xref: /linux/include/drm/drm_fb_helper.h (revision d53b8e36925256097a08d7cb749198d85cbf9b2b)
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_damage_range(struct fb_info *info, off_t off, size_t len);
257 void drm_fb_helper_damage_area(struct fb_info *info, u32 x, u32 y, u32 width, u32 height);
258 
259 void drm_fb_helper_deferred_io(struct fb_info *info, struct list_head *pagereflist);
260 
261 void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend);
262 void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
263 					bool suspend);
264 
265 int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info);
266 
267 int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
268 			unsigned long arg);
269 
270 int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper);
271 int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper);
272 int drm_fb_helper_debug_enter(struct fb_info *info);
273 int drm_fb_helper_debug_leave(struct fb_info *info);
274 void drm_fb_helper_lastclose(struct drm_device *dev);
275 #else
276 static inline void drm_fb_helper_prepare(struct drm_device *dev,
277 					 struct drm_fb_helper *helper,
278 					 unsigned int preferred_bpp,
279 					 const struct drm_fb_helper_funcs *funcs)
280 {
281 }
282 
283 static inline void drm_fb_helper_unprepare(struct drm_fb_helper *fb_helper)
284 {
285 }
286 
287 static inline int drm_fb_helper_init(struct drm_device *dev,
288 		       struct drm_fb_helper *helper)
289 {
290 	/* So drivers can use it to free the struct */
291 	helper->dev = dev;
292 	dev->fb_helper = helper;
293 
294 	return 0;
295 }
296 
297 static inline void drm_fb_helper_fini(struct drm_fb_helper *helper)
298 {
299 	if (helper && helper->dev)
300 		helper->dev->fb_helper = NULL;
301 }
302 
303 static inline int drm_fb_helper_blank(int blank, struct fb_info *info)
304 {
305 	return 0;
306 }
307 
308 static inline int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
309 					    struct fb_info *info)
310 {
311 	return 0;
312 }
313 
314 static inline int drm_fb_helper_set_par(struct fb_info *info)
315 {
316 	return 0;
317 }
318 
319 static inline int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
320 					  struct fb_info *info)
321 {
322 	return 0;
323 }
324 
325 static inline int
326 drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
327 {
328 	return 0;
329 }
330 
331 static inline struct fb_info *
332 drm_fb_helper_alloc_info(struct drm_fb_helper *fb_helper)
333 {
334 	return NULL;
335 }
336 
337 static inline void drm_fb_helper_release_info(struct drm_fb_helper *fb_helper)
338 {
339 }
340 
341 static inline void drm_fb_helper_unregister_info(struct drm_fb_helper *fb_helper)
342 {
343 }
344 
345 static inline void
346 drm_fb_helper_fill_info(struct fb_info *info,
347 			struct drm_fb_helper *fb_helper,
348 			struct drm_fb_helper_surface_size *sizes)
349 {
350 }
351 
352 static inline int drm_fb_helper_setcmap(struct fb_cmap *cmap,
353 					struct fb_info *info)
354 {
355 	return 0;
356 }
357 
358 static inline int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
359 				      unsigned long arg)
360 {
361 	return 0;
362 }
363 
364 static inline void drm_fb_helper_deferred_io(struct fb_info *info,
365 					     struct list_head *pagelist)
366 {
367 }
368 
369 static inline void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper,
370 					     bool suspend)
371 {
372 }
373 
374 static inline void
375 drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper, bool suspend)
376 {
377 }
378 
379 static inline int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
380 {
381 	return 0;
382 }
383 
384 static inline int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper)
385 {
386 	return 0;
387 }
388 
389 static inline int drm_fb_helper_debug_enter(struct fb_info *info)
390 {
391 	return 0;
392 }
393 
394 static inline int drm_fb_helper_debug_leave(struct fb_info *info)
395 {
396 	return 0;
397 }
398 
399 static inline void drm_fb_helper_lastclose(struct drm_device *dev)
400 {
401 }
402 #endif
403 
404 #endif
405