xref: /linux/include/drm/drm_fb_helper.h (revision 41ff0b424d81b7936bc4d96e8957aa7f454c3527)
1 /*
2  * Copyright (c) 2006-2009 Red Hat Inc.
3  * Copyright (c) 2006-2008 Intel Corporation
4  * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
5  *
6  * DRM framebuffer helper functions
7  *
8  * Permission to use, copy, modify, distribute, and sell this software and its
9  * documentation for any purpose is hereby granted without fee, provided that
10  * the above copyright notice appear in all copies and that both that copyright
11  * notice and this permission notice appear in supporting documentation, and
12  * that the name of the copyright holders not be used in advertising or
13  * publicity pertaining to distribution of the software without specific,
14  * written prior permission.  The copyright holders make no representations
15  * about the suitability of this software for any purpose.  It is provided "as
16  * is" without express or implied warranty.
17  *
18  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
19  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
20  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
21  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
22  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
23  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
24  * OF THIS SOFTWARE.
25  *
26  * Authors:
27  *      Dave Airlie <airlied@linux.ie>
28  *      Jesse Barnes <jesse.barnes@intel.com>
29  */
30 #ifndef DRM_FB_HELPER_H
31 #define DRM_FB_HELPER_H
32 
33 struct drm_clip_rect;
34 struct drm_fb_helper;
35 
36 #include <linux/fb.h>
37 
38 #include <drm/drm_client.h>
39 
40 /**
41  * struct drm_fb_helper_surface_size - describes fbdev size and scanout surface size
42  * @fb_width: fbdev width
43  * @fb_height: fbdev height
44  * @surface_width: scanout buffer width
45  * @surface_height: scanout buffer height
46  * @surface_bpp: scanout buffer bpp
47  * @surface_depth: scanout buffer depth
48  *
49  * Note that the scanout surface width/height may be larger than the fbdev
50  * width/height.  In case of multiple displays, the scanout surface is sized
51  * according to the largest width/height (so it is large enough for all CRTCs
52  * to scanout).  But the fbdev width/height is sized to the minimum width/
53  * height of all the displays.  This ensures that fbcon fits on the smallest
54  * of the attached displays. fb_width/fb_height is used by
55  * drm_fb_helper_fill_info() to fill out the &fb_info.var structure.
56  */
57 struct drm_fb_helper_surface_size {
58 	u32 fb_width;
59 	u32 fb_height;
60 	u32 surface_width;
61 	u32 surface_height;
62 	u32 surface_bpp;
63 	u32 surface_depth;
64 };
65 
66 /**
67  * struct drm_fb_helper_funcs - driver callbacks for the fbdev emulation library
68  *
69  * Driver callbacks used by the fbdev emulation helper library.
70  */
71 struct drm_fb_helper_funcs {
72 	/**
73 	 * @fb_dirty:
74 	 *
75 	 * Driver callback to update the framebuffer memory. If set, fbdev
76 	 * emulation will invoke this callback in regular intervals after
77 	 * the framebuffer has been written.
78 	 *
79 	 * This callback is optional.
80 	 *
81 	 * Returns:
82 	 * 0 on success, or an error code otherwise.
83 	 */
84 	int (*fb_dirty)(struct drm_fb_helper *helper, struct drm_clip_rect *clip);
85 
86 	/**
87 	 * @fb_restore:
88 	 *
89 	 * Driver callback to restore internal fbdev state. If set, fbdev
90 	 * emulation will invoke this callback after restoring the display
91 	 * mode.
92 	 *
93 	 * Only for i915. Do not use in new code.
94 	 *
95 	 * TODO: Fix i915 to not require this callback.
96 	 */
97 	void (*fb_restore)(struct drm_fb_helper *helper);
98 
99 	/**
100 	 * @fb_set_suspend:
101 	 *
102 	 * Driver callback to suspend or resume, if set, fbdev emulation will
103 	 * invoke this callback during suspend and resume. Driver should call
104 	 * fb_set_suspend() from their implementation. If not set, fbdev
105 	 * emulation will invoke fb_set_suspend() directly.
106 	 *
107 	 * Only for i915. Do not use in new code.
108 	 *
109 	 * TODO: Fix i915 to not require this callback.
110 	 */
111 	void (*fb_set_suspend)(struct drm_fb_helper *helper, bool suspend);
112 };
113 
114 /**
115  * struct drm_fb_helper - main structure to emulate fbdev on top of KMS
116  * @fb: Scanout framebuffer object
117  * @dev: DRM device
118  * @funcs: driver callbacks for fb helper
119  * @info: emulated fbdev device info struct
120  * @pseudo_palette: fake palette of 16 colors
121  * @damage_clip: clip rectangle used with deferred_io to accumulate damage to
122  *                the screen buffer
123  * @damage_lock: spinlock protecting @damage_clip
124  * @damage_work: worker used to flush the framebuffer
125  * @resume_work: worker used during resume if the console lock is already taken
126  *
127  * This is the main structure used by the fbdev helpers. Drivers supporting
128  * fbdev emulation should embedded this into their overall driver structure.
129  * Drivers must also fill out a &struct drm_fb_helper_funcs with a few
130  * operations.
131  */
132 struct drm_fb_helper {
133 	/**
134 	 * @client:
135 	 *
136 	 * DRM client used by the generic fbdev emulation.
137 	 */
138 	struct drm_client_dev client;
139 
140 	/**
141 	 * @buffer:
142 	 *
143 	 * Framebuffer used by the generic fbdev emulation.
144 	 */
145 	struct drm_client_buffer *buffer;
146 
147 	struct drm_framebuffer *fb;
148 	struct drm_device *dev;
149 	const struct drm_fb_helper_funcs *funcs;
150 	struct fb_info *info;
151 	u32 pseudo_palette[17];
152 	struct drm_clip_rect damage_clip;
153 	spinlock_t damage_lock;
154 	struct work_struct damage_work;
155 	struct work_struct resume_work;
156 
157 	/**
158 	 * @lock:
159 	 *
160 	 * Top-level FBDEV helper lock. This protects all internal data
161 	 * structures and lists, such as @connector_info and @crtc_info.
162 	 *
163 	 * FIXME: fbdev emulation locking is a mess and long term we want to
164 	 * protect all helper internal state with this lock as well as reduce
165 	 * core KMS locking as much as possible.
166 	 */
167 	struct mutex lock;
168 
169 	/**
170 	 * @kernel_fb_list:
171 	 *
172 	 * Entry on the global kernel_fb_helper_list, used for kgdb entry/exit.
173 	 */
174 	struct list_head kernel_fb_list;
175 
176 	/**
177 	 * @delayed_hotplug:
178 	 *
179 	 * A hotplug was received while fbdev wasn't in control of the DRM
180 	 * device, i.e. another KMS master was active. The output configuration
181 	 * needs to be reprobe when fbdev is in control again.
182 	 */
183 	bool delayed_hotplug;
184 
185 	/**
186 	 * @deferred_setup:
187 	 *
188 	 * If no outputs are connected (disconnected or unknown) the FB helper
189 	 * code will defer setup until at least one of the outputs shows up.
190 	 * This field keeps track of the status so that setup can be retried
191 	 * at every hotplug event until it succeeds eventually.
192 	 *
193 	 * Protected by @lock.
194 	 */
195 	bool deferred_setup;
196 
197 	/**
198 	 * @preferred_bpp:
199 	 *
200 	 * Temporary storage for the driver's preferred BPP setting passed to
201 	 * FB helper initialization. This needs to be tracked so that deferred
202 	 * FB helper setup can pass this on.
203 	 *
204 	 * See also: @deferred_setup
205 	 */
206 	int preferred_bpp;
207 
208 #ifdef CONFIG_FB_DEFERRED_IO
209 	/**
210 	 * @fbdefio:
211 	 *
212 	 * Temporary storage for the driver's FB deferred I/O handler. If the
213 	 * driver uses the DRM fbdev emulation layer, this is set by the core
214 	 * to a generic deferred I/O handler if a driver is preferring to use
215 	 * a shadow buffer.
216 	 */
217 	struct fb_deferred_io fbdefio;
218 #endif
219 };
220 
221 static inline struct drm_fb_helper *
222 drm_fb_helper_from_client(struct drm_client_dev *client)
223 {
224 	return container_of(client, struct drm_fb_helper, client);
225 }
226 
227 /**
228  * define DRM_FB_HELPER_DEFAULT_OPS - helper define for drm drivers
229  *
230  * Helper define to register default implementations of drm_fb_helper
231  * functions. To be used in struct fb_ops of drm drivers.
232  */
233 #define DRM_FB_HELPER_DEFAULT_OPS \
234 	.fb_check_var	= drm_fb_helper_check_var, \
235 	.fb_set_par	= drm_fb_helper_set_par, \
236 	.fb_setcmap	= drm_fb_helper_setcmap, \
237 	.fb_blank	= drm_fb_helper_blank, \
238 	.fb_pan_display	= drm_fb_helper_pan_display, \
239 	.fb_debug_enter = drm_fb_helper_debug_enter, \
240 	.fb_debug_leave = drm_fb_helper_debug_leave, \
241 	.fb_ioctl	= drm_fb_helper_ioctl
242 
243 #ifdef CONFIG_DRM_FBDEV_EMULATION
244 void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
245 			   unsigned int preferred_bpp,
246 			   const struct drm_fb_helper_funcs *funcs);
247 void drm_fb_helper_unprepare(struct drm_fb_helper *fb_helper);
248 int drm_fb_helper_init(struct drm_device *dev, struct drm_fb_helper *helper);
249 void drm_fb_helper_fini(struct drm_fb_helper *helper);
250 int drm_fb_helper_blank(int blank, struct fb_info *info);
251 int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
252 			      struct fb_info *info);
253 int drm_fb_helper_set_par(struct fb_info *info);
254 int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
255 			    struct fb_info *info);
256 
257 int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper);
258 
259 struct fb_info *drm_fb_helper_alloc_info(struct drm_fb_helper *fb_helper);
260 void drm_fb_helper_release_info(struct drm_fb_helper *fb_helper);
261 void drm_fb_helper_unregister_info(struct drm_fb_helper *fb_helper);
262 void drm_fb_helper_fill_info(struct fb_info *info,
263 			     struct drm_fb_helper *fb_helper,
264 			     struct drm_fb_helper_surface_size *sizes);
265 
266 void drm_fb_helper_damage_range(struct fb_info *info, off_t off, size_t len);
267 void drm_fb_helper_damage_area(struct fb_info *info, u32 x, u32 y, u32 width, u32 height);
268 
269 #ifdef CONFIG_FB_DEFERRED_IO
270 void drm_fb_helper_deferred_io(struct fb_info *info, struct list_head *pagereflist);
271 #endif
272 
273 void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend);
274 void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
275 					bool suspend);
276 
277 int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info);
278 
279 int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
280 			unsigned long arg);
281 
282 int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper);
283 int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper);
284 int drm_fb_helper_debug_enter(struct fb_info *info);
285 int drm_fb_helper_debug_leave(struct fb_info *info);
286 void drm_fb_helper_lastclose(struct drm_device *dev);
287 #else
288 static inline void drm_fb_helper_prepare(struct drm_device *dev,
289 					 struct drm_fb_helper *helper,
290 					 unsigned int preferred_bpp,
291 					 const struct drm_fb_helper_funcs *funcs)
292 {
293 }
294 
295 static inline void drm_fb_helper_unprepare(struct drm_fb_helper *fb_helper)
296 {
297 }
298 
299 static inline int drm_fb_helper_init(struct drm_device *dev,
300 		       struct drm_fb_helper *helper)
301 {
302 	/* So drivers can use it to free the struct */
303 	helper->dev = dev;
304 	dev->fb_helper = helper;
305 
306 	return 0;
307 }
308 
309 static inline void drm_fb_helper_fini(struct drm_fb_helper *helper)
310 {
311 	if (helper && helper->dev)
312 		helper->dev->fb_helper = NULL;
313 }
314 
315 static inline int drm_fb_helper_blank(int blank, struct fb_info *info)
316 {
317 	return 0;
318 }
319 
320 static inline int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
321 					    struct fb_info *info)
322 {
323 	return 0;
324 }
325 
326 static inline int drm_fb_helper_set_par(struct fb_info *info)
327 {
328 	return 0;
329 }
330 
331 static inline int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
332 					  struct fb_info *info)
333 {
334 	return 0;
335 }
336 
337 static inline int
338 drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
339 {
340 	return 0;
341 }
342 
343 static inline struct fb_info *
344 drm_fb_helper_alloc_info(struct drm_fb_helper *fb_helper)
345 {
346 	return NULL;
347 }
348 
349 static inline void drm_fb_helper_release_info(struct drm_fb_helper *fb_helper)
350 {
351 }
352 
353 static inline void drm_fb_helper_unregister_info(struct drm_fb_helper *fb_helper)
354 {
355 }
356 
357 static inline void
358 drm_fb_helper_fill_info(struct fb_info *info,
359 			struct drm_fb_helper *fb_helper,
360 			struct drm_fb_helper_surface_size *sizes)
361 {
362 }
363 
364 static inline int drm_fb_helper_setcmap(struct fb_cmap *cmap,
365 					struct fb_info *info)
366 {
367 	return 0;
368 }
369 
370 static inline int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
371 				      unsigned long arg)
372 {
373 	return 0;
374 }
375 
376 #ifdef CONFIG_FB_DEFERRED_IO
377 static inline void drm_fb_helper_deferred_io(struct fb_info *info,
378 					     struct list_head *pagelist)
379 {
380 }
381 #endif
382 
383 static inline void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper,
384 					     bool suspend)
385 {
386 }
387 
388 static inline void
389 drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper, bool suspend)
390 {
391 }
392 
393 static inline int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
394 {
395 	return 0;
396 }
397 
398 static inline int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper)
399 {
400 	return 0;
401 }
402 
403 static inline int drm_fb_helper_debug_enter(struct fb_info *info)
404 {
405 	return 0;
406 }
407 
408 static inline int drm_fb_helper_debug_leave(struct fb_info *info)
409 {
410 	return 0;
411 }
412 
413 static inline void drm_fb_helper_lastclose(struct drm_device *dev)
414 {
415 }
416 #endif
417 
418 #endif
419