1/*
2 * Copyright (C) 2014 Intel Corporation
3 *
4 * DRM universal plane helper functions
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice (including the next
14 * paragraph) shall be included in all copies or substantial portions of the
15 * Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * SOFTWARE.
24 */
25
26#include <linux/list.h>
27
28#include <drm/drm_atomic.h>
29#include <drm/drm_atomic_helper.h>
30#include <drm/drm_atomic_uapi.h>
31#include <drm/drm_crtc_helper.h>
32#include <drm/drm_device.h>
33#include <drm/drm_encoder.h>
34#include <drm/drm_plane_helper.h>
35#include <drm/drm_rect.h>
36
37#define SUBPIXEL_MASK 0xffff
38
39/**
40 * DOC: overview
41 *
42 * This helper library has two parts. The first part has support to implement
43 * primary plane support on top of the normal CRTC configuration interface.
44 * Since the legacy &drm_mode_config_funcs.set_config interface ties the primary
45 * plane together with the CRTC state this does not allow userspace to disable
46 * the primary plane itself. The default primary plane only expose XRBG8888 and
47 * ARGB8888 as valid pixel formats for the attached framebuffer.
48 *
49 * Drivers are highly recommended to implement proper support for primary
50 * planes, and newly merged drivers must not rely upon these transitional
51 * helpers.
52 *
53 * The second part also implements transitional helpers which allow drivers to
54 * gradually switch to the atomic helper infrastructure for plane updates. Once
55 * that switch is complete drivers shouldn't use these any longer, instead using
56 * the proper legacy implementations for update and disable plane hooks provided
57 * by the atomic helpers.
58 *
59 * Again drivers are strongly urged to switch to the new interfaces.
60 *
61 * The plane helpers share the function table structures with other helpers,
62 * specifically also the atomic helpers. See &struct drm_plane_helper_funcs for
63 * the details.
64 */
65
66/*
67 * Returns the connectors currently associated with a CRTC.  This function
68 * should be called twice:  once with a NULL connector list to retrieve
69 * the list size, and once with the properly allocated list to be filled in.
70 */
71static int get_connectors_for_crtc(struct drm_crtc *crtc,
72				   struct drm_connector **connector_list,
73				   int num_connectors)
74{
75	struct drm_device *dev = crtc->dev;
76	struct drm_connector *connector;
77	struct drm_connector_list_iter conn_iter;
78	int count = 0;
79
80	/*
81	 * Note: Once we change the plane hooks to more fine-grained locking we
82	 * need to grab the connection_mutex here to be able to make these
83	 * checks.
84	 */
85	WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
86
87	drm_connector_list_iter_begin(dev, &conn_iter);
88	drm_for_each_connector_iter(connector, &conn_iter) {
89		if (connector->encoder && connector->encoder->crtc == crtc) {
90			if (connector_list != NULL && count < num_connectors)
91				*(connector_list++) = connector;
92
93			count++;
94		}
95	}
96	drm_connector_list_iter_end(&conn_iter);
97
98	return count;
99}
100
101static int drm_plane_helper_check_update(struct drm_plane *plane,
102					 struct drm_crtc *crtc,
103					 struct drm_framebuffer *fb,
104					 struct drm_rect *src,
105					 struct drm_rect *dst,
106					 unsigned int rotation,
107					 int min_scale,
108					 int max_scale,
109					 bool can_position,
110					 bool can_update_disabled,
111					 bool *visible)
112{
113	struct drm_plane_state plane_state = {
114		.plane = plane,
115		.crtc = crtc,
116		.fb = fb,
117		.src_x = src->x1,
118		.src_y = src->y1,
119		.src_w = drm_rect_width(src),
120		.src_h = drm_rect_height(src),
121		.crtc_x = dst->x1,
122		.crtc_y = dst->y1,
123		.crtc_w = drm_rect_width(dst),
124		.crtc_h = drm_rect_height(dst),
125		.rotation = rotation,
126	};
127	struct drm_crtc_state crtc_state = {
128		.crtc = crtc,
129		.enable = crtc->enabled,
130		.mode = crtc->mode,
131	};
132	int ret;
133
134	ret = drm_atomic_helper_check_plane_state(&plane_state, &crtc_state,
135						  min_scale, max_scale,
136						  can_position,
137						  can_update_disabled);
138	if (ret)
139		return ret;
140
141	*src = plane_state.src;
142	*dst = plane_state.dst;
143	*visible = plane_state.visible;
144
145	return 0;
146}
147
148static int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
149				     struct drm_framebuffer *fb,
150				     int crtc_x, int crtc_y,
151				     unsigned int crtc_w, unsigned int crtc_h,
152				     uint32_t src_x, uint32_t src_y,
153				     uint32_t src_w, uint32_t src_h,
154				     struct drm_modeset_acquire_ctx *ctx)
155{
156	struct drm_mode_set set = {
157		.crtc = crtc,
158		.fb = fb,
159		.mode = &crtc->mode,
160		.x = src_x >> 16,
161		.y = src_y >> 16,
162	};
163	struct drm_rect src = {
164		.x1 = src_x,
165		.y1 = src_y,
166		.x2 = src_x + src_w,
167		.y2 = src_y + src_h,
168	};
169	struct drm_rect dest = {
170		.x1 = crtc_x,
171		.y1 = crtc_y,
172		.x2 = crtc_x + crtc_w,
173		.y2 = crtc_y + crtc_h,
174	};
175	struct drm_connector **connector_list;
176	int num_connectors, ret;
177	bool visible;
178
179	ret = drm_plane_helper_check_update(plane, crtc, fb,
180					    &src, &dest,
181					    DRM_MODE_ROTATE_0,
182					    DRM_PLANE_HELPER_NO_SCALING,
183					    DRM_PLANE_HELPER_NO_SCALING,
184					    false, false, &visible);
185	if (ret)
186		return ret;
187
188	if (!visible)
189		/*
190		 * Primary plane isn't visible.  Note that unless a driver
191		 * provides their own disable function, this will just
192		 * wind up returning -EINVAL to userspace.
193		 */
194		return plane->funcs->disable_plane(plane, ctx);
195
196	/* Find current connectors for CRTC */
197	num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
198	BUG_ON(num_connectors == 0);
199	connector_list = kcalloc(num_connectors, sizeof(*connector_list),
200				 GFP_KERNEL);
201	if (!connector_list)
202		return -ENOMEM;
203	get_connectors_for_crtc(crtc, connector_list, num_connectors);
204
205	set.connectors = connector_list;
206	set.num_connectors = num_connectors;
207
208	/*
209	 * We call set_config() directly here rather than using
210	 * drm_mode_set_config_internal.  We're reprogramming the same
211	 * connectors that were already in use, so we shouldn't need the extra
212	 * cross-CRTC fb refcounting to accomodate stealing connectors.
213	 * drm_mode_setplane() already handles the basic refcounting for the
214	 * framebuffers involved in this operation.
215	 */
216	ret = crtc->funcs->set_config(&set, ctx);
217
218	kfree(connector_list);
219	return ret;
220}
221
222static int drm_primary_helper_disable(struct drm_plane *plane,
223				      struct drm_modeset_acquire_ctx *ctx)
224{
225	return -EINVAL;
226}
227
228/**
229 * drm_primary_helper_destroy() - Helper for primary plane destruction
230 * @plane: plane to destroy
231 *
232 * Provides a default plane destroy handler for primary planes.  This handler
233 * is called during CRTC destruction.  We disable the primary plane, remove
234 * it from the DRM plane list, and deallocate the plane structure.
235 */
236void drm_primary_helper_destroy(struct drm_plane *plane)
237{
238	drm_plane_cleanup(plane);
239	kfree(plane);
240}
241EXPORT_SYMBOL(drm_primary_helper_destroy);
242
243const struct drm_plane_funcs drm_primary_helper_funcs = {
244	.update_plane = drm_primary_helper_update,
245	.disable_plane = drm_primary_helper_disable,
246	.destroy = drm_primary_helper_destroy,
247};
248EXPORT_SYMBOL(drm_primary_helper_funcs);
249