xref: /openbmc/linux/include/drm/drm_fb_helper.h (revision 27e45f2e)
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 enum mode_set_atomic {
41 	LEAVE_ATOMIC_MODE_SET,
42 	ENTER_ATOMIC_MODE_SET,
43 };
44 
45 /**
46  * struct drm_fb_helper_surface_size - describes fbdev size and scanout surface size
47  * @fb_width: fbdev width
48  * @fb_height: fbdev height
49  * @surface_width: scanout buffer width
50  * @surface_height: scanout buffer height
51  * @surface_bpp: scanout buffer bpp
52  * @surface_depth: scanout buffer depth
53  *
54  * Note that the scanout surface width/height may be larger than the fbdev
55  * width/height.  In case of multiple displays, the scanout surface is sized
56  * according to the largest width/height (so it is large enough for all CRTCs
57  * to scanout).  But the fbdev width/height is sized to the minimum width/
58  * height of all the displays.  This ensures that fbcon fits on the smallest
59  * of the attached displays. fb_width/fb_height is used by
60  * drm_fb_helper_fill_info() to fill out the &fb_info.var structure.
61  */
62 struct drm_fb_helper_surface_size {
63 	u32 fb_width;
64 	u32 fb_height;
65 	u32 surface_width;
66 	u32 surface_height;
67 	u32 surface_bpp;
68 	u32 surface_depth;
69 };
70 
71 /**
72  * struct drm_fb_helper_funcs - driver callbacks for the fbdev emulation library
73  *
74  * Driver callbacks used by the fbdev emulation helper library.
75  */
76 struct drm_fb_helper_funcs {
77 	/**
78 	 * @fb_probe:
79 	 *
80 	 * Driver callback to allocate and initialize the fbdev info structure.
81 	 * Furthermore it also needs to allocate the DRM framebuffer used to
82 	 * back the fbdev.
83 	 *
84 	 * This callback is mandatory.
85 	 *
86 	 * RETURNS:
87 	 *
88 	 * The driver should return 0 on success and a negative error code on
89 	 * failure.
90 	 */
91 	int (*fb_probe)(struct drm_fb_helper *helper,
92 			struct drm_fb_helper_surface_size *sizes);
93 
94 	/**
95 	 * @fb_dirty:
96 	 *
97 	 * Driver callback to update the framebuffer memory. If set, fbdev
98 	 * emulation will invoke this callback in regular intervals after
99 	 * the framebuffer has been written.
100 	 *
101 	 * This callback is optional.
102 	 *
103 	 * Returns:
104 	 * 0 on success, or an error code otherwise.
105 	 */
106 	int (*fb_dirty)(struct drm_fb_helper *helper, struct drm_clip_rect *clip);
107 };
108 
109 /**
110  * struct drm_fb_helper - main structure to emulate fbdev on top of KMS
111  * @fb: Scanout framebuffer object
112  * @dev: DRM device
113  * @funcs: driver callbacks for fb helper
114  * @info: emulated fbdev device info struct
115  * @pseudo_palette: fake palette of 16 colors
116  * @damage_clip: clip rectangle used with deferred_io to accumulate damage to
117  *                the screen buffer
118  * @damage_lock: spinlock protecting @damage_clip
119  * @damage_work: worker used to flush the framebuffer
120  * @resume_work: worker used during resume if the console lock is already taken
121  *
122  * This is the main structure used by the fbdev helpers. Drivers supporting
123  * fbdev emulation should embedded this into their overall driver structure.
124  * Drivers must also fill out a &struct drm_fb_helper_funcs with a few
125  * operations.
126  */
127 struct drm_fb_helper {
128 	/**
129 	 * @client:
130 	 *
131 	 * DRM client used by the generic fbdev emulation.
132 	 */
133 	struct drm_client_dev client;
134 
135 	/**
136 	 * @buffer:
137 	 *
138 	 * Framebuffer used by the generic fbdev emulation.
139 	 */
140 	struct drm_client_buffer *buffer;
141 
142 	struct drm_framebuffer *fb;
143 	struct drm_device *dev;
144 	const struct drm_fb_helper_funcs *funcs;
145 	struct fb_info *info;
146 	u32 pseudo_palette[17];
147 	struct drm_clip_rect damage_clip;
148 	spinlock_t damage_lock;
149 	struct work_struct damage_work;
150 	struct work_struct resume_work;
151 
152 	/**
153 	 * @lock:
154 	 *
155 	 * Top-level FBDEV helper lock. This protects all internal data
156 	 * structures and lists, such as @connector_info and @crtc_info.
157 	 *
158 	 * FIXME: fbdev emulation locking is a mess and long term we want to
159 	 * protect all helper internal state with this lock as well as reduce
160 	 * core KMS locking as much as possible.
161 	 */
162 	struct mutex lock;
163 
164 	/**
165 	 * @kernel_fb_list:
166 	 *
167 	 * Entry on the global kernel_fb_helper_list, used for kgdb entry/exit.
168 	 */
169 	struct list_head kernel_fb_list;
170 
171 	/**
172 	 * @delayed_hotplug:
173 	 *
174 	 * A hotplug was received while fbdev wasn't in control of the DRM
175 	 * device, i.e. another KMS master was active. The output configuration
176 	 * needs to be reprobe when fbdev is in control again.
177 	 */
178 	bool delayed_hotplug;
179 
180 	/**
181 	 * @deferred_setup:
182 	 *
183 	 * If no outputs are connected (disconnected or unknown) the FB helper
184 	 * code will defer setup until at least one of the outputs shows up.
185 	 * This field keeps track of the status so that setup can be retried
186 	 * at every hotplug event until it succeeds eventually.
187 	 *
188 	 * Protected by @lock.
189 	 */
190 	bool deferred_setup;
191 
192 	/**
193 	 * @preferred_bpp:
194 	 *
195 	 * Temporary storage for the driver's preferred BPP setting passed to
196 	 * FB helper initialization. This needs to be tracked so that deferred
197 	 * FB helper setup can pass this on.
198 	 *
199 	 * See also: @deferred_setup
200 	 */
201 	int preferred_bpp;
202 
203 	/**
204 	 * @hint_leak_smem_start:
205 	 *
206 	 * Hint to the fbdev emulation to store the framebuffer's physical
207 	 * address in struct &fb_info.fix.smem_start. If the hint is unset,
208 	 * the smem_start field should always be cleared to zero.
209 	 */
210 	bool hint_leak_smem_start;
211 };
212 
213 static inline struct drm_fb_helper *
214 drm_fb_helper_from_client(struct drm_client_dev *client)
215 {
216 	return container_of(client, struct drm_fb_helper, client);
217 }
218 
219 /**
220  * define DRM_FB_HELPER_DEFAULT_OPS - helper define for drm drivers
221  *
222  * Helper define to register default implementations of drm_fb_helper
223  * functions. To be used in struct fb_ops of drm drivers.
224  */
225 #define DRM_FB_HELPER_DEFAULT_OPS \
226 	.fb_check_var	= drm_fb_helper_check_var, \
227 	.fb_set_par	= drm_fb_helper_set_par, \
228 	.fb_setcmap	= drm_fb_helper_setcmap, \
229 	.fb_blank	= drm_fb_helper_blank, \
230 	.fb_pan_display	= drm_fb_helper_pan_display, \
231 	.fb_debug_enter = drm_fb_helper_debug_enter, \
232 	.fb_debug_leave = drm_fb_helper_debug_leave, \
233 	.fb_ioctl	= drm_fb_helper_ioctl
234 
235 #ifdef CONFIG_DRM_FBDEV_EMULATION
236 void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
237 			   const struct drm_fb_helper_funcs *funcs);
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_unregister_info(struct drm_fb_helper *fb_helper);
251 void drm_fb_helper_fill_info(struct fb_info *info,
252 			     struct drm_fb_helper *fb_helper,
253 			     struct drm_fb_helper_surface_size *sizes);
254 
255 void drm_fb_helper_deferred_io(struct fb_info *info, struct list_head *pagereflist);
256 
257 ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
258 			       size_t count, loff_t *ppos);
259 ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
260 				size_t count, loff_t *ppos);
261 
262 void drm_fb_helper_sys_fillrect(struct fb_info *info,
263 				const struct fb_fillrect *rect);
264 void drm_fb_helper_sys_copyarea(struct fb_info *info,
265 				const struct fb_copyarea *area);
266 void drm_fb_helper_sys_imageblit(struct fb_info *info,
267 				 const struct fb_image *image);
268 
269 ssize_t drm_fb_helper_cfb_read(struct fb_info *info, char __user *buf,
270 			       size_t count, loff_t *ppos);
271 ssize_t drm_fb_helper_cfb_write(struct fb_info *info, const char __user *buf,
272 				size_t count, loff_t *ppos);
273 
274 void drm_fb_helper_cfb_fillrect(struct fb_info *info,
275 				const struct fb_fillrect *rect);
276 void drm_fb_helper_cfb_copyarea(struct fb_info *info,
277 				const struct fb_copyarea *area);
278 void drm_fb_helper_cfb_imageblit(struct fb_info *info,
279 				 const struct fb_image *image);
280 
281 void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend);
282 void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
283 					bool suspend);
284 
285 int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info);
286 
287 int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
288 			unsigned long arg);
289 
290 int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper);
291 int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel);
292 int drm_fb_helper_debug_enter(struct fb_info *info);
293 int drm_fb_helper_debug_leave(struct fb_info *info);
294 
295 void drm_fb_helper_lastclose(struct drm_device *dev);
296 void drm_fb_helper_output_poll_changed(struct drm_device *dev);
297 #else
298 static inline void drm_fb_helper_prepare(struct drm_device *dev,
299 					struct drm_fb_helper *helper,
300 					const struct drm_fb_helper_funcs *funcs)
301 {
302 }
303 
304 static inline int drm_fb_helper_init(struct drm_device *dev,
305 		       struct drm_fb_helper *helper)
306 {
307 	/* So drivers can use it to free the struct */
308 	helper->dev = dev;
309 	dev->fb_helper = helper;
310 
311 	return 0;
312 }
313 
314 static inline void drm_fb_helper_fini(struct drm_fb_helper *helper)
315 {
316 	if (helper && helper->dev)
317 		helper->dev->fb_helper = NULL;
318 }
319 
320 static inline int drm_fb_helper_blank(int blank, struct fb_info *info)
321 {
322 	return 0;
323 }
324 
325 static inline int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
326 					    struct fb_info *info)
327 {
328 	return 0;
329 }
330 
331 static inline int drm_fb_helper_set_par(struct fb_info *info)
332 {
333 	return 0;
334 }
335 
336 static inline int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
337 					  struct fb_info *info)
338 {
339 	return 0;
340 }
341 
342 static inline int
343 drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
344 {
345 	return 0;
346 }
347 
348 static inline struct fb_info *
349 drm_fb_helper_alloc_info(struct drm_fb_helper *fb_helper)
350 {
351 	return NULL;
352 }
353 
354 static inline void drm_fb_helper_unregister_info(struct drm_fb_helper *fb_helper)
355 {
356 }
357 
358 static inline void
359 drm_fb_helper_fill_info(struct fb_info *info,
360 			struct drm_fb_helper *fb_helper,
361 			struct drm_fb_helper_surface_size *sizes)
362 {
363 }
364 
365 static inline int drm_fb_helper_setcmap(struct fb_cmap *cmap,
366 					struct fb_info *info)
367 {
368 	return 0;
369 }
370 
371 static inline int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
372 				      unsigned long arg)
373 {
374 	return 0;
375 }
376 
377 static inline void drm_fb_helper_deferred_io(struct fb_info *info,
378 					     struct list_head *pagelist)
379 {
380 }
381 
382 static inline int drm_fb_helper_defio_init(struct drm_fb_helper *fb_helper)
383 {
384 	return -ENODEV;
385 }
386 
387 static inline ssize_t drm_fb_helper_sys_read(struct fb_info *info,
388 					     char __user *buf, size_t count,
389 					     loff_t *ppos)
390 {
391 	return -ENODEV;
392 }
393 
394 static inline ssize_t drm_fb_helper_sys_write(struct fb_info *info,
395 					      const char __user *buf,
396 					      size_t count, loff_t *ppos)
397 {
398 	return -ENODEV;
399 }
400 
401 static inline void drm_fb_helper_sys_fillrect(struct fb_info *info,
402 					      const struct fb_fillrect *rect)
403 {
404 }
405 
406 static inline void drm_fb_helper_sys_copyarea(struct fb_info *info,
407 					      const struct fb_copyarea *area)
408 {
409 }
410 
411 static inline void drm_fb_helper_sys_imageblit(struct fb_info *info,
412 					       const struct fb_image *image)
413 {
414 }
415 
416 static inline ssize_t drm_fb_helper_cfb_read(struct fb_info *info, char __user *buf,
417 					     size_t count, loff_t *ppos)
418 {
419 	return -ENODEV;
420 }
421 
422 static inline ssize_t drm_fb_helper_cfb_write(struct fb_info *info, const char __user *buf,
423 					      size_t count, loff_t *ppos)
424 {
425 	return -ENODEV;
426 }
427 
428 static inline void drm_fb_helper_cfb_fillrect(struct fb_info *info,
429 					      const struct fb_fillrect *rect)
430 {
431 }
432 
433 static inline void drm_fb_helper_cfb_copyarea(struct fb_info *info,
434 					      const struct fb_copyarea *area)
435 {
436 }
437 
438 static inline void drm_fb_helper_cfb_imageblit(struct fb_info *info,
439 					       const struct fb_image *image)
440 {
441 }
442 
443 static inline void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper,
444 					     bool suspend)
445 {
446 }
447 
448 static inline void
449 drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper, bool suspend)
450 {
451 }
452 
453 static inline int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
454 {
455 	return 0;
456 }
457 
458 static inline int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper,
459 					       int bpp_sel)
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 void drm_fb_helper_lastclose(struct drm_device *dev)
475 {
476 }
477 
478 static inline void drm_fb_helper_output_poll_changed(struct drm_device *dev)
479 {
480 }
481 #endif
482 
483 #endif
484