drivers/staging/olpc_dcon/olpc_dcon.c

   1 /*
   2  * Mainly by David Woodhouse, somewhat modified by Jordan Crouse
   3  *
   4  * Copyright © 2006-2007  Red Hat, Inc.
   5  * Copyright © 2006-2007  Advanced Micro Devices, Inc.
   6  * Copyright © 2009       VIA Technology, Inc.
   7  * Copyright (c) 2010-2011  Andres Salomon <dilinger@queued.net>
   8  *
   9  * This program is free software.  You can redistribute it and/or
  10  * modify it under the terms of version 2 of the GNU General Public
  11  * License as published by the Free Software Foundation.
  12  */
  13
  14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15
  16 #include <linux/kernel.h>
  17 #include <linux/fb.h>
  18 #include <linux/console.h>
  19 #include <linux/i2c.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/pci.h>
  22 #include <linux/pci_ids.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/delay.h>
  25 #include <linux/module.h>
  26 #include <linux/backlight.h>
  27 #include <linux/device.h>
  28 #include <linux/uaccess.h>
  29 #include <linux/ctype.h>
  30 #include <linux/reboot.h>
  31 #include <linux/olpc-ec.h>
  32 #include <asm/tsc.h>
  33 #include <asm/olpc.h>
  34
  35 #include "olpc_dcon.h"
  36
  37 /* Module definitions */
  38
  39 static ushort resumeline = 898;
  40 module_param(resumeline, ushort, 0444);
  41
  42 static struct dcon_platform_data *pdata;
  43
  44 /* I2C structures */
  45
  46 /* Platform devices */
  47 static struct platform_device *dcon_device;
  48
  49 static unsigned short normal_i2c[] = { 0x0d, I2C_CLIENT_END };
  50
  51 static s32 dcon_write(struct dcon_priv *dcon, u8 reg, u16 val)
  52 {
  53         return i2c_smbus_write_word_data(dcon->client, reg, val);
  54 }
  55
  56 static s32 dcon_read(struct dcon_priv *dcon, u8 reg)
  57 {
  58         return i2c_smbus_read_word_data(dcon->client, reg);
  59 }
  60
  61 /* ===== API functions - these are called by a variety of users ==== */
  62
  63 static int dcon_hw_init(struct dcon_priv *dcon, int is_init)
  64 {
  65         uint16_t ver;
  66         int rc = 0;
  67
  68         ver = dcon_read(dcon, DCON_REG_ID);
  69         if ((ver >> 8) != 0xDC) {
  70                 pr_err("DCON ID not 0xDCxx: 0x%04x instead.\n", ver);
  71                 rc = -ENXIO;
  72                 goto err;
  73         }
  74
  75         if (is_init) {
  76                 pr_info("Discovered DCON version %x\n", ver & 0xFF);
  77                 rc = pdata->init(dcon);
  78                 if (rc != 0) {
  79                         pr_err("Unable to init.\n");
  80                         goto err;
  81                 }
  82         }
  83
  84         if (ver < 0xdc02) {
  85                 dev_err(&dcon->client->dev,
  86                                 "DCON v1 is unsupported, giving up..\n");
  87                 rc = -ENODEV;
  88                 goto err;
  89         }
  90
  91         /* SDRAM setup/hold time */
  92         dcon_write(dcon, 0x3a, 0xc040);
  93         dcon_write(dcon, DCON_REG_MEM_OPT_A, 0x0000);  /* clear option bits */
  94         dcon_write(dcon, DCON_REG_MEM_OPT_A,
  95                                 MEM_DLL_CLOCK_DELAY | MEM_POWER_DOWN);
  96         dcon_write(dcon, DCON_REG_MEM_OPT_B, MEM_SOFT_RESET);
  97
  98         /* Colour swizzle, AA, no passthrough, backlight */
  99         if (is_init) {
 100                 dcon->disp_mode = MODE_PASSTHRU | MODE_BL_ENABLE |
 101                                 MODE_CSWIZZLE | MODE_COL_AA;
 102         }
 103         dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
 104
 105
 106         /* Set the scanline to interrupt on during resume */
 107         dcon_write(dcon, DCON_REG_SCAN_INT, resumeline);
 108
 109 err:
 110         return rc;
 111 }
 112
 113 /*
 114  * The smbus doesn't always come back due to what is believed to be
 115  * hardware (power rail) bugs.  For older models where this is known to
 116  * occur, our solution is to attempt to wait for the bus to stabilize;
 117  * if it doesn't happen, cut power to the dcon, repower it, and wait
 118  * for the bus to stabilize.  Rinse, repeat until we have a working
 119  * smbus.  For newer models, we simply BUG(); we want to know if this
 120  * still happens despite the power fixes that have been made!
 121  */
 122 static int dcon_bus_stabilize(struct dcon_priv *dcon, int is_powered_down)
 123 {
 124         unsigned long timeout;
 125         u8 pm;
 126         int x;
 127
 128 power_up:
 129         if (is_powered_down) {
 130                 pm = 1;
 131                 x = olpc_ec_cmd(EC_DCON_POWER_MODE, &pm, 1, NULL, 0);
 132                 if (x) {
 133                         pr_warn("unable to force dcon to power up: %d!\n", x);
 134                         return x;
 135                 }
 136                 usleep_range(10000, 11000);  /* we'll be conservative */
 137         }
 138
 139         pdata->bus_stabilize_wiggle();
 140
 141         for (x = -1, timeout = 50; timeout && x < 0; timeout--) {
 142                 usleep_range(1000, 1100);
 143                 x = dcon_read(dcon, DCON_REG_ID);
 144         }
 145         if (x < 0) {
 146                 pr_err("unable to stabilize dcon's smbus, reasserting power and praying.\n");
 147                 BUG_ON(olpc_board_at_least(olpc_board(0xc2)));
 148                 pm = 0;
 149                 olpc_ec_cmd(EC_DCON_POWER_MODE, &pm, 1, NULL, 0);
 150                 msleep(100);
 151                 is_powered_down = 1;
 152                 goto power_up;  /* argh, stupid hardware.. */
 153         }
 154
 155         if (is_powered_down)
 156                 return dcon_hw_init(dcon, 0);
 157         return 0;
 158 }
 159
 160 static void dcon_set_backlight(struct dcon_priv *dcon, u8 level)
 161 {
 162         dcon->bl_val = level;
 163         dcon_write(dcon, DCON_REG_BRIGHT, dcon->bl_val);
 164
 165         /* Purposely turn off the backlight when we go to level 0 */
 166         if (dcon->bl_val == 0) {
 167                 dcon->disp_mode &= ~MODE_BL_ENABLE;
 168                 dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
 169         } else if (!(dcon->disp_mode & MODE_BL_ENABLE)) {
 170                 dcon->disp_mode |= MODE_BL_ENABLE;
 171                 dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
 172         }
 173 }
 174
 175 /* Set the output type to either color or mono */
 176 static int dcon_set_mono_mode(struct dcon_priv *dcon, bool enable_mono)
 177 {
 178         if (dcon->mono == enable_mono)
 179                 return 0;
 180
 181         dcon->mono = enable_mono;
 182
 183         if (enable_mono) {
 184                 dcon->disp_mode &= ~(MODE_CSWIZZLE | MODE_COL_AA);
 185                 dcon->disp_mode |= MODE_MONO_LUMA;
 186         } else {
 187                 dcon->disp_mode &= ~(MODE_MONO_LUMA);
 188                 dcon->disp_mode |= MODE_CSWIZZLE | MODE_COL_AA;
 189         }
 190
 191         dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
 192         return 0;
 193 }
 194
 195 /* For now, this will be really stupid - we need to address how
 196  * DCONLOAD works in a sleep and account for it accordingly
 197  */
 198
 199 static void dcon_sleep(struct dcon_priv *dcon, bool sleep)
 200 {
 201         int x;
 202
 203         /* Turn off the backlight and put the DCON to sleep */
 204
 205         if (dcon->asleep == sleep)
 206                 return;
 207
 208         if (!olpc_board_at_least(olpc_board(0xc2)))
 209                 return;
 210
 211         if (sleep) {
 212                 u8 pm = 0;
 213                 x = olpc_ec_cmd(EC_DCON_POWER_MODE, &pm, 1, NULL, 0);
 214                 if (x)
 215                         pr_warn("unable to force dcon to power down: %d!\n", x);
 216                 else
 217                         dcon->asleep = sleep;
 218         } else {
 219                 /* Only re-enable the backlight if the backlight value is set */
 220                 if (dcon->bl_val != 0)
 221                         dcon->disp_mode |= MODE_BL_ENABLE;
 222                 x = dcon_bus_stabilize(dcon, 1);
 223                 if (x)
 224                         pr_warn("unable to reinit dcon hardware: %d!\n", x);
 225                 else
 226                         dcon->asleep = sleep;
 227
 228                 /* Restore backlight */
 229                 dcon_set_backlight(dcon, dcon->bl_val);
 230         }
 231
 232         /* We should turn off some stuff in the framebuffer - but what? */
 233 }
 234
 235 /* the DCON seems to get confused if we change DCONLOAD too
 236  * frequently -- i.e., approximately faster than frame time.
 237  * normally we don't change it this fast, so in general we won't
 238  * delay here.
 239  */
 240 static void dcon_load_holdoff(struct dcon_priv *dcon)
 241 {
 242         struct timespec delta_t, now;
 243         while (1) {
 244                 getnstimeofday(&now);
 245                 delta_t = timespec_sub(now, dcon->load_time);
 246                 if (delta_t.tv_sec != 0 ||
 247                         delta_t.tv_nsec > NSEC_PER_MSEC * 20) {
 248                         break;
 249                 }
 250                 mdelay(4);
 251         }
 252 }
 253
 254 static bool dcon_blank_fb(struct dcon_priv *dcon, bool blank)
 255 {
 256         int err;
 257
 258         if (!lock_fb_info(dcon->fbinfo)) {
 259                 dev_err(&dcon->client->dev, "unable to lock framebuffer\n");
 260                 return false;
 261         }
 262         console_lock();
 263         dcon->ignore_fb_events = true;
 264         err = fb_blank(dcon->fbinfo,
 265                         blank ? FB_BLANK_POWERDOWN : FB_BLANK_UNBLANK);
 266         dcon->ignore_fb_events = false;
 267         console_unlock();
 268         unlock_fb_info(dcon->fbinfo);
 269
 270         if (err) {
 271                 dev_err(&dcon->client->dev, "couldn't %sblank framebuffer\n",
 272                                 blank ? "" : "un");
 273                 return false;
 274         }
 275         return true;
 276 }
 277
 278 /* Set the source of the display (CPU or DCON) */
 279 static void dcon_source_switch(struct work_struct *work)
 280 {
 281         struct dcon_priv *dcon = container_of(work, struct dcon_priv,
 282                         switch_source);
 283         int source = dcon->pending_src;
 284
 285         if (dcon->curr_src == source)
 286                 return;
 287
 288         dcon_load_holdoff(dcon);
 289
 290         dcon->switched = false;
 291
 292         switch (source) {
 293         case DCON_SOURCE_CPU:
 294                 pr_info("dcon_source_switch to CPU\n");
 295                 /* Enable the scanline interrupt bit */
 296                 if (dcon_write(dcon, DCON_REG_MODE,
 297                                 dcon->disp_mode | MODE_SCAN_INT))
 298                         pr_err("couldn't enable scanline interrupt!\n");
 299                 else
 300                         /* Wait up to one second for the scanline interrupt */
 301                         wait_event_timeout(dcon->waitq, dcon->switched, HZ);
 302
 303                 if (!dcon->switched)
 304                         pr_err("Timeout entering CPU mode; expect a screen glitch.\n");
 305
 306                 /* Turn off the scanline interrupt */
 307                 if (dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode))
 308                         pr_err("couldn't disable scanline interrupt!\n");
 309
 310                 /*
 311                  * Ideally we'd like to disable interrupts here so that the
 312                  * fb unblanking and DCON turn on happen at a known time value;
 313                  * however, we can't do that right now with fb_blank
 314                  * messing with semaphores.
 315                  *
 316                  * For now, we just hope..
 317                  */
 318                 if (!dcon_blank_fb(dcon, false)) {
 319                         pr_err("Failed to enter CPU mode\n");
 320                         dcon->pending_src = DCON_SOURCE_DCON;
 321                         return;
 322                 }
 323
 324                 /* And turn off the DCON */
 325                 pdata->set_dconload(1);
 326                 getnstimeofday(&dcon->load_time);
 327
 328                 pr_info("The CPU has control\n");
 329                 break;
 330         case DCON_SOURCE_DCON:
 331         {
 332                 struct timespec delta_t;
 333
 334                 pr_info("dcon_source_switch to DCON\n");
 335
 336                 /* Clear DCONLOAD - this implies that the DCON is in control */
 337                 pdata->set_dconload(0);
 338                 getnstimeofday(&dcon->load_time);
 339
 340                 wait_event_timeout(dcon->waitq, dcon->switched, HZ/2);
 341
 342                 if (!dcon->switched) {
 343                         pr_err("Timeout entering DCON mode; expect a screen glitch.\n");
 344                 } else {
 345                         /* sometimes the DCON doesn't follow its own rules,
 346                          * and doesn't wait for two vsync pulses before
 347                          * ack'ing the frame load with an IRQ.  the result
 348                          * is that the display shows the *previously*
 349                          * loaded frame.  we can detect this by looking at
 350                          * the time between asserting DCONLOAD and the IRQ --
 351                          * if it's less than 20msec, then the DCON couldn't
 352                          * have seen two VSYNC pulses.  in that case we
 353                          * deassert and reassert, and hope for the best.
 354                          * see http://dev.laptop.org/ticket/9664
 355                          */
 356                         delta_t = timespec_sub(dcon->irq_time, dcon->load_time);
 357                         if (dcon->switched && delta_t.tv_sec == 0 &&
 358                                         delta_t.tv_nsec < NSEC_PER_MSEC * 20) {
 359                                 pr_err("missed loading, retrying\n");
 360                                 pdata->set_dconload(1);
 361                                 mdelay(41);
 362                                 pdata->set_dconload(0);
 363                                 getnstimeofday(&dcon->load_time);
 364                                 mdelay(41);
 365                         }
 366                 }
 367
 368                 dcon_blank_fb(dcon, true);
 369                 pr_info("The DCON has control\n");
 370                 break;
 371         }
 372         default:
 373                 BUG();
 374         }
 375
 376         dcon->curr_src = source;
 377 }
 378
 379 static void dcon_set_source(struct dcon_priv *dcon, int arg)
 380 {
 381         if (dcon->pending_src == arg)
 382                 return;
 383
 384         dcon->pending_src = arg;
 385
 386         if (dcon->curr_src != arg)
 387                 schedule_work(&dcon->switch_source);
 388 }
 389
 390 static void dcon_set_source_sync(struct dcon_priv *dcon, int arg)
 391 {
 392         dcon_set_source(dcon, arg);
 393         flush_scheduled_work();
 394 }
 395
 396 static ssize_t dcon_mode_show(struct device *dev,
 397         struct device_attribute *attr, char *buf)
 398 {
 399         struct dcon_priv *dcon = dev_get_drvdata(dev);
 400         return sprintf(buf, "%4.4X\n", dcon->disp_mode);
 401 }
 402
 403 static ssize_t dcon_sleep_show(struct device *dev,
 404         struct device_attribute *attr, char *buf)
 405 {
 406
 407         struct dcon_priv *dcon = dev_get_drvdata(dev);
 408         return sprintf(buf, "%d\n", dcon->asleep);
 409 }
 410
 411 static ssize_t dcon_freeze_show(struct device *dev,
 412         struct device_attribute *attr, char *buf)
 413 {
 414         struct dcon_priv *dcon = dev_get_drvdata(dev);
 415         return sprintf(buf, "%d\n", dcon->curr_src == DCON_SOURCE_DCON ? 1 : 0);
 416 }
 417
 418 static ssize_t dcon_mono_show(struct device *dev,
 419         struct device_attribute *attr, char *buf)
 420 {
 421         struct dcon_priv *dcon = dev_get_drvdata(dev);
 422         return sprintf(buf, "%d\n", dcon->mono);
 423 }
 424
 425 static ssize_t dcon_resumeline_show(struct device *dev,
 426         struct device_attribute *attr, char *buf)
 427 {
 428         return sprintf(buf, "%d\n", resumeline);
 429 }
 430
 431 static ssize_t dcon_mono_store(struct device *dev,
 432         struct device_attribute *attr, const char *buf, size_t count)
 433 {
 434         unsigned long enable_mono;
 435         int rc;
 436
 437         rc = kstrtoul(buf, 10, &enable_mono);
 438         if (rc)
 439                 return rc;
 440
 441         dcon_set_mono_mode(dev_get_drvdata(dev), enable_mono ? true : false);
 442
 443         return count;
 444 }
 445
 446 static ssize_t dcon_freeze_store(struct device *dev,
 447         struct device_attribute *attr, const char *buf, size_t count)
 448 {
 449         struct dcon_priv *dcon = dev_get_drvdata(dev);
 450         unsigned long output;
 451         int ret;
 452
 453         ret = kstrtoul(buf, 10, &output);
 454         if (ret)
 455                 return ret;
 456
 457         pr_info("dcon_freeze_store: %lu\n", output);
 458
 459         switch (output) {
 460         case 0:
 461                 dcon_set_source(dcon, DCON_SOURCE_CPU);
 462                 break;
 463         case 1:
 464                 dcon_set_source_sync(dcon, DCON_SOURCE_DCON);
 465                 break;
 466         case 2:  /* normally unused */
 467                 dcon_set_source(dcon, DCON_SOURCE_DCON);
 468                 break;
 469         default:
 470                 return -EINVAL;
 471         }
 472
 473         return count;
 474 }
 475
 476 static ssize_t dcon_resumeline_store(struct device *dev,
 477         struct device_attribute *attr, const char *buf, size_t count)
 478 {
 479         unsigned short rl;
 480         int rc;
 481
 482         rc = kstrtou16(buf, 10, &rl);
 483         if (rc)
 484                 return rc;
 485
 486         resumeline = rl;
 487         dcon_write(dev_get_drvdata(dev), DCON_REG_SCAN_INT, resumeline);
 488
 489         return count;
 490 }
 491
 492 static ssize_t dcon_sleep_store(struct device *dev,
 493         struct device_attribute *attr, const char *buf, size_t count)
 494 {
 495         unsigned long output;
 496         int ret;
 497
 498         ret = kstrtoul(buf, 10, &output);
 499         if (ret)
 500                 return ret;
 501
 502         dcon_sleep(dev_get_drvdata(dev), output ? true : false);
 503         return count;
 504 }
 505
 506 static struct device_attribute dcon_device_files[] = {
 507         __ATTR(mode, 0444, dcon_mode_show, NULL),
 508         __ATTR(sleep, 0644, dcon_sleep_show, dcon_sleep_store),
 509         __ATTR(freeze, 0644, dcon_freeze_show, dcon_freeze_store),
 510         __ATTR(monochrome, 0644, dcon_mono_show, dcon_mono_store),
 511         __ATTR(resumeline, 0644, dcon_resumeline_show, dcon_resumeline_store),
 512 };
 513
 514 static int dcon_bl_update(struct backlight_device *dev)
 515 {
 516         struct dcon_priv *dcon = bl_get_data(dev);
 517         u8 level = dev->props.brightness & 0x0F;
 518
 519         if (dev->props.power != FB_BLANK_UNBLANK)
 520                 level = 0;
 521
 522         if (level != dcon->bl_val)
 523                 dcon_set_backlight(dcon, level);
 524
 525         /* power down the DCON when the screen is blanked */
 526         if (!dcon->ignore_fb_events)
 527                 dcon_sleep(dcon, !!(dev->props.state & BL_CORE_FBBLANK));
 528
 529         return 0;
 530 }
 531
 532 static int dcon_bl_get(struct backlight_device *dev)
 533 {
 534         struct dcon_priv *dcon = bl_get_data(dev);
 535         return dcon->bl_val;
 536 }
 537
 538 static const struct backlight_ops dcon_bl_ops = {
 539         .update_status = dcon_bl_update,
 540         .get_brightness = dcon_bl_get,
 541 };
 542
 543 static struct backlight_properties dcon_bl_props = {
 544         .max_brightness = 15,
 545         .type = BACKLIGHT_RAW,
 546         .power = FB_BLANK_UNBLANK,
 547 };
 548
 549 static int dcon_reboot_notify(struct notifier_block *nb,
 550                               unsigned long foo, void *bar)
 551 {
 552         struct dcon_priv *dcon = container_of(nb, struct dcon_priv, reboot_nb);
 553
 554         if (!dcon || !dcon->client)
 555                 return NOTIFY_DONE;
 556
 557         /* Turn off the DCON. Entirely. */
 558         dcon_write(dcon, DCON_REG_MODE, 0x39);
 559         dcon_write(dcon, DCON_REG_MODE, 0x32);
 560         return NOTIFY_DONE;
 561 }
 562
 563 static int unfreeze_on_panic(struct notifier_block *nb,
 564                              unsigned long e, void *p)
 565 {
 566         pdata->set_dconload(1);
 567         return NOTIFY_DONE;
 568 }
 569
 570 static struct notifier_block dcon_panic_nb = {
 571         .notifier_call = unfreeze_on_panic,
 572 };
 573
 574 static int dcon_detect(struct i2c_client *client, struct i2c_board_info *info)
 575 {
 576         strlcpy(info->type, "olpc_dcon", I2C_NAME_SIZE);
 577
 578         return 0;
 579 }
 580
 581 static int dcon_probe(struct i2c_client *client, const struct i2c_device_id *id)
 582 {
 583         struct dcon_priv *dcon;
 584         int rc, i, j;
 585
 586         if (!pdata)
 587                 return -ENXIO;
 588
 589         dcon = kzalloc(sizeof(*dcon), GFP_KERNEL);
 590         if (!dcon)
 591                 return -ENOMEM;
 592
 593         dcon->client = client;
 594         init_waitqueue_head(&dcon->waitq);
 595         INIT_WORK(&dcon->switch_source, dcon_source_switch);
 596         dcon->reboot_nb.notifier_call = dcon_reboot_notify;
 597         dcon->reboot_nb.priority = -1;
 598
 599         i2c_set_clientdata(client, dcon);
 600
 601         if (num_registered_fb < 1) {
 602                 dev_err(&client->dev, "DCON driver requires a registered fb\n");
 603                 rc = -EIO;
 604                 goto einit;
 605         }
 606         dcon->fbinfo = registered_fb[0];
 607
 608         rc = dcon_hw_init(dcon, 1);
 609         if (rc)
 610                 goto einit;
 611
 612         /* Add the DCON device */
 613
 614         dcon_device = platform_device_alloc("dcon", -1);
 615
 616         if (dcon_device == NULL) {
 617                 pr_err("Unable to create the DCON device\n");
 618                 rc = -ENOMEM;
 619                 goto eirq;
 620         }
 621         rc = platform_device_add(dcon_device);
 622         platform_set_drvdata(dcon_device, dcon);
 623
 624         if (rc) {
 625                 pr_err("Unable to add the DCON device\n");
 626                 goto edev;
 627         }
 628
 629         for (i = 0; i < ARRAY_SIZE(dcon_device_files); i++) {
 630                 rc = device_create_file(&dcon_device->dev,
 631                                         &dcon_device_files[i]);
 632                 if (rc) {
 633                         dev_err(&dcon_device->dev, "Cannot create sysfs file\n");
 634                         goto ecreate;
 635                 }
 636         }
 637
 638         dcon->bl_val = dcon_read(dcon, DCON_REG_BRIGHT) & 0x0F;
 639
 640         /* Add the backlight device for the DCON */
 641         dcon_bl_props.brightness = dcon->bl_val;
 642         dcon->bl_dev = backlight_device_register("dcon-bl", &dcon_device->dev,
 643                 dcon, &dcon_bl_ops, &dcon_bl_props);
 644         if (IS_ERR(dcon->bl_dev)) {
 645                 dev_err(&client->dev, "cannot register backlight dev (%ld)\n",
 646                                 PTR_ERR(dcon->bl_dev));
 647                 dcon->bl_dev = NULL;
 648         }
 649
 650         register_reboot_notifier(&dcon->reboot_nb);
 651         atomic_notifier_chain_register(&panic_notifier_list, &dcon_panic_nb);
 652
 653         return 0;
 654
 655  ecreate:
 656         for (j = 0; j < i; j++)
 657                 device_remove_file(&dcon_device->dev, &dcon_device_files[j]);
 658  edev:
 659         platform_device_unregister(dcon_device);
 660         dcon_device = NULL;
 661  eirq:
 662         free_irq(DCON_IRQ, dcon);
 663  einit:
 664         kfree(dcon);
 665         return rc;
 666 }
 667
 668 static int dcon_remove(struct i2c_client *client)
 669 {
 670         struct dcon_priv *dcon = i2c_get_clientdata(client);
 671
 672         unregister_reboot_notifier(&dcon->reboot_nb);
 673         atomic_notifier_chain_unregister(&panic_notifier_list, &dcon_panic_nb);
 674
 675         free_irq(DCON_IRQ, dcon);
 676
 677         if (dcon->bl_dev)
 678                 backlight_device_unregister(dcon->bl_dev);
 679
 680         if (dcon_device != NULL)
 681                 platform_device_unregister(dcon_device);
 682         cancel_work_sync(&dcon->switch_source);
 683
 684         kfree(dcon);
 685
 686         return 0;
 687 }
 688
 689 #ifdef CONFIG_PM
 690 static int dcon_suspend(struct device *dev)
 691 {
 692         struct i2c_client *client = to_i2c_client(dev);
 693         struct dcon_priv *dcon = i2c_get_clientdata(client);
 694
 695         if (!dcon->asleep) {
 696                 /* Set up the DCON to have the source */
 697                 dcon_set_source_sync(dcon, DCON_SOURCE_DCON);
 698         }
 699
 700         return 0;
 701 }
 702
 703 static int dcon_resume(struct device *dev)
 704 {
 705         struct i2c_client *client = to_i2c_client(dev);
 706         struct dcon_priv *dcon = i2c_get_clientdata(client);
 707
 708         if (!dcon->asleep) {
 709                 dcon_bus_stabilize(dcon, 0);
 710                 dcon_set_source(dcon, DCON_SOURCE_CPU);
 711         }
 712
 713         return 0;
 714 }
 715
 716 #else
 717
 718 #define dcon_suspend NULL
 719 #define dcon_resume NULL
 720
 721 #endif /* CONFIG_PM */
 722
 723
 724 irqreturn_t dcon_interrupt(int irq, void *id)
 725 {
 726         struct dcon_priv *dcon = id;
 727         u8 status;
 728
 729         if (pdata->read_status(&status))
 730                 return IRQ_NONE;
 731
 732         switch (status & 3) {
 733         case 3:
 734                 pr_debug("DCONLOAD_MISSED interrupt\n");
 735                 break;
 736
 737         case 2: /* switch to DCON mode */
 738         case 1: /* switch to CPU mode */
 739                 dcon->switched = true;
 740                 getnstimeofday(&dcon->irq_time);
 741                 wake_up(&dcon->waitq);
 742                 break;
 743
 744         case 0:
 745                 /* workaround resume case:  the DCON (on 1.5) doesn't
 746                  * ever assert status 0x01 when switching to CPU mode
 747                  * during resume.  this is because DCONLOAD is de-asserted
 748                  * _immediately_ upon exiting S3, so the actual release
 749                  * of the DCON happened long before this point.
 750                  * see http://dev.laptop.org/ticket/9869
 751                  */
 752                 if (dcon->curr_src != dcon->pending_src && !dcon->switched) {
 753                         dcon->switched = true;
 754                         getnstimeofday(&dcon->irq_time);
 755                         wake_up(&dcon->waitq);
 756                         pr_debug("switching w/ status 0/0\n");
 757                 } else {
 758                         pr_debug("scanline interrupt w/CPU\n");
 759                 }
 760         }
 761
 762         return IRQ_HANDLED;
 763 }
 764
 765 static const struct dev_pm_ops dcon_pm_ops = {
 766         .suspend = dcon_suspend,
 767         .resume = dcon_resume,
 768 };
 769
 770 static const struct i2c_device_id dcon_idtable[] = {
 771         { "olpc_dcon",  0 },
 772         { }
 773 };
 774 MODULE_DEVICE_TABLE(i2c, dcon_idtable);
 775
 776 struct i2c_driver dcon_driver = {
 777         .driver = {
 778                 .name   = "olpc_dcon",
 779                 .pm = &dcon_pm_ops,
 780         },
 781         .class = I2C_CLASS_DDC | I2C_CLASS_HWMON,
 782         .id_table = dcon_idtable,
 783         .probe = dcon_probe,
 784         .remove = dcon_remove,
 785         .detect = dcon_detect,
 786         .address_list = normal_i2c,
 787 };
 788
 789 static int __init olpc_dcon_init(void)
 790 {
 791 #ifdef CONFIG_FB_OLPC_DCON_1_5
 792         /* XO-1.5 */
 793         if (olpc_board_at_least(olpc_board(0xd0)))
 794                 pdata = &dcon_pdata_xo_1_5;
 795 #endif
 796 #ifdef CONFIG_FB_OLPC_DCON_1
 797         if (!pdata)
 798                 pdata = &dcon_pdata_xo_1;
 799 #endif
 800
 801         return i2c_add_driver(&dcon_driver);
 802 }
 803
 804 static void __exit olpc_dcon_exit(void)
 805 {
 806         i2c_del_driver(&dcon_driver);
 807 }
 808
 809 module_init(olpc_dcon_init);
 810 module_exit(olpc_dcon_exit);
 811
 812 MODULE_LICENSE("GPL");