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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
31
32#include <linux/console.h>
33#include <linux/pci.h>
34#include <linux/sysrq.h>
35#include <linux/vga_switcheroo.h>
36
37#include <drm/drm_atomic.h>
38#include <drm/drm_drv.h>
39#include <drm/drm_fb_helper.h>
40#include <drm/drm_fourcc.h>
41#include <drm/drm_framebuffer.h>
42#include <drm/drm_modeset_helper_vtables.h>
43#include <drm/drm_print.h>
44#include <drm/drm_vblank.h>
45
46#include "drm_internal.h"
47
48static bool drm_fbdev_emulation = true;
49module_param_named(fbdev_emulation, drm_fbdev_emulation, bool, 0600);
50MODULE_PARM_DESC(fbdev_emulation,
51 "Enable legacy fbdev emulation [default=true]");
52
53static int drm_fbdev_overalloc = CONFIG_DRM_FBDEV_OVERALLOC;
54module_param(drm_fbdev_overalloc, int, 0444);
55MODULE_PARM_DESC(drm_fbdev_overalloc,
56 "Overallocation of the fbdev buffer (%) [default="
57 __MODULE_STRING(CONFIG_DRM_FBDEV_OVERALLOC) "]");
58
59/*
60 * In order to keep user-space compatibility, we want in certain use-cases
61 * to keep leaking the fbdev physical address to the user-space program
62 * handling the fbdev buffer.
63 *
64 * This is a bad habit, essentially kept to support closed-source OpenGL
65 * drivers that should really be moved into open-source upstream projects
66 * instead of using legacy physical addresses in user space to communicate
67 * with other out-of-tree kernel modules.
68 *
69 * This module_param *should* be removed as soon as possible and be
70 * considered as a broken and legacy behaviour from a modern fbdev device.
71 */
72static bool drm_leak_fbdev_smem;
73#if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
74module_param_unsafe(drm_leak_fbdev_smem, bool, 0600);
75MODULE_PARM_DESC(drm_leak_fbdev_smem,
76 "Allow unsafe leaking fbdev physical smem address [default=false]");
77#endif
78
79static LIST_HEAD(kernel_fb_helper_list);
80static DEFINE_MUTEX(kernel_fb_helper_lock);
81
82/**
83 * DOC: fbdev helpers
84 *
85 * The fb helper functions are useful to provide an fbdev on top of a drm kernel
86 * mode setting driver. They can be used mostly independently from the crtc
87 * helper functions used by many drivers to implement the kernel mode setting
88 * interfaces.
89 *
90 * Drivers that support a dumb buffer with a virtual address and mmap support,
91 * should try out the generic fbdev emulation using drm_fbdev_generic_setup().
92 * It will automatically set up deferred I/O if the driver requires a shadow
93 * buffer.
94 *
95 * Existing fbdev implementations should restore the fbdev console by using
96 * drm_fb_helper_lastclose() as their &drm_driver.lastclose callback.
97 * They should also notify the fb helper code from updates to the output
98 * configuration by using drm_fb_helper_output_poll_changed() as their
99 * &drm_mode_config_funcs.output_poll_changed callback. New implementations
100 * of fbdev should be build on top of struct &drm_client_funcs, which handles
101 * this automatically. Setting the old callbacks should be avoided.
102 *
103 * For suspend/resume consider using drm_mode_config_helper_suspend() and
104 * drm_mode_config_helper_resume() which takes care of fbdev as well.
105 *
106 * All other functions exported by the fb helper library can be used to
107 * implement the fbdev driver interface by the driver.
108 *
109 * It is possible, though perhaps somewhat tricky, to implement race-free
110 * hotplug detection using the fbdev helpers. The drm_fb_helper_prepare()
111 * helper must be called first to initialize the minimum required to make
112 * hotplug detection work. Drivers also need to make sure to properly set up
113 * the &drm_mode_config.funcs member. After calling drm_kms_helper_poll_init()
114 * it is safe to enable interrupts and start processing hotplug events. At the
115 * same time, drivers should initialize all modeset objects such as CRTCs,
116 * encoders and connectors. To finish up the fbdev helper initialization, the
117 * drm_fb_helper_init() function is called. To probe for all attached displays
118 * and set up an initial configuration using the detected hardware, drivers
119 * should call drm_fb_helper_initial_config().
120 *
121 * If &drm_framebuffer_funcs.dirty is set, the
122 * drm_fb_helper_{cfb,sys}_{write,fillrect,copyarea,imageblit} functions will
123 * accumulate changes and schedule &drm_fb_helper.dirty_work to run right
124 * away. This worker then calls the dirty() function ensuring that it will
125 * always run in process context since the fb_*() function could be running in
126 * atomic context. If drm_fb_helper_deferred_io() is used as the deferred_io
127 * callback it will also schedule dirty_work with the damage collected from the
128 * mmap page writes.
129 *
130 * Deferred I/O is not compatible with SHMEM. Such drivers should request an
131 * fbdev shadow buffer and call drm_fbdev_generic_setup() instead.
132 */
133
134static void drm_fb_helper_restore_lut_atomic(struct drm_crtc *crtc)
135{
136 uint16_t *r_base, *g_base, *b_base;
137
138 if (crtc->funcs->gamma_set == NULL)
139 return;
140
141 r_base = crtc->gamma_store;
142 g_base = r_base + crtc->gamma_size;
143 b_base = g_base + crtc->gamma_size;
144
145 crtc->funcs->gamma_set(crtc, r_base, g_base, b_base,
146 crtc->gamma_size, NULL);
147}
148
149/**
150 * drm_fb_helper_debug_enter - implementation for &fb_ops.fb_debug_enter
151 * @info: fbdev registered by the helper
152 */
153int drm_fb_helper_debug_enter(struct fb_info *info)
154{
155 struct drm_fb_helper *helper = info->par;
156 const struct drm_crtc_helper_funcs *funcs;
157 struct drm_mode_set *mode_set;
158
159 list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
160 mutex_lock(&helper->client.modeset_mutex);
161 drm_client_for_each_modeset(mode_set, &helper->client) {
162 if (!mode_set->crtc->enabled)
163 continue;
164
165 funcs = mode_set->crtc->helper_private;
166 if (funcs->mode_set_base_atomic == NULL)
167 continue;
168
169 if (drm_drv_uses_atomic_modeset(dev: mode_set->crtc->dev))
170 continue;
171
172 funcs->mode_set_base_atomic(mode_set->crtc,
173 mode_set->fb,
174 mode_set->x,
175 mode_set->y,
176 ENTER_ATOMIC_MODE_SET);
177 }
178 mutex_unlock(lock: &helper->client.modeset_mutex);
179 }
180
181 return 0;
182}
183EXPORT_SYMBOL(drm_fb_helper_debug_enter);
184
185/**
186 * drm_fb_helper_debug_leave - implementation for &fb_ops.fb_debug_leave
187 * @info: fbdev registered by the helper
188 */
189int drm_fb_helper_debug_leave(struct fb_info *info)
190{
191 struct drm_fb_helper *helper = info->par;
192 struct drm_client_dev *client = &helper->client;
193 struct drm_device *dev = helper->dev;
194 struct drm_crtc *crtc;
195 const struct drm_crtc_helper_funcs *funcs;
196 struct drm_mode_set *mode_set;
197 struct drm_framebuffer *fb;
198
199 mutex_lock(&client->modeset_mutex);
200 drm_client_for_each_modeset(mode_set, client) {
201 crtc = mode_set->crtc;
202 if (drm_drv_uses_atomic_modeset(dev: crtc->dev))
203 continue;
204
205 funcs = crtc->helper_private;
206 fb = crtc->primary->fb;
207
208 if (!crtc->enabled)
209 continue;
210
211 if (!fb) {
212 drm_err(dev, "no fb to restore?\n");
213 continue;
214 }
215
216 if (funcs->mode_set_base_atomic == NULL)
217 continue;
218
219 drm_fb_helper_restore_lut_atomic(crtc: mode_set->crtc);
220 funcs->mode_set_base_atomic(mode_set->crtc, fb, crtc->x,
221 crtc->y, LEAVE_ATOMIC_MODE_SET);
222 }
223 mutex_unlock(lock: &client->modeset_mutex);
224
225 return 0;
226}
227EXPORT_SYMBOL(drm_fb_helper_debug_leave);
228
229static int
230__drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper,
231 bool force)
232{
233 bool do_delayed;
234 int ret;
235
236 if (!drm_fbdev_emulation || !fb_helper)
237 return -ENODEV;
238
239 if (READ_ONCE(fb_helper->deferred_setup))
240 return 0;
241
242 mutex_lock(&fb_helper->lock);
243 if (force) {
244 /*
245 * Yes this is the _locked version which expects the master lock
246 * to be held. But for forced restores we're intentionally
247 * racing here, see drm_fb_helper_set_par().
248 */
249 ret = drm_client_modeset_commit_locked(client: &fb_helper->client);
250 } else {
251 ret = drm_client_modeset_commit(client: &fb_helper->client);
252 }
253
254 do_delayed = fb_helper->delayed_hotplug;
255 if (do_delayed)
256 fb_helper->delayed_hotplug = false;
257 mutex_unlock(lock: &fb_helper->lock);
258
259 if (do_delayed)
260 drm_fb_helper_hotplug_event(fb_helper);
261
262 return ret;
263}
264
265/**
266 * drm_fb_helper_restore_fbdev_mode_unlocked - restore fbdev configuration
267 * @fb_helper: driver-allocated fbdev helper, can be NULL
268 *
269 * This should be called from driver's drm &drm_driver.lastclose callback
270 * when implementing an fbcon on top of kms using this helper. This ensures that
271 * the user isn't greeted with a black screen when e.g. X dies.
272 *
273 * RETURNS:
274 * Zero if everything went ok, negative error code otherwise.
275 */
276int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
277{
278 return __drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper, force: false);
279}
280EXPORT_SYMBOL(drm_fb_helper_restore_fbdev_mode_unlocked);
281
282#ifdef CONFIG_MAGIC_SYSRQ
283/* emergency restore, don't bother with error reporting */
284static void drm_fb_helper_restore_work_fn(struct work_struct *ignored)
285{
286 struct drm_fb_helper *helper;
287
288 mutex_lock(&kernel_fb_helper_lock);
289 list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
290 struct drm_device *dev = helper->dev;
291
292 if (dev->switch_power_state == DRM_SWITCH_POWER_OFF)
293 continue;
294
295 mutex_lock(&helper->lock);
296 drm_client_modeset_commit_locked(client: &helper->client);
297 mutex_unlock(lock: &helper->lock);
298 }
299 mutex_unlock(lock: &kernel_fb_helper_lock);
300}
301
302static DECLARE_WORK(drm_fb_helper_restore_work, drm_fb_helper_restore_work_fn);
303
304static void drm_fb_helper_sysrq(u8 dummy1)
305{
306 schedule_work(work: &drm_fb_helper_restore_work);
307}
308
309static const struct sysrq_key_op sysrq_drm_fb_helper_restore_op = {
310 .handler = drm_fb_helper_sysrq,
311 .help_msg = "force-fb(v)",
312 .action_msg = "Restore framebuffer console",
313};
314#else
315static const struct sysrq_key_op sysrq_drm_fb_helper_restore_op = { };
316#endif
317
318static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode)
319{
320 struct drm_fb_helper *fb_helper = info->par;
321
322 mutex_lock(&fb_helper->lock);
323 drm_client_modeset_dpms(client: &fb_helper->client, mode: dpms_mode);
324 mutex_unlock(lock: &fb_helper->lock);
325}
326
327/**
328 * drm_fb_helper_blank - implementation for &fb_ops.fb_blank
329 * @blank: desired blanking state
330 * @info: fbdev registered by the helper
331 */
332int drm_fb_helper_blank(int blank, struct fb_info *info)
333{
334 if (oops_in_progress)
335 return -EBUSY;
336
337 switch (blank) {
338 /* Display: On; HSync: On, VSync: On */
339 case FB_BLANK_UNBLANK:
340 drm_fb_helper_dpms(info, DRM_MODE_DPMS_ON);
341 break;
342 /* Display: Off; HSync: On, VSync: On */
343 case FB_BLANK_NORMAL:
344 drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
345 break;
346 /* Display: Off; HSync: Off, VSync: On */
347 case FB_BLANK_HSYNC_SUSPEND:
348 drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
349 break;
350 /* Display: Off; HSync: On, VSync: Off */
351 case FB_BLANK_VSYNC_SUSPEND:
352 drm_fb_helper_dpms(info, DRM_MODE_DPMS_SUSPEND);
353 break;
354 /* Display: Off; HSync: Off, VSync: Off */
355 case FB_BLANK_POWERDOWN:
356 drm_fb_helper_dpms(info, DRM_MODE_DPMS_OFF);
357 break;
358 }
359 return 0;
360}
361EXPORT_SYMBOL(drm_fb_helper_blank);
362
363static void drm_fb_helper_resume_worker(struct work_struct *work)
364{
365 struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper,
366 resume_work);
367
368 console_lock();
369 fb_set_suspend(info: helper->info, state: 0);
370 console_unlock();
371}
372
373static void drm_fb_helper_fb_dirty(struct drm_fb_helper *helper)
374{
375 struct drm_device *dev = helper->dev;
376 struct drm_clip_rect *clip = &helper->damage_clip;
377 struct drm_clip_rect clip_copy;
378 unsigned long flags;
379 int ret;
380
381 if (drm_WARN_ON_ONCE(dev, !helper->funcs->fb_dirty))
382 return;
383
384 spin_lock_irqsave(&helper->damage_lock, flags);
385 clip_copy = *clip;
386 clip->x1 = clip->y1 = ~0;
387 clip->x2 = clip->y2 = 0;
388 spin_unlock_irqrestore(lock: &helper->damage_lock, flags);
389
390 ret = helper->funcs->fb_dirty(helper, &clip_copy);
391 if (ret)
392 goto err;
393
394 return;
395
396err:
397 /*
398 * Restore damage clip rectangle on errors. The next run
399 * of the damage worker will perform the update.
400 */
401 spin_lock_irqsave(&helper->damage_lock, flags);
402 clip->x1 = min_t(u32, clip->x1, clip_copy.x1);
403 clip->y1 = min_t(u32, clip->y1, clip_copy.y1);
404 clip->x2 = max_t(u32, clip->x2, clip_copy.x2);
405 clip->y2 = max_t(u32, clip->y2, clip_copy.y2);
406 spin_unlock_irqrestore(lock: &helper->damage_lock, flags);
407}
408
409static void drm_fb_helper_damage_work(struct work_struct *work)
410{
411 struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper, damage_work);
412
413 drm_fb_helper_fb_dirty(helper);
414}
415
416/**
417 * drm_fb_helper_prepare - setup a drm_fb_helper structure
418 * @dev: DRM device
419 * @helper: driver-allocated fbdev helper structure to set up
420 * @preferred_bpp: Preferred bits per pixel for the device.
421 * @funcs: pointer to structure of functions associate with this helper
422 *
423 * Sets up the bare minimum to make the framebuffer helper usable. This is
424 * useful to implement race-free initialization of the polling helpers.
425 */
426void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
427 unsigned int preferred_bpp,
428 const struct drm_fb_helper_funcs *funcs)
429{
430 /*
431 * Pick a preferred bpp of 32 if no value has been given. This
432 * will select XRGB8888 for the framebuffer formats. All drivers
433 * have to support XRGB8888 for backwards compatibility with legacy
434 * userspace, so it's the safe choice here.
435 *
436 * TODO: Replace struct drm_mode_config.preferred_depth and this
437 * bpp value with a preferred format that is given as struct
438 * drm_format_info. Then derive all other values from the
439 * format.
440 */
441 if (!preferred_bpp)
442 preferred_bpp = 32;
443
444 INIT_LIST_HEAD(list: &helper->kernel_fb_list);
445 spin_lock_init(&helper->damage_lock);
446 INIT_WORK(&helper->resume_work, drm_fb_helper_resume_worker);
447 INIT_WORK(&helper->damage_work, drm_fb_helper_damage_work);
448 helper->damage_clip.x1 = helper->damage_clip.y1 = ~0;
449 mutex_init(&helper->lock);
450 helper->funcs = funcs;
451 helper->dev = dev;
452 helper->preferred_bpp = preferred_bpp;
453}
454EXPORT_SYMBOL(drm_fb_helper_prepare);
455
456/**
457 * drm_fb_helper_unprepare - clean up a drm_fb_helper structure
458 * @fb_helper: driver-allocated fbdev helper structure to set up
459 *
460 * Cleans up the framebuffer helper. Inverse of drm_fb_helper_prepare().
461 */
462void drm_fb_helper_unprepare(struct drm_fb_helper *fb_helper)
463{
464 mutex_destroy(lock: &fb_helper->lock);
465}
466EXPORT_SYMBOL(drm_fb_helper_unprepare);
467
468/**
469 * drm_fb_helper_init - initialize a &struct drm_fb_helper
470 * @dev: drm device
471 * @fb_helper: driver-allocated fbdev helper structure to initialize
472 *
473 * This allocates the structures for the fbdev helper with the given limits.
474 * Note that this won't yet touch the hardware (through the driver interfaces)
475 * nor register the fbdev. This is only done in drm_fb_helper_initial_config()
476 * to allow driver writes more control over the exact init sequence.
477 *
478 * Drivers must call drm_fb_helper_prepare() before calling this function.
479 *
480 * RETURNS:
481 * Zero if everything went ok, nonzero otherwise.
482 */
483int drm_fb_helper_init(struct drm_device *dev,
484 struct drm_fb_helper *fb_helper)
485{
486 int ret;
487
488 /*
489 * If this is not the generic fbdev client, initialize a drm_client
490 * without callbacks so we can use the modesets.
491 */
492 if (!fb_helper->client.funcs) {
493 ret = drm_client_init(dev, client: &fb_helper->client, name: "drm_fb_helper", NULL);
494 if (ret)
495 return ret;
496 }
497
498 dev->fb_helper = fb_helper;
499
500 return 0;
501}
502EXPORT_SYMBOL(drm_fb_helper_init);
503
504/**
505 * drm_fb_helper_alloc_info - allocate fb_info and some of its members
506 * @fb_helper: driver-allocated fbdev helper
507 *
508 * A helper to alloc fb_info and the member cmap. Called by the driver
509 * within the fb_probe fb_helper callback function. Drivers do not
510 * need to release the allocated fb_info structure themselves, this is
511 * automatically done when calling drm_fb_helper_fini().
512 *
513 * RETURNS:
514 * fb_info pointer if things went okay, pointer containing error code
515 * otherwise
516 */
517struct fb_info *drm_fb_helper_alloc_info(struct drm_fb_helper *fb_helper)
518{
519 struct device *dev = fb_helper->dev->dev;
520 struct fb_info *info;
521 int ret;
522
523 info = framebuffer_alloc(size: 0, dev);
524 if (!info)
525 return ERR_PTR(error: -ENOMEM);
526
527 ret = fb_alloc_cmap(cmap: &info->cmap, len: 256, transp: 0);
528 if (ret)
529 goto err_release;
530
531 fb_helper->info = info;
532 info->skip_vt_switch = true;
533
534 return info;
535
536err_release:
537 framebuffer_release(info);
538 return ERR_PTR(error: ret);
539}
540EXPORT_SYMBOL(drm_fb_helper_alloc_info);
541
542/**
543 * drm_fb_helper_release_info - release fb_info and its members
544 * @fb_helper: driver-allocated fbdev helper
545 *
546 * A helper to release fb_info and the member cmap. Drivers do not
547 * need to release the allocated fb_info structure themselves, this is
548 * automatically done when calling drm_fb_helper_fini().
549 */
550void drm_fb_helper_release_info(struct drm_fb_helper *fb_helper)
551{
552 struct fb_info *info = fb_helper->info;
553
554 if (!info)
555 return;
556
557 fb_helper->info = NULL;
558
559 if (info->cmap.len)
560 fb_dealloc_cmap(cmap: &info->cmap);
561 framebuffer_release(info);
562}
563EXPORT_SYMBOL(drm_fb_helper_release_info);
564
565/**
566 * drm_fb_helper_unregister_info - unregister fb_info framebuffer device
567 * @fb_helper: driver-allocated fbdev helper, can be NULL
568 *
569 * A wrapper around unregister_framebuffer, to release the fb_info
570 * framebuffer device. This must be called before releasing all resources for
571 * @fb_helper by calling drm_fb_helper_fini().
572 */
573void drm_fb_helper_unregister_info(struct drm_fb_helper *fb_helper)
574{
575 if (fb_helper && fb_helper->info)
576 unregister_framebuffer(fb_info: fb_helper->info);
577}
578EXPORT_SYMBOL(drm_fb_helper_unregister_info);
579
580/**
581 * drm_fb_helper_fini - finialize a &struct drm_fb_helper
582 * @fb_helper: driver-allocated fbdev helper, can be NULL
583 *
584 * This cleans up all remaining resources associated with @fb_helper.
585 */
586void drm_fb_helper_fini(struct drm_fb_helper *fb_helper)
587{
588 if (!fb_helper)
589 return;
590
591 fb_helper->dev->fb_helper = NULL;
592
593 if (!drm_fbdev_emulation)
594 return;
595
596 cancel_work_sync(work: &fb_helper->resume_work);
597 cancel_work_sync(work: &fb_helper->damage_work);
598
599 drm_fb_helper_release_info(fb_helper);
600
601 mutex_lock(&kernel_fb_helper_lock);
602 if (!list_empty(head: &fb_helper->kernel_fb_list)) {
603 list_del(entry: &fb_helper->kernel_fb_list);
604 if (list_empty(head: &kernel_fb_helper_list))
605 unregister_sysrq_key(key: 'v', op: &sysrq_drm_fb_helper_restore_op);
606 }
607 mutex_unlock(lock: &kernel_fb_helper_lock);
608
609 if (!fb_helper->client.funcs)
610 drm_client_release(client: &fb_helper->client);
611}
612EXPORT_SYMBOL(drm_fb_helper_fini);
613
614static void drm_fb_helper_add_damage_clip(struct drm_fb_helper *helper, u32 x, u32 y,
615 u32 width, u32 height)
616{
617 struct drm_clip_rect *clip = &helper->damage_clip;
618 unsigned long flags;
619
620 spin_lock_irqsave(&helper->damage_lock, flags);
621 clip->x1 = min_t(u32, clip->x1, x);
622 clip->y1 = min_t(u32, clip->y1, y);
623 clip->x2 = max_t(u32, clip->x2, x + width);
624 clip->y2 = max_t(u32, clip->y2, y + height);
625 spin_unlock_irqrestore(lock: &helper->damage_lock, flags);
626}
627
628static void drm_fb_helper_damage(struct drm_fb_helper *helper, u32 x, u32 y,
629 u32 width, u32 height)
630{
631 drm_fb_helper_add_damage_clip(helper, x, y, width, height);
632
633 schedule_work(work: &helper->damage_work);
634}
635
636/*
637 * Convert memory region into area of scanlines and pixels per
638 * scanline. The parameters off and len must not reach beyond
639 * the end of the framebuffer.
640 */
641static void drm_fb_helper_memory_range_to_clip(struct fb_info *info, off_t off, size_t len,
642 struct drm_rect *clip)
643{
644 u32 line_length = info->fix.line_length;
645 u32 fb_height = info->var.yres;
646 off_t end = off + len;
647 u32 x1 = 0;
648 u32 y1 = off / line_length;
649 u32 x2 = info->var.xres;
650 u32 y2 = DIV_ROUND_UP(end, line_length);
651
652 /* Don't allow any of them beyond the bottom bound of display area */
653 if (y1 > fb_height)
654 y1 = fb_height;
655 if (y2 > fb_height)
656 y2 = fb_height;
657
658 if ((y2 - y1) == 1) {
659 /*
660 * We've only written to a single scanline. Try to reduce
661 * the number of horizontal pixels that need an update.
662 */
663 off_t bit_off = (off % line_length) * 8;
664 off_t bit_end = (end % line_length) * 8;
665
666 x1 = bit_off / info->var.bits_per_pixel;
667 x2 = DIV_ROUND_UP(bit_end, info->var.bits_per_pixel);
668 }
669
670 drm_rect_init(r: clip, x: x1, y: y1, width: x2 - x1, height: y2 - y1);
671}
672
673/* Don't use in new code. */
674void drm_fb_helper_damage_range(struct fb_info *info, off_t off, size_t len)
675{
676 struct drm_fb_helper *fb_helper = info->par;
677 struct drm_rect damage_area;
678
679 drm_fb_helper_memory_range_to_clip(info, off, len, clip: &damage_area);
680 drm_fb_helper_damage(helper: fb_helper, x: damage_area.x1, y: damage_area.y1,
681 width: drm_rect_width(r: &damage_area),
682 height: drm_rect_height(r: &damage_area));
683}
684EXPORT_SYMBOL(drm_fb_helper_damage_range);
685
686/* Don't use in new code. */
687void drm_fb_helper_damage_area(struct fb_info *info, u32 x, u32 y, u32 width, u32 height)
688{
689 struct drm_fb_helper *fb_helper = info->par;
690
691 drm_fb_helper_damage(helper: fb_helper, x, y, width, height);
692}
693EXPORT_SYMBOL(drm_fb_helper_damage_area);
694
695/**
696 * drm_fb_helper_deferred_io() - fbdev deferred_io callback function
697 * @info: fb_info struct pointer
698 * @pagereflist: list of mmap framebuffer pages that have to be flushed
699 *
700 * This function is used as the &fb_deferred_io.deferred_io
701 * callback function for flushing the fbdev mmap writes.
702 */
703void drm_fb_helper_deferred_io(struct fb_info *info, struct list_head *pagereflist)
704{
705 struct drm_fb_helper *helper = info->par;
706 unsigned long start, end, min_off, max_off, total_size;
707 struct fb_deferred_io_pageref *pageref;
708 struct drm_rect damage_area;
709
710 min_off = ULONG_MAX;
711 max_off = 0;
712 list_for_each_entry(pageref, pagereflist, list) {
713 start = pageref->offset;
714 end = start + PAGE_SIZE;
715 min_off = min(min_off, start);
716 max_off = max(max_off, end);
717 }
718
719 /*
720 * As we can only track pages, we might reach beyond the end
721 * of the screen and account for non-existing scanlines. Hence,
722 * keep the covered memory area within the screen buffer.
723 */
724 if (info->screen_size)
725 total_size = info->screen_size;
726 else
727 total_size = info->fix.smem_len;
728 max_off = min(max_off, total_size);
729
730 if (min_off < max_off) {
731 drm_fb_helper_memory_range_to_clip(info, off: min_off, len: max_off - min_off, clip: &damage_area);
732 drm_fb_helper_damage(helper, x: damage_area.x1, y: damage_area.y1,
733 width: drm_rect_width(r: &damage_area),
734 height: drm_rect_height(r: &damage_area));
735 }
736}
737EXPORT_SYMBOL(drm_fb_helper_deferred_io);
738
739/**
740 * drm_fb_helper_set_suspend - wrapper around fb_set_suspend
741 * @fb_helper: driver-allocated fbdev helper, can be NULL
742 * @suspend: whether to suspend or resume
743 *
744 * A wrapper around fb_set_suspend implemented by fbdev core.
745 * Use drm_fb_helper_set_suspend_unlocked() if you don't need to take
746 * the lock yourself
747 */
748void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend)
749{
750 if (fb_helper && fb_helper->info)
751 fb_set_suspend(info: fb_helper->info, state: suspend);
752}
753EXPORT_SYMBOL(drm_fb_helper_set_suspend);
754
755/**
756 * drm_fb_helper_set_suspend_unlocked - wrapper around fb_set_suspend that also
757 * takes the console lock
758 * @fb_helper: driver-allocated fbdev helper, can be NULL
759 * @suspend: whether to suspend or resume
760 *
761 * A wrapper around fb_set_suspend() that takes the console lock. If the lock
762 * isn't available on resume, a worker is tasked with waiting for the lock
763 * to become available. The console lock can be pretty contented on resume
764 * due to all the printk activity.
765 *
766 * This function can be called multiple times with the same state since
767 * &fb_info.state is checked to see if fbdev is running or not before locking.
768 *
769 * Use drm_fb_helper_set_suspend() if you need to take the lock yourself.
770 */
771void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
772 bool suspend)
773{
774 if (!fb_helper || !fb_helper->info)
775 return;
776
777 /* make sure there's no pending/ongoing resume */
778 flush_work(work: &fb_helper->resume_work);
779
780 if (suspend) {
781 if (fb_helper->info->state != FBINFO_STATE_RUNNING)
782 return;
783
784 console_lock();
785
786 } else {
787 if (fb_helper->info->state == FBINFO_STATE_RUNNING)
788 return;
789
790 if (!console_trylock()) {
791 schedule_work(work: &fb_helper->resume_work);
792 return;
793 }
794 }
795
796 fb_set_suspend(info: fb_helper->info, state: suspend);
797 console_unlock();
798}
799EXPORT_SYMBOL(drm_fb_helper_set_suspend_unlocked);
800
801static int setcmap_pseudo_palette(struct fb_cmap *cmap, struct fb_info *info)
802{
803 u32 *palette = (u32 *)info->pseudo_palette;
804 int i;
805
806 if (cmap->start + cmap->len > 16)
807 return -EINVAL;
808
809 for (i = 0; i < cmap->len; ++i) {
810 u16 red = cmap->red[i];
811 u16 green = cmap->green[i];
812 u16 blue = cmap->blue[i];
813 u32 value;
814
815 red >>= 16 - info->var.red.length;
816 green >>= 16 - info->var.green.length;
817 blue >>= 16 - info->var.blue.length;
818 value = (red << info->var.red.offset) |
819 (green << info->var.green.offset) |
820 (blue << info->var.blue.offset);
821 if (info->var.transp.length > 0) {
822 u32 mask = (1 << info->var.transp.length) - 1;
823
824 mask <<= info->var.transp.offset;
825 value |= mask;
826 }
827 palette[cmap->start + i] = value;
828 }
829
830 return 0;
831}
832
833static int setcmap_legacy(struct fb_cmap *cmap, struct fb_info *info)
834{
835 struct drm_fb_helper *fb_helper = info->par;
836 struct drm_mode_set *modeset;
837 struct drm_crtc *crtc;
838 u16 *r, *g, *b;
839 int ret = 0;
840
841 drm_modeset_lock_all(dev: fb_helper->dev);
842 drm_client_for_each_modeset(modeset, &fb_helper->client) {
843 crtc = modeset->crtc;
844 if (!crtc->funcs->gamma_set || !crtc->gamma_size) {
845 ret = -EINVAL;
846 goto out;
847 }
848
849 if (cmap->start + cmap->len > crtc->gamma_size) {
850 ret = -EINVAL;
851 goto out;
852 }
853
854 r = crtc->gamma_store;
855 g = r + crtc->gamma_size;
856 b = g + crtc->gamma_size;
857
858 memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
859 memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
860 memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
861
862 ret = crtc->funcs->gamma_set(crtc, r, g, b,
863 crtc->gamma_size, NULL);
864 if (ret)
865 goto out;
866 }
867out:
868 drm_modeset_unlock_all(dev: fb_helper->dev);
869
870 return ret;
871}
872
873static struct drm_property_blob *setcmap_new_gamma_lut(struct drm_crtc *crtc,
874 struct fb_cmap *cmap)
875{
876 struct drm_device *dev = crtc->dev;
877 struct drm_property_blob *gamma_lut;
878 struct drm_color_lut *lut;
879 int size = crtc->gamma_size;
880 int i;
881
882 if (!size || cmap->start + cmap->len > size)
883 return ERR_PTR(error: -EINVAL);
884
885 gamma_lut = drm_property_create_blob(dev, length: sizeof(*lut) * size, NULL);
886 if (IS_ERR(ptr: gamma_lut))
887 return gamma_lut;
888
889 lut = gamma_lut->data;
890 if (cmap->start || cmap->len != size) {
891 u16 *r = crtc->gamma_store;
892 u16 *g = r + crtc->gamma_size;
893 u16 *b = g + crtc->gamma_size;
894
895 for (i = 0; i < cmap->start; i++) {
896 lut[i].red = r[i];
897 lut[i].green = g[i];
898 lut[i].blue = b[i];
899 }
900 for (i = cmap->start + cmap->len; i < size; i++) {
901 lut[i].red = r[i];
902 lut[i].green = g[i];
903 lut[i].blue = b[i];
904 }
905 }
906
907 for (i = 0; i < cmap->len; i++) {
908 lut[cmap->start + i].red = cmap->red[i];
909 lut[cmap->start + i].green = cmap->green[i];
910 lut[cmap->start + i].blue = cmap->blue[i];
911 }
912
913 return gamma_lut;
914}
915
916static int setcmap_atomic(struct fb_cmap *cmap, struct fb_info *info)
917{
918 struct drm_fb_helper *fb_helper = info->par;
919 struct drm_device *dev = fb_helper->dev;
920 struct drm_property_blob *gamma_lut = NULL;
921 struct drm_modeset_acquire_ctx ctx;
922 struct drm_crtc_state *crtc_state;
923 struct drm_atomic_state *state;
924 struct drm_mode_set *modeset;
925 struct drm_crtc *crtc;
926 u16 *r, *g, *b;
927 bool replaced;
928 int ret = 0;
929
930 drm_modeset_acquire_init(ctx: &ctx, flags: 0);
931
932 state = drm_atomic_state_alloc(dev);
933 if (!state) {
934 ret = -ENOMEM;
935 goto out_ctx;
936 }
937
938 state->acquire_ctx = &ctx;
939retry:
940 drm_client_for_each_modeset(modeset, &fb_helper->client) {
941 crtc = modeset->crtc;
942
943 if (!gamma_lut)
944 gamma_lut = setcmap_new_gamma_lut(crtc, cmap);
945 if (IS_ERR(ptr: gamma_lut)) {
946 ret = PTR_ERR(ptr: gamma_lut);
947 gamma_lut = NULL;
948 goto out_state;
949 }
950
951 crtc_state = drm_atomic_get_crtc_state(state, crtc);
952 if (IS_ERR(ptr: crtc_state)) {
953 ret = PTR_ERR(ptr: crtc_state);
954 goto out_state;
955 }
956
957 /*
958 * FIXME: This always uses gamma_lut. Some HW have only
959 * degamma_lut, in which case we should reset gamma_lut and set
960 * degamma_lut. See drm_crtc_legacy_gamma_set().
961 */
962 replaced = drm_property_replace_blob(blob: &crtc_state->degamma_lut,
963 NULL);
964 replaced |= drm_property_replace_blob(blob: &crtc_state->ctm, NULL);
965 replaced |= drm_property_replace_blob(blob: &crtc_state->gamma_lut,
966 new_blob: gamma_lut);
967 crtc_state->color_mgmt_changed |= replaced;
968 }
969
970 ret = drm_atomic_commit(state);
971 if (ret)
972 goto out_state;
973
974 drm_client_for_each_modeset(modeset, &fb_helper->client) {
975 crtc = modeset->crtc;
976
977 r = crtc->gamma_store;
978 g = r + crtc->gamma_size;
979 b = g + crtc->gamma_size;
980
981 memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
982 memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
983 memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
984 }
985
986out_state:
987 if (ret == -EDEADLK)
988 goto backoff;
989
990 drm_property_blob_put(blob: gamma_lut);
991 drm_atomic_state_put(state);
992out_ctx:
993 drm_modeset_drop_locks(ctx: &ctx);
994 drm_modeset_acquire_fini(ctx: &ctx);
995
996 return ret;
997
998backoff:
999 drm_atomic_state_clear(state);
1000 drm_modeset_backoff(ctx: &ctx);
1001 goto retry;
1002}
1003
1004/**
1005 * drm_fb_helper_setcmap - implementation for &fb_ops.fb_setcmap
1006 * @cmap: cmap to set
1007 * @info: fbdev registered by the helper
1008 */
1009int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
1010{
1011 struct drm_fb_helper *fb_helper = info->par;
1012 struct drm_device *dev = fb_helper->dev;
1013 int ret;
1014
1015 if (oops_in_progress)
1016 return -EBUSY;
1017
1018 mutex_lock(&fb_helper->lock);
1019
1020 if (!drm_master_internal_acquire(dev)) {
1021 ret = -EBUSY;
1022 goto unlock;
1023 }
1024
1025 mutex_lock(&fb_helper->client.modeset_mutex);
1026 if (info->fix.visual == FB_VISUAL_TRUECOLOR)
1027 ret = setcmap_pseudo_palette(cmap, info);
1028 else if (drm_drv_uses_atomic_modeset(dev: fb_helper->dev))
1029 ret = setcmap_atomic(cmap, info);
1030 else
1031 ret = setcmap_legacy(cmap, info);
1032 mutex_unlock(lock: &fb_helper->client.modeset_mutex);
1033
1034 drm_master_internal_release(dev);
1035unlock:
1036 mutex_unlock(lock: &fb_helper->lock);
1037
1038 return ret;
1039}
1040EXPORT_SYMBOL(drm_fb_helper_setcmap);
1041
1042/**
1043 * drm_fb_helper_ioctl - legacy ioctl implementation
1044 * @info: fbdev registered by the helper
1045 * @cmd: ioctl command
1046 * @arg: ioctl argument
1047 *
1048 * A helper to implement the standard fbdev ioctl. Only
1049 * FBIO_WAITFORVSYNC is implemented for now.
1050 */
1051int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
1052 unsigned long arg)
1053{
1054 struct drm_fb_helper *fb_helper = info->par;
1055 struct drm_device *dev = fb_helper->dev;
1056 struct drm_crtc *crtc;
1057 int ret = 0;
1058
1059 mutex_lock(&fb_helper->lock);
1060 if (!drm_master_internal_acquire(dev)) {
1061 ret = -EBUSY;
1062 goto unlock;
1063 }
1064
1065 switch (cmd) {
1066 case FBIO_WAITFORVSYNC:
1067 /*
1068 * Only consider the first CRTC.
1069 *
1070 * This ioctl is supposed to take the CRTC number as
1071 * an argument, but in fbdev times, what that number
1072 * was supposed to be was quite unclear, different
1073 * drivers were passing that argument differently
1074 * (some by reference, some by value), and most of the
1075 * userspace applications were just hardcoding 0 as an
1076 * argument.
1077 *
1078 * The first CRTC should be the integrated panel on
1079 * most drivers, so this is the best choice we can
1080 * make. If we're not smart enough here, one should
1081 * just consider switch the userspace to KMS.
1082 */
1083 crtc = fb_helper->client.modesets[0].crtc;
1084
1085 /*
1086 * Only wait for a vblank event if the CRTC is
1087 * enabled, otherwise just don't do anythintg,
1088 * not even report an error.
1089 */
1090 ret = drm_crtc_vblank_get(crtc);
1091 if (!ret) {
1092 drm_crtc_wait_one_vblank(crtc);
1093 drm_crtc_vblank_put(crtc);
1094 }
1095
1096 ret = 0;
1097 break;
1098 default:
1099 ret = -ENOTTY;
1100 }
1101
1102 drm_master_internal_release(dev);
1103unlock:
1104 mutex_unlock(lock: &fb_helper->lock);
1105 return ret;
1106}
1107EXPORT_SYMBOL(drm_fb_helper_ioctl);
1108
1109static bool drm_fb_pixel_format_equal(const struct fb_var_screeninfo *var_1,
1110 const struct fb_var_screeninfo *var_2)
1111{
1112 return var_1->bits_per_pixel == var_2->bits_per_pixel &&
1113 var_1->grayscale == var_2->grayscale &&
1114 var_1->red.offset == var_2->red.offset &&
1115 var_1->red.length == var_2->red.length &&
1116 var_1->red.msb_right == var_2->red.msb_right &&
1117 var_1->green.offset == var_2->green.offset &&
1118 var_1->green.length == var_2->green.length &&
1119 var_1->green.msb_right == var_2->green.msb_right &&
1120 var_1->blue.offset == var_2->blue.offset &&
1121 var_1->blue.length == var_2->blue.length &&
1122 var_1->blue.msb_right == var_2->blue.msb_right &&
1123 var_1->transp.offset == var_2->transp.offset &&
1124 var_1->transp.length == var_2->transp.length &&
1125 var_1->transp.msb_right == var_2->transp.msb_right;
1126}
1127
1128static void drm_fb_helper_fill_pixel_fmt(struct fb_var_screeninfo *var,
1129 const struct drm_format_info *format)
1130{
1131 u8 depth = format->depth;
1132
1133 if (format->is_color_indexed) {
1134 var->red.offset = 0;
1135 var->green.offset = 0;
1136 var->blue.offset = 0;
1137 var->red.length = depth;
1138 var->green.length = depth;
1139 var->blue.length = depth;
1140 var->transp.offset = 0;
1141 var->transp.length = 0;
1142 return;
1143 }
1144
1145 switch (depth) {
1146 case 15:
1147 var->red.offset = 10;
1148 var->green.offset = 5;
1149 var->blue.offset = 0;
1150 var->red.length = 5;
1151 var->green.length = 5;
1152 var->blue.length = 5;
1153 var->transp.offset = 15;
1154 var->transp.length = 1;
1155 break;
1156 case 16:
1157 var->red.offset = 11;
1158 var->green.offset = 5;
1159 var->blue.offset = 0;
1160 var->red.length = 5;
1161 var->green.length = 6;
1162 var->blue.length = 5;
1163 var->transp.offset = 0;
1164 break;
1165 case 24:
1166 var->red.offset = 16;
1167 var->green.offset = 8;
1168 var->blue.offset = 0;
1169 var->red.length = 8;
1170 var->green.length = 8;
1171 var->blue.length = 8;
1172 var->transp.offset = 0;
1173 var->transp.length = 0;
1174 break;
1175 case 32:
1176 var->red.offset = 16;
1177 var->green.offset = 8;
1178 var->blue.offset = 0;
1179 var->red.length = 8;
1180 var->green.length = 8;
1181 var->blue.length = 8;
1182 var->transp.offset = 24;
1183 var->transp.length = 8;
1184 break;
1185 default:
1186 break;
1187 }
1188}
1189
1190static void __fill_var(struct fb_var_screeninfo *var, struct fb_info *info,
1191 struct drm_framebuffer *fb)
1192{
1193 int i;
1194
1195 var->xres_virtual = fb->width;
1196 var->yres_virtual = fb->height;
1197 var->accel_flags = 0;
1198 var->bits_per_pixel = drm_format_info_bpp(info: fb->format, plane: 0);
1199
1200 var->height = info->var.height;
1201 var->width = info->var.width;
1202
1203 var->left_margin = var->right_margin = 0;
1204 var->upper_margin = var->lower_margin = 0;
1205 var->hsync_len = var->vsync_len = 0;
1206 var->sync = var->vmode = 0;
1207 var->rotate = 0;
1208 var->colorspace = 0;
1209 for (i = 0; i < 4; i++)
1210 var->reserved[i] = 0;
1211}
1212
1213/**
1214 * drm_fb_helper_check_var - implementation for &fb_ops.fb_check_var
1215 * @var: screeninfo to check
1216 * @info: fbdev registered by the helper
1217 */
1218int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
1219 struct fb_info *info)
1220{
1221 struct drm_fb_helper *fb_helper = info->par;
1222 struct drm_framebuffer *fb = fb_helper->fb;
1223 const struct drm_format_info *format = fb->format;
1224 struct drm_device *dev = fb_helper->dev;
1225 unsigned int bpp;
1226
1227 if (in_dbg_master())
1228 return -EINVAL;
1229
1230 if (var->pixclock != 0) {
1231 drm_dbg_kms(dev, "fbdev emulation doesn't support changing the pixel clock, value of pixclock is ignored\n");
1232 var->pixclock = 0;
1233 }
1234
1235 switch (format->format) {
1236 case DRM_FORMAT_C1:
1237 case DRM_FORMAT_C2:
1238 case DRM_FORMAT_C4:
1239 /* supported format with sub-byte pixels */
1240 break;
1241
1242 default:
1243 if ((drm_format_info_block_width(info: format, plane: 0) > 1) ||
1244 (drm_format_info_block_height(info: format, plane: 0) > 1))
1245 return -EINVAL;
1246 break;
1247 }
1248
1249 /*
1250 * Changes struct fb_var_screeninfo are currently not pushed back
1251 * to KMS, hence fail if different settings are requested.
1252 */
1253 bpp = drm_format_info_bpp(info: format, plane: 0);
1254 if (var->bits_per_pixel > bpp ||
1255 var->xres > fb->width || var->yres > fb->height ||
1256 var->xres_virtual > fb->width || var->yres_virtual > fb->height) {
1257 drm_dbg_kms(dev, "fb requested width/height/bpp can't fit in current fb "
1258 "request %dx%d-%d (virtual %dx%d) > %dx%d-%d\n",
1259 var->xres, var->yres, var->bits_per_pixel,
1260 var->xres_virtual, var->yres_virtual,
1261 fb->width, fb->height, bpp);
1262 return -EINVAL;
1263 }
1264
1265 __fill_var(var, info, fb);
1266
1267 /*
1268 * fb_pan_display() validates this, but fb_set_par() doesn't and just
1269 * falls over. Note that __fill_var above adjusts y/res_virtual.
1270 */
1271 if (var->yoffset > var->yres_virtual - var->yres ||
1272 var->xoffset > var->xres_virtual - var->xres)
1273 return -EINVAL;
1274
1275 /* We neither support grayscale nor FOURCC (also stored in here). */
1276 if (var->grayscale > 0)
1277 return -EINVAL;
1278
1279 if (var->nonstd)
1280 return -EINVAL;
1281
1282 /*
1283 * Workaround for SDL 1.2, which is known to be setting all pixel format
1284 * fields values to zero in some cases. We treat this situation as a
1285 * kind of "use some reasonable autodetected values".
1286 */
1287 if (!var->red.offset && !var->green.offset &&
1288 !var->blue.offset && !var->transp.offset &&
1289 !var->red.length && !var->green.length &&
1290 !var->blue.length && !var->transp.length &&
1291 !var->red.msb_right && !var->green.msb_right &&
1292 !var->blue.msb_right && !var->transp.msb_right) {
1293 drm_fb_helper_fill_pixel_fmt(var, format);
1294 }
1295
1296 /*
1297 * drm fbdev emulation doesn't support changing the pixel format at all,
1298 * so reject all pixel format changing requests.
1299 */
1300 if (!drm_fb_pixel_format_equal(var_1: var, var_2: &info->var)) {
1301 drm_dbg_kms(dev, "fbdev emulation doesn't support changing the pixel format\n");
1302 return -EINVAL;
1303 }
1304
1305 return 0;
1306}
1307EXPORT_SYMBOL(drm_fb_helper_check_var);
1308
1309/**
1310 * drm_fb_helper_set_par - implementation for &fb_ops.fb_set_par
1311 * @info: fbdev registered by the helper
1312 *
1313 * This will let fbcon do the mode init and is called at initialization time by
1314 * the fbdev core when registering the driver, and later on through the hotplug
1315 * callback.
1316 */
1317int drm_fb_helper_set_par(struct fb_info *info)
1318{
1319 struct drm_fb_helper *fb_helper = info->par;
1320 struct fb_var_screeninfo *var = &info->var;
1321 bool force;
1322
1323 if (oops_in_progress)
1324 return -EBUSY;
1325
1326 /*
1327 * Normally we want to make sure that a kms master takes precedence over
1328 * fbdev, to avoid fbdev flickering and occasionally stealing the
1329 * display status. But Xorg first sets the vt back to text mode using
1330 * the KDSET IOCTL with KD_TEXT, and only after that drops the master
1331 * status when exiting.
1332 *
1333 * In the past this was caught by drm_fb_helper_lastclose(), but on
1334 * modern systems where logind always keeps a drm fd open to orchestrate
1335 * the vt switching, this doesn't work.
1336 *
1337 * To not break the userspace ABI we have this special case here, which
1338 * is only used for the above case. Everything else uses the normal
1339 * commit function, which ensures that we never steal the display from
1340 * an active drm master.
1341 */
1342 force = var->activate & FB_ACTIVATE_KD_TEXT;
1343
1344 __drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper, force);
1345
1346 return 0;
1347}
1348EXPORT_SYMBOL(drm_fb_helper_set_par);
1349
1350static void pan_set(struct drm_fb_helper *fb_helper, int x, int y)
1351{
1352 struct drm_mode_set *mode_set;
1353
1354 mutex_lock(&fb_helper->client.modeset_mutex);
1355 drm_client_for_each_modeset(mode_set, &fb_helper->client) {
1356 mode_set->x = x;
1357 mode_set->y = y;
1358 }
1359 mutex_unlock(lock: &fb_helper->client.modeset_mutex);
1360}
1361
1362static int pan_display_atomic(struct fb_var_screeninfo *var,
1363 struct fb_info *info)
1364{
1365 struct drm_fb_helper *fb_helper = info->par;
1366 int ret;
1367
1368 pan_set(fb_helper, x: var->xoffset, y: var->yoffset);
1369
1370 ret = drm_client_modeset_commit_locked(client: &fb_helper->client);
1371 if (!ret) {
1372 info->var.xoffset = var->xoffset;
1373 info->var.yoffset = var->yoffset;
1374 } else
1375 pan_set(fb_helper, x: info->var.xoffset, y: info->var.yoffset);
1376
1377 return ret;
1378}
1379
1380static int pan_display_legacy(struct fb_var_screeninfo *var,
1381 struct fb_info *info)
1382{
1383 struct drm_fb_helper *fb_helper = info->par;
1384 struct drm_client_dev *client = &fb_helper->client;
1385 struct drm_mode_set *modeset;
1386 int ret = 0;
1387
1388 mutex_lock(&client->modeset_mutex);
1389 drm_modeset_lock_all(dev: fb_helper->dev);
1390 drm_client_for_each_modeset(modeset, client) {
1391 modeset->x = var->xoffset;
1392 modeset->y = var->yoffset;
1393
1394 if (modeset->num_connectors) {
1395 ret = drm_mode_set_config_internal(set: modeset);
1396 if (!ret) {
1397 info->var.xoffset = var->xoffset;
1398 info->var.yoffset = var->yoffset;
1399 }
1400 }
1401 }
1402 drm_modeset_unlock_all(dev: fb_helper->dev);
1403 mutex_unlock(lock: &client->modeset_mutex);
1404
1405 return ret;
1406}
1407
1408/**
1409 * drm_fb_helper_pan_display - implementation for &fb_ops.fb_pan_display
1410 * @var: updated screen information
1411 * @info: fbdev registered by the helper
1412 */
1413int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
1414 struct fb_info *info)
1415{
1416 struct drm_fb_helper *fb_helper = info->par;
1417 struct drm_device *dev = fb_helper->dev;
1418 int ret;
1419
1420 if (oops_in_progress)
1421 return -EBUSY;
1422
1423 mutex_lock(&fb_helper->lock);
1424 if (!drm_master_internal_acquire(dev)) {
1425 ret = -EBUSY;
1426 goto unlock;
1427 }
1428
1429 if (drm_drv_uses_atomic_modeset(dev))
1430 ret = pan_display_atomic(var, info);
1431 else
1432 ret = pan_display_legacy(var, info);
1433
1434 drm_master_internal_release(dev);
1435unlock:
1436 mutex_unlock(lock: &fb_helper->lock);
1437
1438 return ret;
1439}
1440EXPORT_SYMBOL(drm_fb_helper_pan_display);
1441
1442static uint32_t drm_fb_helper_find_format(struct drm_fb_helper *fb_helper, const uint32_t *formats,
1443 size_t format_count, uint32_t bpp, uint32_t depth)
1444{
1445 struct drm_device *dev = fb_helper->dev;
1446 uint32_t format;
1447 size_t i;
1448
1449 /*
1450 * Do not consider YUV or other complicated formats
1451 * for framebuffers. This means only legacy formats
1452 * are supported (fmt->depth is a legacy field), but
1453 * the framebuffer emulation can only deal with such
1454 * formats, specifically RGB/BGA formats.
1455 */
1456 format = drm_mode_legacy_fb_format(bpp, depth);
1457 if (!format)
1458 goto err;
1459
1460 for (i = 0; i < format_count; ++i) {
1461 if (formats[i] == format)
1462 return format;
1463 }
1464
1465err:
1466 /* We found nothing. */
1467 drm_warn(dev, "bpp/depth value of %u/%u not supported\n", bpp, depth);
1468
1469 return DRM_FORMAT_INVALID;
1470}
1471
1472static uint32_t drm_fb_helper_find_color_mode_format(struct drm_fb_helper *fb_helper,
1473 const uint32_t *formats, size_t format_count,
1474 unsigned int color_mode)
1475{
1476 struct drm_device *dev = fb_helper->dev;
1477 uint32_t bpp, depth;
1478
1479 switch (color_mode) {
1480 case 1:
1481 case 2:
1482 case 4:
1483 case 8:
1484 case 16:
1485 case 24:
1486 bpp = depth = color_mode;
1487 break;
1488 case 15:
1489 bpp = 16;
1490 depth = 15;
1491 break;
1492 case 32:
1493 bpp = 32;
1494 depth = 24;
1495 break;
1496 default:
1497 drm_info(dev, "unsupported color mode of %d\n", color_mode);
1498 return DRM_FORMAT_INVALID;
1499 }
1500
1501 return drm_fb_helper_find_format(fb_helper, formats, format_count, bpp, depth);
1502}
1503
1504static int __drm_fb_helper_find_sizes(struct drm_fb_helper *fb_helper,
1505 struct drm_fb_helper_surface_size *sizes)
1506{
1507 struct drm_client_dev *client = &fb_helper->client;
1508 struct drm_device *dev = fb_helper->dev;
1509 int crtc_count = 0;
1510 struct drm_connector_list_iter conn_iter;
1511 struct drm_connector *connector;
1512 struct drm_mode_set *mode_set;
1513 uint32_t surface_format = DRM_FORMAT_INVALID;
1514 const struct drm_format_info *info;
1515
1516 memset(sizes, 0, sizeof(*sizes));
1517 sizes->fb_width = (u32)-1;
1518 sizes->fb_height = (u32)-1;
1519
1520 drm_client_for_each_modeset(mode_set, client) {
1521 struct drm_crtc *crtc = mode_set->crtc;
1522 struct drm_plane *plane = crtc->primary;
1523
1524 drm_dbg_kms(dev, "test CRTC %u primary plane\n", drm_crtc_index(crtc));
1525
1526 drm_connector_list_iter_begin(dev: fb_helper->dev, iter: &conn_iter);
1527 drm_client_for_each_connector_iter(connector, &conn_iter) {
1528 struct drm_cmdline_mode *cmdline_mode = &connector->cmdline_mode;
1529
1530 if (!cmdline_mode->bpp_specified)
1531 continue;
1532
1533 surface_format = drm_fb_helper_find_color_mode_format(fb_helper,
1534 formats: plane->format_types,
1535 format_count: plane->format_count,
1536 color_mode: cmdline_mode->bpp);
1537 if (surface_format != DRM_FORMAT_INVALID)
1538 break; /* found supported format */
1539 }
1540 drm_connector_list_iter_end(iter: &conn_iter);
1541
1542 if (surface_format != DRM_FORMAT_INVALID)
1543 break; /* found supported format */
1544
1545 /* try preferred color mode */
1546 surface_format = drm_fb_helper_find_color_mode_format(fb_helper,
1547 formats: plane->format_types,
1548 format_count: plane->format_count,
1549 color_mode: fb_helper->preferred_bpp);
1550 if (surface_format != DRM_FORMAT_INVALID)
1551 break; /* found supported format */
1552 }
1553
1554 if (surface_format == DRM_FORMAT_INVALID) {
1555 /*
1556 * If none of the given color modes works, fall back
1557 * to XRGB8888. Drivers are expected to provide this
1558 * format for compatibility with legacy applications.
1559 */
1560 drm_warn(dev, "No compatible format found\n");
1561 surface_format = drm_driver_legacy_fb_format(dev, bpp: 32, depth: 24);
1562 }
1563
1564 info = drm_format_info(format: surface_format);
1565 sizes->surface_bpp = drm_format_info_bpp(info, plane: 0);
1566 sizes->surface_depth = info->depth;
1567
1568 /* first up get a count of crtcs now in use and new min/maxes width/heights */
1569 crtc_count = 0;
1570 drm_client_for_each_modeset(mode_set, client) {
1571 struct drm_display_mode *desired_mode;
1572 int x, y, j;
1573 /* in case of tile group, are we the last tile vert or horiz?
1574 * If no tile group you are always the last one both vertically
1575 * and horizontally
1576 */
1577 bool lastv = true, lasth = true;
1578
1579 desired_mode = mode_set->mode;
1580
1581 if (!desired_mode)
1582 continue;
1583
1584 crtc_count++;
1585
1586 x = mode_set->x;
1587 y = mode_set->y;
1588
1589 sizes->surface_width =
1590 max_t(u32, desired_mode->hdisplay + x, sizes->surface_width);
1591 sizes->surface_height =
1592 max_t(u32, desired_mode->vdisplay + y, sizes->surface_height);
1593
1594 for (j = 0; j < mode_set->num_connectors; j++) {
1595 struct drm_connector *connector = mode_set->connectors[j];
1596
1597 if (connector->has_tile &&
1598 desired_mode->hdisplay == connector->tile_h_size &&
1599 desired_mode->vdisplay == connector->tile_v_size) {
1600 lasth = (connector->tile_h_loc == (connector->num_h_tile - 1));
1601 lastv = (connector->tile_v_loc == (connector->num_v_tile - 1));
1602 /* cloning to multiple tiles is just crazy-talk, so: */
1603 break;
1604 }
1605 }
1606
1607 if (lasth)
1608 sizes->fb_width = min_t(u32, desired_mode->hdisplay + x, sizes->fb_width);
1609 if (lastv)
1610 sizes->fb_height = min_t(u32, desired_mode->vdisplay + y, sizes->fb_height);
1611 }
1612
1613 if (crtc_count == 0 || sizes->fb_width == -1 || sizes->fb_height == -1) {
1614 drm_info(dev, "Cannot find any crtc or sizes\n");
1615 return -EAGAIN;
1616 }
1617
1618 return 0;
1619}
1620
1621static int drm_fb_helper_find_sizes(struct drm_fb_helper *fb_helper,
1622 struct drm_fb_helper_surface_size *sizes)
1623{
1624 struct drm_client_dev *client = &fb_helper->client;
1625 struct drm_device *dev = fb_helper->dev;
1626 struct drm_mode_config *config = &dev->mode_config;
1627 int ret;
1628
1629 mutex_lock(&client->modeset_mutex);
1630 ret = __drm_fb_helper_find_sizes(fb_helper, sizes);
1631 mutex_unlock(lock: &client->modeset_mutex);
1632
1633 if (ret)
1634 return ret;
1635
1636 /* Handle our overallocation */
1637 sizes->surface_height *= drm_fbdev_overalloc;
1638 sizes->surface_height /= 100;
1639 if (sizes->surface_height > config->max_height) {
1640 drm_dbg_kms(dev, "Fbdev over-allocation too large; clamping height to %d\n",
1641 config->max_height);
1642 sizes->surface_height = config->max_height;
1643 }
1644
1645 return 0;
1646}
1647
1648/*
1649 * Allocates the backing storage and sets up the fbdev info structure through
1650 * the ->fb_probe callback.
1651 */
1652static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper)
1653{
1654 struct drm_client_dev *client = &fb_helper->client;
1655 struct drm_device *dev = fb_helper->dev;
1656 struct drm_fb_helper_surface_size sizes;
1657 int ret;
1658
1659 ret = drm_fb_helper_find_sizes(fb_helper, sizes: &sizes);
1660 if (ret) {
1661 /* First time: disable all crtc's.. */
1662 if (!fb_helper->deferred_setup)
1663 drm_client_modeset_commit(client);
1664 return ret;
1665 }
1666
1667 /* push down into drivers */
1668 ret = (*fb_helper->funcs->fb_probe)(fb_helper, &sizes);
1669 if (ret < 0)
1670 return ret;
1671
1672 strcpy(p: fb_helper->fb->comm, q: "[fbcon]");
1673
1674 /* Set the fb info for vgaswitcheroo clients. Does nothing otherwise. */
1675 if (dev_is_pci(dev->dev))
1676 vga_switcheroo_client_fb_set(to_pci_dev(dev->dev), info: fb_helper->info);
1677
1678 return 0;
1679}
1680
1681static void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
1682 bool is_color_indexed)
1683{
1684 info->fix.type = FB_TYPE_PACKED_PIXELS;
1685 info->fix.visual = is_color_indexed ? FB_VISUAL_PSEUDOCOLOR
1686 : FB_VISUAL_TRUECOLOR;
1687 info->fix.mmio_start = 0;
1688 info->fix.mmio_len = 0;
1689 info->fix.type_aux = 0;
1690 info->fix.xpanstep = 1; /* doing it in hw */
1691 info->fix.ypanstep = 1; /* doing it in hw */
1692 info->fix.ywrapstep = 0;
1693 info->fix.accel = FB_ACCEL_NONE;
1694
1695 info->fix.line_length = pitch;
1696}
1697
1698static void drm_fb_helper_fill_var(struct fb_info *info,
1699 struct drm_fb_helper *fb_helper,
1700 uint32_t fb_width, uint32_t fb_height)
1701{
1702 struct drm_framebuffer *fb = fb_helper->fb;
1703 const struct drm_format_info *format = fb->format;
1704
1705 switch (format->format) {
1706 case DRM_FORMAT_C1:
1707 case DRM_FORMAT_C2:
1708 case DRM_FORMAT_C4:
1709 /* supported format with sub-byte pixels */
1710 break;
1711
1712 default:
1713 WARN_ON((drm_format_info_block_width(format, 0) > 1) ||
1714 (drm_format_info_block_height(format, 0) > 1));
1715 break;
1716 }
1717
1718 info->pseudo_palette = fb_helper->pseudo_palette;
1719 info->var.xoffset = 0;
1720 info->var.yoffset = 0;
1721 __fill_var(var: &info->var, info, fb);
1722 info->var.activate = FB_ACTIVATE_NOW;
1723
1724 drm_fb_helper_fill_pixel_fmt(var: &info->var, format);
1725
1726 info->var.xres = fb_width;
1727 info->var.yres = fb_height;
1728}
1729
1730/**
1731 * drm_fb_helper_fill_info - initializes fbdev information
1732 * @info: fbdev instance to set up
1733 * @fb_helper: fb helper instance to use as template
1734 * @sizes: describes fbdev size and scanout surface size
1735 *
1736 * Sets up the variable and fixed fbdev metainformation from the given fb helper
1737 * instance and the drm framebuffer allocated in &drm_fb_helper.fb.
1738 *
1739 * Drivers should call this (or their equivalent setup code) from their
1740 * &drm_fb_helper_funcs.fb_probe callback after having allocated the fbdev
1741 * backing storage framebuffer.
1742 */
1743void drm_fb_helper_fill_info(struct fb_info *info,
1744 struct drm_fb_helper *fb_helper,
1745 struct drm_fb_helper_surface_size *sizes)
1746{
1747 struct drm_framebuffer *fb = fb_helper->fb;
1748
1749 drm_fb_helper_fill_fix(info, pitch: fb->pitches[0],
1750 is_color_indexed: fb->format->is_color_indexed);
1751 drm_fb_helper_fill_var(info, fb_helper,
1752 fb_width: sizes->fb_width, fb_height: sizes->fb_height);
1753
1754 info->par = fb_helper;
1755 /*
1756 * The DRM drivers fbdev emulation device name can be confusing if the
1757 * driver name also has a "drm" suffix on it. Leading to names such as
1758 * "simpledrmdrmfb" in /proc/fb. Unfortunately, it's an uAPI and can't
1759 * be changed due user-space tools (e.g: pm-utils) matching against it.
1760 */
1761 snprintf(buf: info->fix.id, size: sizeof(info->fix.id), fmt: "%sdrmfb",
1762 fb_helper->dev->driver->name);
1763
1764}
1765EXPORT_SYMBOL(drm_fb_helper_fill_info);
1766
1767/*
1768 * This is a continuation of drm_setup_crtcs() that sets up anything related
1769 * to the framebuffer. During initialization, drm_setup_crtcs() is called before
1770 * the framebuffer has been allocated (fb_helper->fb and fb_helper->info).
1771 * So, any setup that touches those fields needs to be done here instead of in
1772 * drm_setup_crtcs().
1773 */
1774static void drm_setup_crtcs_fb(struct drm_fb_helper *fb_helper)
1775{
1776 struct drm_client_dev *client = &fb_helper->client;
1777 struct drm_connector_list_iter conn_iter;
1778 struct fb_info *info = fb_helper->info;
1779 unsigned int rotation, sw_rotations = 0;
1780 struct drm_connector *connector;
1781 struct drm_mode_set *modeset;
1782
1783 mutex_lock(&client->modeset_mutex);
1784 drm_client_for_each_modeset(modeset, client) {
1785 if (!modeset->num_connectors)
1786 continue;
1787
1788 modeset->fb = fb_helper->fb;
1789
1790 if (drm_client_rotation(modeset, rotation: &rotation))
1791 /* Rotating in hardware, fbcon should not rotate */
1792 sw_rotations |= DRM_MODE_ROTATE_0;
1793 else
1794 sw_rotations |= rotation;
1795 }
1796 mutex_unlock(lock: &client->modeset_mutex);
1797
1798 drm_connector_list_iter_begin(dev: fb_helper->dev, iter: &conn_iter);
1799 drm_client_for_each_connector_iter(connector, &conn_iter) {
1800
1801 /* use first connected connector for the physical dimensions */
1802 if (connector->status == connector_status_connected) {
1803 info->var.width = connector->display_info.width_mm;
1804 info->var.height = connector->display_info.height_mm;
1805 break;
1806 }
1807 }
1808 drm_connector_list_iter_end(iter: &conn_iter);
1809
1810 switch (sw_rotations) {
1811 case DRM_MODE_ROTATE_0:
1812 info->fbcon_rotate_hint = FB_ROTATE_UR;
1813 break;
1814 case DRM_MODE_ROTATE_90:
1815 info->fbcon_rotate_hint = FB_ROTATE_CCW;
1816 break;
1817 case DRM_MODE_ROTATE_180:
1818 info->fbcon_rotate_hint = FB_ROTATE_UD;
1819 break;
1820 case DRM_MODE_ROTATE_270:
1821 info->fbcon_rotate_hint = FB_ROTATE_CW;
1822 break;
1823 default:
1824 /*
1825 * Multiple bits are set / multiple rotations requested
1826 * fbcon cannot handle separate rotation settings per
1827 * output, so fallback to unrotated.
1828 */
1829 info->fbcon_rotate_hint = FB_ROTATE_UR;
1830 }
1831}
1832
1833/* Note: Drops fb_helper->lock before returning. */
1834static int
1835__drm_fb_helper_initial_config_and_unlock(struct drm_fb_helper *fb_helper)
1836{
1837 struct drm_device *dev = fb_helper->dev;
1838 struct fb_info *info;
1839 unsigned int width, height;
1840 int ret;
1841
1842 width = dev->mode_config.max_width;
1843 height = dev->mode_config.max_height;
1844
1845 drm_client_modeset_probe(client: &fb_helper->client, width, height);
1846 ret = drm_fb_helper_single_fb_probe(fb_helper);
1847 if (ret < 0) {
1848 if (ret == -EAGAIN) {
1849 fb_helper->deferred_setup = true;
1850 ret = 0;
1851 }
1852 mutex_unlock(lock: &fb_helper->lock);
1853
1854 return ret;
1855 }
1856 drm_setup_crtcs_fb(fb_helper);
1857
1858 fb_helper->deferred_setup = false;
1859
1860 info = fb_helper->info;
1861 info->var.pixclock = 0;
1862
1863 if (!drm_leak_fbdev_smem)
1864 info->flags |= FBINFO_HIDE_SMEM_START;
1865
1866 /* Need to drop locks to avoid recursive deadlock in
1867 * register_framebuffer. This is ok because the only thing left to do is
1868 * register the fbdev emulation instance in kernel_fb_helper_list. */
1869 mutex_unlock(lock: &fb_helper->lock);
1870
1871 ret = register_framebuffer(fb_info: info);
1872 if (ret < 0)
1873 return ret;
1874
1875 drm_info(dev, "fb%d: %s frame buffer device\n",
1876 info->node, info->fix.id);
1877
1878 mutex_lock(&kernel_fb_helper_lock);
1879 if (list_empty(head: &kernel_fb_helper_list))
1880 register_sysrq_key(key: 'v', op: &sysrq_drm_fb_helper_restore_op);
1881
1882 list_add(new: &fb_helper->kernel_fb_list, head: &kernel_fb_helper_list);
1883 mutex_unlock(lock: &kernel_fb_helper_lock);
1884
1885 return 0;
1886}
1887
1888/**
1889 * drm_fb_helper_initial_config - setup a sane initial connector configuration
1890 * @fb_helper: fb_helper device struct
1891 *
1892 * Scans the CRTCs and connectors and tries to put together an initial setup.
1893 * At the moment, this is a cloned configuration across all heads with
1894 * a new framebuffer object as the backing store.
1895 *
1896 * Note that this also registers the fbdev and so allows userspace to call into
1897 * the driver through the fbdev interfaces.
1898 *
1899 * This function will call down into the &drm_fb_helper_funcs.fb_probe callback
1900 * to let the driver allocate and initialize the fbdev info structure and the
1901 * drm framebuffer used to back the fbdev. drm_fb_helper_fill_info() is provided
1902 * as a helper to setup simple default values for the fbdev info structure.
1903 *
1904 * HANG DEBUGGING:
1905 *
1906 * When you have fbcon support built-in or already loaded, this function will do
1907 * a full modeset to setup the fbdev console. Due to locking misdesign in the
1908 * VT/fbdev subsystem that entire modeset sequence has to be done while holding
1909 * console_lock. Until console_unlock is called no dmesg lines will be sent out
1910 * to consoles, not even serial console. This means when your driver crashes,
1911 * you will see absolutely nothing else but a system stuck in this function,
1912 * with no further output. Any kind of printk() you place within your own driver
1913 * or in the drm core modeset code will also never show up.
1914 *
1915 * Standard debug practice is to run the fbcon setup without taking the
1916 * console_lock as a hack, to be able to see backtraces and crashes on the
1917 * serial line. This can be done by setting the fb.lockless_register_fb=1 kernel
1918 * cmdline option.
1919 *
1920 * The other option is to just disable fbdev emulation since very likely the
1921 * first modeset from userspace will crash in the same way, and is even easier
1922 * to debug. This can be done by setting the drm_kms_helper.fbdev_emulation=0
1923 * kernel cmdline option.
1924 *
1925 * RETURNS:
1926 * Zero if everything went ok, nonzero otherwise.
1927 */
1928int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper)
1929{
1930 int ret;
1931
1932 if (!drm_fbdev_emulation)
1933 return 0;
1934
1935 mutex_lock(&fb_helper->lock);
1936 ret = __drm_fb_helper_initial_config_and_unlock(fb_helper);
1937
1938 return ret;
1939}
1940EXPORT_SYMBOL(drm_fb_helper_initial_config);
1941
1942/**
1943 * drm_fb_helper_hotplug_event - respond to a hotplug notification by
1944 * probing all the outputs attached to the fb
1945 * @fb_helper: driver-allocated fbdev helper, can be NULL
1946 *
1947 * Scan the connectors attached to the fb_helper and try to put together a
1948 * setup after notification of a change in output configuration.
1949 *
1950 * Called at runtime, takes the mode config locks to be able to check/change the
1951 * modeset configuration. Must be run from process context (which usually means
1952 * either the output polling work or a work item launched from the driver's
1953 * hotplug interrupt).
1954 *
1955 * Note that drivers may call this even before calling
1956 * drm_fb_helper_initial_config but only after drm_fb_helper_init. This allows
1957 * for a race-free fbcon setup and will make sure that the fbdev emulation will
1958 * not miss any hotplug events.
1959 *
1960 * RETURNS:
1961 * 0 on success and a non-zero error code otherwise.
1962 */
1963int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
1964{
1965 int err = 0;
1966
1967 if (!drm_fbdev_emulation || !fb_helper)
1968 return 0;
1969
1970 mutex_lock(&fb_helper->lock);
1971 if (fb_helper->deferred_setup) {
1972 err = __drm_fb_helper_initial_config_and_unlock(fb_helper);
1973 return err;
1974 }
1975
1976 if (!fb_helper->fb || !drm_master_internal_acquire(dev: fb_helper->dev)) {
1977 fb_helper->delayed_hotplug = true;
1978 mutex_unlock(lock: &fb_helper->lock);
1979 return err;
1980 }
1981
1982 drm_master_internal_release(dev: fb_helper->dev);
1983
1984 drm_dbg_kms(fb_helper->dev, "\n");
1985
1986 drm_client_modeset_probe(client: &fb_helper->client, width: fb_helper->fb->width, height: fb_helper->fb->height);
1987 drm_setup_crtcs_fb(fb_helper);
1988 mutex_unlock(lock: &fb_helper->lock);
1989
1990 drm_fb_helper_set_par(fb_helper->info);
1991
1992 return 0;
1993}
1994EXPORT_SYMBOL(drm_fb_helper_hotplug_event);
1995
1996/**
1997 * drm_fb_helper_lastclose - DRM driver lastclose helper for fbdev emulation
1998 * @dev: DRM device
1999 *
2000 * This function can be used as the &drm_driver->lastclose callback for drivers
2001 * that only need to call drm_fb_helper_restore_fbdev_mode_unlocked().
2002 */
2003void drm_fb_helper_lastclose(struct drm_device *dev)
2004{
2005 drm_fb_helper_restore_fbdev_mode_unlocked(dev->fb_helper);
2006}
2007EXPORT_SYMBOL(drm_fb_helper_lastclose);
2008
2009/**
2010 * drm_fb_helper_output_poll_changed - DRM mode config \.output_poll_changed
2011 * helper for fbdev emulation
2012 * @dev: DRM device
2013 *
2014 * This function can be used as the
2015 * &drm_mode_config_funcs.output_poll_changed callback for drivers that only
2016 * need to call drm_fbdev.hotplug_event().
2017 */
2018void drm_fb_helper_output_poll_changed(struct drm_device *dev)
2019{
2020 drm_fb_helper_hotplug_event(dev->fb_helper);
2021}
2022EXPORT_SYMBOL(drm_fb_helper_output_poll_changed);
2023

source code of linux/drivers/gpu/drm/drm_fb_helper.c