2 * Copyright (C) 2014 Intel Corporation
4 * DRM universal plane helper functions
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26 #include <linux/list.h>
28 #include <drm/drm_plane_helper.h>
29 #include <drm/drm_rect.h>
30 #include <drm/drm_plane_helper.h>
32 #define SUBPIXEL_MASK 0xffff
35 * This is the minimal list of formats that seem to be safe for modeset use
36 * with all current DRM drivers. Most hardware can actually support more
37 * formats than this and drivers may specify a more accurate list when
38 * creating the primary plane. However drivers that still call
39 * drm_plane_init() will use this minimal format list as the default.
41 static const uint32_t safe_modeset_formats[] = {
47 * Returns the connectors currently associated with a CRTC. This function
48 * should be called twice: once with a NULL connector list to retrieve
49 * the list size, and once with the properly allocated list to be filled in.
51 static int get_connectors_for_crtc(struct drm_crtc *crtc,
52 struct drm_connector **connector_list,
55 struct drm_device *dev = crtc->dev;
56 struct drm_connector *connector;
60 * Note: Once we change the plane hooks to more fine-grained locking we
61 * need to grab the connection_mutex here to be able to make these
64 WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
66 list_for_each_entry(connector, &dev->mode_config.connector_list, head)
67 if (connector->encoder && connector->encoder->crtc == crtc) {
68 if (connector_list != NULL && count < num_connectors)
69 *(connector_list++) = connector;
78 * drm_plane_helper_check_update() - Check plane update for validity
79 * @plane: plane object to update
80 * @crtc: owning CRTC of owning plane
81 * @fb: framebuffer to flip onto plane
82 * @src: source coordinates in 16.16 fixed point
83 * @dest: integer destination coordinates
84 * @clip: integer clipping coordinates
85 * @min_scale: minimum @src:@dest scaling factor in 16.16 fixed point
86 * @max_scale: maximum @src:@dest scaling factor in 16.16 fixed point
87 * @can_position: is it legal to position the plane such that it
88 * doesn't cover the entire crtc? This will generally
89 * only be false for primary planes.
90 * @can_update_disabled: can the plane be updated while the crtc
92 * @visible: output parameter indicating whether plane is still visible after
95 * Checks that a desired plane update is valid. Drivers that provide
96 * their own plane handling rather than helper-provided implementations may
97 * still wish to call this function to avoid duplication of error checking
101 * Zero if update appears valid, error code on failure
103 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 *dest,
108 const struct drm_rect *clip,
112 bool can_update_disabled,
117 if (!crtc->enabled && !can_update_disabled) {
118 DRM_DEBUG_KMS("Cannot update plane of a disabled CRTC.\n");
123 hscale = drm_rect_calc_hscale(src, dest, min_scale, max_scale);
124 vscale = drm_rect_calc_vscale(src, dest, min_scale, max_scale);
125 if (hscale < 0 || vscale < 0) {
126 DRM_DEBUG_KMS("Invalid scaling of plane\n");
130 *visible = drm_rect_clip_scaled(src, dest, clip, hscale, vscale);
133 * Plane isn't visible; some drivers can handle this
134 * so we just return success here. Drivers that can't
135 * (including those that use the primary plane helper's
136 * update function) will return an error from their
137 * update_plane handler.
141 if (!can_position && !drm_rect_equals(dest, clip)) {
142 DRM_DEBUG_KMS("Plane must cover entire CRTC\n");
148 EXPORT_SYMBOL(drm_plane_helper_check_update);
151 * drm_primary_helper_update() - Helper for primary plane update
152 * @plane: plane object to update
153 * @crtc: owning CRTC of owning plane
154 * @fb: framebuffer to flip onto plane
155 * @crtc_x: x offset of primary plane on crtc
156 * @crtc_y: y offset of primary plane on crtc
157 * @crtc_w: width of primary plane rectangle on crtc
158 * @crtc_h: height of primary plane rectangle on crtc
159 * @src_x: x offset of @fb for panning
160 * @src_y: y offset of @fb for panning
161 * @src_w: width of source rectangle in @fb
162 * @src_h: height of source rectangle in @fb
164 * Provides a default plane update handler for primary planes. This is handler
165 * is called in response to a userspace SetPlane operation on the plane with a
166 * non-NULL framebuffer. We call the driver's modeset handler to update the
169 * SetPlane() on a primary plane of a disabled CRTC is not supported, and will
172 * Note that we make some assumptions about hardware limitations that may not be
173 * true for all hardware --
174 * 1) Primary plane cannot be repositioned.
175 * 2) Primary plane cannot be scaled.
176 * 3) Primary plane must cover the entire CRTC.
177 * 4) Subpixel positioning is not supported.
178 * Drivers for hardware that don't have these restrictions can provide their
179 * own implementation rather than using this helper.
182 * Zero on success, error code on failure
184 int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
185 struct drm_framebuffer *fb,
186 int crtc_x, int crtc_y,
187 unsigned int crtc_w, unsigned int crtc_h,
188 uint32_t src_x, uint32_t src_y,
189 uint32_t src_w, uint32_t src_h)
191 struct drm_mode_set set = {
198 struct drm_rect src = {
204 struct drm_rect dest = {
207 .x2 = crtc_x + crtc_w,
208 .y2 = crtc_y + crtc_h,
210 const struct drm_rect clip = {
211 .x2 = crtc->mode.hdisplay,
212 .y2 = crtc->mode.vdisplay,
214 struct drm_connector **connector_list;
215 int num_connectors, ret;
218 ret = drm_plane_helper_check_update(plane, crtc, fb,
220 DRM_PLANE_HELPER_NO_SCALING,
221 DRM_PLANE_HELPER_NO_SCALING,
222 false, false, &visible);
228 * Primary plane isn't visible. Note that unless a driver
229 * provides their own disable function, this will just
230 * wind up returning -EINVAL to userspace.
232 return plane->funcs->disable_plane(plane);
234 /* Find current connectors for CRTC */
235 num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
236 BUG_ON(num_connectors == 0);
237 connector_list = kzalloc(num_connectors * sizeof(*connector_list),
241 get_connectors_for_crtc(crtc, connector_list, num_connectors);
243 set.connectors = connector_list;
244 set.num_connectors = num_connectors;
247 * We call set_config() directly here rather than using
248 * drm_mode_set_config_internal. We're reprogramming the same
249 * connectors that were already in use, so we shouldn't need the extra
250 * cross-CRTC fb refcounting to accomodate stealing connectors.
251 * drm_mode_setplane() already handles the basic refcounting for the
252 * framebuffers involved in this operation.
254 ret = crtc->funcs->set_config(&set);
256 kfree(connector_list);
259 EXPORT_SYMBOL(drm_primary_helper_update);
262 * drm_primary_helper_disable() - Helper for primary plane disable
263 * @plane: plane to disable
265 * Provides a default plane disable handler for primary planes. This is handler
266 * is called in response to a userspace SetPlane operation on the plane with a
267 * NULL framebuffer parameter. It unconditionally fails the disable call with
268 * -EINVAL the only way to disable the primary plane without driver support is
269 * to disable the entier CRTC. Which does not match the plane ->disable hook.
271 * Note that some hardware may be able to disable the primary plane without
272 * disabling the whole CRTC. Drivers for such hardware should provide their
273 * own disable handler that disables just the primary plane (and they'll likely
274 * need to provide their own update handler as well to properly re-enable a
275 * disabled primary plane).
278 * Unconditionally returns -EINVAL.
280 int drm_primary_helper_disable(struct drm_plane *plane)
284 EXPORT_SYMBOL(drm_primary_helper_disable);
287 * drm_primary_helper_destroy() - Helper for primary plane destruction
288 * @plane: plane to destroy
290 * Provides a default plane destroy handler for primary planes. This handler
291 * is called during CRTC destruction. We disable the primary plane, remove
292 * it from the DRM plane list, and deallocate the plane structure.
294 void drm_primary_helper_destroy(struct drm_plane *plane)
296 drm_plane_cleanup(plane);
299 EXPORT_SYMBOL(drm_primary_helper_destroy);
301 const struct drm_plane_funcs drm_primary_helper_funcs = {
302 .update_plane = drm_primary_helper_update,
303 .disable_plane = drm_primary_helper_disable,
304 .destroy = drm_primary_helper_destroy,
306 EXPORT_SYMBOL(drm_primary_helper_funcs);
309 * drm_primary_helper_create_plane() - Create a generic primary plane
311 * @formats: pixel formats supported, or NULL for a default safe list
312 * @num_formats: size of @formats; ignored if @formats is NULL
314 * Allocates and initializes a primary plane that can be used with the primary
315 * plane helpers. Drivers that wish to use driver-specific plane structures or
316 * provide custom handler functions may perform their own allocation and
317 * initialization rather than calling this function.
319 struct drm_plane *drm_primary_helper_create_plane(struct drm_device *dev,
320 const uint32_t *formats,
323 struct drm_plane *primary;
326 primary = kzalloc(sizeof(*primary), GFP_KERNEL);
327 if (primary == NULL) {
328 DRM_DEBUG_KMS("Failed to allocate primary plane\n");
332 if (formats == NULL) {
333 formats = safe_modeset_formats;
334 num_formats = ARRAY_SIZE(safe_modeset_formats);
337 /* possible_crtc's will be filled in later by crtc_init */
338 ret = drm_plane_init(dev, primary, 0, &drm_primary_helper_funcs,
339 formats, num_formats,
340 DRM_PLANE_TYPE_PRIMARY);
348 EXPORT_SYMBOL(drm_primary_helper_create_plane);
351 * drm_crtc_init - Legacy CRTC initialization function
353 * @crtc: CRTC object to init
354 * @funcs: callbacks for the new CRTC
356 * Initialize a CRTC object with a default helper-provided primary plane and no
360 * Zero on success, error code on failure.
362 int drm_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
363 const struct drm_crtc_funcs *funcs)
365 struct drm_plane *primary;
367 primary = drm_primary_helper_create_plane(dev, NULL, 0);
368 return drm_crtc_init_with_planes(dev, crtc, primary, NULL, funcs);
370 EXPORT_SYMBOL(drm_crtc_init);