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
33struct drm_clip_rect;
34struct 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 */
57struct 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 */
71struct 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 */
122struct 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
211static inline struct drm_fb_helper *
212drm_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
234void 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);
237void drm_fb_helper_unprepare(struct drm_fb_helper *fb_helper);
238int drm_fb_helper_init(struct drm_device *dev, struct drm_fb_helper *helper);
239void drm_fb_helper_fini(struct drm_fb_helper *helper);
240int drm_fb_helper_blank(int blank, struct fb_info *info);
241int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
242			      struct fb_info *info);
243int drm_fb_helper_set_par(struct fb_info *info);
244int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
245			    struct fb_info *info);
246
247int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper);
248
249struct fb_info *drm_fb_helper_alloc_info(struct drm_fb_helper *fb_helper);
250void drm_fb_helper_release_info(struct drm_fb_helper *fb_helper);
251void drm_fb_helper_unregister_info(struct drm_fb_helper *fb_helper);
252void 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
256void drm_fb_helper_damage_range(struct fb_info *info, off_t off, size_t len);
257void drm_fb_helper_damage_area(struct fb_info *info, u32 x, u32 y, u32 width, u32 height);
258
259void drm_fb_helper_deferred_io(struct fb_info *info, struct list_head *pagereflist);
260
261void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend);
262void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
263					bool suspend);
264
265int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info);
266
267int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
268			unsigned long arg);
269
270int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper);
271int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper);
272int drm_fb_helper_debug_enter(struct fb_info *info);
273int drm_fb_helper_debug_leave(struct fb_info *info);
274
275void drm_fb_helper_lastclose(struct drm_device *dev);
276void drm_fb_helper_output_poll_changed(struct drm_device *dev);
277#else
278static inline void drm_fb_helper_prepare(struct drm_device *dev,
279					 struct drm_fb_helper *helper,
280					 unsigned int preferred_bpp,
281					 const struct drm_fb_helper_funcs *funcs)
282{
283}
284
285static inline void drm_fb_helper_unprepare(struct drm_fb_helper *fb_helper)
286{
287}
288
289static inline int drm_fb_helper_init(struct drm_device *dev,
290		       struct drm_fb_helper *helper)
291{
292	/* So drivers can use it to free the struct */
293	helper->dev = dev;
294	dev->fb_helper = helper;
295
296	return 0;
297}
298
299static inline void drm_fb_helper_fini(struct drm_fb_helper *helper)
300{
301	if (helper && helper->dev)
302		helper->dev->fb_helper = NULL;
303}
304
305static inline int drm_fb_helper_blank(int blank, struct fb_info *info)
306{
307	return 0;
308}
309
310static inline int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
311					    struct fb_info *info)
312{
313	return 0;
314}
315
316static inline int drm_fb_helper_set_par(struct fb_info *info)
317{
318	return 0;
319}
320
321static inline int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
322					  struct fb_info *info)
323{
324	return 0;
325}
326
327static inline int
328drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
329{
330	return 0;
331}
332
333static inline struct fb_info *
334drm_fb_helper_alloc_info(struct drm_fb_helper *fb_helper)
335{
336	return NULL;
337}
338
339static inline void drm_fb_helper_release_info(struct drm_fb_helper *fb_helper)
340{
341}
342
343static inline void drm_fb_helper_unregister_info(struct drm_fb_helper *fb_helper)
344{
345}
346
347static inline void
348drm_fb_helper_fill_info(struct fb_info *info,
349			struct drm_fb_helper *fb_helper,
350			struct drm_fb_helper_surface_size *sizes)
351{
352}
353
354static inline int drm_fb_helper_setcmap(struct fb_cmap *cmap,
355					struct fb_info *info)
356{
357	return 0;
358}
359
360static inline int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
361				      unsigned long arg)
362{
363	return 0;
364}
365
366static inline void drm_fb_helper_deferred_io(struct fb_info *info,
367					     struct list_head *pagelist)
368{
369}
370
371static inline void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper,
372					     bool suspend)
373{
374}
375
376static inline void
377drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper, bool suspend)
378{
379}
380
381static inline int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
382{
383	return 0;
384}
385
386static inline int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper)
387{
388	return 0;
389}
390
391static inline int drm_fb_helper_debug_enter(struct fb_info *info)
392{
393	return 0;
394}
395
396static inline int drm_fb_helper_debug_leave(struct fb_info *info)
397{
398	return 0;
399}
400
401static inline void drm_fb_helper_lastclose(struct drm_device *dev)
402{
403}
404
405static inline void drm_fb_helper_output_poll_changed(struct drm_device *dev)
406{
407}
408#endif
409
410#endif
411