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