xref: /openbmc/linux/include/drm/drm_fb_helper.h (revision c6fddb28)
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_client.h>
36 #include <drm/drm_crtc.h>
37 #include <drm/drm_device.h>
38 #include <linux/kgdb.h>
39 #include <linux/vgaarb.h>
40 
41 enum mode_set_atomic {
42 	LEAVE_ATOMIC_MODE_SET,
43 	ENTER_ATOMIC_MODE_SET,
44 };
45 
46 /**
47  * struct drm_fb_helper_surface_size - describes fbdev size and scanout surface size
48  * @fb_width: fbdev width
49  * @fb_height: fbdev height
50  * @surface_width: scanout buffer width
51  * @surface_height: scanout buffer height
52  * @surface_bpp: scanout buffer bpp
53  * @surface_depth: scanout buffer depth
54  *
55  * Note that the scanout surface width/height may be larger than the fbdev
56  * width/height.  In case of multiple displays, the scanout surface is sized
57  * according to the largest width/height (so it is large enough for all CRTCs
58  * to scanout).  But the fbdev width/height is sized to the minimum width/
59  * height of all the displays.  This ensures that fbcon fits on the smallest
60  * of the attached displays. fb_width/fb_height is used by
61  * drm_fb_helper_fill_info() to fill out the &fb_info.var structure.
62  */
63 struct drm_fb_helper_surface_size {
64 	u32 fb_width;
65 	u32 fb_height;
66 	u32 surface_width;
67 	u32 surface_height;
68 	u32 surface_bpp;
69 	u32 surface_depth;
70 };
71 
72 /**
73  * struct drm_fb_helper_funcs - driver callbacks for the fbdev emulation library
74  *
75  * Driver callbacks used by the fbdev emulation helper library.
76  */
77 struct drm_fb_helper_funcs {
78 	/**
79 	 * @fb_probe:
80 	 *
81 	 * Driver callback to allocate and initialize the fbdev info structure.
82 	 * Furthermore it also needs to allocate the DRM framebuffer used to
83 	 * back the fbdev.
84 	 *
85 	 * This callback is mandatory.
86 	 *
87 	 * RETURNS:
88 	 *
89 	 * The driver should return 0 on success and a negative error code on
90 	 * failure.
91 	 */
92 	int (*fb_probe)(struct drm_fb_helper *helper,
93 			struct drm_fb_helper_surface_size *sizes);
94 };
95 
96 /**
97  * struct drm_fb_helper - main structure to emulate fbdev on top of KMS
98  * @fb: Scanout framebuffer object
99  * @dev: DRM device
100  * @funcs: driver callbacks for fb helper
101  * @fbdev: emulated fbdev device info struct
102  * @pseudo_palette: fake palette of 16 colors
103  * @dirty_clip: clip rectangle used with deferred_io to accumulate damage to
104  *              the screen buffer
105  * @dirty_lock: spinlock protecting @dirty_clip
106  * @dirty_work: worker used to flush the framebuffer
107  * @resume_work: worker used during resume if the console lock is already taken
108  *
109  * This is the main structure used by the fbdev helpers. Drivers supporting
110  * fbdev emulation should embedded this into their overall driver structure.
111  * Drivers must also fill out a &struct drm_fb_helper_funcs with a few
112  * operations.
113  */
114 struct drm_fb_helper {
115 	/**
116 	 * @client:
117 	 *
118 	 * DRM client used by the generic fbdev emulation.
119 	 */
120 	struct drm_client_dev client;
121 
122 	/**
123 	 * @buffer:
124 	 *
125 	 * Framebuffer used by the generic fbdev emulation.
126 	 */
127 	struct drm_client_buffer *buffer;
128 
129 	struct drm_framebuffer *fb;
130 	struct drm_device *dev;
131 	const struct drm_fb_helper_funcs *funcs;
132 	struct fb_info *fbdev;
133 	u32 pseudo_palette[17];
134 	struct drm_clip_rect dirty_clip;
135 	spinlock_t dirty_lock;
136 	struct work_struct dirty_work;
137 	struct work_struct resume_work;
138 
139 	/**
140 	 * @lock:
141 	 *
142 	 * Top-level FBDEV helper lock. This protects all internal data
143 	 * structures and lists, such as @connector_info and @crtc_info.
144 	 *
145 	 * FIXME: fbdev emulation locking is a mess and long term we want to
146 	 * protect all helper internal state with this lock as well as reduce
147 	 * core KMS locking as much as possible.
148 	 */
149 	struct mutex lock;
150 
151 	/**
152 	 * @kernel_fb_list:
153 	 *
154 	 * Entry on the global kernel_fb_helper_list, used for kgdb entry/exit.
155 	 */
156 	struct list_head kernel_fb_list;
157 
158 	/**
159 	 * @delayed_hotplug:
160 	 *
161 	 * A hotplug was received while fbdev wasn't in control of the DRM
162 	 * device, i.e. another KMS master was active. The output configuration
163 	 * needs to be reprobe when fbdev is in control again.
164 	 */
165 	bool delayed_hotplug;
166 
167 	/**
168 	 * @deferred_setup:
169 	 *
170 	 * If no outputs are connected (disconnected or unknown) the FB helper
171 	 * code will defer setup until at least one of the outputs shows up.
172 	 * This field keeps track of the status so that setup can be retried
173 	 * at every hotplug event until it succeeds eventually.
174 	 *
175 	 * Protected by @lock.
176 	 */
177 	bool deferred_setup;
178 
179 	/**
180 	 * @preferred_bpp:
181 	 *
182 	 * Temporary storage for the driver's preferred BPP setting passed to
183 	 * FB helper initialization. This needs to be tracked so that deferred
184 	 * FB helper setup can pass this on.
185 	 *
186 	 * See also: @deferred_setup
187 	 */
188 	int preferred_bpp;
189 };
190 
191 static inline struct drm_fb_helper *
192 drm_fb_helper_from_client(struct drm_client_dev *client)
193 {
194 	return container_of(client, struct drm_fb_helper, client);
195 }
196 
197 /**
198  * define DRM_FB_HELPER_DEFAULT_OPS - helper define for drm drivers
199  *
200  * Helper define to register default implementations of drm_fb_helper
201  * functions. To be used in struct fb_ops of drm drivers.
202  */
203 #define DRM_FB_HELPER_DEFAULT_OPS \
204 	.fb_check_var	= drm_fb_helper_check_var, \
205 	.fb_set_par	= drm_fb_helper_set_par, \
206 	.fb_setcmap	= drm_fb_helper_setcmap, \
207 	.fb_blank	= drm_fb_helper_blank, \
208 	.fb_pan_display	= drm_fb_helper_pan_display, \
209 	.fb_debug_enter = drm_fb_helper_debug_enter, \
210 	.fb_debug_leave = drm_fb_helper_debug_leave, \
211 	.fb_ioctl	= drm_fb_helper_ioctl
212 
213 #ifdef CONFIG_DRM_FBDEV_EMULATION
214 void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
215 			   const struct drm_fb_helper_funcs *funcs);
216 int drm_fb_helper_init(struct drm_device *dev, struct drm_fb_helper *helper);
217 void drm_fb_helper_fini(struct drm_fb_helper *helper);
218 int drm_fb_helper_blank(int blank, struct fb_info *info);
219 int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
220 			      struct fb_info *info);
221 int drm_fb_helper_set_par(struct fb_info *info);
222 int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
223 			    struct fb_info *info);
224 
225 int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper);
226 
227 struct fb_info *drm_fb_helper_alloc_fbi(struct drm_fb_helper *fb_helper);
228 void drm_fb_helper_unregister_fbi(struct drm_fb_helper *fb_helper);
229 void drm_fb_helper_fill_info(struct fb_info *info,
230 			     struct drm_fb_helper *fb_helper,
231 			     struct drm_fb_helper_surface_size *sizes);
232 
233 void drm_fb_helper_deferred_io(struct fb_info *info,
234 			       struct list_head *pagelist);
235 
236 ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
237 			       size_t count, loff_t *ppos);
238 ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
239 				size_t count, loff_t *ppos);
240 
241 void drm_fb_helper_sys_fillrect(struct fb_info *info,
242 				const struct fb_fillrect *rect);
243 void drm_fb_helper_sys_copyarea(struct fb_info *info,
244 				const struct fb_copyarea *area);
245 void drm_fb_helper_sys_imageblit(struct fb_info *info,
246 				 const struct fb_image *image);
247 
248 void drm_fb_helper_cfb_fillrect(struct fb_info *info,
249 				const struct fb_fillrect *rect);
250 void drm_fb_helper_cfb_copyarea(struct fb_info *info,
251 				const struct fb_copyarea *area);
252 void drm_fb_helper_cfb_imageblit(struct fb_info *info,
253 				 const struct fb_image *image);
254 
255 void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend);
256 void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
257 					bool suspend);
258 
259 int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info);
260 
261 int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
262 			unsigned long arg);
263 
264 int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper);
265 int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel);
266 int drm_fb_helper_debug_enter(struct fb_info *info);
267 int drm_fb_helper_debug_leave(struct fb_info *info);
268 
269 void drm_fb_helper_lastclose(struct drm_device *dev);
270 void drm_fb_helper_output_poll_changed(struct drm_device *dev);
271 
272 int drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp);
273 #else
274 static inline void drm_fb_helper_prepare(struct drm_device *dev,
275 					struct drm_fb_helper *helper,
276 					const struct drm_fb_helper_funcs *funcs)
277 {
278 }
279 
280 static inline int drm_fb_helper_init(struct drm_device *dev,
281 		       struct drm_fb_helper *helper)
282 {
283 	/* So drivers can use it to free the struct */
284 	helper->dev = dev;
285 	dev->fb_helper = helper;
286 
287 	return 0;
288 }
289 
290 static inline void drm_fb_helper_fini(struct drm_fb_helper *helper)
291 {
292 	if (helper && helper->dev)
293 		helper->dev->fb_helper = NULL;
294 }
295 
296 static inline int drm_fb_helper_blank(int blank, struct fb_info *info)
297 {
298 	return 0;
299 }
300 
301 static inline int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
302 					    struct fb_info *info)
303 {
304 	return 0;
305 }
306 
307 static inline int drm_fb_helper_set_par(struct fb_info *info)
308 {
309 	return 0;
310 }
311 
312 static inline int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
313 					  struct fb_info *info)
314 {
315 	return 0;
316 }
317 
318 static inline int
319 drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
320 {
321 	return 0;
322 }
323 
324 static inline struct fb_info *
325 drm_fb_helper_alloc_fbi(struct drm_fb_helper *fb_helper)
326 {
327 	return NULL;
328 }
329 
330 static inline void drm_fb_helper_unregister_fbi(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 static inline void drm_fb_helper_deferred_io(struct fb_info *info,
354 					     struct list_head *pagelist)
355 {
356 }
357 
358 static inline int drm_fb_helper_defio_init(struct drm_fb_helper *fb_helper)
359 {
360 	return -ENODEV;
361 }
362 
363 static inline ssize_t drm_fb_helper_sys_read(struct fb_info *info,
364 					     char __user *buf, size_t count,
365 					     loff_t *ppos)
366 {
367 	return -ENODEV;
368 }
369 
370 static inline ssize_t drm_fb_helper_sys_write(struct fb_info *info,
371 					      const char __user *buf,
372 					      size_t count, loff_t *ppos)
373 {
374 	return -ENODEV;
375 }
376 
377 static inline void drm_fb_helper_sys_fillrect(struct fb_info *info,
378 					      const struct fb_fillrect *rect)
379 {
380 }
381 
382 static inline void drm_fb_helper_sys_copyarea(struct fb_info *info,
383 					      const struct fb_copyarea *area)
384 {
385 }
386 
387 static inline void drm_fb_helper_sys_imageblit(struct fb_info *info,
388 					       const struct fb_image *image)
389 {
390 }
391 
392 static inline void drm_fb_helper_cfb_fillrect(struct fb_info *info,
393 					      const struct fb_fillrect *rect)
394 {
395 }
396 
397 static inline void drm_fb_helper_cfb_copyarea(struct fb_info *info,
398 					      const struct fb_copyarea *area)
399 {
400 }
401 
402 static inline void drm_fb_helper_cfb_imageblit(struct fb_info *info,
403 					       const struct fb_image *image)
404 {
405 }
406 
407 static inline void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper,
408 					     bool suspend)
409 {
410 }
411 
412 static inline void
413 drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper, bool suspend)
414 {
415 }
416 
417 static inline int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
418 {
419 	return 0;
420 }
421 
422 static inline int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper,
423 					       int bpp_sel)
424 {
425 	return 0;
426 }
427 
428 static inline int drm_fb_helper_debug_enter(struct fb_info *info)
429 {
430 	return 0;
431 }
432 
433 static inline int drm_fb_helper_debug_leave(struct fb_info *info)
434 {
435 	return 0;
436 }
437 
438 static inline void drm_fb_helper_lastclose(struct drm_device *dev)
439 {
440 }
441 
442 static inline void drm_fb_helper_output_poll_changed(struct drm_device *dev)
443 {
444 }
445 
446 static inline int
447 drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp)
448 {
449 	return 0;
450 }
451 
452 #endif
453 
454 /**
455  * drm_fb_helper_remove_conflicting_framebuffers - remove firmware-configured framebuffers
456  * @a: memory range, users of which are to be removed
457  * @name: requesting driver name
458  * @primary: also kick vga16fb if present
459  *
460  * This function removes framebuffer devices (initialized by firmware/bootloader)
461  * which use memory range described by @a. If @a is NULL all such devices are
462  * removed.
463  */
464 static inline int
465 drm_fb_helper_remove_conflicting_framebuffers(struct apertures_struct *a,
466 					      const char *name, bool primary)
467 {
468 #if IS_REACHABLE(CONFIG_FB)
469 	return remove_conflicting_framebuffers(a, name, primary);
470 #else
471 	return 0;
472 #endif
473 }
474 
475 /**
476  * drm_fb_helper_remove_conflicting_pci_framebuffers - remove firmware-configured framebuffers for PCI devices
477  * @pdev: PCI device
478  * @name: requesting driver name
479  *
480  * This function removes framebuffer devices (eg. initialized by firmware)
481  * using memory range configured for any of @pdev's memory bars.
482  *
483  * The function assumes that PCI device with shadowed ROM drives a primary
484  * display and so kicks out vga16fb.
485  */
486 static inline int
487 drm_fb_helper_remove_conflicting_pci_framebuffers(struct pci_dev *pdev,
488 						  const char *name)
489 {
490 	int ret = 0;
491 
492 	/*
493 	 * WARNING: Apparently we must kick fbdev drivers before vgacon,
494 	 * otherwise the vga fbdev driver falls over.
495 	 */
496 #if IS_REACHABLE(CONFIG_FB)
497 	ret = remove_conflicting_pci_framebuffers(pdev, name);
498 #endif
499 	if (ret == 0)
500 		ret = vga_remove_vgacon(pdev);
501 	return ret;
502 }
503 
504 #endif
505