drivers/staging/olpc_dcon/olpc_dcon.c

   1 /*
   2  * Mainly by David Woodhouse, somewhat modified by Jordan Crouse
   3  *
   4  * Copyright © 2006-2007  Red Hat, Inc.
   5  * Copyright © 2006-2007  Advanced Micro Devices, Inc.
   6  * Copyright © 2009       VIA Technology, Inc.
   7  * Copyright (c) 2010  Andres Salomon <dilinger@queued.net>
   8  *
   9  * This program is free software.  You can redistribute it and/or
  10  * modify it under the terms of version 2 of the GNU General Public
  11  * License as published by the Free Software Foundation.
  12  */
  13
  14
  15 #include <linux/kernel.h>
  16 #include <linux/fb.h>
  17 #include <linux/console.h>
  18 #include <linux/i2c.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/pci.h>
  21 #include <linux/pci_ids.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/delay.h>
  24 #include <linux/backlight.h>
  25 #include <linux/device.h>
  26 #include <linux/notifier.h>
  27 #include <asm/uaccess.h>
  28 #include <linux/ctype.h>
  29 #include <linux/reboot.h>
  30 #include <linux/gpio.h>
  31 #include <asm/tsc.h>
  32 #include <asm/olpc.h>
  33
  34 #include "olpc_dcon.h"
  35
  36 /* Module definitions */
  37
  38 static int resumeline = 898;
  39 module_param(resumeline, int, 0444);
  40
  41 static int noinit;
  42 module_param(noinit, int, 0444);
  43
  44 /* Default off since it doesn't work on DCON ASIC in B-test OLPC board */
  45 static int useaa = 1;
  46 module_param(useaa, int, 0444);
  47
  48 struct dcon_platform_data {
  49         int (*init)(void);
  50         void (*bus_stabilize_wiggle)(void);
  51         void (*set_dconload)(int);
  52         int (*read_status)(void);
  53 };
  54
  55 static struct dcon_platform_data *pdata;
  56
  57 /* I2C structures */
  58
  59 static struct i2c_driver dcon_driver;
  60 static struct i2c_client *dcon_client;
  61
  62 /* Platform devices */
  63 static struct platform_device *dcon_device;
  64
  65 /* Backlight device */
  66 static struct backlight_device *dcon_bl_dev;
  67
  68 static struct fb_info *fbinfo;
  69
  70 /* set this to 1 while controlling fb blank state from this driver */
  71 static int ignore_fb_events = 0;
  72
  73 /* Current source, initialized at probe time */
  74 static int dcon_source;
  75
  76 /* Desired source */
  77 static int dcon_pending;
  78
  79 /* Current output type */
  80 static int dcon_output = DCON_OUTPUT_COLOR;
  81
  82 /* Current sleep status (not yet implemented) */
  83 static int dcon_sleep_val = DCON_ACTIVE;
  84
  85 /* Shadow register for the DCON_REG_MODE register */
  86 static unsigned short dcon_disp_mode;
  87
  88 /* Variables used during switches */
  89 static int dcon_switched;
  90 static struct timespec dcon_irq_time;
  91 static struct timespec dcon_load_time;
  92
  93 static DECLARE_WAIT_QUEUE_HEAD(dcon_wait_queue);
  94
  95 static unsigned short normal_i2c[] = { 0x0d, I2C_CLIENT_END };
  96
  97 #define dcon_write(reg,val) i2c_smbus_write_word_data(dcon_client,reg,val)
  98 #define dcon_read(reg) i2c_smbus_read_word_data(dcon_client,reg)
  99
 100 /* The current backlight value - this saves us some smbus traffic */
 101 static int bl_val = -1;
 102
 103 /* ===== API functions - these are called by a variety of users ==== */
 104
 105 static int dcon_hw_init(struct i2c_client *client, int is_init)
 106 {
 107         uint16_t ver;
 108         int rc = 0;
 109
 110         ver = i2c_smbus_read_word_data(client, DCON_REG_ID);
 111         if ((ver >> 8) != 0xDC) {
 112                 printk(KERN_ERR "olpc-dcon:  DCON ID not 0xDCxx: 0x%04x "
 113                                 "instead.\n", ver);
 114                 rc = -ENXIO;
 115                 goto err;
 116         }
 117
 118         if (is_init) {
 119                 printk(KERN_INFO "olpc-dcon:  Discovered DCON version %x\n",
 120                                 ver & 0xFF);
 121                 if ((rc = pdata->init()) != 0) {
 122                         printk(KERN_ERR "olpc-dcon:  Unable to init.\n");
 123                         goto err;
 124                 }
 125         }
 126
 127         if (ver < 0xdc02 && !noinit) {
 128                 /* Initialize the DCON registers */
 129
 130                 /* Start with work-arounds for DCON ASIC */
 131                 i2c_smbus_write_word_data(client, 0x4b, 0x00cc);
 132                 i2c_smbus_write_word_data(client, 0x4b, 0x00cc);
 133                 i2c_smbus_write_word_data(client, 0x4b, 0x00cc);
 134                 i2c_smbus_write_word_data(client, 0x0b, 0x007a);
 135                 i2c_smbus_write_word_data(client, 0x36, 0x025c);
 136                 i2c_smbus_write_word_data(client, 0x37, 0x025e);
 137
 138                 /* Initialise SDRAM */
 139
 140                 i2c_smbus_write_word_data(client, 0x3b, 0x002b);
 141                 i2c_smbus_write_word_data(client, 0x41, 0x0101);
 142                 i2c_smbus_write_word_data(client, 0x42, 0x0101);
 143         }
 144         else if (!noinit) {
 145                 /* SDRAM setup/hold time */
 146                 i2c_smbus_write_word_data(client, 0x3a, 0xc040);
 147                 i2c_smbus_write_word_data(client, 0x41, 0x0000);
 148                 i2c_smbus_write_word_data(client, 0x41, 0x0101);
 149                 i2c_smbus_write_word_data(client, 0x42, 0x0101);
 150         }
 151
 152         /* Colour swizzle, AA, no passthrough, backlight */
 153         if (is_init) {
 154                 dcon_disp_mode = MODE_PASSTHRU | MODE_BL_ENABLE | MODE_CSWIZZLE;
 155                 if (useaa)
 156                         dcon_disp_mode |= MODE_COL_AA;
 157         }
 158         i2c_smbus_write_word_data(client, DCON_REG_MODE, dcon_disp_mode);
 159
 160
 161         /* Set the scanline to interrupt on during resume */
 162         i2c_smbus_write_word_data(client, DCON_REG_SCAN_INT, resumeline);
 163
 164 err:
 165         return rc;
 166 }
 167
 168 /*
 169  * The smbus doesn't always come back due to what is believed to be
 170  * hardware (power rail) bugs.  For older models where this is known to
 171  * occur, our solution is to attempt to wait for the bus to stabilize;
 172  * if it doesn't happen, cut power to the dcon, repower it, and wait
 173  * for the bus to stabilize.  Rinse, repeat until we have a working
 174  * smbus.  For newer models, we simply BUG(); we want to know if this
 175  * still happens despite the power fixes that have been made!
 176  */
 177 static int dcon_bus_stabilize(struct i2c_client *client, int is_powered_down)
 178 {
 179         unsigned long timeout;
 180         int x;
 181
 182 power_up:
 183         if (is_powered_down) {
 184                 x = 1;
 185                 if ((x = olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0))) {
 186                         printk(KERN_WARNING "olpc-dcon:  unable to force dcon "
 187                                         "to power up: %d!\n", x);
 188                         return x;
 189                 }
 190                 msleep(10); /* we'll be conservative */
 191         }
 192
 193         pdata->bus_stabilize_wiggle();
 194
 195         for (x = -1, timeout = 50; timeout && x < 0; timeout--) {
 196                 msleep(1);
 197                 x = dcon_read(DCON_REG_ID);
 198         }
 199         if (x < 0) {
 200                 printk(KERN_ERR "olpc-dcon:  unable to stabilize dcon's "
 201                                 "smbus, reasserting power and praying.\n");
 202                 BUG_ON(olpc_board_at_least(olpc_board(0xc2)));
 203                 x = 0;
 204                 olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0);
 205                 msleep(100);
 206                 is_powered_down = 1;
 207                 goto power_up;  /* argh, stupid hardware.. */
 208         }
 209
 210         if (is_powered_down)
 211                 return dcon_hw_init(client, 0);
 212         return 0;
 213 }
 214
 215 static int dcon_get_backlight(void)
 216 {
 217         if (dcon_client == NULL)
 218                 return 0;
 219
 220         if (bl_val == -1)
 221                 bl_val = dcon_read(DCON_REG_BRIGHT) & 0x0F;
 222
 223         return bl_val;
 224 }
 225
 226
 227 static void dcon_set_backlight_hw(int level)
 228 {
 229         bl_val = level & 0x0F;
 230         dcon_write(DCON_REG_BRIGHT, bl_val);
 231
 232         /* Purposely turn off the backlight when we go to level 0 */
 233         if (bl_val == 0) {
 234                 dcon_disp_mode &= ~MODE_BL_ENABLE;
 235                 dcon_write(DCON_REG_MODE, dcon_disp_mode);
 236         } else if (!(dcon_disp_mode & MODE_BL_ENABLE)) {
 237                 dcon_disp_mode |= MODE_BL_ENABLE;
 238                 dcon_write(DCON_REG_MODE, dcon_disp_mode);
 239         }
 240 }
 241
 242 static void dcon_set_backlight(int level)
 243 {
 244         if (dcon_client == NULL)
 245                 return;
 246
 247         if (bl_val == (level & 0x0F))
 248                 return;
 249
 250         dcon_set_backlight_hw(level);
 251 }
 252
 253 /* Set the output type to either color or mono */
 254
 255 static int dcon_set_output(int arg)
 256 {
 257         if (dcon_output == arg)
 258                 return 0;
 259
 260         dcon_output = arg;
 261
 262         if (arg == DCON_OUTPUT_MONO) {
 263                 dcon_disp_mode &= ~(MODE_CSWIZZLE | MODE_COL_AA);
 264                 dcon_disp_mode |= MODE_MONO_LUMA;
 265         }
 266         else {
 267                 dcon_disp_mode &= ~(MODE_MONO_LUMA);
 268                 dcon_disp_mode |= MODE_CSWIZZLE;
 269                 if (useaa)
 270                         dcon_disp_mode |= MODE_COL_AA;
 271         }
 272
 273         dcon_write(DCON_REG_MODE, dcon_disp_mode);
 274         return 0;
 275 }
 276
 277 /* For now, this will be really stupid - we need to address how
 278  * DCONLOAD works in a sleep and account for it accordingly
 279  */
 280
 281 static void dcon_sleep(int state)
 282 {
 283         int x;
 284
 285         /* Turn off the backlight and put the DCON to sleep */
 286
 287         if (state == dcon_sleep_val)
 288                 return;
 289
 290         if (!olpc_board_at_least(olpc_board(0xc2)))
 291                 return;
 292
 293         if (state == DCON_SLEEP) {
 294                 x = 0;
 295                 if ((x = olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0)))
 296                         printk(KERN_WARNING "olpc-dcon:  unable to force dcon "
 297                                         "to power down: %d!\n", x);
 298                 else
 299                         dcon_sleep_val = state;
 300         }
 301         else {
 302                 /* Only re-enable the backlight if the backlight value is set */
 303                 if (bl_val != 0)
 304                         dcon_disp_mode |= MODE_BL_ENABLE;
 305
 306                 if ((x=dcon_bus_stabilize(dcon_client, 1)))
 307                         printk(KERN_WARNING "olpc-dcon:  unable to reinit dcon"
 308                                         " hardware: %d!\n", x);
 309                 else
 310                         dcon_sleep_val = state;
 311
 312                 /* Restore backlight */
 313                 dcon_set_backlight_hw(bl_val);
 314         }
 315
 316         /* We should turn off some stuff in the framebuffer - but what? */
 317 }
 318
 319 /* the DCON seems to get confused if we change DCONLOAD too
 320  * frequently -- i.e., approximately faster than frame time.
 321  * normally we don't change it this fast, so in general we won't
 322  * delay here.
 323  */
 324 void dcon_load_holdoff(void)
 325 {
 326         struct timespec delta_t, now;
 327         while(1) {
 328                 getnstimeofday(&now);
 329                 delta_t = timespec_sub(now, dcon_load_time);
 330                 if (delta_t.tv_sec != 0 ||
 331                         delta_t.tv_nsec > NSEC_PER_MSEC * 20) {
 332                         break;
 333                 }
 334                 mdelay(4);
 335         }
 336 }
 337 /* Set the source of the display (CPU or DCON) */
 338
 339 static void dcon_source_switch(struct work_struct *work)
 340 {
 341         DECLARE_WAITQUEUE(wait, current);
 342         int source = dcon_pending;
 343
 344         if (dcon_source == source)
 345                 return;
 346
 347         dcon_load_holdoff();
 348
 349         dcon_switched = 0;
 350
 351         switch (source) {
 352         case DCON_SOURCE_CPU:
 353                 printk("dcon_source_switch to CPU\n");
 354                 /* Enable the scanline interrupt bit */
 355                 if (dcon_write(DCON_REG_MODE, dcon_disp_mode | MODE_SCAN_INT))
 356                         printk(KERN_ERR "olpc-dcon:  couldn't enable scanline interrupt!\n");
 357                 else {
 358                         /* Wait up to one second for the scanline interrupt */
 359                         wait_event_timeout(dcon_wait_queue, dcon_switched == 1, HZ);
 360                 }
 361
 362                 if (!dcon_switched)
 363                         printk(KERN_ERR "olpc-dcon:  Timeout entering CPU mode; expect a screen glitch.\n");
 364
 365                 /* Turn off the scanline interrupt */
 366                 if (dcon_write(DCON_REG_MODE, dcon_disp_mode))
 367                         printk(KERN_ERR "olpc-dcon:  couldn't disable scanline interrupt!\n");
 368
 369                 /*
 370                  * Ideally we'd like to disable interrupts here so that the
 371                  * fb unblanking and DCON turn on happen at a known time value;
 372                  * however, we can't do that right now with fb_blank
 373                  * messing with semaphores.
 374                  *
 375                  * For now, we just hope..
 376                  */
 377                 acquire_console_sem();
 378                 ignore_fb_events = 1;
 379                 if (fb_blank(fbinfo, FB_BLANK_UNBLANK)) {
 380                         ignore_fb_events = 0;
 381                         release_console_sem();
 382                         printk(KERN_ERR "olpc-dcon:  Failed to enter CPU mode\n");
 383                         dcon_pending = DCON_SOURCE_DCON;
 384                         return;
 385                 }
 386                 ignore_fb_events = 0;
 387                 release_console_sem();
 388
 389                 /* And turn off the DCON */
 390                 pdata->set_dconload(1);
 391                 getnstimeofday(&dcon_load_time);
 392
 393                 printk(KERN_INFO "olpc-dcon: The CPU has control\n");
 394                 break;
 395         case DCON_SOURCE_DCON:
 396         {
 397                 int t;
 398                 struct timespec delta_t;
 399
 400                 printk("dcon_source_switch to DCON\n");
 401
 402                 add_wait_queue(&dcon_wait_queue, &wait);
 403                 set_current_state(TASK_UNINTERRUPTIBLE);
 404
 405                 /* Clear DCONLOAD - this implies that the DCON is in control */
 406                 pdata->set_dconload(0);
 407                 getnstimeofday(&dcon_load_time);
 408
 409                 t = schedule_timeout(HZ/2);
 410                 remove_wait_queue(&dcon_wait_queue, &wait);
 411                 set_current_state(TASK_RUNNING);
 412
 413                 if (!dcon_switched) {
 414                         printk(KERN_ERR "olpc-dcon: Timeout entering DCON mode; expect a screen glitch.\n");
 415                 } else {
 416                         /* sometimes the DCON doesn't follow its own rules,
 417                          * and doesn't wait for two vsync pulses before
 418                          * ack'ing the frame load with an IRQ.  the result
 419                          * is that the display shows the *previously*
 420                          * loaded frame.  we can detect this by looking at
 421                          * the time between asserting DCONLOAD and the IRQ --
 422                          * if it's less than 20msec, then the DCON couldn't
 423                          * have seen two VSYNC pulses.  in that case we
 424                          * deassert and reassert, and hope for the best.
 425                          * see http://dev.laptop.org/ticket/9664
 426                          */
 427                         delta_t = timespec_sub(dcon_irq_time, dcon_load_time);
 428                         if (dcon_switched && delta_t.tv_sec == 0 &&
 429                                         delta_t.tv_nsec < NSEC_PER_MSEC * 20) {
 430                                 printk(KERN_ERR "olpc-dcon: missed loading, retrying\n");
 431                                 pdata->set_dconload(1);
 432                                 mdelay(41);
 433                                 pdata->set_dconload(0);
 434                                 getnstimeofday(&dcon_load_time);
 435                                 mdelay(41);
 436                         }
 437                 }
 438
 439                 acquire_console_sem();
 440                 ignore_fb_events = 1;
 441                 if (fb_blank(fbinfo, FB_BLANK_POWERDOWN))
 442                         printk(KERN_ERR "olpc-dcon:  couldn't blank fb!\n");
 443                 ignore_fb_events = 0;
 444                 release_console_sem();
 445
 446                 printk(KERN_INFO "olpc-dcon: The DCON has control\n");
 447                 break;
 448         }
 449         default:
 450                 BUG();
 451         }
 452
 453         dcon_source = source;
 454 }
 455
 456 static DECLARE_WORK(dcon_work, dcon_source_switch);
 457
 458 static void dcon_set_source(int arg)
 459 {
 460         if (dcon_pending == arg)
 461                 return;
 462
 463         dcon_pending = arg;
 464
 465         if ((dcon_source != arg) && !work_pending(&dcon_work))
 466                 schedule_work(&dcon_work);
 467 }
 468
 469 static void dcon_set_source_sync(int arg)
 470 {
 471         dcon_set_source(arg);
 472         flush_scheduled_work();
 473 }
 474
 475 static int dconbl_set(struct backlight_device *dev) {
 476
 477         int level = dev->props.brightness;
 478
 479         if (dev->props.power != FB_BLANK_UNBLANK)
 480                 level = 0;
 481
 482         dcon_set_backlight(level);
 483         return 0;
 484 }
 485
 486 static int dconbl_get(struct backlight_device *dev) {
 487         return dcon_get_backlight();
 488 }
 489
 490 static ssize_t dcon_mode_show(struct device *dev,
 491         struct device_attribute *attr, char *buf)
 492 {
 493         return sprintf(buf, "%4.4X\n", dcon_disp_mode);
 494 }
 495
 496 static ssize_t dcon_sleep_show(struct device *dev,
 497         struct device_attribute *attr, char *buf)
 498 {
 499
 500         return sprintf(buf, "%d\n", dcon_sleep_val);
 501 }
 502
 503 static ssize_t dcon_freeze_show(struct device *dev,
 504         struct device_attribute *attr, char *buf)
 505 {
 506         return sprintf(buf, "%d\n", dcon_source == DCON_SOURCE_DCON ? 1 : 0);
 507 }
 508
 509 static ssize_t dcon_output_show(struct device *dev,
 510         struct device_attribute *attr, char *buf)
 511 {
 512         return sprintf(buf, "%d\n", dcon_output);
 513 }
 514
 515 static ssize_t dcon_resumeline_show(struct device *dev,
 516         struct device_attribute *attr, char *buf)
 517 {
 518         return sprintf(buf, "%d\n", resumeline);
 519 }
 520
 521 static int _strtoul(const char *buf, int len, unsigned int *val)
 522 {
 523
 524         char *endp;
 525         unsigned int output = simple_strtoul(buf, &endp, 0);
 526         int size = endp - buf;
 527
 528         if (*endp && isspace(*endp))
 529                 size++;
 530
 531         if (size != len)
 532                 return -EINVAL;
 533
 534         *val = output;
 535         return 0;
 536 }
 537
 538 static ssize_t dcon_output_store(struct device *dev,
 539         struct device_attribute *attr, const char *buf, size_t count)
 540 {
 541         int output;
 542         int rc = -EINVAL;
 543
 544         if (_strtoul(buf, count, &output))
 545                 return -EINVAL;
 546
 547         if (output == DCON_OUTPUT_COLOR || output == DCON_OUTPUT_MONO) {
 548                 dcon_set_output(output);
 549                 rc = count;
 550         }
 551
 552         return rc;
 553 }
 554
 555 static ssize_t dcon_freeze_store(struct device *dev,
 556         struct device_attribute *attr, const char *buf, size_t count)
 557 {
 558         int output;
 559
 560         if (_strtoul(buf, count, &output))
 561                 return -EINVAL;
 562
 563         printk("dcon_freeze_store: %d\n", output);
 564
 565         switch (output) {
 566         case 0:
 567                 dcon_set_source(DCON_SOURCE_CPU);
 568                 break;
 569         case 1:
 570                 dcon_set_source_sync(DCON_SOURCE_DCON);
 571                 break;
 572         case 2:  // normally unused
 573                 dcon_set_source(DCON_SOURCE_DCON);
 574                 break;
 575         default:
 576                 return -EINVAL;
 577         }
 578
 579         return count;
 580 }
 581
 582 static ssize_t dcon_resumeline_store(struct device *dev,
 583         struct device_attribute *attr, const char *buf, size_t count)
 584 {
 585         int rl;
 586         int rc = -EINVAL;
 587
 588         if (_strtoul(buf, count, &rl))
 589                 return rc;
 590
 591         resumeline = rl;
 592         dcon_write(DCON_REG_SCAN_INT, resumeline);
 593         rc = count;
 594
 595         return rc;
 596 }
 597
 598 static ssize_t dcon_sleep_store(struct device *dev,
 599         struct device_attribute *attr, const char *buf, size_t count)
 600 {
 601         int output;
 602
 603         if (_strtoul(buf, count, &output))
 604                 return -EINVAL;
 605
 606         dcon_sleep(output ? DCON_SLEEP : DCON_ACTIVE);
 607         return count;
 608 }
 609
 610 static struct device_attribute dcon_device_files[] = {
 611         __ATTR(mode, 0444, dcon_mode_show, NULL),
 612         __ATTR(sleep, 0644, dcon_sleep_show, dcon_sleep_store),
 613         __ATTR(freeze, 0644, dcon_freeze_show, dcon_freeze_store),
 614         __ATTR(output, 0644, dcon_output_show, dcon_output_store),
 615         __ATTR(resumeline, 0644, dcon_resumeline_show, dcon_resumeline_store),
 616 };
 617
 618 static const struct backlight_ops dcon_bl_ops = {
 619         .get_brightness = dconbl_get,
 620         .update_status = dconbl_set
 621 };
 622
 623
 624 static int dcon_reboot_notify(struct notifier_block *nb, unsigned long foo, void *bar)
 625 {
 626         if (dcon_client == NULL)
 627                 return 0;
 628
 629         /* Turn off the DCON. Entirely. */
 630         dcon_write(DCON_REG_MODE, 0x39);
 631         dcon_write(DCON_REG_MODE, 0x32);
 632         return 0;
 633 }
 634
 635 static struct notifier_block dcon_nb = {
 636         .notifier_call = dcon_reboot_notify,
 637         .priority = -1,
 638 };
 639
 640 static int unfreeze_on_panic(struct notifier_block *nb, unsigned long e, void *p)
 641 {
 642         pdata->set_dconload(1);
 643         return NOTIFY_DONE;
 644 }
 645
 646 static struct notifier_block dcon_panic_nb = {
 647         .notifier_call = unfreeze_on_panic,
 648 };
 649
 650 /*
 651  * When the framebuffer sleeps due to external sources (e.g. user idle), power
 652  * down the DCON as well.  Power it back up when the fb comes back to life.
 653  */
 654 static int fb_notifier_callback(struct notifier_block *self, unsigned long event, void *data)
 655 {
 656         struct fb_event *evdata = data;
 657         int *blank = (int *) evdata->data;
 658         if (((event != FB_EVENT_BLANK) && (event != FB_EVENT_CONBLANK)) ||
 659                         ignore_fb_events)
 660                 return 0;
 661         dcon_sleep((*blank) ? DCON_SLEEP : DCON_ACTIVE);
 662         return 0;
 663 }
 664
 665 static struct notifier_block fb_nb = {
 666         .notifier_call = fb_notifier_callback,
 667 };
 668
 669 static int dcon_detect(struct i2c_client *client, struct i2c_board_info *info)
 670 {
 671         strlcpy(info->type, "olpc_dcon", I2C_NAME_SIZE);
 672
 673         return 0;
 674 }
 675
 676 static int dcon_probe(struct i2c_client *client, const struct i2c_device_id *id)
 677 {
 678         int rc, i;
 679
 680         if (num_registered_fb >= 1)
 681                 fbinfo = registered_fb[0];
 682
 683         rc = dcon_hw_init(client, 1);
 684         if (rc)
 685                 goto einit;
 686
 687         /* Add the DCON device */
 688
 689         dcon_device = platform_device_alloc("dcon", -1);
 690
 691         if (dcon_device == NULL) {
 692                 printk("dcon:  Unable to create the DCON device\n");
 693                 rc = -ENOMEM;
 694                 goto eirq;
 695         }
 696         /* Place holder...*/
 697         i2c_set_clientdata(client, dcon_device);
 698
 699         if ((rc = platform_device_add(dcon_device))) {
 700                 printk("dcon:  Unable to add the DCON device\n");
 701                 goto edev;
 702         }
 703
 704         for(i = 0; i < ARRAY_SIZE(dcon_device_files); i++)
 705                 device_create_file(&dcon_device->dev, &dcon_device_files[i]);
 706
 707         /* Add the backlight device for the DCON */
 708
 709         dcon_client = client;
 710
 711         dcon_bl_dev = backlight_device_register("dcon-bl", &dcon_device->dev,
 712                 NULL, &dcon_bl_ops, NULL);
 713
 714         if (IS_ERR(dcon_bl_dev)) {
 715                 printk("Could not register the backlight device for the DCON (%ld)\n", PTR_ERR(dcon_bl_dev));
 716                 dcon_bl_dev = NULL;
 717         }
 718         else {
 719                 dcon_bl_dev->props.max_brightness = 15;
 720                 dcon_bl_dev->props.power = FB_BLANK_UNBLANK;
 721                 dcon_bl_dev->props.brightness = dcon_get_backlight();
 722
 723                 backlight_update_status(dcon_bl_dev);
 724         }
 725
 726         register_reboot_notifier(&dcon_nb);
 727         atomic_notifier_chain_register(&panic_notifier_list, &dcon_panic_nb);
 728         fb_register_client(&fb_nb);
 729
 730         return 0;
 731
 732  edev:
 733         platform_device_unregister(dcon_device);
 734         dcon_device = NULL;
 735  eirq:
 736         free_irq(DCON_IRQ, &dcon_driver);
 737  einit:
 738         return rc;
 739 }
 740
 741 static int dcon_remove(struct i2c_client *client)
 742 {
 743         dcon_client = NULL;
 744
 745         fb_unregister_client(&fb_nb);
 746         unregister_reboot_notifier(&dcon_nb);
 747         atomic_notifier_chain_unregister(&panic_notifier_list, &dcon_panic_nb);
 748
 749         free_irq(DCON_IRQ, &dcon_driver);
 750
 751         if (dcon_bl_dev != NULL)
 752                 backlight_device_unregister(dcon_bl_dev);
 753
 754         if (dcon_device != NULL)
 755                 platform_device_unregister(dcon_device);
 756         cancel_work_sync(&dcon_work);
 757
 758         return 0;
 759 }
 760
 761 #ifdef CONFIG_PM
 762 static int dcon_suspend(struct i2c_client *client, pm_message_t state)
 763 {
 764         if (dcon_sleep_val == DCON_ACTIVE) {
 765                 /* Set up the DCON to have the source */
 766                 dcon_set_source_sync(DCON_SOURCE_DCON);
 767         }
 768
 769         return 0;
 770 }
 771
 772 static int dcon_resume(struct i2c_client *client)
 773 {
 774         if (dcon_sleep_val == DCON_ACTIVE) {
 775                 dcon_bus_stabilize(client, 0);
 776                 dcon_set_source(DCON_SOURCE_CPU);
 777         }
 778
 779         return 0;
 780 }
 781
 782 #endif
 783
 784
 785 static irqreturn_t dcon_interrupt(int irq, void *id)
 786 {
 787         int status = pdata->read_status();
 788
 789         if (status == -1)
 790                 return IRQ_NONE;
 791
 792         switch (status & 3) {
 793         case 3:
 794                 printk(KERN_DEBUG "olpc-dcon: DCONLOAD_MISSED interrupt\n");
 795                 break;
 796
 797         case 2: /* switch to DCON mode */
 798         case 1: /* switch to CPU mode */
 799                 dcon_switched = 1;
 800                 getnstimeofday(&dcon_irq_time);
 801                 wake_up(&dcon_wait_queue);
 802                 break;
 803
 804         case 0:
 805                 /* workaround resume case:  the DCON (on 1.5) doesn't
 806                  * ever assert status 0x01 when switching to CPU mode
 807                  * during resume.  this is because DCONLOAD is de-asserted
 808                  * _immediately_ upon exiting S3, so the actual release
 809                  * of the DCON happened long before this point.
 810                  * see http://dev.laptop.org/ticket/9869
 811                  */
 812                 if (dcon_source != dcon_pending && !dcon_switched) {
 813                         dcon_switched = 1;
 814                         getnstimeofday(&dcon_irq_time);
 815                         wake_up(&dcon_wait_queue);
 816                         printk(KERN_DEBUG "olpc-dcon: switching w/ status 0/0\n");
 817                 } else {
 818                         printk(KERN_DEBUG "olpc-dcon: scanline interrupt w/CPU\n");
 819                 }
 820         }
 821
 822         return IRQ_HANDLED;
 823 }
 824
 825 static struct i2c_device_id dcon_idtable[] = {
 826         { "olpc_dcon",  0 },
 827         { }
 828 };
 829
 830 MODULE_DEVICE_TABLE(i2c, dcon_idtable);
 831
 832 static struct i2c_driver dcon_driver = {
 833         .driver = {
 834                 .name   = "olpc_dcon",
 835         },
 836         .class = I2C_CLASS_DDC | I2C_CLASS_HWMON,
 837         .id_table = dcon_idtable,
 838         .probe = dcon_probe,
 839         .remove = __devexit_p(dcon_remove),
 840         .detect = dcon_detect,
 841         .address_list = normal_i2c,
 842 #ifdef CONFIG_PM
 843         .suspend = dcon_suspend,
 844         .resume = dcon_resume,
 845 #endif
 846 };
 847
 848 #include "olpc_dcon_xo_1.c"
 849
 850 static int __init olpc_dcon_init(void)
 851 {
 852         pdata = &dcon_pdata_xo_1;
 853
 854         i2c_add_driver(&dcon_driver);
 855         return 0;
 856 }
 857
 858 static void __exit olpc_dcon_exit(void)
 859 {
 860         i2c_del_driver(&dcon_driver);
 861 }
 862
 863 module_init(olpc_dcon_init);
 864 module_exit(olpc_dcon_exit);
 865
 866 MODULE_LICENSE("GPL");