1/*
  2 * Copyright (C) 2016 Noralf Trønnes
  3 *
  4 * This program is free software; you can redistribute it and/or modify
  5 * it under the terms of the GNU General Public License as published by
  6 * the Free Software Foundation; either version 2 of the License, or
  7 * (at your option) any later version.
  8 */
  9
 10#include <drm/drmP.h>
 11#include <drm/drm_atomic.h>
 12#include <drm/drm_atomic_helper.h>
 13#include <drm/drm_crtc_helper.h>
 14#include <drm/drm_plane_helper.h>
 15#include <drm/drm_simple_kms_helper.h>
 16#include <linux/slab.h>
 17
 18/**
 19 * DOC: overview
 20 *
 21 * This helper library provides helpers for drivers for simple display
 22 * hardware.
 23 *
 24 * drm_simple_display_pipe_init() initializes a simple display pipeline
 25 * which has only one full-screen scanout buffer feeding one output. The
 26 * pipeline is represented by &struct drm_simple_display_pipe and binds
 27 * together &drm_plane, &drm_crtc and &drm_encoder structures into one fixed
 28 * entity. Some flexibility for code reuse is provided through a separately
 29 * allocated &drm_connector object and supporting optional &drm_bridge
 30 * encoder drivers.
 31 */
 32
 33static const struct drm_encoder_funcs drm_simple_kms_encoder_funcs = {
 34	.destroy = drm_encoder_cleanup,
 35};
 36
 37static enum drm_mode_status
 38drm_simple_kms_crtc_mode_valid(struct drm_crtc *crtc,
 39			       const struct drm_display_mode *mode)
 40{
 41	struct drm_simple_display_pipe *pipe;
 42
 43	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 44	if (!pipe->funcs || !pipe->funcs->mode_valid)
 45		/* Anything goes */
 46		return MODE_OK;
 47
 48	return pipe->funcs->mode_valid(crtc, mode);
 49}
 50
 51static int drm_simple_kms_crtc_check(struct drm_crtc *crtc,
 52				     struct drm_crtc_state *state)
 53{
 54	bool has_primary = state->plane_mask &
 55			   BIT(drm_plane_index(crtc->primary));
 56
 57	/* We always want to have an active plane with an active CRTC */
 58	if (has_primary != state->enable)
 59		return -EINVAL;
 60
 61	return drm_atomic_add_affected_planes(state->state, crtc);
 62}
 63
 64static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc,
 65				       struct drm_crtc_state *old_state)
 66{
 67	struct drm_simple_display_pipe *pipe;
 68
 69	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 70	if (!pipe->funcs || !pipe->funcs->enable)
 71		return;
 72
 73	pipe->funcs->enable(pipe, crtc->state);
 74}
 75
 76static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc,
 77					struct drm_crtc_state *old_state)
 78{
 79	struct drm_simple_display_pipe *pipe;
 80
 81	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 82	if (!pipe->funcs || !pipe->funcs->disable)
 83		return;
 84
 85	pipe->funcs->disable(pipe);
 86}
 87
 88static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
 89	.mode_valid = drm_simple_kms_crtc_mode_valid,
 90	.atomic_check = drm_simple_kms_crtc_check,
 91	.atomic_enable = drm_simple_kms_crtc_enable,
 92	.atomic_disable = drm_simple_kms_crtc_disable,
 93};
 94
 95static int drm_simple_kms_crtc_enable_vblank(struct drm_crtc *crtc)
 96{
 97	struct drm_simple_display_pipe *pipe;
 98
 99	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
100	if (!pipe->funcs || !pipe->funcs->enable_vblank)
101		return 0;
102
103	return pipe->funcs->enable_vblank(pipe);
104}
105
106static void drm_simple_kms_crtc_disable_vblank(struct drm_crtc *crtc)
107{
108	struct drm_simple_display_pipe *pipe;
109
110	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
111	if (!pipe->funcs || !pipe->funcs->disable_vblank)
112		return;
113
114	pipe->funcs->disable_vblank(pipe);
115}
116
117static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = {
118	.reset = drm_atomic_helper_crtc_reset,
119	.destroy = drm_crtc_cleanup,
120	.set_config = drm_atomic_helper_set_config,
121	.page_flip = drm_atomic_helper_page_flip,
122	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
123	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
124	.enable_vblank = drm_simple_kms_crtc_enable_vblank,
125	.disable_vblank = drm_simple_kms_crtc_disable_vblank,
126};
127
128static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
129					struct drm_plane_state *plane_state)
130{
131	struct drm_simple_display_pipe *pipe;
132	struct drm_crtc_state *crtc_state;
133	int ret;
134
135	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
136	crtc_state = drm_atomic_get_new_crtc_state(plane_state->state,
137						   &pipe->crtc);
138
139	ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
140						  DRM_PLANE_HELPER_NO_SCALING,
141						  DRM_PLANE_HELPER_NO_SCALING,
142						  false, true);
143	if (ret)
144		return ret;
145
146	if (!plane_state->visible)
147		return 0;
148
149	if (!pipe->funcs || !pipe->funcs->check)
150		return 0;
151
152	return pipe->funcs->check(pipe, plane_state, crtc_state);
153}
154
155static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,
156					struct drm_plane_state *old_pstate)
157{
158	struct drm_simple_display_pipe *pipe;
159
160	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
161	if (!pipe->funcs || !pipe->funcs->update)
162		return;
163
164	pipe->funcs->update(pipe, old_pstate);
165}
166
167static int drm_simple_kms_plane_prepare_fb(struct drm_plane *plane,
168					   struct drm_plane_state *state)
169{
170	struct drm_simple_display_pipe *pipe;
171
172	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
173	if (!pipe->funcs || !pipe->funcs->prepare_fb)
174		return 0;
175
176	return pipe->funcs->prepare_fb(pipe, state);
177}
178
179static void drm_simple_kms_plane_cleanup_fb(struct drm_plane *plane,
180					    struct drm_plane_state *state)
181{
182	struct drm_simple_display_pipe *pipe;
183
184	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
185	if (!pipe->funcs || !pipe->funcs->cleanup_fb)
186		return;
187
188	pipe->funcs->cleanup_fb(pipe, state);
189}
190
191static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {
192	.prepare_fb = drm_simple_kms_plane_prepare_fb,
193	.cleanup_fb = drm_simple_kms_plane_cleanup_fb,
194	.atomic_check = drm_simple_kms_plane_atomic_check,
195	.atomic_update = drm_simple_kms_plane_atomic_update,
196};
197
198static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
199	.update_plane		= drm_atomic_helper_update_plane,
200	.disable_plane		= drm_atomic_helper_disable_plane,
201	.destroy		= drm_plane_cleanup,
202	.reset			= drm_atomic_helper_plane_reset,
203	.atomic_duplicate_state	= drm_atomic_helper_plane_duplicate_state,
204	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
205};
206
207/**
208 * drm_simple_display_pipe_attach_bridge - Attach a bridge to the display pipe
209 * @pipe: simple display pipe object
210 * @bridge: bridge to attach
211 *
212 * Makes it possible to still use the drm_simple_display_pipe helpers when
213 * a DRM bridge has to be used.
214 *
215 * Note that you probably want to initialize the pipe by passing a NULL
216 * connector to drm_simple_display_pipe_init().
217 *
218 * Returns:
219 * Zero on success, negative error code on failure.
220 */
221int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
222					  struct drm_bridge *bridge)
223{
224	return drm_bridge_attach(&pipe->encoder, bridge, NULL);
225}
226EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge);
227
228/**
229 * drm_simple_display_pipe_init - Initialize a simple display pipeline
230 * @dev: DRM device
231 * @pipe: simple display pipe object to initialize
232 * @funcs: callbacks for the display pipe (optional)
233 * @formats: array of supported formats (DRM_FORMAT\_\*)
234 * @format_count: number of elements in @formats
235 * @format_modifiers: array of formats modifiers
236 * @connector: connector to attach and register (optional)
237 *
238 * Sets up a display pipeline which consist of a really simple
239 * plane-crtc-encoder pipe.
240 *
241 * If a connector is supplied, the pipe will be coupled with the provided
242 * connector. You may supply a NULL connector when using drm bridges, that
243 * handle connectors themselves (see drm_simple_display_pipe_attach_bridge()).
244 *
245 * Teardown of a simple display pipe is all handled automatically by the drm
246 * core through calling drm_mode_config_cleanup(). Drivers afterwards need to
247 * release the memory for the structure themselves.
248 *
249 * Returns:
250 * Zero on success, negative error code on failure.
251 */
252int drm_simple_display_pipe_init(struct drm_device *dev,
253			struct drm_simple_display_pipe *pipe,
254			const struct drm_simple_display_pipe_funcs *funcs,
255			const uint32_t *formats, unsigned int format_count,
256			const uint64_t *format_modifiers,
257			struct drm_connector *connector)
258{
259	struct drm_encoder *encoder = &pipe->encoder;
260	struct drm_plane *plane = &pipe->plane;
261	struct drm_crtc *crtc = &pipe->crtc;
262	int ret;
263
264	pipe->connector = connector;
265	pipe->funcs = funcs;
266
267	drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs);
268	ret = drm_universal_plane_init(dev, plane, 0,
269				       &drm_simple_kms_plane_funcs,
270				       formats, format_count,
271				       format_modifiers,
272				       DRM_PLANE_TYPE_PRIMARY, NULL);
273	if (ret)
274		return ret;
275
276	drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs);
277	ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
278					&drm_simple_kms_crtc_funcs, NULL);
279	if (ret)
280		return ret;
281
282	encoder->possible_crtcs = 1 << drm_crtc_index(crtc);
283	ret = drm_encoder_init(dev, encoder, &drm_simple_kms_encoder_funcs,
284			       DRM_MODE_ENCODER_NONE, NULL);
285	if (ret || !connector)
286		return ret;
287
288	return drm_mode_connector_attach_encoder(connector, encoder);
289}
290EXPORT_SYMBOL(drm_simple_display_pipe_init);
291
292MODULE_LICENSE("GPL");