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
  15 #include <linux/kernel.h>
  16 #include <linux/fb.h>
  17 #include <linux/console.h>
  18 #include <linux/i2c.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/pci.h>
  21 #include <linux/pci_ids.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/delay.h>
  24 #include <linux/module.h>
  25 #include <linux/backlight.h>
  26 #include <linux/device.h>
  27 #include <linux/uaccess.h>
  28 #include <linux/ctype.h>
  29 #include <linux/reboot.h>
  30 #include <asm/tsc.h>
  31 #include <asm/olpc.h>
  32
  33 #include "olpc_dcon.h"
  34
  35 /* Module definitions */
  36
  37 static ushort resumeline = 898;
  38 module_param(resumeline, ushort, 0444);
  39
  40 /* Default off since it doesn't work on DCON ASIC in B-test OLPC board */
  41 static int useaa = 1;
  42 module_param(useaa, int, 0444);
  43
  44 static struct dcon_platform_data *pdata;
  45
  46 /* I2C structures */
  47
  48 /* Platform devices */
  49 static struct platform_device *dcon_device;
  50
  51 static DECLARE_WAIT_QUEUE_HEAD(dcon_wait_queue);
  52
  53 static unsigned short normal_i2c[] = { 0x0d, I2C_CLIENT_END };
  54
  55 static s32 dcon_write(struct dcon_priv *dcon, u8 reg, u16 val)
  56 {
  57         return i2c_smbus_write_word_data(dcon->client, reg, val);
  58 }
  59
  60 static s32 dcon_read(struct dcon_priv *dcon, u8 reg)
  61 {
  62         return i2c_smbus_read_word_data(dcon->client, reg);
  63 }
  64
  65 /* ===== API functions - these are called by a variety of users ==== */
  66
  67 static int dcon_hw_init(struct dcon_priv *dcon, int is_init)
  68 {
  69         uint16_t ver;
  70         int rc = 0;
  71
  72         ver = dcon_read(dcon, DCON_REG_ID);
  73         if ((ver >> 8) != 0xDC) {
  74                 printk(KERN_ERR "olpc-dcon:  DCON ID not 0xDCxx: 0x%04x instead.\n",
  75                         ver);
  76                 rc = -ENXIO;
  77                 goto err;
  78         }
  79
  80         if (is_init) {
  81                 printk(KERN_INFO "olpc-dcon:  Discovered DCON version %x\n",
  82                                 ver & 0xFF);
  83                 rc = pdata->init(dcon);
  84                 if (rc != 0) {
  85                         printk(KERN_ERR "olpc-dcon:  Unable to init.\n");
  86                         goto err;
  87                 }
  88         }
  89
  90         if (ver < 0xdc02) {
  91                 dev_err(&dcon->client->dev,
  92                                 "DCON v1 is unsupported, giving up..\n");
  93                 rc = -ENODEV;
  94                 goto err;
  95         }
  96
  97         /* SDRAM setup/hold time */
  98         dcon_write(dcon, 0x3a, 0xc040);
  99         dcon_write(dcon, 0x41, 0x0000);
 100         dcon_write(dcon, 0x41, 0x0101);
 101         dcon_write(dcon, 0x42, 0x0101);
 102
 103         /* Colour swizzle, AA, no passthrough, backlight */
 104         if (is_init) {
 105                 dcon->disp_mode = MODE_PASSTHRU | MODE_BL_ENABLE |
 106                                 MODE_CSWIZZLE;
 107                 if (useaa)
 108                         dcon->disp_mode |= MODE_COL_AA;
 109         }
 110         dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
 111
 112
 113         /* Set the scanline to interrupt on during resume */
 114         dcon_write(dcon, DCON_REG_SCAN_INT, resumeline);
 115
 116 err:
 117         return rc;
 118 }
 119
 120 /*
 121  * The smbus doesn't always come back due to what is believed to be
 122  * hardware (power rail) bugs.  For older models where this is known to
 123  * occur, our solution is to attempt to wait for the bus to stabilize;
 124  * if it doesn't happen, cut power to the dcon, repower it, and wait
 125  * for the bus to stabilize.  Rinse, repeat until we have a working
 126  * smbus.  For newer models, we simply BUG(); we want to know if this
 127  * still happens despite the power fixes that have been made!
 128  */
 129 static int dcon_bus_stabilize(struct dcon_priv *dcon, int is_powered_down)
 130 {
 131         unsigned long timeout;
 132         int x;
 133
 134 power_up:
 135         if (is_powered_down) {
 136                 x = 1;
 137                 x = olpc_ec_cmd(0x26, (unsigned char *)&x, 1, NULL, 0);
 138                 if (x) {
 139                         printk(KERN_WARNING "olpc-dcon:  unable to force dcon to power up: %d!\n",
 140                                 x);
 141                         return x;
 142                 }
 143                 msleep(10); /* we'll be conservative */
 144         }
 145
 146         pdata->bus_stabilize_wiggle();
 147
 148         for (x = -1, timeout = 50; timeout && x < 0; timeout--) {
 149                 msleep(1);
 150                 x = dcon_read(dcon, DCON_REG_ID);
 151         }
 152         if (x < 0) {
 153                 printk(KERN_ERR "olpc-dcon:  unable to stabilize dcon's smbus, reasserting power and praying.\n");
 154                 BUG_ON(olpc_board_at_least(olpc_board(0xc2)));
 155                 x = 0;
 156                 olpc_ec_cmd(0x26, (unsigned char *)&x, 1, NULL, 0);
 157                 msleep(100);
 158                 is_powered_down = 1;
 159                 goto power_up;  /* argh, stupid hardware.. */
 160         }
 161
 162         if (is_powered_down)
 163                 return dcon_hw_init(dcon, 0);
 164         return 0;
 165 }
 166
 167 static void dcon_set_backlight(struct dcon_priv *dcon, u8 level)
 168 {
 169         dcon->bl_val = level;
 170         dcon_write(dcon, DCON_REG_BRIGHT, dcon->bl_val);
 171
 172         /* Purposely turn off the backlight when we go to level 0 */
 173         if (dcon->bl_val == 0) {
 174                 dcon->disp_mode &= ~MODE_BL_ENABLE;
 175                 dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
 176         } else if (!(dcon->disp_mode & MODE_BL_ENABLE)) {
 177                 dcon->disp_mode |= MODE_BL_ENABLE;
 178                 dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
 179         }
 180 }
 181
 182 /* Set the output type to either color or mono */
 183 static int dcon_set_mono_mode(struct dcon_priv *dcon, bool enable_mono)
 184 {
 185         if (dcon->mono == enable_mono)
 186                 return 0;
 187
 188         dcon->mono = enable_mono;
 189
 190         if (enable_mono) {
 191                 dcon->disp_mode &= ~(MODE_CSWIZZLE | MODE_COL_AA);
 192                 dcon->disp_mode |= MODE_MONO_LUMA;
 193         } else {
 194                 dcon->disp_mode &= ~(MODE_MONO_LUMA);
 195                 dcon->disp_mode |= MODE_CSWIZZLE;
 196                 if (useaa)
 197                         dcon->disp_mode |= MODE_COL_AA;
 198         }
 199
 200         dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
 201         return 0;
 202 }
 203
 204 /* For now, this will be really stupid - we need to address how
 205  * DCONLOAD works in a sleep and account for it accordingly
 206  */
 207
 208 static void dcon_sleep(struct dcon_priv *dcon, bool sleep)
 209 {
 210         int x;
 211
 212         /* Turn off the backlight and put the DCON to sleep */
 213
 214         if (dcon->asleep == sleep)
 215                 return;
 216
 217         if (!olpc_board_at_least(olpc_board(0xc2)))
 218                 return;
 219
 220         if (sleep) {
 221                 x = 0;
 222                 x = olpc_ec_cmd(0x26, (unsigned char *)&x, 1, NULL, 0);
 223                 if (x)
 224                         printk(KERN_WARNING "olpc-dcon:  unable to force dcon to power down: %d!\n",
 225                                 x);
 226                 else
 227                         dcon->asleep = sleep;
 228         } else {
 229                 /* Only re-enable the backlight if the backlight value is set */
 230                 if (dcon->bl_val != 0)
 231                         dcon->disp_mode |= MODE_BL_ENABLE;
 232                 x = dcon_bus_stabilize(dcon, 1);
 233                 if (x)
 234                         printk(KERN_WARNING "olpc-dcon:  unable to reinit dcon hardware: %d!\n",
 235                                 x);
 236                 else
 237                         dcon->asleep = sleep;
 238
 239                 /* Restore backlight */
 240                 dcon_set_backlight(dcon, dcon->bl_val);
 241         }
 242
 243         /* We should turn off some stuff in the framebuffer - but what? */
 244 }
 245
 246 /* the DCON seems to get confused if we change DCONLOAD too
 247  * frequently -- i.e., approximately faster than frame time.
 248  * normally we don't change it this fast, so in general we won't
 249  * delay here.
 250  */
 251 static void dcon_load_holdoff(struct dcon_priv *dcon)
 252 {
 253         struct timespec delta_t, now;
 254         while (1) {
 255                 getnstimeofday(&now);
 256                 delta_t = timespec_sub(now, dcon->load_time);
 257                 if (delta_t.tv_sec != 0 ||
 258                         delta_t.tv_nsec > NSEC_PER_MSEC * 20) {
 259                         break;
 260                 }
 261                 mdelay(4);
 262         }
 263 }
 264
 265 static bool dcon_blank_fb(struct dcon_priv *dcon, bool blank)
 266 {
 267         int err;
 268
 269         if (!lock_fb_info(dcon->fbinfo)) {
 270                 dev_err(&dcon->client->dev, "unable to lock framebuffer\n");
 271                 return false;
 272         }
 273         console_lock();
 274         dcon->ignore_fb_events = true;
 275         err = fb_blank(dcon->fbinfo,
 276                         blank ? FB_BLANK_POWERDOWN : FB_BLANK_UNBLANK);
 277         dcon->ignore_fb_events = false;
 278         console_unlock();
 279         unlock_fb_info(dcon->fbinfo);
 280
 281         if (err) {
 282                 dev_err(&dcon->client->dev, "couldn't %sblank framebuffer\n",
 283                                 blank ? "" : "un");
 284                 return false;
 285         }
 286         return true;
 287 }
 288
 289 /* Set the source of the display (CPU or DCON) */
 290 static void dcon_source_switch(struct work_struct *work)
 291 {
 292         struct dcon_priv *dcon = container_of(work, struct dcon_priv,
 293                         switch_source);
 294         DECLARE_WAITQUEUE(wait, current);
 295         int source = dcon->pending_src;
 296
 297         if (dcon->curr_src == source)
 298                 return;
 299
 300         dcon_load_holdoff(dcon);
 301
 302         dcon->switched = false;
 303
 304         switch (source) {
 305         case DCON_SOURCE_CPU:
 306                 printk(KERN_INFO "dcon_source_switch to CPU\n");
 307                 /* Enable the scanline interrupt bit */
 308                 if (dcon_write(dcon, DCON_REG_MODE,
 309                                 dcon->disp_mode | MODE_SCAN_INT))
 310                         printk(KERN_ERR
 311                                "olpc-dcon:  couldn't enable scanline interrupt!\n");
 312                 else {
 313                         /* Wait up to one second for the scanline interrupt */
 314                         wait_event_timeout(dcon_wait_queue,
 315                                            dcon->switched == true, HZ);
 316                 }
 317
 318                 if (!dcon->switched)
 319                         printk(KERN_ERR "olpc-dcon:  Timeout entering CPU mode; expect a screen glitch.\n");
 320
 321                 /* Turn off the scanline interrupt */
 322                 if (dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode))
 323                         printk(KERN_ERR "olpc-dcon:  couldn't disable scanline interrupt!\n");
 324
 325                 /*
 326                  * Ideally we'd like to disable interrupts here so that the
 327                  * fb unblanking and DCON turn on happen at a known time value;
 328                  * however, we can't do that right now with fb_blank
 329                  * messing with semaphores.
 330                  *
 331                  * For now, we just hope..
 332                  */
 333                 if (!dcon_blank_fb(dcon, false)) {
 334                         printk(KERN_ERR "olpc-dcon:  Failed to enter CPU mode\n");
 335                         dcon->pending_src = DCON_SOURCE_DCON;
 336                         return;
 337                 }
 338
 339                 /* And turn off the DCON */
 340                 pdata->set_dconload(1);
 341                 getnstimeofday(&dcon->load_time);
 342
 343                 printk(KERN_INFO "olpc-dcon: The CPU has control\n");
 344                 break;
 345         case DCON_SOURCE_DCON:
 346         {
 347                 int t;
 348                 struct timespec delta_t;
 349
 350                 printk(KERN_INFO "dcon_source_switch to DCON\n");
 351
 352                 add_wait_queue(&dcon_wait_queue, &wait);
 353                 set_current_state(TASK_UNINTERRUPTIBLE);
 354
 355                 /* Clear DCONLOAD - this implies that the DCON is in control */
 356                 pdata->set_dconload(0);
 357                 getnstimeofday(&dcon->load_time);
 358
 359                 t = schedule_timeout(HZ/2);
 360                 remove_wait_queue(&dcon_wait_queue, &wait);
 361                 set_current_state(TASK_RUNNING);
 362
 363                 if (!dcon->switched) {
 364                         printk(KERN_ERR "olpc-dcon: Timeout entering DCON mode; expect a screen glitch.\n");
 365                 } else {
 366                         /* sometimes the DCON doesn't follow its own rules,
 367                          * and doesn't wait for two vsync pulses before
 368                          * ack'ing the frame load with an IRQ.  the result
 369                          * is that the display shows the *previously*
 370                          * loaded frame.  we can detect this by looking at
 371                          * the time between asserting DCONLOAD and the IRQ --
 372                          * if it's less than 20msec, then the DCON couldn't
 373                          * have seen two VSYNC pulses.  in that case we
 374                          * deassert and reassert, and hope for the best.
 375                          * see http://dev.laptop.org/ticket/9664
 376                          */
 377                         delta_t = timespec_sub(dcon->irq_time, dcon->load_time);
 378                         if (dcon->switched && delta_t.tv_sec == 0 &&
 379                                         delta_t.tv_nsec < NSEC_PER_MSEC * 20) {
 380                                 printk(KERN_ERR "olpc-dcon: missed loading, retrying\n");
 381                                 pdata->set_dconload(1);
 382                                 mdelay(41);
 383                                 pdata->set_dconload(0);
 384                                 getnstimeofday(&dcon->load_time);
 385                                 mdelay(41);
 386                         }
 387                 }
 388
 389                 dcon_blank_fb(dcon, true);
 390                 printk(KERN_INFO "olpc-dcon: The DCON has control\n");
 391                 break;
 392         }
 393         default:
 394                 BUG();
 395         }
 396
 397         dcon->curr_src = source;
 398 }
 399
 400 static void dcon_set_source(struct dcon_priv *dcon, int arg)
 401 {
 402         if (dcon->pending_src == arg)
 403                 return;
 404
 405         dcon->pending_src = arg;
 406
 407         if ((dcon->curr_src != arg) && !work_pending(&dcon->switch_source))
 408                 schedule_work(&dcon->switch_source);
 409 }
 410
 411 static void dcon_set_source_sync(struct dcon_priv *dcon, int arg)
 412 {
 413         dcon_set_source(dcon, arg);
 414         flush_scheduled_work();
 415 }
 416
 417 static ssize_t dcon_mode_show(struct device *dev,
 418         struct device_attribute *attr, char *buf)
 419 {
 420         struct dcon_priv *dcon = dev_get_drvdata(dev);
 421         return sprintf(buf, "%4.4X\n", dcon->disp_mode);
 422 }
 423
 424 static ssize_t dcon_sleep_show(struct device *dev,
 425         struct device_attribute *attr, char *buf)
 426 {
 427
 428         struct dcon_priv *dcon = dev_get_drvdata(dev);
 429         return sprintf(buf, "%d\n", dcon->asleep);
 430 }
 431
 432 static ssize_t dcon_freeze_show(struct device *dev,
 433         struct device_attribute *attr, char *buf)
 434 {
 435         struct dcon_priv *dcon = dev_get_drvdata(dev);
 436         return sprintf(buf, "%d\n", dcon->curr_src == DCON_SOURCE_DCON ? 1 : 0);
 437 }
 438
 439 static ssize_t dcon_mono_show(struct device *dev,
 440         struct device_attribute *attr, char *buf)
 441 {
 442         struct dcon_priv *dcon = dev_get_drvdata(dev);
 443         return sprintf(buf, "%d\n", dcon->mono);
 444 }
 445
 446 static ssize_t dcon_resumeline_show(struct device *dev,
 447         struct device_attribute *attr, char *buf)
 448 {
 449         return sprintf(buf, "%d\n", resumeline);
 450 }
 451
 452 static ssize_t dcon_mono_store(struct device *dev,
 453         struct device_attribute *attr, const char *buf, size_t count)
 454 {
 455         unsigned long enable_mono;
 456         int rc;
 457
 458         rc = kstrtoul(buf, 10, &enable_mono);
 459         if (rc)
 460                 return rc;
 461
 462         dcon_set_mono_mode(dev_get_drvdata(dev), enable_mono ? true : false);
 463
 464         return count;
 465 }
 466
 467 static ssize_t dcon_freeze_store(struct device *dev,
 468         struct device_attribute *attr, const char *buf, size_t count)
 469 {
 470         struct dcon_priv *dcon = dev_get_drvdata(dev);
 471         unsigned long output;
 472         int ret;
 473
 474         ret = kstrtoul(buf, 10, &output);
 475         if (ret)
 476                 return ret;
 477
 478         printk(KERN_INFO "dcon_freeze_store: %lu\n", output);
 479
 480         switch (output) {
 481         case 0:
 482                 dcon_set_source(dcon, DCON_SOURCE_CPU);
 483                 break;
 484         case 1:
 485                 dcon_set_source_sync(dcon, DCON_SOURCE_DCON);
 486                 break;
 487         case 2:  /* normally unused */
 488                 dcon_set_source(dcon, DCON_SOURCE_DCON);
 489                 break;
 490         default:
 491                 return -EINVAL;
 492         }
 493
 494         return count;
 495 }
 496
 497 static ssize_t dcon_resumeline_store(struct device *dev,
 498         struct device_attribute *attr, const char *buf, size_t count)
 499 {
 500         unsigned short rl;
 501         int rc;
 502
 503         rc = kstrtou16(buf, 10, &rl);
 504         if (rc)
 505                 return rc;
 506
 507         resumeline = rl;
 508         dcon_write(dev_get_drvdata(dev), DCON_REG_SCAN_INT, resumeline);
 509
 510         return count;
 511 }
 512
 513 static ssize_t dcon_sleep_store(struct device *dev,
 514         struct device_attribute *attr, const char *buf, size_t count)
 515 {
 516         unsigned long output;
 517         int ret;
 518
 519         ret = kstrtoul(buf, 10, &output);
 520         if (ret)
 521                 return ret;
 522
 523         dcon_sleep(dev_get_drvdata(dev), output ? true : false);
 524         return count;
 525 }
 526
 527 static struct device_attribute dcon_device_files[] = {
 528         __ATTR(mode, 0444, dcon_mode_show, NULL),
 529         __ATTR(sleep, 0644, dcon_sleep_show, dcon_sleep_store),
 530         __ATTR(freeze, 0644, dcon_freeze_show, dcon_freeze_store),
 531         __ATTR(monochrome, 0644, dcon_mono_show, dcon_mono_store),
 532         __ATTR(resumeline, 0644, dcon_resumeline_show, dcon_resumeline_store),
 533 };
 534
 535 static int dcon_bl_update(struct backlight_device *dev)
 536 {
 537         struct dcon_priv *dcon = bl_get_data(dev);
 538         u8 level = dev->props.brightness & 0x0F;
 539
 540         if (dev->props.power != FB_BLANK_UNBLANK)
 541                 level = 0;
 542
 543         if (level != dcon->bl_val)
 544                 dcon_set_backlight(dcon, level);
 545
 546         return 0;
 547 }
 548
 549 static int dcon_bl_get(struct backlight_device *dev)
 550 {
 551         struct dcon_priv *dcon = bl_get_data(dev);
 552         return dcon->bl_val;
 553 }
 554
 555 static const struct backlight_ops dcon_bl_ops = {
 556         .update_status = dcon_bl_update,
 557         .get_brightness = dcon_bl_get,
 558 };
 559
 560 static struct backlight_properties dcon_bl_props = {
 561         .max_brightness = 15,
 562         .type = BACKLIGHT_RAW,
 563         .power = FB_BLANK_UNBLANK,
 564 };
 565
 566 static int dcon_reboot_notify(struct notifier_block *nb,
 567                               unsigned long foo, void *bar)
 568 {
 569         struct dcon_priv *dcon = container_of(nb, struct dcon_priv, reboot_nb);
 570
 571         if (!dcon || !dcon->client)
 572                 return 0;
 573
 574         /* Turn off the DCON. Entirely. */
 575         dcon_write(dcon, DCON_REG_MODE, 0x39);
 576         dcon_write(dcon, DCON_REG_MODE, 0x32);
 577         return 0;
 578 }
 579
 580 static int unfreeze_on_panic(struct notifier_block *nb,
 581                              unsigned long e, void *p)
 582 {
 583         pdata->set_dconload(1);
 584         return NOTIFY_DONE;
 585 }
 586
 587 static struct notifier_block dcon_panic_nb = {
 588         .notifier_call = unfreeze_on_panic,
 589 };
 590
 591 /*
 592  * When the framebuffer sleeps due to external sources (e.g. user idle), power
 593  * down the DCON as well.  Power it back up when the fb comes back to life.
 594  */
 595 static int dcon_fb_notifier(struct notifier_block *self,
 596                                 unsigned long event, void *data)
 597 {
 598         struct fb_event *evdata = data;
 599         struct dcon_priv *dcon = container_of(self, struct dcon_priv,
 600                         fbevent_nb);
 601         int *blank = (int *)evdata->data;
 602         if (((event != FB_EVENT_BLANK) && (event != FB_EVENT_CONBLANK)) ||
 603                         dcon->ignore_fb_events)
 604                 return 0;
 605         dcon_sleep(dcon, *blank ? true : false);
 606         return 0;
 607 }
 608
 609 static int dcon_detect(struct i2c_client *client, struct i2c_board_info *info)
 610 {
 611         strlcpy(info->type, "olpc_dcon", I2C_NAME_SIZE);
 612
 613         return 0;
 614 }
 615
 616 static int dcon_probe(struct i2c_client *client, const struct i2c_device_id *id)
 617 {
 618         struct dcon_priv *dcon;
 619         int rc, i, j;
 620
 621         if (!pdata)
 622                 return -ENXIO;
 623
 624         dcon = kzalloc(sizeof(*dcon), GFP_KERNEL);
 625         if (!dcon)
 626                 return -ENOMEM;
 627
 628         dcon->client = client;
 629         INIT_WORK(&dcon->switch_source, dcon_source_switch);
 630         dcon->reboot_nb.notifier_call = dcon_reboot_notify;
 631         dcon->reboot_nb.priority = -1;
 632         dcon->fbevent_nb.notifier_call = dcon_fb_notifier;
 633
 634         i2c_set_clientdata(client, dcon);
 635
 636         if (num_registered_fb < 1) {
 637                 dev_err(&client->dev, "DCON driver requires a registered fb\n");
 638                 rc = -EIO;
 639                 goto einit;
 640         }
 641         dcon->fbinfo = registered_fb[0];
 642
 643         rc = dcon_hw_init(dcon, 1);
 644         if (rc)
 645                 goto einit;
 646
 647         /* Add the DCON device */
 648
 649         dcon_device = platform_device_alloc("dcon", -1);
 650
 651         if (dcon_device == NULL) {
 652                 printk(KERN_ERR "dcon:  Unable to create the DCON device\n");
 653                 rc = -ENOMEM;
 654                 goto eirq;
 655         }
 656         rc = platform_device_add(dcon_device);
 657         platform_set_drvdata(dcon_device, dcon);
 658
 659         if (rc) {
 660                 printk(KERN_ERR "dcon:  Unable to add the DCON device\n");
 661                 goto edev;
 662         }
 663
 664         for (i = 0; i < ARRAY_SIZE(dcon_device_files); i++) {
 665                 rc = device_create_file(&dcon_device->dev,
 666                                         &dcon_device_files[i]);
 667                 if (rc) {
 668                         dev_err(&dcon_device->dev, "Cannot create sysfs file\n");
 669                         goto ecreate;
 670                 }
 671         }
 672
 673         dcon->bl_val = dcon_read(dcon, DCON_REG_BRIGHT) & 0x0F;
 674
 675         /* Add the backlight device for the DCON */
 676         dcon_bl_props.brightness = dcon->bl_val;
 677         dcon->bl_dev = backlight_device_register("dcon-bl", &dcon_device->dev,
 678                 dcon, &dcon_bl_ops, &dcon_bl_props);
 679         if (IS_ERR(dcon->bl_dev)) {
 680                 dev_err(&client->dev, "cannot register backlight dev (%ld)\n",
 681                                 PTR_ERR(dcon->bl_dev));
 682                 dcon->bl_dev = NULL;
 683         }
 684
 685         register_reboot_notifier(&dcon->reboot_nb);
 686         atomic_notifier_chain_register(&panic_notifier_list, &dcon_panic_nb);
 687         fb_register_client(&dcon->fbevent_nb);
 688
 689         return 0;
 690
 691  ecreate:
 692         for (j = 0; j < i; j++)
 693                 device_remove_file(&dcon_device->dev, &dcon_device_files[j]);
 694  edev:
 695         platform_device_unregister(dcon_device);
 696         dcon_device = NULL;
 697  eirq:
 698         free_irq(DCON_IRQ, dcon);
 699  einit:
 700         kfree(dcon);
 701         return rc;
 702 }
 703
 704 static int dcon_remove(struct i2c_client *client)
 705 {
 706         struct dcon_priv *dcon = i2c_get_clientdata(client);
 707
 708         fb_unregister_client(&dcon->fbevent_nb);
 709         unregister_reboot_notifier(&dcon->reboot_nb);
 710         atomic_notifier_chain_unregister(&panic_notifier_list, &dcon_panic_nb);
 711
 712         free_irq(DCON_IRQ, dcon);
 713
 714         if (dcon->bl_dev)
 715                 backlight_device_unregister(dcon->bl_dev);
 716
 717         if (dcon_device != NULL)
 718                 platform_device_unregister(dcon_device);
 719         cancel_work_sync(&dcon->switch_source);
 720
 721         kfree(dcon);
 722
 723         return 0;
 724 }
 725
 726 #ifdef CONFIG_PM
 727 static int dcon_suspend(struct i2c_client *client, pm_message_t state)
 728 {
 729         struct dcon_priv *dcon = i2c_get_clientdata(client);
 730
 731         if (!dcon->asleep) {
 732                 /* Set up the DCON to have the source */
 733                 dcon_set_source_sync(dcon, DCON_SOURCE_DCON);
 734         }
 735
 736         return 0;
 737 }
 738
 739 static int dcon_resume(struct i2c_client *client)
 740 {
 741         struct dcon_priv *dcon = i2c_get_clientdata(client);
 742
 743         if (!dcon->asleep) {
 744                 dcon_bus_stabilize(dcon, 0);
 745                 dcon_set_source(dcon, DCON_SOURCE_CPU);
 746         }
 747
 748         return 0;
 749 }
 750
 751 #endif
 752
 753
 754 irqreturn_t dcon_interrupt(int irq, void *id)
 755 {
 756         struct dcon_priv *dcon = id;
 757         u8 status;
 758
 759         if (pdata->read_status(&status))
 760                 return IRQ_NONE;
 761
 762         switch (status & 3) {
 763         case 3:
 764                 printk(KERN_DEBUG "olpc-dcon: DCONLOAD_MISSED interrupt\n");
 765                 break;
 766
 767         case 2: /* switch to DCON mode */
 768         case 1: /* switch to CPU mode */
 769                 dcon->switched = true;
 770                 getnstimeofday(&dcon->irq_time);
 771                 wake_up(&dcon_wait_queue);
 772                 break;
 773
 774         case 0:
 775                 /* workaround resume case:  the DCON (on 1.5) doesn't
 776                  * ever assert status 0x01 when switching to CPU mode
 777                  * during resume.  this is because DCONLOAD is de-asserted
 778                  * _immediately_ upon exiting S3, so the actual release
 779                  * of the DCON happened long before this point.
 780                  * see http://dev.laptop.org/ticket/9869
 781                  */
 782                 if (dcon->curr_src != dcon->pending_src && !dcon->switched) {
 783                         dcon->switched = true;
 784                         getnstimeofday(&dcon->irq_time);
 785                         wake_up(&dcon_wait_queue);
 786                         printk(KERN_DEBUG "olpc-dcon: switching w/ status 0/0\n");
 787                 } else {
 788                         printk(KERN_DEBUG "olpc-dcon: scanline interrupt w/CPU\n");
 789                 }
 790         }
 791
 792         return IRQ_HANDLED;
 793 }
 794
 795 static const struct i2c_device_id dcon_idtable[] = {
 796         { "olpc_dcon",  0 },
 797         { }
 798 };
 799
 800 MODULE_DEVICE_TABLE(i2c, dcon_idtable);
 801
 802 struct i2c_driver dcon_driver = {
 803         .driver = {
 804                 .name   = "olpc_dcon",
 805         },
 806         .class = I2C_CLASS_DDC | I2C_CLASS_HWMON,
 807         .id_table = dcon_idtable,
 808         .probe = dcon_probe,
 809         .remove = __devexit_p(dcon_remove),
 810         .detect = dcon_detect,
 811         .address_list = normal_i2c,
 812 #ifdef CONFIG_PM
 813         .suspend = dcon_suspend,
 814         .resume = dcon_resume,
 815 #endif
 816 };
 817
 818 static int __init olpc_dcon_init(void)
 819 {
 820 #ifdef CONFIG_FB_OLPC_DCON_1_5
 821         /* XO-1.5 */
 822         if (olpc_board_at_least(olpc_board(0xd0)))
 823                 pdata = &dcon_pdata_xo_1_5;
 824 #endif
 825 #ifdef CONFIG_FB_OLPC_DCON_1
 826         if (!pdata)
 827                 pdata = &dcon_pdata_xo_1;
 828 #endif
 829
 830         return i2c_add_driver(&dcon_driver);
 831 }
 832
 833 static void __exit olpc_dcon_exit(void)
 834 {
 835         i2c_del_driver(&dcon_driver);
 836 }
 837
 838 module_init(olpc_dcon_init);
 839 module_exit(olpc_dcon_exit);
 840
 841 MODULE_LICENSE("GPL");