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 struct dcon_priv {
  57         struct i2c_client *client;
  58
  59         struct work_struct switch_source;
  60         struct notifier_block reboot_nb;
  61
  62         /* Shadow register for the DCON_REG_MODE register */
  63         u8 disp_mode;
  64
  65         /* Current output type; true == mono, false == color */
  66         bool mono;
  67         bool asleep;
  68 };
  69
  70 /* I2C structures */
  71
  72 static struct i2c_driver dcon_driver;
  73
  74 /* Platform devices */
  75 static struct platform_device *dcon_device;
  76
  77 /* Backlight device */
  78 static struct backlight_device *dcon_bl_dev;
  79
  80 static struct fb_info *fbinfo;
  81
  82 /* set this to 1 while controlling fb blank state from this driver */
  83 static int ignore_fb_events = 0;
  84
  85 /* Current source, initialized at probe time */
  86 static int dcon_source;
  87
  88 /* Desired source */
  89 static int dcon_pending;
  90
  91 /* Variables used during switches */
  92 static int dcon_switched;
  93 static struct timespec dcon_irq_time;
  94 static struct timespec dcon_load_time;
  95
  96 static DECLARE_WAIT_QUEUE_HEAD(dcon_wait_queue);
  97
  98 static unsigned short normal_i2c[] = { 0x0d, I2C_CLIENT_END };
  99
 100 static s32 dcon_write(struct dcon_priv *dcon, u8 reg, u16 val)
 101 {
 102         return i2c_smbus_write_word_data(dcon->client, reg, val);
 103 }
 104
 105 static s32 dcon_read(struct dcon_priv *dcon, u8 reg)
 106 {
 107         return i2c_smbus_read_word_data(dcon->client, reg);
 108 }
 109
 110 /* The current backlight value - this saves us some smbus traffic */
 111 static int bl_val = -1;
 112
 113 /* ===== API functions - these are called by a variety of users ==== */
 114
 115 static int dcon_hw_init(struct dcon_priv *dcon, int is_init)
 116 {
 117         struct i2c_client *client = dcon->client;
 118         uint16_t ver;
 119         int rc = 0;
 120
 121         ver = i2c_smbus_read_word_data(client, DCON_REG_ID);
 122         if ((ver >> 8) != 0xDC) {
 123                 printk(KERN_ERR "olpc-dcon:  DCON ID not 0xDCxx: 0x%04x "
 124                                 "instead.\n", ver);
 125                 rc = -ENXIO;
 126                 goto err;
 127         }
 128
 129         if (is_init) {
 130                 printk(KERN_INFO "olpc-dcon:  Discovered DCON version %x\n",
 131                                 ver & 0xFF);
 132                 rc = pdata->init();
 133                 if (rc != 0) {
 134                         printk(KERN_ERR "olpc-dcon:  Unable to init.\n");
 135                         goto err;
 136                 }
 137         }
 138
 139         if (ver < 0xdc02 && !noinit) {
 140                 /* Initialize the DCON registers */
 141
 142                 /* Start with work-arounds for DCON ASIC */
 143                 i2c_smbus_write_word_data(client, 0x4b, 0x00cc);
 144                 i2c_smbus_write_word_data(client, 0x4b, 0x00cc);
 145                 i2c_smbus_write_word_data(client, 0x4b, 0x00cc);
 146                 i2c_smbus_write_word_data(client, 0x0b, 0x007a);
 147                 i2c_smbus_write_word_data(client, 0x36, 0x025c);
 148                 i2c_smbus_write_word_data(client, 0x37, 0x025e);
 149
 150                 /* Initialise SDRAM */
 151
 152                 i2c_smbus_write_word_data(client, 0x3b, 0x002b);
 153                 i2c_smbus_write_word_data(client, 0x41, 0x0101);
 154                 i2c_smbus_write_word_data(client, 0x42, 0x0101);
 155         } else if (!noinit) {
 156                 /* SDRAM setup/hold time */
 157                 i2c_smbus_write_word_data(client, 0x3a, 0xc040);
 158                 i2c_smbus_write_word_data(client, 0x41, 0x0000);
 159                 i2c_smbus_write_word_data(client, 0x41, 0x0101);
 160                 i2c_smbus_write_word_data(client, 0x42, 0x0101);
 161         }
 162
 163         /* Colour swizzle, AA, no passthrough, backlight */
 164         if (is_init) {
 165                 dcon->disp_mode = MODE_PASSTHRU | MODE_BL_ENABLE |
 166                                 MODE_CSWIZZLE;
 167                 if (useaa)
 168                         dcon->disp_mode |= MODE_COL_AA;
 169         }
 170         i2c_smbus_write_word_data(client, DCON_REG_MODE, dcon->disp_mode);
 171
 172
 173         /* Set the scanline to interrupt on during resume */
 174         i2c_smbus_write_word_data(client, DCON_REG_SCAN_INT, resumeline);
 175
 176 err:
 177         return rc;
 178 }
 179
 180 /*
 181  * The smbus doesn't always come back due to what is believed to be
 182  * hardware (power rail) bugs.  For older models where this is known to
 183  * occur, our solution is to attempt to wait for the bus to stabilize;
 184  * if it doesn't happen, cut power to the dcon, repower it, and wait
 185  * for the bus to stabilize.  Rinse, repeat until we have a working
 186  * smbus.  For newer models, we simply BUG(); we want to know if this
 187  * still happens despite the power fixes that have been made!
 188  */
 189 static int dcon_bus_stabilize(struct dcon_priv *dcon, int is_powered_down)
 190 {
 191         unsigned long timeout;
 192         int x;
 193
 194 power_up:
 195         if (is_powered_down) {
 196                 x = 1;
 197                 x = olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0);
 198                 if (x) {
 199                         printk(KERN_WARNING "olpc-dcon:  unable to force dcon "
 200                                         "to power up: %d!\n", x);
 201                         return x;
 202                 }
 203                 msleep(10); /* we'll be conservative */
 204         }
 205
 206         pdata->bus_stabilize_wiggle();
 207
 208         for (x = -1, timeout = 50; timeout && x < 0; timeout--) {
 209                 msleep(1);
 210                 x = dcon_read(dcon, DCON_REG_ID);
 211         }
 212         if (x < 0) {
 213                 printk(KERN_ERR "olpc-dcon:  unable to stabilize dcon's "
 214                                 "smbus, reasserting power and praying.\n");
 215                 BUG_ON(olpc_board_at_least(olpc_board(0xc2)));
 216                 x = 0;
 217                 olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0);
 218                 msleep(100);
 219                 is_powered_down = 1;
 220                 goto power_up;  /* argh, stupid hardware.. */
 221         }
 222
 223         if (is_powered_down)
 224                 return dcon_hw_init(dcon, 0);
 225         return 0;
 226 }
 227
 228 static int dcon_get_backlight(struct dcon_priv *dcon)
 229 {
 230         if (!dcon || !dcon->client)
 231                 return 0;
 232
 233         if (bl_val == -1)
 234                 bl_val = dcon_read(dcon, DCON_REG_BRIGHT) & 0x0F;
 235
 236         return bl_val;
 237 }
 238
 239
 240 static void dcon_set_backlight_hw(struct dcon_priv *dcon, int level)
 241 {
 242         bl_val = level & 0x0F;
 243         dcon_write(dcon, DCON_REG_BRIGHT, bl_val);
 244
 245         /* Purposely turn off the backlight when we go to level 0 */
 246         if (bl_val == 0) {
 247                 dcon->disp_mode &= ~MODE_BL_ENABLE;
 248                 dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
 249         } else if (!(dcon->disp_mode & MODE_BL_ENABLE)) {
 250                 dcon->disp_mode |= MODE_BL_ENABLE;
 251                 dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
 252         }
 253 }
 254
 255 static void dcon_set_backlight(struct dcon_priv *dcon, int level)
 256 {
 257         if (!dcon || !dcon->client)
 258                 return;
 259
 260         if (bl_val == (level & 0x0F))
 261                 return;
 262
 263         dcon_set_backlight_hw(dcon, level);
 264 }
 265
 266 /* Set the output type to either color or mono */
 267 static int dcon_set_mono_mode(struct dcon_priv *dcon, bool enable_mono)
 268 {
 269         if (dcon->mono == enable_mono)
 270                 return 0;
 271
 272         dcon->mono = enable_mono;
 273
 274         if (enable_mono) {
 275                 dcon->disp_mode &= ~(MODE_CSWIZZLE | MODE_COL_AA);
 276                 dcon->disp_mode |= MODE_MONO_LUMA;
 277         } else {
 278                 dcon->disp_mode &= ~(MODE_MONO_LUMA);
 279                 dcon->disp_mode |= MODE_CSWIZZLE;
 280                 if (useaa)
 281                         dcon->disp_mode |= MODE_COL_AA;
 282         }
 283
 284         dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
 285         return 0;
 286 }
 287
 288 /* For now, this will be really stupid - we need to address how
 289  * DCONLOAD works in a sleep and account for it accordingly
 290  */
 291
 292 static void dcon_sleep(struct dcon_priv *dcon, bool sleep)
 293 {
 294         int x;
 295
 296         /* Turn off the backlight and put the DCON to sleep */
 297
 298         if (dcon->asleep == sleep)
 299                 return;
 300
 301         if (!olpc_board_at_least(olpc_board(0xc2)))
 302                 return;
 303
 304         if (sleep) {
 305                 x = 0;
 306                 x = olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0);
 307                 if (x)
 308                         printk(KERN_WARNING "olpc-dcon:  unable to force dcon "
 309                                         "to power down: %d!\n", x);
 310                 else
 311                         dcon->asleep = sleep;
 312         } else {
 313                 /* Only re-enable the backlight if the backlight value is set */
 314                 if (bl_val != 0)
 315                         dcon->disp_mode |= MODE_BL_ENABLE;
 316                 x = dcon_bus_stabilize(dcon, 1);
 317                 if (x)
 318                         printk(KERN_WARNING "olpc-dcon:  unable to reinit dcon"
 319                                         " hardware: %d!\n", x);
 320                 else
 321                         dcon->asleep = sleep;
 322
 323                 /* Restore backlight */
 324                 dcon_set_backlight_hw(dcon, bl_val);
 325         }
 326
 327         /* We should turn off some stuff in the framebuffer - but what? */
 328 }
 329
 330 /* the DCON seems to get confused if we change DCONLOAD too
 331  * frequently -- i.e., approximately faster than frame time.
 332  * normally we don't change it this fast, so in general we won't
 333  * delay here.
 334  */
 335 void dcon_load_holdoff(void)
 336 {
 337         struct timespec delta_t, now;
 338         while (1) {
 339                 getnstimeofday(&now);
 340                 delta_t = timespec_sub(now, dcon_load_time);
 341                 if (delta_t.tv_sec != 0 ||
 342                         delta_t.tv_nsec > NSEC_PER_MSEC * 20) {
 343                         break;
 344                 }
 345                 mdelay(4);
 346         }
 347 }
 348 /* Set the source of the display (CPU or DCON) */
 349
 350 static void dcon_source_switch(struct work_struct *work)
 351 {
 352         struct dcon_priv *dcon = container_of(work, struct dcon_priv,
 353                         switch_source);
 354         DECLARE_WAITQUEUE(wait, current);
 355         int source = dcon_pending;
 356
 357         if (dcon_source == source)
 358                 return;
 359
 360         dcon_load_holdoff();
 361
 362         dcon_switched = 0;
 363
 364         switch (source) {
 365         case DCON_SOURCE_CPU:
 366                 printk("dcon_source_switch to CPU\n");
 367                 /* Enable the scanline interrupt bit */
 368                 if (dcon_write(dcon, DCON_REG_MODE,
 369                                 dcon->disp_mode | MODE_SCAN_INT))
 370                         printk(KERN_ERR
 371                                "olpc-dcon:  couldn't enable scanline interrupt!\n");
 372                 else {
 373                         /* Wait up to one second for the scanline interrupt */
 374                         wait_event_timeout(dcon_wait_queue,
 375                                            dcon_switched == 1, HZ);
 376                 }
 377
 378                 if (!dcon_switched)
 379                         printk(KERN_ERR "olpc-dcon:  Timeout entering CPU mode; expect a screen glitch.\n");
 380
 381                 /* Turn off the scanline interrupt */
 382                 if (dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode))
 383                         printk(KERN_ERR "olpc-dcon:  couldn't disable scanline interrupt!\n");
 384
 385                 /*
 386                  * Ideally we'd like to disable interrupts here so that the
 387                  * fb unblanking and DCON turn on happen at a known time value;
 388                  * however, we can't do that right now with fb_blank
 389                  * messing with semaphores.
 390                  *
 391                  * For now, we just hope..
 392                  */
 393                 console_lock();
 394                 ignore_fb_events = 1;
 395                 if (fb_blank(fbinfo, FB_BLANK_UNBLANK)) {
 396                         ignore_fb_events = 0;
 397                         console_unlock();
 398                         printk(KERN_ERR "olpc-dcon:  Failed to enter CPU mode\n");
 399                         dcon_pending = DCON_SOURCE_DCON;
 400                         return;
 401                 }
 402                 ignore_fb_events = 0;
 403                 console_unlock();
 404
 405                 /* And turn off the DCON */
 406                 pdata->set_dconload(1);
 407                 getnstimeofday(&dcon_load_time);
 408
 409                 printk(KERN_INFO "olpc-dcon: The CPU has control\n");
 410                 break;
 411         case DCON_SOURCE_DCON:
 412         {
 413                 int t;
 414                 struct timespec delta_t;
 415
 416                 printk(KERN_INFO "dcon_source_switch to DCON\n");
 417
 418                 add_wait_queue(&dcon_wait_queue, &wait);
 419                 set_current_state(TASK_UNINTERRUPTIBLE);
 420
 421                 /* Clear DCONLOAD - this implies that the DCON is in control */
 422                 pdata->set_dconload(0);
 423                 getnstimeofday(&dcon_load_time);
 424
 425                 t = schedule_timeout(HZ/2);
 426                 remove_wait_queue(&dcon_wait_queue, &wait);
 427                 set_current_state(TASK_RUNNING);
 428
 429                 if (!dcon_switched) {
 430                         printk(KERN_ERR "olpc-dcon: Timeout entering DCON mode; expect a screen glitch.\n");
 431                 } else {
 432                         /* sometimes the DCON doesn't follow its own rules,
 433                          * and doesn't wait for two vsync pulses before
 434                          * ack'ing the frame load with an IRQ.  the result
 435                          * is that the display shows the *previously*
 436                          * loaded frame.  we can detect this by looking at
 437                          * the time between asserting DCONLOAD and the IRQ --
 438                          * if it's less than 20msec, then the DCON couldn't
 439                          * have seen two VSYNC pulses.  in that case we
 440                          * deassert and reassert, and hope for the best.
 441                          * see http://dev.laptop.org/ticket/9664
 442                          */
 443                         delta_t = timespec_sub(dcon_irq_time, dcon_load_time);
 444                         if (dcon_switched && delta_t.tv_sec == 0 &&
 445                                         delta_t.tv_nsec < NSEC_PER_MSEC * 20) {
 446                                 printk(KERN_ERR "olpc-dcon: missed loading, retrying\n");
 447                                 pdata->set_dconload(1);
 448                                 mdelay(41);
 449                                 pdata->set_dconload(0);
 450                                 getnstimeofday(&dcon_load_time);
 451                                 mdelay(41);
 452                         }
 453                 }
 454
 455                 console_lock();
 456                 ignore_fb_events = 1;
 457                 if (fb_blank(fbinfo, FB_BLANK_POWERDOWN))
 458                         printk(KERN_ERR "olpc-dcon:  couldn't blank fb!\n");
 459                 ignore_fb_events = 0;
 460                 console_unlock();
 461
 462                 printk(KERN_INFO "olpc-dcon: The DCON has control\n");
 463                 break;
 464         }
 465         default:
 466                 BUG();
 467         }
 468
 469         dcon_source = source;
 470 }
 471
 472 static void dcon_set_source(struct dcon_priv *dcon, int arg)
 473 {
 474         if (dcon_pending == arg)
 475                 return;
 476
 477         dcon_pending = arg;
 478
 479         if ((dcon_source != arg) && !work_pending(&dcon->switch_source))
 480                 schedule_work(&dcon->switch_source);
 481 }
 482
 483 static void dcon_set_source_sync(struct dcon_priv *dcon, int arg)
 484 {
 485         dcon_set_source(dcon, arg);
 486         flush_scheduled_work();
 487 }
 488
 489 static int dconbl_set(struct backlight_device *dev)
 490 {
 491         struct dcon_priv *dcon = bl_get_data(dev);
 492         int level = dev->props.brightness;
 493
 494         if (dev->props.power != FB_BLANK_UNBLANK)
 495                 level = 0;
 496
 497         dcon_set_backlight(dcon, level);
 498         return 0;
 499 }
 500
 501 static int dconbl_get(struct backlight_device *dev)
 502 {
 503         struct dcon_priv *dcon = bl_get_data(dev);
 504         return dcon_get_backlight(dcon);
 505 }
 506
 507 static ssize_t dcon_mode_show(struct device *dev,
 508         struct device_attribute *attr, char *buf)
 509 {
 510         struct dcon_priv *dcon = dev_get_drvdata(dev);
 511         return sprintf(buf, "%4.4X\n", dcon->disp_mode);
 512 }
 513
 514 static ssize_t dcon_sleep_show(struct device *dev,
 515         struct device_attribute *attr, char *buf)
 516 {
 517
 518         struct dcon_priv *dcon = dev_get_drvdata(dev);
 519         return sprintf(buf, "%d\n", dcon->asleep);
 520 }
 521
 522 static ssize_t dcon_freeze_show(struct device *dev,
 523         struct device_attribute *attr, char *buf)
 524 {
 525         return sprintf(buf, "%d\n", dcon_source == DCON_SOURCE_DCON ? 1 : 0);
 526 }
 527
 528 static ssize_t dcon_mono_show(struct device *dev,
 529         struct device_attribute *attr, char *buf)
 530 {
 531         struct dcon_priv *dcon = dev_get_drvdata(dev);
 532         return sprintf(buf, "%d\n", dcon->mono);
 533 }
 534
 535 static ssize_t dcon_resumeline_show(struct device *dev,
 536         struct device_attribute *attr, char *buf)
 537 {
 538         return sprintf(buf, "%d\n", resumeline);
 539 }
 540
 541 static int _strtoul(const char *buf, int len, unsigned int *val)
 542 {
 543
 544         char *endp;
 545         unsigned int output = simple_strtoul(buf, &endp, 0);
 546         int size = endp - buf;
 547
 548         if (*endp && isspace(*endp))
 549                 size++;
 550
 551         if (size != len)
 552                 return -EINVAL;
 553
 554         *val = output;
 555         return 0;
 556 }
 557
 558 static ssize_t dcon_mono_store(struct device *dev,
 559         struct device_attribute *attr, const char *buf, size_t count)
 560 {
 561         int enable_mono;
 562         int rc = -EINVAL;
 563
 564         if (_strtoul(buf, count, &enable_mono))
 565                 return -EINVAL;
 566
 567         dcon_set_mono_mode(dev_get_drvdata(dev), enable_mono ? true : false);
 568         rc = count;
 569
 570         return rc;
 571 }
 572
 573 static ssize_t dcon_freeze_store(struct device *dev,
 574         struct device_attribute *attr, const char *buf, size_t count)
 575 {
 576         struct dcon_priv *dcon = dev_get_drvdata(dev);
 577         int output;
 578
 579         if (_strtoul(buf, count, &output))
 580                 return -EINVAL;
 581
 582         printk(KERN_INFO "dcon_freeze_store: %d\n", output);
 583
 584         switch (output) {
 585         case 0:
 586                 dcon_set_source(dcon, DCON_SOURCE_CPU);
 587                 break;
 588         case 1:
 589                 dcon_set_source_sync(dcon, DCON_SOURCE_DCON);
 590                 break;
 591         case 2:  /* normally unused */
 592                 dcon_set_source(dcon, DCON_SOURCE_DCON);
 593                 break;
 594         default:
 595                 return -EINVAL;
 596         }
 597
 598         return count;
 599 }
 600
 601 static ssize_t dcon_resumeline_store(struct device *dev,
 602         struct device_attribute *attr, const char *buf, size_t count)
 603 {
 604         int rl;
 605         int rc = -EINVAL;
 606
 607         if (_strtoul(buf, count, &rl))
 608                 return rc;
 609
 610         resumeline = rl;
 611         dcon_write(dev_get_drvdata(dev), DCON_REG_SCAN_INT, resumeline);
 612         rc = count;
 613
 614         return rc;
 615 }
 616
 617 static ssize_t dcon_sleep_store(struct device *dev,
 618         struct device_attribute *attr, const char *buf, size_t count)
 619 {
 620         int output;
 621
 622         if (_strtoul(buf, count, &output))
 623                 return -EINVAL;
 624
 625         dcon_sleep(dev_get_drvdata(dev), output ? true : false);
 626         return count;
 627 }
 628
 629 static struct device_attribute dcon_device_files[] = {
 630         __ATTR(mode, 0444, dcon_mode_show, NULL),
 631         __ATTR(sleep, 0644, dcon_sleep_show, dcon_sleep_store),
 632         __ATTR(freeze, 0644, dcon_freeze_show, dcon_freeze_store),
 633         __ATTR(monochrome, 0644, dcon_mono_show, dcon_mono_store),
 634         __ATTR(resumeline, 0644, dcon_resumeline_show, dcon_resumeline_store),
 635 };
 636
 637 static const struct backlight_ops dcon_bl_ops = {
 638         .get_brightness = dconbl_get,
 639         .update_status = dconbl_set
 640 };
 641
 642
 643 static int dcon_reboot_notify(struct notifier_block *nb,
 644                               unsigned long foo, void *bar)
 645 {
 646         struct dcon_priv *dcon = container_of(nb, struct dcon_priv, reboot_nb);
 647
 648         if (!dcon || !dcon->client)
 649                 return 0;
 650
 651         /* Turn off the DCON. Entirely. */
 652         dcon_write(dcon, DCON_REG_MODE, 0x39);
 653         dcon_write(dcon, DCON_REG_MODE, 0x32);
 654         return 0;
 655 }
 656
 657 static int unfreeze_on_panic(struct notifier_block *nb,
 658                              unsigned long e, void *p)
 659 {
 660         pdata->set_dconload(1);
 661         return NOTIFY_DONE;
 662 }
 663
 664 static struct notifier_block dcon_panic_nb = {
 665         .notifier_call = unfreeze_on_panic,
 666 };
 667
 668 /*
 669  * When the framebuffer sleeps due to external sources (e.g. user idle), power
 670  * down the DCON as well.  Power it back up when the fb comes back to life.
 671  */
 672 static int fb_notifier_callback(struct notifier_block *self,
 673                                 unsigned long event, void *data)
 674 {
 675         struct fb_event *evdata = data;
 676         struct backlight_device *bl = container_of(self,
 677                         struct backlight_device, fb_notif);
 678         struct dcon_priv *dcon = bl_get_data(bl);
 679         int *blank = (int *) evdata->data;
 680         if (((event != FB_EVENT_BLANK) && (event != FB_EVENT_CONBLANK)) ||
 681                         ignore_fb_events)
 682                 return 0;
 683         dcon_sleep(dcon, *blank ? true : false);
 684         return 0;
 685 }
 686
 687 static struct notifier_block fb_nb = {
 688         .notifier_call = fb_notifier_callback,
 689 };
 690
 691 static int dcon_detect(struct i2c_client *client, struct i2c_board_info *info)
 692 {
 693         strlcpy(info->type, "olpc_dcon", I2C_NAME_SIZE);
 694
 695         return 0;
 696 }
 697
 698 static int dcon_probe(struct i2c_client *client, const struct i2c_device_id *id)
 699 {
 700         struct dcon_priv *dcon;
 701         int rc, i, j;
 702
 703         dcon = kzalloc(sizeof(*dcon), GFP_KERNEL);
 704         if (!dcon)
 705                 return -ENOMEM;
 706
 707         dcon->client = client;
 708         INIT_WORK(&dcon->switch_source, dcon_source_switch);
 709         dcon->reboot_nb.notifier_call = dcon_reboot_notify;
 710         dcon->reboot_nb.priority = -1;
 711
 712         i2c_set_clientdata(client, dcon);
 713
 714         if (num_registered_fb >= 1)
 715                 fbinfo = registered_fb[0];
 716
 717         rc = dcon_hw_init(dcon, 1);
 718         if (rc)
 719                 goto einit;
 720
 721         /* Add the DCON device */
 722
 723         dcon_device = platform_device_alloc("dcon", -1);
 724
 725         if (dcon_device == NULL) {
 726                 printk(KERN_ERR "dcon:  Unable to create the DCON device\n");
 727                 rc = -ENOMEM;
 728                 goto eirq;
 729         }
 730         rc = platform_device_add(dcon_device);
 731         platform_set_drvdata(dcon_device, dcon);
 732
 733         if (rc) {
 734                 printk(KERN_ERR "dcon:  Unable to add the DCON device\n");
 735                 goto edev;
 736         }
 737
 738         for (i = 0; i < ARRAY_SIZE(dcon_device_files); i++) {
 739                 rc = device_create_file(&dcon_device->dev,
 740                                         &dcon_device_files[i]);
 741                 if (rc) {
 742                         dev_err(&dcon_device->dev, "Cannot create sysfs file\n");
 743                         goto ecreate;
 744                 }
 745         }
 746
 747         /* Add the backlight device for the DCON */
 748         dcon_bl_dev = backlight_device_register("dcon-bl", &dcon_device->dev,
 749                 dcon, &dcon_bl_ops, NULL);
 750
 751         if (IS_ERR(dcon_bl_dev)) {
 752                 printk(KERN_ERR "Cannot register the backlight device (%ld)\n",
 753                        PTR_ERR(dcon_bl_dev));
 754                 dcon_bl_dev = NULL;
 755         } else {
 756                 dcon_bl_dev->props.max_brightness = 15;
 757                 dcon_bl_dev->props.power = FB_BLANK_UNBLANK;
 758                 dcon_bl_dev->props.brightness = dcon_get_backlight(dcon);
 759
 760                 backlight_update_status(dcon_bl_dev);
 761         }
 762
 763         register_reboot_notifier(&dcon->reboot_nb);
 764         atomic_notifier_chain_register(&panic_notifier_list, &dcon_panic_nb);
 765         fb_register_client(&fb_nb);
 766
 767         return 0;
 768
 769  ecreate:
 770         for (j = 0; j < i; j++)
 771                 device_remove_file(&dcon_device->dev, &dcon_device_files[j]);
 772  edev:
 773         platform_device_unregister(dcon_device);
 774         dcon_device = NULL;
 775  eirq:
 776         free_irq(DCON_IRQ, &dcon_driver);
 777  einit:
 778         i2c_set_clientdata(client, NULL);
 779         kfree(dcon);
 780         return rc;
 781 }
 782
 783 static int dcon_remove(struct i2c_client *client)
 784 {
 785         struct dcon_priv *dcon = i2c_get_clientdata(client);
 786
 787         i2c_set_clientdata(client, NULL);
 788
 789         fb_unregister_client(&fb_nb);
 790         unregister_reboot_notifier(&dcon->reboot_nb);
 791         atomic_notifier_chain_unregister(&panic_notifier_list, &dcon_panic_nb);
 792
 793         free_irq(DCON_IRQ, &dcon_driver);
 794
 795         if (dcon_bl_dev != NULL)
 796                 backlight_device_unregister(dcon_bl_dev);
 797
 798         if (dcon_device != NULL)
 799                 platform_device_unregister(dcon_device);
 800         cancel_work_sync(&dcon->switch_source);
 801
 802         kfree(dcon);
 803
 804         return 0;
 805 }
 806
 807 #ifdef CONFIG_PM
 808 static int dcon_suspend(struct i2c_client *client, pm_message_t state)
 809 {
 810         struct dcon_priv *dcon = i2c_get_clientdata(client);
 811
 812         if (!dcon->asleep) {
 813                 /* Set up the DCON to have the source */
 814                 dcon_set_source_sync(dcon, DCON_SOURCE_DCON);
 815         }
 816
 817         return 0;
 818 }
 819
 820 static int dcon_resume(struct i2c_client *client)
 821 {
 822         struct dcon_priv *dcon = i2c_get_clientdata(client);
 823
 824         if (!dcon->asleep) {
 825                 dcon_bus_stabilize(dcon, 0);
 826                 dcon_set_source(dcon, DCON_SOURCE_CPU);
 827         }
 828
 829         return 0;
 830 }
 831
 832 #endif
 833
 834
 835 static irqreturn_t dcon_interrupt(int irq, void *id)
 836 {
 837         int status = pdata->read_status();
 838
 839         if (status == -1)
 840                 return IRQ_NONE;
 841
 842         switch (status & 3) {
 843         case 3:
 844                 printk(KERN_DEBUG "olpc-dcon: DCONLOAD_MISSED interrupt\n");
 845                 break;
 846
 847         case 2: /* switch to DCON mode */
 848         case 1: /* switch to CPU mode */
 849                 dcon_switched = 1;
 850                 getnstimeofday(&dcon_irq_time);
 851                 wake_up(&dcon_wait_queue);
 852                 break;
 853
 854         case 0:
 855                 /* workaround resume case:  the DCON (on 1.5) doesn't
 856                  * ever assert status 0x01 when switching to CPU mode
 857                  * during resume.  this is because DCONLOAD is de-asserted
 858                  * _immediately_ upon exiting S3, so the actual release
 859                  * of the DCON happened long before this point.
 860                  * see http://dev.laptop.org/ticket/9869
 861                  */
 862                 if (dcon_source != dcon_pending && !dcon_switched) {
 863                         dcon_switched = 1;
 864                         getnstimeofday(&dcon_irq_time);
 865                         wake_up(&dcon_wait_queue);
 866                         printk(KERN_DEBUG "olpc-dcon: switching w/ status 0/0\n");
 867                 } else {
 868                         printk(KERN_DEBUG "olpc-dcon: scanline interrupt w/CPU\n");
 869                 }
 870         }
 871
 872         return IRQ_HANDLED;
 873 }
 874
 875 static const struct i2c_device_id dcon_idtable[] = {
 876         { "olpc_dcon",  0 },
 877         { }
 878 };
 879
 880 MODULE_DEVICE_TABLE(i2c, dcon_idtable);
 881
 882 static struct i2c_driver dcon_driver = {
 883         .driver = {
 884                 .name   = "olpc_dcon",
 885         },
 886         .class = I2C_CLASS_DDC | I2C_CLASS_HWMON,
 887         .id_table = dcon_idtable,
 888         .probe = dcon_probe,
 889         .remove = __devexit_p(dcon_remove),
 890         .detect = dcon_detect,
 891         .address_list = normal_i2c,
 892 #ifdef CONFIG_PM
 893         .suspend = dcon_suspend,
 894         .resume = dcon_resume,
 895 #endif
 896 };
 897
 898 #include "olpc_dcon_xo_1.c"
 899
 900 static int __init olpc_dcon_init(void)
 901 {
 902         pdata = &dcon_pdata_xo_1;
 903
 904         return i2c_add_driver(&dcon_driver);
 905 }
 906
 907 static void __exit olpc_dcon_exit(void)
 908 {
 909         i2c_del_driver(&dcon_driver);
 910 }
 911
 912 module_init(olpc_dcon_init);
 913 module_exit(olpc_dcon_exit);
 914
 915 MODULE_LICENSE("GPL");