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Commit 5b809074 authored by Noralf Trønnes's avatar Noralf Trønnes Committed by Daniel Vetter
Browse files

drm: Add helper for simple display pipeline 



Provides helper functions for drivers that have a simple display
pipeline. Plane, crtc and encoder are collapsed into one entity.

Changes since v4:
- Remove drm_connector_register() call
- Forgot to assign pipe->connector

Changes since v3:
- (struct drm_simple_display_pipe *)->funcs should be const

Changes since v2:
- Drop Kconfig knob DRM_KMS_HELPER
- Expand documentation

Changes since v1:
- Add DOC header and add to gpu.tmpl
- Fix docs: @funcs is optional, "negative error code",
  "This hook is optional."
- Add checks to drm_simple_kms_plane_atomic_check()

Cc: jsarha@ti.com
Signed-off-by: default avatarNoralf Trønnes <noralf@tronnes.org>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1465570559-14238-1-git-send-email-noralf@tronnes.org
parent c2a441fe

Documentation/DocBook/gpu.tmpl

+6 −0
Original line number Diff line number Diff line
@@ -1688,6 +1688,12 @@ void intel_crt_init(struct drm_device *dev) 
!Edrivers/gpu/drm/drm_panel.c

!Pdrivers/gpu/drm/drm_panel.c drm panel

    </sect2>

    <sect2>

      <title>Simple KMS Helper Reference</title>

!Iinclude/drm/drm_simple_kms_helper.h

!Edrivers/gpu/drm/drm_simple_kms_helper.c

!Pdrivers/gpu/drm/drm_simple_kms_helper.c overview

    </sect2>

  </sect1>



  <!-- Internals: kms properties -->

drivers/gpu/drm/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -23,7 +23,8 @@ drm-$(CONFIG_AGP) += drm_agpsupport.o 


drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o \

		drm_plane_helper.o drm_dp_mst_topology.o drm_atomic_helper.o \

		drm_kms_helper_common.o drm_dp_dual_mode_helper.o

		drm_kms_helper_common.o drm_dp_dual_mode_helper.o \

		drm_simple_kms_helper.o



drm_kms_helper-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o

drm_kms_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fb_helper.o

drivers/gpu/drm/drm_simple_kms_helper.c

0 → 100644
+205 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2016 Noralf Trønnes

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 */



#include <drm/drmP.h>

#include <drm/drm_atomic.h>

#include <drm/drm_atomic_helper.h>

#include <drm/drm_crtc_helper.h>

#include <drm/drm_plane_helper.h>

#include <drm/drm_simple_kms_helper.h>

#include <linux/slab.h>



/**

 * DOC: overview

 *

 * This helper library provides helpers for drivers for simple display

 * hardware.

 *

 * drm_simple_display_pipe_init() initializes a simple display pipeline

 * which has only one full-screen scanout buffer feeding one output. The

 * pipeline is represented by struct &drm_simple_display_pipe and binds

 * together &drm_plane, &drm_crtc and &drm_encoder structures into one fixed

 * entity. Some flexibility for code reuse is provided through a separately

 * allocated &drm_connector object and supporting optional &drm_bridge

 * encoder drivers.

 */



static const struct drm_encoder_funcs drm_simple_kms_encoder_funcs = {

	.destroy = drm_encoder_cleanup,

};



static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc)

{

	struct drm_simple_display_pipe *pipe;



	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);

	if (!pipe->funcs || !pipe->funcs->enable)

		return;



	pipe->funcs->enable(pipe, crtc->state);

}



static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc)

{

	struct drm_simple_display_pipe *pipe;



	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);

	if (!pipe->funcs || !pipe->funcs->disable)

		return;



	pipe->funcs->disable(pipe);

}



static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {

	.disable = drm_simple_kms_crtc_disable,

	.enable = drm_simple_kms_crtc_enable,

};



static const struct drm_crtc_funcs drm_simple_kms_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,

};



static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,

					struct drm_plane_state *plane_state)

{

	struct drm_rect src = {

		.x1 = plane_state->src_x,

		.y1 = plane_state->src_y,

		.x2 = plane_state->src_x + plane_state->src_w,

		.y2 = plane_state->src_y + plane_state->src_h,

	};

	struct drm_rect dest = {

		.x1 = plane_state->crtc_x,

		.y1 = plane_state->crtc_y,

		.x2 = plane_state->crtc_x + plane_state->crtc_w,

		.y2 = plane_state->crtc_y + plane_state->crtc_h,

	};

	struct drm_rect clip = { 0 };

	struct drm_simple_display_pipe *pipe;

	struct drm_crtc_state *crtc_state;

	bool visible;

	int ret;



	pipe = container_of(plane, struct drm_simple_display_pipe, plane);

	crtc_state = drm_atomic_get_existing_crtc_state(plane_state->state,

							&pipe->crtc);

	if (crtc_state->enable != !!plane_state->crtc)

		return -EINVAL; /* plane must match crtc enable state */



	if (!crtc_state->enable)

		return 0; /* nothing to check when disabling or disabled */



	clip.x2 = crtc_state->adjusted_mode.hdisplay;

	clip.y2 = crtc_state->adjusted_mode.vdisplay;

	ret = drm_plane_helper_check_update(plane, &pipe->crtc,

					    plane_state->fb,

					    &src, &dest, &clip,

					    DRM_PLANE_HELPER_NO_SCALING,

					    DRM_PLANE_HELPER_NO_SCALING,

					    false, true, &visible);

	if (ret)

		return ret;



	if (!visible)

		return -EINVAL;



	if (!pipe->funcs || !pipe->funcs->check)

		return 0;



	return pipe->funcs->check(pipe, plane_state, crtc_state);

}



static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,

					struct drm_plane_state *pstate)

{

	struct drm_simple_display_pipe *pipe;



	pipe = container_of(plane, struct drm_simple_display_pipe, plane);

	if (!pipe->funcs || !pipe->funcs->update)

		return;



	pipe->funcs->update(pipe, pstate);

}



static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {

	.atomic_check = drm_simple_kms_plane_atomic_check,

	.atomic_update = drm_simple_kms_plane_atomic_update,

};



static const struct drm_plane_funcs drm_simple_kms_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,

};



/**

 * drm_simple_display_pipe_init - Initialize a simple display pipeline

 * @dev: DRM device

 * @pipe: simple display pipe object to initialize

 * @funcs: callbacks for the display pipe (optional)

 * @formats: array of supported formats (%DRM_FORMAT_*)

 * @format_count: number of elements in @formats

 * @connector: connector to attach and register

 *

 * Sets up a display pipeline which consist of a really simple

 * plane-crtc-encoder pipe coupled with the provided connector.

 * Teardown of a simple display pipe is all handled automatically by the drm

 * core through calling drm_mode_config_cleanup(). Drivers afterwards need to

 * release the memory for the structure themselves.

 *

 * Returns:

 * Zero on success, negative error code on failure.

 */

int drm_simple_display_pipe_init(struct drm_device *dev,

			struct drm_simple_display_pipe *pipe,

			const struct drm_simple_display_pipe_funcs *funcs,

			const uint32_t *formats, unsigned int format_count,

			struct drm_connector *connector)

{

	struct drm_encoder *encoder = &pipe->encoder;

	struct drm_plane *plane = &pipe->plane;

	struct drm_crtc *crtc = &pipe->crtc;

	int ret;



	pipe->connector = connector;

	pipe->funcs = funcs;



	drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs);

	ret = drm_universal_plane_init(dev, plane, 0,

				       &drm_simple_kms_plane_funcs,

				       formats, format_count,

				       DRM_PLANE_TYPE_PRIMARY, NULL);

	if (ret)

		return ret;



	drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs);

	ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,

					&drm_simple_kms_crtc_funcs, NULL);

	if (ret)

		return ret;



	encoder->possible_crtcs = 1 << drm_crtc_index(crtc);

	ret = drm_encoder_init(dev, encoder, &drm_simple_kms_encoder_funcs,

			       DRM_MODE_ENCODER_NONE, NULL);

	if (ret)

		return ret;



	return drm_mode_connector_attach_encoder(connector, encoder);

}

EXPORT_SYMBOL(drm_simple_display_pipe_init);



MODULE_LICENSE("GPL");

include/drm/drm_simple_kms_helper.h

0 → 100644
+94 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2016 Noralf Trønnes

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 */



#ifndef __LINUX_DRM_SIMPLE_KMS_HELPER_H

#define __LINUX_DRM_SIMPLE_KMS_HELPER_H



struct drm_simple_display_pipe;



/**

 * struct drm_simple_display_pipe_funcs - helper operations for a simple

 *                                        display pipeline

 */

struct drm_simple_display_pipe_funcs {

	/**

	 * @enable:

	 *

	 * This function should be used to enable the pipeline.

	 * It is called when the underlying crtc is enabled.

	 * This hook is optional.

	 */

	void (*enable)(struct drm_simple_display_pipe *pipe,

		       struct drm_crtc_state *crtc_state);

	/**

	 * @disable:

	 *

	 * This function should be used to disable the pipeline.

	 * It is called when the underlying crtc is disabled.

	 * This hook is optional.

	 */

	void (*disable)(struct drm_simple_display_pipe *pipe);



	/**

	 * @check:

	 *

	 * This function is called in the check phase of an atomic update,

	 * specifically when the underlying plane is checked.

	 * The simple display pipeline helpers already check that the plane is

	 * not scaled, fills the entire visible area and is always enabled

	 * when the crtc is also enabled.

	 * This hook is optional.

	 *

	 * RETURNS:

	 *

	 * 0 on success, -EINVAL if the state or the transition can't be

	 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an

	 * attempt to obtain another state object ran into a &drm_modeset_lock

	 * deadlock.

	 */

	int (*check)(struct drm_simple_display_pipe *pipe,

		     struct drm_plane_state *plane_state,

		     struct drm_crtc_state *crtc_state);

	/**

	 * @update:

	 *

	 * This function is called when the underlying plane state is updated.

	 * This hook is optional.

	 */

	void (*update)(struct drm_simple_display_pipe *pipe,

		       struct drm_plane_state *plane_state);

};



/**

 * struct drm_simple_display_pipe - simple display pipeline

 * @crtc: CRTC control structure

 * @plane: Plane control structure

 * @encoder: Encoder control structure

 * @connector: Connector control structure

 * @funcs: Pipeline control functions (optional)

 *

 * Simple display pipeline with plane, crtc and encoder collapsed into one

 * entity. It should be initialized by calling drm_simple_display_pipe_init().

 */

struct drm_simple_display_pipe {

	struct drm_crtc crtc;

	struct drm_plane plane;

	struct drm_encoder encoder;

	struct drm_connector *connector;



	const struct drm_simple_display_pipe_funcs *funcs;

};



int drm_simple_display_pipe_init(struct drm_device *dev,

			struct drm_simple_display_pipe *pipe,

			const struct drm_simple_display_pipe_funcs *funcs,

			const uint32_t *formats, unsigned int format_count,

			struct drm_connector *connector);



#endif /* __LINUX_DRM_SIMPLE_KMS_HELPER_H */