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/sysrq.h>
35 #include <drm/drm_atomic.h>
36 #include <drm/drm_drv.h>
37 #include <drm/drm_fb_helper.h>
38 #include <drm/drm_fourcc.h>
39 #include <drm/drm_framebuffer.h>
40 #include <drm/drm_modeset_helper_vtables.h>
41 #include <drm/drm_print.h>
42 #include <drm/drm_vblank.h>
44 #include "drm_internal.h"
46 static bool drm_fbdev_emulation = true;
47 module_param_named(fbdev_emulation, drm_fbdev_emulation, bool, 0600);
48 MODULE_PARM_DESC(fbdev_emulation,
49 "Enable legacy fbdev emulation [default=true]");
51 static int drm_fbdev_overalloc = CONFIG_DRM_FBDEV_OVERALLOC;
52 module_param(drm_fbdev_overalloc, int, 0444);
53 MODULE_PARM_DESC(drm_fbdev_overalloc,
54 "Overallocation of the fbdev buffer (%) [default="
55 __MODULE_STRING(CONFIG_DRM_FBDEV_OVERALLOC) "]");
58 * In order to keep user-space compatibility, we want in certain use-cases
59 * to keep leaking the fbdev physical address to the user-space program
60 * handling the fbdev buffer.
61 * This is a bad habit essentially kept into closed source opengl driver
62 * that should really be moved into open-source upstream projects instead
63 * of using legacy physical addresses in user space to communicate with
64 * other out-of-tree kernel modules.
66 * This module_param *should* be removed as soon as possible and be
67 * considered as a broken and legacy behaviour from a modern fbdev device.
69 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
70 static bool drm_leak_fbdev_smem;
71 module_param_unsafe(drm_leak_fbdev_smem, bool, 0600);
72 MODULE_PARM_DESC(drm_leak_fbdev_smem,
73 "Allow unsafe leaking fbdev physical smem address [default=false]");
76 static LIST_HEAD(kernel_fb_helper_list);
77 static DEFINE_MUTEX(kernel_fb_helper_lock);
82 * The fb helper functions are useful to provide an fbdev on top of a drm kernel
83 * mode setting driver. They can be used mostly independently from the crtc
84 * helper functions used by many drivers to implement the kernel mode setting
87 * Drivers that support a dumb buffer with a virtual address and mmap support,
88 * should try out the generic fbdev emulation using drm_fbdev_generic_setup().
89 * It will automatically set up deferred I/O if the driver requires a shadow
92 * Existing fbdev implementations should restore the fbdev console by using
93 * drm_fb_helper_lastclose() as their &drm_driver.lastclose callback.
94 * They should also notify the fb helper code from updates to the output
95 * configuration by using drm_fb_helper_output_poll_changed() as their
96 * &drm_mode_config_funcs.output_poll_changed callback. New implementations
97 * of fbdev should be build on top of struct &drm_client_funcs, which handles
98 * this automatically. Setting the old callbacks should be avoided.
100 * For suspend/resume consider using drm_mode_config_helper_suspend() and
101 * drm_mode_config_helper_resume() which takes care of fbdev as well.
103 * All other functions exported by the fb helper library can be used to
104 * implement the fbdev driver interface by the driver.
106 * It is possible, though perhaps somewhat tricky, to implement race-free
107 * hotplug detection using the fbdev helpers. The drm_fb_helper_prepare()
108 * helper must be called first to initialize the minimum required to make
109 * hotplug detection work. Drivers also need to make sure to properly set up
110 * the &drm_mode_config.funcs member. After calling drm_kms_helper_poll_init()
111 * it is safe to enable interrupts and start processing hotplug events. At the
112 * same time, drivers should initialize all modeset objects such as CRTCs,
113 * encoders and connectors. To finish up the fbdev helper initialization, the
114 * drm_fb_helper_init() function is called. To probe for all attached displays
115 * and set up an initial configuration using the detected hardware, drivers
116 * should call drm_fb_helper_initial_config().
118 * If &drm_framebuffer_funcs.dirty is set, the
119 * drm_fb_helper_{cfb,sys}_{write,fillrect,copyarea,imageblit} functions will
120 * accumulate changes and schedule &drm_fb_helper.dirty_work to run right
121 * away. This worker then calls the dirty() function ensuring that it will
122 * always run in process context since the fb_*() function could be running in
123 * atomic context. If drm_fb_helper_deferred_io() is used as the deferred_io
124 * callback it will also schedule dirty_work with the damage collected from the
127 * Deferred I/O is not compatible with SHMEM. Such drivers should request an
128 * fbdev shadow buffer and call drm_fbdev_generic_setup() instead.
131 static void drm_fb_helper_restore_lut_atomic(struct drm_crtc *crtc)
133 uint16_t *r_base, *g_base, *b_base;
135 if (crtc->funcs->gamma_set == NULL)
138 r_base = crtc->gamma_store;
139 g_base = r_base + crtc->gamma_size;
140 b_base = g_base + crtc->gamma_size;
142 crtc->funcs->gamma_set(crtc, r_base, g_base, b_base,
143 crtc->gamma_size, NULL);
147 * drm_fb_helper_debug_enter - implementation for &fb_ops.fb_debug_enter
148 * @info: fbdev registered by the helper
150 int drm_fb_helper_debug_enter(struct fb_info *info)
152 struct drm_fb_helper *helper = info->par;
153 const struct drm_crtc_helper_funcs *funcs;
154 struct drm_mode_set *mode_set;
156 list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
157 mutex_lock(&helper->client.modeset_mutex);
158 drm_client_for_each_modeset(mode_set, &helper->client) {
159 if (!mode_set->crtc->enabled)
162 funcs = mode_set->crtc->helper_private;
163 if (funcs->mode_set_base_atomic == NULL)
166 if (drm_drv_uses_atomic_modeset(mode_set->crtc->dev))
169 funcs->mode_set_base_atomic(mode_set->crtc,
173 ENTER_ATOMIC_MODE_SET);
175 mutex_unlock(&helper->client.modeset_mutex);
180 EXPORT_SYMBOL(drm_fb_helper_debug_enter);
183 * drm_fb_helper_debug_leave - implementation for &fb_ops.fb_debug_leave
184 * @info: fbdev registered by the helper
186 int drm_fb_helper_debug_leave(struct fb_info *info)
188 struct drm_fb_helper *helper = info->par;
189 struct drm_client_dev *client = &helper->client;
190 struct drm_device *dev = helper->dev;
191 struct drm_crtc *crtc;
192 const struct drm_crtc_helper_funcs *funcs;
193 struct drm_mode_set *mode_set;
194 struct drm_framebuffer *fb;
196 mutex_lock(&client->modeset_mutex);
197 drm_client_for_each_modeset(mode_set, client) {
198 crtc = mode_set->crtc;
199 if (drm_drv_uses_atomic_modeset(crtc->dev))
202 funcs = crtc->helper_private;
203 fb = crtc->primary->fb;
209 drm_err(dev, "no fb to restore?\n");
213 if (funcs->mode_set_base_atomic == NULL)
216 drm_fb_helper_restore_lut_atomic(mode_set->crtc);
217 funcs->mode_set_base_atomic(mode_set->crtc, fb, crtc->x,
218 crtc->y, LEAVE_ATOMIC_MODE_SET);
220 mutex_unlock(&client->modeset_mutex);
224 EXPORT_SYMBOL(drm_fb_helper_debug_leave);
227 __drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper,
233 if (!drm_fbdev_emulation || !fb_helper)
236 if (READ_ONCE(fb_helper->deferred_setup))
239 mutex_lock(&fb_helper->lock);
242 * Yes this is the _locked version which expects the master lock
243 * to be held. But for forced restores we're intentionally
244 * racing here, see drm_fb_helper_set_par().
246 ret = drm_client_modeset_commit_locked(&fb_helper->client);
248 ret = drm_client_modeset_commit(&fb_helper->client);
251 do_delayed = fb_helper->delayed_hotplug;
253 fb_helper->delayed_hotplug = false;
254 mutex_unlock(&fb_helper->lock);
257 drm_fb_helper_hotplug_event(fb_helper);
263 * drm_fb_helper_restore_fbdev_mode_unlocked - restore fbdev configuration
264 * @fb_helper: driver-allocated fbdev helper, can be NULL
266 * This should be called from driver's drm &drm_driver.lastclose callback
267 * when implementing an fbcon on top of kms using this helper. This ensures that
268 * the user isn't greeted with a black screen when e.g. X dies.
271 * Zero if everything went ok, negative error code otherwise.
273 int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
275 return __drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper, false);
277 EXPORT_SYMBOL(drm_fb_helper_restore_fbdev_mode_unlocked);
279 #ifdef CONFIG_MAGIC_SYSRQ
280 /* emergency restore, don't bother with error reporting */
281 static void drm_fb_helper_restore_work_fn(struct work_struct *ignored)
283 struct drm_fb_helper *helper;
285 mutex_lock(&kernel_fb_helper_lock);
286 list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
287 struct drm_device *dev = helper->dev;
289 if (dev->switch_power_state == DRM_SWITCH_POWER_OFF)
292 mutex_lock(&helper->lock);
293 drm_client_modeset_commit_locked(&helper->client);
294 mutex_unlock(&helper->lock);
296 mutex_unlock(&kernel_fb_helper_lock);
299 static DECLARE_WORK(drm_fb_helper_restore_work, drm_fb_helper_restore_work_fn);
301 static void drm_fb_helper_sysrq(int dummy1)
303 schedule_work(&drm_fb_helper_restore_work);
306 static const struct sysrq_key_op sysrq_drm_fb_helper_restore_op = {
307 .handler = drm_fb_helper_sysrq,
308 .help_msg = "force-fb(v)",
309 .action_msg = "Restore framebuffer console",
312 static const struct sysrq_key_op sysrq_drm_fb_helper_restore_op = { };
315 static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode)
317 struct drm_fb_helper *fb_helper = info->par;
319 mutex_lock(&fb_helper->lock);
320 drm_client_modeset_dpms(&fb_helper->client, dpms_mode);
321 mutex_unlock(&fb_helper->lock);
325 * drm_fb_helper_blank - implementation for &fb_ops.fb_blank
326 * @blank: desired blanking state
327 * @info: fbdev registered by the helper
329 int drm_fb_helper_blank(int blank, struct fb_info *info)
331 if (oops_in_progress)
335 /* Display: On; HSync: On, VSync: On */
336 case FB_BLANK_UNBLANK:
337 drm_fb_helper_dpms(info, DRM_MODE_DPMS_ON);
339 /* Display: Off; HSync: On, VSync: On */
340 case FB_BLANK_NORMAL:
341 drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
343 /* Display: Off; HSync: Off, VSync: On */
344 case FB_BLANK_HSYNC_SUSPEND:
345 drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
347 /* Display: Off; HSync: On, VSync: Off */
348 case FB_BLANK_VSYNC_SUSPEND:
349 drm_fb_helper_dpms(info, DRM_MODE_DPMS_SUSPEND);
351 /* Display: Off; HSync: Off, VSync: Off */
352 case FB_BLANK_POWERDOWN:
353 drm_fb_helper_dpms(info, DRM_MODE_DPMS_OFF);
358 EXPORT_SYMBOL(drm_fb_helper_blank);
360 static void drm_fb_helper_resume_worker(struct work_struct *work)
362 struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper,
366 fb_set_suspend(helper->info, 0);
370 static void drm_fb_helper_fb_dirty(struct drm_fb_helper *helper)
372 struct drm_device *dev = helper->dev;
373 struct drm_clip_rect *clip = &helper->damage_clip;
374 struct drm_clip_rect clip_copy;
378 if (drm_WARN_ON_ONCE(dev, !helper->funcs->fb_dirty))
381 spin_lock_irqsave(&helper->damage_lock, flags);
383 clip->x1 = clip->y1 = ~0;
384 clip->x2 = clip->y2 = 0;
385 spin_unlock_irqrestore(&helper->damage_lock, flags);
387 ret = helper->funcs->fb_dirty(helper, &clip_copy);
395 * Restore damage clip rectangle on errors. The next run
396 * of the damage worker will perform the update.
398 spin_lock_irqsave(&helper->damage_lock, flags);
399 clip->x1 = min_t(u32, clip->x1, clip_copy.x1);
400 clip->y1 = min_t(u32, clip->y1, clip_copy.y1);
401 clip->x2 = max_t(u32, clip->x2, clip_copy.x2);
402 clip->y2 = max_t(u32, clip->y2, clip_copy.y2);
403 spin_unlock_irqrestore(&helper->damage_lock, flags);
406 static void drm_fb_helper_damage_work(struct work_struct *work)
408 struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper, damage_work);
410 drm_fb_helper_fb_dirty(helper);
414 * drm_fb_helper_prepare - setup a drm_fb_helper structure
416 * @helper: driver-allocated fbdev helper structure to set up
417 * @funcs: pointer to structure of functions associate with this helper
419 * Sets up the bare minimum to make the framebuffer helper usable. This is
420 * useful to implement race-free initialization of the polling helpers.
422 void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
423 const struct drm_fb_helper_funcs *funcs)
425 INIT_LIST_HEAD(&helper->kernel_fb_list);
426 spin_lock_init(&helper->damage_lock);
427 INIT_WORK(&helper->resume_work, drm_fb_helper_resume_worker);
428 INIT_WORK(&helper->damage_work, drm_fb_helper_damage_work);
429 helper->damage_clip.x1 = helper->damage_clip.y1 = ~0;
430 mutex_init(&helper->lock);
431 helper->funcs = funcs;
434 EXPORT_SYMBOL(drm_fb_helper_prepare);
437 * drm_fb_helper_init - initialize a &struct drm_fb_helper
439 * @fb_helper: driver-allocated fbdev helper structure to initialize
441 * This allocates the structures for the fbdev helper with the given limits.
442 * Note that this won't yet touch the hardware (through the driver interfaces)
443 * nor register the fbdev. This is only done in drm_fb_helper_initial_config()
444 * to allow driver writes more control over the exact init sequence.
446 * Drivers must call drm_fb_helper_prepare() before calling this function.
449 * Zero if everything went ok, nonzero otherwise.
451 int drm_fb_helper_init(struct drm_device *dev,
452 struct drm_fb_helper *fb_helper)
457 * If this is not the generic fbdev client, initialize a drm_client
458 * without callbacks so we can use the modesets.
460 if (!fb_helper->client.funcs) {
461 ret = drm_client_init(dev, &fb_helper->client, "drm_fb_helper", NULL);
466 dev->fb_helper = fb_helper;
470 EXPORT_SYMBOL(drm_fb_helper_init);
473 * drm_fb_helper_alloc_info - allocate fb_info and some of its members
474 * @fb_helper: driver-allocated fbdev helper
476 * A helper to alloc fb_info and the member cmap. Called by the driver
477 * within the fb_probe fb_helper callback function. Drivers do not
478 * need to release the allocated fb_info structure themselves, this is
479 * automatically done when calling drm_fb_helper_fini().
482 * fb_info pointer if things went okay, pointer containing error code
485 struct fb_info *drm_fb_helper_alloc_info(struct drm_fb_helper *fb_helper)
487 struct device *dev = fb_helper->dev->dev;
488 struct fb_info *info;
491 info = framebuffer_alloc(0, dev);
493 return ERR_PTR(-ENOMEM);
495 ret = fb_alloc_cmap(&info->cmap, 256, 0);
499 fb_helper->info = info;
500 info->skip_vt_switch = true;
505 framebuffer_release(info);
508 EXPORT_SYMBOL(drm_fb_helper_alloc_info);
511 * drm_fb_helper_unregister_info - unregister fb_info framebuffer device
512 * @fb_helper: driver-allocated fbdev helper, can be NULL
514 * A wrapper around unregister_framebuffer, to release the fb_info
515 * framebuffer device. This must be called before releasing all resources for
516 * @fb_helper by calling drm_fb_helper_fini().
518 void drm_fb_helper_unregister_info(struct drm_fb_helper *fb_helper)
520 if (fb_helper && fb_helper->info)
521 unregister_framebuffer(fb_helper->info);
523 EXPORT_SYMBOL(drm_fb_helper_unregister_info);
526 * drm_fb_helper_fini - finialize a &struct drm_fb_helper
527 * @fb_helper: driver-allocated fbdev helper, can be NULL
529 * This cleans up all remaining resources associated with @fb_helper.
531 void drm_fb_helper_fini(struct drm_fb_helper *fb_helper)
533 struct fb_info *info;
538 fb_helper->dev->fb_helper = NULL;
540 if (!drm_fbdev_emulation)
543 cancel_work_sync(&fb_helper->resume_work);
544 cancel_work_sync(&fb_helper->damage_work);
546 info = fb_helper->info;
549 fb_dealloc_cmap(&info->cmap);
550 framebuffer_release(info);
552 fb_helper->info = NULL;
554 mutex_lock(&kernel_fb_helper_lock);
555 if (!list_empty(&fb_helper->kernel_fb_list)) {
556 list_del(&fb_helper->kernel_fb_list);
557 if (list_empty(&kernel_fb_helper_list))
558 unregister_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
560 mutex_unlock(&kernel_fb_helper_lock);
562 mutex_destroy(&fb_helper->lock);
564 if (!fb_helper->client.funcs)
565 drm_client_release(&fb_helper->client);
567 EXPORT_SYMBOL(drm_fb_helper_fini);
569 static void drm_fb_helper_add_damage_clip(struct drm_fb_helper *helper, u32 x, u32 y,
570 u32 width, u32 height)
572 struct drm_clip_rect *clip = &helper->damage_clip;
575 spin_lock_irqsave(&helper->damage_lock, flags);
576 clip->x1 = min_t(u32, clip->x1, x);
577 clip->y1 = min_t(u32, clip->y1, y);
578 clip->x2 = max_t(u32, clip->x2, x + width);
579 clip->y2 = max_t(u32, clip->y2, y + height);
580 spin_unlock_irqrestore(&helper->damage_lock, flags);
583 static void drm_fb_helper_damage(struct drm_fb_helper *helper, u32 x, u32 y,
584 u32 width, u32 height)
586 drm_fb_helper_add_damage_clip(helper, x, y, width, height);
588 schedule_work(&helper->damage_work);
592 * Convert memory region into area of scanlines and pixels per
593 * scanline. The parameters off and len must not reach beyond
594 * the end of the framebuffer.
596 static void drm_fb_helper_memory_range_to_clip(struct fb_info *info, off_t off, size_t len,
597 struct drm_rect *clip)
599 off_t end = off + len;
601 u32 y1 = off / info->fix.line_length;
602 u32 x2 = info->var.xres;
603 u32 y2 = DIV_ROUND_UP(end, info->fix.line_length);
605 if ((y2 - y1) == 1) {
607 * We've only written to a single scanline. Try to reduce
608 * the number of horizontal pixels that need an update.
610 off_t bit_off = (off % info->fix.line_length) * 8;
611 off_t bit_end = (end % info->fix.line_length) * 8;
613 x1 = bit_off / info->var.bits_per_pixel;
614 x2 = DIV_ROUND_UP(bit_end, info->var.bits_per_pixel);
617 drm_rect_init(clip, x1, y1, x2 - x1, y2 - y1);
621 * drm_fb_helper_deferred_io() - fbdev deferred_io callback function
622 * @info: fb_info struct pointer
623 * @pagereflist: list of mmap framebuffer pages that have to be flushed
625 * This function is used as the &fb_deferred_io.deferred_io
626 * callback function for flushing the fbdev mmap writes.
628 void drm_fb_helper_deferred_io(struct fb_info *info, struct list_head *pagereflist)
630 struct drm_fb_helper *helper = info->par;
631 unsigned long start, end, min_off, max_off;
632 struct fb_deferred_io_pageref *pageref;
633 struct drm_rect damage_area;
637 list_for_each_entry(pageref, pagereflist, list) {
638 start = pageref->offset;
639 end = start + PAGE_SIZE;
640 min_off = min(min_off, start);
641 max_off = max(max_off, end);
645 * As we can only track pages, we might reach beyond the end
646 * of the screen and account for non-existing scanlines. Hence,
647 * keep the covered memory area within the screen buffer.
649 max_off = min(max_off, info->screen_size);
651 if (min_off < max_off) {
652 drm_fb_helper_memory_range_to_clip(info, min_off, max_off - min_off, &damage_area);
653 drm_fb_helper_damage(helper, damage_area.x1, damage_area.y1,
654 drm_rect_width(&damage_area),
655 drm_rect_height(&damage_area));
658 EXPORT_SYMBOL(drm_fb_helper_deferred_io);
660 typedef ssize_t (*drm_fb_helper_read_screen)(struct fb_info *info, char __user *buf,
661 size_t count, loff_t pos);
663 static ssize_t __drm_fb_helper_read(struct fb_info *info, char __user *buf, size_t count,
664 loff_t *ppos, drm_fb_helper_read_screen read_screen)
670 if (info->screen_size)
671 total_size = info->screen_size;
673 total_size = info->fix.smem_len;
675 if (pos >= total_size)
677 if (count >= total_size)
679 if (total_size - count < pos)
680 count = total_size - pos;
682 if (info->fbops->fb_sync)
683 info->fbops->fb_sync(info);
685 ret = read_screen(info, buf, count, pos);
692 typedef ssize_t (*drm_fb_helper_write_screen)(struct fb_info *info, const char __user *buf,
693 size_t count, loff_t pos);
695 static ssize_t __drm_fb_helper_write(struct fb_info *info, const char __user *buf, size_t count,
696 loff_t *ppos, drm_fb_helper_write_screen write_screen)
703 if (info->screen_size)
704 total_size = info->screen_size;
706 total_size = info->fix.smem_len;
708 if (pos > total_size)
710 if (count > total_size) {
714 if (total_size - count < pos) {
717 count = total_size - pos;
720 if (info->fbops->fb_sync)
721 info->fbops->fb_sync(info);
724 * Copy to framebuffer even if we already logged an error. Emulates
725 * the behavior of the original fbdev implementation.
727 ret = write_screen(info, buf, count, pos);
729 return ret; /* return last error, if any */
731 return err; /* return previous error, if any */
738 static ssize_t drm_fb_helper_read_screen_buffer(struct fb_info *info, char __user *buf,
739 size_t count, loff_t pos)
741 const char *src = info->screen_buffer + pos;
743 if (copy_to_user(buf, src, count))
750 * drm_fb_helper_sys_read - Implements struct &fb_ops.fb_read for system memory
751 * @info: fb_info struct pointer
752 * @buf: userspace buffer to read from framebuffer memory
753 * @count: number of bytes to read from framebuffer memory
754 * @ppos: read offset within framebuffer memory
757 * The number of bytes read on success, or an error code otherwise.
759 ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
760 size_t count, loff_t *ppos)
762 return __drm_fb_helper_read(info, buf, count, ppos, drm_fb_helper_read_screen_buffer);
764 EXPORT_SYMBOL(drm_fb_helper_sys_read);
766 static ssize_t drm_fb_helper_write_screen_buffer(struct fb_info *info, const char __user *buf,
767 size_t count, loff_t pos)
769 char *dst = info->screen_buffer + pos;
771 if (copy_from_user(dst, buf, count))
778 * drm_fb_helper_sys_write - Implements struct &fb_ops.fb_write for system memory
779 * @info: fb_info struct pointer
780 * @buf: userspace buffer to write to framebuffer memory
781 * @count: number of bytes to write to framebuffer memory
782 * @ppos: write offset within framebuffer memory
785 * The number of bytes written on success, or an error code otherwise.
787 ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
788 size_t count, loff_t *ppos)
790 struct drm_fb_helper *helper = info->par;
793 struct drm_rect damage_area;
795 ret = __drm_fb_helper_write(info, buf, count, ppos, drm_fb_helper_write_screen_buffer);
799 if (helper->funcs->fb_dirty) {
800 drm_fb_helper_memory_range_to_clip(info, pos, ret, &damage_area);
801 drm_fb_helper_damage(helper, damage_area.x1, damage_area.y1,
802 drm_rect_width(&damage_area),
803 drm_rect_height(&damage_area));
808 EXPORT_SYMBOL(drm_fb_helper_sys_write);
811 * drm_fb_helper_sys_fillrect - wrapper around sys_fillrect
812 * @info: fbdev registered by the helper
813 * @rect: info about rectangle to fill
815 * A wrapper around sys_fillrect implemented by fbdev core
817 void drm_fb_helper_sys_fillrect(struct fb_info *info,
818 const struct fb_fillrect *rect)
820 struct drm_fb_helper *helper = info->par;
822 sys_fillrect(info, rect);
824 if (helper->funcs->fb_dirty)
825 drm_fb_helper_damage(helper, rect->dx, rect->dy, rect->width, rect->height);
827 EXPORT_SYMBOL(drm_fb_helper_sys_fillrect);
830 * drm_fb_helper_sys_copyarea - wrapper around sys_copyarea
831 * @info: fbdev registered by the helper
832 * @area: info about area to copy
834 * A wrapper around sys_copyarea implemented by fbdev core
836 void drm_fb_helper_sys_copyarea(struct fb_info *info,
837 const struct fb_copyarea *area)
839 struct drm_fb_helper *helper = info->par;
841 sys_copyarea(info, area);
843 if (helper->funcs->fb_dirty)
844 drm_fb_helper_damage(helper, area->dx, area->dy, area->width, area->height);
846 EXPORT_SYMBOL(drm_fb_helper_sys_copyarea);
849 * drm_fb_helper_sys_imageblit - wrapper around sys_imageblit
850 * @info: fbdev registered by the helper
851 * @image: info about image to blit
853 * A wrapper around sys_imageblit implemented by fbdev core
855 void drm_fb_helper_sys_imageblit(struct fb_info *info,
856 const struct fb_image *image)
858 struct drm_fb_helper *helper = info->par;
860 sys_imageblit(info, image);
862 if (helper->funcs->fb_dirty)
863 drm_fb_helper_damage(helper, image->dx, image->dy, image->width, image->height);
865 EXPORT_SYMBOL(drm_fb_helper_sys_imageblit);
867 static ssize_t fb_read_screen_base(struct fb_info *info, char __user *buf, size_t count,
870 const char __iomem *src = info->screen_base + pos;
871 size_t alloc_size = min_t(size_t, count, PAGE_SIZE);
876 tmp = kmalloc(alloc_size, GFP_KERNEL);
881 size_t c = min_t(size_t, count, alloc_size);
883 memcpy_fromio(tmp, src, c);
884 if (copy_to_user(buf, tmp, c)) {
897 return ret ? ret : err;
901 * drm_fb_helper_cfb_read - Implements struct &fb_ops.fb_read for I/O memory
902 * @info: fb_info struct pointer
903 * @buf: userspace buffer to read from framebuffer memory
904 * @count: number of bytes to read from framebuffer memory
905 * @ppos: read offset within framebuffer memory
908 * The number of bytes read on success, or an error code otherwise.
910 ssize_t drm_fb_helper_cfb_read(struct fb_info *info, char __user *buf,
911 size_t count, loff_t *ppos)
913 return __drm_fb_helper_read(info, buf, count, ppos, fb_read_screen_base);
915 EXPORT_SYMBOL(drm_fb_helper_cfb_read);
917 static ssize_t fb_write_screen_base(struct fb_info *info, const char __user *buf, size_t count,
920 char __iomem *dst = info->screen_base + pos;
921 size_t alloc_size = min_t(size_t, count, PAGE_SIZE);
926 tmp = kmalloc(alloc_size, GFP_KERNEL);
931 size_t c = min_t(size_t, count, alloc_size);
933 if (copy_from_user(tmp, buf, c)) {
937 memcpy_toio(dst, tmp, c);
947 return ret ? ret : err;
951 * drm_fb_helper_cfb_write - Implements struct &fb_ops.fb_write for I/O memory
952 * @info: fb_info struct pointer
953 * @buf: userspace buffer to write to framebuffer memory
954 * @count: number of bytes to write to framebuffer memory
955 * @ppos: write offset within framebuffer memory
958 * The number of bytes written on success, or an error code otherwise.
960 ssize_t drm_fb_helper_cfb_write(struct fb_info *info, const char __user *buf,
961 size_t count, loff_t *ppos)
963 struct drm_fb_helper *helper = info->par;
966 struct drm_rect damage_area;
968 ret = __drm_fb_helper_write(info, buf, count, ppos, fb_write_screen_base);
972 if (helper->funcs->fb_dirty) {
973 drm_fb_helper_memory_range_to_clip(info, pos, ret, &damage_area);
974 drm_fb_helper_damage(helper, damage_area.x1, damage_area.y1,
975 drm_rect_width(&damage_area),
976 drm_rect_height(&damage_area));
981 EXPORT_SYMBOL(drm_fb_helper_cfb_write);
984 * drm_fb_helper_cfb_fillrect - wrapper around cfb_fillrect
985 * @info: fbdev registered by the helper
986 * @rect: info about rectangle to fill
988 * A wrapper around cfb_fillrect implemented by fbdev core
990 void drm_fb_helper_cfb_fillrect(struct fb_info *info,
991 const struct fb_fillrect *rect)
993 struct drm_fb_helper *helper = info->par;
995 cfb_fillrect(info, rect);
997 if (helper->funcs->fb_dirty)
998 drm_fb_helper_damage(helper, rect->dx, rect->dy, rect->width, rect->height);
1000 EXPORT_SYMBOL(drm_fb_helper_cfb_fillrect);
1003 * drm_fb_helper_cfb_copyarea - wrapper around cfb_copyarea
1004 * @info: fbdev registered by the helper
1005 * @area: info about area to copy
1007 * A wrapper around cfb_copyarea implemented by fbdev core
1009 void drm_fb_helper_cfb_copyarea(struct fb_info *info,
1010 const struct fb_copyarea *area)
1012 struct drm_fb_helper *helper = info->par;
1014 cfb_copyarea(info, area);
1016 if (helper->funcs->fb_dirty)
1017 drm_fb_helper_damage(helper, area->dx, area->dy, area->width, area->height);
1019 EXPORT_SYMBOL(drm_fb_helper_cfb_copyarea);
1022 * drm_fb_helper_cfb_imageblit - wrapper around cfb_imageblit
1023 * @info: fbdev registered by the helper
1024 * @image: info about image to blit
1026 * A wrapper around cfb_imageblit implemented by fbdev core
1028 void drm_fb_helper_cfb_imageblit(struct fb_info *info,
1029 const struct fb_image *image)
1031 struct drm_fb_helper *helper = info->par;
1033 cfb_imageblit(info, image);
1035 if (helper->funcs->fb_dirty)
1036 drm_fb_helper_damage(helper, image->dx, image->dy, image->width, image->height);
1038 EXPORT_SYMBOL(drm_fb_helper_cfb_imageblit);
1041 * drm_fb_helper_set_suspend - wrapper around fb_set_suspend
1042 * @fb_helper: driver-allocated fbdev helper, can be NULL
1043 * @suspend: whether to suspend or resume
1045 * A wrapper around fb_set_suspend implemented by fbdev core.
1046 * Use drm_fb_helper_set_suspend_unlocked() if you don't need to take
1049 void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend)
1051 if (fb_helper && fb_helper->info)
1052 fb_set_suspend(fb_helper->info, suspend);
1054 EXPORT_SYMBOL(drm_fb_helper_set_suspend);
1057 * drm_fb_helper_set_suspend_unlocked - wrapper around fb_set_suspend that also
1058 * takes the console lock
1059 * @fb_helper: driver-allocated fbdev helper, can be NULL
1060 * @suspend: whether to suspend or resume
1062 * A wrapper around fb_set_suspend() that takes the console lock. If the lock
1063 * isn't available on resume, a worker is tasked with waiting for the lock
1064 * to become available. The console lock can be pretty contented on resume
1065 * due to all the printk activity.
1067 * This function can be called multiple times with the same state since
1068 * &fb_info.state is checked to see if fbdev is running or not before locking.
1070 * Use drm_fb_helper_set_suspend() if you need to take the lock yourself.
1072 void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
1075 if (!fb_helper || !fb_helper->info)
1078 /* make sure there's no pending/ongoing resume */
1079 flush_work(&fb_helper->resume_work);
1082 if (fb_helper->info->state != FBINFO_STATE_RUNNING)
1088 if (fb_helper->info->state == FBINFO_STATE_RUNNING)
1091 if (!console_trylock()) {
1092 schedule_work(&fb_helper->resume_work);
1097 fb_set_suspend(fb_helper->info, suspend);
1100 EXPORT_SYMBOL(drm_fb_helper_set_suspend_unlocked);
1102 static int setcmap_pseudo_palette(struct fb_cmap *cmap, struct fb_info *info)
1104 u32 *palette = (u32 *)info->pseudo_palette;
1107 if (cmap->start + cmap->len > 16)
1110 for (i = 0; i < cmap->len; ++i) {
1111 u16 red = cmap->red[i];
1112 u16 green = cmap->green[i];
1113 u16 blue = cmap->blue[i];
1116 red >>= 16 - info->var.red.length;
1117 green >>= 16 - info->var.green.length;
1118 blue >>= 16 - info->var.blue.length;
1119 value = (red << info->var.red.offset) |
1120 (green << info->var.green.offset) |
1121 (blue << info->var.blue.offset);
1122 if (info->var.transp.length > 0) {
1123 u32 mask = (1 << info->var.transp.length) - 1;
1125 mask <<= info->var.transp.offset;
1128 palette[cmap->start + i] = value;
1134 static int setcmap_legacy(struct fb_cmap *cmap, struct fb_info *info)
1136 struct drm_fb_helper *fb_helper = info->par;
1137 struct drm_mode_set *modeset;
1138 struct drm_crtc *crtc;
1142 drm_modeset_lock_all(fb_helper->dev);
1143 drm_client_for_each_modeset(modeset, &fb_helper->client) {
1144 crtc = modeset->crtc;
1145 if (!crtc->funcs->gamma_set || !crtc->gamma_size) {
1150 if (cmap->start + cmap->len > crtc->gamma_size) {
1155 r = crtc->gamma_store;
1156 g = r + crtc->gamma_size;
1157 b = g + crtc->gamma_size;
1159 memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
1160 memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
1161 memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
1163 ret = crtc->funcs->gamma_set(crtc, r, g, b,
1164 crtc->gamma_size, NULL);
1169 drm_modeset_unlock_all(fb_helper->dev);
1174 static struct drm_property_blob *setcmap_new_gamma_lut(struct drm_crtc *crtc,
1175 struct fb_cmap *cmap)
1177 struct drm_device *dev = crtc->dev;
1178 struct drm_property_blob *gamma_lut;
1179 struct drm_color_lut *lut;
1180 int size = crtc->gamma_size;
1183 if (!size || cmap->start + cmap->len > size)
1184 return ERR_PTR(-EINVAL);
1186 gamma_lut = drm_property_create_blob(dev, sizeof(*lut) * size, NULL);
1187 if (IS_ERR(gamma_lut))
1190 lut = gamma_lut->data;
1191 if (cmap->start || cmap->len != size) {
1192 u16 *r = crtc->gamma_store;
1193 u16 *g = r + crtc->gamma_size;
1194 u16 *b = g + crtc->gamma_size;
1196 for (i = 0; i < cmap->start; i++) {
1198 lut[i].green = g[i];
1201 for (i = cmap->start + cmap->len; i < size; i++) {
1203 lut[i].green = g[i];
1208 for (i = 0; i < cmap->len; i++) {
1209 lut[cmap->start + i].red = cmap->red[i];
1210 lut[cmap->start + i].green = cmap->green[i];
1211 lut[cmap->start + i].blue = cmap->blue[i];
1217 static int setcmap_atomic(struct fb_cmap *cmap, struct fb_info *info)
1219 struct drm_fb_helper *fb_helper = info->par;
1220 struct drm_device *dev = fb_helper->dev;
1221 struct drm_property_blob *gamma_lut = NULL;
1222 struct drm_modeset_acquire_ctx ctx;
1223 struct drm_crtc_state *crtc_state;
1224 struct drm_atomic_state *state;
1225 struct drm_mode_set *modeset;
1226 struct drm_crtc *crtc;
1231 drm_modeset_acquire_init(&ctx, 0);
1233 state = drm_atomic_state_alloc(dev);
1239 state->acquire_ctx = &ctx;
1241 drm_client_for_each_modeset(modeset, &fb_helper->client) {
1242 crtc = modeset->crtc;
1245 gamma_lut = setcmap_new_gamma_lut(crtc, cmap);
1246 if (IS_ERR(gamma_lut)) {
1247 ret = PTR_ERR(gamma_lut);
1252 crtc_state = drm_atomic_get_crtc_state(state, crtc);
1253 if (IS_ERR(crtc_state)) {
1254 ret = PTR_ERR(crtc_state);
1259 * FIXME: This always uses gamma_lut. Some HW have only
1260 * degamma_lut, in which case we should reset gamma_lut and set
1261 * degamma_lut. See drm_crtc_legacy_gamma_set().
1263 replaced = drm_property_replace_blob(&crtc_state->degamma_lut,
1265 replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
1266 replaced |= drm_property_replace_blob(&crtc_state->gamma_lut,
1268 crtc_state->color_mgmt_changed |= replaced;
1271 ret = drm_atomic_commit(state);
1275 drm_client_for_each_modeset(modeset, &fb_helper->client) {
1276 crtc = modeset->crtc;
1278 r = crtc->gamma_store;
1279 g = r + crtc->gamma_size;
1280 b = g + crtc->gamma_size;
1282 memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
1283 memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
1284 memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
1288 if (ret == -EDEADLK)
1291 drm_property_blob_put(gamma_lut);
1292 drm_atomic_state_put(state);
1294 drm_modeset_drop_locks(&ctx);
1295 drm_modeset_acquire_fini(&ctx);
1300 drm_atomic_state_clear(state);
1301 drm_modeset_backoff(&ctx);
1306 * drm_fb_helper_setcmap - implementation for &fb_ops.fb_setcmap
1307 * @cmap: cmap to set
1308 * @info: fbdev registered by the helper
1310 int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
1312 struct drm_fb_helper *fb_helper = info->par;
1313 struct drm_device *dev = fb_helper->dev;
1316 if (oops_in_progress)
1319 mutex_lock(&fb_helper->lock);
1321 if (!drm_master_internal_acquire(dev)) {
1326 mutex_lock(&fb_helper->client.modeset_mutex);
1327 if (info->fix.visual == FB_VISUAL_TRUECOLOR)
1328 ret = setcmap_pseudo_palette(cmap, info);
1329 else if (drm_drv_uses_atomic_modeset(fb_helper->dev))
1330 ret = setcmap_atomic(cmap, info);
1332 ret = setcmap_legacy(cmap, info);
1333 mutex_unlock(&fb_helper->client.modeset_mutex);
1335 drm_master_internal_release(dev);
1337 mutex_unlock(&fb_helper->lock);
1341 EXPORT_SYMBOL(drm_fb_helper_setcmap);
1344 * drm_fb_helper_ioctl - legacy ioctl implementation
1345 * @info: fbdev registered by the helper
1346 * @cmd: ioctl command
1347 * @arg: ioctl argument
1349 * A helper to implement the standard fbdev ioctl. Only
1350 * FBIO_WAITFORVSYNC is implemented for now.
1352 int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
1355 struct drm_fb_helper *fb_helper = info->par;
1356 struct drm_device *dev = fb_helper->dev;
1357 struct drm_crtc *crtc;
1360 mutex_lock(&fb_helper->lock);
1361 if (!drm_master_internal_acquire(dev)) {
1367 case FBIO_WAITFORVSYNC:
1369 * Only consider the first CRTC.
1371 * This ioctl is supposed to take the CRTC number as
1372 * an argument, but in fbdev times, what that number
1373 * was supposed to be was quite unclear, different
1374 * drivers were passing that argument differently
1375 * (some by reference, some by value), and most of the
1376 * userspace applications were just hardcoding 0 as an
1379 * The first CRTC should be the integrated panel on
1380 * most drivers, so this is the best choice we can
1381 * make. If we're not smart enough here, one should
1382 * just consider switch the userspace to KMS.
1384 crtc = fb_helper->client.modesets[0].crtc;
1387 * Only wait for a vblank event if the CRTC is
1388 * enabled, otherwise just don't do anythintg,
1389 * not even report an error.
1391 ret = drm_crtc_vblank_get(crtc);
1393 drm_crtc_wait_one_vblank(crtc);
1394 drm_crtc_vblank_put(crtc);
1403 drm_master_internal_release(dev);
1405 mutex_unlock(&fb_helper->lock);
1408 EXPORT_SYMBOL(drm_fb_helper_ioctl);
1410 static bool drm_fb_pixel_format_equal(const struct fb_var_screeninfo *var_1,
1411 const struct fb_var_screeninfo *var_2)
1413 return var_1->bits_per_pixel == var_2->bits_per_pixel &&
1414 var_1->grayscale == var_2->grayscale &&
1415 var_1->red.offset == var_2->red.offset &&
1416 var_1->red.length == var_2->red.length &&
1417 var_1->red.msb_right == var_2->red.msb_right &&
1418 var_1->green.offset == var_2->green.offset &&
1419 var_1->green.length == var_2->green.length &&
1420 var_1->green.msb_right == var_2->green.msb_right &&
1421 var_1->blue.offset == var_2->blue.offset &&
1422 var_1->blue.length == var_2->blue.length &&
1423 var_1->blue.msb_right == var_2->blue.msb_right &&
1424 var_1->transp.offset == var_2->transp.offset &&
1425 var_1->transp.length == var_2->transp.length &&
1426 var_1->transp.msb_right == var_2->transp.msb_right;
1429 static void drm_fb_helper_fill_pixel_fmt(struct fb_var_screeninfo *var,
1430 const struct drm_format_info *format)
1432 u8 depth = format->depth;
1434 if (format->is_color_indexed) {
1435 var->red.offset = 0;
1436 var->green.offset = 0;
1437 var->blue.offset = 0;
1438 var->red.length = depth;
1439 var->green.length = depth;
1440 var->blue.length = depth;
1441 var->transp.offset = 0;
1442 var->transp.length = 0;
1448 var->red.offset = 10;
1449 var->green.offset = 5;
1450 var->blue.offset = 0;
1451 var->red.length = 5;
1452 var->green.length = 5;
1453 var->blue.length = 5;
1454 var->transp.offset = 15;
1455 var->transp.length = 1;
1458 var->red.offset = 11;
1459 var->green.offset = 5;
1460 var->blue.offset = 0;
1461 var->red.length = 5;
1462 var->green.length = 6;
1463 var->blue.length = 5;
1464 var->transp.offset = 0;
1467 var->red.offset = 16;
1468 var->green.offset = 8;
1469 var->blue.offset = 0;
1470 var->red.length = 8;
1471 var->green.length = 8;
1472 var->blue.length = 8;
1473 var->transp.offset = 0;
1474 var->transp.length = 0;
1477 var->red.offset = 16;
1478 var->green.offset = 8;
1479 var->blue.offset = 0;
1480 var->red.length = 8;
1481 var->green.length = 8;
1482 var->blue.length = 8;
1483 var->transp.offset = 24;
1484 var->transp.length = 8;
1492 * drm_fb_helper_check_var - implementation for &fb_ops.fb_check_var
1493 * @var: screeninfo to check
1494 * @info: fbdev registered by the helper
1496 int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
1497 struct fb_info *info)
1499 struct drm_fb_helper *fb_helper = info->par;
1500 struct drm_framebuffer *fb = fb_helper->fb;
1501 const struct drm_format_info *format = fb->format;
1502 struct drm_device *dev = fb_helper->dev;
1505 if (in_dbg_master())
1508 if (var->pixclock != 0) {
1509 drm_dbg_kms(dev, "fbdev emulation doesn't support changing the pixel clock, value of pixclock is ignored\n");
1513 switch (format->format) {
1517 /* supported format with sub-byte pixels */
1521 if ((drm_format_info_block_width(format, 0) > 1) ||
1522 (drm_format_info_block_height(format, 0) > 1))
1528 * Changes struct fb_var_screeninfo are currently not pushed back
1529 * to KMS, hence fail if different settings are requested.
1531 bpp = drm_format_info_bpp(format, 0);
1532 if (var->bits_per_pixel > bpp ||
1533 var->xres > fb->width || var->yres > fb->height ||
1534 var->xres_virtual > fb->width || var->yres_virtual > fb->height) {
1535 drm_dbg_kms(dev, "fb requested width/height/bpp can't fit in current fb "
1536 "request %dx%d-%d (virtual %dx%d) > %dx%d-%d\n",
1537 var->xres, var->yres, var->bits_per_pixel,
1538 var->xres_virtual, var->yres_virtual,
1539 fb->width, fb->height, bpp);
1544 * Workaround for SDL 1.2, which is known to be setting all pixel format
1545 * fields values to zero in some cases. We treat this situation as a
1546 * kind of "use some reasonable autodetected values".
1548 if (!var->red.offset && !var->green.offset &&
1549 !var->blue.offset && !var->transp.offset &&
1550 !var->red.length && !var->green.length &&
1551 !var->blue.length && !var->transp.length &&
1552 !var->red.msb_right && !var->green.msb_right &&
1553 !var->blue.msb_right && !var->transp.msb_right) {
1554 drm_fb_helper_fill_pixel_fmt(var, format);
1558 * Likewise, bits_per_pixel should be rounded up to a supported value.
1560 var->bits_per_pixel = bpp;
1563 * drm fbdev emulation doesn't support changing the pixel format at all,
1564 * so reject all pixel format changing requests.
1566 if (!drm_fb_pixel_format_equal(var, &info->var)) {
1567 drm_dbg_kms(dev, "fbdev emulation doesn't support changing the pixel format\n");
1573 EXPORT_SYMBOL(drm_fb_helper_check_var);
1576 * drm_fb_helper_set_par - implementation for &fb_ops.fb_set_par
1577 * @info: fbdev registered by the helper
1579 * This will let fbcon do the mode init and is called at initialization time by
1580 * the fbdev core when registering the driver, and later on through the hotplug
1583 int drm_fb_helper_set_par(struct fb_info *info)
1585 struct drm_fb_helper *fb_helper = info->par;
1586 struct fb_var_screeninfo *var = &info->var;
1589 if (oops_in_progress)
1592 if (var->pixclock != 0) {
1593 drm_err(fb_helper->dev, "PIXEL CLOCK SET\n");
1598 * Normally we want to make sure that a kms master takes precedence over
1599 * fbdev, to avoid fbdev flickering and occasionally stealing the
1600 * display status. But Xorg first sets the vt back to text mode using
1601 * the KDSET IOCTL with KD_TEXT, and only after that drops the master
1602 * status when exiting.
1604 * In the past this was caught by drm_fb_helper_lastclose(), but on
1605 * modern systems where logind always keeps a drm fd open to orchestrate
1606 * the vt switching, this doesn't work.
1608 * To not break the userspace ABI we have this special case here, which
1609 * is only used for the above case. Everything else uses the normal
1610 * commit function, which ensures that we never steal the display from
1611 * an active drm master.
1613 force = var->activate & FB_ACTIVATE_KD_TEXT;
1615 __drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper, force);
1619 EXPORT_SYMBOL(drm_fb_helper_set_par);
1621 static void pan_set(struct drm_fb_helper *fb_helper, int x, int y)
1623 struct drm_mode_set *mode_set;
1625 mutex_lock(&fb_helper->client.modeset_mutex);
1626 drm_client_for_each_modeset(mode_set, &fb_helper->client) {
1630 mutex_unlock(&fb_helper->client.modeset_mutex);
1633 static int pan_display_atomic(struct fb_var_screeninfo *var,
1634 struct fb_info *info)
1636 struct drm_fb_helper *fb_helper = info->par;
1639 pan_set(fb_helper, var->xoffset, var->yoffset);
1641 ret = drm_client_modeset_commit_locked(&fb_helper->client);
1643 info->var.xoffset = var->xoffset;
1644 info->var.yoffset = var->yoffset;
1646 pan_set(fb_helper, info->var.xoffset, info->var.yoffset);
1651 static int pan_display_legacy(struct fb_var_screeninfo *var,
1652 struct fb_info *info)
1654 struct drm_fb_helper *fb_helper = info->par;
1655 struct drm_client_dev *client = &fb_helper->client;
1656 struct drm_mode_set *modeset;
1659 mutex_lock(&client->modeset_mutex);
1660 drm_modeset_lock_all(fb_helper->dev);
1661 drm_client_for_each_modeset(modeset, client) {
1662 modeset->x = var->xoffset;
1663 modeset->y = var->yoffset;
1665 if (modeset->num_connectors) {
1666 ret = drm_mode_set_config_internal(modeset);
1668 info->var.xoffset = var->xoffset;
1669 info->var.yoffset = var->yoffset;
1673 drm_modeset_unlock_all(fb_helper->dev);
1674 mutex_unlock(&client->modeset_mutex);
1680 * drm_fb_helper_pan_display - implementation for &fb_ops.fb_pan_display
1681 * @var: updated screen information
1682 * @info: fbdev registered by the helper
1684 int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
1685 struct fb_info *info)
1687 struct drm_fb_helper *fb_helper = info->par;
1688 struct drm_device *dev = fb_helper->dev;
1691 if (oops_in_progress)
1694 mutex_lock(&fb_helper->lock);
1695 if (!drm_master_internal_acquire(dev)) {
1700 if (drm_drv_uses_atomic_modeset(dev))
1701 ret = pan_display_atomic(var, info);
1703 ret = pan_display_legacy(var, info);
1705 drm_master_internal_release(dev);
1707 mutex_unlock(&fb_helper->lock);
1711 EXPORT_SYMBOL(drm_fb_helper_pan_display);
1713 static uint32_t drm_fb_helper_find_format(struct drm_fb_helper *fb_helper, const uint32_t *formats,
1714 size_t format_count, uint32_t bpp, uint32_t depth)
1716 struct drm_device *dev = fb_helper->dev;
1721 * Do not consider YUV or other complicated formats
1722 * for framebuffers. This means only legacy formats
1723 * are supported (fmt->depth is a legacy field), but
1724 * the framebuffer emulation can only deal with such
1725 * formats, specifically RGB/BGA formats.
1727 format = drm_mode_legacy_fb_format(bpp, depth);
1731 for (i = 0; i < format_count; ++i) {
1732 if (formats[i] == format)
1737 /* We found nothing. */
1738 drm_warn(dev, "bpp/depth value of %u/%u not supported\n", bpp, depth);
1740 return DRM_FORMAT_INVALID;
1743 static uint32_t drm_fb_helper_find_color_mode_format(struct drm_fb_helper *fb_helper,
1744 const uint32_t *formats, size_t format_count,
1745 unsigned int color_mode)
1747 struct drm_device *dev = fb_helper->dev;
1748 uint32_t bpp, depth;
1750 switch (color_mode) {
1757 bpp = depth = color_mode;
1768 drm_info(dev, "unsupported color mode of %d\n", color_mode);
1769 return DRM_FORMAT_INVALID;
1772 return drm_fb_helper_find_format(fb_helper, formats, format_count, bpp, depth);
1775 static int __drm_fb_helper_find_sizes(struct drm_fb_helper *fb_helper, int preferred_bpp,
1776 struct drm_fb_helper_surface_size *sizes)
1778 struct drm_client_dev *client = &fb_helper->client;
1779 struct drm_device *dev = fb_helper->dev;
1781 struct drm_connector_list_iter conn_iter;
1782 struct drm_connector *connector;
1783 struct drm_mode_set *mode_set;
1784 uint32_t surface_format = DRM_FORMAT_INVALID;
1785 const struct drm_format_info *info;
1787 memset(sizes, 0, sizeof(*sizes));
1788 sizes->fb_width = (u32)-1;
1789 sizes->fb_height = (u32)-1;
1791 drm_client_for_each_modeset(mode_set, client) {
1792 struct drm_crtc *crtc = mode_set->crtc;
1793 struct drm_plane *plane = crtc->primary;
1795 drm_dbg_kms(dev, "test CRTC %u primary plane\n", drm_crtc_index(crtc));
1797 drm_connector_list_iter_begin(fb_helper->dev, &conn_iter);
1798 drm_client_for_each_connector_iter(connector, &conn_iter) {
1799 struct drm_cmdline_mode *cmdline_mode = &connector->cmdline_mode;
1801 if (!cmdline_mode->bpp_specified)
1804 surface_format = drm_fb_helper_find_color_mode_format(fb_helper,
1805 plane->format_types,
1806 plane->format_count,
1808 if (surface_format != DRM_FORMAT_INVALID)
1809 break; /* found supported format */
1811 drm_connector_list_iter_end(&conn_iter);
1813 if (surface_format != DRM_FORMAT_INVALID)
1814 break; /* found supported format */
1816 /* try preferred color mode */
1817 surface_format = drm_fb_helper_find_color_mode_format(fb_helper,
1818 plane->format_types,
1819 plane->format_count,
1821 if (surface_format != DRM_FORMAT_INVALID)
1822 break; /* found supported format */
1825 if (surface_format == DRM_FORMAT_INVALID) {
1827 * If none of the given color modes works, fall back
1828 * to XRGB8888. Drivers are expected to provide this
1829 * format for compatibility with legacy applications.
1831 drm_warn(dev, "No compatible format found\n");
1832 surface_format = drm_driver_legacy_fb_format(dev, 32, 24);
1835 info = drm_format_info(surface_format);
1836 sizes->surface_bpp = drm_format_info_bpp(info, 0);
1837 sizes->surface_depth = info->depth;
1839 /* first up get a count of crtcs now in use and new min/maxes width/heights */
1841 drm_client_for_each_modeset(mode_set, client) {
1842 struct drm_display_mode *desired_mode;
1844 /* in case of tile group, are we the last tile vert or horiz?
1845 * If no tile group you are always the last one both vertically
1848 bool lastv = true, lasth = true;
1850 desired_mode = mode_set->mode;
1860 sizes->surface_width =
1861 max_t(u32, desired_mode->hdisplay + x, sizes->surface_width);
1862 sizes->surface_height =
1863 max_t(u32, desired_mode->vdisplay + y, sizes->surface_height);
1865 for (j = 0; j < mode_set->num_connectors; j++) {
1866 struct drm_connector *connector = mode_set->connectors[j];
1868 if (connector->has_tile &&
1869 desired_mode->hdisplay == connector->tile_h_size &&
1870 desired_mode->vdisplay == connector->tile_v_size) {
1871 lasth = (connector->tile_h_loc == (connector->num_h_tile - 1));
1872 lastv = (connector->tile_v_loc == (connector->num_v_tile - 1));
1873 /* cloning to multiple tiles is just crazy-talk, so: */
1879 sizes->fb_width = min_t(u32, desired_mode->hdisplay + x, sizes->fb_width);
1881 sizes->fb_height = min_t(u32, desired_mode->vdisplay + y, sizes->fb_height);
1884 if (crtc_count == 0 || sizes->fb_width == -1 || sizes->fb_height == -1) {
1885 drm_info(dev, "Cannot find any crtc or sizes\n");
1892 static int drm_fb_helper_find_sizes(struct drm_fb_helper *fb_helper, int preferred_bpp,
1893 struct drm_fb_helper_surface_size *sizes)
1895 struct drm_client_dev *client = &fb_helper->client;
1896 struct drm_device *dev = fb_helper->dev;
1897 struct drm_mode_config *config = &dev->mode_config;
1900 mutex_lock(&client->modeset_mutex);
1901 ret = __drm_fb_helper_find_sizes(fb_helper, preferred_bpp, sizes);
1902 mutex_unlock(&client->modeset_mutex);
1907 /* Handle our overallocation */
1908 sizes->surface_height *= drm_fbdev_overalloc;
1909 sizes->surface_height /= 100;
1910 if (sizes->surface_height > config->max_height) {
1911 drm_dbg_kms(dev, "Fbdev over-allocation too large; clamping height to %d\n",
1912 config->max_height);
1913 sizes->surface_height = config->max_height;
1920 * Allocates the backing storage and sets up the fbdev info structure through
1921 * the ->fb_probe callback.
1923 static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
1926 struct drm_client_dev *client = &fb_helper->client;
1927 struct drm_fb_helper_surface_size sizes;
1930 ret = drm_fb_helper_find_sizes(fb_helper, preferred_bpp, &sizes);
1932 /* First time: disable all crtc's.. */
1933 if (!fb_helper->deferred_setup)
1934 drm_client_modeset_commit(client);
1938 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
1939 fb_helper->hint_leak_smem_start = drm_leak_fbdev_smem;
1942 /* push down into drivers */
1943 ret = (*fb_helper->funcs->fb_probe)(fb_helper, &sizes);
1947 strcpy(fb_helper->fb->comm, "[fbcon]");
1951 static void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
1952 bool is_color_indexed)
1954 info->fix.type = FB_TYPE_PACKED_PIXELS;
1955 info->fix.visual = is_color_indexed ? FB_VISUAL_PSEUDOCOLOR
1956 : FB_VISUAL_TRUECOLOR;
1957 info->fix.mmio_start = 0;
1958 info->fix.mmio_len = 0;
1959 info->fix.type_aux = 0;
1960 info->fix.xpanstep = 1; /* doing it in hw */
1961 info->fix.ypanstep = 1; /* doing it in hw */
1962 info->fix.ywrapstep = 0;
1963 info->fix.accel = FB_ACCEL_NONE;
1965 info->fix.line_length = pitch;
1968 static void drm_fb_helper_fill_var(struct fb_info *info,
1969 struct drm_fb_helper *fb_helper,
1970 uint32_t fb_width, uint32_t fb_height)
1972 struct drm_framebuffer *fb = fb_helper->fb;
1973 const struct drm_format_info *format = fb->format;
1975 switch (format->format) {
1979 /* supported format with sub-byte pixels */
1983 WARN_ON((drm_format_info_block_width(format, 0) > 1) ||
1984 (drm_format_info_block_height(format, 0) > 1));
1988 info->pseudo_palette = fb_helper->pseudo_palette;
1989 info->var.xres_virtual = fb->width;
1990 info->var.yres_virtual = fb->height;
1991 info->var.bits_per_pixel = drm_format_info_bpp(format, 0);
1992 info->var.accel_flags = FB_ACCELF_TEXT;
1993 info->var.xoffset = 0;
1994 info->var.yoffset = 0;
1995 info->var.activate = FB_ACTIVATE_NOW;
1997 drm_fb_helper_fill_pixel_fmt(&info->var, format);
1999 info->var.xres = fb_width;
2000 info->var.yres = fb_height;
2004 * drm_fb_helper_fill_info - initializes fbdev information
2005 * @info: fbdev instance to set up
2006 * @fb_helper: fb helper instance to use as template
2007 * @sizes: describes fbdev size and scanout surface size
2009 * Sets up the variable and fixed fbdev metainformation from the given fb helper
2010 * instance and the drm framebuffer allocated in &drm_fb_helper.fb.
2012 * Drivers should call this (or their equivalent setup code) from their
2013 * &drm_fb_helper_funcs.fb_probe callback after having allocated the fbdev
2014 * backing storage framebuffer.
2016 void drm_fb_helper_fill_info(struct fb_info *info,
2017 struct drm_fb_helper *fb_helper,
2018 struct drm_fb_helper_surface_size *sizes)
2020 struct drm_framebuffer *fb = fb_helper->fb;
2022 drm_fb_helper_fill_fix(info, fb->pitches[0],
2023 fb->format->is_color_indexed);
2024 drm_fb_helper_fill_var(info, fb_helper,
2025 sizes->fb_width, sizes->fb_height);
2027 info->par = fb_helper;
2029 * The DRM drivers fbdev emulation device name can be confusing if the
2030 * driver name also has a "drm" suffix on it. Leading to names such as
2031 * "simpledrmdrmfb" in /proc/fb. Unfortunately, it's an uAPI and can't
2032 * be changed due user-space tools (e.g: pm-utils) matching against it.
2034 snprintf(info->fix.id, sizeof(info->fix.id), "%sdrmfb",
2035 fb_helper->dev->driver->name);
2038 EXPORT_SYMBOL(drm_fb_helper_fill_info);
2041 * This is a continuation of drm_setup_crtcs() that sets up anything related
2042 * to the framebuffer. During initialization, drm_setup_crtcs() is called before
2043 * the framebuffer has been allocated (fb_helper->fb and fb_helper->info).
2044 * So, any setup that touches those fields needs to be done here instead of in
2045 * drm_setup_crtcs().
2047 static void drm_setup_crtcs_fb(struct drm_fb_helper *fb_helper)
2049 struct drm_client_dev *client = &fb_helper->client;
2050 struct drm_connector_list_iter conn_iter;
2051 struct fb_info *info = fb_helper->info;
2052 unsigned int rotation, sw_rotations = 0;
2053 struct drm_connector *connector;
2054 struct drm_mode_set *modeset;
2056 mutex_lock(&client->modeset_mutex);
2057 drm_client_for_each_modeset(modeset, client) {
2058 if (!modeset->num_connectors)
2061 modeset->fb = fb_helper->fb;
2063 if (drm_client_rotation(modeset, &rotation))
2064 /* Rotating in hardware, fbcon should not rotate */
2065 sw_rotations |= DRM_MODE_ROTATE_0;
2067 sw_rotations |= rotation;
2069 mutex_unlock(&client->modeset_mutex);
2071 drm_connector_list_iter_begin(fb_helper->dev, &conn_iter);
2072 drm_client_for_each_connector_iter(connector, &conn_iter) {
2074 /* use first connected connector for the physical dimensions */
2075 if (connector->status == connector_status_connected) {
2076 info->var.width = connector->display_info.width_mm;
2077 info->var.height = connector->display_info.height_mm;
2081 drm_connector_list_iter_end(&conn_iter);
2083 switch (sw_rotations) {
2084 case DRM_MODE_ROTATE_0:
2085 info->fbcon_rotate_hint = FB_ROTATE_UR;
2087 case DRM_MODE_ROTATE_90:
2088 info->fbcon_rotate_hint = FB_ROTATE_CCW;
2090 case DRM_MODE_ROTATE_180:
2091 info->fbcon_rotate_hint = FB_ROTATE_UD;
2093 case DRM_MODE_ROTATE_270:
2094 info->fbcon_rotate_hint = FB_ROTATE_CW;
2098 * Multiple bits are set / multiple rotations requested
2099 * fbcon cannot handle separate rotation settings per
2100 * output, so fallback to unrotated.
2102 info->fbcon_rotate_hint = FB_ROTATE_UR;
2106 /* Note: Drops fb_helper->lock before returning. */
2108 __drm_fb_helper_initial_config_and_unlock(struct drm_fb_helper *fb_helper,
2111 struct drm_device *dev = fb_helper->dev;
2112 struct fb_info *info;
2113 unsigned int width, height;
2116 width = dev->mode_config.max_width;
2117 height = dev->mode_config.max_height;
2119 drm_client_modeset_probe(&fb_helper->client, width, height);
2120 ret = drm_fb_helper_single_fb_probe(fb_helper, bpp_sel);
2122 if (ret == -EAGAIN) {
2123 fb_helper->preferred_bpp = bpp_sel;
2124 fb_helper->deferred_setup = true;
2127 mutex_unlock(&fb_helper->lock);
2131 drm_setup_crtcs_fb(fb_helper);
2133 fb_helper->deferred_setup = false;
2135 info = fb_helper->info;
2136 info->var.pixclock = 0;
2137 /* Shamelessly allow physical address leaking to userspace */
2138 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
2139 if (!fb_helper->hint_leak_smem_start)
2141 /* don't leak any physical addresses to userspace */
2142 info->flags |= FBINFO_HIDE_SMEM_START;
2144 /* Need to drop locks to avoid recursive deadlock in
2145 * register_framebuffer. This is ok because the only thing left to do is
2146 * register the fbdev emulation instance in kernel_fb_helper_list. */
2147 mutex_unlock(&fb_helper->lock);
2149 ret = register_framebuffer(info);
2153 drm_info(dev, "fb%d: %s frame buffer device\n",
2154 info->node, info->fix.id);
2156 mutex_lock(&kernel_fb_helper_lock);
2157 if (list_empty(&kernel_fb_helper_list))
2158 register_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
2160 list_add(&fb_helper->kernel_fb_list, &kernel_fb_helper_list);
2161 mutex_unlock(&kernel_fb_helper_lock);
2167 * drm_fb_helper_initial_config - setup a sane initial connector configuration
2168 * @fb_helper: fb_helper device struct
2169 * @bpp_sel: bpp value to use for the framebuffer configuration
2171 * Scans the CRTCs and connectors and tries to put together an initial setup.
2172 * At the moment, this is a cloned configuration across all heads with
2173 * a new framebuffer object as the backing store.
2175 * Note that this also registers the fbdev and so allows userspace to call into
2176 * the driver through the fbdev interfaces.
2178 * This function will call down into the &drm_fb_helper_funcs.fb_probe callback
2179 * to let the driver allocate and initialize the fbdev info structure and the
2180 * drm framebuffer used to back the fbdev. drm_fb_helper_fill_info() is provided
2181 * as a helper to setup simple default values for the fbdev info structure.
2185 * When you have fbcon support built-in or already loaded, this function will do
2186 * a full modeset to setup the fbdev console. Due to locking misdesign in the
2187 * VT/fbdev subsystem that entire modeset sequence has to be done while holding
2188 * console_lock. Until console_unlock is called no dmesg lines will be sent out
2189 * to consoles, not even serial console. This means when your driver crashes,
2190 * you will see absolutely nothing else but a system stuck in this function,
2191 * with no further output. Any kind of printk() you place within your own driver
2192 * or in the drm core modeset code will also never show up.
2194 * Standard debug practice is to run the fbcon setup without taking the
2195 * console_lock as a hack, to be able to see backtraces and crashes on the
2196 * serial line. This can be done by setting the fb.lockless_register_fb=1 kernel
2199 * The other option is to just disable fbdev emulation since very likely the
2200 * first modeset from userspace will crash in the same way, and is even easier
2201 * to debug. This can be done by setting the drm_kms_helper.fbdev_emulation=0
2202 * kernel cmdline option.
2205 * Zero if everything went ok, nonzero otherwise.
2207 int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel)
2211 if (!drm_fbdev_emulation)
2214 mutex_lock(&fb_helper->lock);
2215 ret = __drm_fb_helper_initial_config_and_unlock(fb_helper, bpp_sel);
2219 EXPORT_SYMBOL(drm_fb_helper_initial_config);
2222 * drm_fb_helper_hotplug_event - respond to a hotplug notification by
2223 * probing all the outputs attached to the fb
2224 * @fb_helper: driver-allocated fbdev helper, can be NULL
2226 * Scan the connectors attached to the fb_helper and try to put together a
2227 * setup after notification of a change in output configuration.
2229 * Called at runtime, takes the mode config locks to be able to check/change the
2230 * modeset configuration. Must be run from process context (which usually means
2231 * either the output polling work or a work item launched from the driver's
2232 * hotplug interrupt).
2234 * Note that drivers may call this even before calling
2235 * drm_fb_helper_initial_config but only after drm_fb_helper_init. This allows
2236 * for a race-free fbcon setup and will make sure that the fbdev emulation will
2237 * not miss any hotplug events.
2240 * 0 on success and a non-zero error code otherwise.
2242 int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
2246 if (!drm_fbdev_emulation || !fb_helper)
2249 mutex_lock(&fb_helper->lock);
2250 if (fb_helper->deferred_setup) {
2251 err = __drm_fb_helper_initial_config_and_unlock(fb_helper,
2252 fb_helper->preferred_bpp);
2256 if (!fb_helper->fb || !drm_master_internal_acquire(fb_helper->dev)) {
2257 fb_helper->delayed_hotplug = true;
2258 mutex_unlock(&fb_helper->lock);
2262 drm_master_internal_release(fb_helper->dev);
2264 drm_dbg_kms(fb_helper->dev, "\n");
2266 drm_client_modeset_probe(&fb_helper->client, fb_helper->fb->width, fb_helper->fb->height);
2267 drm_setup_crtcs_fb(fb_helper);
2268 mutex_unlock(&fb_helper->lock);
2270 drm_fb_helper_set_par(fb_helper->info);
2274 EXPORT_SYMBOL(drm_fb_helper_hotplug_event);
2277 * drm_fb_helper_lastclose - DRM driver lastclose helper for fbdev emulation
2280 * This function can be used as the &drm_driver->lastclose callback for drivers
2281 * that only need to call drm_fb_helper_restore_fbdev_mode_unlocked().
2283 void drm_fb_helper_lastclose(struct drm_device *dev)
2285 drm_fb_helper_restore_fbdev_mode_unlocked(dev->fb_helper);
2287 EXPORT_SYMBOL(drm_fb_helper_lastclose);
2290 * drm_fb_helper_output_poll_changed - DRM mode config \.output_poll_changed
2291 * helper for fbdev emulation
2294 * This function can be used as the
2295 * &drm_mode_config_funcs.output_poll_changed callback for drivers that only
2296 * need to call drm_fbdev.hotplug_event().
2298 void drm_fb_helper_output_poll_changed(struct drm_device *dev)
2300 drm_fb_helper_hotplug_event(dev->fb_helper);
2302 EXPORT_SYMBOL(drm_fb_helper_output_poll_changed);