xref: /openbmc/linux/include/drm/drm_fb_helper.h (revision f4356947)
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_probe:
74 	 *
75 	 * Driver callback to allocate and initialize the fbdev info structure.
76 	 * Furthermore it also needs to allocate the DRM framebuffer used to
77 	 * back the fbdev.
78 	 *
79 	 * This callback is mandatory.
80 	 *
81 	 * RETURNS:
82 	 *
83 	 * The driver should return 0 on success and a negative error code on
84 	 * failure.
85 	 */
86 	int (*fb_probe)(struct drm_fb_helper *helper,
87 			struct drm_fb_helper_surface_size *sizes);
88 
89 	/**
90 	 * @fb_dirty:
91 	 *
92 	 * Driver callback to update the framebuffer memory. If set, fbdev
93 	 * emulation will invoke this callback in regular intervals after
94 	 * the framebuffer has been written.
95 	 *
96 	 * This callback is optional.
97 	 *
98 	 * Returns:
99 	 * 0 on success, or an error code otherwise.
100 	 */
101 	int (*fb_dirty)(struct drm_fb_helper *helper, struct drm_clip_rect *clip);
102 };
103 
104 /**
105  * struct drm_fb_helper - main structure to emulate fbdev on top of KMS
106  * @fb: Scanout framebuffer object
107  * @dev: DRM device
108  * @funcs: driver callbacks for fb helper
109  * @info: emulated fbdev device info struct
110  * @pseudo_palette: fake palette of 16 colors
111  * @damage_clip: clip rectangle used with deferred_io to accumulate damage to
112  *                the screen buffer
113  * @damage_lock: spinlock protecting @damage_clip
114  * @damage_work: worker used to flush the framebuffer
115  * @resume_work: worker used during resume if the console lock is already taken
116  *
117  * This is the main structure used by the fbdev helpers. Drivers supporting
118  * fbdev emulation should embedded this into their overall driver structure.
119  * Drivers must also fill out a &struct drm_fb_helper_funcs with a few
120  * operations.
121  */
122 struct drm_fb_helper {
123 	/**
124 	 * @client:
125 	 *
126 	 * DRM client used by the generic fbdev emulation.
127 	 */
128 	struct drm_client_dev client;
129 
130 	/**
131 	 * @buffer:
132 	 *
133 	 * Framebuffer used by the generic fbdev emulation.
134 	 */
135 	struct drm_client_buffer *buffer;
136 
137 	struct drm_framebuffer *fb;
138 	struct drm_device *dev;
139 	const struct drm_fb_helper_funcs *funcs;
140 	struct fb_info *info;
141 	u32 pseudo_palette[17];
142 	struct drm_clip_rect damage_clip;
143 	spinlock_t damage_lock;
144 	struct work_struct damage_work;
145 	struct work_struct resume_work;
146 
147 	/**
148 	 * @lock:
149 	 *
150 	 * Top-level FBDEV helper lock. This protects all internal data
151 	 * structures and lists, such as @connector_info and @crtc_info.
152 	 *
153 	 * FIXME: fbdev emulation locking is a mess and long term we want to
154 	 * protect all helper internal state with this lock as well as reduce
155 	 * core KMS locking as much as possible.
156 	 */
157 	struct mutex lock;
158 
159 	/**
160 	 * @kernel_fb_list:
161 	 *
162 	 * Entry on the global kernel_fb_helper_list, used for kgdb entry/exit.
163 	 */
164 	struct list_head kernel_fb_list;
165 
166 	/**
167 	 * @delayed_hotplug:
168 	 *
169 	 * A hotplug was received while fbdev wasn't in control of the DRM
170 	 * device, i.e. another KMS master was active. The output configuration
171 	 * needs to be reprobe when fbdev is in control again.
172 	 */
173 	bool delayed_hotplug;
174 
175 	/**
176 	 * @deferred_setup:
177 	 *
178 	 * If no outputs are connected (disconnected or unknown) the FB helper
179 	 * code will defer setup until at least one of the outputs shows up.
180 	 * This field keeps track of the status so that setup can be retried
181 	 * at every hotplug event until it succeeds eventually.
182 	 *
183 	 * Protected by @lock.
184 	 */
185 	bool deferred_setup;
186 
187 	/**
188 	 * @preferred_bpp:
189 	 *
190 	 * Temporary storage for the driver's preferred BPP setting passed to
191 	 * FB helper initialization. This needs to be tracked so that deferred
192 	 * FB helper setup can pass this on.
193 	 *
194 	 * See also: @deferred_setup
195 	 */
196 	int preferred_bpp;
197 
198 #ifdef CONFIG_FB_DEFERRED_IO
199 	/**
200 	 * @fbdefio:
201 	 *
202 	 * Temporary storage for the driver's FB deferred I/O handler. If the
203 	 * driver uses the DRM fbdev emulation layer, this is set by the core
204 	 * to a generic deferred I/O handler if a driver is preferring to use
205 	 * a shadow buffer.
206 	 */
207 	struct fb_deferred_io fbdefio;
208 #endif
209 };
210 
211 static inline struct drm_fb_helper *
212 drm_fb_helper_from_client(struct drm_client_dev *client)
213 {
214 	return container_of(client, struct drm_fb_helper, client);
215 }
216 
217 /**
218  * define DRM_FB_HELPER_DEFAULT_OPS - helper define for drm drivers
219  *
220  * Helper define to register default implementations of drm_fb_helper
221  * functions. To be used in struct fb_ops of drm drivers.
222  */
223 #define DRM_FB_HELPER_DEFAULT_OPS \
224 	.fb_check_var	= drm_fb_helper_check_var, \
225 	.fb_set_par	= drm_fb_helper_set_par, \
226 	.fb_setcmap	= drm_fb_helper_setcmap, \
227 	.fb_blank	= drm_fb_helper_blank, \
228 	.fb_pan_display	= drm_fb_helper_pan_display, \
229 	.fb_debug_enter = drm_fb_helper_debug_enter, \
230 	.fb_debug_leave = drm_fb_helper_debug_leave, \
231 	.fb_ioctl	= drm_fb_helper_ioctl
232 
233 #ifdef CONFIG_DRM_FBDEV_EMULATION
234 void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
235 			   unsigned int preferred_bpp,
236 			   const struct drm_fb_helper_funcs *funcs);
237 void drm_fb_helper_unprepare(struct drm_fb_helper *fb_helper);
238 int drm_fb_helper_init(struct drm_device *dev, struct drm_fb_helper *helper);
239 void drm_fb_helper_fini(struct drm_fb_helper *helper);
240 int drm_fb_helper_blank(int blank, struct fb_info *info);
241 int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
242 			      struct fb_info *info);
243 int drm_fb_helper_set_par(struct fb_info *info);
244 int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
245 			    struct fb_info *info);
246 
247 int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper);
248 
249 struct fb_info *drm_fb_helper_alloc_info(struct drm_fb_helper *fb_helper);
250 void drm_fb_helper_release_info(struct drm_fb_helper *fb_helper);
251 void drm_fb_helper_unregister_info(struct drm_fb_helper *fb_helper);
252 void drm_fb_helper_fill_info(struct fb_info *info,
253 			     struct drm_fb_helper *fb_helper,
254 			     struct drm_fb_helper_surface_size *sizes);
255 
256 void drm_fb_helper_deferred_io(struct fb_info *info, struct list_head *pagereflist);
257 
258 ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
259 			       size_t count, loff_t *ppos);
260 ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
261 				size_t count, loff_t *ppos);
262 
263 void drm_fb_helper_sys_fillrect(struct fb_info *info,
264 				const struct fb_fillrect *rect);
265 void drm_fb_helper_sys_copyarea(struct fb_info *info,
266 				const struct fb_copyarea *area);
267 void drm_fb_helper_sys_imageblit(struct fb_info *info,
268 				 const struct fb_image *image);
269 
270 ssize_t drm_fb_helper_cfb_read(struct fb_info *info, char __user *buf,
271 			       size_t count, loff_t *ppos);
272 ssize_t drm_fb_helper_cfb_write(struct fb_info *info, const char __user *buf,
273 				size_t count, loff_t *ppos);
274 
275 void drm_fb_helper_cfb_fillrect(struct fb_info *info,
276 				const struct fb_fillrect *rect);
277 void drm_fb_helper_cfb_copyarea(struct fb_info *info,
278 				const struct fb_copyarea *area);
279 void drm_fb_helper_cfb_imageblit(struct fb_info *info,
280 				 const struct fb_image *image);
281 
282 void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend);
283 void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
284 					bool suspend);
285 
286 int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info);
287 
288 int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
289 			unsigned long arg);
290 
291 int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper);
292 int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper);
293 int drm_fb_helper_debug_enter(struct fb_info *info);
294 int drm_fb_helper_debug_leave(struct fb_info *info);
295 
296 void drm_fb_helper_lastclose(struct drm_device *dev);
297 void drm_fb_helper_output_poll_changed(struct drm_device *dev);
298 #else
299 static inline void drm_fb_helper_prepare(struct drm_device *dev,
300 					 struct drm_fb_helper *helper,
301 					 unsigned int preferred_bpp,
302 					 const struct drm_fb_helper_funcs *funcs)
303 {
304 }
305 
306 static inline void drm_fb_helper_unprepare(struct drm_fb_helper *fb_helper)
307 {
308 }
309 
310 static inline int drm_fb_helper_init(struct drm_device *dev,
311 		       struct drm_fb_helper *helper)
312 {
313 	/* So drivers can use it to free the struct */
314 	helper->dev = dev;
315 	dev->fb_helper = helper;
316 
317 	return 0;
318 }
319 
320 static inline void drm_fb_helper_fini(struct drm_fb_helper *helper)
321 {
322 	if (helper && helper->dev)
323 		helper->dev->fb_helper = NULL;
324 }
325 
326 static inline int drm_fb_helper_blank(int blank, struct fb_info *info)
327 {
328 	return 0;
329 }
330 
331 static inline int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
332 					    struct fb_info *info)
333 {
334 	return 0;
335 }
336 
337 static inline int drm_fb_helper_set_par(struct fb_info *info)
338 {
339 	return 0;
340 }
341 
342 static inline int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
343 					  struct fb_info *info)
344 {
345 	return 0;
346 }
347 
348 static inline int
349 drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
350 {
351 	return 0;
352 }
353 
354 static inline struct fb_info *
355 drm_fb_helper_alloc_info(struct drm_fb_helper *fb_helper)
356 {
357 	return NULL;
358 }
359 
360 static inline void drm_fb_helper_release_info(struct drm_fb_helper *fb_helper)
361 {
362 }
363 
364 static inline void drm_fb_helper_unregister_info(struct drm_fb_helper *fb_helper)
365 {
366 }
367 
368 static inline void
369 drm_fb_helper_fill_info(struct fb_info *info,
370 			struct drm_fb_helper *fb_helper,
371 			struct drm_fb_helper_surface_size *sizes)
372 {
373 }
374 
375 static inline int drm_fb_helper_setcmap(struct fb_cmap *cmap,
376 					struct fb_info *info)
377 {
378 	return 0;
379 }
380 
381 static inline int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
382 				      unsigned long arg)
383 {
384 	return 0;
385 }
386 
387 static inline void drm_fb_helper_deferred_io(struct fb_info *info,
388 					     struct list_head *pagelist)
389 {
390 }
391 
392 static inline int drm_fb_helper_defio_init(struct drm_fb_helper *fb_helper)
393 {
394 	return -ENODEV;
395 }
396 
397 static inline ssize_t drm_fb_helper_sys_read(struct fb_info *info,
398 					     char __user *buf, size_t count,
399 					     loff_t *ppos)
400 {
401 	return -ENODEV;
402 }
403 
404 static inline ssize_t drm_fb_helper_sys_write(struct fb_info *info,
405 					      const char __user *buf,
406 					      size_t count, loff_t *ppos)
407 {
408 	return -ENODEV;
409 }
410 
411 static inline void drm_fb_helper_sys_fillrect(struct fb_info *info,
412 					      const struct fb_fillrect *rect)
413 {
414 }
415 
416 static inline void drm_fb_helper_sys_copyarea(struct fb_info *info,
417 					      const struct fb_copyarea *area)
418 {
419 }
420 
421 static inline void drm_fb_helper_sys_imageblit(struct fb_info *info,
422 					       const struct fb_image *image)
423 {
424 }
425 
426 static inline ssize_t drm_fb_helper_cfb_read(struct fb_info *info, char __user *buf,
427 					     size_t count, loff_t *ppos)
428 {
429 	return -ENODEV;
430 }
431 
432 static inline ssize_t drm_fb_helper_cfb_write(struct fb_info *info, const char __user *buf,
433 					      size_t count, loff_t *ppos)
434 {
435 	return -ENODEV;
436 }
437 
438 static inline void drm_fb_helper_cfb_fillrect(struct fb_info *info,
439 					      const struct fb_fillrect *rect)
440 {
441 }
442 
443 static inline void drm_fb_helper_cfb_copyarea(struct fb_info *info,
444 					      const struct fb_copyarea *area)
445 {
446 }
447 
448 static inline void drm_fb_helper_cfb_imageblit(struct fb_info *info,
449 					       const struct fb_image *image)
450 {
451 }
452 
453 static inline void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper,
454 					     bool suspend)
455 {
456 }
457 
458 static inline void
459 drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper, bool suspend)
460 {
461 }
462 
463 static inline int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
464 {
465 	return 0;
466 }
467 
468 static inline int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper)
469 {
470 	return 0;
471 }
472 
473 static inline int drm_fb_helper_debug_enter(struct fb_info *info)
474 {
475 	return 0;
476 }
477 
478 static inline int drm_fb_helper_debug_leave(struct fb_info *info)
479 {
480 	return 0;
481 }
482 
483 static inline void drm_fb_helper_lastclose(struct drm_device *dev)
484 {
485 }
486 
487 static inline void drm_fb_helper_output_poll_changed(struct drm_device *dev)
488 {
489 }
490 #endif
491 
492 #endif
493