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         console_lock();
 259         if (!lock_fb_info(dcon->fbinfo)) {
 260                 console_unlock();
 261                 dev_err(&dcon->client->dev, "unable to lock framebuffer\n");
 262                 return false;
 263         }
 264
 265         dcon->ignore_fb_events = true;
 266         err = fb_blank(dcon->fbinfo,
 267                         blank ? FB_BLANK_POWERDOWN : FB_BLANK_UNBLANK);
 268         dcon->ignore_fb_events = false;
 269         unlock_fb_info(dcon->fbinfo);
 270         console_unlock();
 271
 272         if (err) {
 273                 dev_err(&dcon->client->dev, "couldn't %sblank framebuffer\n",
 274                                 blank ? "" : "un");
 275                 return false;
 276         }
 277         return true;
 278 }
 279
 280 /* Set the source of the display (CPU or DCON) */
 281 static void dcon_source_switch(struct work_struct *work)
 282 {
 283         struct dcon_priv *dcon = container_of(work, struct dcon_priv,
 284                         switch_source);
 285         int source = dcon->pending_src;
 286
 287         if (dcon->curr_src == source)
 288                 return;
 289
 290         dcon_load_holdoff(dcon);
 291
 292         dcon->switched = false;
 293
 294         switch (source) {
 295         case DCON_SOURCE_CPU:
 296                 pr_info("dcon_source_switch to CPU\n");
 297                 /* Enable the scanline interrupt bit */
 298                 if (dcon_write(dcon, DCON_REG_MODE,
 299                                 dcon->disp_mode | MODE_SCAN_INT))
 300                         pr_err("couldn't enable scanline interrupt!\n");
 301                 else
 302                         /* Wait up to one second for the scanline interrupt */
 303                         wait_event_timeout(dcon->waitq, dcon->switched, HZ);
 304
 305                 if (!dcon->switched)
 306                         pr_err("Timeout entering CPU mode; expect a screen glitch.\n");
 307
 308                 /* Turn off the scanline interrupt */
 309                 if (dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode))
 310                         pr_err("couldn't disable scanline interrupt!\n");
 311
 312                 /*
 313                  * Ideally we'd like to disable interrupts here so that the
 314                  * fb unblanking and DCON turn on happen at a known time value;
 315                  * however, we can't do that right now with fb_blank
 316                  * messing with semaphores.
 317                  *
 318                  * For now, we just hope..
 319                  */
 320                 if (!dcon_blank_fb(dcon, false)) {
 321                         pr_err("Failed to enter CPU mode\n");
 322                         dcon->pending_src = DCON_SOURCE_DCON;
 323                         return;
 324                 }
 325
 326                 /* And turn off the DCON */
 327                 pdata->set_dconload(1);
 328                 getnstimeofday(&dcon->load_time);
 329
 330                 pr_info("The CPU has control\n");
 331                 break;
 332         case DCON_SOURCE_DCON:
 333         {
 334                 struct timespec delta_t;
 335
 336                 pr_info("dcon_source_switch to DCON\n");
 337
 338                 /* Clear DCONLOAD - this implies that the DCON is in control */
 339                 pdata->set_dconload(0);
 340                 getnstimeofday(&dcon->load_time);
 341
 342                 wait_event_timeout(dcon->waitq, dcon->switched, HZ/2);
 343
 344                 if (!dcon->switched) {
 345                         pr_err("Timeout entering DCON mode; expect a screen glitch.\n");
 346                 } else {
 347                         /* sometimes the DCON doesn't follow its own rules,
 348                          * and doesn't wait for two vsync pulses before
 349                          * ack'ing the frame load with an IRQ.  the result
 350                          * is that the display shows the *previously*
 351                          * loaded frame.  we can detect this by looking at
 352                          * the time between asserting DCONLOAD and the IRQ --
 353                          * if it's less than 20msec, then the DCON couldn't
 354                          * have seen two VSYNC pulses.  in that case we
 355                          * deassert and reassert, and hope for the best.
 356                          * see http://dev.laptop.org/ticket/9664
 357                          */
 358                         delta_t = timespec_sub(dcon->irq_time, dcon->load_time);
 359                         if (dcon->switched && delta_t.tv_sec == 0 &&
 360                                         delta_t.tv_nsec < NSEC_PER_MSEC * 20) {
 361                                 pr_err("missed loading, retrying\n");
 362                                 pdata->set_dconload(1);
 363                                 mdelay(41);
 364                                 pdata->set_dconload(0);
 365                                 getnstimeofday(&dcon->load_time);
 366                                 mdelay(41);
 367                         }
 368                 }
 369
 370                 dcon_blank_fb(dcon, true);
 371                 pr_info("The DCON has control\n");
 372                 break;
 373         }
 374         default:
 375                 BUG();
 376         }
 377
 378         dcon->curr_src = source;
 379 }
 380
 381 static void dcon_set_source(struct dcon_priv *dcon, int arg)
 382 {
 383         if (dcon->pending_src == arg)
 384                 return;
 385
 386         dcon->pending_src = arg;
 387
 388         if (dcon->curr_src != arg)
 389                 schedule_work(&dcon->switch_source);
 390 }
 391
 392 static void dcon_set_source_sync(struct dcon_priv *dcon, int arg)
 393 {
 394         dcon_set_source(dcon, arg);
 395         flush_scheduled_work();
 396 }
 397
 398 static ssize_t dcon_mode_show(struct device *dev,
 399         struct device_attribute *attr, char *buf)
 400 {
 401         struct dcon_priv *dcon = dev_get_drvdata(dev);
 402         return sprintf(buf, "%4.4X\n", dcon->disp_mode);
 403 }
 404
 405 static ssize_t dcon_sleep_show(struct device *dev,
 406         struct device_attribute *attr, char *buf)
 407 {
 408
 409         struct dcon_priv *dcon = dev_get_drvdata(dev);
 410         return sprintf(buf, "%d\n", dcon->asleep);
 411 }
 412
 413 static ssize_t dcon_freeze_show(struct device *dev,
 414         struct device_attribute *attr, char *buf)
 415 {
 416         struct dcon_priv *dcon = dev_get_drvdata(dev);
 417         return sprintf(buf, "%d\n", dcon->curr_src == DCON_SOURCE_DCON ? 1 : 0);
 418 }
 419
 420 static ssize_t dcon_mono_show(struct device *dev,
 421         struct device_attribute *attr, char *buf)
 422 {
 423         struct dcon_priv *dcon = dev_get_drvdata(dev);
 424         return sprintf(buf, "%d\n", dcon->mono);
 425 }
 426
 427 static ssize_t dcon_resumeline_show(struct device *dev,
 428         struct device_attribute *attr, char *buf)
 429 {
 430         return sprintf(buf, "%d\n", resumeline);
 431 }
 432
 433 static ssize_t dcon_mono_store(struct device *dev,
 434         struct device_attribute *attr, const char *buf, size_t count)
 435 {
 436         unsigned long enable_mono;
 437         int rc;
 438
 439         rc = kstrtoul(buf, 10, &enable_mono);
 440         if (rc)
 441                 return rc;
 442
 443         dcon_set_mono_mode(dev_get_drvdata(dev), enable_mono ? true : false);
 444
 445         return count;
 446 }
 447
 448 static ssize_t dcon_freeze_store(struct device *dev,
 449         struct device_attribute *attr, const char *buf, size_t count)
 450 {
 451         struct dcon_priv *dcon = dev_get_drvdata(dev);
 452         unsigned long output;
 453         int ret;
 454
 455         ret = kstrtoul(buf, 10, &output);
 456         if (ret)
 457                 return ret;
 458
 459         pr_info("dcon_freeze_store: %lu\n", output);
 460
 461         switch (output) {
 462         case 0:
 463                 dcon_set_source(dcon, DCON_SOURCE_CPU);
 464                 break;
 465         case 1:
 466                 dcon_set_source_sync(dcon, DCON_SOURCE_DCON);
 467                 break;
 468         case 2:  /* normally unused */
 469                 dcon_set_source(dcon, DCON_SOURCE_DCON);
 470                 break;
 471         default:
 472                 return -EINVAL;
 473         }
 474
 475         return count;
 476 }
 477
 478 static ssize_t dcon_resumeline_store(struct device *dev,
 479         struct device_attribute *attr, const char *buf, size_t count)
 480 {
 481         unsigned short rl;
 482         int rc;
 483
 484         rc = kstrtou16(buf, 10, &rl);
 485         if (rc)
 486                 return rc;
 487
 488         resumeline = rl;
 489         dcon_write(dev_get_drvdata(dev), DCON_REG_SCAN_INT, resumeline);
 490
 491         return count;
 492 }
 493
 494 static ssize_t dcon_sleep_store(struct device *dev,
 495         struct device_attribute *attr, const char *buf, size_t count)
 496 {
 497         unsigned long output;
 498         int ret;
 499
 500         ret = kstrtoul(buf, 10, &output);
 501         if (ret)
 502                 return ret;
 503
 504         dcon_sleep(dev_get_drvdata(dev), output ? true : false);
 505         return count;
 506 }
 507
 508 static struct device_attribute dcon_device_files[] = {
 509         __ATTR(mode, 0444, dcon_mode_show, NULL),
 510         __ATTR(sleep, 0644, dcon_sleep_show, dcon_sleep_store),
 511         __ATTR(freeze, 0644, dcon_freeze_show, dcon_freeze_store),
 512         __ATTR(monochrome, 0644, dcon_mono_show, dcon_mono_store),
 513         __ATTR(resumeline, 0644, dcon_resumeline_show, dcon_resumeline_store),
 514 };
 515
 516 static int dcon_bl_update(struct backlight_device *dev)
 517 {
 518         struct dcon_priv *dcon = bl_get_data(dev);
 519         u8 level = dev->props.brightness & 0x0F;
 520
 521         if (dev->props.power != FB_BLANK_UNBLANK)
 522                 level = 0;
 523
 524         if (level != dcon->bl_val)
 525                 dcon_set_backlight(dcon, level);
 526
 527         /* power down the DCON when the screen is blanked */
 528         if (!dcon->ignore_fb_events)
 529                 dcon_sleep(dcon, !!(dev->props.state & BL_CORE_FBBLANK));
 530
 531         return 0;
 532 }
 533
 534 static int dcon_bl_get(struct backlight_device *dev)
 535 {
 536         struct dcon_priv *dcon = bl_get_data(dev);
 537         return dcon->bl_val;
 538 }
 539
 540 static const struct backlight_ops dcon_bl_ops = {
 541         .update_status = dcon_bl_update,
 542         .get_brightness = dcon_bl_get,
 543 };
 544
 545 static struct backlight_properties dcon_bl_props = {
 546         .max_brightness = 15,
 547         .type = BACKLIGHT_RAW,
 548         .power = FB_BLANK_UNBLANK,
 549 };
 550
 551 static int dcon_reboot_notify(struct notifier_block *nb,
 552                               unsigned long foo, void *bar)
 553 {
 554         struct dcon_priv *dcon = container_of(nb, struct dcon_priv, reboot_nb);
 555
 556         if (!dcon || !dcon->client)
 557                 return NOTIFY_DONE;
 558
 559         /* Turn off the DCON. Entirely. */
 560         dcon_write(dcon, DCON_REG_MODE, 0x39);
 561         dcon_write(dcon, DCON_REG_MODE, 0x32);
 562         return NOTIFY_DONE;
 563 }
 564
 565 static int unfreeze_on_panic(struct notifier_block *nb,
 566                              unsigned long e, void *p)
 567 {
 568         pdata->set_dconload(1);
 569         return NOTIFY_DONE;
 570 }
 571
 572 static struct notifier_block dcon_panic_nb = {
 573         .notifier_call = unfreeze_on_panic,
 574 };
 575
 576 static int dcon_detect(struct i2c_client *client, struct i2c_board_info *info)
 577 {
 578         strlcpy(info->type, "olpc_dcon", I2C_NAME_SIZE);
 579
 580         return 0;
 581 }
 582
 583 static int dcon_probe(struct i2c_client *client, const struct i2c_device_id *id)
 584 {
 585         struct dcon_priv *dcon;
 586         int rc, i, j;
 587
 588         if (!pdata)
 589                 return -ENXIO;
 590
 591         dcon = kzalloc(sizeof(*dcon), GFP_KERNEL);
 592         if (!dcon)
 593                 return -ENOMEM;
 594
 595         dcon->client = client;
 596         init_waitqueue_head(&dcon->waitq);
 597         INIT_WORK(&dcon->switch_source, dcon_source_switch);
 598         dcon->reboot_nb.notifier_call = dcon_reboot_notify;
 599         dcon->reboot_nb.priority = -1;
 600
 601         i2c_set_clientdata(client, dcon);
 602
 603         if (num_registered_fb < 1) {
 604                 dev_err(&client->dev, "DCON driver requires a registered fb\n");
 605                 rc = -EIO;
 606                 goto einit;
 607         }
 608         dcon->fbinfo = registered_fb[0];
 609
 610         rc = dcon_hw_init(dcon, 1);
 611         if (rc)
 612                 goto einit;
 613
 614         /* Add the DCON device */
 615
 616         dcon_device = platform_device_alloc("dcon", -1);
 617
 618         if (dcon_device == NULL) {
 619                 pr_err("Unable to create the DCON device\n");
 620                 rc = -ENOMEM;
 621                 goto eirq;
 622         }
 623         rc = platform_device_add(dcon_device);
 624         platform_set_drvdata(dcon_device, dcon);
 625
 626         if (rc) {
 627                 pr_err("Unable to add the DCON device\n");
 628                 goto edev;
 629         }
 630
 631         for (i = 0; i < ARRAY_SIZE(dcon_device_files); i++) {
 632                 rc = device_create_file(&dcon_device->dev,
 633                                         &dcon_device_files[i]);
 634                 if (rc) {
 635                         dev_err(&dcon_device->dev, "Cannot create sysfs file\n");
 636                         goto ecreate;
 637                 }
 638         }
 639
 640         dcon->bl_val = dcon_read(dcon, DCON_REG_BRIGHT) & 0x0F;
 641
 642         /* Add the backlight device for the DCON */
 643         dcon_bl_props.brightness = dcon->bl_val;
 644         dcon->bl_dev = backlight_device_register("dcon-bl", &dcon_device->dev,
 645                 dcon, &dcon_bl_ops, &dcon_bl_props);
 646         if (IS_ERR(dcon->bl_dev)) {
 647                 dev_err(&client->dev, "cannot register backlight dev (%ld)\n",
 648                                 PTR_ERR(dcon->bl_dev));
 649                 dcon->bl_dev = NULL;
 650         }
 651
 652         register_reboot_notifier(&dcon->reboot_nb);
 653         atomic_notifier_chain_register(&panic_notifier_list, &dcon_panic_nb);
 654
 655         return 0;
 656
 657  ecreate:
 658         for (j = 0; j < i; j++)
 659                 device_remove_file(&dcon_device->dev, &dcon_device_files[j]);
 660  edev:
 661         platform_device_unregister(dcon_device);
 662         dcon_device = NULL;
 663  eirq:
 664         free_irq(DCON_IRQ, dcon);
 665  einit:
 666         kfree(dcon);
 667         return rc;
 668 }
 669
 670 static int dcon_remove(struct i2c_client *client)
 671 {
 672         struct dcon_priv *dcon = i2c_get_clientdata(client);
 673
 674         unregister_reboot_notifier(&dcon->reboot_nb);
 675         atomic_notifier_chain_unregister(&panic_notifier_list, &dcon_panic_nb);
 676
 677         free_irq(DCON_IRQ, dcon);
 678
 679         if (dcon->bl_dev)
 680                 backlight_device_unregister(dcon->bl_dev);
 681
 682         if (dcon_device != NULL)
 683                 platform_device_unregister(dcon_device);
 684         cancel_work_sync(&dcon->switch_source);
 685
 686         kfree(dcon);
 687
 688         return 0;
 689 }
 690
 691 #ifdef CONFIG_PM
 692 static int dcon_suspend(struct device *dev)
 693 {
 694         struct i2c_client *client = to_i2c_client(dev);
 695         struct dcon_priv *dcon = i2c_get_clientdata(client);
 696
 697         if (!dcon->asleep) {
 698                 /* Set up the DCON to have the source */
 699                 dcon_set_source_sync(dcon, DCON_SOURCE_DCON);
 700         }
 701
 702         return 0;
 703 }
 704
 705 static int dcon_resume(struct device *dev)
 706 {
 707         struct i2c_client *client = to_i2c_client(dev);
 708         struct dcon_priv *dcon = i2c_get_clientdata(client);
 709
 710         if (!dcon->asleep) {
 711                 dcon_bus_stabilize(dcon, 0);
 712                 dcon_set_source(dcon, DCON_SOURCE_CPU);
 713         }
 714
 715         return 0;
 716 }
 717
 718 #else
 719
 720 #define dcon_suspend NULL
 721 #define dcon_resume NULL
 722
 723 #endif /* CONFIG_PM */
 724
 725
 726 irqreturn_t dcon_interrupt(int irq, void *id)
 727 {
 728         struct dcon_priv *dcon = id;
 729         u8 status;
 730
 731         if (pdata->read_status(&status))
 732                 return IRQ_NONE;
 733
 734         switch (status & 3) {
 735         case 3:
 736                 pr_debug("DCONLOAD_MISSED interrupt\n");
 737                 break;
 738
 739         case 2: /* switch to DCON mode */
 740         case 1: /* switch to CPU mode */
 741                 dcon->switched = true;
 742                 getnstimeofday(&dcon->irq_time);
 743                 wake_up(&dcon->waitq);
 744                 break;
 745
 746         case 0:
 747                 /* workaround resume case:  the DCON (on 1.5) doesn't
 748                  * ever assert status 0x01 when switching to CPU mode
 749                  * during resume.  this is because DCONLOAD is de-asserted
 750                  * _immediately_ upon exiting S3, so the actual release
 751                  * of the DCON happened long before this point.
 752                  * see http://dev.laptop.org/ticket/9869
 753                  */
 754                 if (dcon->curr_src != dcon->pending_src && !dcon->switched) {
 755                         dcon->switched = true;
 756                         getnstimeofday(&dcon->irq_time);
 757                         wake_up(&dcon->waitq);
 758                         pr_debug("switching w/ status 0/0\n");
 759                 } else {
 760                         pr_debug("scanline interrupt w/CPU\n");
 761                 }
 762         }
 763
 764         return IRQ_HANDLED;
 765 }
 766
 767 static const struct dev_pm_ops dcon_pm_ops = {
 768         .suspend = dcon_suspend,
 769         .resume = dcon_resume,
 770 };
 771
 772 static const struct i2c_device_id dcon_idtable[] = {
 773         { "olpc_dcon",  0 },
 774         { }
 775 };
 776 MODULE_DEVICE_TABLE(i2c, dcon_idtable);
 777
 778 struct i2c_driver dcon_driver = {
 779         .driver = {
 780                 .name   = "olpc_dcon",
 781                 .pm = &dcon_pm_ops,
 782         },
 783         .class = I2C_CLASS_DDC | I2C_CLASS_HWMON,
 784         .id_table = dcon_idtable,
 785         .probe = dcon_probe,
 786         .remove = dcon_remove,
 787         .detect = dcon_detect,
 788         .address_list = normal_i2c,
 789 };
 790
 791 static int __init olpc_dcon_init(void)
 792 {
 793 #ifdef CONFIG_FB_OLPC_DCON_1_5
 794         /* XO-1.5 */
 795         if (olpc_board_at_least(olpc_board(0xd0)))
 796                 pdata = &dcon_pdata_xo_1_5;
 797 #endif
 798 #ifdef CONFIG_FB_OLPC_DCON_1
 799         if (!pdata)
 800                 pdata = &dcon_pdata_xo_1;
 801 #endif
 802
 803         return i2c_add_driver(&dcon_driver);
 804 }
 805
 806 static void __exit olpc_dcon_exit(void)
 807 {
 808         i2c_del_driver(&dcon_driver);
 809 }
 810
 811 module_init(olpc_dcon_init);
 812 module_exit(olpc_dcon_exit);
 813
 814 MODULE_LICENSE("GPL");