root/drivers/gpu/drm/drm_fb_helper.c

DEFINITIONS

1. drm_fb_helper_restore_lut_atomic
2. drm_fb_helper_debug_enter
3. drm_fb_helper_debug_leave
4. drm_fb_helper_restore_fbdev_mode_unlocked
5. drm_fb_helper_force_kernel_mode
6. drm_fb_helper_restore_work_fn
7. drm_fb_helper_sysrq
8. drm_fb_helper_dpms
9. drm_fb_helper_blank
10. drm_fb_helper_resume_worker
11. drm_fb_helper_dirty_blit_real
12. drm_fb_helper_dirty_work
13. drm_fb_helper_prepare
14. drm_fb_helper_init
15. drm_fb_helper_alloc_fbi
16. drm_fb_helper_unregister_fbi
17. drm_fb_helper_fini
18. drm_fb_helper_unlink_fbi
19. drm_fbdev_use_shadow_fb
20. drm_fb_helper_dirty
21. drm_fb_helper_deferred_io
22. drm_fb_helper_defio_init
23. drm_fb_helper_sys_read
24. drm_fb_helper_sys_write
25. drm_fb_helper_sys_fillrect
26. drm_fb_helper_sys_copyarea
27. drm_fb_helper_sys_imageblit
28. drm_fb_helper_cfb_fillrect
29. drm_fb_helper_cfb_copyarea
30. drm_fb_helper_cfb_imageblit
31. drm_fb_helper_set_suspend
32. drm_fb_helper_set_suspend_unlocked
33. setcmap_pseudo_palette
34. setcmap_legacy
35. setcmap_new_gamma_lut
36. setcmap_atomic
37. drm_fb_helper_setcmap
38. drm_fb_helper_ioctl
39. drm_fb_pixel_format_equal
40. drm_fb_helper_fill_pixel_fmt
41. drm_fb_helper_check_var
42. drm_fb_helper_set_par
43. pan_set
44. pan_display_atomic
45. pan_display_legacy
46. drm_fb_helper_pan_display
47. drm_fb_helper_single_fb_probe
48. drm_fb_helper_fill_fix
49. drm_fb_helper_fill_var
50. drm_fb_helper_fill_info
51. drm_setup_crtcs_fb
52. __drm_fb_helper_initial_config_and_unlock
53. drm_fb_helper_initial_config
54. drm_fb_helper_hotplug_event
55. drm_fb_helper_fbdev_setup
56. drm_fb_helper_fbdev_teardown
57. drm_fb_helper_lastclose
58. drm_fb_helper_output_poll_changed
59. drm_fbdev_fb_open
60. drm_fbdev_fb_release
61. drm_fbdev_cleanup
62. drm_fbdev_release
63. drm_fbdev_fb_destroy
64. drm_fbdev_fb_mmap
65. drm_fb_helper_generic_probe
66. drm_fbdev_client_unregister
67. drm_fbdev_client_restore
68. drm_fbdev_client_hotplug
69. drm_fbdev_generic_setup
70. drm_fb_helper_modinit

   1 /*
   2  * Copyright (c) 2006-2009 Red Hat Inc.
   3  * Copyright (c) 2006-2008 Intel Corporation
   4  * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
   5  *
   6  * DRM framebuffer helper functions
   7  *
   8  * Permission to use, copy, modify, distribute, and sell this software and its
   9  * documentation for any purpose is hereby granted without fee, provided that
  10  * the above copyright notice appear in all copies and that both that copyright
  11  * notice and this permission notice appear in supporting documentation, and
  12  * that the name of the copyright holders not be used in advertising or
  13  * publicity pertaining to distribution of the software without specific,
  14  * written prior permission.  The copyright holders make no representations
  15  * about the suitability of this software for any purpose.  It is provided "as
  16  * is" without express or implied warranty.
  17  *
  18  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  19  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  20  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  21  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  22  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  23  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  24  * OF THIS SOFTWARE.
  25  *
  26  * Authors:
  27  *      Dave Airlie <airlied@linux.ie>
  28  *      Jesse Barnes <jesse.barnes@intel.com>
  29  */
  30 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  31 
  32 #include <linux/console.h>
  33 #include <linux/dma-buf.h>
  34 #include <linux/kernel.h>
  35 #include <linux/module.h>
  36 #include <linux/slab.h>
  37 #include <linux/sysrq.h>
  38 #include <linux/vmalloc.h>
  39 
  40 #include <drm/drm_atomic.h>
  41 #include <drm/drm_crtc.h>
  42 #include <drm/drm_crtc_helper.h>
  43 #include <drm/drm_drv.h>
  44 #include <drm/drm_fb_helper.h>
  45 #include <drm/drm_fourcc.h>
  46 #include <drm/drm_print.h>
  47 #include <drm/drm_vblank.h>
  48 
  49 #include "drm_internal.h"
  50 
  51 static bool drm_fbdev_emulation = true;
  52 module_param_named(fbdev_emulation, drm_fbdev_emulation, bool, 0600);
  53 MODULE_PARM_DESC(fbdev_emulation,
  54                  "Enable legacy fbdev emulation [default=true]");
  55 
  56 static int drm_fbdev_overalloc = CONFIG_DRM_FBDEV_OVERALLOC;
  57 module_param(drm_fbdev_overalloc, int, 0444);
  58 MODULE_PARM_DESC(drm_fbdev_overalloc,
  59                  "Overallocation of the fbdev buffer (%) [default="
  60                  __MODULE_STRING(CONFIG_DRM_FBDEV_OVERALLOC) "]");
  61 
  62 /*
  63  * In order to keep user-space compatibility, we want in certain use-cases
  64  * to keep leaking the fbdev physical address to the user-space program
  65  * handling the fbdev buffer.
  66  * This is a bad habit essentially kept into closed source opengl driver
  67  * that should really be moved into open-source upstream projects instead
  68  * of using legacy physical addresses in user space to communicate with
  69  * other out-of-tree kernel modules.
  70  *
  71  * This module_param *should* be removed as soon as possible and be
  72  * considered as a broken and legacy behaviour from a modern fbdev device.
  73  */
  74 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
  75 static bool drm_leak_fbdev_smem = false;
  76 module_param_unsafe(drm_leak_fbdev_smem, bool, 0600);
  77 MODULE_PARM_DESC(drm_leak_fbdev_smem,
  78                  "Allow unsafe leaking fbdev physical smem address [default=false]");
  79 #endif
  80 
  81 static LIST_HEAD(kernel_fb_helper_list);
  82 static DEFINE_MUTEX(kernel_fb_helper_lock);
  83 
  84 /**
  85  * DOC: fbdev helpers
  86  *
  87  * The fb helper functions are useful to provide an fbdev on top of a drm kernel
  88  * mode setting driver. They can be used mostly independently from the crtc
  89  * helper functions used by many drivers to implement the kernel mode setting
  90  * interfaces.
  91  *
  92  * Drivers that support a dumb buffer with a virtual address and mmap support,
  93  * should try out the generic fbdev emulation using drm_fbdev_generic_setup().
  94  *
  95  * Setup fbdev emulation by calling drm_fb_helper_fbdev_setup() and tear it
  96  * down by calling drm_fb_helper_fbdev_teardown().
  97  *
  98  * At runtime drivers should restore the fbdev console by using
  99  * drm_fb_helper_lastclose() as their &drm_driver.lastclose callback.
 100  * They should also notify the fb helper code from updates to the output
 101  * configuration by using drm_fb_helper_output_poll_changed() as their
 102  * &drm_mode_config_funcs.output_poll_changed callback.
 103  *
 104  * For suspend/resume consider using drm_mode_config_helper_suspend() and
 105  * drm_mode_config_helper_resume() which takes care of fbdev as well.
 106  *
 107  * All other functions exported by the fb helper library can be used to
 108  * implement the fbdev driver interface by the driver.
 109  *
 110  * It is possible, though perhaps somewhat tricky, to implement race-free
 111  * hotplug detection using the fbdev helpers. The drm_fb_helper_prepare()
 112  * helper must be called first to initialize the minimum required to make
 113  * hotplug detection work. Drivers also need to make sure to properly set up
 114  * the &drm_mode_config.funcs member. After calling drm_kms_helper_poll_init()
 115  * it is safe to enable interrupts and start processing hotplug events. At the
 116  * same time, drivers should initialize all modeset objects such as CRTCs,
 117  * encoders and connectors. To finish up the fbdev helper initialization, the
 118  * drm_fb_helper_init() function is called. To probe for all attached displays
 119  * and set up an initial configuration using the detected hardware, drivers
 120  * should call drm_fb_helper_initial_config().
 121  *
 122  * If &drm_framebuffer_funcs.dirty is set, the
 123  * drm_fb_helper_{cfb,sys}_{write,fillrect,copyarea,imageblit} functions will
 124  * accumulate changes and schedule &drm_fb_helper.dirty_work to run right
 125  * away. This worker then calls the dirty() function ensuring that it will
 126  * always run in process context since the fb_*() function could be running in
 127  * atomic context. If drm_fb_helper_deferred_io() is used as the deferred_io
 128  * callback it will also schedule dirty_work with the damage collected from the
 129  * mmap page writes. Drivers can use drm_fb_helper_defio_init() to setup
 130  * deferred I/O (coupled with drm_fb_helper_fbdev_teardown()).
 131  */
 132 
 133 static void drm_fb_helper_restore_lut_atomic(struct drm_crtc *crtc)
 134 {
 135         uint16_t *r_base, *g_base, *b_base;
 136 
 137         if (crtc->funcs->gamma_set == NULL)
 138                 return;
 139 
 140         r_base = crtc->gamma_store;
 141         g_base = r_base + crtc->gamma_size;
 142         b_base = g_base + crtc->gamma_size;
 143 
 144         crtc->funcs->gamma_set(crtc, r_base, g_base, b_base,
 145                                crtc->gamma_size, NULL);
 146 }
 147 
 148 /**
 149  * drm_fb_helper_debug_enter - implementation for &fb_ops.fb_debug_enter
 150  * @info: fbdev registered by the helper
 151  */
 152 int drm_fb_helper_debug_enter(struct fb_info *info)
 153 {
 154         struct drm_fb_helper *helper = info->par;
 155         const struct drm_crtc_helper_funcs *funcs;
 156         struct drm_mode_set *mode_set;
 157 
 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)
 162                                 continue;
 163 
 164                         funcs = mode_set->crtc->helper_private;
 165                         if (funcs->mode_set_base_atomic == NULL)
 166                                 continue;
 167 
 168                         if (drm_drv_uses_atomic_modeset(mode_set->crtc->dev))
 169                                 continue;
 170 
 171                         funcs->mode_set_base_atomic(mode_set->crtc,
 172                                                     mode_set->fb,
 173                                                     mode_set->x,
 174                                                     mode_set->y,
 175                                                     ENTER_ATOMIC_MODE_SET);
 176                 }
 177                 mutex_unlock(&helper->client.modeset_mutex);
 178         }
 179 
 180         return 0;
 181 }
 182 EXPORT_SYMBOL(drm_fb_helper_debug_enter);
 183 
 184 /**
 185  * drm_fb_helper_debug_leave - implementation for &fb_ops.fb_debug_leave
 186  * @info: fbdev registered by the helper
 187  */
 188 int drm_fb_helper_debug_leave(struct fb_info *info)
 189 {
 190         struct drm_fb_helper *helper = info->par;
 191         struct drm_client_dev *client = &helper->client;
 192         struct drm_crtc *crtc;
 193         const struct drm_crtc_helper_funcs *funcs;
 194         struct drm_mode_set *mode_set;
 195         struct drm_framebuffer *fb;
 196 
 197         mutex_lock(&client->modeset_mutex);
 198         drm_client_for_each_modeset(mode_set, client) {
 199                 crtc = mode_set->crtc;
 200                 if (drm_drv_uses_atomic_modeset(crtc->dev))
 201                         continue;
 202 
 203                 funcs = crtc->helper_private;
 204                 fb = crtc->primary->fb;
 205 
 206                 if (!crtc->enabled)
 207                         continue;
 208 
 209                 if (!fb) {
 210                         DRM_ERROR("no fb to restore??\n");
 211                         continue;
 212                 }
 213 
 214                 if (funcs->mode_set_base_atomic == NULL)
 215                         continue;
 216 
 217                 drm_fb_helper_restore_lut_atomic(mode_set->crtc);
 218                 funcs->mode_set_base_atomic(mode_set->crtc, fb, crtc->x,
 219                                             crtc->y, LEAVE_ATOMIC_MODE_SET);
 220         }
 221         mutex_unlock(&client->modeset_mutex);
 222 
 223         return 0;
 224 }
 225 EXPORT_SYMBOL(drm_fb_helper_debug_leave);
 226 
 227 /**
 228  * drm_fb_helper_restore_fbdev_mode_unlocked - restore fbdev configuration
 229  * @fb_helper: driver-allocated fbdev helper, can be NULL
 230  *
 231  * This should be called from driver's drm &drm_driver.lastclose callback
 232  * when implementing an fbcon on top of kms using this helper. This ensures that
 233  * the user isn't greeted with a black screen when e.g. X dies.
 234  *
 235  * RETURNS:
 236  * Zero if everything went ok, negative error code otherwise.
 237  */
 238 int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
 239 {
 240         bool do_delayed;
 241         int ret;
 242 
 243         if (!drm_fbdev_emulation || !fb_helper)
 244                 return -ENODEV;
 245 
 246         if (READ_ONCE(fb_helper->deferred_setup))
 247                 return 0;
 248 
 249         mutex_lock(&fb_helper->lock);
 250         /*
 251          * TODO:
 252          * We should bail out here if there is a master by dropping _force.
 253          * Currently these igt tests fail if we do that:
 254          * - kms_fbcon_fbt@psr
 255          * - kms_fbcon_fbt@psr-suspend
 256          *
 257          * So first these tests need to be fixed so they drop master or don't
 258          * have an fd open.
 259          */
 260         ret = drm_client_modeset_commit_force(&fb_helper->client);
 261 
 262         do_delayed = fb_helper->delayed_hotplug;
 263         if (do_delayed)
 264                 fb_helper->delayed_hotplug = false;
 265         mutex_unlock(&fb_helper->lock);
 266 
 267         if (do_delayed)
 268                 drm_fb_helper_hotplug_event(fb_helper);
 269 
 270         return ret;
 271 }
 272 EXPORT_SYMBOL(drm_fb_helper_restore_fbdev_mode_unlocked);
 273 
 274 #ifdef CONFIG_MAGIC_SYSRQ
 275 /*
 276  * restore fbcon display for all kms driver's using this helper, used for sysrq
 277  * and panic handling.
 278  */
 279 static bool drm_fb_helper_force_kernel_mode(void)
 280 {
 281         bool ret, error = false;
 282         struct drm_fb_helper *helper;
 283 
 284         if (list_empty(&kernel_fb_helper_list))
 285                 return false;
 286 
 287         list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
 288                 struct drm_device *dev = helper->dev;
 289 
 290                 if (dev->switch_power_state == DRM_SWITCH_POWER_OFF)
 291                         continue;
 292 
 293                 mutex_lock(&helper->lock);
 294                 ret = drm_client_modeset_commit_force(&helper->client);
 295                 if (ret)
 296                         error = true;
 297                 mutex_unlock(&helper->lock);
 298         }
 299         return error;
 300 }
 301 
 302 static void drm_fb_helper_restore_work_fn(struct work_struct *ignored)
 303 {
 304         bool ret;
 305 
 306         ret = drm_fb_helper_force_kernel_mode();
 307         if (ret == true)
 308                 DRM_ERROR("Failed to restore crtc configuration\n");
 309 }
 310 static DECLARE_WORK(drm_fb_helper_restore_work, drm_fb_helper_restore_work_fn);
 311 
 312 static void drm_fb_helper_sysrq(int dummy1)
 313 {
 314         schedule_work(&drm_fb_helper_restore_work);
 315 }
 316 
 317 static struct sysrq_key_op sysrq_drm_fb_helper_restore_op = {
 318         .handler = drm_fb_helper_sysrq,
 319         .help_msg = "force-fb(V)",
 320         .action_msg = "Restore framebuffer console",
 321 };
 322 #else
 323 static struct sysrq_key_op sysrq_drm_fb_helper_restore_op = { };
 324 #endif
 325 
 326 static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode)
 327 {
 328         struct drm_fb_helper *fb_helper = info->par;
 329 
 330         mutex_lock(&fb_helper->lock);
 331         drm_client_modeset_dpms(&fb_helper->client, dpms_mode);
 332         mutex_unlock(&fb_helper->lock);
 333 }
 334 
 335 /**
 336  * drm_fb_helper_blank - implementation for &fb_ops.fb_blank
 337  * @blank: desired blanking state
 338  * @info: fbdev registered by the helper
 339  */
 340 int drm_fb_helper_blank(int blank, struct fb_info *info)
 341 {
 342         if (oops_in_progress)
 343                 return -EBUSY;
 344 
 345         switch (blank) {
 346         /* Display: On; HSync: On, VSync: On */
 347         case FB_BLANK_UNBLANK:
 348                 drm_fb_helper_dpms(info, DRM_MODE_DPMS_ON);
 349                 break;
 350         /* Display: Off; HSync: On, VSync: On */
 351         case FB_BLANK_NORMAL:
 352                 drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
 353                 break;
 354         /* Display: Off; HSync: Off, VSync: On */
 355         case FB_BLANK_HSYNC_SUSPEND:
 356                 drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
 357                 break;
 358         /* Display: Off; HSync: On, VSync: Off */
 359         case FB_BLANK_VSYNC_SUSPEND:
 360                 drm_fb_helper_dpms(info, DRM_MODE_DPMS_SUSPEND);
 361                 break;
 362         /* Display: Off; HSync: Off, VSync: Off */
 363         case FB_BLANK_POWERDOWN:
 364                 drm_fb_helper_dpms(info, DRM_MODE_DPMS_OFF);
 365                 break;
 366         }
 367         return 0;
 368 }
 369 EXPORT_SYMBOL(drm_fb_helper_blank);
 370 
 371 static void drm_fb_helper_resume_worker(struct work_struct *work)
 372 {
 373         struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper,
 374                                                     resume_work);
 375 
 376         console_lock();
 377         fb_set_suspend(helper->fbdev, 0);
 378         console_unlock();
 379 }
 380 
 381 static void drm_fb_helper_dirty_blit_real(struct drm_fb_helper *fb_helper,
 382                                           struct drm_clip_rect *clip)
 383 {
 384         struct drm_framebuffer *fb = fb_helper->fb;
 385         unsigned int cpp = fb->format->cpp[0];
 386         size_t offset = clip->y1 * fb->pitches[0] + clip->x1 * cpp;
 387         void *src = fb_helper->fbdev->screen_buffer + offset;
 388         void *dst = fb_helper->buffer->vaddr + offset;
 389         size_t len = (clip->x2 - clip->x1) * cpp;
 390         unsigned int y;
 391 
 392         for (y = clip->y1; y < clip->y2; y++) {
 393                 memcpy(dst, src, len);
 394                 src += fb->pitches[0];
 395                 dst += fb->pitches[0];
 396         }
 397 }
 398 
 399 static void drm_fb_helper_dirty_work(struct work_struct *work)
 400 {
 401         struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper,
 402                                                     dirty_work);
 403         struct drm_clip_rect *clip = &helper->dirty_clip;
 404         struct drm_clip_rect clip_copy;
 405         unsigned long flags;
 406         void *vaddr;
 407 
 408         spin_lock_irqsave(&helper->dirty_lock, flags);
 409         clip_copy = *clip;
 410         clip->x1 = clip->y1 = ~0;
 411         clip->x2 = clip->y2 = 0;
 412         spin_unlock_irqrestore(&helper->dirty_lock, flags);
 413 
 414         /* call dirty callback only when it has been really touched */
 415         if (clip_copy.x1 < clip_copy.x2 && clip_copy.y1 < clip_copy.y2) {
 416 
 417                 /* Generic fbdev uses a shadow buffer */
 418                 if (helper->buffer) {
 419                         vaddr = drm_client_buffer_vmap(helper->buffer);
 420                         if (IS_ERR(vaddr))
 421                                 return;
 422                         drm_fb_helper_dirty_blit_real(helper, &clip_copy);
 423                 }
 424                 if (helper->fb->funcs->dirty)
 425                         helper->fb->funcs->dirty(helper->fb, NULL, 0, 0,
 426                                                  &clip_copy, 1);
 427 
 428                 if (helper->buffer)
 429                         drm_client_buffer_vunmap(helper->buffer);
 430         }
 431 }
 432 
 433 /**
 434  * drm_fb_helper_prepare - setup a drm_fb_helper structure
 435  * @dev: DRM device
 436  * @helper: driver-allocated fbdev helper structure to set up
 437  * @funcs: pointer to structure of functions associate with this helper
 438  *
 439  * Sets up the bare minimum to make the framebuffer helper usable. This is
 440  * useful to implement race-free initialization of the polling helpers.
 441  */
 442 void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
 443                            const struct drm_fb_helper_funcs *funcs)
 444 {
 445         INIT_LIST_HEAD(&helper->kernel_fb_list);
 446         spin_lock_init(&helper->dirty_lock);
 447         INIT_WORK(&helper->resume_work, drm_fb_helper_resume_worker);
 448         INIT_WORK(&helper->dirty_work, drm_fb_helper_dirty_work);
 449         helper->dirty_clip.x1 = helper->dirty_clip.y1 = ~0;
 450         mutex_init(&helper->lock);
 451         helper->funcs = funcs;
 452         helper->dev = dev;
 453 }
 454 EXPORT_SYMBOL(drm_fb_helper_prepare);
 455 
 456 /**
 457  * drm_fb_helper_init - initialize a &struct drm_fb_helper
 458  * @dev: drm device
 459  * @fb_helper: driver-allocated fbdev helper structure to initialize
 460  * @max_conn_count: max connector count (not used)
 461  *
 462  * This allocates the structures for the fbdev helper with the given limits.
 463  * Note that this won't yet touch the hardware (through the driver interfaces)
 464  * nor register the fbdev. This is only done in drm_fb_helper_initial_config()
 465  * to allow driver writes more control over the exact init sequence.
 466  *
 467  * Drivers must call drm_fb_helper_prepare() before calling this function.
 468  *
 469  * RETURNS:
 470  * Zero if everything went ok, nonzero otherwise.
 471  */
 472 int drm_fb_helper_init(struct drm_device *dev,
 473                        struct drm_fb_helper *fb_helper,
 474                        int max_conn_count)
 475 {
 476         int ret;
 477 
 478         if (!drm_fbdev_emulation) {
 479                 dev->fb_helper = fb_helper;
 480                 return 0;
 481         }
 482 
 483         /*
 484          * If this is not the generic fbdev client, initialize a drm_client
 485          * without callbacks so we can use the modesets.
 486          */
 487         if (!fb_helper->client.funcs) {
 488                 ret = drm_client_init(dev, &fb_helper->client, "drm_fb_helper", NULL);
 489                 if (ret)
 490                         return ret;
 491         }
 492 
 493         dev->fb_helper = fb_helper;
 494 
 495         return 0;
 496 }
 497 EXPORT_SYMBOL(drm_fb_helper_init);
 498 
 499 /**
 500  * drm_fb_helper_alloc_fbi - allocate fb_info and some of its members
 501  * @fb_helper: driver-allocated fbdev helper
 502  *
 503  * A helper to alloc fb_info and the members cmap and apertures. Called
 504  * by the driver within the fb_probe fb_helper callback function. Drivers do not
 505  * need to release the allocated fb_info structure themselves, this is
 506  * automatically done when calling drm_fb_helper_fini().
 507  *
 508  * RETURNS:
 509  * fb_info pointer if things went okay, pointer containing error code
 510  * otherwise
 511  */
 512 struct fb_info *drm_fb_helper_alloc_fbi(struct drm_fb_helper *fb_helper)
 513 {
 514         struct device *dev = fb_helper->dev->dev;
 515         struct fb_info *info;
 516         int ret;
 517 
 518         info = framebuffer_alloc(0, dev);
 519         if (!info)
 520                 return ERR_PTR(-ENOMEM);
 521 
 522         ret = fb_alloc_cmap(&info->cmap, 256, 0);
 523         if (ret)
 524                 goto err_release;
 525 
 526         info->apertures = alloc_apertures(1);
 527         if (!info->apertures) {
 528                 ret = -ENOMEM;
 529                 goto err_free_cmap;
 530         }
 531 
 532         fb_helper->fbdev = info;
 533         info->skip_vt_switch = true;
 534 
 535         return info;
 536 
 537 err_free_cmap:
 538         fb_dealloc_cmap(&info->cmap);
 539 err_release:
 540         framebuffer_release(info);
 541         return ERR_PTR(ret);
 542 }
 543 EXPORT_SYMBOL(drm_fb_helper_alloc_fbi);
 544 
 545 /**
 546  * drm_fb_helper_unregister_fbi - unregister fb_info framebuffer device
 547  * @fb_helper: driver-allocated fbdev helper, can be NULL
 548  *
 549  * A wrapper around unregister_framebuffer, to release the fb_info
 550  * framebuffer device. This must be called before releasing all resources for
 551  * @fb_helper by calling drm_fb_helper_fini().
 552  */
 553 void drm_fb_helper_unregister_fbi(struct drm_fb_helper *fb_helper)
 554 {
 555         if (fb_helper && fb_helper->fbdev)
 556                 unregister_framebuffer(fb_helper->fbdev);
 557 }
 558 EXPORT_SYMBOL(drm_fb_helper_unregister_fbi);
 559 
 560 /**
 561  * drm_fb_helper_fini - finialize a &struct drm_fb_helper
 562  * @fb_helper: driver-allocated fbdev helper, can be NULL
 563  *
 564  * This cleans up all remaining resources associated with @fb_helper. Must be
 565  * called after drm_fb_helper_unlink_fbi() was called.
 566  */
 567 void drm_fb_helper_fini(struct drm_fb_helper *fb_helper)
 568 {
 569         struct fb_info *info;
 570 
 571         if (!fb_helper)
 572                 return;
 573 
 574         fb_helper->dev->fb_helper = NULL;
 575 
 576         if (!drm_fbdev_emulation)
 577                 return;
 578 
 579         cancel_work_sync(&fb_helper->resume_work);
 580         cancel_work_sync(&fb_helper->dirty_work);
 581 
 582         info = fb_helper->fbdev;
 583         if (info) {
 584                 if (info->cmap.len)
 585                         fb_dealloc_cmap(&info->cmap);
 586                 framebuffer_release(info);
 587         }
 588         fb_helper->fbdev = NULL;
 589 
 590         mutex_lock(&kernel_fb_helper_lock);
 591         if (!list_empty(&fb_helper->kernel_fb_list)) {
 592                 list_del(&fb_helper->kernel_fb_list);
 593                 if (list_empty(&kernel_fb_helper_list))
 594                         unregister_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
 595         }
 596         mutex_unlock(&kernel_fb_helper_lock);
 597 
 598         mutex_destroy(&fb_helper->lock);
 599 
 600         if (!fb_helper->client.funcs)
 601                 drm_client_release(&fb_helper->client);
 602 }
 603 EXPORT_SYMBOL(drm_fb_helper_fini);
 604 
 605 /**
 606  * drm_fb_helper_unlink_fbi - wrapper around unlink_framebuffer
 607  * @fb_helper: driver-allocated fbdev helper, can be NULL
 608  *
 609  * A wrapper around unlink_framebuffer implemented by fbdev core
 610  */
 611 void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper)
 612 {
 613         if (fb_helper && fb_helper->fbdev)
 614                 unlink_framebuffer(fb_helper->fbdev);
 615 }
 616 EXPORT_SYMBOL(drm_fb_helper_unlink_fbi);
 617 
 618 static bool drm_fbdev_use_shadow_fb(struct drm_fb_helper *fb_helper)
 619 {
 620         struct drm_device *dev = fb_helper->dev;
 621         struct drm_framebuffer *fb = fb_helper->fb;
 622 
 623         return dev->mode_config.prefer_shadow_fbdev ||
 624                dev->mode_config.prefer_shadow ||
 625                fb->funcs->dirty;
 626 }
 627 
 628 static void drm_fb_helper_dirty(struct fb_info *info, u32 x, u32 y,
 629                                 u32 width, u32 height)
 630 {
 631         struct drm_fb_helper *helper = info->par;
 632         struct drm_clip_rect *clip = &helper->dirty_clip;
 633         unsigned long flags;
 634 
 635         if (!drm_fbdev_use_shadow_fb(helper))
 636                 return;
 637 
 638         spin_lock_irqsave(&helper->dirty_lock, flags);
 639         clip->x1 = min_t(u32, clip->x1, x);
 640         clip->y1 = min_t(u32, clip->y1, y);
 641         clip->x2 = max_t(u32, clip->x2, x + width);
 642         clip->y2 = max_t(u32, clip->y2, y + height);
 643         spin_unlock_irqrestore(&helper->dirty_lock, flags);
 644 
 645         schedule_work(&helper->dirty_work);
 646 }
 647 
 648 /**
 649  * drm_fb_helper_deferred_io() - fbdev deferred_io callback function
 650  * @info: fb_info struct pointer
 651  * @pagelist: list of dirty mmap framebuffer pages
 652  *
 653  * This function is used as the &fb_deferred_io.deferred_io
 654  * callback function for flushing the fbdev mmap writes.
 655  */
 656 void drm_fb_helper_deferred_io(struct fb_info *info,
 657                                struct list_head *pagelist)
 658 {
 659         unsigned long start, end, min, max;
 660         struct page *page;
 661         u32 y1, y2;
 662 
 663         min = ULONG_MAX;
 664         max = 0;
 665         list_for_each_entry(page, pagelist, lru) {
 666                 start = page->index << PAGE_SHIFT;
 667                 end = start + PAGE_SIZE - 1;
 668                 min = min(min, start);
 669                 max = max(max, end);
 670         }
 671 
 672         if (min < max) {
 673                 y1 = min / info->fix.line_length;
 674                 y2 = min_t(u32, DIV_ROUND_UP(max, info->fix.line_length),
 675                            info->var.yres);
 676                 drm_fb_helper_dirty(info, 0, y1, info->var.xres, y2 - y1);
 677         }
 678 }
 679 EXPORT_SYMBOL(drm_fb_helper_deferred_io);
 680 
 681 /**
 682  * drm_fb_helper_defio_init - fbdev deferred I/O initialization
 683  * @fb_helper: driver-allocated fbdev helper
 684  *
 685  * This function allocates &fb_deferred_io, sets callback to
 686  * drm_fb_helper_deferred_io(), delay to 50ms and calls fb_deferred_io_init().
 687  * It should be called from the &drm_fb_helper_funcs->fb_probe callback.
 688  * drm_fb_helper_fbdev_teardown() cleans up deferred I/O.
 689  *
 690  * NOTE: A copy of &fb_ops is made and assigned to &info->fbops. This is done
 691  * because fb_deferred_io_cleanup() clears &fbops->fb_mmap and would thereby
 692  * affect other instances of that &fb_ops.
 693  *
 694  * Returns:
 695  * 0 on success or a negative error code on failure.
 696  */
 697 int drm_fb_helper_defio_init(struct drm_fb_helper *fb_helper)
 698 {
 699         struct fb_info *info = fb_helper->fbdev;
 700         struct fb_deferred_io *fbdefio;
 701         struct fb_ops *fbops;
 702 
 703         fbdefio = kzalloc(sizeof(*fbdefio), GFP_KERNEL);
 704         fbops = kzalloc(sizeof(*fbops), GFP_KERNEL);
 705         if (!fbdefio || !fbops) {
 706                 kfree(fbdefio);
 707                 kfree(fbops);
 708                 return -ENOMEM;
 709         }
 710 
 711         info->fbdefio = fbdefio;
 712         fbdefio->delay = msecs_to_jiffies(50);
 713         fbdefio->deferred_io = drm_fb_helper_deferred_io;
 714 
 715         *fbops = *info->fbops;
 716         info->fbops = fbops;
 717 
 718         fb_deferred_io_init(info);
 719 
 720         return 0;
 721 }
 722 EXPORT_SYMBOL(drm_fb_helper_defio_init);
 723 
 724 /**
 725  * drm_fb_helper_sys_read - wrapper around fb_sys_read
 726  * @info: fb_info struct pointer
 727  * @buf: userspace buffer to read from framebuffer memory
 728  * @count: number of bytes to read from framebuffer memory
 729  * @ppos: read offset within framebuffer memory
 730  *
 731  * A wrapper around fb_sys_read implemented by fbdev core
 732  */
 733 ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
 734                                size_t count, loff_t *ppos)
 735 {
 736         return fb_sys_read(info, buf, count, ppos);
 737 }
 738 EXPORT_SYMBOL(drm_fb_helper_sys_read);
 739 
 740 /**
 741  * drm_fb_helper_sys_write - wrapper around fb_sys_write
 742  * @info: fb_info struct pointer
 743  * @buf: userspace buffer to write to framebuffer memory
 744  * @count: number of bytes to write to framebuffer memory
 745  * @ppos: write offset within framebuffer memory
 746  *
 747  * A wrapper around fb_sys_write implemented by fbdev core
 748  */
 749 ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
 750                                 size_t count, loff_t *ppos)
 751 {
 752         ssize_t ret;
 753 
 754         ret = fb_sys_write(info, buf, count, ppos);
 755         if (ret > 0)
 756                 drm_fb_helper_dirty(info, 0, 0, info->var.xres,
 757                                     info->var.yres);
 758 
 759         return ret;
 760 }
 761 EXPORT_SYMBOL(drm_fb_helper_sys_write);
 762 
 763 /**
 764  * drm_fb_helper_sys_fillrect - wrapper around sys_fillrect
 765  * @info: fbdev registered by the helper
 766  * @rect: info about rectangle to fill
 767  *
 768  * A wrapper around sys_fillrect implemented by fbdev core
 769  */
 770 void drm_fb_helper_sys_fillrect(struct fb_info *info,
 771                                 const struct fb_fillrect *rect)
 772 {
 773         sys_fillrect(info, rect);
 774         drm_fb_helper_dirty(info, rect->dx, rect->dy,
 775                             rect->width, rect->height);
 776 }
 777 EXPORT_SYMBOL(drm_fb_helper_sys_fillrect);
 778 
 779 /**
 780  * drm_fb_helper_sys_copyarea - wrapper around sys_copyarea
 781  * @info: fbdev registered by the helper
 782  * @area: info about area to copy
 783  *
 784  * A wrapper around sys_copyarea implemented by fbdev core
 785  */
 786 void drm_fb_helper_sys_copyarea(struct fb_info *info,
 787                                 const struct fb_copyarea *area)
 788 {
 789         sys_copyarea(info, area);
 790         drm_fb_helper_dirty(info, area->dx, area->dy,
 791                             area->width, area->height);
 792 }
 793 EXPORT_SYMBOL(drm_fb_helper_sys_copyarea);
 794 
 795 /**
 796  * drm_fb_helper_sys_imageblit - wrapper around sys_imageblit
 797  * @info: fbdev registered by the helper
 798  * @image: info about image to blit
 799  *
 800  * A wrapper around sys_imageblit implemented by fbdev core
 801  */
 802 void drm_fb_helper_sys_imageblit(struct fb_info *info,
 803                                  const struct fb_image *image)
 804 {
 805         sys_imageblit(info, image);
 806         drm_fb_helper_dirty(info, image->dx, image->dy,
 807                             image->width, image->height);
 808 }
 809 EXPORT_SYMBOL(drm_fb_helper_sys_imageblit);
 810 
 811 /**
 812  * drm_fb_helper_cfb_fillrect - wrapper around cfb_fillrect
 813  * @info: fbdev registered by the helper
 814  * @rect: info about rectangle to fill
 815  *
 816  * A wrapper around cfb_fillrect implemented by fbdev core
 817  */
 818 void drm_fb_helper_cfb_fillrect(struct fb_info *info,
 819                                 const struct fb_fillrect *rect)
 820 {
 821         cfb_fillrect(info, rect);
 822         drm_fb_helper_dirty(info, rect->dx, rect->dy,
 823                             rect->width, rect->height);
 824 }
 825 EXPORT_SYMBOL(drm_fb_helper_cfb_fillrect);
 826 
 827 /**
 828  * drm_fb_helper_cfb_copyarea - wrapper around cfb_copyarea
 829  * @info: fbdev registered by the helper
 830  * @area: info about area to copy
 831  *
 832  * A wrapper around cfb_copyarea implemented by fbdev core
 833  */
 834 void drm_fb_helper_cfb_copyarea(struct fb_info *info,
 835                                 const struct fb_copyarea *area)
 836 {
 837         cfb_copyarea(info, area);
 838         drm_fb_helper_dirty(info, area->dx, area->dy,
 839                             area->width, area->height);
 840 }
 841 EXPORT_SYMBOL(drm_fb_helper_cfb_copyarea);
 842 
 843 /**
 844  * drm_fb_helper_cfb_imageblit - wrapper around cfb_imageblit
 845  * @info: fbdev registered by the helper
 846  * @image: info about image to blit
 847  *
 848  * A wrapper around cfb_imageblit implemented by fbdev core
 849  */
 850 void drm_fb_helper_cfb_imageblit(struct fb_info *info,
 851                                  const struct fb_image *image)
 852 {
 853         cfb_imageblit(info, image);
 854         drm_fb_helper_dirty(info, image->dx, image->dy,
 855                             image->width, image->height);
 856 }
 857 EXPORT_SYMBOL(drm_fb_helper_cfb_imageblit);
 858 
 859 /**
 860  * drm_fb_helper_set_suspend - wrapper around fb_set_suspend
 861  * @fb_helper: driver-allocated fbdev helper, can be NULL
 862  * @suspend: whether to suspend or resume
 863  *
 864  * A wrapper around fb_set_suspend implemented by fbdev core.
 865  * Use drm_fb_helper_set_suspend_unlocked() if you don't need to take
 866  * the lock yourself
 867  */
 868 void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend)
 869 {
 870         if (fb_helper && fb_helper->fbdev)
 871                 fb_set_suspend(fb_helper->fbdev, suspend);
 872 }
 873 EXPORT_SYMBOL(drm_fb_helper_set_suspend);
 874 
 875 /**
 876  * drm_fb_helper_set_suspend_unlocked - wrapper around fb_set_suspend that also
 877  *                                      takes the console lock
 878  * @fb_helper: driver-allocated fbdev helper, can be NULL
 879  * @suspend: whether to suspend or resume
 880  *
 881  * A wrapper around fb_set_suspend() that takes the console lock. If the lock
 882  * isn't available on resume, a worker is tasked with waiting for the lock
 883  * to become available. The console lock can be pretty contented on resume
 884  * due to all the printk activity.
 885  *
 886  * This function can be called multiple times with the same state since
 887  * &fb_info.state is checked to see if fbdev is running or not before locking.
 888  *
 889  * Use drm_fb_helper_set_suspend() if you need to take the lock yourself.
 890  */
 891 void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
 892                                         bool suspend)
 893 {
 894         if (!fb_helper || !fb_helper->fbdev)
 895                 return;
 896 
 897         /* make sure there's no pending/ongoing resume */
 898         flush_work(&fb_helper->resume_work);
 899 
 900         if (suspend) {
 901                 if (fb_helper->fbdev->state != FBINFO_STATE_RUNNING)
 902                         return;
 903 
 904                 console_lock();
 905 
 906         } else {
 907                 if (fb_helper->fbdev->state == FBINFO_STATE_RUNNING)
 908                         return;
 909 
 910                 if (!console_trylock()) {
 911                         schedule_work(&fb_helper->resume_work);
 912                         return;
 913                 }
 914         }
 915 
 916         fb_set_suspend(fb_helper->fbdev, suspend);
 917         console_unlock();
 918 }
 919 EXPORT_SYMBOL(drm_fb_helper_set_suspend_unlocked);
 920 
 921 static int setcmap_pseudo_palette(struct fb_cmap *cmap, struct fb_info *info)
 922 {
 923         u32 *palette = (u32 *)info->pseudo_palette;
 924         int i;
 925 
 926         if (cmap->start + cmap->len > 16)
 927                 return -EINVAL;
 928 
 929         for (i = 0; i < cmap->len; ++i) {
 930                 u16 red = cmap->red[i];
 931                 u16 green = cmap->green[i];
 932                 u16 blue = cmap->blue[i];
 933                 u32 value;
 934 
 935                 red >>= 16 - info->var.red.length;
 936                 green >>= 16 - info->var.green.length;
 937                 blue >>= 16 - info->var.blue.length;
 938                 value = (red << info->var.red.offset) |
 939                         (green << info->var.green.offset) |
 940                         (blue << info->var.blue.offset);
 941                 if (info->var.transp.length > 0) {
 942                         u32 mask = (1 << info->var.transp.length) - 1;
 943 
 944                         mask <<= info->var.transp.offset;
 945                         value |= mask;
 946                 }
 947                 palette[cmap->start + i] = value;
 948         }
 949 
 950         return 0;
 951 }
 952 
 953 static int setcmap_legacy(struct fb_cmap *cmap, struct fb_info *info)
 954 {
 955         struct drm_fb_helper *fb_helper = info->par;
 956         struct drm_mode_set *modeset;
 957         struct drm_crtc *crtc;
 958         u16 *r, *g, *b;
 959         int ret = 0;
 960 
 961         drm_modeset_lock_all(fb_helper->dev);
 962         drm_client_for_each_modeset(modeset, &fb_helper->client) {
 963                 crtc = modeset->crtc;
 964                 if (!crtc->funcs->gamma_set || !crtc->gamma_size)
 965                         return -EINVAL;
 966 
 967                 if (cmap->start + cmap->len > crtc->gamma_size)
 968                         return -EINVAL;
 969 
 970                 r = crtc->gamma_store;
 971                 g = r + crtc->gamma_size;
 972                 b = g + crtc->gamma_size;
 973 
 974                 memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
 975                 memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
 976                 memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
 977 
 978                 ret = crtc->funcs->gamma_set(crtc, r, g, b,
 979                                              crtc->gamma_size, NULL);
 980                 if (ret)
 981                         return ret;
 982         }
 983         drm_modeset_unlock_all(fb_helper->dev);
 984 
 985         return ret;
 986 }
 987 
 988 static struct drm_property_blob *setcmap_new_gamma_lut(struct drm_crtc *crtc,
 989                                                        struct fb_cmap *cmap)
 990 {
 991         struct drm_device *dev = crtc->dev;
 992         struct drm_property_blob *gamma_lut;
 993         struct drm_color_lut *lut;
 994         int size = crtc->gamma_size;
 995         int i;
 996 
 997         if (!size || cmap->start + cmap->len > size)
 998                 return ERR_PTR(-EINVAL);
 999 
1000         gamma_lut = drm_property_create_blob(dev, sizeof(*lut) * size, NULL);
1001         if (IS_ERR(gamma_lut))
1002                 return gamma_lut;
1003 
1004         lut = gamma_lut->data;
1005         if (cmap->start || cmap->len != size) {
1006                 u16 *r = crtc->gamma_store;
1007                 u16 *g = r + crtc->gamma_size;
1008                 u16 *b = g + crtc->gamma_size;
1009 
1010                 for (i = 0; i < cmap->start; i++) {
1011                         lut[i].red = r[i];
1012                         lut[i].green = g[i];
1013                         lut[i].blue = b[i];
1014                 }
1015                 for (i = cmap->start + cmap->len; i < size; i++) {
1016                         lut[i].red = r[i];
1017                         lut[i].green = g[i];
1018                         lut[i].blue = b[i];
1019                 }
1020         }
1021 
1022         for (i = 0; i < cmap->len; i++) {
1023                 lut[cmap->start + i].red = cmap->red[i];
1024                 lut[cmap->start + i].green = cmap->green[i];
1025                 lut[cmap->start + i].blue = cmap->blue[i];
1026         }
1027 
1028         return gamma_lut;
1029 }
1030 
1031 static int setcmap_atomic(struct fb_cmap *cmap, struct fb_info *info)
1032 {
1033         struct drm_fb_helper *fb_helper = info->par;
1034         struct drm_device *dev = fb_helper->dev;
1035         struct drm_property_blob *gamma_lut = NULL;
1036         struct drm_modeset_acquire_ctx ctx;
1037         struct drm_crtc_state *crtc_state;
1038         struct drm_atomic_state *state;
1039         struct drm_mode_set *modeset;
1040         struct drm_crtc *crtc;
1041         u16 *r, *g, *b;
1042         bool replaced;
1043         int ret = 0;
1044 
1045         drm_modeset_acquire_init(&ctx, 0);
1046 
1047         state = drm_atomic_state_alloc(dev);
1048         if (!state) {
1049                 ret = -ENOMEM;
1050                 goto out_ctx;
1051         }
1052 
1053         state->acquire_ctx = &ctx;
1054 retry:
1055         drm_client_for_each_modeset(modeset, &fb_helper->client) {
1056                 crtc = modeset->crtc;
1057 
1058                 if (!gamma_lut)
1059                         gamma_lut = setcmap_new_gamma_lut(crtc, cmap);
1060                 if (IS_ERR(gamma_lut)) {
1061                         ret = PTR_ERR(gamma_lut);
1062                         gamma_lut = NULL;
1063                         goto out_state;
1064                 }
1065 
1066                 crtc_state = drm_atomic_get_crtc_state(state, crtc);
1067                 if (IS_ERR(crtc_state)) {
1068                         ret = PTR_ERR(crtc_state);
1069                         goto out_state;
1070                 }
1071 
1072                 replaced  = drm_property_replace_blob(&crtc_state->degamma_lut,
1073                                                       NULL);
1074                 replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
1075                 replaced |= drm_property_replace_blob(&crtc_state->gamma_lut,
1076                                                       gamma_lut);
1077                 crtc_state->color_mgmt_changed |= replaced;
1078         }
1079 
1080         ret = drm_atomic_commit(state);
1081         if (ret)
1082                 goto out_state;
1083 
1084         drm_client_for_each_modeset(modeset, &fb_helper->client) {
1085                 crtc = modeset->crtc;
1086 
1087                 r = crtc->gamma_store;
1088                 g = r + crtc->gamma_size;
1089                 b = g + crtc->gamma_size;
1090 
1091                 memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
1092                 memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
1093                 memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
1094         }
1095 
1096 out_state:
1097         if (ret == -EDEADLK)
1098                 goto backoff;
1099 
1100         drm_property_blob_put(gamma_lut);
1101         drm_atomic_state_put(state);
1102 out_ctx:
1103         drm_modeset_drop_locks(&ctx);
1104         drm_modeset_acquire_fini(&ctx);
1105 
1106         return ret;
1107 
1108 backoff:
1109         drm_atomic_state_clear(state);
1110         drm_modeset_backoff(&ctx);
1111         goto retry;
1112 }
1113 
1114 /**
1115  * drm_fb_helper_setcmap - implementation for &fb_ops.fb_setcmap
1116  * @cmap: cmap to set
1117  * @info: fbdev registered by the helper
1118  */
1119 int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
1120 {
1121         struct drm_fb_helper *fb_helper = info->par;
1122         struct drm_device *dev = fb_helper->dev;
1123         int ret;
1124 
1125         if (oops_in_progress)
1126                 return -EBUSY;
1127 
1128         mutex_lock(&fb_helper->lock);
1129 
1130         if (!drm_master_internal_acquire(dev)) {
1131                 ret = -EBUSY;
1132                 goto unlock;
1133         }
1134 
1135         mutex_lock(&fb_helper->client.modeset_mutex);
1136         if (info->fix.visual == FB_VISUAL_TRUECOLOR)
1137                 ret = setcmap_pseudo_palette(cmap, info);
1138         else if (drm_drv_uses_atomic_modeset(fb_helper->dev))
1139                 ret = setcmap_atomic(cmap, info);
1140         else
1141                 ret = setcmap_legacy(cmap, info);
1142         mutex_unlock(&fb_helper->client.modeset_mutex);
1143 
1144         drm_master_internal_release(dev);
1145 unlock:
1146         mutex_unlock(&fb_helper->lock);
1147 
1148         return ret;
1149 }
1150 EXPORT_SYMBOL(drm_fb_helper_setcmap);
1151 
1152 /**
1153  * drm_fb_helper_ioctl - legacy ioctl implementation
1154  * @info: fbdev registered by the helper
1155  * @cmd: ioctl command
1156  * @arg: ioctl argument
1157  *
1158  * A helper to implement the standard fbdev ioctl. Only
1159  * FBIO_WAITFORVSYNC is implemented for now.
1160  */
1161 int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
1162                         unsigned long arg)
1163 {
1164         struct drm_fb_helper *fb_helper = info->par;
1165         struct drm_device *dev = fb_helper->dev;
1166         struct drm_crtc *crtc;
1167         int ret = 0;
1168 
1169         mutex_lock(&fb_helper->lock);
1170         if (!drm_master_internal_acquire(dev)) {
1171                 ret = -EBUSY;
1172                 goto unlock;
1173         }
1174 
1175         switch (cmd) {
1176         case FBIO_WAITFORVSYNC:
1177                 /*
1178                  * Only consider the first CRTC.
1179                  *
1180                  * This ioctl is supposed to take the CRTC number as
1181                  * an argument, but in fbdev times, what that number
1182                  * was supposed to be was quite unclear, different
1183                  * drivers were passing that argument differently
1184                  * (some by reference, some by value), and most of the
1185                  * userspace applications were just hardcoding 0 as an
1186                  * argument.
1187                  *
1188                  * The first CRTC should be the integrated panel on
1189                  * most drivers, so this is the best choice we can
1190                  * make. If we're not smart enough here, one should
1191                  * just consider switch the userspace to KMS.
1192                  */
1193                 crtc = fb_helper->client.modesets[0].crtc;
1194 
1195                 /*
1196                  * Only wait for a vblank event if the CRTC is
1197                  * enabled, otherwise just don't do anythintg,
1198                  * not even report an error.
1199                  */
1200                 ret = drm_crtc_vblank_get(crtc);
1201                 if (!ret) {
1202                         drm_crtc_wait_one_vblank(crtc);
1203                         drm_crtc_vblank_put(crtc);
1204                 }
1205 
1206                 ret = 0;
1207                 break;
1208         default:
1209                 ret = -ENOTTY;
1210         }
1211 
1212         drm_master_internal_release(dev);
1213 unlock:
1214         mutex_unlock(&fb_helper->lock);
1215         return ret;
1216 }
1217 EXPORT_SYMBOL(drm_fb_helper_ioctl);
1218 
1219 static bool drm_fb_pixel_format_equal(const struct fb_var_screeninfo *var_1,
1220                                       const struct fb_var_screeninfo *var_2)
1221 {
1222         return var_1->bits_per_pixel == var_2->bits_per_pixel &&
1223                var_1->grayscale == var_2->grayscale &&
1224                var_1->red.offset == var_2->red.offset &&
1225                var_1->red.length == var_2->red.length &&
1226                var_1->red.msb_right == var_2->red.msb_right &&
1227                var_1->green.offset == var_2->green.offset &&
1228                var_1->green.length == var_2->green.length &&
1229                var_1->green.msb_right == var_2->green.msb_right &&
1230                var_1->blue.offset == var_2->blue.offset &&
1231                var_1->blue.length == var_2->blue.length &&
1232                var_1->blue.msb_right == var_2->blue.msb_right &&
1233                var_1->transp.offset == var_2->transp.offset &&
1234                var_1->transp.length == var_2->transp.length &&
1235                var_1->transp.msb_right == var_2->transp.msb_right;
1236 }
1237 
1238 static void drm_fb_helper_fill_pixel_fmt(struct fb_var_screeninfo *var,
1239                                          u8 depth)
1240 {
1241         switch (depth) {
1242         case 8:
1243                 var->red.offset = 0;
1244                 var->green.offset = 0;
1245                 var->blue.offset = 0;
1246                 var->red.length = 8; /* 8bit DAC */
1247                 var->green.length = 8;
1248                 var->blue.length = 8;
1249                 var->transp.offset = 0;
1250                 var->transp.length = 0;
1251                 break;
1252         case 15:
1253                 var->red.offset = 10;
1254                 var->green.offset = 5;
1255                 var->blue.offset = 0;
1256                 var->red.length = 5;
1257                 var->green.length = 5;
1258                 var->blue.length = 5;
1259                 var->transp.offset = 15;
1260                 var->transp.length = 1;
1261                 break;
1262         case 16:
1263                 var->red.offset = 11;
1264                 var->green.offset = 5;
1265                 var->blue.offset = 0;
1266                 var->red.length = 5;
1267                 var->green.length = 6;
1268                 var->blue.length = 5;
1269                 var->transp.offset = 0;
1270                 break;
1271         case 24:
1272                 var->red.offset = 16;
1273                 var->green.offset = 8;
1274                 var->blue.offset = 0;
1275                 var->red.length = 8;
1276                 var->green.length = 8;
1277                 var->blue.length = 8;
1278                 var->transp.offset = 0;
1279                 var->transp.length = 0;
1280                 break;
1281         case 32:
1282                 var->red.offset = 16;
1283                 var->green.offset = 8;
1284                 var->blue.offset = 0;
1285                 var->red.length = 8;
1286                 var->green.length = 8;
1287                 var->blue.length = 8;
1288                 var->transp.offset = 24;
1289                 var->transp.length = 8;
1290                 break;
1291         default:
1292                 break;
1293         }
1294 }
1295 
1296 /**
1297  * drm_fb_helper_check_var - implementation for &fb_ops.fb_check_var
1298  * @var: screeninfo to check
1299  * @info: fbdev registered by the helper
1300  */
1301 int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
1302                             struct fb_info *info)
1303 {
1304         struct drm_fb_helper *fb_helper = info->par;
1305         struct drm_framebuffer *fb = fb_helper->fb;
1306 
1307         if (in_dbg_master())
1308                 return -EINVAL;
1309 
1310         if (var->pixclock != 0) {
1311                 DRM_DEBUG("fbdev emulation doesn't support changing the pixel clock, value of pixclock is ignored\n");
1312                 var->pixclock = 0;
1313         }
1314 
1315         if ((drm_format_info_block_width(fb->format, 0) > 1) ||
1316             (drm_format_info_block_height(fb->format, 0) > 1))
1317                 return -EINVAL;
1318 
1319         /*
1320          * Changes struct fb_var_screeninfo are currently not pushed back
1321          * to KMS, hence fail if different settings are requested.
1322          */
1323         if (var->bits_per_pixel > fb->format->cpp[0] * 8 ||
1324             var->xres > fb->width || var->yres > fb->height ||
1325             var->xres_virtual > fb->width || var->yres_virtual > fb->height) {
1326                 DRM_DEBUG("fb requested width/height/bpp can't fit in current fb "
1327                           "request %dx%d-%d (virtual %dx%d) > %dx%d-%d\n",
1328                           var->xres, var->yres, var->bits_per_pixel,
1329                           var->xres_virtual, var->yres_virtual,
1330                           fb->width, fb->height, fb->format->cpp[0] * 8);
1331                 return -EINVAL;
1332         }
1333 
1334         /*
1335          * Workaround for SDL 1.2, which is known to be setting all pixel format
1336          * fields values to zero in some cases. We treat this situation as a
1337          * kind of "use some reasonable autodetected values".
1338          */
1339         if (!var->red.offset     && !var->green.offset    &&
1340             !var->blue.offset    && !var->transp.offset   &&
1341             !var->red.length     && !var->green.length    &&
1342             !var->blue.length    && !var->transp.length   &&
1343             !var->red.msb_right  && !var->green.msb_right &&
1344             !var->blue.msb_right && !var->transp.msb_right) {
1345                 drm_fb_helper_fill_pixel_fmt(var, fb->format->depth);
1346         }
1347 
1348         /*
1349          * Likewise, bits_per_pixel should be rounded up to a supported value.
1350          */
1351         var->bits_per_pixel = fb->format->cpp[0] * 8;
1352 
1353         /*
1354          * drm fbdev emulation doesn't support changing the pixel format at all,
1355          * so reject all pixel format changing requests.
1356          */
1357         if (!drm_fb_pixel_format_equal(var, &info->var)) {
1358                 DRM_DEBUG("fbdev emulation doesn't support changing the pixel format\n");
1359                 return -EINVAL;
1360         }
1361 
1362         return 0;
1363 }
1364 EXPORT_SYMBOL(drm_fb_helper_check_var);
1365 
1366 /**
1367  * drm_fb_helper_set_par - implementation for &fb_ops.fb_set_par
1368  * @info: fbdev registered by the helper
1369  *
1370  * This will let fbcon do the mode init and is called at initialization time by
1371  * the fbdev core when registering the driver, and later on through the hotplug
1372  * callback.
1373  */
1374 int drm_fb_helper_set_par(struct fb_info *info)
1375 {
1376         struct drm_fb_helper *fb_helper = info->par;
1377         struct fb_var_screeninfo *var = &info->var;
1378 
1379         if (oops_in_progress)
1380                 return -EBUSY;
1381 
1382         if (var->pixclock != 0) {
1383                 DRM_ERROR("PIXEL CLOCK SET\n");
1384                 return -EINVAL;
1385         }
1386 
1387         drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper);
1388 
1389         return 0;
1390 }
1391 EXPORT_SYMBOL(drm_fb_helper_set_par);
1392 
1393 static void pan_set(struct drm_fb_helper *fb_helper, int x, int y)
1394 {
1395         struct drm_mode_set *mode_set;
1396 
1397         mutex_lock(&fb_helper->client.modeset_mutex);
1398         drm_client_for_each_modeset(mode_set, &fb_helper->client) {
1399                 mode_set->x = x;
1400                 mode_set->y = y;
1401         }
1402         mutex_unlock(&fb_helper->client.modeset_mutex);
1403 }
1404 
1405 static int pan_display_atomic(struct fb_var_screeninfo *var,
1406                               struct fb_info *info)
1407 {
1408         struct drm_fb_helper *fb_helper = info->par;
1409         int ret;
1410 
1411         pan_set(fb_helper, var->xoffset, var->yoffset);
1412 
1413         ret = drm_client_modeset_commit_force(&fb_helper->client);
1414         if (!ret) {
1415                 info->var.xoffset = var->xoffset;
1416                 info->var.yoffset = var->yoffset;
1417         } else
1418                 pan_set(fb_helper, info->var.xoffset, info->var.yoffset);
1419 
1420         return ret;
1421 }
1422 
1423 static int pan_display_legacy(struct fb_var_screeninfo *var,
1424                               struct fb_info *info)
1425 {
1426         struct drm_fb_helper *fb_helper = info->par;
1427         struct drm_client_dev *client = &fb_helper->client;
1428         struct drm_mode_set *modeset;
1429         int ret = 0;
1430 
1431         mutex_lock(&client->modeset_mutex);
1432         drm_modeset_lock_all(fb_helper->dev);
1433         drm_client_for_each_modeset(modeset, client) {
1434                 modeset->x = var->xoffset;
1435                 modeset->y = var->yoffset;
1436 
1437                 if (modeset->num_connectors) {
1438                         ret = drm_mode_set_config_internal(modeset);
1439                         if (!ret) {
1440                                 info->var.xoffset = var->xoffset;
1441                                 info->var.yoffset = var->yoffset;
1442                         }
1443                 }
1444         }
1445         drm_modeset_unlock_all(fb_helper->dev);
1446         mutex_unlock(&client->modeset_mutex);
1447 
1448         return ret;
1449 }
1450 
1451 /**
1452  * drm_fb_helper_pan_display - implementation for &fb_ops.fb_pan_display
1453  * @var: updated screen information
1454  * @info: fbdev registered by the helper
1455  */
1456 int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
1457                               struct fb_info *info)
1458 {
1459         struct drm_fb_helper *fb_helper = info->par;
1460         struct drm_device *dev = fb_helper->dev;
1461         int ret;
1462 
1463         if (oops_in_progress)
1464                 return -EBUSY;
1465 
1466         mutex_lock(&fb_helper->lock);
1467         if (!drm_master_internal_acquire(dev)) {
1468                 ret = -EBUSY;
1469                 goto unlock;
1470         }
1471 
1472         if (drm_drv_uses_atomic_modeset(dev))
1473                 ret = pan_display_atomic(var, info);
1474         else
1475                 ret = pan_display_legacy(var, info);
1476 
1477         drm_master_internal_release(dev);
1478 unlock:
1479         mutex_unlock(&fb_helper->lock);
1480 
1481         return ret;
1482 }
1483 EXPORT_SYMBOL(drm_fb_helper_pan_display);
1484 
1485 /*
1486  * Allocates the backing storage and sets up the fbdev info structure through
1487  * the ->fb_probe callback.
1488  */
1489 static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
1490                                          int preferred_bpp)
1491 {
1492         struct drm_client_dev *client = &fb_helper->client;
1493         int ret = 0;
1494         int crtc_count = 0;
1495         struct drm_connector_list_iter conn_iter;
1496         struct drm_fb_helper_surface_size sizes;
1497         struct drm_connector *connector;
1498         struct drm_mode_set *mode_set;
1499         int best_depth = 0;
1500 
1501         memset(&sizes, 0, sizeof(struct drm_fb_helper_surface_size));
1502         sizes.surface_depth = 24;
1503         sizes.surface_bpp = 32;
1504         sizes.fb_width = (u32)-1;
1505         sizes.fb_height = (u32)-1;
1506 
1507         /*
1508          * If driver picks 8 or 16 by default use that for both depth/bpp
1509          * to begin with
1510          */
1511         if (preferred_bpp != sizes.surface_bpp)
1512                 sizes.surface_depth = sizes.surface_bpp = preferred_bpp;
1513 
1514         drm_connector_list_iter_begin(fb_helper->dev, &conn_iter);
1515         drm_client_for_each_connector_iter(connector, &conn_iter) {
1516                 struct drm_cmdline_mode *cmdline_mode;
1517 
1518                 cmdline_mode = &connector->cmdline_mode;
1519 
1520                 if (cmdline_mode->bpp_specified) {
1521                         switch (cmdline_mode->bpp) {
1522                         case 8:
1523                                 sizes.surface_depth = sizes.surface_bpp = 8;
1524                                 break;
1525                         case 15:
1526                                 sizes.surface_depth = 15;
1527                                 sizes.surface_bpp = 16;
1528                                 break;
1529                         case 16:
1530                                 sizes.surface_depth = sizes.surface_bpp = 16;
1531                                 break;
1532                         case 24:
1533                                 sizes.surface_depth = sizes.surface_bpp = 24;
1534                                 break;
1535                         case 32:
1536                                 sizes.surface_depth = 24;
1537                                 sizes.surface_bpp = 32;
1538                                 break;
1539                         }
1540                         break;
1541                 }
1542         }
1543         drm_connector_list_iter_end(&conn_iter);
1544 
1545         /*
1546          * If we run into a situation where, for example, the primary plane
1547          * supports RGBA5551 (16 bpp, depth 15) but not RGB565 (16 bpp, depth
1548          * 16) we need to scale down the depth of the sizes we request.
1549          */
1550         mutex_lock(&client->modeset_mutex);
1551         drm_client_for_each_modeset(mode_set, client) {
1552                 struct drm_crtc *crtc = mode_set->crtc;
1553                 struct drm_plane *plane = crtc->primary;
1554                 int j;
1555 
1556                 DRM_DEBUG("test CRTC %u primary plane\n", drm_crtc_index(crtc));
1557 
1558                 for (j = 0; j < plane->format_count; j++) {
1559                         const struct drm_format_info *fmt;
1560 
1561                         fmt = drm_format_info(plane->format_types[j]);
1562 
1563                         /*
1564                          * Do not consider YUV or other complicated formats
1565                          * for framebuffers. This means only legacy formats
1566                          * are supported (fmt->depth is a legacy field) but
1567                          * the framebuffer emulation can only deal with such
1568                          * formats, specifically RGB/BGA formats.
1569                          */
1570                         if (fmt->depth == 0)
1571                                 continue;
1572 
1573                         /* We found a perfect fit, great */
1574                         if (fmt->depth == sizes.surface_depth) {
1575                                 best_depth = fmt->depth;
1576                                 break;
1577                         }
1578 
1579                         /* Skip depths above what we're looking for */
1580                         if (fmt->depth > sizes.surface_depth)
1581                                 continue;
1582 
1583                         /* Best depth found so far */
1584                         if (fmt->depth > best_depth)
1585                                 best_depth = fmt->depth;
1586                 }
1587         }
1588         if (sizes.surface_depth != best_depth && best_depth) {
1589                 DRM_INFO("requested bpp %d, scaled depth down to %d",
1590                          sizes.surface_bpp, best_depth);
1591                 sizes.surface_depth = best_depth;
1592         }
1593 
1594         /* first up get a count of crtcs now in use and new min/maxes width/heights */
1595         crtc_count = 0;
1596         drm_client_for_each_modeset(mode_set, client) {
1597                 struct drm_display_mode *desired_mode;
1598                 int x, y, j;
1599                 /* in case of tile group, are we the last tile vert or horiz?
1600                  * If no tile group you are always the last one both vertically
1601                  * and horizontally
1602                  */
1603                 bool lastv = true, lasth = true;
1604 
1605                 desired_mode = mode_set->mode;
1606 
1607                 if (!desired_mode)
1608                         continue;
1609 
1610                 crtc_count++;
1611 
1612                 x = mode_set->x;
1613                 y = mode_set->y;
1614 
1615                 sizes.surface_width  = max_t(u32, desired_mode->hdisplay + x, sizes.surface_width);
1616                 sizes.surface_height = max_t(u32, desired_mode->vdisplay + y, sizes.surface_height);
1617 
1618                 for (j = 0; j < mode_set->num_connectors; j++) {
1619                         struct drm_connector *connector = mode_set->connectors[j];
1620 
1621                         if (connector->has_tile) {
1622                                 lasth = (connector->tile_h_loc == (connector->num_h_tile - 1));
1623                                 lastv = (connector->tile_v_loc == (connector->num_v_tile - 1));
1624                                 /* cloning to multiple tiles is just crazy-talk, so: */
1625                                 break;
1626                         }
1627                 }
1628 
1629                 if (lasth)
1630                         sizes.fb_width  = min_t(u32, desired_mode->hdisplay + x, sizes.fb_width);
1631                 if (lastv)
1632                         sizes.fb_height = min_t(u32, desired_mode->vdisplay + y, sizes.fb_height);
1633         }
1634         mutex_unlock(&client->modeset_mutex);
1635 
1636         if (crtc_count == 0 || sizes.fb_width == -1 || sizes.fb_height == -1) {
1637                 DRM_INFO("Cannot find any crtc or sizes\n");
1638 
1639                 /* First time: disable all crtc's.. */
1640                 if (!fb_helper->deferred_setup)
1641                         drm_client_modeset_commit(client);
1642                 return -EAGAIN;
1643         }
1644 
1645         /* Handle our overallocation */
1646         sizes.surface_height *= drm_fbdev_overalloc;
1647         sizes.surface_height /= 100;
1648 
1649         /* push down into drivers */
1650         ret = (*fb_helper->funcs->fb_probe)(fb_helper, &sizes);
1651         if (ret < 0)
1652                 return ret;
1653 
1654         strcpy(fb_helper->fb->comm, "[fbcon]");
1655         return 0;
1656 }
1657 
1658 static void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
1659                                    uint32_t depth)
1660 {
1661         info->fix.type = FB_TYPE_PACKED_PIXELS;
1662         info->fix.visual = depth == 8 ? FB_VISUAL_PSEUDOCOLOR :
1663                 FB_VISUAL_TRUECOLOR;
1664         info->fix.mmio_start = 0;
1665         info->fix.mmio_len = 0;
1666         info->fix.type_aux = 0;
1667         info->fix.xpanstep = 1; /* doing it in hw */
1668         info->fix.ypanstep = 1; /* doing it in hw */
1669         info->fix.ywrapstep = 0;
1670         info->fix.accel = FB_ACCEL_NONE;
1671 
1672         info->fix.line_length = pitch;
1673 }
1674 
1675 static void drm_fb_helper_fill_var(struct fb_info *info,
1676                                    struct drm_fb_helper *fb_helper,
1677                                    uint32_t fb_width, uint32_t fb_height)
1678 {
1679         struct drm_framebuffer *fb = fb_helper->fb;
1680 
1681         WARN_ON((drm_format_info_block_width(fb->format, 0) > 1) ||
1682                 (drm_format_info_block_height(fb->format, 0) > 1));
1683         info->pseudo_palette = fb_helper->pseudo_palette;
1684         info->var.xres_virtual = fb->width;
1685         info->var.yres_virtual = fb->height;
1686         info->var.bits_per_pixel = fb->format->cpp[0] * 8;
1687         info->var.accel_flags = FB_ACCELF_TEXT;
1688         info->var.xoffset = 0;
1689         info->var.yoffset = 0;
1690         info->var.activate = FB_ACTIVATE_NOW;
1691 
1692         drm_fb_helper_fill_pixel_fmt(&info->var, fb->format->depth);
1693 
1694         info->var.xres = fb_width;
1695         info->var.yres = fb_height;
1696 }
1697 
1698 /**
1699  * drm_fb_helper_fill_info - initializes fbdev information
1700  * @info: fbdev instance to set up
1701  * @fb_helper: fb helper instance to use as template
1702  * @sizes: describes fbdev size and scanout surface size
1703  *
1704  * Sets up the variable and fixed fbdev metainformation from the given fb helper
1705  * instance and the drm framebuffer allocated in &drm_fb_helper.fb.
1706  *
1707  * Drivers should call this (or their equivalent setup code) from their
1708  * &drm_fb_helper_funcs.fb_probe callback after having allocated the fbdev
1709  * backing storage framebuffer.
1710  */
1711 void drm_fb_helper_fill_info(struct fb_info *info,
1712                              struct drm_fb_helper *fb_helper,
1713                              struct drm_fb_helper_surface_size *sizes)
1714 {
1715         struct drm_framebuffer *fb = fb_helper->fb;
1716 
1717         drm_fb_helper_fill_fix(info, fb->pitches[0], fb->format->depth);
1718         drm_fb_helper_fill_var(info, fb_helper,
1719                                sizes->fb_width, sizes->fb_height);
1720 
1721         info->par = fb_helper;
1722         snprintf(info->fix.id, sizeof(info->fix.id), "%sdrmfb",
1723                  fb_helper->dev->driver->name);
1724 
1725 }
1726 EXPORT_SYMBOL(drm_fb_helper_fill_info);
1727 
1728 /*
1729  * This is a continuation of drm_setup_crtcs() that sets up anything related
1730  * to the framebuffer. During initialization, drm_setup_crtcs() is called before
1731  * the framebuffer has been allocated (fb_helper->fb and fb_helper->fbdev).
1732  * So, any setup that touches those fields needs to be done here instead of in
1733  * drm_setup_crtcs().
1734  */
1735 static void drm_setup_crtcs_fb(struct drm_fb_helper *fb_helper)
1736 {
1737         struct drm_client_dev *client = &fb_helper->client;
1738         struct drm_connector_list_iter conn_iter;
1739         struct fb_info *info = fb_helper->fbdev;
1740         unsigned int rotation, sw_rotations = 0;
1741         struct drm_connector *connector;
1742         struct drm_mode_set *modeset;
1743 
1744         mutex_lock(&client->modeset_mutex);
1745         drm_client_for_each_modeset(modeset, client) {
1746                 if (!modeset->num_connectors)
1747                         continue;
1748 
1749                 modeset->fb = fb_helper->fb;
1750 
1751                 if (drm_client_rotation(modeset, &rotation))
1752                         /* Rotating in hardware, fbcon should not rotate */
1753                         sw_rotations |= DRM_MODE_ROTATE_0;
1754                 else
1755                         sw_rotations |= rotation;
1756         }
1757         mutex_unlock(&client->modeset_mutex);
1758 
1759         drm_connector_list_iter_begin(fb_helper->dev, &conn_iter);
1760         drm_client_for_each_connector_iter(connector, &conn_iter) {
1761 
1762                 /* use first connected connector for the physical dimensions */
1763                 if (connector->status == connector_status_connected) {
1764                         info->var.width = connector->display_info.width_mm;
1765                         info->var.height = connector->display_info.height_mm;
1766                         break;
1767                 }
1768         }
1769         drm_connector_list_iter_end(&conn_iter);
1770 
1771         switch (sw_rotations) {
1772         case DRM_MODE_ROTATE_0:
1773                 info->fbcon_rotate_hint = FB_ROTATE_UR;
1774                 break;
1775         case DRM_MODE_ROTATE_90:
1776                 info->fbcon_rotate_hint = FB_ROTATE_CCW;
1777                 break;
1778         case DRM_MODE_ROTATE_180:
1779                 info->fbcon_rotate_hint = FB_ROTATE_UD;
1780                 break;
1781         case DRM_MODE_ROTATE_270:
1782                 info->fbcon_rotate_hint = FB_ROTATE_CW;
1783                 break;
1784         default:
1785                 /*
1786                  * Multiple bits are set / multiple rotations requested
1787                  * fbcon cannot handle separate rotation settings per
1788                  * output, so fallback to unrotated.
1789                  */
1790                 info->fbcon_rotate_hint = FB_ROTATE_UR;
1791         }
1792 }
1793 
1794 /* Note: Drops fb_helper->lock before returning. */
1795 static int
1796 __drm_fb_helper_initial_config_and_unlock(struct drm_fb_helper *fb_helper,
1797                                           int bpp_sel)
1798 {
1799         struct drm_device *dev = fb_helper->dev;
1800         struct fb_info *info;
1801         unsigned int width, height;
1802         int ret;
1803 
1804         width = dev->mode_config.max_width;
1805         height = dev->mode_config.max_height;
1806 
1807         drm_client_modeset_probe(&fb_helper->client, width, height);
1808         ret = drm_fb_helper_single_fb_probe(fb_helper, bpp_sel);
1809         if (ret < 0) {
1810                 if (ret == -EAGAIN) {
1811                         fb_helper->preferred_bpp = bpp_sel;
1812                         fb_helper->deferred_setup = true;
1813                         ret = 0;
1814                 }
1815                 mutex_unlock(&fb_helper->lock);
1816 
1817                 return ret;
1818         }
1819         drm_setup_crtcs_fb(fb_helper);
1820 
1821         fb_helper->deferred_setup = false;
1822 
1823         info = fb_helper->fbdev;
1824         info->var.pixclock = 0;
1825         /* Shamelessly allow physical address leaking to userspace */
1826 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
1827         if (!drm_leak_fbdev_smem)
1828 #endif
1829                 /* don't leak any physical addresses to userspace */
1830                 info->flags |= FBINFO_HIDE_SMEM_START;
1831 
1832         /* Need to drop locks to avoid recursive deadlock in
1833          * register_framebuffer. This is ok because the only thing left to do is
1834          * register the fbdev emulation instance in kernel_fb_helper_list. */
1835         mutex_unlock(&fb_helper->lock);
1836 
1837         ret = register_framebuffer(info);
1838         if (ret < 0)
1839                 return ret;
1840 
1841         dev_info(dev->dev, "fb%d: %s frame buffer device\n",
1842                  info->node, info->fix.id);
1843 
1844         mutex_lock(&kernel_fb_helper_lock);
1845         if (list_empty(&kernel_fb_helper_list))
1846                 register_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
1847 
1848         list_add(&fb_helper->kernel_fb_list, &kernel_fb_helper_list);
1849         mutex_unlock(&kernel_fb_helper_lock);
1850 
1851         return 0;
1852 }
1853 
1854 /**
1855  * drm_fb_helper_initial_config - setup a sane initial connector configuration
1856  * @fb_helper: fb_helper device struct
1857  * @bpp_sel: bpp value to use for the framebuffer configuration
1858  *
1859  * Scans the CRTCs and connectors and tries to put together an initial setup.
1860  * At the moment, this is a cloned configuration across all heads with
1861  * a new framebuffer object as the backing store.
1862  *
1863  * Note that this also registers the fbdev and so allows userspace to call into
1864  * the driver through the fbdev interfaces.
1865  *
1866  * This function will call down into the &drm_fb_helper_funcs.fb_probe callback
1867  * to let the driver allocate and initialize the fbdev info structure and the
1868  * drm framebuffer used to back the fbdev. drm_fb_helper_fill_info() is provided
1869  * as a helper to setup simple default values for the fbdev info structure.
1870  *
1871  * HANG DEBUGGING:
1872  *
1873  * When you have fbcon support built-in or already loaded, this function will do
1874  * a full modeset to setup the fbdev console. Due to locking misdesign in the
1875  * VT/fbdev subsystem that entire modeset sequence has to be done while holding
1876  * console_lock. Until console_unlock is called no dmesg lines will be sent out
1877  * to consoles, not even serial console. This means when your driver crashes,
1878  * you will see absolutely nothing else but a system stuck in this function,
1879  * with no further output. Any kind of printk() you place within your own driver
1880  * or in the drm core modeset code will also never show up.
1881  *
1882  * Standard debug practice is to run the fbcon setup without taking the
1883  * console_lock as a hack, to be able to see backtraces and crashes on the
1884  * serial line. This can be done by setting the fb.lockless_register_fb=1 kernel
1885  * cmdline option.
1886  *
1887  * The other option is to just disable fbdev emulation since very likely the
1888  * first modeset from userspace will crash in the same way, and is even easier
1889  * to debug. This can be done by setting the drm_kms_helper.fbdev_emulation=0
1890  * kernel cmdline option.
1891  *
1892  * RETURNS:
1893  * Zero if everything went ok, nonzero otherwise.
1894  */
1895 int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel)
1896 {
1897         int ret;
1898 
1899         if (!drm_fbdev_emulation)
1900                 return 0;
1901 
1902         mutex_lock(&fb_helper->lock);
1903         ret = __drm_fb_helper_initial_config_and_unlock(fb_helper, bpp_sel);
1904 
1905         return ret;
1906 }
1907 EXPORT_SYMBOL(drm_fb_helper_initial_config);
1908 
1909 /**
1910  * drm_fb_helper_hotplug_event - respond to a hotplug notification by
1911  *                               probing all the outputs attached to the fb
1912  * @fb_helper: driver-allocated fbdev helper, can be NULL
1913  *
1914  * Scan the connectors attached to the fb_helper and try to put together a
1915  * setup after notification of a change in output configuration.
1916  *
1917  * Called at runtime, takes the mode config locks to be able to check/change the
1918  * modeset configuration. Must be run from process context (which usually means
1919  * either the output polling work or a work item launched from the driver's
1920  * hotplug interrupt).
1921  *
1922  * Note that drivers may call this even before calling
1923  * drm_fb_helper_initial_config but only after drm_fb_helper_init. This allows
1924  * for a race-free fbcon setup and will make sure that the fbdev emulation will
1925  * not miss any hotplug events.
1926  *
1927  * RETURNS:
1928  * 0 on success and a non-zero error code otherwise.
1929  */
1930 int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
1931 {
1932         int err = 0;
1933 
1934         if (!drm_fbdev_emulation || !fb_helper)
1935                 return 0;
1936 
1937         mutex_lock(&fb_helper->lock);
1938         if (fb_helper->deferred_setup) {
1939                 err = __drm_fb_helper_initial_config_and_unlock(fb_helper,
1940                                 fb_helper->preferred_bpp);
1941                 return err;
1942         }
1943 
1944         if (!fb_helper->fb || !drm_master_internal_acquire(fb_helper->dev)) {
1945                 fb_helper->delayed_hotplug = true;
1946                 mutex_unlock(&fb_helper->lock);
1947                 return err;
1948         }
1949 
1950         drm_master_internal_release(fb_helper->dev);
1951 
1952         DRM_DEBUG_KMS("\n");
1953 
1954         drm_client_modeset_probe(&fb_helper->client, fb_helper->fb->width, fb_helper->fb->height);
1955         drm_setup_crtcs_fb(fb_helper);
1956         mutex_unlock(&fb_helper->lock);
1957 
1958         drm_fb_helper_set_par(fb_helper->fbdev);
1959 
1960         return 0;
1961 }
1962 EXPORT_SYMBOL(drm_fb_helper_hotplug_event);
1963 
1964 /**
1965  * drm_fb_helper_fbdev_setup() - Setup fbdev emulation
1966  * @dev: DRM device
1967  * @fb_helper: fbdev helper structure to set up
1968  * @funcs: fbdev helper functions
1969  * @preferred_bpp: Preferred bits per pixel for the device.
1970  *                 @dev->mode_config.preferred_depth is used if this is zero.
1971  * @max_conn_count: Maximum number of connectors (not used)
1972  *
1973  * This function sets up fbdev emulation and registers fbdev for access by
1974  * userspace. If all connectors are disconnected, setup is deferred to the next
1975  * time drm_fb_helper_hotplug_event() is called.
1976  * The caller must to provide a &drm_fb_helper_funcs->fb_probe callback
1977  * function.
1978  *
1979  * Use drm_fb_helper_fbdev_teardown() to destroy the fbdev.
1980  *
1981  * See also: drm_fb_helper_initial_config(), drm_fbdev_generic_setup().
1982  *
1983  * Returns:
1984  * Zero on success or negative error code on failure.
1985  */
1986 int drm_fb_helper_fbdev_setup(struct drm_device *dev,
1987                               struct drm_fb_helper *fb_helper,
1988                               const struct drm_fb_helper_funcs *funcs,
1989                               unsigned int preferred_bpp,
1990                               unsigned int max_conn_count)
1991 {
1992         int ret;
1993 
1994         if (!preferred_bpp)
1995                 preferred_bpp = dev->mode_config.preferred_depth;
1996         if (!preferred_bpp)
1997                 preferred_bpp = 32;
1998 
1999         drm_fb_helper_prepare(dev, fb_helper, funcs);
2000 
2001         ret = drm_fb_helper_init(dev, fb_helper, 0);
2002         if (ret < 0) {
2003                 DRM_DEV_ERROR(dev->dev, "fbdev: Failed to initialize (ret=%d)\n", ret);
2004                 return ret;
2005         }
2006 
2007         if (!drm_drv_uses_atomic_modeset(dev))
2008                 drm_helper_disable_unused_functions(dev);
2009 
2010         ret = drm_fb_helper_initial_config(fb_helper, preferred_bpp);
2011         if (ret < 0) {
2012                 DRM_DEV_ERROR(dev->dev, "fbdev: Failed to set configuration (ret=%d)\n", ret);
2013                 goto err_drm_fb_helper_fini;
2014         }
2015 
2016         return 0;
2017 
2018 err_drm_fb_helper_fini:
2019         drm_fb_helper_fbdev_teardown(dev);
2020 
2021         return ret;
2022 }
2023 EXPORT_SYMBOL(drm_fb_helper_fbdev_setup);
2024 
2025 /**
2026  * drm_fb_helper_fbdev_teardown - Tear down fbdev emulation
2027  * @dev: DRM device
2028  *
2029  * This function unregisters fbdev if not already done and cleans up the
2030  * associated resources including the &drm_framebuffer.
2031  * The driver is responsible for freeing the &drm_fb_helper structure which is
2032  * stored in &drm_device->fb_helper. Do note that this pointer has been cleared
2033  * when this function returns.
2034  *
2035  * In order to support device removal/unplug while file handles are still open,
2036  * drm_fb_helper_unregister_fbi() should be called on device removal and
2037  * drm_fb_helper_fbdev_teardown() in the &drm_driver->release callback when
2038  * file handles are closed.
2039  */
2040 void drm_fb_helper_fbdev_teardown(struct drm_device *dev)
2041 {
2042         struct drm_fb_helper *fb_helper = dev->fb_helper;
2043         struct fb_ops *fbops = NULL;
2044 
2045         if (!fb_helper)
2046                 return;
2047 
2048         /* Unregister if it hasn't been done already */
2049         if (fb_helper->fbdev && fb_helper->fbdev->dev)
2050                 drm_fb_helper_unregister_fbi(fb_helper);
2051 
2052         if (fb_helper->fbdev && fb_helper->fbdev->fbdefio) {
2053                 fb_deferred_io_cleanup(fb_helper->fbdev);
2054                 kfree(fb_helper->fbdev->fbdefio);
2055                 fbops = fb_helper->fbdev->fbops;
2056         }
2057 
2058         drm_fb_helper_fini(fb_helper);
2059         kfree(fbops);
2060 
2061         if (fb_helper->fb)
2062                 drm_framebuffer_remove(fb_helper->fb);
2063 }
2064 EXPORT_SYMBOL(drm_fb_helper_fbdev_teardown);
2065 
2066 /**
2067  * drm_fb_helper_lastclose - DRM driver lastclose helper for fbdev emulation
2068  * @dev: DRM device
2069  *
2070  * This function can be used as the &drm_driver->lastclose callback for drivers
2071  * that only need to call drm_fb_helper_restore_fbdev_mode_unlocked().
2072  */
2073 void drm_fb_helper_lastclose(struct drm_device *dev)
2074 {
2075         drm_fb_helper_restore_fbdev_mode_unlocked(dev->fb_helper);
2076 }
2077 EXPORT_SYMBOL(drm_fb_helper_lastclose);
2078 
2079 /**
2080  * drm_fb_helper_output_poll_changed - DRM mode config \.output_poll_changed
2081  *                                     helper for fbdev emulation
2082  * @dev: DRM device
2083  *
2084  * This function can be used as the
2085  * &drm_mode_config_funcs.output_poll_changed callback for drivers that only
2086  * need to call drm_fb_helper_hotplug_event().
2087  */
2088 void drm_fb_helper_output_poll_changed(struct drm_device *dev)
2089 {
2090         drm_fb_helper_hotplug_event(dev->fb_helper);
2091 }
2092 EXPORT_SYMBOL(drm_fb_helper_output_poll_changed);
2093 
2094 /* @user: 1=userspace, 0=fbcon */
2095 static int drm_fbdev_fb_open(struct fb_info *info, int user)
2096 {
2097         struct drm_fb_helper *fb_helper = info->par;
2098 
2099         /* No need to take a ref for fbcon because it unbinds on unregister */
2100         if (user && !try_module_get(fb_helper->dev->driver->fops->owner))
2101                 return -ENODEV;
2102 
2103         return 0;
2104 }
2105 
2106 static int drm_fbdev_fb_release(struct fb_info *info, int user)
2107 {
2108         struct drm_fb_helper *fb_helper = info->par;
2109 
2110         if (user)
2111                 module_put(fb_helper->dev->driver->fops->owner);
2112 
2113         return 0;
2114 }
2115 
2116 static void drm_fbdev_cleanup(struct drm_fb_helper *fb_helper)
2117 {
2118         struct fb_info *fbi = fb_helper->fbdev;
2119         struct fb_ops *fbops = NULL;
2120         void *shadow = NULL;
2121 
2122         if (!fb_helper->dev)
2123                 return;
2124 
2125         if (fbi && fbi->fbdefio) {
2126                 fb_deferred_io_cleanup(fbi);
2127                 shadow = fbi->screen_buffer;
2128                 fbops = fbi->fbops;
2129         }
2130 
2131         drm_fb_helper_fini(fb_helper);
2132 
2133         if (shadow) {
2134                 vfree(shadow);
2135                 kfree(fbops);
2136         }
2137 
2138         drm_client_framebuffer_delete(fb_helper->buffer);
2139 }
2140 
2141 static void drm_fbdev_release(struct drm_fb_helper *fb_helper)
2142 {
2143         drm_fbdev_cleanup(fb_helper);
2144         drm_client_release(&fb_helper->client);
2145         kfree(fb_helper);
2146 }
2147 
2148 /*
2149  * fb_ops.fb_destroy is called by the last put_fb_info() call at the end of
2150  * unregister_framebuffer() or fb_release().
2151  */
2152 static void drm_fbdev_fb_destroy(struct fb_info *info)
2153 {
2154         drm_fbdev_release(info->par);
2155 }
2156 
2157 static int drm_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
2158 {
2159         struct drm_fb_helper *fb_helper = info->par;
2160 
2161         if (fb_helper->dev->driver->gem_prime_mmap)
2162                 return fb_helper->dev->driver->gem_prime_mmap(fb_helper->buffer->gem, vma);
2163         else
2164                 return -ENODEV;
2165 }
2166 
2167 static struct fb_ops drm_fbdev_fb_ops = {
2168         .owner          = THIS_MODULE,
2169         DRM_FB_HELPER_DEFAULT_OPS,
2170         .fb_open        = drm_fbdev_fb_open,
2171         .fb_release     = drm_fbdev_fb_release,
2172         .fb_destroy     = drm_fbdev_fb_destroy,
2173         .fb_mmap        = drm_fbdev_fb_mmap,
2174         .fb_read        = drm_fb_helper_sys_read,
2175         .fb_write       = drm_fb_helper_sys_write,
2176         .fb_fillrect    = drm_fb_helper_sys_fillrect,
2177         .fb_copyarea    = drm_fb_helper_sys_copyarea,
2178         .fb_imageblit   = drm_fb_helper_sys_imageblit,
2179 };
2180 
2181 static struct fb_deferred_io drm_fbdev_defio = {
2182         .delay          = HZ / 20,
2183         .deferred_io    = drm_fb_helper_deferred_io,
2184 };
2185 
2186 /**
2187  * drm_fb_helper_generic_probe - Generic fbdev emulation probe helper
2188  * @fb_helper: fbdev helper structure
2189  * @sizes: describes fbdev size and scanout surface size
2190  *
2191  * This function uses the client API to create a framebuffer backed by a dumb buffer.
2192  *
2193  * The _sys_ versions are used for &fb_ops.fb_read, fb_write, fb_fillrect,
2194  * fb_copyarea, fb_imageblit.
2195  *
2196  * Returns:
2197  * Zero on success or negative error code on failure.
2198  */
2199 int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
2200                                 struct drm_fb_helper_surface_size *sizes)
2201 {
2202         struct drm_client_dev *client = &fb_helper->client;
2203         struct drm_client_buffer *buffer;
2204         struct drm_framebuffer *fb;
2205         struct fb_info *fbi;
2206         u32 format;
2207         void *vaddr;
2208 
2209         DRM_DEBUG_KMS("surface width(%d), height(%d) and bpp(%d)\n",
2210                       sizes->surface_width, sizes->surface_height,
2211                       sizes->surface_bpp);
2212 
2213         format = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);
2214         buffer = drm_client_framebuffer_create(client, sizes->surface_width,
2215                                                sizes->surface_height, format);
2216         if (IS_ERR(buffer))
2217                 return PTR_ERR(buffer);
2218 
2219         fb_helper->buffer = buffer;
2220         fb_helper->fb = buffer->fb;
2221         fb = buffer->fb;
2222 
2223         fbi = drm_fb_helper_alloc_fbi(fb_helper);
2224         if (IS_ERR(fbi))
2225                 return PTR_ERR(fbi);
2226 
2227         fbi->fbops = &drm_fbdev_fb_ops;
2228         fbi->screen_size = fb->height * fb->pitches[0];
2229         fbi->fix.smem_len = fbi->screen_size;
2230 
2231         drm_fb_helper_fill_info(fbi, fb_helper, sizes);
2232 
2233         if (drm_fbdev_use_shadow_fb(fb_helper)) {
2234                 struct fb_ops *fbops;
2235                 void *shadow;
2236 
2237                 /*
2238                  * fb_deferred_io_cleanup() clears &fbops->fb_mmap so a per
2239                  * instance version is necessary.
2240                  */
2241                 fbops = kzalloc(sizeof(*fbops), GFP_KERNEL);
2242                 shadow = vzalloc(fbi->screen_size);
2243                 if (!fbops || !shadow) {
2244                         kfree(fbops);
2245                         vfree(shadow);
2246                         return -ENOMEM;
2247                 }
2248 
2249                 *fbops = *fbi->fbops;
2250                 fbi->fbops = fbops;
2251                 fbi->screen_buffer = shadow;
2252                 fbi->fbdefio = &drm_fbdev_defio;
2253 
2254                 fb_deferred_io_init(fbi);
2255         } else {
2256                 /* buffer is mapped for HW framebuffer */
2257                 vaddr = drm_client_buffer_vmap(fb_helper->buffer);
2258                 if (IS_ERR(vaddr))
2259                         return PTR_ERR(vaddr);
2260 
2261                 fbi->screen_buffer = vaddr;
2262                 /* Shamelessly leak the physical address to user-space */
2263 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
2264                 if (drm_leak_fbdev_smem && fbi->fix.smem_start == 0)
2265                         fbi->fix.smem_start =
2266                                 page_to_phys(virt_to_page(fbi->screen_buffer));
2267 #endif
2268         }
2269 
2270         return 0;
2271 }
2272 EXPORT_SYMBOL(drm_fb_helper_generic_probe);
2273 
2274 static const struct drm_fb_helper_funcs drm_fb_helper_generic_funcs = {
2275         .fb_probe = drm_fb_helper_generic_probe,
2276 };
2277 
2278 static void drm_fbdev_client_unregister(struct drm_client_dev *client)
2279 {
2280         struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
2281 
2282         if (fb_helper->fbdev)
2283                 /* drm_fbdev_fb_destroy() takes care of cleanup */
2284                 drm_fb_helper_unregister_fbi(fb_helper);
2285         else
2286                 drm_fbdev_release(fb_helper);
2287 }
2288 
2289 static int drm_fbdev_client_restore(struct drm_client_dev *client)
2290 {
2291         drm_fb_helper_lastclose(client->dev);
2292 
2293         return 0;
2294 }
2295 
2296 static int drm_fbdev_client_hotplug(struct drm_client_dev *client)
2297 {
2298         struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
2299         struct drm_device *dev = client->dev;
2300         int ret;
2301 
2302         /* Setup is not retried if it has failed */
2303         if (!fb_helper->dev && fb_helper->funcs)
2304                 return 0;
2305 
2306         if (dev->fb_helper)
2307                 return drm_fb_helper_hotplug_event(dev->fb_helper);
2308 
2309         if (!dev->mode_config.num_connector) {
2310                 DRM_DEV_DEBUG(dev->dev, "No connectors found, will not create framebuffer!\n");
2311                 return 0;
2312         }
2313 
2314         drm_fb_helper_prepare(dev, fb_helper, &drm_fb_helper_generic_funcs);
2315 
2316         ret = drm_fb_helper_init(dev, fb_helper, 0);
2317         if (ret)
2318                 goto err;
2319 
2320         if (!drm_drv_uses_atomic_modeset(dev))
2321                 drm_helper_disable_unused_functions(dev);
2322 
2323         ret = drm_fb_helper_initial_config(fb_helper, fb_helper->preferred_bpp);
2324         if (ret)
2325                 goto err_cleanup;
2326 
2327         return 0;
2328 
2329 err_cleanup:
2330         drm_fbdev_cleanup(fb_helper);
2331 err:
2332         fb_helper->dev = NULL;
2333         fb_helper->fbdev = NULL;
2334 
2335         DRM_DEV_ERROR(dev->dev, "fbdev: Failed to setup generic emulation (ret=%d)\n", ret);
2336 
2337         return ret;
2338 }
2339 
2340 static const struct drm_client_funcs drm_fbdev_client_funcs = {
2341         .owner          = THIS_MODULE,
2342         .unregister     = drm_fbdev_client_unregister,
2343         .restore        = drm_fbdev_client_restore,
2344         .hotplug        = drm_fbdev_client_hotplug,
2345 };
2346 
2347 /**
2348  * drm_fbdev_generic_setup() - Setup generic fbdev emulation
2349  * @dev: DRM device
2350  * @preferred_bpp: Preferred bits per pixel for the device.
2351  *                 @dev->mode_config.preferred_depth is used if this is zero.
2352  *
2353  * This function sets up generic fbdev emulation for drivers that supports
2354  * dumb buffers with a virtual address and that can be mmap'ed. If the driver
2355  * does not support these functions, it could use drm_fb_helper_fbdev_setup().
2356  *
2357  * Restore, hotplug events and teardown are all taken care of. Drivers that do
2358  * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves.
2359  * Simple drivers might use drm_mode_config_helper_suspend().
2360  *
2361  * Drivers that set the dirty callback on their framebuffer will get a shadow
2362  * fbdev buffer that is blitted onto the real buffer. This is done in order to
2363  * make deferred I/O work with all kinds of buffers.
2364  *
2365  * This function is safe to call even when there are no connectors present.
2366  * Setup will be retried on the next hotplug event.
2367  *
2368  * The fbdev is destroyed by drm_dev_unregister().
2369  *
2370  * Returns:
2371  * Zero on success or negative error code on failure.
2372  */
2373 int drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp)
2374 {
2375         struct drm_fb_helper *fb_helper;
2376         int ret;
2377 
2378         WARN(dev->fb_helper, "fb_helper is already set!\n");
2379 
2380         if (!drm_fbdev_emulation)
2381                 return 0;
2382 
2383         fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
2384         if (!fb_helper)
2385                 return -ENOMEM;
2386 
2387         ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_client_funcs);
2388         if (ret) {
2389                 kfree(fb_helper);
2390                 DRM_DEV_ERROR(dev->dev, "Failed to register client: %d\n", ret);
2391                 return ret;
2392         }
2393 
2394         if (!preferred_bpp)
2395                 preferred_bpp = dev->mode_config.preferred_depth;
2396         if (!preferred_bpp)
2397                 preferred_bpp = 32;
2398         fb_helper->preferred_bpp = preferred_bpp;
2399 
2400         ret = drm_fbdev_client_hotplug(&fb_helper->client);
2401         if (ret)
2402                 DRM_DEV_DEBUG(dev->dev, "client hotplug ret=%d\n", ret);
2403 
2404         drm_client_register(&fb_helper->client);
2405 
2406         return 0;
2407 }
2408 EXPORT_SYMBOL(drm_fbdev_generic_setup);
2409 
2410 /* The Kconfig DRM_KMS_HELPER selects FRAMEBUFFER_CONSOLE (if !EXPERT)
2411  * but the module doesn't depend on any fb console symbols.  At least
2412  * attempt to load fbcon to avoid leaving the system without a usable console.
2413  */
2414 int __init drm_fb_helper_modinit(void)
2415 {
2416 #if defined(CONFIG_FRAMEBUFFER_CONSOLE_MODULE) && !defined(CONFIG_EXPERT)
2417         const char name[] = "fbcon";
2418         struct module *fbcon;
2419 
2420         mutex_lock(&module_mutex);
2421         fbcon = find_module(name);
2422         mutex_unlock(&module_mutex);
2423 
2424         if (!fbcon)
2425                 request_module_nowait(name);
2426 #endif
2427         return 0;
2428 }
2429 EXPORT_SYMBOL(drm_fb_helper_modinit);