drm_plane_helper.c

  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/export.h>
 27#include <linux/list.h>
 28
 29#include <drm/drm_atomic.h>
 30#include <drm/drm_atomic_helper.h>
 31#include <drm/drm_atomic_uapi.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 contains helpers to implement primary plane support on
 45 * 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 plane helpers share the function table structures with other helpers,
 56 * specifically also the atomic helpers. See &struct drm_plane_helper_funcs for
 57 * the details.
 58 */
 59
 60/*
 61 * Returns the connectors currently associated with a CRTC.  This function
 62 * should be called twice:  once with a NULL connector list to retrieve
 63 * the list size, and once with the properly allocated list to be filled in.
 64 */
 65static int get_connectors_for_crtc(struct drm_crtc *crtc,
 66				   struct drm_connector **connector_list,
 67				   int num_connectors)
 68{
 69	struct drm_device *dev = crtc->dev;
 70	struct drm_connector *connector;
 71	struct drm_connector_list_iter conn_iter;
 72	int count = 0;
 73
 74	/*
 75	 * Note: Once we change the plane hooks to more fine-grained locking we
 76	 * need to grab the connection_mutex here to be able to make these
 77	 * checks.
 78	 */
 79	WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
 80
 81	drm_connector_list_iter_begin(dev, &conn_iter);
 82	drm_for_each_connector_iter(connector, &conn_iter) {
 83		if (connector->encoder && connector->encoder->crtc == crtc) {
 84			if (connector_list != NULL && count < num_connectors)
 85				*(connector_list++) = connector;
 86
 87			count++;
 88		}
 89	}
 90	drm_connector_list_iter_end(&conn_iter);
 91
 92	return count;
 93}
 94
 95static int drm_plane_helper_check_update(struct drm_plane *plane,
 96					 struct drm_crtc *crtc,
 97					 struct drm_framebuffer *fb,
 98					 struct drm_rect *src,
 99					 struct drm_rect *dst,
100					 unsigned int rotation,
101					 int min_scale,
102					 int max_scale,
103					 bool can_position,
104					 bool can_update_disabled,
105					 bool *visible)
106{
107	struct drm_plane_state plane_state = {
108		.plane = plane,
109		.crtc = crtc,
110		.fb = fb,
111		.src_x = src->x1,
112		.src_y = src->y1,
113		.src_w = drm_rect_width(src),
114		.src_h = drm_rect_height(src),
115		.crtc_x = dst->x1,
116		.crtc_y = dst->y1,
117		.crtc_w = drm_rect_width(dst),
118		.crtc_h = drm_rect_height(dst),
119		.rotation = rotation,
120	};
121	struct drm_crtc_state crtc_state = {
122		.crtc = crtc,
123		.enable = crtc->enabled,
124		.mode = crtc->mode,
125	};
126	int ret;
127
128	ret = drm_atomic_helper_check_plane_state(&plane_state, &crtc_state,
129						  min_scale, max_scale,
130						  can_position,
131						  can_update_disabled);
132	if (ret)
133		return ret;
134
135	*src = plane_state.src;
136	*dst = plane_state.dst;
137	*visible = plane_state.visible;
138
139	return 0;
140}
141
142/**
143 * drm_plane_helper_update_primary - Helper for updating primary planes
144 * @plane: plane to update
145 * @crtc: the plane's new CRTC
146 * @fb: the plane's new framebuffer
147 * @crtc_x: x coordinate within CRTC
148 * @crtc_y: y coordinate within CRTC
149 * @crtc_w: width coordinate within CRTC
150 * @crtc_h: height coordinate within CRTC
151 * @src_x: x coordinate within source
152 * @src_y: y coordinate within source
153 * @src_w: width coordinate within source
154 * @src_h: height coordinate within source
155 * @ctx: modeset locking context
156 *
157 * This helper validates the given parameters and updates the primary plane.
158 *
159 * This function is only useful for non-atomic modesetting. Don't use
160 * it in new drivers.
161 *
162 * Returns:
163 * Zero on success, or an errno code otherwise.
164 */
165int drm_plane_helper_update_primary(struct drm_plane *plane, struct drm_crtc *crtc,
166				    struct drm_framebuffer *fb,
167				    int crtc_x, int crtc_y,
168				    unsigned int crtc_w, unsigned int crtc_h,
169				    uint32_t src_x, uint32_t src_y,
170				    uint32_t src_w, uint32_t src_h,
171				    struct drm_modeset_acquire_ctx *ctx)
172{
173	struct drm_mode_set set = {
174		.crtc = crtc,
175		.fb = fb,
176		.mode = &crtc->mode,
177		.x = src_x >> 16,
178		.y = src_y >> 16,
179	};
180	struct drm_rect src = {
181		.x1 = src_x,
182		.y1 = src_y,
183		.x2 = src_x + src_w,
184		.y2 = src_y + src_h,
185	};
186	struct drm_rect dest = {
187		.x1 = crtc_x,
188		.y1 = crtc_y,
189		.x2 = crtc_x + crtc_w,
190		.y2 = crtc_y + crtc_h,
191	};
192	struct drm_device *dev = plane->dev;
193	struct drm_connector **connector_list;
194	int num_connectors, ret;
195	bool visible;
196
197	if (drm_WARN_ON_ONCE(dev, drm_drv_uses_atomic_modeset(dev)))
198		return -EINVAL;
199
200	ret = drm_plane_helper_check_update(plane, crtc, fb,
201					    &src, &dest,
202					    DRM_MODE_ROTATE_0,
203					    DRM_PLANE_NO_SCALING,
204					    DRM_PLANE_NO_SCALING,
205					    false, false, &visible);
206	if (ret)
207		return ret;
208
209	if (!visible)
210		/*
211		 * Primary plane isn't visible.  Note that unless a driver
212		 * provides their own disable function, this will just
213		 * wind up returning -EINVAL to userspace.
214		 */
215		return plane->funcs->disable_plane(plane, ctx);
216
217	/* Find current connectors for CRTC */
218	num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
219	BUG_ON(num_connectors == 0);
220	connector_list = kcalloc(num_connectors, sizeof(*connector_list),
221				 GFP_KERNEL);
222	if (!connector_list)
223		return -ENOMEM;
224	get_connectors_for_crtc(crtc, connector_list, num_connectors);
225
226	set.connectors = connector_list;
227	set.num_connectors = num_connectors;
228
229	/*
230	 * We call set_config() directly here rather than using
231	 * drm_mode_set_config_internal.  We're reprogramming the same
232	 * connectors that were already in use, so we shouldn't need the extra
233	 * cross-CRTC fb refcounting to accommodate stealing connectors.
234	 * drm_mode_setplane() already handles the basic refcounting for the
235	 * framebuffers involved in this operation.
236	 */
237	ret = crtc->funcs->set_config(&set, ctx);
238
239	kfree(connector_list);
240	return ret;
241}
242EXPORT_SYMBOL(drm_plane_helper_update_primary);
243
244/**
245 * drm_plane_helper_disable_primary - Helper for disabling primary planes
246 * @plane: plane to disable
247 * @ctx: modeset locking context
248 *
249 * This helper returns an error when trying to disable the primary
250 * plane.
251 *
252 * This function is only useful for non-atomic modesetting. Don't use
253 * it in new drivers.
254 *
255 * Returns:
256 * An errno code.
257 */
258int drm_plane_helper_disable_primary(struct drm_plane *plane,
259				     struct drm_modeset_acquire_ctx *ctx)
260{
261	struct drm_device *dev = plane->dev;
262
263	drm_WARN_ON_ONCE(dev, drm_drv_uses_atomic_modeset(dev));
264
265	return -EINVAL;
266}
267EXPORT_SYMBOL(drm_plane_helper_disable_primary);
268
269/**
270 * drm_plane_helper_destroy() - Helper for primary plane destruction
271 * @plane: plane to destroy
272 *
273 * Provides a default plane destroy handler for primary planes.  This handler
274 * is called during CRTC destruction.  We disable the primary plane, remove
275 * it from the DRM plane list, and deallocate the plane structure.
276 */
277void drm_plane_helper_destroy(struct drm_plane *plane)
278{
279	drm_plane_cleanup(plane);
280	kfree(plane);
281}
282EXPORT_SYMBOL(drm_plane_helper_destroy);