xref: /linux/include/drm/drm_fb_helper.h (revision 6ea3aacc8e89298702812a1556eb1e378a80e02b)
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_dirty:
74 	 *
75 	 * Driver callback to update the framebuffer memory. If set, fbdev
76 	 * emulation will invoke this callback in regular intervals after
77 	 * the framebuffer has been written.
78 	 *
79 	 * This callback is optional.
80 	 *
81 	 * Returns:
82 	 * 0 on success, or an error code otherwise.
83 	 */
84 	int (*fb_dirty)(struct drm_fb_helper *helper, struct drm_clip_rect *clip);
85 
86 	/**
87 	 * @fb_restore:
88 	 *
89 	 * Driver callback to restore internal fbdev state. If set, fbdev
90 	 * emulation will invoke this callback after restoring the display
91 	 * mode.
92 	 *
93 	 * Only for i915. Do not use in new code.
94 	 *
95 	 * TODO: Fix i915 to not require this callback.
96 	 */
97 	void (*fb_restore)(struct drm_fb_helper *helper);
98 
99 	/**
100 	 * @fb_set_suspend:
101 	 *
102 	 * Driver callback to suspend or resume, if set, fbdev emulation will
103 	 * invoke this callback during suspend and resume. Driver should call
104 	 * fb_set_suspend() from their implementation. If not set, fbdev
105 	 * emulation will invoke fb_set_suspend() directly.
106 	 *
107 	 * Only for i915. Do not use in new code.
108 	 *
109 	 * TODO: Fix i915 to not require this callback.
110 	 */
111 	void (*fb_set_suspend)(struct drm_fb_helper *helper, bool suspend);
112 };
113 
114 /**
115  * struct drm_fb_helper - main structure to emulate fbdev on top of KMS
116  * @fb: Scanout framebuffer object
117  * @dev: DRM device
118  * @funcs: driver callbacks for fb helper
119  * @info: emulated fbdev device info struct
120  * @pseudo_palette: fake palette of 16 colors
121  * @damage_clip: clip rectangle used with deferred_io to accumulate damage to
122  *                the screen buffer
123  * @damage_lock: spinlock protecting @damage_clip
124  * @damage_work: worker used to flush the framebuffer
125  * @resume_work: worker used during resume if the console lock is already taken
126  *
127  * This is the main structure used by the fbdev helpers. Drivers supporting
128  * fbdev emulation should embedded this into their overall driver structure.
129  * Drivers must also fill out a &struct drm_fb_helper_funcs with a few
130  * operations.
131  */
132 struct drm_fb_helper {
133 	/**
134 	 * @client:
135 	 *
136 	 * DRM client used by the generic fbdev emulation.
137 	 */
138 	struct drm_client_dev client;
139 
140 	/**
141 	 * @buffer:
142 	 *
143 	 * Framebuffer used by the generic fbdev emulation.
144 	 */
145 	struct drm_client_buffer *buffer;
146 
147 	struct drm_framebuffer *fb;
148 	struct drm_device *dev;
149 	const struct drm_fb_helper_funcs *funcs;
150 	struct fb_info *info;
151 	u32 pseudo_palette[17];
152 	struct drm_clip_rect damage_clip;
153 	spinlock_t damage_lock;
154 	struct work_struct damage_work;
155 	struct work_struct resume_work;
156 
157 	/**
158 	 * @lock:
159 	 *
160 	 * Top-level FBDEV helper lock. This protects all internal data
161 	 * structures and lists, such as @connector_info and @crtc_info.
162 	 *
163 	 * FIXME: fbdev emulation locking is a mess and long term we want to
164 	 * protect all helper internal state with this lock as well as reduce
165 	 * core KMS locking as much as possible.
166 	 */
167 	struct mutex lock;
168 
169 	/**
170 	 * @delayed_hotplug:
171 	 *
172 	 * A hotplug was received while fbdev wasn't in control of the DRM
173 	 * device, i.e. another KMS master was active. The output configuration
174 	 * needs to be reprobe when fbdev is in control again.
175 	 */
176 	bool delayed_hotplug;
177 
178 	/**
179 	 * @deferred_setup:
180 	 *
181 	 * If no outputs are connected (disconnected or unknown) the FB helper
182 	 * code will defer setup until at least one of the outputs shows up.
183 	 * This field keeps track of the status so that setup can be retried
184 	 * at every hotplug event until it succeeds eventually.
185 	 *
186 	 * Protected by @lock.
187 	 */
188 	bool deferred_setup;
189 
190 	/**
191 	 * @preferred_bpp:
192 	 *
193 	 * Temporary storage for the driver's preferred BPP setting passed to
194 	 * FB helper initialization. This needs to be tracked so that deferred
195 	 * FB helper setup can pass this on.
196 	 *
197 	 * See also: @deferred_setup
198 	 */
199 	int preferred_bpp;
200 
201 #ifdef CONFIG_FB_DEFERRED_IO
202 	/**
203 	 * @fbdefio:
204 	 *
205 	 * Temporary storage for the driver's FB deferred I/O handler. If the
206 	 * driver uses the DRM fbdev emulation layer, this is set by the core
207 	 * to a generic deferred I/O handler if a driver is preferring to use
208 	 * a shadow buffer.
209 	 */
210 	struct fb_deferred_io fbdefio;
211 #endif
212 };
213 
214 static inline struct drm_fb_helper *
215 drm_fb_helper_from_client(struct drm_client_dev *client)
216 {
217 	return container_of(client, struct drm_fb_helper, client);
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_ioctl	= drm_fb_helper_ioctl
233 
234 #ifdef CONFIG_DRM_FBDEV_EMULATION
235 void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
236 			   unsigned int preferred_bpp,
237 			   const struct drm_fb_helper_funcs *funcs);
238 void drm_fb_helper_unprepare(struct drm_fb_helper *fb_helper);
239 int drm_fb_helper_init(struct drm_device *dev, struct drm_fb_helper *helper);
240 void drm_fb_helper_fini(struct drm_fb_helper *helper);
241 int drm_fb_helper_blank(int blank, struct fb_info *info);
242 int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
243 			      struct fb_info *info);
244 int drm_fb_helper_set_par(struct fb_info *info);
245 int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
246 			    struct fb_info *info);
247 
248 int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper,
249 					      bool force);
250 
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 #ifdef CONFIG_FB_DEFERRED_IO
260 void drm_fb_helper_deferred_io(struct fb_info *info, struct list_head *pagereflist);
261 #endif
262 
263 void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend);
264 void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
265 					bool suspend);
266 
267 int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info);
268 
269 int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
270 			unsigned long arg);
271 
272 int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper);
273 int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper);
274 #else
275 static inline void drm_fb_helper_prepare(struct drm_device *dev,
276 					 struct drm_fb_helper *helper,
277 					 unsigned int preferred_bpp,
278 					 const struct drm_fb_helper_funcs *funcs)
279 {
280 }
281 
282 static inline void drm_fb_helper_unprepare(struct drm_fb_helper *fb_helper)
283 {
284 }
285 
286 static inline int drm_fb_helper_init(struct drm_device *dev,
287 		       struct drm_fb_helper *helper)
288 {
289 	/* So drivers can use it to free the struct */
290 	helper->dev = dev;
291 	dev->fb_helper = helper;
292 
293 	return 0;
294 }
295 
296 static inline void drm_fb_helper_fini(struct drm_fb_helper *helper)
297 {
298 	if (helper && helper->dev)
299 		helper->dev->fb_helper = NULL;
300 }
301 
302 static inline int drm_fb_helper_blank(int blank, struct fb_info *info)
303 {
304 	return 0;
305 }
306 
307 static inline int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
308 					    struct fb_info *info)
309 {
310 	return 0;
311 }
312 
313 static inline int drm_fb_helper_set_par(struct fb_info *info)
314 {
315 	return 0;
316 }
317 
318 static inline int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
319 					  struct fb_info *info)
320 {
321 	return 0;
322 }
323 
324 static inline int
325 drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
326 {
327 	return 0;
328 }
329 
330 static inline void drm_fb_helper_unregister_info(struct drm_fb_helper *fb_helper)
331 {
332 }
333 
334 static inline void
335 drm_fb_helper_fill_info(struct fb_info *info,
336 			struct drm_fb_helper *fb_helper,
337 			struct drm_fb_helper_surface_size *sizes)
338 {
339 }
340 
341 static inline int drm_fb_helper_setcmap(struct fb_cmap *cmap,
342 					struct fb_info *info)
343 {
344 	return 0;
345 }
346 
347 static inline int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
348 				      unsigned long arg)
349 {
350 	return 0;
351 }
352 
353 #ifdef CONFIG_FB_DEFERRED_IO
354 static inline void drm_fb_helper_deferred_io(struct fb_info *info,
355 					     struct list_head *pagelist)
356 {
357 }
358 #endif
359 
360 static inline void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper,
361 					     bool suspend)
362 {
363 }
364 
365 static inline void
366 drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper, bool suspend)
367 {
368 }
369 
370 static inline int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
371 {
372 	return 0;
373 }
374 
375 static inline int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper)
376 {
377 	return 0;
378 }
379 #endif
380 
381 #endif
382