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/backlight.h>
  25 #include <linux/device.h>
  26 #include <linux/uaccess.h>
  27 #include <linux/ctype.h>
  28 #include <linux/reboot.h>
  29 #include <asm/tsc.h>
  30 #include <asm/olpc.h>
  31
  32 #include "olpc_dcon.h"
  33
  34 /* Module definitions */
  35
  36 static int resumeline = 898;
  37 module_param(resumeline, int, 0444);
  38
  39 static int noinit;
  40 module_param(noinit, int, 0444);
  41
  42 /* Default off since it doesn't work on DCON ASIC in B-test OLPC board */
  43 static int useaa = 1;
  44 module_param(useaa, int, 0444);
  45
  46 static struct dcon_platform_data *pdata;
  47
  48 /* I2C structures */
  49
  50 /* Platform devices */
  51 static struct platform_device *dcon_device;
  52
  53 /* Backlight device */
  54 static struct backlight_device *dcon_bl_dev;
  55
  56 /* Variables used during switches */
  57 static int dcon_switched;
  58 static struct timespec dcon_irq_time;
  59 static struct timespec dcon_load_time;
  60
  61 static DECLARE_WAIT_QUEUE_HEAD(dcon_wait_queue);
  62
  63 static unsigned short normal_i2c[] = { 0x0d, I2C_CLIENT_END };
  64
  65 static s32 dcon_write(struct dcon_priv *dcon, u8 reg, u16 val)
  66 {
  67         return i2c_smbus_write_word_data(dcon->client, reg, val);
  68 }
  69
  70 static s32 dcon_read(struct dcon_priv *dcon, u8 reg)
  71 {
  72         return i2c_smbus_read_word_data(dcon->client, reg);
  73 }
  74
  75 /* The current backlight value - this saves us some smbus traffic */
  76 static int bl_val = -1;
  77
  78 /* ===== API functions - these are called by a variety of users ==== */
  79
  80 static int dcon_hw_init(struct dcon_priv *dcon, int is_init)
  81 {
  82         struct i2c_client *client = dcon->client;
  83         uint16_t ver;
  84         int rc = 0;
  85
  86         ver = i2c_smbus_read_word_data(client, DCON_REG_ID);
  87         if ((ver >> 8) != 0xDC) {
  88                 printk(KERN_ERR "olpc-dcon:  DCON ID not 0xDCxx: 0x%04x "
  89                                 "instead.\n", ver);
  90                 rc = -ENXIO;
  91                 goto err;
  92         }
  93
  94         if (is_init) {
  95                 printk(KERN_INFO "olpc-dcon:  Discovered DCON version %x\n",
  96                                 ver & 0xFF);
  97                 rc = pdata->init(dcon);
  98                 if (rc != 0) {
  99                         printk(KERN_ERR "olpc-dcon:  Unable to init.\n");
 100                         goto err;
 101                 }
 102         }
 103
 104         if (ver < 0xdc02 && !noinit) {
 105                 /* Initialize the DCON registers */
 106
 107                 /* Start with work-arounds for DCON ASIC */
 108                 i2c_smbus_write_word_data(client, 0x4b, 0x00cc);
 109                 i2c_smbus_write_word_data(client, 0x4b, 0x00cc);
 110                 i2c_smbus_write_word_data(client, 0x4b, 0x00cc);
 111                 i2c_smbus_write_word_data(client, 0x0b, 0x007a);
 112                 i2c_smbus_write_word_data(client, 0x36, 0x025c);
 113                 i2c_smbus_write_word_data(client, 0x37, 0x025e);
 114
 115                 /* Initialise SDRAM */
 116
 117                 i2c_smbus_write_word_data(client, 0x3b, 0x002b);
 118                 i2c_smbus_write_word_data(client, 0x41, 0x0101);
 119                 i2c_smbus_write_word_data(client, 0x42, 0x0101);
 120         } else if (!noinit) {
 121                 /* SDRAM setup/hold time */
 122                 i2c_smbus_write_word_data(client, 0x3a, 0xc040);
 123                 i2c_smbus_write_word_data(client, 0x41, 0x0000);
 124                 i2c_smbus_write_word_data(client, 0x41, 0x0101);
 125                 i2c_smbus_write_word_data(client, 0x42, 0x0101);
 126         }
 127
 128         /* Colour swizzle, AA, no passthrough, backlight */
 129         if (is_init) {
 130                 dcon->disp_mode = MODE_PASSTHRU | MODE_BL_ENABLE |
 131                                 MODE_CSWIZZLE;
 132                 if (useaa)
 133                         dcon->disp_mode |= MODE_COL_AA;
 134         }
 135         i2c_smbus_write_word_data(client, DCON_REG_MODE, dcon->disp_mode);
 136
 137
 138         /* Set the scanline to interrupt on during resume */
 139         i2c_smbus_write_word_data(client, DCON_REG_SCAN_INT, resumeline);
 140
 141 err:
 142         return rc;
 143 }
 144
 145 /*
 146  * The smbus doesn't always come back due to what is believed to be
 147  * hardware (power rail) bugs.  For older models where this is known to
 148  * occur, our solution is to attempt to wait for the bus to stabilize;
 149  * if it doesn't happen, cut power to the dcon, repower it, and wait
 150  * for the bus to stabilize.  Rinse, repeat until we have a working
 151  * smbus.  For newer models, we simply BUG(); we want to know if this
 152  * still happens despite the power fixes that have been made!
 153  */
 154 static int dcon_bus_stabilize(struct dcon_priv *dcon, int is_powered_down)
 155 {
 156         unsigned long timeout;
 157         int x;
 158
 159 power_up:
 160         if (is_powered_down) {
 161                 x = 1;
 162                 x = olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0);
 163                 if (x) {
 164                         printk(KERN_WARNING "olpc-dcon:  unable to force dcon "
 165                                         "to power up: %d!\n", x);
 166                         return x;
 167                 }
 168                 msleep(10); /* we'll be conservative */
 169         }
 170
 171         pdata->bus_stabilize_wiggle();
 172
 173         for (x = -1, timeout = 50; timeout && x < 0; timeout--) {
 174                 msleep(1);
 175                 x = dcon_read(dcon, DCON_REG_ID);
 176         }
 177         if (x < 0) {
 178                 printk(KERN_ERR "olpc-dcon:  unable to stabilize dcon's "
 179                                 "smbus, reasserting power and praying.\n");
 180                 BUG_ON(olpc_board_at_least(olpc_board(0xc2)));
 181                 x = 0;
 182                 olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0);
 183                 msleep(100);
 184                 is_powered_down = 1;
 185                 goto power_up;  /* argh, stupid hardware.. */
 186         }
 187
 188         if (is_powered_down)
 189                 return dcon_hw_init(dcon, 0);
 190         return 0;
 191 }
 192
 193 static int dcon_get_backlight(struct dcon_priv *dcon)
 194 {
 195         if (!dcon || !dcon->client)
 196                 return 0;
 197
 198         if (bl_val == -1)
 199                 bl_val = dcon_read(dcon, DCON_REG_BRIGHT) & 0x0F;
 200
 201         return bl_val;
 202 }
 203
 204
 205 static void dcon_set_backlight_hw(struct dcon_priv *dcon, int level)
 206 {
 207         bl_val = level & 0x0F;
 208         dcon_write(dcon, DCON_REG_BRIGHT, bl_val);
 209
 210         /* Purposely turn off the backlight when we go to level 0 */
 211         if (bl_val == 0) {
 212                 dcon->disp_mode &= ~MODE_BL_ENABLE;
 213                 dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
 214         } else if (!(dcon->disp_mode & MODE_BL_ENABLE)) {
 215                 dcon->disp_mode |= MODE_BL_ENABLE;
 216                 dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
 217         }
 218 }
 219
 220 static void dcon_set_backlight(struct dcon_priv *dcon, int level)
 221 {
 222         if (!dcon || !dcon->client)
 223                 return;
 224
 225         if (bl_val == (level & 0x0F))
 226                 return;
 227
 228         dcon_set_backlight_hw(dcon, level);
 229 }
 230
 231 /* Set the output type to either color or mono */
 232 static int dcon_set_mono_mode(struct dcon_priv *dcon, bool enable_mono)
 233 {
 234         if (dcon->mono == enable_mono)
 235                 return 0;
 236
 237         dcon->mono = enable_mono;
 238
 239         if (enable_mono) {
 240                 dcon->disp_mode &= ~(MODE_CSWIZZLE | MODE_COL_AA);
 241                 dcon->disp_mode |= MODE_MONO_LUMA;
 242         } else {
 243                 dcon->disp_mode &= ~(MODE_MONO_LUMA);
 244                 dcon->disp_mode |= MODE_CSWIZZLE;
 245                 if (useaa)
 246                         dcon->disp_mode |= MODE_COL_AA;
 247         }
 248
 249         dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
 250         return 0;
 251 }
 252
 253 /* For now, this will be really stupid - we need to address how
 254  * DCONLOAD works in a sleep and account for it accordingly
 255  */
 256
 257 static void dcon_sleep(struct dcon_priv *dcon, bool sleep)
 258 {
 259         int x;
 260
 261         /* Turn off the backlight and put the DCON to sleep */
 262
 263         if (dcon->asleep == sleep)
 264                 return;
 265
 266         if (!olpc_board_at_least(olpc_board(0xc2)))
 267                 return;
 268
 269         if (sleep) {
 270                 x = 0;
 271                 x = olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0);
 272                 if (x)
 273                         printk(KERN_WARNING "olpc-dcon:  unable to force dcon "
 274                                         "to power down: %d!\n", x);
 275                 else
 276                         dcon->asleep = sleep;
 277         } else {
 278                 /* Only re-enable the backlight if the backlight value is set */
 279                 if (bl_val != 0)
 280                         dcon->disp_mode |= MODE_BL_ENABLE;
 281                 x = dcon_bus_stabilize(dcon, 1);
 282                 if (x)
 283                         printk(KERN_WARNING "olpc-dcon:  unable to reinit dcon"
 284                                         " hardware: %d!\n", x);
 285                 else
 286                         dcon->asleep = sleep;
 287
 288                 /* Restore backlight */
 289                 dcon_set_backlight_hw(dcon, bl_val);
 290         }
 291
 292         /* We should turn off some stuff in the framebuffer - but what? */
 293 }
 294
 295 /* the DCON seems to get confused if we change DCONLOAD too
 296  * frequently -- i.e., approximately faster than frame time.
 297  * normally we don't change it this fast, so in general we won't
 298  * delay here.
 299  */
 300 void dcon_load_holdoff(void)
 301 {
 302         struct timespec delta_t, now;
 303         while (1) {
 304                 getnstimeofday(&now);
 305                 delta_t = timespec_sub(now, dcon_load_time);
 306                 if (delta_t.tv_sec != 0 ||
 307                         delta_t.tv_nsec > NSEC_PER_MSEC * 20) {
 308                         break;
 309                 }
 310                 mdelay(4);
 311         }
 312 }
 313
 314 static bool dcon_blank_fb(struct dcon_priv *dcon, bool blank)
 315 {
 316         int err;
 317
 318         if (!lock_fb_info(dcon->fbinfo)) {
 319                 dev_err(&dcon->client->dev, "unable to lock framebuffer\n");
 320                 return false;
 321         }
 322         console_lock();
 323         dcon->ignore_fb_events = true;
 324         err = fb_blank(dcon->fbinfo,
 325                         blank ? FB_BLANK_POWERDOWN : FB_BLANK_UNBLANK);
 326         dcon->ignore_fb_events = false;
 327         console_unlock();
 328         unlock_fb_info(dcon->fbinfo);
 329
 330         if (err) {
 331                 dev_err(&dcon->client->dev, "couldn't %sblank framebuffer\n",
 332                                 blank ? "" : "un");
 333                 return false;
 334         }
 335         return true;
 336 }
 337
 338 /* Set the source of the display (CPU or DCON) */
 339 static void dcon_source_switch(struct work_struct *work)
 340 {
 341         struct dcon_priv *dcon = container_of(work, struct dcon_priv,
 342                         switch_source);
 343         DECLARE_WAITQUEUE(wait, current);
 344         int source = dcon->pending_src;
 345
 346         if (dcon->curr_src == source)
 347                 return;
 348
 349         dcon_load_holdoff();
 350
 351         dcon_switched = 0;
 352
 353         switch (source) {
 354         case DCON_SOURCE_CPU:
 355                 printk("dcon_source_switch to CPU\n");
 356                 /* Enable the scanline interrupt bit */
 357                 if (dcon_write(dcon, DCON_REG_MODE,
 358                                 dcon->disp_mode | MODE_SCAN_INT))
 359                         printk(KERN_ERR
 360                                "olpc-dcon:  couldn't enable scanline interrupt!\n");
 361                 else {
 362                         /* Wait up to one second for the scanline interrupt */
 363                         wait_event_timeout(dcon_wait_queue,
 364                                            dcon_switched == 1, HZ);
 365                 }
 366
 367                 if (!dcon_switched)
 368                         printk(KERN_ERR "olpc-dcon:  Timeout entering CPU mode; expect a screen glitch.\n");
 369
 370                 /* Turn off the scanline interrupt */
 371                 if (dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode))
 372                         printk(KERN_ERR "olpc-dcon:  couldn't disable scanline interrupt!\n");
 373
 374                 /*
 375                  * Ideally we'd like to disable interrupts here so that the
 376                  * fb unblanking and DCON turn on happen at a known time value;
 377                  * however, we can't do that right now with fb_blank
 378                  * messing with semaphores.
 379                  *
 380                  * For now, we just hope..
 381                  */
 382                 if (!dcon_blank_fb(dcon, false)) {
 383                         printk(KERN_ERR "olpc-dcon:  Failed to enter CPU mode\n");
 384                         dcon->pending_src = DCON_SOURCE_DCON;
 385                         return;
 386                 }
 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(KERN_INFO "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                 dcon_blank_fb(dcon, true);
 439                 printk(KERN_INFO "olpc-dcon: The DCON has control\n");
 440                 break;
 441         }
 442         default:
 443                 BUG();
 444         }
 445
 446         dcon->curr_src = source;
 447 }
 448
 449 static void dcon_set_source(struct dcon_priv *dcon, int arg)
 450 {
 451         if (dcon->pending_src == arg)
 452                 return;
 453
 454         dcon->pending_src = arg;
 455
 456         if ((dcon->curr_src != arg) && !work_pending(&dcon->switch_source))
 457                 schedule_work(&dcon->switch_source);
 458 }
 459
 460 static void dcon_set_source_sync(struct dcon_priv *dcon, int arg)
 461 {
 462         dcon_set_source(dcon, arg);
 463         flush_scheduled_work();
 464 }
 465
 466 static int dconbl_set(struct backlight_device *dev)
 467 {
 468         struct dcon_priv *dcon = bl_get_data(dev);
 469         int level = dev->props.brightness;
 470
 471         if (dev->props.power != FB_BLANK_UNBLANK)
 472                 level = 0;
 473
 474         dcon_set_backlight(dcon, level);
 475         return 0;
 476 }
 477
 478 static int dconbl_get(struct backlight_device *dev)
 479 {
 480         struct dcon_priv *dcon = bl_get_data(dev);
 481         return dcon_get_backlight(dcon);
 482 }
 483
 484 static ssize_t dcon_mode_show(struct device *dev,
 485         struct device_attribute *attr, char *buf)
 486 {
 487         struct dcon_priv *dcon = dev_get_drvdata(dev);
 488         return sprintf(buf, "%4.4X\n", dcon->disp_mode);
 489 }
 490
 491 static ssize_t dcon_sleep_show(struct device *dev,
 492         struct device_attribute *attr, char *buf)
 493 {
 494
 495         struct dcon_priv *dcon = dev_get_drvdata(dev);
 496         return sprintf(buf, "%d\n", dcon->asleep);
 497 }
 498
 499 static ssize_t dcon_freeze_show(struct device *dev,
 500         struct device_attribute *attr, char *buf)
 501 {
 502         struct dcon_priv *dcon = dev_get_drvdata(dev);
 503         return sprintf(buf, "%d\n", dcon->curr_src == DCON_SOURCE_DCON ? 1 : 0);
 504 }
 505
 506 static ssize_t dcon_mono_show(struct device *dev,
 507         struct device_attribute *attr, char *buf)
 508 {
 509         struct dcon_priv *dcon = dev_get_drvdata(dev);
 510         return sprintf(buf, "%d\n", dcon->mono);
 511 }
 512
 513 static ssize_t dcon_resumeline_show(struct device *dev,
 514         struct device_attribute *attr, char *buf)
 515 {
 516         return sprintf(buf, "%d\n", resumeline);
 517 }
 518
 519 static ssize_t dcon_mono_store(struct device *dev,
 520         struct device_attribute *attr, const char *buf, size_t count)
 521 {
 522         unsigned long enable_mono;
 523         int rc;
 524
 525         rc = strict_strtoul(buf, 10, &enable_mono);
 526         if (rc)
 527                 return rc;
 528
 529         dcon_set_mono_mode(dev_get_drvdata(dev), enable_mono ? true : false);
 530
 531         return count;
 532 }
 533
 534 static ssize_t dcon_freeze_store(struct device *dev,
 535         struct device_attribute *attr, const char *buf, size_t count)
 536 {
 537         struct dcon_priv *dcon = dev_get_drvdata(dev);
 538         unsigned long output;
 539         int ret;
 540
 541         ret = strict_strtoul(buf, 10, &output);
 542         if (ret)
 543                 return ret;
 544
 545         printk(KERN_INFO "dcon_freeze_store: %lu\n", output);
 546
 547         switch (output) {
 548         case 0:
 549                 dcon_set_source(dcon, DCON_SOURCE_CPU);
 550                 break;
 551         case 1:
 552                 dcon_set_source_sync(dcon, DCON_SOURCE_DCON);
 553                 break;
 554         case 2:  /* normally unused */
 555                 dcon_set_source(dcon, DCON_SOURCE_DCON);
 556                 break;
 557         default:
 558                 return -EINVAL;
 559         }
 560
 561         return count;
 562 }
 563
 564 static ssize_t dcon_resumeline_store(struct device *dev,
 565         struct device_attribute *attr, const char *buf, size_t count)
 566 {
 567         unsigned long rl;
 568         int rc;
 569
 570         rc = strict_strtoul(buf, 10, &rl);
 571         if (rc)
 572                 return rc;
 573
 574         resumeline = rl;
 575         dcon_write(dev_get_drvdata(dev), DCON_REG_SCAN_INT, resumeline);
 576
 577         return count;
 578 }
 579
 580 static ssize_t dcon_sleep_store(struct device *dev,
 581         struct device_attribute *attr, const char *buf, size_t count)
 582 {
 583         unsigned long output;
 584         int ret;
 585
 586         ret = strict_strtoul(buf, 10, &output);
 587         if (ret)
 588                 return ret;
 589
 590         dcon_sleep(dev_get_drvdata(dev), output ? true : false);
 591         return count;
 592 }
 593
 594 static struct device_attribute dcon_device_files[] = {
 595         __ATTR(mode, 0444, dcon_mode_show, NULL),
 596         __ATTR(sleep, 0644, dcon_sleep_show, dcon_sleep_store),
 597         __ATTR(freeze, 0644, dcon_freeze_show, dcon_freeze_store),
 598         __ATTR(monochrome, 0644, dcon_mono_show, dcon_mono_store),
 599         __ATTR(resumeline, 0644, dcon_resumeline_show, dcon_resumeline_store),
 600 };
 601
 602 static const struct backlight_ops dcon_bl_ops = {
 603         .get_brightness = dconbl_get,
 604         .update_status = dconbl_set
 605 };
 606
 607
 608 static int dcon_reboot_notify(struct notifier_block *nb,
 609                               unsigned long foo, void *bar)
 610 {
 611         struct dcon_priv *dcon = container_of(nb, struct dcon_priv, reboot_nb);
 612
 613         if (!dcon || !dcon->client)
 614                 return 0;
 615
 616         /* Turn off the DCON. Entirely. */
 617         dcon_write(dcon, DCON_REG_MODE, 0x39);
 618         dcon_write(dcon, DCON_REG_MODE, 0x32);
 619         return 0;
 620 }
 621
 622 static int unfreeze_on_panic(struct notifier_block *nb,
 623                              unsigned long e, void *p)
 624 {
 625         pdata->set_dconload(1);
 626         return NOTIFY_DONE;
 627 }
 628
 629 static struct notifier_block dcon_panic_nb = {
 630         .notifier_call = unfreeze_on_panic,
 631 };
 632
 633 /*
 634  * When the framebuffer sleeps due to external sources (e.g. user idle), power
 635  * down the DCON as well.  Power it back up when the fb comes back to life.
 636  */
 637 static int dcon_fb_notifier(struct notifier_block *self,
 638                                 unsigned long event, void *data)
 639 {
 640         struct fb_event *evdata = data;
 641         struct dcon_priv *dcon = container_of(self, struct dcon_priv,
 642                         fbevent_nb);
 643         int *blank = (int *) evdata->data;
 644         if (((event != FB_EVENT_BLANK) && (event != FB_EVENT_CONBLANK)) ||
 645                         dcon->ignore_fb_events)
 646                 return 0;
 647         dcon_sleep(dcon, *blank ? true : false);
 648         return 0;
 649 }
 650
 651 static int dcon_detect(struct i2c_client *client, struct i2c_board_info *info)
 652 {
 653         strlcpy(info->type, "olpc_dcon", I2C_NAME_SIZE);
 654
 655         return 0;
 656 }
 657
 658 static int dcon_probe(struct i2c_client *client, const struct i2c_device_id *id)
 659 {
 660         struct dcon_priv *dcon;
 661         int rc, i, j;
 662
 663         if (!pdata)
 664                 return -ENXIO;
 665
 666         dcon = kzalloc(sizeof(*dcon), GFP_KERNEL);
 667         if (!dcon)
 668                 return -ENOMEM;
 669
 670         dcon->client = client;
 671         INIT_WORK(&dcon->switch_source, dcon_source_switch);
 672         dcon->reboot_nb.notifier_call = dcon_reboot_notify;
 673         dcon->reboot_nb.priority = -1;
 674         dcon->fbevent_nb.notifier_call = dcon_fb_notifier;
 675
 676         i2c_set_clientdata(client, dcon);
 677
 678         if (num_registered_fb < 1) {
 679                 dev_err(&client->dev, "DCON driver requires a registered fb\n");
 680                 rc = -EIO;
 681                 goto einit;
 682         }
 683         dcon->fbinfo = registered_fb[0];
 684
 685         rc = dcon_hw_init(dcon, 1);
 686         if (rc)
 687                 goto einit;
 688
 689         /* Add the DCON device */
 690
 691         dcon_device = platform_device_alloc("dcon", -1);
 692
 693         if (dcon_device == NULL) {
 694                 printk(KERN_ERR "dcon:  Unable to create the DCON device\n");
 695                 rc = -ENOMEM;
 696                 goto eirq;
 697         }
 698         rc = platform_device_add(dcon_device);
 699         platform_set_drvdata(dcon_device, dcon);
 700
 701         if (rc) {
 702                 printk(KERN_ERR "dcon:  Unable to add the DCON device\n");
 703                 goto edev;
 704         }
 705
 706         for (i = 0; i < ARRAY_SIZE(dcon_device_files); i++) {
 707                 rc = device_create_file(&dcon_device->dev,
 708                                         &dcon_device_files[i]);
 709                 if (rc) {
 710                         dev_err(&dcon_device->dev, "Cannot create sysfs file\n");
 711                         goto ecreate;
 712                 }
 713         }
 714
 715         /* Add the backlight device for the DCON */
 716         dcon_bl_dev = backlight_device_register("dcon-bl", &dcon_device->dev,
 717                 dcon, &dcon_bl_ops, NULL);
 718
 719         if (IS_ERR(dcon_bl_dev)) {
 720                 printk(KERN_ERR "Cannot register the backlight device (%ld)\n",
 721                        PTR_ERR(dcon_bl_dev));
 722                 dcon_bl_dev = NULL;
 723         } else {
 724                 dcon_bl_dev->props.max_brightness = 15;
 725                 dcon_bl_dev->props.power = FB_BLANK_UNBLANK;
 726                 dcon_bl_dev->props.brightness = dcon_get_backlight(dcon);
 727
 728                 backlight_update_status(dcon_bl_dev);
 729         }
 730
 731         register_reboot_notifier(&dcon->reboot_nb);
 732         atomic_notifier_chain_register(&panic_notifier_list, &dcon_panic_nb);
 733         fb_register_client(&dcon->fbevent_nb);
 734
 735         return 0;
 736
 737  ecreate:
 738         for (j = 0; j < i; j++)
 739                 device_remove_file(&dcon_device->dev, &dcon_device_files[j]);
 740  edev:
 741         platform_device_unregister(dcon_device);
 742         dcon_device = NULL;
 743  eirq:
 744         free_irq(DCON_IRQ, dcon);
 745  einit:
 746         i2c_set_clientdata(client, NULL);
 747         kfree(dcon);
 748         return rc;
 749 }
 750
 751 static int dcon_remove(struct i2c_client *client)
 752 {
 753         struct dcon_priv *dcon = i2c_get_clientdata(client);
 754
 755         i2c_set_clientdata(client, NULL);
 756
 757         fb_unregister_client(&dcon->fbevent_nb);
 758         unregister_reboot_notifier(&dcon->reboot_nb);
 759         atomic_notifier_chain_unregister(&panic_notifier_list, &dcon_panic_nb);
 760
 761         free_irq(DCON_IRQ, dcon);
 762
 763         if (dcon_bl_dev != NULL)
 764                 backlight_device_unregister(dcon_bl_dev);
 765
 766         if (dcon_device != NULL)
 767                 platform_device_unregister(dcon_device);
 768         cancel_work_sync(&dcon->switch_source);
 769
 770         kfree(dcon);
 771
 772         return 0;
 773 }
 774
 775 #ifdef CONFIG_PM
 776 static int dcon_suspend(struct i2c_client *client, pm_message_t state)
 777 {
 778         struct dcon_priv *dcon = i2c_get_clientdata(client);
 779
 780         if (!dcon->asleep) {
 781                 /* Set up the DCON to have the source */
 782                 dcon_set_source_sync(dcon, DCON_SOURCE_DCON);
 783         }
 784
 785         return 0;
 786 }
 787
 788 static int dcon_resume(struct i2c_client *client)
 789 {
 790         struct dcon_priv *dcon = i2c_get_clientdata(client);
 791
 792         if (!dcon->asleep) {
 793                 dcon_bus_stabilize(dcon, 0);
 794                 dcon_set_source(dcon, DCON_SOURCE_CPU);
 795         }
 796
 797         return 0;
 798 }
 799
 800 #endif
 801
 802
 803 irqreturn_t dcon_interrupt(int irq, void *id)
 804 {
 805         struct dcon_priv *dcon = id;
 806         int status = pdata->read_status();
 807
 808         if (status == -1)
 809                 return IRQ_NONE;
 810
 811         switch (status & 3) {
 812         case 3:
 813                 printk(KERN_DEBUG "olpc-dcon: DCONLOAD_MISSED interrupt\n");
 814                 break;
 815
 816         case 2: /* switch to DCON mode */
 817         case 1: /* switch to CPU mode */
 818                 dcon_switched = 1;
 819                 getnstimeofday(&dcon_irq_time);
 820                 wake_up(&dcon_wait_queue);
 821                 break;
 822
 823         case 0:
 824                 /* workaround resume case:  the DCON (on 1.5) doesn't
 825                  * ever assert status 0x01 when switching to CPU mode
 826                  * during resume.  this is because DCONLOAD is de-asserted
 827                  * _immediately_ upon exiting S3, so the actual release
 828                  * of the DCON happened long before this point.
 829                  * see http://dev.laptop.org/ticket/9869
 830                  */
 831                 if (dcon->curr_src != dcon->pending_src && !dcon_switched) {
 832                         dcon_switched = 1;
 833                         getnstimeofday(&dcon_irq_time);
 834                         wake_up(&dcon_wait_queue);
 835                         printk(KERN_DEBUG "olpc-dcon: switching w/ status 0/0\n");
 836                 } else {
 837                         printk(KERN_DEBUG "olpc-dcon: scanline interrupt w/CPU\n");
 838                 }
 839         }
 840
 841         return IRQ_HANDLED;
 842 }
 843
 844 static const struct i2c_device_id dcon_idtable[] = {
 845         { "olpc_dcon",  0 },
 846         { }
 847 };
 848
 849 MODULE_DEVICE_TABLE(i2c, dcon_idtable);
 850
 851 struct i2c_driver dcon_driver = {
 852         .driver = {
 853                 .name   = "olpc_dcon",
 854         },
 855         .class = I2C_CLASS_DDC | I2C_CLASS_HWMON,
 856         .id_table = dcon_idtable,
 857         .probe = dcon_probe,
 858         .remove = __devexit_p(dcon_remove),
 859         .detect = dcon_detect,
 860         .address_list = normal_i2c,
 861 #ifdef CONFIG_PM
 862         .suspend = dcon_suspend,
 863         .resume = dcon_resume,
 864 #endif
 865 };
 866
 867 static int __init olpc_dcon_init(void)
 868 {
 869 #ifdef CONFIG_FB_OLPC_DCON_1_5
 870         /* XO-1.5 */
 871         if (olpc_board_at_least(olpc_board(0xd0)))
 872                 pdata = &dcon_pdata_xo_1_5;
 873 #endif
 874 #ifdef CONFIG_FB_OLPC_DCON_1
 875         if (!pdata)
 876                 pdata = &dcon_pdata_xo_1;
 877 #endif
 878
 879         return i2c_add_driver(&dcon_driver);
 880 }
 881
 882 static void __exit olpc_dcon_exit(void)
 883 {
 884         i2c_del_driver(&dcon_driver);
 885 }
 886
 887 module_init(olpc_dcon_init);
 888 module_exit(olpc_dcon_exit);
 889
 890 MODULE_LICENSE("GPL");