2 * Copyright (c) 2006-2009 Red Hat Inc.
3 * Copyright (c) 2006-2008 Intel Corporation
4 * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
6 * DRM framebuffer helper functions
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.
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
27 * Dave Airlie <airlied@linux.ie>
28 * Jesse Barnes <jesse.barnes@intel.com>
30 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
32 #include <linux/console.h>
33 #include <linux/pci.h>
34 #include <linux/sysrq.h>
35 #include <linux/vga_switcheroo.h>
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>
46 #include "drm_internal.h"
48 static bool drm_fbdev_emulation = true;
49 module_param_named(fbdev_emulation, drm_fbdev_emulation, bool, 0600);
50 MODULE_PARM_DESC(fbdev_emulation,
51 "Enable legacy fbdev emulation [default=true]");
53 static int drm_fbdev_overalloc = CONFIG_DRM_FBDEV_OVERALLOC;
54 module_param(drm_fbdev_overalloc, int, 0444);
55 MODULE_PARM_DESC(drm_fbdev_overalloc,
56 "Overallocation of the fbdev buffer (%) [default="
57 __MODULE_STRING(CONFIG_DRM_FBDEV_OVERALLOC) "]");
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 * This is a bad habit essentially kept into closed source opengl driver
64 * that should really be moved into open-source upstream projects instead
65 * of using legacy physical addresses in user space to communicate with
66 * other out-of-tree kernel modules.
68 * This module_param *should* be removed as soon as possible and be
69 * considered as a broken and legacy behaviour from a modern fbdev device.
71 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
72 static bool drm_leak_fbdev_smem;
73 module_param_unsafe(drm_leak_fbdev_smem, bool, 0600);
74 MODULE_PARM_DESC(drm_leak_fbdev_smem,
75 "Allow unsafe leaking fbdev physical smem address [default=false]");
78 static LIST_HEAD(kernel_fb_helper_list);
79 static DEFINE_MUTEX(kernel_fb_helper_lock);
84 * The fb helper functions are useful to provide an fbdev on top of a drm kernel
85 * mode setting driver. They can be used mostly independently from the crtc
86 * helper functions used by many drivers to implement the kernel mode setting
89 * Drivers that support a dumb buffer with a virtual address and mmap support,
90 * should try out the generic fbdev emulation using drm_fbdev_generic_setup().
91 * It will automatically set up deferred I/O if the driver requires a shadow
94 * Existing fbdev implementations should restore the fbdev console by using
95 * drm_fb_helper_lastclose() as their &drm_driver.lastclose callback.
96 * They should also notify the fb helper code from updates to the output
97 * configuration by using drm_fb_helper_output_poll_changed() as their
98 * &drm_mode_config_funcs.output_poll_changed callback. New implementations
99 * of fbdev should be build on top of struct &drm_client_funcs, which handles
100 * this automatically. Setting the old callbacks should be avoided.
102 * For suspend/resume consider using drm_mode_config_helper_suspend() and
103 * drm_mode_config_helper_resume() which takes care of fbdev as well.
105 * All other functions exported by the fb helper library can be used to
106 * implement the fbdev driver interface by the driver.
108 * It is possible, though perhaps somewhat tricky, to implement race-free
109 * hotplug detection using the fbdev helpers. The drm_fb_helper_prepare()
110 * helper must be called first to initialize the minimum required to make
111 * hotplug detection work. Drivers also need to make sure to properly set up
112 * the &drm_mode_config.funcs member. After calling drm_kms_helper_poll_init()
113 * it is safe to enable interrupts and start processing hotplug events. At the
114 * same time, drivers should initialize all modeset objects such as CRTCs,
115 * encoders and connectors. To finish up the fbdev helper initialization, the
116 * drm_fb_helper_init() function is called. To probe for all attached displays
117 * and set up an initial configuration using the detected hardware, drivers
118 * should call drm_fb_helper_initial_config().
120 * If &drm_framebuffer_funcs.dirty is set, the
121 * drm_fb_helper_{cfb,sys}_{write,fillrect,copyarea,imageblit} functions will
122 * accumulate changes and schedule &drm_fb_helper.dirty_work to run right
123 * away. This worker then calls the dirty() function ensuring that it will
124 * always run in process context since the fb_*() function could be running in
125 * atomic context. If drm_fb_helper_deferred_io() is used as the deferred_io
126 * callback it will also schedule dirty_work with the damage collected from the
129 * Deferred I/O is not compatible with SHMEM. Such drivers should request an
130 * fbdev shadow buffer and call drm_fbdev_generic_setup() instead.
133 static void drm_fb_helper_restore_lut_atomic(struct drm_crtc *crtc)
135 uint16_t *r_base, *g_base, *b_base;
137 if (crtc->funcs->gamma_set == NULL)
140 r_base = crtc->gamma_store;
141 g_base = r_base + crtc->gamma_size;
142 b_base = g_base + crtc->gamma_size;
144 crtc->funcs->gamma_set(crtc, r_base, g_base, b_base,
145 crtc->gamma_size, NULL);
149 * drm_fb_helper_debug_enter - implementation for &fb_ops.fb_debug_enter
150 * @info: fbdev registered by the helper
152 int drm_fb_helper_debug_enter(struct fb_info *info)
154 struct drm_fb_helper *helper = info->par;
155 const struct drm_crtc_helper_funcs *funcs;
156 struct drm_mode_set *mode_set;
158 list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
159 mutex_lock(&helper->client.modeset_mutex);
160 drm_client_for_each_modeset(mode_set, &helper->client) {
161 if (!mode_set->crtc->enabled)
164 funcs = mode_set->crtc->helper_private;
165 if (funcs->mode_set_base_atomic == NULL)
168 if (drm_drv_uses_atomic_modeset(mode_set->crtc->dev))
171 funcs->mode_set_base_atomic(mode_set->crtc,
175 ENTER_ATOMIC_MODE_SET);
177 mutex_unlock(&helper->client.modeset_mutex);
182 EXPORT_SYMBOL(drm_fb_helper_debug_enter);
185 * drm_fb_helper_debug_leave - implementation for &fb_ops.fb_debug_leave
186 * @info: fbdev registered by the helper
188 int drm_fb_helper_debug_leave(struct fb_info *info)
190 struct drm_fb_helper *helper = info->par;
191 struct drm_client_dev *client = &helper->client;
192 struct drm_device *dev = helper->dev;
193 struct drm_crtc *crtc;
194 const struct drm_crtc_helper_funcs *funcs;
195 struct drm_mode_set *mode_set;
196 struct drm_framebuffer *fb;
198 mutex_lock(&client->modeset_mutex);
199 drm_client_for_each_modeset(mode_set, client) {
200 crtc = mode_set->crtc;
201 if (drm_drv_uses_atomic_modeset(crtc->dev))
204 funcs = crtc->helper_private;
205 fb = crtc->primary->fb;
211 drm_err(dev, "no fb to restore?\n");
215 if (funcs->mode_set_base_atomic == NULL)
218 drm_fb_helper_restore_lut_atomic(mode_set->crtc);
219 funcs->mode_set_base_atomic(mode_set->crtc, fb, crtc->x,
220 crtc->y, LEAVE_ATOMIC_MODE_SET);
222 mutex_unlock(&client->modeset_mutex);
226 EXPORT_SYMBOL(drm_fb_helper_debug_leave);
229 __drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper,
235 if (!drm_fbdev_emulation || !fb_helper)
238 if (READ_ONCE(fb_helper->deferred_setup))
241 mutex_lock(&fb_helper->lock);
244 * Yes this is the _locked version which expects the master lock
245 * to be held. But for forced restores we're intentionally
246 * racing here, see drm_fb_helper_set_par().
248 ret = drm_client_modeset_commit_locked(&fb_helper->client);
250 ret = drm_client_modeset_commit(&fb_helper->client);
253 do_delayed = fb_helper->delayed_hotplug;
255 fb_helper->delayed_hotplug = false;
256 mutex_unlock(&fb_helper->lock);
259 drm_fb_helper_hotplug_event(fb_helper);
265 * drm_fb_helper_restore_fbdev_mode_unlocked - restore fbdev configuration
266 * @fb_helper: driver-allocated fbdev helper, can be NULL
268 * This should be called from driver's drm &drm_driver.lastclose callback
269 * when implementing an fbcon on top of kms using this helper. This ensures that
270 * the user isn't greeted with a black screen when e.g. X dies.
273 * Zero if everything went ok, negative error code otherwise.
275 int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
277 return __drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper, false);
279 EXPORT_SYMBOL(drm_fb_helper_restore_fbdev_mode_unlocked);
281 #ifdef CONFIG_MAGIC_SYSRQ
282 /* emergency restore, don't bother with error reporting */
283 static void drm_fb_helper_restore_work_fn(struct work_struct *ignored)
285 struct drm_fb_helper *helper;
287 mutex_lock(&kernel_fb_helper_lock);
288 list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
289 struct drm_device *dev = helper->dev;
291 if (dev->switch_power_state == DRM_SWITCH_POWER_OFF)
294 mutex_lock(&helper->lock);
295 drm_client_modeset_commit_locked(&helper->client);
296 mutex_unlock(&helper->lock);
298 mutex_unlock(&kernel_fb_helper_lock);
301 static DECLARE_WORK(drm_fb_helper_restore_work, drm_fb_helper_restore_work_fn);
303 static void drm_fb_helper_sysrq(int dummy1)
305 schedule_work(&drm_fb_helper_restore_work);
308 static const struct sysrq_key_op sysrq_drm_fb_helper_restore_op = {
309 .handler = drm_fb_helper_sysrq,
310 .help_msg = "force-fb(v)",
311 .action_msg = "Restore framebuffer console",
314 static const struct sysrq_key_op sysrq_drm_fb_helper_restore_op = { };
317 static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode)
319 struct drm_fb_helper *fb_helper = info->par;
321 mutex_lock(&fb_helper->lock);
322 drm_client_modeset_dpms(&fb_helper->client, dpms_mode);
323 mutex_unlock(&fb_helper->lock);
327 * drm_fb_helper_blank - implementation for &fb_ops.fb_blank
328 * @blank: desired blanking state
329 * @info: fbdev registered by the helper
331 int drm_fb_helper_blank(int blank, struct fb_info *info)
333 if (oops_in_progress)
337 /* Display: On; HSync: On, VSync: On */
338 case FB_BLANK_UNBLANK:
339 drm_fb_helper_dpms(info, DRM_MODE_DPMS_ON);
341 /* Display: Off; HSync: On, VSync: On */
342 case FB_BLANK_NORMAL:
343 drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
345 /* Display: Off; HSync: Off, VSync: On */
346 case FB_BLANK_HSYNC_SUSPEND:
347 drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
349 /* Display: Off; HSync: On, VSync: Off */
350 case FB_BLANK_VSYNC_SUSPEND:
351 drm_fb_helper_dpms(info, DRM_MODE_DPMS_SUSPEND);
353 /* Display: Off; HSync: Off, VSync: Off */
354 case FB_BLANK_POWERDOWN:
355 drm_fb_helper_dpms(info, DRM_MODE_DPMS_OFF);
360 EXPORT_SYMBOL(drm_fb_helper_blank);
362 static void drm_fb_helper_resume_worker(struct work_struct *work)
364 struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper,
368 fb_set_suspend(helper->info, 0);
372 static void drm_fb_helper_fb_dirty(struct drm_fb_helper *helper)
374 struct drm_device *dev = helper->dev;
375 struct drm_clip_rect *clip = &helper->damage_clip;
376 struct drm_clip_rect clip_copy;
380 if (drm_WARN_ON_ONCE(dev, !helper->funcs->fb_dirty))
383 spin_lock_irqsave(&helper->damage_lock, flags);
385 clip->x1 = clip->y1 = ~0;
386 clip->x2 = clip->y2 = 0;
387 spin_unlock_irqrestore(&helper->damage_lock, flags);
389 ret = helper->funcs->fb_dirty(helper, &clip_copy);
397 * Restore damage clip rectangle on errors. The next run
398 * of the damage worker will perform the update.
400 spin_lock_irqsave(&helper->damage_lock, flags);
401 clip->x1 = min_t(u32, clip->x1, clip_copy.x1);
402 clip->y1 = min_t(u32, clip->y1, clip_copy.y1);
403 clip->x2 = max_t(u32, clip->x2, clip_copy.x2);
404 clip->y2 = max_t(u32, clip->y2, clip_copy.y2);
405 spin_unlock_irqrestore(&helper->damage_lock, flags);
408 static void drm_fb_helper_damage_work(struct work_struct *work)
410 struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper, damage_work);
412 drm_fb_helper_fb_dirty(helper);
416 * drm_fb_helper_prepare - setup a drm_fb_helper structure
418 * @helper: driver-allocated fbdev helper structure to set up
419 * @funcs: pointer to structure of functions associate with this helper
421 * Sets up the bare minimum to make the framebuffer helper usable. This is
422 * useful to implement race-free initialization of the polling helpers.
424 void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
425 const struct drm_fb_helper_funcs *funcs)
427 INIT_LIST_HEAD(&helper->kernel_fb_list);
428 spin_lock_init(&helper->damage_lock);
429 INIT_WORK(&helper->resume_work, drm_fb_helper_resume_worker);
430 INIT_WORK(&helper->damage_work, drm_fb_helper_damage_work);
431 helper->damage_clip.x1 = helper->damage_clip.y1 = ~0;
432 mutex_init(&helper->lock);
433 helper->funcs = funcs;
436 EXPORT_SYMBOL(drm_fb_helper_prepare);
439 * drm_fb_helper_init - initialize a &struct drm_fb_helper
441 * @fb_helper: driver-allocated fbdev helper structure to initialize
443 * This allocates the structures for the fbdev helper with the given limits.
444 * Note that this won't yet touch the hardware (through the driver interfaces)
445 * nor register the fbdev. This is only done in drm_fb_helper_initial_config()
446 * to allow driver writes more control over the exact init sequence.
448 * Drivers must call drm_fb_helper_prepare() before calling this function.
451 * Zero if everything went ok, nonzero otherwise.
453 int drm_fb_helper_init(struct drm_device *dev,
454 struct drm_fb_helper *fb_helper)
459 * If this is not the generic fbdev client, initialize a drm_client
460 * without callbacks so we can use the modesets.
462 if (!fb_helper->client.funcs) {
463 ret = drm_client_init(dev, &fb_helper->client, "drm_fb_helper", NULL);
468 dev->fb_helper = fb_helper;
472 EXPORT_SYMBOL(drm_fb_helper_init);
475 * drm_fb_helper_alloc_info - allocate fb_info and some of its members
476 * @fb_helper: driver-allocated fbdev helper
478 * A helper to alloc fb_info and the members cmap and apertures. Called
479 * by the driver within the fb_probe fb_helper callback function. Drivers do not
480 * need to release the allocated fb_info structure themselves, this is
481 * automatically done when calling drm_fb_helper_fini().
484 * fb_info pointer if things went okay, pointer containing error code
487 struct fb_info *drm_fb_helper_alloc_info(struct drm_fb_helper *fb_helper)
489 struct device *dev = fb_helper->dev->dev;
490 struct fb_info *info;
493 info = framebuffer_alloc(0, dev);
495 return ERR_PTR(-ENOMEM);
497 ret = fb_alloc_cmap(&info->cmap, 256, 0);
502 * TODO: We really should be smarter here and alloc an aperture
503 * for each IORESOURCE_MEM resource helper->dev->dev has and also
504 * init the ranges of the appertures based on the resources.
505 * Note some drivers currently count on there being only 1 empty
506 * aperture and fill this themselves, these will need to be dealt
507 * with somehow when fixing this.
509 info->apertures = alloc_apertures(1);
510 if (!info->apertures) {
515 fb_helper->info = info;
516 info->skip_vt_switch = true;
521 fb_dealloc_cmap(&info->cmap);
523 framebuffer_release(info);
526 EXPORT_SYMBOL(drm_fb_helper_alloc_info);
529 * drm_fb_helper_unregister_info - unregister fb_info framebuffer device
530 * @fb_helper: driver-allocated fbdev helper, can be NULL
532 * A wrapper around unregister_framebuffer, to release the fb_info
533 * framebuffer device. This must be called before releasing all resources for
534 * @fb_helper by calling drm_fb_helper_fini().
536 void drm_fb_helper_unregister_info(struct drm_fb_helper *fb_helper)
538 if (fb_helper && fb_helper->info)
539 unregister_framebuffer(fb_helper->info);
541 EXPORT_SYMBOL(drm_fb_helper_unregister_info);
544 * drm_fb_helper_fini - finialize a &struct drm_fb_helper
545 * @fb_helper: driver-allocated fbdev helper, can be NULL
547 * This cleans up all remaining resources associated with @fb_helper.
549 void drm_fb_helper_fini(struct drm_fb_helper *fb_helper)
551 struct fb_info *info;
556 fb_helper->dev->fb_helper = NULL;
558 if (!drm_fbdev_emulation)
561 cancel_work_sync(&fb_helper->resume_work);
562 cancel_work_sync(&fb_helper->damage_work);
564 info = fb_helper->info;
567 fb_dealloc_cmap(&info->cmap);
568 framebuffer_release(info);
570 fb_helper->info = NULL;
572 mutex_lock(&kernel_fb_helper_lock);
573 if (!list_empty(&fb_helper->kernel_fb_list)) {
574 list_del(&fb_helper->kernel_fb_list);
575 if (list_empty(&kernel_fb_helper_list))
576 unregister_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
578 mutex_unlock(&kernel_fb_helper_lock);
580 mutex_destroy(&fb_helper->lock);
582 if (!fb_helper->client.funcs)
583 drm_client_release(&fb_helper->client);
585 EXPORT_SYMBOL(drm_fb_helper_fini);
587 static void drm_fb_helper_add_damage_clip(struct drm_fb_helper *helper, u32 x, u32 y,
588 u32 width, u32 height)
590 struct drm_clip_rect *clip = &helper->damage_clip;
593 spin_lock_irqsave(&helper->damage_lock, flags);
594 clip->x1 = min_t(u32, clip->x1, x);
595 clip->y1 = min_t(u32, clip->y1, y);
596 clip->x2 = max_t(u32, clip->x2, x + width);
597 clip->y2 = max_t(u32, clip->y2, y + height);
598 spin_unlock_irqrestore(&helper->damage_lock, flags);
601 static void drm_fb_helper_damage(struct drm_fb_helper *helper, u32 x, u32 y,
602 u32 width, u32 height)
604 drm_fb_helper_add_damage_clip(helper, x, y, width, height);
606 schedule_work(&helper->damage_work);
610 * Convert memory region into area of scanlines and pixels per
611 * scanline. The parameters off and len must not reach beyond
612 * the end of the framebuffer.
614 static void drm_fb_helper_memory_range_to_clip(struct fb_info *info, off_t off, size_t len,
615 struct drm_rect *clip)
617 off_t end = off + len;
619 u32 y1 = off / info->fix.line_length;
620 u32 x2 = info->var.xres;
621 u32 y2 = DIV_ROUND_UP(end, info->fix.line_length);
623 if ((y2 - y1) == 1) {
625 * We've only written to a single scanline. Try to reduce
626 * the number of horizontal pixels that need an update.
628 off_t bit_off = (off % info->fix.line_length) * 8;
629 off_t bit_end = (end % info->fix.line_length) * 8;
631 x1 = bit_off / info->var.bits_per_pixel;
632 x2 = DIV_ROUND_UP(bit_end, info->var.bits_per_pixel);
635 drm_rect_init(clip, x1, y1, x2 - x1, y2 - y1);
639 * drm_fb_helper_deferred_io() - fbdev deferred_io callback function
640 * @info: fb_info struct pointer
641 * @pagereflist: list of mmap framebuffer pages that have to be flushed
643 * This function is used as the &fb_deferred_io.deferred_io
644 * callback function for flushing the fbdev mmap writes.
646 void drm_fb_helper_deferred_io(struct fb_info *info, struct list_head *pagereflist)
648 struct drm_fb_helper *helper = info->par;
649 unsigned long start, end, min_off, max_off;
650 struct fb_deferred_io_pageref *pageref;
651 struct drm_rect damage_area;
655 list_for_each_entry(pageref, pagereflist, list) {
656 start = pageref->offset;
657 end = start + PAGE_SIZE;
658 min_off = min(min_off, start);
659 max_off = max(max_off, end);
663 * As we can only track pages, we might reach beyond the end
664 * of the screen and account for non-existing scanlines. Hence,
665 * keep the covered memory area within the screen buffer.
667 max_off = min(max_off, info->screen_size);
669 if (min_off < max_off) {
670 drm_fb_helper_memory_range_to_clip(info, min_off, max_off - min_off, &damage_area);
671 drm_fb_helper_damage(helper, damage_area.x1, damage_area.y1,
672 drm_rect_width(&damage_area),
673 drm_rect_height(&damage_area));
676 EXPORT_SYMBOL(drm_fb_helper_deferred_io);
678 typedef ssize_t (*drm_fb_helper_read_screen)(struct fb_info *info, char __user *buf,
679 size_t count, loff_t pos);
681 static ssize_t __drm_fb_helper_read(struct fb_info *info, char __user *buf, size_t count,
682 loff_t *ppos, drm_fb_helper_read_screen read_screen)
688 if (info->screen_size)
689 total_size = info->screen_size;
691 total_size = info->fix.smem_len;
693 if (pos >= total_size)
695 if (count >= total_size)
697 if (total_size - count < pos)
698 count = total_size - pos;
700 if (info->fbops->fb_sync)
701 info->fbops->fb_sync(info);
703 ret = read_screen(info, buf, count, pos);
710 typedef ssize_t (*drm_fb_helper_write_screen)(struct fb_info *info, const char __user *buf,
711 size_t count, loff_t pos);
713 static ssize_t __drm_fb_helper_write(struct fb_info *info, const char __user *buf, size_t count,
714 loff_t *ppos, drm_fb_helper_write_screen write_screen)
721 if (info->screen_size)
722 total_size = info->screen_size;
724 total_size = info->fix.smem_len;
726 if (pos > total_size)
728 if (count > total_size) {
732 if (total_size - count < pos) {
735 count = total_size - pos;
738 if (info->fbops->fb_sync)
739 info->fbops->fb_sync(info);
742 * Copy to framebuffer even if we already logged an error. Emulates
743 * the behavior of the original fbdev implementation.
745 ret = write_screen(info, buf, count, pos);
747 return ret; /* return last error, if any */
749 return err; /* return previous error, if any */
756 static ssize_t drm_fb_helper_read_screen_buffer(struct fb_info *info, char __user *buf,
757 size_t count, loff_t pos)
759 const char *src = info->screen_buffer + pos;
761 if (copy_to_user(buf, src, count))
768 * drm_fb_helper_sys_read - Implements struct &fb_ops.fb_read for system memory
769 * @info: fb_info struct pointer
770 * @buf: userspace buffer to read from framebuffer memory
771 * @count: number of bytes to read from framebuffer memory
772 * @ppos: read offset within framebuffer memory
775 * The number of bytes read on success, or an error code otherwise.
777 ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
778 size_t count, loff_t *ppos)
780 return __drm_fb_helper_read(info, buf, count, ppos, drm_fb_helper_read_screen_buffer);
782 EXPORT_SYMBOL(drm_fb_helper_sys_read);
784 static ssize_t drm_fb_helper_write_screen_buffer(struct fb_info *info, const char __user *buf,
785 size_t count, loff_t pos)
787 char *dst = info->screen_buffer + pos;
789 if (copy_from_user(dst, buf, count))
796 * drm_fb_helper_sys_write - Implements struct &fb_ops.fb_write for system memory
797 * @info: fb_info struct pointer
798 * @buf: userspace buffer to write to framebuffer memory
799 * @count: number of bytes to write to framebuffer memory
800 * @ppos: write offset within framebuffer memory
803 * The number of bytes written on success, or an error code otherwise.
805 ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
806 size_t count, loff_t *ppos)
808 struct drm_fb_helper *helper = info->par;
811 struct drm_rect damage_area;
813 ret = __drm_fb_helper_write(info, buf, count, ppos, drm_fb_helper_write_screen_buffer);
817 if (helper->funcs->fb_dirty) {
818 drm_fb_helper_memory_range_to_clip(info, pos, ret, &damage_area);
819 drm_fb_helper_damage(helper, damage_area.x1, damage_area.y1,
820 drm_rect_width(&damage_area),
821 drm_rect_height(&damage_area));
826 EXPORT_SYMBOL(drm_fb_helper_sys_write);
829 * drm_fb_helper_sys_fillrect - wrapper around sys_fillrect
830 * @info: fbdev registered by the helper
831 * @rect: info about rectangle to fill
833 * A wrapper around sys_fillrect implemented by fbdev core
835 void drm_fb_helper_sys_fillrect(struct fb_info *info,
836 const struct fb_fillrect *rect)
838 struct drm_fb_helper *helper = info->par;
840 sys_fillrect(info, rect);
842 if (helper->funcs->fb_dirty)
843 drm_fb_helper_damage(helper, rect->dx, rect->dy, rect->width, rect->height);
845 EXPORT_SYMBOL(drm_fb_helper_sys_fillrect);
848 * drm_fb_helper_sys_copyarea - wrapper around sys_copyarea
849 * @info: fbdev registered by the helper
850 * @area: info about area to copy
852 * A wrapper around sys_copyarea implemented by fbdev core
854 void drm_fb_helper_sys_copyarea(struct fb_info *info,
855 const struct fb_copyarea *area)
857 struct drm_fb_helper *helper = info->par;
859 sys_copyarea(info, area);
861 if (helper->funcs->fb_dirty)
862 drm_fb_helper_damage(helper, area->dx, area->dy, area->width, area->height);
864 EXPORT_SYMBOL(drm_fb_helper_sys_copyarea);
867 * drm_fb_helper_sys_imageblit - wrapper around sys_imageblit
868 * @info: fbdev registered by the helper
869 * @image: info about image to blit
871 * A wrapper around sys_imageblit implemented by fbdev core
873 void drm_fb_helper_sys_imageblit(struct fb_info *info,
874 const struct fb_image *image)
876 struct drm_fb_helper *helper = info->par;
878 sys_imageblit(info, image);
880 if (helper->funcs->fb_dirty)
881 drm_fb_helper_damage(helper, image->dx, image->dy, image->width, image->height);
883 EXPORT_SYMBOL(drm_fb_helper_sys_imageblit);
885 static ssize_t fb_read_screen_base(struct fb_info *info, char __user *buf, size_t count,
888 const char __iomem *src = info->screen_base + pos;
889 size_t alloc_size = min_t(size_t, count, PAGE_SIZE);
894 tmp = kmalloc(alloc_size, GFP_KERNEL);
899 size_t c = min_t(size_t, count, alloc_size);
901 memcpy_fromio(tmp, src, c);
902 if (copy_to_user(buf, tmp, c)) {
915 return ret ? ret : err;
919 * drm_fb_helper_cfb_read - Implements struct &fb_ops.fb_read for I/O memory
920 * @info: fb_info struct pointer
921 * @buf: userspace buffer to read from framebuffer memory
922 * @count: number of bytes to read from framebuffer memory
923 * @ppos: read offset within framebuffer memory
926 * The number of bytes read on success, or an error code otherwise.
928 ssize_t drm_fb_helper_cfb_read(struct fb_info *info, char __user *buf,
929 size_t count, loff_t *ppos)
931 return __drm_fb_helper_read(info, buf, count, ppos, fb_read_screen_base);
933 EXPORT_SYMBOL(drm_fb_helper_cfb_read);
935 static ssize_t fb_write_screen_base(struct fb_info *info, const char __user *buf, size_t count,
938 char __iomem *dst = info->screen_base + pos;
939 size_t alloc_size = min_t(size_t, count, PAGE_SIZE);
944 tmp = kmalloc(alloc_size, GFP_KERNEL);
949 size_t c = min_t(size_t, count, alloc_size);
951 if (copy_from_user(tmp, buf, c)) {
955 memcpy_toio(dst, tmp, c);
965 return ret ? ret : err;
969 * drm_fb_helper_cfb_write - Implements struct &fb_ops.fb_write for I/O memory
970 * @info: fb_info struct pointer
971 * @buf: userspace buffer to write to framebuffer memory
972 * @count: number of bytes to write to framebuffer memory
973 * @ppos: write offset within framebuffer memory
976 * The number of bytes written on success, or an error code otherwise.
978 ssize_t drm_fb_helper_cfb_write(struct fb_info *info, const char __user *buf,
979 size_t count, loff_t *ppos)
981 struct drm_fb_helper *helper = info->par;
984 struct drm_rect damage_area;
986 ret = __drm_fb_helper_write(info, buf, count, ppos, fb_write_screen_base);
990 if (helper->funcs->fb_dirty) {
991 drm_fb_helper_memory_range_to_clip(info, pos, ret, &damage_area);
992 drm_fb_helper_damage(helper, damage_area.x1, damage_area.y1,
993 drm_rect_width(&damage_area),
994 drm_rect_height(&damage_area));
999 EXPORT_SYMBOL(drm_fb_helper_cfb_write);
1002 * drm_fb_helper_cfb_fillrect - wrapper around cfb_fillrect
1003 * @info: fbdev registered by the helper
1004 * @rect: info about rectangle to fill
1006 * A wrapper around cfb_fillrect implemented by fbdev core
1008 void drm_fb_helper_cfb_fillrect(struct fb_info *info,
1009 const struct fb_fillrect *rect)
1011 struct drm_fb_helper *helper = info->par;
1013 cfb_fillrect(info, rect);
1015 if (helper->funcs->fb_dirty)
1016 drm_fb_helper_damage(helper, rect->dx, rect->dy, rect->width, rect->height);
1018 EXPORT_SYMBOL(drm_fb_helper_cfb_fillrect);
1021 * drm_fb_helper_cfb_copyarea - wrapper around cfb_copyarea
1022 * @info: fbdev registered by the helper
1023 * @area: info about area to copy
1025 * A wrapper around cfb_copyarea implemented by fbdev core
1027 void drm_fb_helper_cfb_copyarea(struct fb_info *info,
1028 const struct fb_copyarea *area)
1030 struct drm_fb_helper *helper = info->par;
1032 cfb_copyarea(info, area);
1034 if (helper->funcs->fb_dirty)
1035 drm_fb_helper_damage(helper, area->dx, area->dy, area->width, area->height);
1037 EXPORT_SYMBOL(drm_fb_helper_cfb_copyarea);
1040 * drm_fb_helper_cfb_imageblit - wrapper around cfb_imageblit
1041 * @info: fbdev registered by the helper
1042 * @image: info about image to blit
1044 * A wrapper around cfb_imageblit implemented by fbdev core
1046 void drm_fb_helper_cfb_imageblit(struct fb_info *info,
1047 const struct fb_image *image)
1049 struct drm_fb_helper *helper = info->par;
1051 cfb_imageblit(info, image);
1053 if (helper->funcs->fb_dirty)
1054 drm_fb_helper_damage(helper, image->dx, image->dy, image->width, image->height);
1056 EXPORT_SYMBOL(drm_fb_helper_cfb_imageblit);
1059 * drm_fb_helper_set_suspend - wrapper around fb_set_suspend
1060 * @fb_helper: driver-allocated fbdev helper, can be NULL
1061 * @suspend: whether to suspend or resume
1063 * A wrapper around fb_set_suspend implemented by fbdev core.
1064 * Use drm_fb_helper_set_suspend_unlocked() if you don't need to take
1067 void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend)
1069 if (fb_helper && fb_helper->info)
1070 fb_set_suspend(fb_helper->info, suspend);
1072 EXPORT_SYMBOL(drm_fb_helper_set_suspend);
1075 * drm_fb_helper_set_suspend_unlocked - wrapper around fb_set_suspend that also
1076 * takes the console lock
1077 * @fb_helper: driver-allocated fbdev helper, can be NULL
1078 * @suspend: whether to suspend or resume
1080 * A wrapper around fb_set_suspend() that takes the console lock. If the lock
1081 * isn't available on resume, a worker is tasked with waiting for the lock
1082 * to become available. The console lock can be pretty contented on resume
1083 * due to all the printk activity.
1085 * This function can be called multiple times with the same state since
1086 * &fb_info.state is checked to see if fbdev is running or not before locking.
1088 * Use drm_fb_helper_set_suspend() if you need to take the lock yourself.
1090 void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
1093 if (!fb_helper || !fb_helper->info)
1096 /* make sure there's no pending/ongoing resume */
1097 flush_work(&fb_helper->resume_work);
1100 if (fb_helper->info->state != FBINFO_STATE_RUNNING)
1106 if (fb_helper->info->state == FBINFO_STATE_RUNNING)
1109 if (!console_trylock()) {
1110 schedule_work(&fb_helper->resume_work);
1115 fb_set_suspend(fb_helper->info, suspend);
1118 EXPORT_SYMBOL(drm_fb_helper_set_suspend_unlocked);
1120 static int setcmap_pseudo_palette(struct fb_cmap *cmap, struct fb_info *info)
1122 u32 *palette = (u32 *)info->pseudo_palette;
1125 if (cmap->start + cmap->len > 16)
1128 for (i = 0; i < cmap->len; ++i) {
1129 u16 red = cmap->red[i];
1130 u16 green = cmap->green[i];
1131 u16 blue = cmap->blue[i];
1134 red >>= 16 - info->var.red.length;
1135 green >>= 16 - info->var.green.length;
1136 blue >>= 16 - info->var.blue.length;
1137 value = (red << info->var.red.offset) |
1138 (green << info->var.green.offset) |
1139 (blue << info->var.blue.offset);
1140 if (info->var.transp.length > 0) {
1141 u32 mask = (1 << info->var.transp.length) - 1;
1143 mask <<= info->var.transp.offset;
1146 palette[cmap->start + i] = value;
1152 static int setcmap_legacy(struct fb_cmap *cmap, struct fb_info *info)
1154 struct drm_fb_helper *fb_helper = info->par;
1155 struct drm_mode_set *modeset;
1156 struct drm_crtc *crtc;
1160 drm_modeset_lock_all(fb_helper->dev);
1161 drm_client_for_each_modeset(modeset, &fb_helper->client) {
1162 crtc = modeset->crtc;
1163 if (!crtc->funcs->gamma_set || !crtc->gamma_size) {
1168 if (cmap->start + cmap->len > crtc->gamma_size) {
1173 r = crtc->gamma_store;
1174 g = r + crtc->gamma_size;
1175 b = g + crtc->gamma_size;
1177 memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
1178 memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
1179 memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
1181 ret = crtc->funcs->gamma_set(crtc, r, g, b,
1182 crtc->gamma_size, NULL);
1187 drm_modeset_unlock_all(fb_helper->dev);
1192 static struct drm_property_blob *setcmap_new_gamma_lut(struct drm_crtc *crtc,
1193 struct fb_cmap *cmap)
1195 struct drm_device *dev = crtc->dev;
1196 struct drm_property_blob *gamma_lut;
1197 struct drm_color_lut *lut;
1198 int size = crtc->gamma_size;
1201 if (!size || cmap->start + cmap->len > size)
1202 return ERR_PTR(-EINVAL);
1204 gamma_lut = drm_property_create_blob(dev, sizeof(*lut) * size, NULL);
1205 if (IS_ERR(gamma_lut))
1208 lut = gamma_lut->data;
1209 if (cmap->start || cmap->len != size) {
1210 u16 *r = crtc->gamma_store;
1211 u16 *g = r + crtc->gamma_size;
1212 u16 *b = g + crtc->gamma_size;
1214 for (i = 0; i < cmap->start; i++) {
1216 lut[i].green = g[i];
1219 for (i = cmap->start + cmap->len; i < size; i++) {
1221 lut[i].green = g[i];
1226 for (i = 0; i < cmap->len; i++) {
1227 lut[cmap->start + i].red = cmap->red[i];
1228 lut[cmap->start + i].green = cmap->green[i];
1229 lut[cmap->start + i].blue = cmap->blue[i];
1235 static int setcmap_atomic(struct fb_cmap *cmap, struct fb_info *info)
1237 struct drm_fb_helper *fb_helper = info->par;
1238 struct drm_device *dev = fb_helper->dev;
1239 struct drm_property_blob *gamma_lut = NULL;
1240 struct drm_modeset_acquire_ctx ctx;
1241 struct drm_crtc_state *crtc_state;
1242 struct drm_atomic_state *state;
1243 struct drm_mode_set *modeset;
1244 struct drm_crtc *crtc;
1249 drm_modeset_acquire_init(&ctx, 0);
1251 state = drm_atomic_state_alloc(dev);
1257 state->acquire_ctx = &ctx;
1259 drm_client_for_each_modeset(modeset, &fb_helper->client) {
1260 crtc = modeset->crtc;
1263 gamma_lut = setcmap_new_gamma_lut(crtc, cmap);
1264 if (IS_ERR(gamma_lut)) {
1265 ret = PTR_ERR(gamma_lut);
1270 crtc_state = drm_atomic_get_crtc_state(state, crtc);
1271 if (IS_ERR(crtc_state)) {
1272 ret = PTR_ERR(crtc_state);
1277 * FIXME: This always uses gamma_lut. Some HW have only
1278 * degamma_lut, in which case we should reset gamma_lut and set
1279 * degamma_lut. See drm_crtc_legacy_gamma_set().
1281 replaced = drm_property_replace_blob(&crtc_state->degamma_lut,
1283 replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
1284 replaced |= drm_property_replace_blob(&crtc_state->gamma_lut,
1286 crtc_state->color_mgmt_changed |= replaced;
1289 ret = drm_atomic_commit(state);
1293 drm_client_for_each_modeset(modeset, &fb_helper->client) {
1294 crtc = modeset->crtc;
1296 r = crtc->gamma_store;
1297 g = r + crtc->gamma_size;
1298 b = g + crtc->gamma_size;
1300 memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
1301 memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
1302 memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
1306 if (ret == -EDEADLK)
1309 drm_property_blob_put(gamma_lut);
1310 drm_atomic_state_put(state);
1312 drm_modeset_drop_locks(&ctx);
1313 drm_modeset_acquire_fini(&ctx);
1318 drm_atomic_state_clear(state);
1319 drm_modeset_backoff(&ctx);
1324 * drm_fb_helper_setcmap - implementation for &fb_ops.fb_setcmap
1325 * @cmap: cmap to set
1326 * @info: fbdev registered by the helper
1328 int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
1330 struct drm_fb_helper *fb_helper = info->par;
1331 struct drm_device *dev = fb_helper->dev;
1334 if (oops_in_progress)
1337 mutex_lock(&fb_helper->lock);
1339 if (!drm_master_internal_acquire(dev)) {
1344 mutex_lock(&fb_helper->client.modeset_mutex);
1345 if (info->fix.visual == FB_VISUAL_TRUECOLOR)
1346 ret = setcmap_pseudo_palette(cmap, info);
1347 else if (drm_drv_uses_atomic_modeset(fb_helper->dev))
1348 ret = setcmap_atomic(cmap, info);
1350 ret = setcmap_legacy(cmap, info);
1351 mutex_unlock(&fb_helper->client.modeset_mutex);
1353 drm_master_internal_release(dev);
1355 mutex_unlock(&fb_helper->lock);
1359 EXPORT_SYMBOL(drm_fb_helper_setcmap);
1362 * drm_fb_helper_ioctl - legacy ioctl implementation
1363 * @info: fbdev registered by the helper
1364 * @cmd: ioctl command
1365 * @arg: ioctl argument
1367 * A helper to implement the standard fbdev ioctl. Only
1368 * FBIO_WAITFORVSYNC is implemented for now.
1370 int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
1373 struct drm_fb_helper *fb_helper = info->par;
1374 struct drm_device *dev = fb_helper->dev;
1375 struct drm_crtc *crtc;
1378 mutex_lock(&fb_helper->lock);
1379 if (!drm_master_internal_acquire(dev)) {
1385 case FBIO_WAITFORVSYNC:
1387 * Only consider the first CRTC.
1389 * This ioctl is supposed to take the CRTC number as
1390 * an argument, but in fbdev times, what that number
1391 * was supposed to be was quite unclear, different
1392 * drivers were passing that argument differently
1393 * (some by reference, some by value), and most of the
1394 * userspace applications were just hardcoding 0 as an
1397 * The first CRTC should be the integrated panel on
1398 * most drivers, so this is the best choice we can
1399 * make. If we're not smart enough here, one should
1400 * just consider switch the userspace to KMS.
1402 crtc = fb_helper->client.modesets[0].crtc;
1405 * Only wait for a vblank event if the CRTC is
1406 * enabled, otherwise just don't do anythintg,
1407 * not even report an error.
1409 ret = drm_crtc_vblank_get(crtc);
1411 drm_crtc_wait_one_vblank(crtc);
1412 drm_crtc_vblank_put(crtc);
1421 drm_master_internal_release(dev);
1423 mutex_unlock(&fb_helper->lock);
1426 EXPORT_SYMBOL(drm_fb_helper_ioctl);
1428 static bool drm_fb_pixel_format_equal(const struct fb_var_screeninfo *var_1,
1429 const struct fb_var_screeninfo *var_2)
1431 return var_1->bits_per_pixel == var_2->bits_per_pixel &&
1432 var_1->grayscale == var_2->grayscale &&
1433 var_1->red.offset == var_2->red.offset &&
1434 var_1->red.length == var_2->red.length &&
1435 var_1->red.msb_right == var_2->red.msb_right &&
1436 var_1->green.offset == var_2->green.offset &&
1437 var_1->green.length == var_2->green.length &&
1438 var_1->green.msb_right == var_2->green.msb_right &&
1439 var_1->blue.offset == var_2->blue.offset &&
1440 var_1->blue.length == var_2->blue.length &&
1441 var_1->blue.msb_right == var_2->blue.msb_right &&
1442 var_1->transp.offset == var_2->transp.offset &&
1443 var_1->transp.length == var_2->transp.length &&
1444 var_1->transp.msb_right == var_2->transp.msb_right;
1447 static void drm_fb_helper_fill_pixel_fmt(struct fb_var_screeninfo *var,
1448 const struct drm_format_info *format)
1450 u8 depth = format->depth;
1452 if (format->is_color_indexed) {
1453 var->red.offset = 0;
1454 var->green.offset = 0;
1455 var->blue.offset = 0;
1456 var->red.length = depth;
1457 var->green.length = depth;
1458 var->blue.length = depth;
1459 var->transp.offset = 0;
1460 var->transp.length = 0;
1466 var->red.offset = 10;
1467 var->green.offset = 5;
1468 var->blue.offset = 0;
1469 var->red.length = 5;
1470 var->green.length = 5;
1471 var->blue.length = 5;
1472 var->transp.offset = 15;
1473 var->transp.length = 1;
1476 var->red.offset = 11;
1477 var->green.offset = 5;
1478 var->blue.offset = 0;
1479 var->red.length = 5;
1480 var->green.length = 6;
1481 var->blue.length = 5;
1482 var->transp.offset = 0;
1485 var->red.offset = 16;
1486 var->green.offset = 8;
1487 var->blue.offset = 0;
1488 var->red.length = 8;
1489 var->green.length = 8;
1490 var->blue.length = 8;
1491 var->transp.offset = 0;
1492 var->transp.length = 0;
1495 var->red.offset = 16;
1496 var->green.offset = 8;
1497 var->blue.offset = 0;
1498 var->red.length = 8;
1499 var->green.length = 8;
1500 var->blue.length = 8;
1501 var->transp.offset = 24;
1502 var->transp.length = 8;
1510 * drm_fb_helper_check_var - implementation for &fb_ops.fb_check_var
1511 * @var: screeninfo to check
1512 * @info: fbdev registered by the helper
1514 int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
1515 struct fb_info *info)
1517 struct drm_fb_helper *fb_helper = info->par;
1518 struct drm_framebuffer *fb = fb_helper->fb;
1519 const struct drm_format_info *format = fb->format;
1520 struct drm_device *dev = fb_helper->dev;
1523 if (in_dbg_master())
1526 if (var->pixclock != 0) {
1527 drm_dbg_kms(dev, "fbdev emulation doesn't support changing the pixel clock, value of pixclock is ignored\n");
1531 switch (format->format) {
1535 /* supported format with sub-byte pixels */
1539 if ((drm_format_info_block_width(format, 0) > 1) ||
1540 (drm_format_info_block_height(format, 0) > 1))
1546 * Changes struct fb_var_screeninfo are currently not pushed back
1547 * to KMS, hence fail if different settings are requested.
1549 bpp = drm_format_info_bpp(format, 0);
1550 if (var->bits_per_pixel > bpp ||
1551 var->xres > fb->width || var->yres > fb->height ||
1552 var->xres_virtual > fb->width || var->yres_virtual > fb->height) {
1553 drm_dbg_kms(dev, "fb requested width/height/bpp can't fit in current fb "
1554 "request %dx%d-%d (virtual %dx%d) > %dx%d-%d\n",
1555 var->xres, var->yres, var->bits_per_pixel,
1556 var->xres_virtual, var->yres_virtual,
1557 fb->width, fb->height, bpp);
1562 * Workaround for SDL 1.2, which is known to be setting all pixel format
1563 * fields values to zero in some cases. We treat this situation as a
1564 * kind of "use some reasonable autodetected values".
1566 if (!var->red.offset && !var->green.offset &&
1567 !var->blue.offset && !var->transp.offset &&
1568 !var->red.length && !var->green.length &&
1569 !var->blue.length && !var->transp.length &&
1570 !var->red.msb_right && !var->green.msb_right &&
1571 !var->blue.msb_right && !var->transp.msb_right) {
1572 drm_fb_helper_fill_pixel_fmt(var, format);
1576 * Likewise, bits_per_pixel should be rounded up to a supported value.
1578 var->bits_per_pixel = bpp;
1581 * drm fbdev emulation doesn't support changing the pixel format at all,
1582 * so reject all pixel format changing requests.
1584 if (!drm_fb_pixel_format_equal(var, &info->var)) {
1585 drm_dbg_kms(dev, "fbdev emulation doesn't support changing the pixel format\n");
1591 EXPORT_SYMBOL(drm_fb_helper_check_var);
1594 * drm_fb_helper_set_par - implementation for &fb_ops.fb_set_par
1595 * @info: fbdev registered by the helper
1597 * This will let fbcon do the mode init and is called at initialization time by
1598 * the fbdev core when registering the driver, and later on through the hotplug
1601 int drm_fb_helper_set_par(struct fb_info *info)
1603 struct drm_fb_helper *fb_helper = info->par;
1604 struct fb_var_screeninfo *var = &info->var;
1607 if (oops_in_progress)
1610 if (var->pixclock != 0) {
1611 drm_err(fb_helper->dev, "PIXEL CLOCK SET\n");
1616 * Normally we want to make sure that a kms master takes precedence over
1617 * fbdev, to avoid fbdev flickering and occasionally stealing the
1618 * display status. But Xorg first sets the vt back to text mode using
1619 * the KDSET IOCTL with KD_TEXT, and only after that drops the master
1620 * status when exiting.
1622 * In the past this was caught by drm_fb_helper_lastclose(), but on
1623 * modern systems where logind always keeps a drm fd open to orchestrate
1624 * the vt switching, this doesn't work.
1626 * To not break the userspace ABI we have this special case here, which
1627 * is only used for the above case. Everything else uses the normal
1628 * commit function, which ensures that we never steal the display from
1629 * an active drm master.
1631 force = var->activate & FB_ACTIVATE_KD_TEXT;
1633 __drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper, force);
1637 EXPORT_SYMBOL(drm_fb_helper_set_par);
1639 static void pan_set(struct drm_fb_helper *fb_helper, int x, int y)
1641 struct drm_mode_set *mode_set;
1643 mutex_lock(&fb_helper->client.modeset_mutex);
1644 drm_client_for_each_modeset(mode_set, &fb_helper->client) {
1648 mutex_unlock(&fb_helper->client.modeset_mutex);
1651 static int pan_display_atomic(struct fb_var_screeninfo *var,
1652 struct fb_info *info)
1654 struct drm_fb_helper *fb_helper = info->par;
1657 pan_set(fb_helper, var->xoffset, var->yoffset);
1659 ret = drm_client_modeset_commit_locked(&fb_helper->client);
1661 info->var.xoffset = var->xoffset;
1662 info->var.yoffset = var->yoffset;
1664 pan_set(fb_helper, info->var.xoffset, info->var.yoffset);
1669 static int pan_display_legacy(struct fb_var_screeninfo *var,
1670 struct fb_info *info)
1672 struct drm_fb_helper *fb_helper = info->par;
1673 struct drm_client_dev *client = &fb_helper->client;
1674 struct drm_mode_set *modeset;
1677 mutex_lock(&client->modeset_mutex);
1678 drm_modeset_lock_all(fb_helper->dev);
1679 drm_client_for_each_modeset(modeset, client) {
1680 modeset->x = var->xoffset;
1681 modeset->y = var->yoffset;
1683 if (modeset->num_connectors) {
1684 ret = drm_mode_set_config_internal(modeset);
1686 info->var.xoffset = var->xoffset;
1687 info->var.yoffset = var->yoffset;
1691 drm_modeset_unlock_all(fb_helper->dev);
1692 mutex_unlock(&client->modeset_mutex);
1698 * drm_fb_helper_pan_display - implementation for &fb_ops.fb_pan_display
1699 * @var: updated screen information
1700 * @info: fbdev registered by the helper
1702 int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
1703 struct fb_info *info)
1705 struct drm_fb_helper *fb_helper = info->par;
1706 struct drm_device *dev = fb_helper->dev;
1709 if (oops_in_progress)
1712 mutex_lock(&fb_helper->lock);
1713 if (!drm_master_internal_acquire(dev)) {
1718 if (drm_drv_uses_atomic_modeset(dev))
1719 ret = pan_display_atomic(var, info);
1721 ret = pan_display_legacy(var, info);
1723 drm_master_internal_release(dev);
1725 mutex_unlock(&fb_helper->lock);
1729 EXPORT_SYMBOL(drm_fb_helper_pan_display);
1732 * Allocates the backing storage and sets up the fbdev info structure through
1733 * the ->fb_probe callback.
1735 static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
1738 struct drm_client_dev *client = &fb_helper->client;
1739 struct drm_device *dev = fb_helper->dev;
1740 struct drm_mode_config *config = &dev->mode_config;
1743 struct drm_connector_list_iter conn_iter;
1744 struct drm_fb_helper_surface_size sizes;
1745 struct drm_connector *connector;
1746 struct drm_mode_set *mode_set;
1749 memset(&sizes, 0, sizeof(struct drm_fb_helper_surface_size));
1750 sizes.surface_depth = 24;
1751 sizes.surface_bpp = 32;
1752 sizes.fb_width = (u32)-1;
1753 sizes.fb_height = (u32)-1;
1756 * If driver picks 8 or 16 by default use that for both depth/bpp
1759 if (preferred_bpp != sizes.surface_bpp)
1760 sizes.surface_depth = sizes.surface_bpp = preferred_bpp;
1762 drm_connector_list_iter_begin(fb_helper->dev, &conn_iter);
1763 drm_client_for_each_connector_iter(connector, &conn_iter) {
1764 struct drm_cmdline_mode *cmdline_mode;
1766 cmdline_mode = &connector->cmdline_mode;
1768 if (cmdline_mode->bpp_specified) {
1769 switch (cmdline_mode->bpp) {
1771 sizes.surface_depth = sizes.surface_bpp = 8;
1774 sizes.surface_depth = 15;
1775 sizes.surface_bpp = 16;
1778 sizes.surface_depth = sizes.surface_bpp = 16;
1781 sizes.surface_depth = sizes.surface_bpp = 24;
1784 sizes.surface_depth = 24;
1785 sizes.surface_bpp = 32;
1791 drm_connector_list_iter_end(&conn_iter);
1794 * If we run into a situation where, for example, the primary plane
1795 * supports RGBA5551 (16 bpp, depth 15) but not RGB565 (16 bpp, depth
1796 * 16) we need to scale down the depth of the sizes we request.
1798 mutex_lock(&client->modeset_mutex);
1799 drm_client_for_each_modeset(mode_set, client) {
1800 struct drm_crtc *crtc = mode_set->crtc;
1801 struct drm_plane *plane = crtc->primary;
1804 drm_dbg_kms(dev, "test CRTC %u primary plane\n", drm_crtc_index(crtc));
1806 for (j = 0; j < plane->format_count; j++) {
1807 const struct drm_format_info *fmt;
1809 fmt = drm_format_info(plane->format_types[j]);
1812 * Do not consider YUV or other complicated formats
1813 * for framebuffers. This means only legacy formats
1814 * are supported (fmt->depth is a legacy field) but
1815 * the framebuffer emulation can only deal with such
1816 * formats, specifically RGB/BGA formats.
1818 if (fmt->depth == 0)
1821 /* We found a perfect fit, great */
1822 if (fmt->depth == sizes.surface_depth) {
1823 best_depth = fmt->depth;
1827 /* Skip depths above what we're looking for */
1828 if (fmt->depth > sizes.surface_depth)
1831 /* Best depth found so far */
1832 if (fmt->depth > best_depth)
1833 best_depth = fmt->depth;
1836 if (sizes.surface_depth != best_depth && best_depth) {
1837 drm_info(dev, "requested bpp %d, scaled depth down to %d",
1838 sizes.surface_bpp, best_depth);
1839 sizes.surface_depth = best_depth;
1842 /* first up get a count of crtcs now in use and new min/maxes width/heights */
1844 drm_client_for_each_modeset(mode_set, client) {
1845 struct drm_display_mode *desired_mode;
1847 /* in case of tile group, are we the last tile vert or horiz?
1848 * If no tile group you are always the last one both vertically
1851 bool lastv = true, lasth = true;
1853 desired_mode = mode_set->mode;
1863 sizes.surface_width = max_t(u32, desired_mode->hdisplay + x, sizes.surface_width);
1864 sizes.surface_height = max_t(u32, desired_mode->vdisplay + y, sizes.surface_height);
1866 for (j = 0; j < mode_set->num_connectors; j++) {
1867 struct drm_connector *connector = mode_set->connectors[j];
1869 if (connector->has_tile &&
1870 desired_mode->hdisplay == connector->tile_h_size &&
1871 desired_mode->vdisplay == connector->tile_v_size) {
1872 lasth = (connector->tile_h_loc == (connector->num_h_tile - 1));
1873 lastv = (connector->tile_v_loc == (connector->num_v_tile - 1));
1874 /* cloning to multiple tiles is just crazy-talk, so: */
1880 sizes.fb_width = min_t(u32, desired_mode->hdisplay + x, sizes.fb_width);
1882 sizes.fb_height = min_t(u32, desired_mode->vdisplay + y, sizes.fb_height);
1884 mutex_unlock(&client->modeset_mutex);
1886 if (crtc_count == 0 || sizes.fb_width == -1 || sizes.fb_height == -1) {
1887 drm_info(dev, "Cannot find any crtc or sizes\n");
1889 /* First time: disable all crtc's.. */
1890 if (!fb_helper->deferred_setup)
1891 drm_client_modeset_commit(client);
1895 /* Handle our overallocation */
1896 sizes.surface_height *= drm_fbdev_overalloc;
1897 sizes.surface_height /= 100;
1898 if (sizes.surface_height > config->max_height) {
1899 drm_dbg_kms(dev, "Fbdev over-allocation too large; clamping height to %d\n",
1900 config->max_height);
1901 sizes.surface_height = config->max_height;
1904 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
1905 fb_helper->hint_leak_smem_start = drm_leak_fbdev_smem;
1908 /* push down into drivers */
1909 ret = (*fb_helper->funcs->fb_probe)(fb_helper, &sizes);
1913 strcpy(fb_helper->fb->comm, "[fbcon]");
1915 /* Set the fb info for vgaswitcheroo clients. Does nothing otherwise. */
1916 if (dev_is_pci(dev->dev))
1917 vga_switcheroo_client_fb_set(to_pci_dev(dev->dev), fb_helper->info);
1922 static void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
1923 bool is_color_indexed)
1925 info->fix.type = FB_TYPE_PACKED_PIXELS;
1926 info->fix.visual = is_color_indexed ? FB_VISUAL_PSEUDOCOLOR
1927 : FB_VISUAL_TRUECOLOR;
1928 info->fix.mmio_start = 0;
1929 info->fix.mmio_len = 0;
1930 info->fix.type_aux = 0;
1931 info->fix.xpanstep = 1; /* doing it in hw */
1932 info->fix.ypanstep = 1; /* doing it in hw */
1933 info->fix.ywrapstep = 0;
1934 info->fix.accel = FB_ACCEL_NONE;
1936 info->fix.line_length = pitch;
1939 static void drm_fb_helper_fill_var(struct fb_info *info,
1940 struct drm_fb_helper *fb_helper,
1941 uint32_t fb_width, uint32_t fb_height)
1943 struct drm_framebuffer *fb = fb_helper->fb;
1944 const struct drm_format_info *format = fb->format;
1946 switch (format->format) {
1950 /* supported format with sub-byte pixels */
1954 WARN_ON((drm_format_info_block_width(format, 0) > 1) ||
1955 (drm_format_info_block_height(format, 0) > 1));
1959 info->pseudo_palette = fb_helper->pseudo_palette;
1960 info->var.xres_virtual = fb->width;
1961 info->var.yres_virtual = fb->height;
1962 info->var.bits_per_pixel = drm_format_info_bpp(format, 0);
1963 info->var.accel_flags = FB_ACCELF_TEXT;
1964 info->var.xoffset = 0;
1965 info->var.yoffset = 0;
1966 info->var.activate = FB_ACTIVATE_NOW;
1968 drm_fb_helper_fill_pixel_fmt(&info->var, format);
1970 info->var.xres = fb_width;
1971 info->var.yres = fb_height;
1975 * drm_fb_helper_fill_info - initializes fbdev information
1976 * @info: fbdev instance to set up
1977 * @fb_helper: fb helper instance to use as template
1978 * @sizes: describes fbdev size and scanout surface size
1980 * Sets up the variable and fixed fbdev metainformation from the given fb helper
1981 * instance and the drm framebuffer allocated in &drm_fb_helper.fb.
1983 * Drivers should call this (or their equivalent setup code) from their
1984 * &drm_fb_helper_funcs.fb_probe callback after having allocated the fbdev
1985 * backing storage framebuffer.
1987 void drm_fb_helper_fill_info(struct fb_info *info,
1988 struct drm_fb_helper *fb_helper,
1989 struct drm_fb_helper_surface_size *sizes)
1991 struct drm_framebuffer *fb = fb_helper->fb;
1993 drm_fb_helper_fill_fix(info, fb->pitches[0],
1994 fb->format->is_color_indexed);
1995 drm_fb_helper_fill_var(info, fb_helper,
1996 sizes->fb_width, sizes->fb_height);
1998 info->par = fb_helper;
2000 * The DRM drivers fbdev emulation device name can be confusing if the
2001 * driver name also has a "drm" suffix on it. Leading to names such as
2002 * "simpledrmdrmfb" in /proc/fb. Unfortunately, it's an uAPI and can't
2003 * be changed due user-space tools (e.g: pm-utils) matching against it.
2005 snprintf(info->fix.id, sizeof(info->fix.id), "%sdrmfb",
2006 fb_helper->dev->driver->name);
2009 EXPORT_SYMBOL(drm_fb_helper_fill_info);
2012 * This is a continuation of drm_setup_crtcs() that sets up anything related
2013 * to the framebuffer. During initialization, drm_setup_crtcs() is called before
2014 * the framebuffer has been allocated (fb_helper->fb and fb_helper->info).
2015 * So, any setup that touches those fields needs to be done here instead of in
2016 * drm_setup_crtcs().
2018 static void drm_setup_crtcs_fb(struct drm_fb_helper *fb_helper)
2020 struct drm_client_dev *client = &fb_helper->client;
2021 struct drm_connector_list_iter conn_iter;
2022 struct fb_info *info = fb_helper->info;
2023 unsigned int rotation, sw_rotations = 0;
2024 struct drm_connector *connector;
2025 struct drm_mode_set *modeset;
2027 mutex_lock(&client->modeset_mutex);
2028 drm_client_for_each_modeset(modeset, client) {
2029 if (!modeset->num_connectors)
2032 modeset->fb = fb_helper->fb;
2034 if (drm_client_rotation(modeset, &rotation))
2035 /* Rotating in hardware, fbcon should not rotate */
2036 sw_rotations |= DRM_MODE_ROTATE_0;
2038 sw_rotations |= rotation;
2040 mutex_unlock(&client->modeset_mutex);
2042 drm_connector_list_iter_begin(fb_helper->dev, &conn_iter);
2043 drm_client_for_each_connector_iter(connector, &conn_iter) {
2045 /* use first connected connector for the physical dimensions */
2046 if (connector->status == connector_status_connected) {
2047 info->var.width = connector->display_info.width_mm;
2048 info->var.height = connector->display_info.height_mm;
2052 drm_connector_list_iter_end(&conn_iter);
2054 switch (sw_rotations) {
2055 case DRM_MODE_ROTATE_0:
2056 info->fbcon_rotate_hint = FB_ROTATE_UR;
2058 case DRM_MODE_ROTATE_90:
2059 info->fbcon_rotate_hint = FB_ROTATE_CCW;
2061 case DRM_MODE_ROTATE_180:
2062 info->fbcon_rotate_hint = FB_ROTATE_UD;
2064 case DRM_MODE_ROTATE_270:
2065 info->fbcon_rotate_hint = FB_ROTATE_CW;
2069 * Multiple bits are set / multiple rotations requested
2070 * fbcon cannot handle separate rotation settings per
2071 * output, so fallback to unrotated.
2073 info->fbcon_rotate_hint = FB_ROTATE_UR;
2077 /* Note: Drops fb_helper->lock before returning. */
2079 __drm_fb_helper_initial_config_and_unlock(struct drm_fb_helper *fb_helper,
2082 struct drm_device *dev = fb_helper->dev;
2083 struct fb_info *info;
2084 unsigned int width, height;
2087 width = dev->mode_config.max_width;
2088 height = dev->mode_config.max_height;
2090 drm_client_modeset_probe(&fb_helper->client, width, height);
2091 ret = drm_fb_helper_single_fb_probe(fb_helper, bpp_sel);
2093 if (ret == -EAGAIN) {
2094 fb_helper->preferred_bpp = bpp_sel;
2095 fb_helper->deferred_setup = true;
2098 mutex_unlock(&fb_helper->lock);
2102 drm_setup_crtcs_fb(fb_helper);
2104 fb_helper->deferred_setup = false;
2106 info = fb_helper->info;
2107 info->var.pixclock = 0;
2108 /* Shamelessly allow physical address leaking to userspace */
2109 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
2110 if (!fb_helper->hint_leak_smem_start)
2112 /* don't leak any physical addresses to userspace */
2113 info->flags |= FBINFO_HIDE_SMEM_START;
2115 /* Need to drop locks to avoid recursive deadlock in
2116 * register_framebuffer. This is ok because the only thing left to do is
2117 * register the fbdev emulation instance in kernel_fb_helper_list. */
2118 mutex_unlock(&fb_helper->lock);
2120 ret = register_framebuffer(info);
2124 drm_info(dev, "fb%d: %s frame buffer device\n",
2125 info->node, info->fix.id);
2127 mutex_lock(&kernel_fb_helper_lock);
2128 if (list_empty(&kernel_fb_helper_list))
2129 register_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
2131 list_add(&fb_helper->kernel_fb_list, &kernel_fb_helper_list);
2132 mutex_unlock(&kernel_fb_helper_lock);
2138 * drm_fb_helper_initial_config - setup a sane initial connector configuration
2139 * @fb_helper: fb_helper device struct
2140 * @bpp_sel: bpp value to use for the framebuffer configuration
2142 * Scans the CRTCs and connectors and tries to put together an initial setup.
2143 * At the moment, this is a cloned configuration across all heads with
2144 * a new framebuffer object as the backing store.
2146 * Note that this also registers the fbdev and so allows userspace to call into
2147 * the driver through the fbdev interfaces.
2149 * This function will call down into the &drm_fb_helper_funcs.fb_probe callback
2150 * to let the driver allocate and initialize the fbdev info structure and the
2151 * drm framebuffer used to back the fbdev. drm_fb_helper_fill_info() is provided
2152 * as a helper to setup simple default values for the fbdev info structure.
2156 * When you have fbcon support built-in or already loaded, this function will do
2157 * a full modeset to setup the fbdev console. Due to locking misdesign in the
2158 * VT/fbdev subsystem that entire modeset sequence has to be done while holding
2159 * console_lock. Until console_unlock is called no dmesg lines will be sent out
2160 * to consoles, not even serial console. This means when your driver crashes,
2161 * you will see absolutely nothing else but a system stuck in this function,
2162 * with no further output. Any kind of printk() you place within your own driver
2163 * or in the drm core modeset code will also never show up.
2165 * Standard debug practice is to run the fbcon setup without taking the
2166 * console_lock as a hack, to be able to see backtraces and crashes on the
2167 * serial line. This can be done by setting the fb.lockless_register_fb=1 kernel
2170 * The other option is to just disable fbdev emulation since very likely the
2171 * first modeset from userspace will crash in the same way, and is even easier
2172 * to debug. This can be done by setting the drm_kms_helper.fbdev_emulation=0
2173 * kernel cmdline option.
2176 * Zero if everything went ok, nonzero otherwise.
2178 int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel)
2182 if (!drm_fbdev_emulation)
2185 mutex_lock(&fb_helper->lock);
2186 ret = __drm_fb_helper_initial_config_and_unlock(fb_helper, bpp_sel);
2190 EXPORT_SYMBOL(drm_fb_helper_initial_config);
2193 * drm_fb_helper_hotplug_event - respond to a hotplug notification by
2194 * probing all the outputs attached to the fb
2195 * @fb_helper: driver-allocated fbdev helper, can be NULL
2197 * Scan the connectors attached to the fb_helper and try to put together a
2198 * setup after notification of a change in output configuration.
2200 * Called at runtime, takes the mode config locks to be able to check/change the
2201 * modeset configuration. Must be run from process context (which usually means
2202 * either the output polling work or a work item launched from the driver's
2203 * hotplug interrupt).
2205 * Note that drivers may call this even before calling
2206 * drm_fb_helper_initial_config but only after drm_fb_helper_init. This allows
2207 * for a race-free fbcon setup and will make sure that the fbdev emulation will
2208 * not miss any hotplug events.
2211 * 0 on success and a non-zero error code otherwise.
2213 int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
2217 if (!drm_fbdev_emulation || !fb_helper)
2220 mutex_lock(&fb_helper->lock);
2221 if (fb_helper->deferred_setup) {
2222 err = __drm_fb_helper_initial_config_and_unlock(fb_helper,
2223 fb_helper->preferred_bpp);
2227 if (!fb_helper->fb || !drm_master_internal_acquire(fb_helper->dev)) {
2228 fb_helper->delayed_hotplug = true;
2229 mutex_unlock(&fb_helper->lock);
2233 drm_master_internal_release(fb_helper->dev);
2235 drm_dbg_kms(fb_helper->dev, "\n");
2237 drm_client_modeset_probe(&fb_helper->client, fb_helper->fb->width, fb_helper->fb->height);
2238 drm_setup_crtcs_fb(fb_helper);
2239 mutex_unlock(&fb_helper->lock);
2241 drm_fb_helper_set_par(fb_helper->info);
2245 EXPORT_SYMBOL(drm_fb_helper_hotplug_event);
2248 * drm_fb_helper_lastclose - DRM driver lastclose helper for fbdev emulation
2251 * This function can be used as the &drm_driver->lastclose callback for drivers
2252 * that only need to call drm_fb_helper_restore_fbdev_mode_unlocked().
2254 void drm_fb_helper_lastclose(struct drm_device *dev)
2256 drm_fb_helper_restore_fbdev_mode_unlocked(dev->fb_helper);
2258 EXPORT_SYMBOL(drm_fb_helper_lastclose);
2261 * drm_fb_helper_output_poll_changed - DRM mode config \.output_poll_changed
2262 * helper for fbdev emulation
2265 * This function can be used as the
2266 * &drm_mode_config_funcs.output_poll_changed callback for drivers that only
2267 * need to call drm_fbdev.hotplug_event().
2269 void drm_fb_helper_output_poll_changed(struct drm_device *dev)
2271 drm_fb_helper_hotplug_event(dev->fb_helper);
2273 EXPORT_SYMBOL(drm_fb_helper_output_poll_changed);