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_drv.h>
 34#include <drm/drm_encoder.h>
 35#include <drm/drm_plane_helper.h>
 36#include <drm/drm_print.h>
 37#include <drm/drm_rect.h>
 38
 39#define SUBPIXEL_MASK 0xffff
 40
 41/**
 42 * DOC: overview
 43 *
 44 * This helper library has two parts. The first part has support to implement
 45 * primary plane support on top of the normal CRTC configuration interface.
 46 * Since the legacy &drm_mode_config_funcs.set_config interface ties the primary
 47 * plane together with the CRTC state this does not allow userspace to disable
 48 * the primary plane itself. The default primary plane only expose XRBG8888 and
 49 * ARGB8888 as valid pixel formats for the attached framebuffer.
 50 *
 51 * Drivers are highly recommended to implement proper support for primary
 52 * planes, and newly merged drivers must not rely upon these transitional
 53 * helpers.
 54 *
 55 * The second part also implements transitional helpers which allow drivers to
 56 * gradually switch to the atomic helper infrastructure for plane updates. Once
 57 * that switch is complete drivers shouldn't use these any longer, instead using
 58 * the proper legacy implementations for update and disable plane hooks provided
 59 * by the atomic helpers.
 60 *
 61 * Again drivers are strongly urged to switch to the new interfaces.
 62 *
 63 * The plane helpers share the function table structures with other helpers,
 64 * specifically also the atomic helpers. See &struct drm_plane_helper_funcs for
 65 * the details.
 66 */
 67
 68/*
 69 * Returns the connectors currently associated with a CRTC.  This function
 70 * should be called twice:  once with a NULL connector list to retrieve
 71 * the list size, and once with the properly allocated list to be filled in.
 72 */
 73static int get_connectors_for_crtc(struct drm_crtc *crtc,
 74				   struct drm_connector **connector_list,
 75				   int num_connectors)
 76{
 77	struct drm_device *dev = crtc->dev;
 78	struct drm_connector *connector;
 79	struct drm_connector_list_iter conn_iter;
 80	int count = 0;
 81
 82	/*
 83	 * Note: Once we change the plane hooks to more fine-grained locking we
 84	 * need to grab the connection_mutex here to be able to make these
 85	 * checks.
 86	 */
 87	WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
 88
 89	drm_connector_list_iter_begin(dev, &conn_iter);
 90	drm_for_each_connector_iter(connector, &conn_iter) {
 91		if (connector->encoder && connector->encoder->crtc == crtc) {
 92			if (connector_list != NULL && count < num_connectors)
 93				*(connector_list++) = connector;
 94
 95			count++;
 96		}
 97	}
 98	drm_connector_list_iter_end(&conn_iter);
 99
100	return count;
101}
102
103static int drm_plane_helper_check_update(struct drm_plane *plane,
104					 struct drm_crtc *crtc,
105					 struct drm_framebuffer *fb,
106					 struct drm_rect *src,
107					 struct drm_rect *dst,
108					 unsigned int rotation,
109					 int min_scale,
110					 int max_scale,
111					 bool can_position,
112					 bool can_update_disabled,
113					 bool *visible)
114{
115	struct drm_plane_state plane_state = {
116		.plane = plane,
117		.crtc = crtc,
118		.fb = fb,
119		.src_x = src->x1,
120		.src_y = src->y1,
121		.src_w = drm_rect_width(src),
122		.src_h = drm_rect_height(src),
123		.crtc_x = dst->x1,
124		.crtc_y = dst->y1,
125		.crtc_w = drm_rect_width(dst),
126		.crtc_h = drm_rect_height(dst),
127		.rotation = rotation,
128	};
129	struct drm_crtc_state crtc_state = {
130		.crtc = crtc,
131		.enable = crtc->enabled,
132		.mode = crtc->mode,
133	};
134	int ret;
135
136	ret = drm_atomic_helper_check_plane_state(&plane_state, &crtc_state,
137						  min_scale, max_scale,
138						  can_position,
139						  can_update_disabled);
140	if (ret)
141		return ret;
142
143	*src = plane_state.src;
144	*dst = plane_state.dst;
145	*visible = plane_state.visible;
146
147	return 0;
148}
149
150/**
151 * drm_plane_helper_update_primary - Helper for updating primary planes
152 * @plane: plane to update
153 * @crtc: the plane's new CRTC
154 * @fb: the plane's new framebuffer
155 * @crtc_x: x coordinate within CRTC
156 * @crtc_y: y coordinate within CRTC
157 * @crtc_w: width coordinate within CRTC
158 * @crtc_h: height coordinate within CRTC
159 * @src_x: x coordinate within source
160 * @src_y: y coordinate within source
161 * @src_w: width coordinate within source
162 * @src_h: height coordinate within source
163 * @ctx: modeset locking context
164 *
165 * This helper validates the given parameters and updates the primary plane.
166 *
167 * This function is only useful for non-atomic modesetting. Don't use
168 * it in new drivers.
169 *
170 * Returns:
171 * Zero on success, or an errno code otherwise.
172 */
173int drm_plane_helper_update_primary(struct drm_plane *plane, struct drm_crtc *crtc,
174				    struct drm_framebuffer *fb,
175				    int crtc_x, int crtc_y,
176				    unsigned int crtc_w, unsigned int crtc_h,
177				    uint32_t src_x, uint32_t src_y,
178				    uint32_t src_w, uint32_t src_h,
179				    struct drm_modeset_acquire_ctx *ctx)
180{
181	struct drm_mode_set set = {
182		.crtc = crtc,
183		.fb = fb,
184		.mode = &crtc->mode,
185		.x = src_x >> 16,
186		.y = src_y >> 16,
187	};
188	struct drm_rect src = {
189		.x1 = src_x,
190		.y1 = src_y,
191		.x2 = src_x + src_w,
192		.y2 = src_y + src_h,
193	};
194	struct drm_rect dest = {
195		.x1 = crtc_x,
196		.y1 = crtc_y,
197		.x2 = crtc_x + crtc_w,
198		.y2 = crtc_y + crtc_h,
199	};
200	struct drm_device *dev = plane->dev;
201	struct drm_connector **connector_list;
202	int num_connectors, ret;
203	bool visible;
204
205	if (drm_WARN_ON_ONCE(dev, drm_drv_uses_atomic_modeset(dev)))
206		return -EINVAL;
207
208	ret = drm_plane_helper_check_update(plane, crtc, fb,
209					    &src, &dest,
210					    DRM_MODE_ROTATE_0,
211					    DRM_PLANE_NO_SCALING,
212					    DRM_PLANE_NO_SCALING,
213					    false, false, &visible);
214	if (ret)
215		return ret;
216
217	if (!visible)
218		/*
219		 * Primary plane isn't visible.  Note that unless a driver
220		 * provides their own disable function, this will just
221		 * wind up returning -EINVAL to userspace.
222		 */
223		return plane->funcs->disable_plane(plane, ctx);
224
225	/* Find current connectors for CRTC */
226	num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
227	BUG_ON(num_connectors == 0);
228	connector_list = kcalloc(num_connectors, sizeof(*connector_list),
229				 GFP_KERNEL);
230	if (!connector_list)
231		return -ENOMEM;
232	get_connectors_for_crtc(crtc, connector_list, num_connectors);
233
234	set.connectors = connector_list;
235	set.num_connectors = num_connectors;
236
237	/*
238	 * We call set_config() directly here rather than using
239	 * drm_mode_set_config_internal.  We're reprogramming the same
240	 * connectors that were already in use, so we shouldn't need the extra
241	 * cross-CRTC fb refcounting to accommodate stealing connectors.
242	 * drm_mode_setplane() already handles the basic refcounting for the
243	 * framebuffers involved in this operation.
244	 */
245	ret = crtc->funcs->set_config(&set, ctx);
246
247	kfree(connector_list);
248	return ret;
249}
250EXPORT_SYMBOL(drm_plane_helper_update_primary);
251
252/**
253 * drm_plane_helper_disable_primary - Helper for disabling primary planes
254 * @plane: plane to disable
255 * @ctx: modeset locking context
256 *
257 * This helper returns an error when trying to disable the primary
258 * plane.
259 *
260 * This function is only useful for non-atomic modesetting. Don't use
261 * it in new drivers.
262 *
263 * Returns:
264 * An errno code.
265 */
266int drm_plane_helper_disable_primary(struct drm_plane *plane,
267				     struct drm_modeset_acquire_ctx *ctx)
268{
269	struct drm_device *dev = plane->dev;
270
271	drm_WARN_ON_ONCE(dev, drm_drv_uses_atomic_modeset(dev));
272
273	return -EINVAL;
274}
275EXPORT_SYMBOL(drm_plane_helper_disable_primary);
276
277/**
278 * drm_plane_helper_destroy() - Helper for primary plane destruction
279 * @plane: plane to destroy
280 *
281 * Provides a default plane destroy handler for primary planes.  This handler
282 * is called during CRTC destruction.  We disable the primary plane, remove
283 * it from the DRM plane list, and deallocate the plane structure.
284 */
285void drm_plane_helper_destroy(struct drm_plane *plane)
286{
287	drm_plane_cleanup(plane);
288	kfree(plane);
289}
290EXPORT_SYMBOL(drm_plane_helper_destroy);
291
292/**
293 * drm_plane_helper_atomic_check() - Helper to check plane atomic-state
294 * @plane: plane to check
295 * @state: atomic state object
296 *
297 * Provides a default plane-state check handler for planes whose atomic-state
298 * scale and positioning are not expected to change since the plane is always
299 * a fullscreen scanout buffer.
300 *
301 * This is often the case for the primary plane of simple framebuffers. See
302 * also drm_crtc_helper_atomic_check() for the respective CRTC-state check
303 * helper function.
304 *
305 * RETURNS:
306 * Zero on success, or an errno code otherwise.
307 */
308int drm_plane_helper_atomic_check(struct drm_plane *plane, struct drm_atomic_state *state)
309{
310	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state, plane);
311	struct drm_crtc *new_crtc = new_plane_state->crtc;
312	struct drm_crtc_state *new_crtc_state = NULL;
313
314	if (new_crtc)
315		new_crtc_state = drm_atomic_get_new_crtc_state(state, new_crtc);
316
317	return drm_atomic_helper_check_plane_state(new_plane_state, new_crtc_state,
318						   DRM_PLANE_NO_SCALING,
319						   DRM_PLANE_NO_SCALING,
320						   false, false);
321}
322EXPORT_SYMBOL(drm_plane_helper_atomic_check);