drivers/video/msm/msm_fb.c

   1 /* drivers/video/msm/msm_fb.c
   2  *
   3  * Core MSM framebuffer driver.
   4  *
   5  * Copyright (C) 2007 Google Incorporated
   6  *
   7  * This software is licensed under the terms of the GNU General Public
   8  * License version 2, as published by the Free Software Foundation, and
   9  * may be copied, distributed, and modified under those terms.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #include <linux/platform_device.h>
  18 #include <linux/module.h>
  19 #include <linux/fb.h>
  20 #include <linux/slab.h>
  21 #include <linux/delay.h>
  22
  23 #include <linux/freezer.h>
  24 #include <linux/wait.h>
  25 #include <linux/msm_mdp.h>
  26 #include <linux/io.h>
  27 #include <linux/uaccess.h>
  28 #include <linux/platform_data/video-msm_fb.h>
  29 #include <linux/workqueue.h>
  30 #include <linux/clk.h>
  31 #include <linux/debugfs.h>
  32 #include <linux/dma-mapping.h>
  33
  34 #define PRINT_FPS 0
  35 #define PRINT_BLIT_TIME 0
  36
  37 #define SLEEPING 0x4
  38 #define UPDATING 0x3
  39 #define FULL_UPDATE_DONE 0x2
  40 #define WAKING 0x1
  41 #define AWAKE 0x0
  42
  43 #define NONE 0
  44 #define SUSPEND_RESUME 0x1
  45 #define FPS 0x2
  46 #define BLIT_TIME 0x4
  47 #define SHOW_UPDATES 0x8
  48
  49 #define DLOG(mask, fmt, args...) \
  50 do { \
  51         if (msmfb_debug_mask & mask) \
  52                 printk(KERN_INFO "msmfb: "fmt, ##args); \
  53 } while (0)
  54
  55 static int msmfb_debug_mask;
  56 module_param_named(msmfb_debug_mask, msmfb_debug_mask, int,
  57                    S_IRUGO | S_IWUSR | S_IWGRP);
  58
  59 struct mdp_device *mdp;
  60
  61 struct msmfb_info {
  62         struct fb_info *fb;
  63         struct msm_panel_data *panel;
  64         int xres;
  65         int yres;
  66         unsigned output_format;
  67         unsigned yoffset;
  68         unsigned frame_requested;
  69         unsigned frame_done;
  70         int sleeping;
  71         unsigned update_frame;
  72         struct {
  73                 int left;
  74                 int top;
  75                 int eright; /* exclusive */
  76                 int ebottom; /* exclusive */
  77         } update_info;
  78         char *black;
  79
  80         spinlock_t update_lock;
  81         struct mutex panel_init_lock;
  82         wait_queue_head_t frame_wq;
  83         struct work_struct resume_work;
  84         struct msmfb_callback dma_callback;
  85         struct msmfb_callback vsync_callback;
  86         struct hrtimer fake_vsync;
  87         ktime_t vsync_request_time;
  88 };
  89
  90 static int msmfb_open(struct fb_info *info, int user)
  91 {
  92         return 0;
  93 }
  94
  95 static int msmfb_release(struct fb_info *info, int user)
  96 {
  97         return 0;
  98 }
  99
 100 /* Called from dma interrupt handler, must not sleep */
 101 static void msmfb_handle_dma_interrupt(struct msmfb_callback *callback)
 102 {
 103         unsigned long irq_flags;
 104         struct msmfb_info *msmfb  = container_of(callback, struct msmfb_info,
 105                                                dma_callback);
 106
 107         spin_lock_irqsave(&msmfb->update_lock, irq_flags);
 108         msmfb->frame_done = msmfb->frame_requested;
 109         if (msmfb->sleeping == UPDATING &&
 110             msmfb->frame_done == msmfb->update_frame) {
 111                 DLOG(SUSPEND_RESUME, "full update completed\n");
 112                 schedule_work(&msmfb->resume_work);
 113         }
 114         spin_unlock_irqrestore(&msmfb->update_lock, irq_flags);
 115         wake_up(&msmfb->frame_wq);
 116 }
 117
 118 static int msmfb_start_dma(struct msmfb_info *msmfb)
 119 {
 120         uint32_t x, y, w, h;
 121         unsigned addr;
 122         unsigned long irq_flags;
 123         uint32_t yoffset;
 124         s64 time_since_request;
 125         struct msm_panel_data *panel = msmfb->panel;
 126
 127         spin_lock_irqsave(&msmfb->update_lock, irq_flags);
 128         time_since_request = ktime_to_ns(ktime_sub(ktime_get(),
 129                              msmfb->vsync_request_time));
 130         if (time_since_request > 20 * NSEC_PER_MSEC) {
 131                 uint32_t us;
 132                 us = do_div(time_since_request, NSEC_PER_MSEC) / NSEC_PER_USEC;
 133                 printk(KERN_WARNING "msmfb_start_dma %lld.%03u ms after vsync "
 134                         "request\n", time_since_request, us);
 135         }
 136         if (msmfb->frame_done == msmfb->frame_requested) {
 137                 spin_unlock_irqrestore(&msmfb->update_lock, irq_flags);
 138                 return -1;
 139         }
 140         if (msmfb->sleeping == SLEEPING) {
 141                 DLOG(SUSPEND_RESUME, "tried to start dma while asleep\n");
 142                 spin_unlock_irqrestore(&msmfb->update_lock, irq_flags);
 143                 return -1;
 144         }
 145         x = msmfb->update_info.left;
 146         y = msmfb->update_info.top;
 147         w = msmfb->update_info.eright - x;
 148         h = msmfb->update_info.ebottom - y;
 149         yoffset = msmfb->yoffset;
 150         msmfb->update_info.left = msmfb->xres + 1;
 151         msmfb->update_info.top = msmfb->yres + 1;
 152         msmfb->update_info.eright = 0;
 153         msmfb->update_info.ebottom = 0;
 154         if (unlikely(w > msmfb->xres || h > msmfb->yres ||
 155                      w == 0 || h == 0)) {
 156                 printk(KERN_INFO "invalid update: %d %d %d "
 157                                 "%d\n", x, y, w, h);
 158                 msmfb->frame_done = msmfb->frame_requested;
 159                 goto error;
 160         }
 161         spin_unlock_irqrestore(&msmfb->update_lock, irq_flags);
 162
 163         addr = ((msmfb->xres * (yoffset + y) + x) * 2);
 164         mdp->dma(mdp, addr + msmfb->fb->fix.smem_start,
 165                  msmfb->xres * 2, w, h, x, y, &msmfb->dma_callback,
 166                  panel->interface_type);
 167         return 0;
 168 error:
 169         spin_unlock_irqrestore(&msmfb->update_lock, irq_flags);
 170         /* some clients need to clear their vsync interrupt */
 171         if (panel->clear_vsync)
 172                 panel->clear_vsync(panel);
 173         wake_up(&msmfb->frame_wq);
 174         return 0;
 175 }
 176
 177 /* Called from esync interrupt handler, must not sleep */
 178 static void msmfb_handle_vsync_interrupt(struct msmfb_callback *callback)
 179 {
 180         struct msmfb_info *msmfb = container_of(callback, struct msmfb_info,
 181                                                vsync_callback);
 182         msmfb_start_dma(msmfb);
 183 }
 184
 185 static enum hrtimer_restart msmfb_fake_vsync(struct hrtimer *timer)
 186 {
 187         struct msmfb_info *msmfb  = container_of(timer, struct msmfb_info,
 188                                                fake_vsync);
 189         msmfb_start_dma(msmfb);
 190         return HRTIMER_NORESTART;
 191 }
 192
 193 static void msmfb_pan_update(struct fb_info *info, uint32_t left, uint32_t top,
 194                              uint32_t eright, uint32_t ebottom,
 195                              uint32_t yoffset, int pan_display)
 196 {
 197         struct msmfb_info *msmfb = info->par;
 198         struct msm_panel_data *panel = msmfb->panel;
 199         unsigned long irq_flags;
 200         int sleeping;
 201         int retry = 1;
 202
 203         DLOG(SHOW_UPDATES, "update %d %d %d %d %d %d\n",
 204                 left, top, eright, ebottom, yoffset, pan_display);
 205 restart:
 206         spin_lock_irqsave(&msmfb->update_lock, irq_flags);
 207
 208         /* if we are sleeping, on a pan_display wait 10ms (to throttle back
 209          * drawing otherwise return */
 210         if (msmfb->sleeping == SLEEPING) {
 211                 DLOG(SUSPEND_RESUME, "drawing while asleep\n");
 212                 spin_unlock_irqrestore(&msmfb->update_lock, irq_flags);
 213                 if (pan_display)
 214                         wait_event_interruptible_timeout(msmfb->frame_wq,
 215                                 msmfb->sleeping != SLEEPING, HZ/10);
 216                 return;
 217         }
 218
 219         sleeping = msmfb->sleeping;
 220         /* on a full update, if the last frame has not completed, wait for it */
 221         if ((pan_display && msmfb->frame_requested != msmfb->frame_done) ||
 222                             sleeping == UPDATING) {
 223                 int ret;
 224                 spin_unlock_irqrestore(&msmfb->update_lock, irq_flags);
 225                 ret = wait_event_interruptible_timeout(msmfb->frame_wq,
 226                         msmfb->frame_done == msmfb->frame_requested &&
 227                         msmfb->sleeping != UPDATING, 5 * HZ);
 228                 if (ret <= 0 && (msmfb->frame_requested != msmfb->frame_done ||
 229                                  msmfb->sleeping == UPDATING)) {
 230                         if (retry && panel->request_vsync &&
 231                             (sleeping == AWAKE)) {
 232                                 panel->request_vsync(panel,
 233                                         &msmfb->vsync_callback);
 234                                 retry = 0;
 235                                 printk(KERN_WARNING "msmfb_pan_display timeout "
 236                                         "rerequest vsync\n");
 237                         } else {
 238                                 printk(KERN_WARNING "msmfb_pan_display timeout "
 239                                         "waiting for frame start, %d %d\n",
 240                                         msmfb->frame_requested,
 241                                         msmfb->frame_done);
 242                                 return;
 243                         }
 244                 }
 245                 goto restart;
 246         }
 247
 248
 249         msmfb->frame_requested++;
 250         /* if necessary, update the y offset, if this is the
 251          * first full update on resume, set the sleeping state */
 252         if (pan_display) {
 253                 msmfb->yoffset = yoffset;
 254                 if (left == 0 && top == 0 && eright == info->var.xres &&
 255                     ebottom == info->var.yres) {
 256                         if (sleeping == WAKING) {
 257                                 msmfb->update_frame = msmfb->frame_requested;
 258                                 DLOG(SUSPEND_RESUME, "full update starting\n");
 259                                 msmfb->sleeping = UPDATING;
 260                         }
 261                 }
 262         }
 263
 264         /* set the update request */
 265         if (left < msmfb->update_info.left)
 266                 msmfb->update_info.left = left;
 267         if (top < msmfb->update_info.top)
 268                 msmfb->update_info.top = top;
 269         if (eright > msmfb->update_info.eright)
 270                 msmfb->update_info.eright = eright;
 271         if (ebottom > msmfb->update_info.ebottom)
 272                 msmfb->update_info.ebottom = ebottom;
 273         DLOG(SHOW_UPDATES, "update queued %d %d %d %d %d\n",
 274                 msmfb->update_info.left, msmfb->update_info.top,
 275                 msmfb->update_info.eright, msmfb->update_info.ebottom,
 276                 msmfb->yoffset);
 277         spin_unlock_irqrestore(&msmfb->update_lock, irq_flags);
 278
 279         /* if the panel is all the way on wait for vsync, otherwise sleep
 280          * for 16 ms (long enough for the dma to panel) and then begin dma */
 281         msmfb->vsync_request_time = ktime_get();
 282         if (panel->request_vsync && (sleeping == AWAKE)) {
 283                 panel->request_vsync(panel, &msmfb->vsync_callback);
 284         } else {
 285                 if (!hrtimer_active(&msmfb->fake_vsync)) {
 286                         hrtimer_start(&msmfb->fake_vsync,
 287                                       ktime_set(0, NSEC_PER_SEC/60),
 288                                       HRTIMER_MODE_REL);
 289                 }
 290         }
 291 }
 292
 293 static void msmfb_update(struct fb_info *info, uint32_t left, uint32_t top,
 294                          uint32_t eright, uint32_t ebottom)
 295 {
 296         msmfb_pan_update(info, left, top, eright, ebottom, 0, 0);
 297 }
 298
 299 static void power_on_panel(struct work_struct *work)
 300 {
 301         struct msmfb_info *msmfb =
 302                 container_of(work, struct msmfb_info, resume_work);
 303         struct msm_panel_data *panel = msmfb->panel;
 304         unsigned long irq_flags;
 305
 306         mutex_lock(&msmfb->panel_init_lock);
 307         DLOG(SUSPEND_RESUME, "turning on panel\n");
 308         if (msmfb->sleeping == UPDATING) {
 309                 if (panel->unblank(panel)) {
 310                         printk(KERN_INFO "msmfb: panel unblank failed,"
 311                                "not starting drawing\n");
 312                         goto error;
 313                 }
 314                 spin_lock_irqsave(&msmfb->update_lock, irq_flags);
 315                 msmfb->sleeping = AWAKE;
 316                 wake_up(&msmfb->frame_wq);
 317                 spin_unlock_irqrestore(&msmfb->update_lock, irq_flags);
 318         }
 319 error:
 320         mutex_unlock(&msmfb->panel_init_lock);
 321 }
 322
 323
 324 static int msmfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
 325 {
 326         if ((var->xres != info->var.xres) ||
 327             (var->yres != info->var.yres) ||
 328             (var->xres_virtual != info->var.xres_virtual) ||
 329             (var->yres_virtual != info->var.yres_virtual) ||
 330             (var->xoffset != info->var.xoffset) ||
 331             (var->bits_per_pixel != info->var.bits_per_pixel) ||
 332             (var->grayscale != info->var.grayscale))
 333                  return -EINVAL;
 334         return 0;
 335 }
 336
 337 int msmfb_pan_display(struct fb_var_screeninfo *var, struct fb_info *info)
 338 {
 339         struct msmfb_info *msmfb = info->par;
 340         struct msm_panel_data *panel = msmfb->panel;
 341
 342         /* "UPDT" */
 343         if ((panel->caps & MSMFB_CAP_PARTIAL_UPDATES) &&
 344             (var->reserved[0] == 0x54445055)) {
 345                 msmfb_pan_update(info, var->reserved[1] & 0xffff,
 346                                  var->reserved[1] >> 16,
 347                                  var->reserved[2] & 0xffff,
 348                                  var->reserved[2] >> 16, var->yoffset, 1);
 349         } else {
 350                 msmfb_pan_update(info, 0, 0, info->var.xres, info->var.yres,
 351                                  var->yoffset, 1);
 352         }
 353         return 0;
 354 }
 355
 356 static void msmfb_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
 357 {
 358         cfb_fillrect(p, rect);
 359         msmfb_update(p, rect->dx, rect->dy, rect->dx + rect->width,
 360                      rect->dy + rect->height);
 361 }
 362
 363 static void msmfb_copyarea(struct fb_info *p, const struct fb_copyarea *area)
 364 {
 365         cfb_copyarea(p, area);
 366         msmfb_update(p, area->dx, area->dy, area->dx + area->width,
 367                      area->dy + area->height);
 368 }
 369
 370 static void msmfb_imageblit(struct fb_info *p, const struct fb_image *image)
 371 {
 372         cfb_imageblit(p, image);
 373         msmfb_update(p, image->dx, image->dy, image->dx + image->width,
 374                      image->dy + image->height);
 375 }
 376
 377
 378 static int msmfb_blit(struct fb_info *info,
 379                       void __user *p)
 380 {
 381         struct mdp_blit_req req;
 382         struct mdp_blit_req_list req_list;
 383         int i;
 384         int ret;
 385
 386         if (copy_from_user(&req_list, p, sizeof(req_list)))
 387                 return -EFAULT;
 388
 389         for (i = 0; i < req_list.count; i++) {
 390                 struct mdp_blit_req_list *list =
 391                         (struct mdp_blit_req_list *)p;
 392                 if (copy_from_user(&req, &list->req[i], sizeof(req)))
 393                         return -EFAULT;
 394                 ret = mdp->blit(mdp, info, &req);
 395                 if (ret)
 396                         return ret;
 397         }
 398         return 0;
 399 }
 400
 401
 402 DEFINE_MUTEX(mdp_ppp_lock);
 403
 404 static int msmfb_ioctl(struct fb_info *p, unsigned int cmd, unsigned long arg)
 405 {
 406         void __user *argp = (void __user *)arg;
 407         int ret;
 408
 409         switch (cmd) {
 410         case MSMFB_GRP_DISP:
 411                 mdp->set_grp_disp(mdp, arg);
 412                 break;
 413         case MSMFB_BLIT:
 414                 ret = msmfb_blit(p, argp);
 415                 if (ret)
 416                         return ret;
 417                 break;
 418         default:
 419                         printk(KERN_INFO "msmfb unknown ioctl: %d\n", cmd);
 420                         return -EINVAL;
 421         }
 422         return 0;
 423 }
 424
 425 static struct fb_ops msmfb_ops = {
 426         .owner = THIS_MODULE,
 427         .fb_open = msmfb_open,
 428         .fb_release = msmfb_release,
 429         .fb_check_var = msmfb_check_var,
 430         .fb_pan_display = msmfb_pan_display,
 431         .fb_fillrect = msmfb_fillrect,
 432         .fb_copyarea = msmfb_copyarea,
 433         .fb_imageblit = msmfb_imageblit,
 434         .fb_ioctl = msmfb_ioctl,
 435 };
 436
 437 static unsigned PP[16];
 438
 439
 440
 441 #define BITS_PER_PIXEL 16
 442
 443 static void setup_fb_info(struct msmfb_info *msmfb)
 444 {
 445         struct fb_info *fb_info = msmfb->fb;
 446         int r;
 447
 448         /* finish setting up the fb_info struct */
 449         strncpy(fb_info->fix.id, "msmfb", 16);
 450         fb_info->fix.ypanstep = 1;
 451
 452         fb_info->fbops = &msmfb_ops;
 453         fb_info->flags = FBINFO_DEFAULT;
 454
 455         fb_info->fix.type = FB_TYPE_PACKED_PIXELS;
 456         fb_info->fix.visual = FB_VISUAL_TRUECOLOR;
 457         fb_info->fix.line_length = msmfb->xres * 2;
 458
 459         fb_info->var.xres = msmfb->xres;
 460         fb_info->var.yres = msmfb->yres;
 461         fb_info->var.width = msmfb->panel->fb_data->width;
 462         fb_info->var.height = msmfb->panel->fb_data->height;
 463         fb_info->var.xres_virtual = msmfb->xres;
 464         fb_info->var.yres_virtual = msmfb->yres * 2;
 465         fb_info->var.bits_per_pixel = BITS_PER_PIXEL;
 466         fb_info->var.accel_flags = 0;
 467
 468         fb_info->var.yoffset = 0;
 469
 470         if (msmfb->panel->caps & MSMFB_CAP_PARTIAL_UPDATES) {
 471                 /*
 472                  * Set the param in the fixed screen, so userspace can't
 473                  * change it. This will be used to check for the
 474                  * capability.
 475                  */
 476                 fb_info->fix.reserved[0] = 0x5444;
 477                 fb_info->fix.reserved[1] = 0x5055;
 478
 479                 /*
 480                  * This preloads the value so that if userspace doesn't
 481                  * change it, it will be a full update
 482                  */
 483                 fb_info->var.reserved[0] = 0x54445055;
 484                 fb_info->var.reserved[1] = 0;
 485                 fb_info->var.reserved[2] = (uint16_t)msmfb->xres |
 486                                            ((uint32_t)msmfb->yres << 16);
 487         }
 488
 489         fb_info->var.red.offset = 11;
 490         fb_info->var.red.length = 5;
 491         fb_info->var.red.msb_right = 0;
 492         fb_info->var.green.offset = 5;
 493         fb_info->var.green.length = 6;
 494         fb_info->var.green.msb_right = 0;
 495         fb_info->var.blue.offset = 0;
 496         fb_info->var.blue.length = 5;
 497         fb_info->var.blue.msb_right = 0;
 498
 499         r = fb_alloc_cmap(&fb_info->cmap, 16, 0);
 500         fb_info->pseudo_palette = PP;
 501
 502         PP[0] = 0;
 503         for (r = 1; r < 16; r++)
 504                 PP[r] = 0xffffffff;
 505 }
 506
 507 static int setup_fbmem(struct msmfb_info *msmfb, struct platform_device *pdev)
 508 {
 509         struct fb_info *fb = msmfb->fb;
 510         struct resource *resource;
 511         unsigned long size = msmfb->xres * msmfb->yres *
 512                              (BITS_PER_PIXEL >> 3) * 2;
 513         unsigned char *fbram;
 514
 515         /* board file might have attached a resource describing an fb */
 516         resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 517         if (!resource)
 518                 return -EINVAL;
 519
 520         /* check the resource is large enough to fit the fb */
 521         if (resource->end - resource->start < size) {
 522                 printk(KERN_ERR "allocated resource is too small for "
 523                                 "fb\n");
 524                 return -ENOMEM;
 525         }
 526         fb->fix.smem_start = resource->start;
 527         fb->fix.smem_len = resource_size(resource);
 528         fbram = ioremap(resource->start, resource_size(resource));
 529         if (fbram == NULL) {
 530                 printk(KERN_ERR "msmfb: cannot allocate fbram!\n");
 531                 return -ENOMEM;
 532         }
 533         fb->screen_base = fbram;
 534         return 0;
 535 }
 536
 537 static int msmfb_probe(struct platform_device *pdev)
 538 {
 539         struct fb_info *fb;
 540         struct msmfb_info *msmfb;
 541         struct msm_panel_data *panel = pdev->dev.platform_data;
 542         int ret;
 543
 544         if (!panel) {
 545                 pr_err("msmfb_probe: no platform data\n");
 546                 return -EINVAL;
 547         }
 548         if (!panel->fb_data) {
 549                 pr_err("msmfb_probe: no fb_data\n");
 550                 return -EINVAL;
 551         }
 552
 553         fb = framebuffer_alloc(sizeof(struct msmfb_info), &pdev->dev);
 554         if (!fb)
 555                 return -ENOMEM;
 556         msmfb = fb->par;
 557         msmfb->fb = fb;
 558         msmfb->panel = panel;
 559         msmfb->xres = panel->fb_data->xres;
 560         msmfb->yres = panel->fb_data->yres;
 561
 562         ret = setup_fbmem(msmfb, pdev);
 563         if (ret)
 564                 goto error_setup_fbmem;
 565
 566         setup_fb_info(msmfb);
 567
 568         spin_lock_init(&msmfb->update_lock);
 569         mutex_init(&msmfb->panel_init_lock);
 570         init_waitqueue_head(&msmfb->frame_wq);
 571         INIT_WORK(&msmfb->resume_work, power_on_panel);
 572         msmfb->black = kzalloc(msmfb->fb->var.bits_per_pixel*msmfb->xres,
 573                                GFP_KERNEL);
 574
 575         printk(KERN_INFO "msmfb_probe() installing %d x %d panel\n",
 576                msmfb->xres, msmfb->yres);
 577
 578         msmfb->dma_callback.func = msmfb_handle_dma_interrupt;
 579         msmfb->vsync_callback.func = msmfb_handle_vsync_interrupt;
 580         hrtimer_init(&msmfb->fake_vsync, CLOCK_MONOTONIC,
 581                      HRTIMER_MODE_REL);
 582
 583
 584         msmfb->fake_vsync.function = msmfb_fake_vsync;
 585
 586         ret = register_framebuffer(fb);
 587         if (ret)
 588                 goto error_register_framebuffer;
 589
 590         msmfb->sleeping = WAKING;
 591
 592         return 0;
 593
 594 error_register_framebuffer:
 595         iounmap(fb->screen_base);
 596 error_setup_fbmem:
 597         framebuffer_release(msmfb->fb);
 598         return ret;
 599 }
 600
 601 static struct platform_driver msm_panel_driver = {
 602         /* need to write remove */
 603         .probe = msmfb_probe,
 604         .driver = {.name = "msm_panel"},
 605 };
 606
 607
 608 static int msmfb_add_mdp_device(struct device *dev,
 609                                 struct class_interface *class_intf)
 610 {
 611         /* might need locking if mulitple mdp devices */
 612         if (mdp)
 613                 return 0;
 614         mdp = container_of(dev, struct mdp_device, dev);
 615         return platform_driver_register(&msm_panel_driver);
 616 }
 617
 618 static void msmfb_remove_mdp_device(struct device *dev,
 619                                 struct class_interface *class_intf)
 620 {
 621         /* might need locking if mulitple mdp devices */
 622         if (dev != &mdp->dev)
 623                 return;
 624         platform_driver_unregister(&msm_panel_driver);
 625         mdp = NULL;
 626 }
 627
 628 static struct class_interface msm_fb_interface = {
 629         .add_dev = &msmfb_add_mdp_device,
 630         .remove_dev = &msmfb_remove_mdp_device,
 631 };
 632
 633 static int __init msmfb_init(void)
 634 {
 635         return register_mdp_client(&msm_fb_interface);
 636 }
 637
 638 module_init(msmfb_init);