let's create some helpers to create a device that behaves like the real
one, and some helpers to maintain the atomic state we want to check.

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Maíra Canal <mcanal@igalia.com>
Link: https://lore.kernel.org/r/20221123-rpi-kunit-tests-v3-17-4615a663a84a@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

12 files changed, 511 insertions, 13 deletions

diff --git a/drivers/gpu/drm/vc4/Kconfig b/drivers/gpu/drm/vc4/Kconfig
index 246305d17a52..f423941c028d 100644
--- a/drivers/gpu/drm/vc4/Kconfig
+++ b/drivers/gpu/drm/vc4/Kconfig
@@ -34,3 +34,19 @@ config DRM_VC4_HDMI_CEC
 	help
 	  Choose this option if you have a Broadcom VC4 GPU
 	  and want to use CEC.
+
+config DRM_VC4_KUNIT_TEST
+	bool "KUnit tests for VC4" if !KUNIT_ALL_TESTS
+	depends on DRM_VC4 && KUNIT
+	select DRM_KUNIT_TEST_HELPERS
+	default KUNIT_ALL_TESTS
+	help
+	  This builds unit tests for the VC4 DRM/KMS driver. This option is
+	  not useful for distributions or general kernels, but only for kernel
+	  developers working on the VC4 driver.
+
+	  For more information on KUnit and unit tests in general,
+	  please refer to the KUnit documentation in
+	  Documentation/dev-tools/kunit/.
+
+	  If in doubt, say "N".
diff --git a/drivers/gpu/drm/vc4/Makefile b/drivers/gpu/drm/vc4/Makefile
index d0163e18e9ca..f974a8c80e2f 100644
--- a/drivers/gpu/drm/vc4/Makefile
+++ b/drivers/gpu/drm/vc4/Makefile
@@ -25,6 +25,12 @@ vc4-y := \
 	vc4_validate.o \
 	vc4_validate_shaders.o
 
+vc4-$(CONFIG_DRM_VC4_KUNIT_TEST) += \
+	tests/vc4_mock.o \
+	tests/vc4_mock_crtc.o \
+	tests/vc4_mock_output.o \
+	tests/vc4_mock_plane.o
+
 vc4-$(CONFIG_DEBUG_FS) += vc4_debugfs.o
 
 obj-$(CONFIG_DRM_VC4)  += vc4.o
diff --git a/drivers/gpu/drm/vc4/tests/.kunitconfig b/drivers/gpu/drm/vc4/tests/.kunitconfig
new file mode 100644
index 000000000000..b503e9036c7f
--- /dev/null
+++ b/drivers/gpu/drm/vc4/tests/.kunitconfig
@@ -0,0 +1,13 @@
+CONFIG_ARCH_BCM=y
+CONFIG_ARCH_BCM2835=y
+CONFIG_BCM2835_MBOX=y
+CONFIG_KUNIT=y
+CONFIG_DRM=y
+CONFIG_DRM_VC4=y
+CONFIG_DRM_VC4_KUNIT_TEST=y
+CONFIG_MAILBOX=y
+CONFIG_RASPBERRYPI_FIRMWARE=y
+CONFIG_SND=y
+CONFIG_SND_SOC=y
+CONFIG_SOUND=y
+CONFIG_COMMON_CLK=y
diff --git a/drivers/gpu/drm/vc4/tests/vc4_mock.c b/drivers/gpu/drm/vc4/tests/vc4_mock.c
new file mode 100644
index 000000000000..a4bed26af32f
--- /dev/null
+++ b/drivers/gpu/drm/vc4/tests/vc4_mock.c
@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <drm/drm_drv.h>
+#include <drm/drm_kunit_helpers.h>
+
+#include <kunit/test.h>
+
+#include "vc4_mock.h"
+
+struct vc4_mock_output_desc {
+	enum vc4_encoder_type	vc4_encoder_type;
+	unsigned int		encoder_type;
+	unsigned int		connector_type;
+};
+
+#define VC4_MOCK_OUTPUT_DESC(_vc4_type, _etype, _ctype)					\
+	{										\
+		.vc4_encoder_type = _vc4_type,						\
+		.encoder_type = _etype,							\
+		.connector_type = _ctype,						\
+	}
+
+struct vc4_mock_pipe_desc {
+	const struct vc4_crtc_data *data;
+	const struct vc4_mock_output_desc *outputs;
+	unsigned int noutputs;
+};
+
+#define VC4_MOCK_CRTC_DESC(_data, ...)							\
+	{										\
+		.data = _data,								\
+		.outputs = (struct vc4_mock_output_desc[]) { __VA_ARGS__ },		\
+		.noutputs = sizeof((struct vc4_mock_output_desc[]) { __VA_ARGS__ }) /	\
+			     sizeof(struct vc4_mock_output_desc),			\
+	}
+
+#define VC4_MOCK_PIXELVALVE_DESC(_data, ...)						\
+	VC4_MOCK_CRTC_DESC(&(_data)->base, __VA_ARGS__)
+
+struct vc4_mock_desc {
+	const struct vc4_mock_pipe_desc *pipes;
+	unsigned int npipes;
+};
+
+#define VC4_MOCK_DESC(...)								\
+	{										\
+		.pipes = (struct vc4_mock_pipe_desc[]) { __VA_ARGS__ },			\
+		.npipes = sizeof((struct vc4_mock_pipe_desc[]) { __VA_ARGS__ }) /	\
+			     sizeof(struct vc4_mock_pipe_desc),				\
+	}
+
+static const struct vc4_mock_desc vc4_mock =
+	VC4_MOCK_DESC(
+		VC4_MOCK_CRTC_DESC(&vc4_txp_crtc_data,
+				   VC4_MOCK_OUTPUT_DESC(VC4_ENCODER_TYPE_TXP,
+							DRM_MODE_ENCODER_VIRTUAL,
+							DRM_MODE_CONNECTOR_WRITEBACK)),
+		VC4_MOCK_PIXELVALVE_DESC(&bcm2835_pv0_data,
+					 VC4_MOCK_OUTPUT_DESC(VC4_ENCODER_TYPE_DSI0,
+							      DRM_MODE_ENCODER_DSI,
+							      DRM_MODE_CONNECTOR_DSI),
+					 VC4_MOCK_OUTPUT_DESC(VC4_ENCODER_TYPE_DPI,
+							      DRM_MODE_ENCODER_DPI,
+							      DRM_MODE_CONNECTOR_DPI)),
+		VC4_MOCK_PIXELVALVE_DESC(&bcm2835_pv1_data,
+					 VC4_MOCK_OUTPUT_DESC(VC4_ENCODER_TYPE_DSI1,
+							      DRM_MODE_ENCODER_DSI,
+							      DRM_MODE_CONNECTOR_DSI)),
+		VC4_MOCK_PIXELVALVE_DESC(&bcm2835_pv2_data,
+					 VC4_MOCK_OUTPUT_DESC(VC4_ENCODER_TYPE_HDMI0,
+							      DRM_MODE_ENCODER_TMDS,
+							      DRM_MODE_CONNECTOR_HDMIA),
+					 VC4_MOCK_OUTPUT_DESC(VC4_ENCODER_TYPE_VEC,
+							      DRM_MODE_ENCODER_TVDAC,
+							      DRM_MODE_CONNECTOR_Composite)),
+);
+
+static const struct vc4_mock_desc vc5_mock =
+	VC4_MOCK_DESC(
+		VC4_MOCK_CRTC_DESC(&vc4_txp_crtc_data,
+				   VC4_MOCK_OUTPUT_DESC(VC4_ENCODER_TYPE_TXP,
+							DRM_MODE_ENCODER_VIRTUAL,
+							DRM_MODE_CONNECTOR_WRITEBACK)),
+		VC4_MOCK_PIXELVALVE_DESC(&bcm2711_pv0_data,
+					 VC4_MOCK_OUTPUT_DESC(VC4_ENCODER_TYPE_DSI0,
+							      DRM_MODE_ENCODER_DSI,
+							      DRM_MODE_CONNECTOR_DSI),
+					 VC4_MOCK_OUTPUT_DESC(VC4_ENCODER_TYPE_DPI,
+							      DRM_MODE_ENCODER_DPI,
+							      DRM_MODE_CONNECTOR_DPI)),
+		VC4_MOCK_PIXELVALVE_DESC(&bcm2711_pv1_data,
+					 VC4_MOCK_OUTPUT_DESC(VC4_ENCODER_TYPE_DSI1,
+							      DRM_MODE_ENCODER_DSI,
+							      DRM_MODE_CONNECTOR_DSI)),
+		VC4_MOCK_PIXELVALVE_DESC(&bcm2711_pv2_data,
+					 VC4_MOCK_OUTPUT_DESC(VC4_ENCODER_TYPE_HDMI0,
+							      DRM_MODE_ENCODER_TMDS,
+							      DRM_MODE_CONNECTOR_HDMIA)),
+		VC4_MOCK_PIXELVALVE_DESC(&bcm2711_pv3_data,
+					 VC4_MOCK_OUTPUT_DESC(VC4_ENCODER_TYPE_VEC,
+							      DRM_MODE_ENCODER_TVDAC,
+							      DRM_MODE_CONNECTOR_Composite)),
+		VC4_MOCK_PIXELVALVE_DESC(&bcm2711_pv4_data,
+					 VC4_MOCK_OUTPUT_DESC(VC4_ENCODER_TYPE_HDMI1,
+							      DRM_MODE_ENCODER_TMDS,
+							      DRM_MODE_CONNECTOR_HDMIA)),
+);
+
+static int __build_one_pipe(struct kunit *test, struct drm_device *drm,
+			    const struct vc4_mock_pipe_desc *pipe)
+{
+	struct vc4_dummy_plane *dummy_plane;
+	struct drm_plane *plane;
+	struct vc4_dummy_crtc *dummy_crtc;
+	struct drm_crtc *crtc;
+	unsigned int i;
+
+	dummy_plane = vc4_dummy_plane(test, drm, DRM_PLANE_TYPE_PRIMARY);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dummy_plane);
+
+	plane = &dummy_plane->plane.base;
+	dummy_crtc = vc4_mock_pv(test, drm, plane, pipe->data);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dummy_crtc);
+
+	crtc = &dummy_crtc->crtc.base;
+	for (i = 0; i < pipe->noutputs; i++) {
+		const struct vc4_mock_output_desc *mock_output = &pipe->outputs[i];
+		struct vc4_dummy_output *dummy_output;
+
+		dummy_output = vc4_dummy_output(test, drm, crtc,
+						mock_output->vc4_encoder_type,
+						mock_output->encoder_type,
+						mock_output->connector_type);
+		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dummy_output);
+	}
+
+	return 0;
+}
+
+static int __build_mock(struct kunit *test, struct drm_device *drm,
+			const struct vc4_mock_desc *mock)
+{
+	unsigned int i;
+
+	for (i = 0; i < mock->npipes; i++) {
+		const struct vc4_mock_pipe_desc *pipe = &mock->pipes[i];
+		int ret;
+
+		ret = __build_one_pipe(test, drm, pipe);
+		KUNIT_ASSERT_EQ(test, ret, 0);
+	}
+
+	return 0;
+}
+
+static struct vc4_dev *__mock_device(struct kunit *test, bool is_vc5)
+{
+	struct drm_device *drm;
+	const struct drm_driver *drv = is_vc5 ? &vc5_drm_driver : &vc4_drm_driver;
+	const struct vc4_mock_desc *desc = is_vc5 ? &vc5_mock : &vc4_mock;
+	struct vc4_dev *vc4;
+	struct device *dev;
+	int ret;
+
+	dev = drm_kunit_helper_alloc_device(test);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dev);
+
+	vc4 = drm_kunit_helper_alloc_drm_device_with_driver(test, dev,
+							    struct vc4_dev, base,
+							    drv);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, vc4);
+
+	vc4->dev = dev;
+	vc4->is_vc5 = is_vc5;
+
+	vc4->hvs = __vc4_hvs_alloc(vc4, NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, vc4->hvs);
+
+	drm = &vc4->base;
+	ret = __build_mock(test, drm, desc);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	ret = vc4_kms_load(drm);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	ret = drm_dev_register(drm, 0);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	return vc4;
+}
+
+struct vc4_dev *vc4_mock_device(struct kunit *test)
+{
+	return __mock_device(test, false);
+}
+
+struct vc4_dev *vc5_mock_device(struct kunit *test)
+{
+	return __mock_device(test, true);
+}
diff --git a/drivers/gpu/drm/vc4/tests/vc4_mock.h b/drivers/gpu/drm/vc4/tests/vc4_mock.h
new file mode 100644
index 000000000000..ace5b2e00f4a
--- /dev/null
+++ b/drivers/gpu/drm/vc4/tests/vc4_mock.h
@@ -0,0 +1,60 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef VC4_MOCK_H_
+#define VC4_MOCK_H_
+
+#include "../vc4_drv.h"
+
+static inline
+struct drm_crtc *vc4_find_crtc_for_encoder(struct kunit *test,
+					   struct drm_device *drm,
+					   struct drm_encoder *encoder)
+{
+	struct drm_crtc *crtc;
+
+	KUNIT_ASSERT_EQ(test, hweight32(encoder->possible_crtcs), 1);
+
+	drm_for_each_crtc(crtc, drm)
+		if (encoder->possible_crtcs & drm_crtc_mask(crtc))
+			return crtc;
+
+	return NULL;
+}
+
+struct vc4_dummy_plane {
+	struct vc4_plane plane;
+};
+
+struct vc4_dummy_plane *vc4_dummy_plane(struct kunit *test,
+					struct drm_device *drm,
+					enum drm_plane_type type);
+
+struct vc4_dummy_crtc {
+	struct vc4_crtc crtc;
+};
+
+struct vc4_dummy_crtc *vc4_mock_pv(struct kunit *test,
+				   struct drm_device *drm,
+				   struct drm_plane *plane,
+				   const struct vc4_crtc_data *data);
+
+struct vc4_dummy_output {
+	struct vc4_encoder encoder;
+	struct drm_connector connector;
+};
+
+struct vc4_dummy_output *vc4_dummy_output(struct kunit *test,
+					  struct drm_device *drm,
+					  struct drm_crtc *crtc,
+					  enum vc4_encoder_type vc4_encoder_type,
+					  unsigned int kms_encoder_type,
+					  unsigned int connector_type);
+
+struct vc4_dev *vc4_mock_device(struct kunit *test);
+struct vc4_dev *vc5_mock_device(struct kunit *test);
+
+int vc4_mock_atomic_add_output(struct kunit *test, struct drm_device *drm,
+			       enum vc4_encoder_type type,
+			       struct drm_atomic_state *state);
+
+#endif // VC4_MOCK_H_
diff --git a/drivers/gpu/drm/vc4/tests/vc4_mock_crtc.c b/drivers/gpu/drm/vc4/tests/vc4_mock_crtc.c
new file mode 100644
index 000000000000..5d12d7beef0e
--- /dev/null
+++ b/drivers/gpu/drm/vc4/tests/vc4_mock_crtc.c
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <drm/drm_atomic_state_helper.h>
+#include <drm/drm_modeset_helper_vtables.h>
+
+#include <kunit/test.h>
+
+#include "vc4_mock.h"
+
+static const struct drm_crtc_helper_funcs vc4_dummy_crtc_helper_funcs = {
+	.atomic_check	= vc4_crtc_atomic_check,
+};
+
+static const struct drm_crtc_funcs vc4_dummy_crtc_funcs = {
+	.atomic_destroy_state	= vc4_crtc_destroy_state,
+	.atomic_duplicate_state	= vc4_crtc_duplicate_state,
+	.reset			= vc4_crtc_reset,
+};
+
+struct vc4_dummy_crtc *vc4_mock_pv(struct kunit *test,
+				   struct drm_device *drm,
+				   struct drm_plane *plane,
+				   const struct vc4_crtc_data *data)
+{
+	struct vc4_dummy_crtc *dummy_crtc;
+	struct vc4_crtc *vc4_crtc;
+	int ret;
+
+	dummy_crtc = kunit_kzalloc(test, sizeof(*dummy_crtc), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, dummy_crtc);
+
+	vc4_crtc = &dummy_crtc->crtc;
+	ret = __vc4_crtc_init(drm, NULL,
+			      vc4_crtc, data, plane,
+			      &vc4_dummy_crtc_funcs,
+			      &vc4_dummy_crtc_helper_funcs,
+			      false);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	return dummy_crtc;
+}
diff --git a/drivers/gpu/drm/vc4/tests/vc4_mock_output.c b/drivers/gpu/drm/vc4/tests/vc4_mock_output.c
new file mode 100644
index 000000000000..cb16ab4451f7
--- /dev/null
+++ b/drivers/gpu/drm/vc4/tests/vc4_mock_output.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <drm/drm_atomic_state_helper.h>
+#include <drm/drm_atomic_uapi.h>
+#include <drm/drm_connector.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_encoder.h>
+#include <drm/drm_modeset_helper_vtables.h>
+
+#include <kunit/test.h>
+
+#include "vc4_mock.h"
+
+static const struct drm_connector_helper_funcs vc4_dummy_connector_helper_funcs = {
+};
+
+static const struct drm_connector_funcs vc4_dummy_connector_funcs = {
+	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
+	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
+	.reset			= drm_atomic_helper_connector_reset,
+};
+
+struct vc4_dummy_output *vc4_dummy_output(struct kunit *test,
+					  struct drm_device *drm,
+					  struct drm_crtc *crtc,
+					  enum vc4_encoder_type vc4_encoder_type,
+					  unsigned int kms_encoder_type,
+					  unsigned int connector_type)
+{
+	struct vc4_dummy_output *dummy_output;
+	struct drm_connector *conn;
+	struct drm_encoder *enc;
+	int ret;
+
+	dummy_output = kunit_kzalloc(test, sizeof(*dummy_output), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dummy_output);
+	dummy_output->encoder.type = vc4_encoder_type;
+
+	enc = &dummy_output->encoder.base;
+	ret = drmm_encoder_init(drm, enc,
+				NULL,
+				kms_encoder_type,
+				NULL);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+	enc->possible_crtcs = drm_crtc_mask(crtc);
+
+	conn = &dummy_output->connector;
+	ret = drmm_connector_init(drm, conn,
+				  &vc4_dummy_connector_funcs,
+				  connector_type,
+				  NULL);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	drm_connector_helper_add(conn, &vc4_dummy_connector_helper_funcs);
+	drm_connector_attach_encoder(conn, enc);
+
+	return dummy_output;
+}
+
+static const struct drm_display_mode default_mode = {
+	DRM_SIMPLE_MODE(640, 480, 64, 48)
+};
+
+int vc4_mock_atomic_add_output(struct kunit *test, struct drm_device *drm,
+			       enum vc4_encoder_type type,
+			       struct drm_atomic_state *state)
+{
+	struct vc4_dummy_output *output;
+	struct drm_connector *conn;
+	struct drm_connector_state *conn_state;
+	struct drm_encoder *encoder;
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *crtc_state;
+	int ret;
+
+	encoder = vc4_find_encoder_by_type(drm, type);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, encoder);
+
+	crtc = vc4_find_crtc_for_encoder(test, drm, encoder);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, crtc);
+
+	output = container_of(encoder, struct vc4_dummy_output, encoder.base);
+	conn = &output->connector;
+	conn_state = drm_atomic_get_connector_state(state, conn);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, conn_state);
+
+	ret = drm_atomic_set_crtc_for_connector(conn_state, crtc);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	crtc_state = drm_atomic_get_crtc_state(state, crtc);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, crtc_state);
+
+	ret = drm_atomic_set_mode_for_crtc(crtc_state, &default_mode);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	crtc_state->active = true;
+
+	return 0;
+}
diff --git a/drivers/gpu/drm/vc4/tests/vc4_mock_plane.c b/drivers/gpu/drm/vc4/tests/vc4_mock_plane.c
new file mode 100644
index 000000000000..62b18f5f41db
--- /dev/null
+++ b/drivers/gpu/drm/vc4/tests/vc4_mock_plane.c
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <drm/drm_atomic_state_helper.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_modeset_helper_vtables.h>
+#include <drm/drm_plane.h>
+
+#include <kunit/test.h>
+
+#include "vc4_mock.h"
+
+static const struct drm_plane_helper_funcs vc4_dummy_plane_helper_funcs = {
+};
+
+static const struct drm_plane_funcs vc4_dummy_plane_funcs = {
+	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
+	.atomic_duplicate_state	= drm_atomic_helper_plane_duplicate_state,
+	.reset			= drm_atomic_helper_plane_reset,
+};
+
+static const uint32_t vc4_dummy_plane_formats[] = {
+	DRM_FORMAT_XRGB8888,
+};
+
+struct vc4_dummy_plane *vc4_dummy_plane(struct kunit *test,
+					struct drm_device *drm,
+					enum drm_plane_type type)
+{
+	struct vc4_dummy_plane *dummy_plane;
+	struct drm_plane *plane;
+
+	dummy_plane = drmm_universal_plane_alloc(drm,
+						 struct vc4_dummy_plane, plane.base,
+						 0,
+						 &vc4_dummy_plane_funcs,
+						 vc4_dummy_plane_formats,
+						 ARRAY_SIZE(vc4_dummy_plane_formats),
+						 NULL,
+						 DRM_PLANE_TYPE_PRIMARY,
+						 NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dummy_plane);
+
+	plane = &dummy_plane->plane.base;
+	drm_plane_helper_add(plane, &vc4_dummy_plane_helper_funcs);
+
+	return dummy_plane;
+}
diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
index 195d2b61839d..7d1a696477ce 100644
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -675,8 +675,8 @@ void vc4_crtc_get_margins(struct drm_crtc_state *state,
 	}
 }
 
-static int vc4_crtc_atomic_check(struct drm_crtc *crtc,
-				 struct drm_atomic_state *state)
+int vc4_crtc_atomic_check(struct drm_crtc *crtc,
+			  struct drm_atomic_state *state)
 {
 	struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state,
 									  crtc);
@@ -1116,7 +1116,7 @@ static const struct drm_crtc_helper_funcs vc4_crtc_helper_funcs = {
 	.get_scanout_position = vc4_crtc_get_scanout_position,
 };
 
-static const struct vc4_pv_data bcm2835_pv0_data = {
+const struct vc4_pv_data bcm2835_pv0_data = {
 	.base = {
 		.name = "pixelvalve-0",
 		.debugfs_name = "crtc0_regs",
@@ -1131,7 +1131,7 @@ static const struct vc4_pv_data bcm2835_pv0_data = {
 	},
 };
 
-static const struct vc4_pv_data bcm2835_pv1_data = {
+const struct vc4_pv_data bcm2835_pv1_data = {
 	.base = {
 		.name = "pixelvalve-1",
 		.debugfs_name = "crtc1_regs",
@@ -1146,7 +1146,7 @@ static const struct vc4_pv_data bcm2835_pv1_data = {
 	},
 };
 
-static const struct vc4_pv_data bcm2835_pv2_data = {
+const struct vc4_pv_data bcm2835_pv2_data = {
 	.base = {
 		.name = "pixelvalve-2",
 		.debugfs_name = "crtc2_regs",
@@ -1161,7 +1161,7 @@ static const struct vc4_pv_data bcm2835_pv2_data = {
 	},
 };
 
-static const struct vc4_pv_data bcm2711_pv0_data = {
+const struct vc4_pv_data bcm2711_pv0_data = {
 	.base = {
 		.name = "pixelvalve-0",
 		.debugfs_name = "crtc0_regs",
@@ -1176,7 +1176,7 @@ static const struct vc4_pv_data bcm2711_pv0_data = {
 	},
 };
 
-static const struct vc4_pv_data bcm2711_pv1_data = {
+const struct vc4_pv_data bcm2711_pv1_data = {
 	.base = {
 		.name = "pixelvalve-1",
 		.debugfs_name = "crtc1_regs",
@@ -1191,7 +1191,7 @@ static const struct vc4_pv_data bcm2711_pv1_data = {
 	},
 };
 
-static const struct vc4_pv_data bcm2711_pv2_data = {
+const struct vc4_pv_data bcm2711_pv2_data = {
 	.base = {
 		.name = "pixelvalve-2",
 		.debugfs_name = "crtc2_regs",
@@ -1205,7 +1205,7 @@ static const struct vc4_pv_data bcm2711_pv2_data = {
 	},
 };
 
-static const struct vc4_pv_data bcm2711_pv3_data = {
+const struct vc4_pv_data bcm2711_pv3_data = {
 	.base = {
 		.name = "pixelvalve-3",
 		.debugfs_name = "crtc3_regs",
@@ -1219,7 +1219,7 @@ static const struct vc4_pv_data bcm2711_pv3_data = {
 	},
 };
 
-static const struct vc4_pv_data bcm2711_pv4_data = {
+const struct vc4_pv_data bcm2711_pv4_data = {
 	.base = {
 		.name = "pixelvalve-4",
 		.debugfs_name = "crtc4_regs",
diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c
index 5990d8f8c363..3b0ae2c3e33c 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.c
+++ b/drivers/gpu/drm/vc4/vc4_drv.c
@@ -196,7 +196,7 @@ static const struct drm_ioctl_desc vc4_drm_ioctls[] = {
 	DRM_IOCTL_DEF_DRV(VC4_PERFMON_GET_VALUES, vc4_perfmon_get_values_ioctl, DRM_RENDER_ALLOW),
 };
 
-static const struct drm_driver vc4_drm_driver = {
+const struct drm_driver vc4_drm_driver = {
 	.driver_features = (DRIVER_MODESET |
 			    DRIVER_ATOMIC |
 			    DRIVER_GEM |
@@ -225,7 +225,7 @@ static const struct drm_driver vc4_drm_driver = {
 	.patchlevel = DRIVER_PATCHLEVEL,
 };
 
-static const struct drm_driver vc5_drm_driver = {
+const struct drm_driver vc5_drm_driver = {
 	.driver_features = (DRIVER_MODESET |
 			    DRIVER_ATOMIC |
 			    DRIVER_GEM),
diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
index e0be7a81a24a..418f4f308e36 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.h
+++ b/drivers/gpu/drm/vc4/vc4_drv.h
@@ -24,6 +24,9 @@
 struct drm_device;
 struct drm_gem_object;
 
+extern const struct drm_driver vc4_drm_driver;
+extern const struct drm_driver vc5_drm_driver;
+
 /* Don't forget to update vc4_bo.c: bo_type_names[] when adding to
  * this.
  */
@@ -523,6 +526,8 @@ struct vc4_crtc_data {
 	int hvs_output;
 };
 
+extern const struct vc4_crtc_data vc4_txp_crtc_data;
+
 struct vc4_pv_data {
 	struct vc4_crtc_data	base;
 
@@ -535,6 +540,15 @@ struct vc4_pv_data {
 	enum vc4_encoder_type encoder_types[4];
 };
 
+extern const struct vc4_pv_data bcm2835_pv0_data;
+extern const struct vc4_pv_data bcm2835_pv1_data;
+extern const struct vc4_pv_data bcm2835_pv2_data;
+extern const struct vc4_pv_data bcm2711_pv0_data;
+extern const struct vc4_pv_data bcm2711_pv1_data;
+extern const struct vc4_pv_data bcm2711_pv2_data;
+extern const struct vc4_pv_data bcm2711_pv3_data;
+extern const struct vc4_pv_data bcm2711_pv4_data;
+
 struct vc4_crtc {
 	struct drm_crtc base;
 	struct platform_device *pdev;
@@ -920,6 +934,8 @@ int vc4_page_flip(struct drm_crtc *crtc,
 		  struct drm_pending_vblank_event *event,
 		  uint32_t flags,
 		  struct drm_modeset_acquire_ctx *ctx);
+int vc4_crtc_atomic_check(struct drm_crtc *crtc,
+			  struct drm_atomic_state *state);
 struct drm_crtc_state *vc4_crtc_duplicate_state(struct drm_crtc *crtc);
 void vc4_crtc_destroy_state(struct drm_crtc *crtc,
 			    struct drm_crtc_state *state);
diff --git a/drivers/gpu/drm/vc4/vc4_txp.c b/drivers/gpu/drm/vc4/vc4_txp.c
index 4f7ce5d3e8ad..2b69454b8534 100644
--- a/drivers/gpu/drm/vc4/vc4_txp.c
+++ b/drivers/gpu/drm/vc4/vc4_txp.c
@@ -479,7 +479,7 @@ static irqreturn_t vc4_txp_interrupt(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
-static const struct vc4_crtc_data vc4_txp_crtc_data = {
+const struct vc4_crtc_data vc4_txp_crtc_data = {
 	.name = "txp",
 	.debugfs_name = "txp_regs",
 	.hvs_available_channels = BIT(2),