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		.visible = *visible,
127	};
128	struct drm_crtc_state crtc_state = {
129		.crtc = crtc,
130		.enable = crtc->enabled,
131		.mode = crtc->mode,
132	};
133	int ret;
134
135	ret = drm_atomic_helper_check_plane_state(&plane_state, &crtc_state,
136						  min_scale, max_scale,
137						  can_position,
138						  can_update_disabled);
139	if (ret)
140		return ret;
141
142	*src = plane_state.src;
143	*dst = plane_state.dst;
144	*visible = plane_state.visible;
145
146	return 0;
147}
148
149static int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
150				     struct drm_framebuffer *fb,
151				     int crtc_x, int crtc_y,
152				     unsigned int crtc_w, unsigned int crtc_h,
153				     uint32_t src_x, uint32_t src_y,
154				     uint32_t src_w, uint32_t src_h,
155				     struct drm_modeset_acquire_ctx *ctx)
156{
157	struct drm_mode_set set = {
158		.crtc = crtc,
159		.fb = fb,
160		.mode = &crtc->mode,
161		.x = src_x >> 16,
162		.y = src_y >> 16,
163	};
164	struct drm_rect src = {
165		.x1 = src_x,
166		.y1 = src_y,
167		.x2 = src_x + src_w,
168		.y2 = src_y + src_h,
169	};
170	struct drm_rect dest = {
171		.x1 = crtc_x,
172		.y1 = crtc_y,
173		.x2 = crtc_x + crtc_w,
174		.y2 = crtc_y + crtc_h,
175	};
176	struct drm_connector **connector_list;
177	int num_connectors, ret;
178	bool visible;
179
180	ret = drm_plane_helper_check_update(plane, crtc, fb,
181					    &src, &dest,
182					    DRM_MODE_ROTATE_0,
183					    DRM_PLANE_HELPER_NO_SCALING,
184					    DRM_PLANE_HELPER_NO_SCALING,
185					    false, false, &visible);
186	if (ret)
187		return ret;
188
189	if (!visible)
190		/*
191		 * Primary plane isn't visible.  Note that unless a driver
192		 * provides their own disable function, this will just
193		 * wind up returning -EINVAL to userspace.
194		 */
195		return plane->funcs->disable_plane(plane, ctx);
196
197	/* Find current connectors for CRTC */
198	num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
199	BUG_ON(num_connectors == 0);
200	connector_list = kcalloc(num_connectors, sizeof(*connector_list),
201				 GFP_KERNEL);
202	if (!connector_list)
203		return -ENOMEM;
204	get_connectors_for_crtc(crtc, connector_list, num_connectors);
205
206	set.connectors = connector_list;
207	set.num_connectors = num_connectors;
208
209	/*
210	 * We call set_config() directly here rather than using
211	 * drm_mode_set_config_internal.  We're reprogramming the same
212	 * connectors that were already in use, so we shouldn't need the extra
213	 * cross-CRTC fb refcounting to accomodate stealing connectors.
214	 * drm_mode_setplane() already handles the basic refcounting for the
215	 * framebuffers involved in this operation.
216	 */
217	ret = crtc->funcs->set_config(&set, ctx);
218
219	kfree(connector_list);
220	return ret;
221}
222
223static int drm_primary_helper_disable(struct drm_plane *plane,
224				      struct drm_modeset_acquire_ctx *ctx)
225{
226	return -EINVAL;
227}
228
229/**
230 * drm_primary_helper_destroy() - Helper for primary plane destruction
231 * @plane: plane to destroy
232 *
233 * Provides a default plane destroy handler for primary planes.  This handler
234 * is called during CRTC destruction.  We disable the primary plane, remove
235 * it from the DRM plane list, and deallocate the plane structure.
236 */
237void drm_primary_helper_destroy(struct drm_plane *plane)
238{
239	drm_plane_cleanup(plane);
240	kfree(plane);
241}
242EXPORT_SYMBOL(drm_primary_helper_destroy);
243
244const struct drm_plane_funcs drm_primary_helper_funcs = {
245	.update_plane = drm_primary_helper_update,
246	.disable_plane = drm_primary_helper_disable,
247	.destroy = drm_primary_helper_destroy,
248};
249EXPORT_SYMBOL(drm_primary_helper_funcs);