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  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/backlight.h>
  25 #include <linux/device.h>
  26 #include <linux/notifier.h>
  27 #include <asm/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 int resumeline = 898;
  38 module_param(resumeline, int, 0444);
  39
  40 static int noinit;
  41 module_param(noinit, int, 0444);
  42
  43 /* Default off since it doesn't work on DCON ASIC in B-test OLPC board */
  44 static int useaa = 1;
  45 module_param(useaa, int, 0444);
  46
  47 struct dcon_platform_data {
  48         int (*init)(void);
  49         void (*bus_stabilize_wiggle)(void);
  50         void (*set_dconload)(int);
  51         u8 (*read_status)(void);
  52 };
  53
  54 static struct dcon_platform_data *pdata;
  55
  56 /* I2C structures */
  57
  58 static struct i2c_driver dcon_driver;
  59 static struct i2c_client *dcon_client;
  60
  61 /* Platform devices */
  62 static struct platform_device *dcon_device;
  63
  64 /* Backlight device */
  65 static struct backlight_device *dcon_bl_dev;
  66
  67 static struct fb_info *fbinfo;
  68
  69 /* set this to 1 while controlling fb blank state from this driver */
  70 static int ignore_fb_events = 0;
  71
  72 /* Current source, initialized at probe time */
  73 static int dcon_source;
  74
  75 /* Desired source */
  76 static int dcon_pending;
  77
  78 /* Current output type */
  79 static int dcon_output = DCON_OUTPUT_COLOR;
  80
  81 /* Current sleep status (not yet implemented) */
  82 static int dcon_sleep_val = DCON_ACTIVE;
  83
  84 /* Shadow register for the DCON_REG_MODE register */
  85 static unsigned short dcon_disp_mode;
  86
  87 /* Variables used during switches */
  88 static int dcon_switched;
  89 static struct timespec dcon_irq_time;
  90 static struct timespec dcon_load_time;
  91
  92 static DECLARE_WAIT_QUEUE_HEAD(dcon_wait_queue);
  93
  94 static unsigned short normal_i2c[] = { 0x0d, I2C_CLIENT_END };
  95
  96 #define dcon_write(reg,val) i2c_smbus_write_word_data(dcon_client,reg,val)
  97 #define dcon_read(reg) i2c_smbus_read_word_data(dcon_client,reg)
  98
  99 /* The current backlight value - this saves us some smbus traffic */
 100 static int bl_val = -1;
 101
 102 /* ===== API functions - these are called by a variety of users ==== */
 103
 104 static int dcon_hw_init(struct i2c_client *client, int is_init)
 105 {
 106         uint16_t ver;
 107         int rc = 0;
 108
 109         ver = i2c_smbus_read_word_data(client, DCON_REG_ID);
 110         if ((ver >> 8) != 0xDC) {
 111                 printk(KERN_ERR "olpc-dcon:  DCON ID not 0xDCxx: 0x%04x "
 112                                 "instead.\n", ver);
 113                 rc = -ENXIO;
 114                 goto err;
 115         }
 116
 117         if (is_init) {
 118                 printk(KERN_INFO "olpc-dcon:  Discovered DCON version %x\n",
 119                                 ver & 0xFF);
 120                 if ((rc = pdata->init()) != 0) {
 121                         printk(KERN_ERR "olpc-dcon:  Unable to init.\n");
 122                         goto err;
 123                 }
 124         }
 125
 126         if (ver < 0xdc02 && !noinit) {
 127                 /* Initialize the DCON registers */
 128
 129                 /* Start with work-arounds for DCON ASIC */
 130                 i2c_smbus_write_word_data(client, 0x4b, 0x00cc);
 131                 i2c_smbus_write_word_data(client, 0x4b, 0x00cc);
 132                 i2c_smbus_write_word_data(client, 0x4b, 0x00cc);
 133                 i2c_smbus_write_word_data(client, 0x0b, 0x007a);
 134                 i2c_smbus_write_word_data(client, 0x36, 0x025c);
 135                 i2c_smbus_write_word_data(client, 0x37, 0x025e);
 136
 137                 /* Initialise SDRAM */
 138
 139                 i2c_smbus_write_word_data(client, 0x3b, 0x002b);
 140                 i2c_smbus_write_word_data(client, 0x41, 0x0101);
 141                 i2c_smbus_write_word_data(client, 0x42, 0x0101);
 142         }
 143         else if (!noinit) {
 144                 /* SDRAM setup/hold time */
 145                 i2c_smbus_write_word_data(client, 0x3a, 0xc040);
 146                 i2c_smbus_write_word_data(client, 0x41, 0x0000);
 147                 i2c_smbus_write_word_data(client, 0x41, 0x0101);
 148                 i2c_smbus_write_word_data(client, 0x42, 0x0101);
 149         }
 150
 151         /* Colour swizzle, AA, no passthrough, backlight */
 152         if (is_init) {
 153                 dcon_disp_mode = MODE_PASSTHRU | MODE_BL_ENABLE | MODE_CSWIZZLE;
 154                 if (useaa)
 155                         dcon_disp_mode |= MODE_COL_AA;
 156         }
 157         i2c_smbus_write_word_data(client, DCON_REG_MODE, dcon_disp_mode);
 158
 159
 160         /* Set the scanline to interrupt on during resume */
 161         i2c_smbus_write_word_data(client, DCON_REG_SCAN_INT, resumeline);
 162
 163 err:
 164         return rc;
 165 }
 166
 167 /*
 168  * The smbus doesn't always come back due to what is believed to be
 169  * hardware (power rail) bugs.  For older models where this is known to
 170  * occur, our solution is to attempt to wait for the bus to stabilize;
 171  * if it doesn't happen, cut power to the dcon, repower it, and wait
 172  * for the bus to stabilize.  Rinse, repeat until we have a working
 173  * smbus.  For newer models, we simply BUG(); we want to know if this
 174  * still happens despite the power fixes that have been made!
 175  */
 176 static int dcon_bus_stabilize(struct i2c_client *client, int is_powered_down)
 177 {
 178         unsigned long timeout;
 179         int x;
 180
 181 power_up:
 182         if (is_powered_down) {
 183                 x = 1;
 184                 if ((x = olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0))) {
 185                         printk(KERN_WARNING "olpc-dcon:  unable to force dcon "
 186                                         "to power up: %d!\n", x);
 187                         return x;
 188                 }
 189                 msleep(10); /* we'll be conservative */
 190         }
 191
 192         pdata->bus_stabilize_wiggle();
 193
 194         for (x = -1, timeout = 50; timeout && x < 0; timeout--) {
 195                 msleep(1);
 196                 x = dcon_read(DCON_REG_ID);
 197         }
 198         if (x < 0) {
 199                 printk(KERN_ERR "olpc-dcon:  unable to stabilize dcon's "
 200                                 "smbus, reasserting power and praying.\n");
 201                 BUG_ON(olpc_board_at_least(olpc_board(0xc2)));
 202                 x = 0;
 203                 olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0);
 204                 msleep(100);
 205                 is_powered_down = 1;
 206                 goto power_up;  /* argh, stupid hardware.. */
 207         }
 208
 209         if (is_powered_down)
 210                 return dcon_hw_init(client, 0);
 211         return 0;
 212 }
 213
 214 static int dcon_get_backlight(void)
 215 {
 216         if (dcon_client == NULL)
 217                 return 0;
 218
 219         if (bl_val == -1)
 220                 bl_val = dcon_read(DCON_REG_BRIGHT) & 0x0F;
 221
 222         return bl_val;
 223 }
 224
 225
 226 static void dcon_set_backlight_hw(int level)
 227 {
 228         bl_val = level & 0x0F;
 229         dcon_write(DCON_REG_BRIGHT, bl_val);
 230
 231         /* Purposely turn off the backlight when we go to level 0 */
 232         if (bl_val == 0) {
 233                 dcon_disp_mode &= ~MODE_BL_ENABLE;
 234                 dcon_write(DCON_REG_MODE, dcon_disp_mode);
 235         } else if (!(dcon_disp_mode & MODE_BL_ENABLE)) {
 236                 dcon_disp_mode |= MODE_BL_ENABLE;
 237                 dcon_write(DCON_REG_MODE, dcon_disp_mode);
 238         }
 239 }
 240
 241 static void dcon_set_backlight(int level)
 242 {
 243         if (dcon_client == NULL)
 244                 return;
 245
 246         if (bl_val == (level & 0x0F))
 247                 return;
 248
 249         dcon_set_backlight_hw(level);
 250 }
 251
 252 /* Set the output type to either color or mono */
 253
 254 static int dcon_set_output(int arg)
 255 {
 256         if (dcon_output == arg)
 257                 return 0;
 258
 259         dcon_output = arg;
 260
 261         if (arg == DCON_OUTPUT_MONO) {
 262                 dcon_disp_mode &= ~(MODE_CSWIZZLE | MODE_COL_AA);
 263                 dcon_disp_mode |= MODE_MONO_LUMA;
 264         }
 265         else {
 266                 dcon_disp_mode &= ~(MODE_MONO_LUMA);
 267                 dcon_disp_mode |= MODE_CSWIZZLE;
 268                 if (useaa)
 269                         dcon_disp_mode |= MODE_COL_AA;
 270         }
 271
 272         dcon_write(DCON_REG_MODE, dcon_disp_mode);
 273         return 0;
 274 }
 275
 276 /* For now, this will be really stupid - we need to address how
 277  * DCONLOAD works in a sleep and account for it accordingly
 278  */
 279
 280 static void dcon_sleep(int state)
 281 {
 282         int x;
 283
 284         /* Turn off the backlight and put the DCON to sleep */
 285
 286         if (state == dcon_sleep_val)
 287                 return;
 288
 289         if (!olpc_board_at_least(olpc_board(0xc2)))
 290                 return;
 291
 292         if (state == DCON_SLEEP) {
 293                 x = 0;
 294                 if ((x = olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0)))
 295                         printk(KERN_WARNING "olpc-dcon:  unable to force dcon "
 296                                         "to power down: %d!\n", x);
 297                 else
 298                         dcon_sleep_val = state;
 299         }
 300         else {
 301                 /* Only re-enable the backlight if the backlight value is set */
 302                 if (bl_val != 0)
 303                         dcon_disp_mode |= MODE_BL_ENABLE;
 304
 305                 if ((x=dcon_bus_stabilize(dcon_client, 1)))
 306                         printk(KERN_WARNING "olpc-dcon:  unable to reinit dcon"
 307                                         " hardware: %d!\n", x);
 308                 else
 309                         dcon_sleep_val = state;
 310
 311                 /* Restore backlight */
 312                 dcon_set_backlight_hw(bl_val);
 313         }
 314
 315         /* We should turn off some stuff in the framebuffer - but what? */
 316 }
 317
 318 /* the DCON seems to get confused if we change DCONLOAD too
 319  * frequently -- i.e., approximately faster than frame time.
 320  * normally we don't change it this fast, so in general we won't
 321  * delay here.
 322  */
 323 void dcon_load_holdoff(void)
 324 {
 325         struct timespec delta_t, now;
 326         while(1) {
 327                 getnstimeofday(&now);
 328                 delta_t = timespec_sub(now, dcon_load_time);
 329                 if (delta_t.tv_sec != 0 ||
 330                         delta_t.tv_nsec > NSEC_PER_MSEC * 20) {
 331                         break;
 332                 }
 333                 mdelay(4);
 334         }
 335 }
 336 /* Set the source of the display (CPU or DCON) */
 337
 338 static void dcon_source_switch(struct work_struct *work)
 339 {
 340         DECLARE_WAITQUEUE(wait, current);
 341         int source = dcon_pending;
 342
 343         if (dcon_source == source)
 344                 return;
 345
 346         dcon_load_holdoff();
 347
 348         dcon_switched = 0;
 349
 350         switch (source) {
 351         case DCON_SOURCE_CPU:
 352                 printk("dcon_source_switch to CPU\n");
 353                 /* Enable the scanline interrupt bit */
 354                 if (dcon_write(DCON_REG_MODE, dcon_disp_mode | MODE_SCAN_INT))
 355                         printk(KERN_ERR "olpc-dcon:  couldn't enable scanline interrupt!\n");
 356                 else {
 357                         /* Wait up to one second for the scanline interrupt */
 358                         wait_event_timeout(dcon_wait_queue, dcon_switched == 1, HZ);
 359                 }
 360
 361                 if (!dcon_switched)
 362                         printk(KERN_ERR "olpc-dcon:  Timeout entering CPU mode; expect a screen glitch.\n");
 363
 364                 /* Turn off the scanline interrupt */
 365                 if (dcon_write(DCON_REG_MODE, dcon_disp_mode))
 366                         printk(KERN_ERR "olpc-dcon:  couldn't disable scanline interrupt!\n");
 367
 368                 /*
 369                  * Ideally we'd like to disable interrupts here so that the
 370                  * fb unblanking and DCON turn on happen at a known time value;
 371                  * however, we can't do that right now with fb_blank
 372                  * messing with semaphores.
 373                  *
 374                  * For now, we just hope..
 375                  */
 376                 console_lock();
 377                 ignore_fb_events = 1;
 378                 if (fb_blank(fbinfo, FB_BLANK_UNBLANK)) {
 379                         ignore_fb_events = 0;
 380                         console_unlock();
 381                         printk(KERN_ERR "olpc-dcon:  Failed to enter CPU mode\n");
 382                         dcon_pending = DCON_SOURCE_DCON;
 383                         return;
 384                 }
 385                 ignore_fb_events = 0;
 386                 console_unlock();
 387
 388                 /* And turn off the DCON */
 389                 pdata->set_dconload(1);
 390                 getnstimeofday(&dcon_load_time);
 391
 392                 printk(KERN_INFO "olpc-dcon: The CPU has control\n");
 393                 break;
 394         case DCON_SOURCE_DCON:
 395         {
 396                 int t;
 397                 struct timespec delta_t;
 398
 399                 printk("dcon_source_switch to DCON\n");
 400
 401                 add_wait_queue(&dcon_wait_queue, &wait);
 402                 set_current_state(TASK_UNINTERRUPTIBLE);
 403
 404                 /* Clear DCONLOAD - this implies that the DCON is in control */
 405                 pdata->set_dconload(0);
 406                 getnstimeofday(&dcon_load_time);
 407
 408                 t = schedule_timeout(HZ/2);
 409                 remove_wait_queue(&dcon_wait_queue, &wait);
 410                 set_current_state(TASK_RUNNING);
 411
 412                 if (!dcon_switched) {
 413                         printk(KERN_ERR "olpc-dcon: Timeout entering DCON mode; expect a screen glitch.\n");
 414                 } else {
 415                         /* sometimes the DCON doesn't follow its own rules,
 416                          * and doesn't wait for two vsync pulses before
 417                          * ack'ing the frame load with an IRQ.  the result
 418                          * is that the display shows the *previously*
 419                          * loaded frame.  we can detect this by looking at
 420                          * the time between asserting DCONLOAD and the IRQ --
 421                          * if it's less than 20msec, then the DCON couldn't
 422                          * have seen two VSYNC pulses.  in that case we
 423                          * deassert and reassert, and hope for the best.
 424                          * see http://dev.laptop.org/ticket/9664
 425                          */
 426                         delta_t = timespec_sub(dcon_irq_time, dcon_load_time);
 427                         if (dcon_switched && delta_t.tv_sec == 0 &&
 428                                         delta_t.tv_nsec < NSEC_PER_MSEC * 20) {
 429                                 printk(KERN_ERR "olpc-dcon: missed loading, retrying\n");
 430                                 pdata->set_dconload(1);
 431                                 mdelay(41);
 432                                 pdata->set_dconload(0);
 433                                 getnstimeofday(&dcon_load_time);
 434                                 mdelay(41);
 435                         }
 436                 }
 437
 438                 console_lock();
 439                 ignore_fb_events = 1;
 440                 if (fb_blank(fbinfo, FB_BLANK_POWERDOWN))
 441                         printk(KERN_ERR "olpc-dcon:  couldn't blank fb!\n");
 442                 ignore_fb_events = 0;
 443                 console_unlock();
 444
 445                 printk(KERN_INFO "olpc-dcon: The DCON has control\n");
 446                 break;
 447         }
 448         default:
 449                 BUG();
 450         }
 451
 452         dcon_source = source;
 453 }
 454
 455 static DECLARE_WORK(dcon_work, dcon_source_switch);
 456
 457 static void dcon_set_source(int arg)
 458 {
 459         if (dcon_pending == arg)
 460                 return;
 461
 462         dcon_pending = arg;
 463
 464         if ((dcon_source != arg) && !work_pending(&dcon_work))
 465                 schedule_work(&dcon_work);
 466 }
 467
 468 static void dcon_set_source_sync(int arg)
 469 {
 470         dcon_set_source(arg);
 471         flush_scheduled_work();
 472 }
 473
 474 static int dconbl_set(struct backlight_device *dev) {
 475
 476         int level = dev->props.brightness;
 477
 478         if (dev->props.power != FB_BLANK_UNBLANK)
 479                 level = 0;
 480
 481         dcon_set_backlight(level);
 482         return 0;
 483 }
 484
 485 static int dconbl_get(struct backlight_device *dev) {
 486         return dcon_get_backlight();
 487 }
 488
 489 static ssize_t dcon_mode_show(struct device *dev,
 490         struct device_attribute *attr, char *buf)
 491 {
 492         return sprintf(buf, "%4.4X\n", dcon_disp_mode);
 493 }
 494
 495 static ssize_t dcon_sleep_show(struct device *dev,
 496         struct device_attribute *attr, char *buf)
 497 {
 498
 499         return sprintf(buf, "%d\n", dcon_sleep_val);
 500 }
 501
 502 static ssize_t dcon_freeze_show(struct device *dev,
 503         struct device_attribute *attr, char *buf)
 504 {
 505         return sprintf(buf, "%d\n", dcon_source == DCON_SOURCE_DCON ? 1 : 0);
 506 }
 507
 508 static ssize_t dcon_output_show(struct device *dev,
 509         struct device_attribute *attr, char *buf)
 510 {
 511         return sprintf(buf, "%d\n", dcon_output);
 512 }
 513
 514 static ssize_t dcon_resumeline_show(struct device *dev,
 515         struct device_attribute *attr, char *buf)
 516 {
 517         return sprintf(buf, "%d\n", resumeline);
 518 }
 519
 520 static int _strtoul(const char *buf, int len, unsigned int *val)
 521 {
 522
 523         char *endp;
 524         unsigned int output = simple_strtoul(buf, &endp, 0);
 525         int size = endp - buf;
 526
 527         if (*endp && isspace(*endp))
 528                 size++;
 529
 530         if (size != len)
 531                 return -EINVAL;
 532
 533         *val = output;
 534         return 0;
 535 }
 536
 537 static ssize_t dcon_output_store(struct device *dev,
 538         struct device_attribute *attr, const char *buf, size_t count)
 539 {
 540         int output;
 541         int rc = -EINVAL;
 542
 543         if (_strtoul(buf, count, &output))
 544                 return -EINVAL;
 545
 546         if (output == DCON_OUTPUT_COLOR || output == DCON_OUTPUT_MONO) {
 547                 dcon_set_output(output);
 548                 rc = count;
 549         }
 550
 551         return rc;
 552 }
 553
 554 static ssize_t dcon_freeze_store(struct device *dev,
 555         struct device_attribute *attr, const char *buf, size_t count)
 556 {
 557         int output;
 558
 559         if (_strtoul(buf, count, &output))
 560                 return -EINVAL;
 561
 562         printk("dcon_freeze_store: %d\n", output);
 563
 564         switch (output) {
 565         case 0:
 566                 dcon_set_source(DCON_SOURCE_CPU);
 567                 break;
 568         case 1:
 569                 dcon_set_source_sync(DCON_SOURCE_DCON);
 570                 break;
 571         case 2:  // normally unused
 572                 dcon_set_source(DCON_SOURCE_DCON);
 573                 break;
 574         default:
 575                 return -EINVAL;
 576         }
 577
 578         return count;
 579 }
 580
 581 static ssize_t dcon_resumeline_store(struct device *dev,
 582         struct device_attribute *attr, const char *buf, size_t count)
 583 {
 584         int rl;
 585         int rc = -EINVAL;
 586
 587         if (_strtoul(buf, count, &rl))
 588                 return rc;
 589
 590         resumeline = rl;
 591         dcon_write(DCON_REG_SCAN_INT, resumeline);
 592         rc = count;
 593
 594         return rc;
 595 }
 596
 597 static ssize_t dcon_sleep_store(struct device *dev,
 598         struct device_attribute *attr, const char *buf, size_t count)
 599 {
 600         int output;
 601
 602         if (_strtoul(buf, count, &output))
 603                 return -EINVAL;
 604
 605         dcon_sleep(output ? DCON_SLEEP : DCON_ACTIVE);
 606         return count;
 607 }
 608
 609 static struct device_attribute dcon_device_files[] = {
 610         __ATTR(mode, 0444, dcon_mode_show, NULL),
 611         __ATTR(sleep, 0644, dcon_sleep_show, dcon_sleep_store),
 612         __ATTR(freeze, 0644, dcon_freeze_show, dcon_freeze_store),
 613         __ATTR(output, 0644, dcon_output_show, dcon_output_store),
 614         __ATTR(resumeline, 0644, dcon_resumeline_show, dcon_resumeline_store),
 615 };
 616
 617 static const struct backlight_ops dcon_bl_ops = {
 618         .get_brightness = dconbl_get,
 619         .update_status = dconbl_set
 620 };
 621
 622
 623 static int dcon_reboot_notify(struct notifier_block *nb, unsigned long foo, void *bar)
 624 {
 625         if (dcon_client == NULL)
 626                 return 0;
 627
 628         /* Turn off the DCON. Entirely. */
 629         dcon_write(DCON_REG_MODE, 0x39);
 630         dcon_write(DCON_REG_MODE, 0x32);
 631         return 0;
 632 }
 633
 634 static struct notifier_block dcon_nb = {
 635         .notifier_call = dcon_reboot_notify,
 636         .priority = -1,
 637 };
 638
 639 static int unfreeze_on_panic(struct notifier_block *nb, unsigned long e, void *p)
 640 {
 641         pdata->set_dconload(1);
 642         return NOTIFY_DONE;
 643 }
 644
 645 static struct notifier_block dcon_panic_nb = {
 646         .notifier_call = unfreeze_on_panic,
 647 };
 648
 649 /*
 650  * When the framebuffer sleeps due to external sources (e.g. user idle), power
 651  * down the DCON as well.  Power it back up when the fb comes back to life.
 652  */
 653 static int fb_notifier_callback(struct notifier_block *self, unsigned long event, void *data)
 654 {
 655         struct fb_event *evdata = data;
 656         int *blank = (int *) evdata->data;
 657         if (((event != FB_EVENT_BLANK) && (event != FB_EVENT_CONBLANK)) ||
 658                         ignore_fb_events)
 659                 return 0;
 660         dcon_sleep((*blank) ? DCON_SLEEP : DCON_ACTIVE);
 661         return 0;
 662 }
 663
 664 static struct notifier_block fb_nb = {
 665         .notifier_call = fb_notifier_callback,
 666 };
 667
 668 static int dcon_detect(struct i2c_client *client, struct i2c_board_info *info)
 669 {
 670         strlcpy(info->type, "olpc_dcon", I2C_NAME_SIZE);
 671
 672         return 0;
 673 }
 674
 675 static int dcon_probe(struct i2c_client *client, const struct i2c_device_id *id)
 676 {
 677         int rc, i;
 678
 679         if (num_registered_fb >= 1)
 680                 fbinfo = registered_fb[0];
 681
 682         rc = dcon_hw_init(client, 1);
 683         if (rc)
 684                 goto einit;
 685
 686         /* Add the DCON device */
 687
 688         dcon_device = platform_device_alloc("dcon", -1);
 689
 690         if (dcon_device == NULL) {
 691                 printk("dcon:  Unable to create the DCON device\n");
 692                 rc = -ENOMEM;
 693                 goto eirq;
 694         }
 695         /* Place holder...*/
 696         i2c_set_clientdata(client, dcon_device);
 697
 698         if ((rc = platform_device_add(dcon_device))) {
 699                 printk("dcon:  Unable to add the DCON device\n");
 700                 goto edev;
 701         }
 702
 703         for(i = 0; i < ARRAY_SIZE(dcon_device_files); i++)
 704                 device_create_file(&dcon_device->dev, &dcon_device_files[i]);
 705
 706         /* Add the backlight device for the DCON */
 707
 708         dcon_client = client;
 709
 710         dcon_bl_dev = backlight_device_register("dcon-bl", &dcon_device->dev,
 711                 NULL, &dcon_bl_ops, NULL);
 712
 713         if (IS_ERR(dcon_bl_dev)) {
 714                 printk("Could not register the backlight device for the DCON (%ld)\n", PTR_ERR(dcon_bl_dev));
 715                 dcon_bl_dev = NULL;
 716         }
 717         else {
 718                 dcon_bl_dev->props.max_brightness = 15;
 719                 dcon_bl_dev->props.power = FB_BLANK_UNBLANK;
 720                 dcon_bl_dev->props.brightness = dcon_get_backlight();
 721
 722                 backlight_update_status(dcon_bl_dev);
 723         }
 724
 725         register_reboot_notifier(&dcon_nb);
 726         atomic_notifier_chain_register(&panic_notifier_list, &dcon_panic_nb);
 727         fb_register_client(&fb_nb);
 728
 729         return 0;
 730
 731  edev:
 732         platform_device_unregister(dcon_device);
 733         dcon_device = NULL;
 734  eirq:
 735         free_irq(DCON_IRQ, &dcon_driver);
 736  einit:
 737         return rc;
 738 }
 739
 740 static int dcon_remove(struct i2c_client *client)
 741 {
 742         dcon_client = NULL;
 743
 744         fb_unregister_client(&fb_nb);
 745         unregister_reboot_notifier(&dcon_nb);
 746         atomic_notifier_chain_unregister(&panic_notifier_list, &dcon_panic_nb);
 747
 748         free_irq(DCON_IRQ, &dcon_driver);
 749
 750         if (dcon_bl_dev != NULL)
 751                 backlight_device_unregister(dcon_bl_dev);
 752
 753         if (dcon_device != NULL)
 754                 platform_device_unregister(dcon_device);
 755         cancel_work_sync(&dcon_work);
 756
 757         return 0;
 758 }
 759
 760 #ifdef CONFIG_PM
 761 static int dcon_suspend(struct i2c_client *client, pm_message_t state)
 762 {
 763         if (dcon_sleep_val == DCON_ACTIVE) {
 764                 /* Set up the DCON to have the source */
 765                 dcon_set_source_sync(DCON_SOURCE_DCON);
 766         }
 767
 768         return 0;
 769 }
 770
 771 static int dcon_resume(struct i2c_client *client)
 772 {
 773         if (dcon_sleep_val == DCON_ACTIVE) {
 774                 dcon_bus_stabilize(client, 0);
 775                 dcon_set_source(DCON_SOURCE_CPU);
 776         }
 777
 778         return 0;
 779 }
 780
 781 #endif
 782
 783
 784 static irqreturn_t dcon_interrupt(int irq, void *id)
 785 {
 786         int status = pdata->read_status();
 787
 788         if (status == -1)
 789                 return IRQ_NONE;
 790
 791         switch (status & 3) {
 792         case 3:
 793                 printk(KERN_DEBUG "olpc-dcon: DCONLOAD_MISSED interrupt\n");
 794                 break;
 795
 796         case 2: /* switch to DCON mode */
 797         case 1: /* switch to CPU mode */
 798                 dcon_switched = 1;
 799                 getnstimeofday(&dcon_irq_time);
 800                 wake_up(&dcon_wait_queue);
 801                 break;
 802
 803         case 0:
 804                 /* workaround resume case:  the DCON (on 1.5) doesn't
 805                  * ever assert status 0x01 when switching to CPU mode
 806                  * during resume.  this is because DCONLOAD is de-asserted
 807                  * _immediately_ upon exiting S3, so the actual release
 808                  * of the DCON happened long before this point.
 809                  * see http://dev.laptop.org/ticket/9869
 810                  */
 811                 if (dcon_source != dcon_pending && !dcon_switched) {
 812                         dcon_switched = 1;
 813                         getnstimeofday(&dcon_irq_time);
 814                         wake_up(&dcon_wait_queue);
 815                         printk(KERN_DEBUG "olpc-dcon: switching w/ status 0/0\n");
 816                 } else {
 817                         printk(KERN_DEBUG "olpc-dcon: scanline interrupt w/CPU\n");
 818                 }
 819         }
 820
 821         return IRQ_HANDLED;
 822 }
 823
 824 static struct i2c_device_id dcon_idtable[] = {
 825         { "olpc_dcon",  0 },
 826         { }
 827 };
 828
 829 MODULE_DEVICE_TABLE(i2c, dcon_idtable);
 830
 831 static struct i2c_driver dcon_driver = {
 832         .driver = {
 833                 .name   = "olpc_dcon",
 834         },
 835         .class = I2C_CLASS_DDC | I2C_CLASS_HWMON,
 836         .id_table = dcon_idtable,
 837         .probe = dcon_probe,
 838         .remove = __devexit_p(dcon_remove),
 839         .detect = dcon_detect,
 840         .address_list = normal_i2c,
 841 #ifdef CONFIG_PM
 842         .suspend = dcon_suspend,
 843         .resume = dcon_resume,
 844 #endif
 845 };
 846
 847 #include "olpc_dcon_xo_1.c"
 848
 849 static int __init olpc_dcon_init(void)
 850 {
 851         pdata = &dcon_pdata_xo_1;
 852
 853         i2c_add_driver(&dcon_driver);
 854         return 0;
 855 }
 856
 857 static void __exit olpc_dcon_exit(void)
 858 {
 859         i2c_del_driver(&dcon_driver);
 860 }
 861
 862 module_init(olpc_dcon_init);
 863 module_exit(olpc_dcon_exit);
 864
 865 MODULE_LICENSE("GPL");