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 
36 enum mode_set_atomic {
37 	LEAVE_ATOMIC_MODE_SET,
38 	ENTER_ATOMIC_MODE_SET,
39 };
40 
41 struct drm_fb_offset {
42 	int x, y;
43 };
44 
45 struct drm_fb_helper_crtc {
46 	struct drm_mode_set mode_set;
47 	struct drm_display_mode *desired_mode;
48 	int x, y;
49 };
50 
51 /**
52  * struct drm_fb_helper_surface_size - describes fbdev size and scanout surface size
53  * @fb_width: fbdev width
54  * @fb_height: fbdev height
55  * @surface_width: scanout buffer width
56  * @surface_height: scanout buffer height
57  * @surface_bpp: scanout buffer bpp
58  * @surface_depth: scanout buffer depth
59  *
60  * Note that the scanout surface width/height may be larger than the fbdev
61  * width/height.  In case of multiple displays, the scanout surface is sized
62  * according to the largest width/height (so it is large enough for all CRTCs
63  * to scanout).  But the fbdev width/height is sized to the minimum width/
64  * height of all the displays.  This ensures that fbcon fits on the smallest
65  * of the attached displays.
66  *
67  * So what is passed to drm_fb_helper_fill_var() should be fb_width/fb_height,
68  * rather than the surface size.
69  */
70 struct drm_fb_helper_surface_size {
71 	u32 fb_width;
72 	u32 fb_height;
73 	u32 surface_width;
74 	u32 surface_height;
75 	u32 surface_bpp;
76 	u32 surface_depth;
77 };
78 
79 /**
80  * struct drm_fb_helper_funcs - driver callbacks for the fbdev emulation library
81  *
82  * Driver callbacks used by the fbdev emulation helper library.
83  */
84 struct drm_fb_helper_funcs {
85 	/**
86 	 * @gamma_set:
87 	 *
88 	 * Set the given gamma LUT register on the given CRTC.
89 	 *
90 	 * This callback is optional.
91 	 *
92 	 * FIXME:
93 	 *
94 	 * This callback is functionally redundant with the core gamma table
95 	 * support and simply exists because the fbdev hasn't yet been
96 	 * refactored to use the core gamma table interfaces.
97 	 */
98 	void (*gamma_set)(struct drm_crtc *crtc, u16 red, u16 green,
99 			  u16 blue, int regno);
100 	/**
101 	 * @gamma_get:
102 	 *
103 	 * Read the given gamma LUT register on the given CRTC, used to save the
104 	 * current LUT when force-restoring the fbdev for e.g. kdbg.
105 	 *
106 	 * This callback is optional.
107 	 *
108 	 * FIXME:
109 	 *
110 	 * This callback is functionally redundant with the core gamma table
111 	 * support and simply exists because the fbdev hasn't yet been
112 	 * refactored to use the core gamma table interfaces.
113 	 */
114 	void (*gamma_get)(struct drm_crtc *crtc, u16 *red, u16 *green,
115 			  u16 *blue, int regno);
116 
117 	/**
118 	 * @fb_probe:
119 	 *
120 	 * Driver callback to allocate and initialize the fbdev info structure.
121 	 * Furthermore it also needs to allocate the DRM framebuffer used to
122 	 * back the fbdev.
123 	 *
124 	 * This callback is mandatory.
125 	 *
126 	 * RETURNS:
127 	 *
128 	 * The driver should return 0 on success and a negative error code on
129 	 * failure.
130 	 */
131 	int (*fb_probe)(struct drm_fb_helper *helper,
132 			struct drm_fb_helper_surface_size *sizes);
133 
134 	/**
135 	 * @initial_config:
136 	 *
137 	 * Driver callback to setup an initial fbdev display configuration.
138 	 * Drivers can use this callback to tell the fbdev emulation what the
139 	 * preferred initial configuration is. This is useful to implement
140 	 * smooth booting where the fbdev (and subsequently all userspace) never
141 	 * changes the mode, but always inherits the existing configuration.
142 	 *
143 	 * This callback is optional.
144 	 *
145 	 * RETURNS:
146 	 *
147 	 * The driver should return true if a suitable initial configuration has
148 	 * been filled out and false when the fbdev helper should fall back to
149 	 * the default probing logic.
150 	 */
151 	bool (*initial_config)(struct drm_fb_helper *fb_helper,
152 			       struct drm_fb_helper_crtc **crtcs,
153 			       struct drm_display_mode **modes,
154 			       struct drm_fb_offset *offsets,
155 			       bool *enabled, int width, int height);
156 };
157 
158 struct drm_fb_helper_connector {
159 	struct drm_connector *connector;
160 };
161 
162 /**
163  * struct drm_fb_helper - main structure to emulate fbdev on top of KMS
164  * @fb: Scanout framebuffer object
165  * @dev: DRM device
166  * @crtc_count: number of possible CRTCs
167  * @crtc_info: per-CRTC helper state (mode, x/y offset, etc)
168  * @connector_count: number of connected connectors
169  * @connector_info_alloc_count: size of connector_info
170  * @connector_info: array of per-connector information
171  * @funcs: driver callbacks for fb helper
172  * @fbdev: emulated fbdev device info struct
173  * @pseudo_palette: fake palette of 16 colors
174  *
175  * This is the main structure used by the fbdev helpers. Drivers supporting
176  * fbdev emulation should embedded this into their overall driver structure.
177  * Drivers must also fill out a struct &drm_fb_helper_funcs with a few
178  * operations.
179  */
180 struct drm_fb_helper {
181 	struct drm_framebuffer *fb;
182 	struct drm_device *dev;
183 	int crtc_count;
184 	struct drm_fb_helper_crtc *crtc_info;
185 	int connector_count;
186 	int connector_info_alloc_count;
187 	struct drm_fb_helper_connector **connector_info;
188 	const struct drm_fb_helper_funcs *funcs;
189 	struct fb_info *fbdev;
190 	u32 pseudo_palette[17];
191 
192 	/**
193 	 * @kernel_fb_list:
194 	 *
195 	 * Entry on the global kernel_fb_helper_list, used for kgdb entry/exit.
196 	 */
197 	struct list_head kernel_fb_list;
198 
199 	/**
200 	 * @delayed_hotplug:
201 	 *
202 	 * A hotplug was received while fbdev wasn't in control of the DRM
203 	 * device, i.e. another KMS master was active. The output configuration
204 	 * needs to be reprobe when fbdev is in control again.
205 	 */
206 	bool delayed_hotplug;
207 
208 	/**
209 	 * @atomic:
210 	 *
211 	 * Use atomic updates for restore_fbdev_mode(), etc.  This defaults to
212 	 * true if driver has DRIVER_ATOMIC feature flag, but drivers can
213 	 * override it to true after drm_fb_helper_init() if they support atomic
214 	 * modeset but do not yet advertise DRIVER_ATOMIC (note that fb-helper
215 	 * does not require ASYNC commits).
216 	 */
217 	bool atomic;
218 };
219 
220 #define CONFIG_DRM_FBDEV_EMULATION 1
221 #ifdef CONFIG_DRM_FBDEV_EMULATION
222 int drm_fb_helper_modinit(void);
223 void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
224 			   const struct drm_fb_helper_funcs *funcs);
225 int drm_fb_helper_init(struct drm_device *dev,
226 		       struct drm_fb_helper *helper, int crtc_count,
227 		       int max_conn);
228 void drm_fb_helper_fini(struct drm_fb_helper *helper);
229 int drm_fb_helper_blank(int blank, struct fb_info *info);
230 int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
231 			      struct fb_info *info);
232 int drm_fb_helper_set_par(struct fb_info *info);
233 int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
234 			    struct fb_info *info);
235 
236 int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper);
237 
238 struct fb_info *drm_fb_helper_alloc_fbi(struct drm_fb_helper *fb_helper);
239 void drm_fb_helper_unregister_fbi(struct drm_fb_helper *fb_helper);
240 void drm_fb_helper_release_fbi(struct drm_fb_helper *fb_helper);
241 void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helper,
242 			    uint32_t fb_width, uint32_t fb_height);
243 void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
244 			    uint32_t depth);
245 
246 void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper);
247 
248 ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
249 			       size_t count, loff_t *ppos);
250 ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
251 				size_t count, loff_t *ppos);
252 
253 void drm_fb_helper_sys_fillrect(struct fb_info *info,
254 				const struct fb_fillrect *rect);
255 void drm_fb_helper_sys_copyarea(struct fb_info *info,
256 				const struct fb_copyarea *area);
257 void drm_fb_helper_sys_imageblit(struct fb_info *info,
258 				 const struct fb_image *image);
259 
260 void drm_fb_helper_cfb_fillrect(struct fb_info *info,
261 				const struct fb_fillrect *rect);
262 void drm_fb_helper_cfb_copyarea(struct fb_info *info,
263 				const struct fb_copyarea *area);
264 void drm_fb_helper_cfb_imageblit(struct fb_info *info,
265 				 const struct fb_image *image);
266 
267 void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, int state);
268 
269 int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info);
270 
271 int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper);
272 int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel);
273 int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper);
274 int drm_fb_helper_debug_enter(struct fb_info *info);
275 int drm_fb_helper_debug_leave(struct fb_info *info);
276 struct drm_display_mode *
277 drm_has_preferred_mode(struct drm_fb_helper_connector *fb_connector,
278 			int width, int height);
279 struct drm_display_mode *
280 drm_pick_cmdline_mode(struct drm_fb_helper_connector *fb_helper_conn,
281 		      int width, int height);
282 
283 int drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper, struct drm_connector *connector);
284 int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
285 				       struct drm_connector *connector);
286 #else
287 static inline int drm_fb_helper_modinit(void)
288 {
289 	return 0;
290 }
291 
292 static inline void drm_fb_helper_prepare(struct drm_device *dev,
293 					struct drm_fb_helper *helper,
294 					const struct drm_fb_helper_funcs *funcs)
295 {
296 }
297 
298 static inline int drm_fb_helper_init(struct drm_device *dev,
299 		       struct drm_fb_helper *helper, int crtc_count,
300 		       int max_conn)
301 {
302 	return 0;
303 }
304 
305 static inline void drm_fb_helper_fini(struct drm_fb_helper *helper)
306 {
307 }
308 
309 static inline int drm_fb_helper_blank(int blank, struct fb_info *info)
310 {
311 	return 0;
312 }
313 
314 static inline int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
315 					    struct fb_info *info)
316 {
317 	return 0;
318 }
319 
320 static inline int drm_fb_helper_set_par(struct fb_info *info)
321 {
322 	return 0;
323 }
324 
325 static inline int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
326 					  struct fb_info *info)
327 {
328 	return 0;
329 }
330 
331 static inline int
332 drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
333 {
334 	return 0;
335 }
336 
337 static inline struct fb_info *
338 drm_fb_helper_alloc_fbi(struct drm_fb_helper *fb_helper)
339 {
340 	return NULL;
341 }
342 
343 static inline void drm_fb_helper_unregister_fbi(struct drm_fb_helper *fb_helper)
344 {
345 }
346 static inline void drm_fb_helper_release_fbi(struct drm_fb_helper *fb_helper)
347 {
348 }
349 
350 static inline void drm_fb_helper_fill_var(struct fb_info *info,
351 					  struct drm_fb_helper *fb_helper,
352 					  uint32_t fb_width, uint32_t fb_height)
353 {
354 }
355 
356 static inline void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
357 					  uint32_t depth)
358 {
359 }
360 
361 static inline int drm_fb_helper_setcmap(struct fb_cmap *cmap,
362 					struct fb_info *info)
363 {
364 	return 0;
365 }
366 
367 static inline void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper)
368 {
369 }
370 
371 static inline ssize_t drm_fb_helper_sys_read(struct fb_info *info,
372 					     char __user *buf, size_t count,
373 					     loff_t *ppos)
374 {
375 	return -ENODEV;
376 }
377 
378 static inline ssize_t drm_fb_helper_sys_write(struct fb_info *info,
379 					      const char __user *buf,
380 					      size_t count, loff_t *ppos)
381 {
382 	return -ENODEV;
383 }
384 
385 static inline void drm_fb_helper_sys_fillrect(struct fb_info *info,
386 					      const struct fb_fillrect *rect)
387 {
388 }
389 
390 static inline void drm_fb_helper_sys_copyarea(struct fb_info *info,
391 					      const struct fb_copyarea *area)
392 {
393 }
394 
395 static inline void drm_fb_helper_sys_imageblit(struct fb_info *info,
396 					       const struct fb_image *image)
397 {
398 }
399 
400 static inline void drm_fb_helper_cfb_fillrect(struct fb_info *info,
401 					      const struct fb_fillrect *rect)
402 {
403 }
404 
405 static inline void drm_fb_helper_cfb_copyarea(struct fb_info *info,
406 					      const struct fb_copyarea *area)
407 {
408 }
409 
410 static inline void drm_fb_helper_cfb_imageblit(struct fb_info *info,
411 					       const struct fb_image *image)
412 {
413 }
414 
415 static inline void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper,
416 					     int state)
417 {
418 }
419 
420 static inline int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
421 {
422 	return 0;
423 }
424 
425 static inline int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper,
426 					       int bpp_sel)
427 {
428 	return 0;
429 }
430 
431 static inline int
432 drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper)
433 {
434 	return 0;
435 }
436 
437 static inline int drm_fb_helper_debug_enter(struct fb_info *info)
438 {
439 	return 0;
440 }
441 
442 static inline int drm_fb_helper_debug_leave(struct fb_info *info)
443 {
444 	return 0;
445 }
446 
447 static inline struct drm_display_mode *
448 drm_has_preferred_mode(struct drm_fb_helper_connector *fb_connector,
449 		       int width, int height)
450 {
451 	return NULL;
452 }
453 
454 static inline struct drm_display_mode *
455 drm_pick_cmdline_mode(struct drm_fb_helper_connector *fb_helper_conn,
456 		      int width, int height)
457 {
458 	return NULL;
459 }
460 
461 static inline int
462 drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper,
463 				struct drm_connector *connector)
464 {
465 	return 0;
466 }
467 
468 static inline int
469 drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
470 				   struct drm_connector *connector)
471 {
472 	return 0;
473 }
474 #endif
475 #endif
476