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 <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 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                 rc = pdata->init();
 121                 if (rc != 0) {
 122                         printk(KERN_ERR "olpc-dcon:  Unable to init.\n");
 123                         goto err;
 124                 }
 125         }
 126
 127         if (ver < 0xdc02 && !noinit) {
 128                 /* Initialize the DCON registers */
 129
 130                 /* Start with work-arounds for DCON ASIC */
 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, 0x4b, 0x00cc);
 134                 i2c_smbus_write_word_data(client, 0x0b, 0x007a);
 135                 i2c_smbus_write_word_data(client, 0x36, 0x025c);
 136                 i2c_smbus_write_word_data(client, 0x37, 0x025e);
 137
 138                 /* Initialise SDRAM */
 139
 140                 i2c_smbus_write_word_data(client, 0x3b, 0x002b);
 141                 i2c_smbus_write_word_data(client, 0x41, 0x0101);
 142                 i2c_smbus_write_word_data(client, 0x42, 0x0101);
 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                 x = olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0);
 185                 if (x) {
 186                         printk(KERN_WARNING "olpc-dcon:  unable to force dcon "
 187                                         "to power up: %d!\n", x);
 188                         return x;
 189                 }
 190                 msleep(10); /* we'll be conservative */
 191         }
 192
 193         pdata->bus_stabilize_wiggle();
 194
 195         for (x = -1, timeout = 50; timeout && x < 0; timeout--) {
 196                 msleep(1);
 197                 x = dcon_read(DCON_REG_ID);
 198         }
 199         if (x < 0) {
 200                 printk(KERN_ERR "olpc-dcon:  unable to stabilize dcon's "
 201                                 "smbus, reasserting power and praying.\n");
 202                 BUG_ON(olpc_board_at_least(olpc_board(0xc2)));
 203                 x = 0;
 204                 olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0);
 205                 msleep(100);
 206                 is_powered_down = 1;
 207                 goto power_up;  /* argh, stupid hardware.. */
 208         }
 209
 210         if (is_powered_down)
 211                 return dcon_hw_init(client, 0);
 212         return 0;
 213 }
 214
 215 static int dcon_get_backlight(void)
 216 {
 217         if (dcon_client == NULL)
 218                 return 0;
 219
 220         if (bl_val == -1)
 221                 bl_val = dcon_read(DCON_REG_BRIGHT) & 0x0F;
 222
 223         return bl_val;
 224 }
 225
 226
 227 static void dcon_set_backlight_hw(int level)
 228 {
 229         bl_val = level & 0x0F;
 230         dcon_write(DCON_REG_BRIGHT, bl_val);
 231
 232         /* Purposely turn off the backlight when we go to level 0 */
 233         if (bl_val == 0) {
 234                 dcon_disp_mode &= ~MODE_BL_ENABLE;
 235                 dcon_write(DCON_REG_MODE, dcon_disp_mode);
 236         } else if (!(dcon_disp_mode & MODE_BL_ENABLE)) {
 237                 dcon_disp_mode |= MODE_BL_ENABLE;
 238                 dcon_write(DCON_REG_MODE, dcon_disp_mode);
 239         }
 240 }
 241
 242 static void dcon_set_backlight(int level)
 243 {
 244         if (dcon_client == NULL)
 245                 return;
 246
 247         if (bl_val == (level & 0x0F))
 248                 return;
 249
 250         dcon_set_backlight_hw(level);
 251 }
 252
 253 /* Set the output type to either color or mono */
 254
 255 static int dcon_set_output(int arg)
 256 {
 257         if (dcon_output == arg)
 258                 return 0;
 259
 260         dcon_output = arg;
 261
 262         if (arg == DCON_OUTPUT_MONO) {
 263                 dcon_disp_mode &= ~(MODE_CSWIZZLE | MODE_COL_AA);
 264                 dcon_disp_mode |= MODE_MONO_LUMA;
 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                 x = olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0);
 295                 if (x)
 296                         printk(KERN_WARNING "olpc-dcon:  unable to force dcon "
 297                                         "to power down: %d!\n", x);
 298                 else
 299                         dcon_sleep_val = state;
 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                 x = dcon_bus_stabilize(dcon_client, 1);
 305                 if (x)
 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
 356                                "olpc-dcon:  couldn't enable scanline interrupt!\n");
 357                 else {
 358                         /* Wait up to one second for the scanline interrupt */
 359                         wait_event_timeout(dcon_wait_queue,
 360                                            dcon_switched == 1, HZ);
 361                 }
 362
 363                 if (!dcon_switched)
 364                         printk(KERN_ERR "olpc-dcon:  Timeout entering CPU mode; expect a screen glitch.\n");
 365
 366                 /* Turn off the scanline interrupt */
 367                 if (dcon_write(DCON_REG_MODE, dcon_disp_mode))
 368                         printk(KERN_ERR "olpc-dcon:  couldn't disable scanline interrupt!\n");
 369
 370                 /*
 371                  * Ideally we'd like to disable interrupts here so that the
 372                  * fb unblanking and DCON turn on happen at a known time value;
 373                  * however, we can't do that right now with fb_blank
 374                  * messing with semaphores.
 375                  *
 376                  * For now, we just hope..
 377                  */
 378                 console_lock();
 379                 ignore_fb_events = 1;
 380                 if (fb_blank(fbinfo, FB_BLANK_UNBLANK)) {
 381                         ignore_fb_events = 0;
 382                         console_unlock();
 383                         printk(KERN_ERR "olpc-dcon:  Failed to enter CPU mode\n");
 384                         dcon_pending = DCON_SOURCE_DCON;
 385                         return;
 386                 }
 387                 ignore_fb_events = 0;
 388                 console_unlock();
 389
 390                 /* And turn off the DCON */
 391                 pdata->set_dconload(1);
 392                 getnstimeofday(&dcon_load_time);
 393
 394                 printk(KERN_INFO "olpc-dcon: The CPU has control\n");
 395                 break;
 396         case DCON_SOURCE_DCON:
 397         {
 398                 int t;
 399                 struct timespec delta_t;
 400
 401                 printk(KERN_INFO "dcon_source_switch to DCON\n");
 402
 403                 add_wait_queue(&dcon_wait_queue, &wait);
 404                 set_current_state(TASK_UNINTERRUPTIBLE);
 405
 406                 /* Clear DCONLOAD - this implies that the DCON is in control */
 407                 pdata->set_dconload(0);
 408                 getnstimeofday(&dcon_load_time);
 409
 410                 t = schedule_timeout(HZ/2);
 411                 remove_wait_queue(&dcon_wait_queue, &wait);
 412                 set_current_state(TASK_RUNNING);
 413
 414                 if (!dcon_switched) {
 415                         printk(KERN_ERR "olpc-dcon: Timeout entering DCON mode; expect a screen glitch.\n");
 416                 } else {
 417                         /* sometimes the DCON doesn't follow its own rules,
 418                          * and doesn't wait for two vsync pulses before
 419                          * ack'ing the frame load with an IRQ.  the result
 420                          * is that the display shows the *previously*
 421                          * loaded frame.  we can detect this by looking at
 422                          * the time between asserting DCONLOAD and the IRQ --
 423                          * if it's less than 20msec, then the DCON couldn't
 424                          * have seen two VSYNC pulses.  in that case we
 425                          * deassert and reassert, and hope for the best.
 426                          * see http://dev.laptop.org/ticket/9664
 427                          */
 428                         delta_t = timespec_sub(dcon_irq_time, dcon_load_time);
 429                         if (dcon_switched && delta_t.tv_sec == 0 &&
 430                                         delta_t.tv_nsec < NSEC_PER_MSEC * 20) {
 431                                 printk(KERN_ERR "olpc-dcon: missed loading, retrying\n");
 432                                 pdata->set_dconload(1);
 433                                 mdelay(41);
 434                                 pdata->set_dconload(0);
 435                                 getnstimeofday(&dcon_load_time);
 436                                 mdelay(41);
 437                         }
 438                 }
 439
 440                 console_lock();
 441                 ignore_fb_events = 1;
 442                 if (fb_blank(fbinfo, FB_BLANK_POWERDOWN))
 443                         printk(KERN_ERR "olpc-dcon:  couldn't blank fb!\n");
 444                 ignore_fb_events = 0;
 445                 console_unlock();
 446
 447                 printk(KERN_INFO "olpc-dcon: The DCON has control\n");
 448                 break;
 449         }
 450         default:
 451                 BUG();
 452         }
 453
 454         dcon_source = source;
 455 }
 456
 457 static DECLARE_WORK(dcon_work, dcon_source_switch);
 458
 459 static void dcon_set_source(int arg)
 460 {
 461         if (dcon_pending == arg)
 462                 return;
 463
 464         dcon_pending = arg;
 465
 466         if ((dcon_source != arg) && !work_pending(&dcon_work))
 467                 schedule_work(&dcon_work);
 468 }
 469
 470 static void dcon_set_source_sync(int arg)
 471 {
 472         dcon_set_source(arg);
 473         flush_scheduled_work();
 474 }
 475
 476 static int dconbl_set(struct backlight_device *dev)
 477 {
 478
 479         int level = dev->props.brightness;
 480
 481         if (dev->props.power != FB_BLANK_UNBLANK)
 482                 level = 0;
 483
 484         dcon_set_backlight(level);
 485         return 0;
 486 }
 487
 488 static int dconbl_get(struct backlight_device *dev)
 489 {
 490         return dcon_get_backlight();
 491 }
 492
 493 static ssize_t dcon_mode_show(struct device *dev,
 494         struct device_attribute *attr, char *buf)
 495 {
 496         return sprintf(buf, "%4.4X\n", dcon_disp_mode);
 497 }
 498
 499 static ssize_t dcon_sleep_show(struct device *dev,
 500         struct device_attribute *attr, char *buf)
 501 {
 502
 503         return sprintf(buf, "%d\n", dcon_sleep_val);
 504 }
 505
 506 static ssize_t dcon_freeze_show(struct device *dev,
 507         struct device_attribute *attr, char *buf)
 508 {
 509         return sprintf(buf, "%d\n", dcon_source == DCON_SOURCE_DCON ? 1 : 0);
 510 }
 511
 512 static ssize_t dcon_output_show(struct device *dev,
 513         struct device_attribute *attr, char *buf)
 514 {
 515         return sprintf(buf, "%d\n", dcon_output);
 516 }
 517
 518 static ssize_t dcon_resumeline_show(struct device *dev,
 519         struct device_attribute *attr, char *buf)
 520 {
 521         return sprintf(buf, "%d\n", resumeline);
 522 }
 523
 524 static int _strtoul(const char *buf, int len, unsigned int *val)
 525 {
 526
 527         char *endp;
 528         unsigned int output = simple_strtoul(buf, &endp, 0);
 529         int size = endp - buf;
 530
 531         if (*endp && isspace(*endp))
 532                 size++;
 533
 534         if (size != len)
 535                 return -EINVAL;
 536
 537         *val = output;
 538         return 0;
 539 }
 540
 541 static ssize_t dcon_output_store(struct device *dev,
 542         struct device_attribute *attr, const char *buf, size_t count)
 543 {
 544         int output;
 545         int rc = -EINVAL;
 546
 547         if (_strtoul(buf, count, &output))
 548                 return -EINVAL;
 549
 550         if (output == DCON_OUTPUT_COLOR || output == DCON_OUTPUT_MONO) {
 551                 dcon_set_output(output);
 552                 rc = count;
 553         }
 554
 555         return rc;
 556 }
 557
 558 static ssize_t dcon_freeze_store(struct device *dev,
 559         struct device_attribute *attr, const char *buf, size_t count)
 560 {
 561         int output;
 562
 563         if (_strtoul(buf, count, &output))
 564                 return -EINVAL;
 565
 566         printk(KERN_INFO "dcon_freeze_store: %d\n", output);
 567
 568         switch (output) {
 569         case 0:
 570                 dcon_set_source(DCON_SOURCE_CPU);
 571                 break;
 572         case 1:
 573                 dcon_set_source_sync(DCON_SOURCE_DCON);
 574                 break;
 575         case 2:  /* normally unused */
 576                 dcon_set_source(DCON_SOURCE_DCON);
 577                 break;
 578         default:
 579                 return -EINVAL;
 580         }
 581
 582         return count;
 583 }
 584
 585 static ssize_t dcon_resumeline_store(struct device *dev,
 586         struct device_attribute *attr, const char *buf, size_t count)
 587 {
 588         int rl;
 589         int rc = -EINVAL;
 590
 591         if (_strtoul(buf, count, &rl))
 592                 return rc;
 593
 594         resumeline = rl;
 595         dcon_write(DCON_REG_SCAN_INT, resumeline);
 596         rc = count;
 597
 598         return rc;
 599 }
 600
 601 static ssize_t dcon_sleep_store(struct device *dev,
 602         struct device_attribute *attr, const char *buf, size_t count)
 603 {
 604         int output;
 605
 606         if (_strtoul(buf, count, &output))
 607                 return -EINVAL;
 608
 609         dcon_sleep(output ? DCON_SLEEP : DCON_ACTIVE);
 610         return count;
 611 }
 612
 613 static struct device_attribute dcon_device_files[] = {
 614         __ATTR(mode, 0444, dcon_mode_show, NULL),
 615         __ATTR(sleep, 0644, dcon_sleep_show, dcon_sleep_store),
 616         __ATTR(freeze, 0644, dcon_freeze_show, dcon_freeze_store),
 617         __ATTR(output, 0644, dcon_output_show, dcon_output_store),
 618         __ATTR(resumeline, 0644, dcon_resumeline_show, dcon_resumeline_store),
 619 };
 620
 621 static const struct backlight_ops dcon_bl_ops = {
 622         .get_brightness = dconbl_get,
 623         .update_status = dconbl_set
 624 };
 625
 626
 627 static int dcon_reboot_notify(struct notifier_block *nb,
 628                               unsigned long foo, void *bar)
 629 {
 630         if (dcon_client == NULL)
 631                 return 0;
 632
 633         /* Turn off the DCON. Entirely. */
 634         dcon_write(DCON_REG_MODE, 0x39);
 635         dcon_write(DCON_REG_MODE, 0x32);
 636         return 0;
 637 }
 638
 639 static struct notifier_block dcon_nb = {
 640         .notifier_call = dcon_reboot_notify,
 641         .priority = -1,
 642 };
 643
 644 static int unfreeze_on_panic(struct notifier_block *nb,
 645                              unsigned long e, void *p)
 646 {
 647         pdata->set_dconload(1);
 648         return NOTIFY_DONE;
 649 }
 650
 651 static struct notifier_block dcon_panic_nb = {
 652         .notifier_call = unfreeze_on_panic,
 653 };
 654
 655 /*
 656  * When the framebuffer sleeps due to external sources (e.g. user idle), power
 657  * down the DCON as well.  Power it back up when the fb comes back to life.
 658  */
 659 static int fb_notifier_callback(struct notifier_block *self,
 660                                 unsigned long event, void *data)
 661 {
 662         struct fb_event *evdata = data;
 663         int *blank = (int *) evdata->data;
 664         if (((event != FB_EVENT_BLANK) && (event != FB_EVENT_CONBLANK)) ||
 665                         ignore_fb_events)
 666                 return 0;
 667         dcon_sleep((*blank) ? DCON_SLEEP : DCON_ACTIVE);
 668         return 0;
 669 }
 670
 671 static struct notifier_block fb_nb = {
 672         .notifier_call = fb_notifier_callback,
 673 };
 674
 675 static int dcon_detect(struct i2c_client *client, struct i2c_board_info *info)
 676 {
 677         strlcpy(info->type, "olpc_dcon", I2C_NAME_SIZE);
 678
 679         return 0;
 680 }
 681
 682 static int dcon_probe(struct i2c_client *client, const struct i2c_device_id *id)
 683 {
 684         int rc, i, j;
 685
 686         if (num_registered_fb >= 1)
 687                 fbinfo = registered_fb[0];
 688
 689         rc = dcon_hw_init(client, 1);
 690         if (rc)
 691                 goto einit;
 692
 693         /* Add the DCON device */
 694
 695         dcon_device = platform_device_alloc("dcon", -1);
 696
 697         if (dcon_device == NULL) {
 698                 printk(KERN_ERR "dcon:  Unable to create the DCON device\n");
 699                 rc = -ENOMEM;
 700                 goto eirq;
 701         }
 702         /* Place holder...*/
 703         i2c_set_clientdata(client, dcon_device);
 704         rc = platform_device_add(dcon_device);
 705
 706         if (rc) {
 707                 printk(KERN_ERR "dcon:  Unable to add the DCON device\n");
 708                 goto edev;
 709         }
 710
 711         for (i = 0; i < ARRAY_SIZE(dcon_device_files); i++) {
 712                 rc = device_create_file(&dcon_device->dev,
 713                                         &dcon_device_files[i]);
 714                 if (rc) {
 715                         dev_err(&dcon_device->dev, "Cannot create sysfs file\n");
 716                         goto ecreate;
 717                 }
 718         }
 719
 720         /* Add the backlight device for the DCON */
 721
 722         dcon_client = client;
 723
 724         dcon_bl_dev = backlight_device_register("dcon-bl", &dcon_device->dev,
 725                 NULL, &dcon_bl_ops, NULL);
 726
 727         if (IS_ERR(dcon_bl_dev)) {
 728                 printk(KERN_ERR "Cannot register the backlight device (%ld)\n",
 729                        PTR_ERR(dcon_bl_dev));
 730                 dcon_bl_dev = NULL;
 731         } else {
 732                 dcon_bl_dev->props.max_brightness = 15;
 733                 dcon_bl_dev->props.power = FB_BLANK_UNBLANK;
 734                 dcon_bl_dev->props.brightness = dcon_get_backlight();
 735
 736                 backlight_update_status(dcon_bl_dev);
 737         }
 738
 739         register_reboot_notifier(&dcon_nb);
 740         atomic_notifier_chain_register(&panic_notifier_list, &dcon_panic_nb);
 741         fb_register_client(&fb_nb);
 742
 743         return 0;
 744
 745  ecreate:
 746         for (j = 0; j < i; j++)
 747                 device_remove_file(&dcon_device->dev, &dcon_device_files[j]);
 748  edev:
 749         platform_device_unregister(dcon_device);
 750         dcon_device = NULL;
 751  eirq:
 752         free_irq(DCON_IRQ, &dcon_driver);
 753  einit:
 754         return rc;
 755 }
 756
 757 static int dcon_remove(struct i2c_client *client)
 758 {
 759         dcon_client = NULL;
 760
 761         fb_unregister_client(&fb_nb);
 762         unregister_reboot_notifier(&dcon_nb);
 763         atomic_notifier_chain_unregister(&panic_notifier_list, &dcon_panic_nb);
 764
 765         free_irq(DCON_IRQ, &dcon_driver);
 766
 767         if (dcon_bl_dev != NULL)
 768                 backlight_device_unregister(dcon_bl_dev);
 769
 770         if (dcon_device != NULL)
 771                 platform_device_unregister(dcon_device);
 772         cancel_work_sync(&dcon_work);
 773
 774         return 0;
 775 }
 776
 777 #ifdef CONFIG_PM
 778 static int dcon_suspend(struct i2c_client *client, pm_message_t state)
 779 {
 780         if (dcon_sleep_val == DCON_ACTIVE) {
 781                 /* Set up the DCON to have the source */
 782                 dcon_set_source_sync(DCON_SOURCE_DCON);
 783         }
 784
 785         return 0;
 786 }
 787
 788 static int dcon_resume(struct i2c_client *client)
 789 {
 790         if (dcon_sleep_val == DCON_ACTIVE) {
 791                 dcon_bus_stabilize(client, 0);
 792                 dcon_set_source(DCON_SOURCE_CPU);
 793         }
 794
 795         return 0;
 796 }
 797
 798 #endif
 799
 800
 801 static irqreturn_t dcon_interrupt(int irq, void *id)
 802 {
 803         int status = pdata->read_status();
 804
 805         if (status == -1)
 806                 return IRQ_NONE;
 807
 808         switch (status & 3) {
 809         case 3:
 810                 printk(KERN_DEBUG "olpc-dcon: DCONLOAD_MISSED interrupt\n");
 811                 break;
 812
 813         case 2: /* switch to DCON mode */
 814         case 1: /* switch to CPU mode */
 815                 dcon_switched = 1;
 816                 getnstimeofday(&dcon_irq_time);
 817                 wake_up(&dcon_wait_queue);
 818                 break;
 819
 820         case 0:
 821                 /* workaround resume case:  the DCON (on 1.5) doesn't
 822                  * ever assert status 0x01 when switching to CPU mode
 823                  * during resume.  this is because DCONLOAD is de-asserted
 824                  * _immediately_ upon exiting S3, so the actual release
 825                  * of the DCON happened long before this point.
 826                  * see http://dev.laptop.org/ticket/9869
 827                  */
 828                 if (dcon_source != dcon_pending && !dcon_switched) {
 829                         dcon_switched = 1;
 830                         getnstimeofday(&dcon_irq_time);
 831                         wake_up(&dcon_wait_queue);
 832                         printk(KERN_DEBUG "olpc-dcon: switching w/ status 0/0\n");
 833                 } else {
 834                         printk(KERN_DEBUG "olpc-dcon: scanline interrupt w/CPU\n");
 835                 }
 836         }
 837
 838         return IRQ_HANDLED;
 839 }
 840
 841 static struct i2c_device_id dcon_idtable[] = {
 842         { "olpc_dcon",  0 },
 843         { }
 844 };
 845
 846 MODULE_DEVICE_TABLE(i2c, dcon_idtable);
 847
 848 static struct i2c_driver dcon_driver = {
 849         .driver = {
 850                 .name   = "olpc_dcon",
 851         },
 852         .class = I2C_CLASS_DDC | I2C_CLASS_HWMON,
 853         .id_table = dcon_idtable,
 854         .probe = dcon_probe,
 855         .remove = __devexit_p(dcon_remove),
 856         .detect = dcon_detect,
 857         .address_list = normal_i2c,
 858 #ifdef CONFIG_PM
 859         .suspend = dcon_suspend,
 860         .resume = dcon_resume,
 861 #endif
 862 };
 863
 864 #include "olpc_dcon_xo_1.c"
 865
 866 static int __init olpc_dcon_init(void)
 867 {
 868         pdata = &dcon_pdata_xo_1;
 869
 870         i2c_add_driver(&dcon_driver);
 871         return 0;
 872 }
 873
 874 static void __exit olpc_dcon_exit(void)
 875 {
 876         i2c_del_driver(&dcon_driver);
 877 }
 878
 879 module_init(olpc_dcon_init);
 880 module_exit(olpc_dcon_exit);
 881
 882 MODULE_LICENSE("GPL");