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_fb_helper;
34 
35 #include <drm/drm_crtc.h>
36 #include <linux/kgdb.h>
37 
38 enum mode_set_atomic {
39 	LEAVE_ATOMIC_MODE_SET,
40 	ENTER_ATOMIC_MODE_SET,
41 };
42 
43 struct drm_fb_offset {
44 	int x, y;
45 };
46 
47 struct drm_fb_helper_crtc {
48 	struct drm_mode_set mode_set;
49 	struct drm_display_mode *desired_mode;
50 	int x, y;
51 };
52 
53 /**
54  * struct drm_fb_helper_surface_size - describes fbdev size and scanout surface size
55  * @fb_width: fbdev width
56  * @fb_height: fbdev height
57  * @surface_width: scanout buffer width
58  * @surface_height: scanout buffer height
59  * @surface_bpp: scanout buffer bpp
60  * @surface_depth: scanout buffer depth
61  *
62  * Note that the scanout surface width/height may be larger than the fbdev
63  * width/height.  In case of multiple displays, the scanout surface is sized
64  * according to the largest width/height (so it is large enough for all CRTCs
65  * to scanout).  But the fbdev width/height is sized to the minimum width/
66  * height of all the displays.  This ensures that fbcon fits on the smallest
67  * of the attached displays.
68  *
69  * So what is passed to drm_fb_helper_fill_var() should be fb_width/fb_height,
70  * rather than the surface size.
71  */
72 struct drm_fb_helper_surface_size {
73 	u32 fb_width;
74 	u32 fb_height;
75 	u32 surface_width;
76 	u32 surface_height;
77 	u32 surface_bpp;
78 	u32 surface_depth;
79 };
80 
81 /**
82  * struct drm_fb_helper_funcs - driver callbacks for the fbdev emulation library
83  *
84  * Driver callbacks used by the fbdev emulation helper library.
85  */
86 struct drm_fb_helper_funcs {
87 	/**
88 	 * @gamma_set:
89 	 *
90 	 * Set the given gamma LUT register on the given CRTC.
91 	 *
92 	 * This callback is optional.
93 	 *
94 	 * FIXME:
95 	 *
96 	 * This callback is functionally redundant with the core gamma table
97 	 * support and simply exists because the fbdev hasn't yet been
98 	 * refactored to use the core gamma table interfaces.
99 	 */
100 	void (*gamma_set)(struct drm_crtc *crtc, u16 red, u16 green,
101 			  u16 blue, int regno);
102 	/**
103 	 * @gamma_get:
104 	 *
105 	 * Read the given gamma LUT register on the given CRTC, used to save the
106 	 * current LUT when force-restoring the fbdev for e.g. kdbg.
107 	 *
108 	 * This callback is optional.
109 	 *
110 	 * FIXME:
111 	 *
112 	 * This callback is functionally redundant with the core gamma table
113 	 * support and simply exists because the fbdev hasn't yet been
114 	 * refactored to use the core gamma table interfaces.
115 	 */
116 	void (*gamma_get)(struct drm_crtc *crtc, u16 *red, u16 *green,
117 			  u16 *blue, int regno);
118 
119 	/**
120 	 * @fb_probe:
121 	 *
122 	 * Driver callback to allocate and initialize the fbdev info structure.
123 	 * Furthermore it also needs to allocate the DRM framebuffer used to
124 	 * back the fbdev.
125 	 *
126 	 * This callback is mandatory.
127 	 *
128 	 * RETURNS:
129 	 *
130 	 * The driver should return 0 on success and a negative error code on
131 	 * failure.
132 	 */
133 	int (*fb_probe)(struct drm_fb_helper *helper,
134 			struct drm_fb_helper_surface_size *sizes);
135 
136 	/**
137 	 * @initial_config:
138 	 *
139 	 * Driver callback to setup an initial fbdev display configuration.
140 	 * Drivers can use this callback to tell the fbdev emulation what the
141 	 * preferred initial configuration is. This is useful to implement
142 	 * smooth booting where the fbdev (and subsequently all userspace) never
143 	 * changes the mode, but always inherits the existing configuration.
144 	 *
145 	 * This callback is optional.
146 	 *
147 	 * RETURNS:
148 	 *
149 	 * The driver should return true if a suitable initial configuration has
150 	 * been filled out and false when the fbdev helper should fall back to
151 	 * the default probing logic.
152 	 */
153 	bool (*initial_config)(struct drm_fb_helper *fb_helper,
154 			       struct drm_fb_helper_crtc **crtcs,
155 			       struct drm_display_mode **modes,
156 			       struct drm_fb_offset *offsets,
157 			       bool *enabled, int width, int height);
158 };
159 
160 struct drm_fb_helper_connector {
161 	struct drm_connector *connector;
162 };
163 
164 /**
165  * struct drm_fb_helper - main structure to emulate fbdev on top of KMS
166  * @fb: Scanout framebuffer object
167  * @dev: DRM device
168  * @crtc_count: number of possible CRTCs
169  * @crtc_info: per-CRTC helper state (mode, x/y offset, etc)
170  * @connector_count: number of connected connectors
171  * @connector_info_alloc_count: size of connector_info
172  * @connector_info: array of per-connector information
173  * @funcs: driver callbacks for fb helper
174  * @fbdev: emulated fbdev device info struct
175  * @pseudo_palette: fake palette of 16 colors
176  * @dirty_clip: clip rectangle used with deferred_io to accumulate damage to
177  *              the screen buffer
178  * @dirty_lock: spinlock protecting @dirty_clip
179  * @dirty_work: worker used to flush the framebuffer
180  * @resume_work: worker used during resume if the console lock is already taken
181  *
182  * This is the main structure used by the fbdev helpers. Drivers supporting
183  * fbdev emulation should embedded this into their overall driver structure.
184  * Drivers must also fill out a &struct drm_fb_helper_funcs with a few
185  * operations.
186  */
187 struct drm_fb_helper {
188 	struct drm_framebuffer *fb;
189 	struct drm_device *dev;
190 	int crtc_count;
191 	struct drm_fb_helper_crtc *crtc_info;
192 	int connector_count;
193 	int connector_info_alloc_count;
194 	struct drm_fb_helper_connector **connector_info;
195 	const struct drm_fb_helper_funcs *funcs;
196 	struct fb_info *fbdev;
197 	u32 pseudo_palette[17];
198 	struct drm_clip_rect dirty_clip;
199 	struct lock dirty_lock;
200 	struct work_struct dirty_work;
201 	struct work_struct resume_work;
202 
203 	/**
204 	 * @kernel_fb_list:
205 	 *
206 	 * Entry on the global kernel_fb_helper_list, used for kgdb entry/exit.
207 	 */
208 	struct list_head kernel_fb_list;
209 
210 	/**
211 	 * @delayed_hotplug:
212 	 *
213 	 * A hotplug was received while fbdev wasn't in control of the DRM
214 	 * device, i.e. another KMS master was active. The output configuration
215 	 * needs to be reprobe when fbdev is in control again.
216 	 */
217 	bool delayed_hotplug;
218 };
219 
220 /**
221  * define DRM_FB_HELPER_DEFAULT_OPS - helper define for drm drivers
222  *
223  * Helper define to register default implementations of drm_fb_helper
224  * functions. To be used in struct fb_ops of drm drivers.
225  */
226 #define DRM_FB_HELPER_DEFAULT_OPS \
227 	.fb_check_var	= drm_fb_helper_check_var, \
228 	.fb_set_par	= drm_fb_helper_set_par, \
229 	.fb_setcmap	= drm_fb_helper_setcmap, \
230 	.fb_blank	= drm_fb_helper_blank, \
231 	.fb_pan_display	= drm_fb_helper_pan_display, \
232 	.fb_debug_enter = drm_fb_helper_debug_enter, \
233 	.fb_debug_leave = drm_fb_helper_debug_leave, \
234 	.fb_ioctl	= drm_fb_helper_ioctl
235 
236 #ifdef CONFIG_DRM_FBDEV_EMULATION
237 void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
238 			   const struct drm_fb_helper_funcs *funcs);
239 int drm_fb_helper_init(struct drm_device *dev,
240 		       struct drm_fb_helper *helper, int max_conn);
241 void drm_fb_helper_fini(struct drm_fb_helper *helper);
242 int drm_fb_helper_blank(int blank, struct fb_info *info);
243 int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
244 			      struct fb_info *info);
245 int drm_fb_helper_set_par(struct fb_info *info);
246 int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
247 			    struct fb_info *info);
248 
249 int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper);
250 
251 struct fb_info *drm_fb_helper_alloc_fbi(struct drm_fb_helper *fb_helper);
252 void drm_fb_helper_unregister_fbi(struct drm_fb_helper *fb_helper);
253 void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helper,
254 			    uint32_t fb_width, uint32_t fb_height);
255 void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
256 			    uint32_t depth);
257 
258 void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper);
259 
260 void drm_fb_helper_deferred_io(struct fb_info *info,
261 			       struct list_head *pagelist);
262 
263 ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
264 			       size_t count, loff_t *ppos);
265 ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
266 				size_t count, loff_t *ppos);
267 
268 void drm_fb_helper_sys_fillrect(struct fb_info *info,
269 				const struct fb_fillrect *rect);
270 void drm_fb_helper_sys_copyarea(struct fb_info *info,
271 				const struct fb_copyarea *area);
272 void drm_fb_helper_sys_imageblit(struct fb_info *info,
273 				 const struct fb_image *image);
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, int bpp_sel);
293 int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper);
294 int drm_fb_helper_debug_enter(struct fb_info *info);
295 int drm_fb_helper_debug_leave(struct fb_info *info);
296 struct drm_display_mode *
297 drm_has_preferred_mode(struct drm_fb_helper_connector *fb_connector,
298 			int width, int height);
299 struct drm_display_mode *
300 drm_pick_cmdline_mode(struct drm_fb_helper_connector *fb_helper_conn);
301 
302 int drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper, struct drm_connector *connector);
303 int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
304 				       struct drm_connector *connector);
305 #else
306 static inline void drm_fb_helper_prepare(struct drm_device *dev,
307 					struct drm_fb_helper *helper,
308 					const struct drm_fb_helper_funcs *funcs)
309 {
310 }
311 
312 static inline int drm_fb_helper_init(struct drm_device *dev,
313 		       struct drm_fb_helper *helper,
314 		       int max_conn)
315 {
316 	return 0;
317 }
318 
319 static inline void drm_fb_helper_fini(struct drm_fb_helper *helper)
320 {
321 }
322 
323 static inline int drm_fb_helper_blank(int blank, struct fb_info *info)
324 {
325 	return 0;
326 }
327 
328 static inline int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
329 					    struct fb_info *info)
330 {
331 	return 0;
332 }
333 
334 static inline int drm_fb_helper_set_par(struct fb_info *info)
335 {
336 	return 0;
337 }
338 
339 static inline int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
340 					  struct fb_info *info)
341 {
342 	return 0;
343 }
344 
345 static inline int
346 drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
347 {
348 	return 0;
349 }
350 
351 static inline struct fb_info *
352 drm_fb_helper_alloc_fbi(struct drm_fb_helper *fb_helper)
353 {
354 	return NULL;
355 }
356 
357 static inline void drm_fb_helper_unregister_fbi(struct drm_fb_helper *fb_helper)
358 {
359 }
360 
361 static inline void drm_fb_helper_fill_var(struct fb_info *info,
362 					  struct drm_fb_helper *fb_helper,
363 					  uint32_t fb_width, uint32_t fb_height)
364 {
365 }
366 
367 static inline void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
368 					  uint32_t depth)
369 {
370 }
371 
372 static inline int drm_fb_helper_setcmap(struct fb_cmap *cmap,
373 					struct fb_info *info)
374 {
375 	return 0;
376 }
377 
378 static inline int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
379 				      unsigned long arg)
380 {
381 	return 0;
382 }
383 
384 static inline void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper)
385 {
386 }
387 
388 static inline void drm_fb_helper_deferred_io(struct fb_info *info,
389 					     struct list_head *pagelist)
390 {
391 }
392 
393 static inline ssize_t drm_fb_helper_sys_read(struct fb_info *info,
394 					     char __user *buf, size_t count,
395 					     loff_t *ppos)
396 {
397 	return -ENODEV;
398 }
399 
400 static inline ssize_t drm_fb_helper_sys_write(struct fb_info *info,
401 					      const char __user *buf,
402 					      size_t count, loff_t *ppos)
403 {
404 	return -ENODEV;
405 }
406 
407 static inline void drm_fb_helper_sys_fillrect(struct fb_info *info,
408 					      const struct fb_fillrect *rect)
409 {
410 }
411 
412 static inline void drm_fb_helper_sys_copyarea(struct fb_info *info,
413 					      const struct fb_copyarea *area)
414 {
415 }
416 
417 static inline void drm_fb_helper_sys_imageblit(struct fb_info *info,
418 					       const struct fb_image *image)
419 {
420 }
421 
422 static inline void drm_fb_helper_cfb_fillrect(struct fb_info *info,
423 					      const struct fb_fillrect *rect)
424 {
425 }
426 
427 static inline void drm_fb_helper_cfb_copyarea(struct fb_info *info,
428 					      const struct fb_copyarea *area)
429 {
430 }
431 
432 static inline void drm_fb_helper_cfb_imageblit(struct fb_info *info,
433 					       const struct fb_image *image)
434 {
435 }
436 
437 static inline void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper,
438 					     bool suspend)
439 {
440 }
441 
442 static inline void
443 drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper, bool suspend)
444 {
445 }
446 
447 static inline int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
448 {
449 	return 0;
450 }
451 
452 static inline int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper,
453 					       int bpp_sel)
454 {
455 	return 0;
456 }
457 
458 static inline int
459 drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper)
460 {
461 	return 0;
462 }
463 
464 static inline int drm_fb_helper_debug_enter(struct fb_info *info)
465 {
466 	return 0;
467 }
468 
469 static inline int drm_fb_helper_debug_leave(struct fb_info *info)
470 {
471 	return 0;
472 }
473 
474 static inline struct drm_display_mode *
475 drm_has_preferred_mode(struct drm_fb_helper_connector *fb_connector,
476 		       int width, int height)
477 {
478 	return NULL;
479 }
480 
481 static inline struct drm_display_mode *
482 drm_pick_cmdline_mode(struct drm_fb_helper_connector *fb_helper_conn,
483 		      int width, int height)
484 {
485 	return NULL;
486 }
487 
488 static inline int
489 drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper,
490 				struct drm_connector *connector)
491 {
492 	return 0;
493 }
494 
495 static inline int
496 drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
497 				   struct drm_connector *connector)
498 {
499 	return 0;
500 }
501 
502 #endif
503 
504 static inline int
505 drm_fb_helper_remove_conflicting_framebuffers(struct apertures_struct *a,
506 					      const char *name, bool primary)
507 {
508 #if IS_ENABLED(CONFIG_FB)
509 	return remove_conflicting_framebuffers(a, name, primary);
510 #else
511 	return 0;
512 #endif
513 }
514 
515 #endif
516