xref: /openbmc/linux/include/drm/drm_fb_helper.h (revision 47ebd031)
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 	/**
199 	 * @hint_leak_smem_start:
200 	 *
201 	 * Hint to the fbdev emulation to store the framebuffer's physical
202 	 * address in struct &fb_info.fix.smem_start. If the hint is unset,
203 	 * the smem_start field should always be cleared to zero.
204 	 */
205 	bool hint_leak_smem_start;
206 
207 #ifdef CONFIG_FB_DEFERRED_IO
208 	/**
209 	 * @fbdefio:
210 	 *
211 	 * Temporary storage for the driver's FB deferred I/O handler. If the
212 	 * driver uses the DRM fbdev emulation layer, this is set by the core
213 	 * to a generic deferred I/O handler if a driver is preferring to use
214 	 * a shadow buffer.
215 	 */
216 	struct fb_deferred_io fbdefio;
217 #endif
218 };
219 
220 static inline struct drm_fb_helper *
221 drm_fb_helper_from_client(struct drm_client_dev *client)
222 {
223 	return container_of(client, struct drm_fb_helper, client);
224 }
225 
226 /**
227  * define DRM_FB_HELPER_DEFAULT_OPS - helper define for drm drivers
228  *
229  * Helper define to register default implementations of drm_fb_helper
230  * functions. To be used in struct fb_ops of drm drivers.
231  */
232 #define DRM_FB_HELPER_DEFAULT_OPS \
233 	.fb_check_var	= drm_fb_helper_check_var, \
234 	.fb_set_par	= drm_fb_helper_set_par, \
235 	.fb_setcmap	= drm_fb_helper_setcmap, \
236 	.fb_blank	= drm_fb_helper_blank, \
237 	.fb_pan_display	= drm_fb_helper_pan_display, \
238 	.fb_debug_enter = drm_fb_helper_debug_enter, \
239 	.fb_debug_leave = drm_fb_helper_debug_leave, \
240 	.fb_ioctl	= drm_fb_helper_ioctl
241 
242 #ifdef CONFIG_DRM_FBDEV_EMULATION
243 void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
244 			   unsigned int preferred_bpp,
245 			   const struct drm_fb_helper_funcs *funcs);
246 void drm_fb_helper_unprepare(struct drm_fb_helper *fb_helper);
247 int drm_fb_helper_init(struct drm_device *dev, struct drm_fb_helper *helper);
248 void drm_fb_helper_fini(struct drm_fb_helper *helper);
249 int drm_fb_helper_blank(int blank, struct fb_info *info);
250 int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
251 			      struct fb_info *info);
252 int drm_fb_helper_set_par(struct fb_info *info);
253 int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
254 			    struct fb_info *info);
255 
256 int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper);
257 
258 struct fb_info *drm_fb_helper_alloc_info(struct drm_fb_helper *fb_helper);
259 void drm_fb_helper_unregister_info(struct drm_fb_helper *fb_helper);
260 void drm_fb_helper_fill_info(struct fb_info *info,
261 			     struct drm_fb_helper *fb_helper,
262 			     struct drm_fb_helper_surface_size *sizes);
263 
264 void drm_fb_helper_deferred_io(struct fb_info *info, struct list_head *pagereflist);
265 
266 ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
267 			       size_t count, loff_t *ppos);
268 ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
269 				size_t count, loff_t *ppos);
270 
271 void drm_fb_helper_sys_fillrect(struct fb_info *info,
272 				const struct fb_fillrect *rect);
273 void drm_fb_helper_sys_copyarea(struct fb_info *info,
274 				const struct fb_copyarea *area);
275 void drm_fb_helper_sys_imageblit(struct fb_info *info,
276 				 const struct fb_image *image);
277 
278 ssize_t drm_fb_helper_cfb_read(struct fb_info *info, char __user *buf,
279 			       size_t count, loff_t *ppos);
280 ssize_t drm_fb_helper_cfb_write(struct fb_info *info, const char __user *buf,
281 				size_t count, loff_t *ppos);
282 
283 void drm_fb_helper_cfb_fillrect(struct fb_info *info,
284 				const struct fb_fillrect *rect);
285 void drm_fb_helper_cfb_copyarea(struct fb_info *info,
286 				const struct fb_copyarea *area);
287 void drm_fb_helper_cfb_imageblit(struct fb_info *info,
288 				 const struct fb_image *image);
289 
290 void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend);
291 void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
292 					bool suspend);
293 
294 int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info);
295 
296 int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
297 			unsigned long arg);
298 
299 int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper);
300 int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper);
301 int drm_fb_helper_debug_enter(struct fb_info *info);
302 int drm_fb_helper_debug_leave(struct fb_info *info);
303 
304 void drm_fb_helper_lastclose(struct drm_device *dev);
305 void drm_fb_helper_output_poll_changed(struct drm_device *dev);
306 #else
307 static inline void drm_fb_helper_prepare(struct drm_device *dev,
308 					 struct drm_fb_helper *helper,
309 					 unsigned int preferred_bpp,
310 					 const struct drm_fb_helper_funcs *funcs)
311 {
312 }
313 
314 static inline void drm_fb_helper_unprepare(struct drm_fb_helper *fb_helper)
315 {
316 }
317 
318 static inline int drm_fb_helper_init(struct drm_device *dev,
319 		       struct drm_fb_helper *helper)
320 {
321 	/* So drivers can use it to free the struct */
322 	helper->dev = dev;
323 	dev->fb_helper = helper;
324 
325 	return 0;
326 }
327 
328 static inline void drm_fb_helper_fini(struct drm_fb_helper *helper)
329 {
330 	if (helper && helper->dev)
331 		helper->dev->fb_helper = NULL;
332 }
333 
334 static inline int drm_fb_helper_blank(int blank, struct fb_info *info)
335 {
336 	return 0;
337 }
338 
339 static inline int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
340 					    struct fb_info *info)
341 {
342 	return 0;
343 }
344 
345 static inline int drm_fb_helper_set_par(struct fb_info *info)
346 {
347 	return 0;
348 }
349 
350 static inline int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
351 					  struct fb_info *info)
352 {
353 	return 0;
354 }
355 
356 static inline int
357 drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
358 {
359 	return 0;
360 }
361 
362 static inline struct fb_info *
363 drm_fb_helper_alloc_info(struct drm_fb_helper *fb_helper)
364 {
365 	return NULL;
366 }
367 
368 static inline void drm_fb_helper_unregister_info(struct drm_fb_helper *fb_helper)
369 {
370 }
371 
372 static inline void
373 drm_fb_helper_fill_info(struct fb_info *info,
374 			struct drm_fb_helper *fb_helper,
375 			struct drm_fb_helper_surface_size *sizes)
376 {
377 }
378 
379 static inline int drm_fb_helper_setcmap(struct fb_cmap *cmap,
380 					struct fb_info *info)
381 {
382 	return 0;
383 }
384 
385 static inline int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
386 				      unsigned long arg)
387 {
388 	return 0;
389 }
390 
391 static inline void drm_fb_helper_deferred_io(struct fb_info *info,
392 					     struct list_head *pagelist)
393 {
394 }
395 
396 static inline int drm_fb_helper_defio_init(struct drm_fb_helper *fb_helper)
397 {
398 	return -ENODEV;
399 }
400 
401 static inline ssize_t drm_fb_helper_sys_read(struct fb_info *info,
402 					     char __user *buf, size_t count,
403 					     loff_t *ppos)
404 {
405 	return -ENODEV;
406 }
407 
408 static inline ssize_t drm_fb_helper_sys_write(struct fb_info *info,
409 					      const char __user *buf,
410 					      size_t count, loff_t *ppos)
411 {
412 	return -ENODEV;
413 }
414 
415 static inline void drm_fb_helper_sys_fillrect(struct fb_info *info,
416 					      const struct fb_fillrect *rect)
417 {
418 }
419 
420 static inline void drm_fb_helper_sys_copyarea(struct fb_info *info,
421 					      const struct fb_copyarea *area)
422 {
423 }
424 
425 static inline void drm_fb_helper_sys_imageblit(struct fb_info *info,
426 					       const struct fb_image *image)
427 {
428 }
429 
430 static inline ssize_t drm_fb_helper_cfb_read(struct fb_info *info, char __user *buf,
431 					     size_t count, loff_t *ppos)
432 {
433 	return -ENODEV;
434 }
435 
436 static inline ssize_t drm_fb_helper_cfb_write(struct fb_info *info, const char __user *buf,
437 					      size_t count, loff_t *ppos)
438 {
439 	return -ENODEV;
440 }
441 
442 static inline void drm_fb_helper_cfb_fillrect(struct fb_info *info,
443 					      const struct fb_fillrect *rect)
444 {
445 }
446 
447 static inline void drm_fb_helper_cfb_copyarea(struct fb_info *info,
448 					      const struct fb_copyarea *area)
449 {
450 }
451 
452 static inline void drm_fb_helper_cfb_imageblit(struct fb_info *info,
453 					       const struct fb_image *image)
454 {
455 }
456 
457 static inline void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper,
458 					     bool suspend)
459 {
460 }
461 
462 static inline void
463 drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper, bool suspend)
464 {
465 }
466 
467 static inline int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
468 {
469 	return 0;
470 }
471 
472 static inline int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper)
473 {
474 	return 0;
475 }
476 
477 static inline int drm_fb_helper_debug_enter(struct fb_info *info)
478 {
479 	return 0;
480 }
481 
482 static inline int drm_fb_helper_debug_leave(struct fb_info *info)
483 {
484 	return 0;
485 }
486 
487 static inline void drm_fb_helper_lastclose(struct drm_device *dev)
488 {
489 }
490 
491 static inline void drm_fb_helper_output_poll_changed(struct drm_device *dev)
492 {
493 }
494 #endif
495 
496 #endif
497