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/i2c-id.h>
  21 #include <linux/pci.h>
  22 #include <linux/pci_ids.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/delay.h>
  25 #include <linux/backlight.h>
  26 #include <linux/device.h>
  27 #include <linux/notifier.h>
  28 #include <asm/uaccess.h>
  29 #include <linux/ctype.h>
  30 #include <linux/reboot.h>
  31 #include <linux/gpio.h>
  32 #include <asm/tsc.h>
  33 #include <asm/olpc.h>
  34
  35 #include "olpc_dcon.h"
  36
  37 /* Module definitions */
  38
  39 static int resumeline = 898;
  40 module_param(resumeline, int, 0444);
  41
  42 static int noinit;
  43 module_param(noinit, int, 0444);
  44
  45 /* Default off since it doesn't work on DCON ASIC in B-test OLPC board */
  46 static int useaa = 1;
  47 module_param(useaa, int, 0444);
  48
  49 struct dcon_platform_data {
  50         int (*init)(void);
  51         void (*bus_stabilize_wiggle)(void);
  52         void (*set_dconload)(int);
  53         int (*read_status)(void);
  54 };
  55
  56 static struct dcon_platform_data *pdata;
  57
  58 /* I2C structures */
  59
  60 static struct i2c_driver dcon_driver;
  61 static struct i2c_client *dcon_client;
  62
  63 /* Platform devices */
  64 static struct platform_device *dcon_device;
  65
  66 /* Backlight device */
  67 static struct backlight_device *dcon_bl_dev;
  68
  69 static struct fb_info *fbinfo;
  70
  71 /* set this to 1 while controlling fb blank state from this driver */
  72 static int ignore_fb_events = 0;
  73
  74 /* Current source, initialized at probe time */
  75 static int dcon_source;
  76
  77 /* Desired source */
  78 static int dcon_pending;
  79
  80 /* Current output type */
  81 static int dcon_output = DCON_OUTPUT_COLOR;
  82
  83 /* Current sleep status (not yet implemented) */
  84 static int dcon_sleep_val = DCON_ACTIVE;
  85
  86 /* Shadow register for the DCON_REG_MODE register */
  87 static unsigned short dcon_disp_mode;
  88
  89 /* Variables used during switches */
  90 static int dcon_switched;
  91 static struct timespec dcon_irq_time;
  92 static struct timespec dcon_load_time;
  93
  94 static DECLARE_WAIT_QUEUE_HEAD(dcon_wait_queue);
  95
  96 static unsigned short normal_i2c[] = { 0x0d, I2C_CLIENT_END };
  97
  98 #define dcon_write(reg,val) i2c_smbus_write_word_data(dcon_client,reg,val)
  99 #define dcon_read(reg) i2c_smbus_read_word_data(dcon_client,reg)
 100
 101 /* The current backlight value - this saves us some smbus traffic */
 102 static int bl_val = -1;
 103
 104 /* ===== API functions - these are called by a variety of users ==== */
 105
 106 static int dcon_hw_init(struct i2c_client *client, int is_init)
 107 {
 108         uint16_t ver;
 109         int rc = 0;
 110
 111         ver = i2c_smbus_read_word_data(client, DCON_REG_ID);
 112         if ((ver >> 8) != 0xDC) {
 113                 printk(KERN_ERR "olpc-dcon:  DCON ID not 0xDCxx: 0x%04x "
 114                                 "instead.\n", ver);
 115                 rc = -ENXIO;
 116                 goto err;
 117         }
 118
 119         if (is_init) {
 120                 printk(KERN_INFO "olpc-dcon:  Discovered DCON version %x\n",
 121                                 ver & 0xFF);
 122                 if ((rc = pdata->init()) != 0) {
 123                         printk(KERN_ERR "olpc-dcon:  Unable to init.\n");
 124                         goto err;
 125                 }
 126         }
 127
 128         if (ver < 0xdc02 && !noinit) {
 129                 /* Initialize the DCON registers */
 130
 131                 /* Start with work-arounds for DCON ASIC */
 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, 0x4b, 0x00cc);
 135                 i2c_smbus_write_word_data(client, 0x0b, 0x007a);
 136                 i2c_smbus_write_word_data(client, 0x36, 0x025c);
 137                 i2c_smbus_write_word_data(client, 0x37, 0x025e);
 138
 139                 /* Initialise SDRAM */
 140
 141                 i2c_smbus_write_word_data(client, 0x3b, 0x002b);
 142                 i2c_smbus_write_word_data(client, 0x41, 0x0101);
 143                 i2c_smbus_write_word_data(client, 0x42, 0x0101);
 144         }
 145         else if (!noinit) {
 146                 /* SDRAM setup/hold time */
 147                 i2c_smbus_write_word_data(client, 0x3a, 0xc040);
 148                 i2c_smbus_write_word_data(client, 0x41, 0x0000);
 149                 i2c_smbus_write_word_data(client, 0x41, 0x0101);
 150                 i2c_smbus_write_word_data(client, 0x42, 0x0101);
 151         }
 152
 153         /* Colour swizzle, AA, no passthrough, backlight */
 154         if (is_init) {
 155                 dcon_disp_mode = MODE_PASSTHRU | MODE_BL_ENABLE | MODE_CSWIZZLE;
 156                 if (useaa)
 157                         dcon_disp_mode |= MODE_COL_AA;
 158         }
 159         i2c_smbus_write_word_data(client, DCON_REG_MODE, dcon_disp_mode);
 160
 161
 162         /* Set the scanline to interrupt on during resume */
 163         i2c_smbus_write_word_data(client, DCON_REG_SCAN_INT, resumeline);
 164
 165 err:
 166         return rc;
 167 }
 168
 169 /*
 170  * The smbus doesn't always come back due to what is believed to be
 171  * hardware (power rail) bugs.  For older models where this is known to
 172  * occur, our solution is to attempt to wait for the bus to stabilize;
 173  * if it doesn't happen, cut power to the dcon, repower it, and wait
 174  * for the bus to stabilize.  Rinse, repeat until we have a working
 175  * smbus.  For newer models, we simply BUG(); we want to know if this
 176  * still happens despite the power fixes that have been made!
 177  */
 178 static int dcon_bus_stabilize(struct i2c_client *client, int is_powered_down)
 179 {
 180         unsigned long timeout;
 181         int x;
 182
 183 power_up:
 184         if (is_powered_down) {
 185                 x = 1;
 186                 if ((x = olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0))) {
 187                         printk(KERN_WARNING "olpc-dcon:  unable to force dcon "
 188                                         "to power up: %d!\n", x);
 189                         return x;
 190                 }
 191                 msleep(10); /* we'll be conservative */
 192         }
 193
 194         pdata->bus_stabilize_wiggle();
 195
 196         for (x = -1, timeout = 50; timeout && x < 0; timeout--) {
 197                 msleep(1);
 198                 x = dcon_read(DCON_REG_ID);
 199         }
 200         if (x < 0) {
 201                 printk(KERN_ERR "olpc-dcon:  unable to stabilize dcon's "
 202                                 "smbus, reasserting power and praying.\n");
 203                 BUG_ON(olpc_board_at_least(olpc_board(0xc2)));
 204                 x = 0;
 205                 olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0);
 206                 msleep(100);
 207                 is_powered_down = 1;
 208                 goto power_up;  /* argh, stupid hardware.. */
 209         }
 210
 211         if (is_powered_down)
 212                 return dcon_hw_init(client, 0);
 213         return 0;
 214 }
 215
 216 static int dcon_get_backlight(void)
 217 {
 218         if (dcon_client == NULL)
 219                 return 0;
 220
 221         if (bl_val == -1)
 222                 bl_val = dcon_read(DCON_REG_BRIGHT) & 0x0F;
 223
 224         return bl_val;
 225 }
 226
 227
 228 static void dcon_set_backlight_hw(int level)
 229 {
 230         bl_val = level & 0x0F;
 231         dcon_write(DCON_REG_BRIGHT, bl_val);
 232
 233         /* Purposely turn off the backlight when we go to level 0 */
 234         if (bl_val == 0) {
 235                 dcon_disp_mode &= ~MODE_BL_ENABLE;
 236                 dcon_write(DCON_REG_MODE, dcon_disp_mode);
 237         } else if (!(dcon_disp_mode & MODE_BL_ENABLE)) {
 238                 dcon_disp_mode |= MODE_BL_ENABLE;
 239                 dcon_write(DCON_REG_MODE, dcon_disp_mode);
 240         }
 241 }
 242
 243 static void dcon_set_backlight(int level)
 244 {
 245         if (dcon_client == NULL)
 246                 return;
 247
 248         if (bl_val == (level & 0x0F))
 249                 return;
 250
 251         dcon_set_backlight_hw(level);
 252 }
 253
 254 /* Set the output type to either color or mono */
 255
 256 static int dcon_set_output(int arg)
 257 {
 258         if (dcon_output == arg)
 259                 return 0;
 260
 261         dcon_output = arg;
 262
 263         if (arg == DCON_OUTPUT_MONO) {
 264                 dcon_disp_mode &= ~(MODE_CSWIZZLE | MODE_COL_AA);
 265                 dcon_disp_mode |= MODE_MONO_LUMA;
 266         }
 267         else {
 268                 dcon_disp_mode &= ~(MODE_MONO_LUMA);
 269                 dcon_disp_mode |= MODE_CSWIZZLE;
 270                 if (useaa)
 271                         dcon_disp_mode |= MODE_COL_AA;
 272         }
 273
 274         dcon_write(DCON_REG_MODE, dcon_disp_mode);
 275         return 0;
 276 }
 277
 278 /* For now, this will be really stupid - we need to address how
 279  * DCONLOAD works in a sleep and account for it accordingly
 280  */
 281
 282 static void dcon_sleep(int state)
 283 {
 284         int x;
 285
 286         /* Turn off the backlight and put the DCON to sleep */
 287
 288         if (state == dcon_sleep_val)
 289                 return;
 290
 291         if (!olpc_board_at_least(olpc_board(0xc2)))
 292                 return;
 293
 294         if (state == DCON_SLEEP) {
 295                 x = 0;
 296                 if ((x = olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0)))
 297                         printk(KERN_WARNING "olpc-dcon:  unable to force dcon "
 298                                         "to power down: %d!\n", x);
 299                 else
 300                         dcon_sleep_val = state;
 301         }
 302         else {
 303                 /* Only re-enable the backlight if the backlight value is set */
 304                 if (bl_val != 0)
 305                         dcon_disp_mode |= MODE_BL_ENABLE;
 306
 307                 if ((x=dcon_bus_stabilize(dcon_client, 1)))
 308                         printk(KERN_WARNING "olpc-dcon:  unable to reinit dcon"
 309                                         " hardware: %d!\n", x);
 310                 else
 311                         dcon_sleep_val = state;
 312
 313                 /* Restore backlight */
 314                 dcon_set_backlight_hw(bl_val);
 315         }
 316
 317         /* We should turn off some stuff in the framebuffer - but what? */
 318 }
 319
 320 /* the DCON seems to get confused if we change DCONLOAD too
 321  * frequently -- i.e., approximately faster than frame time.
 322  * normally we don't change it this fast, so in general we won't
 323  * delay here.
 324  */
 325 void dcon_load_holdoff(void)
 326 {
 327         struct timespec delta_t, now;
 328         while(1) {
 329                 getnstimeofday(&now);
 330                 delta_t = timespec_sub(now, dcon_load_time);
 331                 if (delta_t.tv_sec != 0 ||
 332                         delta_t.tv_nsec > NSEC_PER_MSEC * 20) {
 333                         break;
 334                 }
 335                 mdelay(4);
 336         }
 337 }
 338 /* Set the source of the display (CPU or DCON) */
 339
 340 static void dcon_source_switch(struct work_struct *work)
 341 {
 342         DECLARE_WAITQUEUE(wait, current);
 343         int source = dcon_pending;
 344
 345         if (dcon_source == source)
 346                 return;
 347
 348         dcon_load_holdoff();
 349
 350         dcon_switched = 0;
 351
 352         switch (source) {
 353         case DCON_SOURCE_CPU:
 354                 printk("dcon_source_switch to CPU\n");
 355                 /* Enable the scanline interrupt bit */
 356                 if (dcon_write(DCON_REG_MODE, dcon_disp_mode | MODE_SCAN_INT))
 357                         printk(KERN_ERR "olpc-dcon:  couldn't enable scanline interrupt!\n");
 358                 else {
 359                         /* Wait up to one second for the scanline interrupt */
 360                         wait_event_timeout(dcon_wait_queue, dcon_switched == 1, HZ);
 361                 }
 362
 363                 if (!dcon_switched)
 364                         printk(KERN_ERR "olpc-dcon:  Timeout entering CPU mode; expect a screen glitch.\n");
 365
 366                 /* Turn off the scanline interrupt */
 367                 if (dcon_write(DCON_REG_MODE, dcon_disp_mode))
 368                         printk(KERN_ERR "olpc-dcon:  couldn't disable scanline interrupt!\n");
 369
 370                 /*
 371                  * Ideally we'd like to disable interrupts here so that the
 372                  * fb unblanking and DCON turn on happen at a known time value;
 373                  * however, we can't do that right now with fb_blank
 374                  * messing with semaphores.
 375                  *
 376                  * For now, we just hope..
 377                  */
 378                 acquire_console_sem();
 379                 ignore_fb_events = 1;
 380                 if (fb_blank(fbinfo, FB_BLANK_UNBLANK)) {
 381                         ignore_fb_events = 0;
 382                         release_console_sem();
 383                         printk(KERN_ERR "olpc-dcon:  Failed to enter CPU mode\n");
 384                         dcon_pending = DCON_SOURCE_DCON;
 385                         return;
 386                 }
 387                 ignore_fb_events = 0;
 388                 release_console_sem();
 389
 390                 /* And turn off the DCON */
 391                 pdata->set_dconload(1);
 392                 getnstimeofday(&dcon_load_time);
 393
 394                 printk(KERN_INFO "olpc-dcon: The CPU has control\n");
 395                 break;
 396         case DCON_SOURCE_DCON:
 397         {
 398                 int t;
 399                 struct timespec delta_t;
 400
 401                 printk("dcon_source_switch to DCON\n");
 402
 403                 add_wait_queue(&dcon_wait_queue, &wait);
 404                 set_current_state(TASK_UNINTERRUPTIBLE);
 405
 406                 /* Clear DCONLOAD - this implies that the DCON is in control */
 407                 pdata->set_dconload(0);
 408                 getnstimeofday(&dcon_load_time);
 409
 410                 t = schedule_timeout(HZ/2);
 411                 remove_wait_queue(&dcon_wait_queue, &wait);
 412                 set_current_state(TASK_RUNNING);
 413
 414                 if (!dcon_switched) {
 415                         printk(KERN_ERR "olpc-dcon: Timeout entering DCON mode; expect a screen glitch.\n");
 416                 } else {
 417                         /* sometimes the DCON doesn't follow its own rules,
 418                          * and doesn't wait for two vsync pulses before
 419                          * ack'ing the frame load with an IRQ.  the result
 420                          * is that the display shows the *previously*
 421                          * loaded frame.  we can detect this by looking at
 422                          * the time between asserting DCONLOAD and the IRQ --
 423                          * if it's less than 20msec, then the DCON couldn't
 424                          * have seen two VSYNC pulses.  in that case we
 425                          * deassert and reassert, and hope for the best.
 426                          * see http://dev.laptop.org/ticket/9664
 427                          */
 428                         delta_t = timespec_sub(dcon_irq_time, dcon_load_time);
 429                         if (dcon_switched && delta_t.tv_sec == 0 &&
 430                                         delta_t.tv_nsec < NSEC_PER_MSEC * 20) {
 431                                 printk(KERN_ERR "olpc-dcon: missed loading, retrying\n");
 432                                 pdata->set_dconload(1);
 433                                 mdelay(41);
 434                                 pdata->set_dconload(0);
 435                                 getnstimeofday(&dcon_load_time);
 436                                 mdelay(41);
 437                         }
 438                 }
 439
 440                 acquire_console_sem();
 441                 ignore_fb_events = 1;
 442                 if (fb_blank(fbinfo, FB_BLANK_POWERDOWN))
 443                         printk(KERN_ERR "olpc-dcon:  couldn't blank fb!\n");
 444                 ignore_fb_events = 0;
 445                 release_console_sem();
 446
 447                 printk(KERN_INFO "olpc-dcon: The DCON has control\n");
 448                 break;
 449         }
 450         default:
 451                 BUG();
 452         }
 453
 454         dcon_source = source;
 455 }
 456
 457 static DECLARE_WORK(dcon_work, dcon_source_switch);
 458
 459 static void dcon_set_source(int arg)
 460 {
 461         if (dcon_pending == arg)
 462                 return;
 463
 464         dcon_pending = arg;
 465
 466         if ((dcon_source != arg) && !work_pending(&dcon_work))
 467                 schedule_work(&dcon_work);
 468 }
 469
 470 static void dcon_set_source_sync(int arg)
 471 {
 472         dcon_set_source(arg);
 473         flush_scheduled_work();
 474 }
 475
 476 static int dconbl_set(struct backlight_device *dev) {
 477
 478         int level = dev->props.brightness;
 479
 480         if (dev->props.power != FB_BLANK_UNBLANK)
 481                 level = 0;
 482
 483         dcon_set_backlight(level);
 484         return 0;
 485 }
 486
 487 static int dconbl_get(struct backlight_device *dev) {
 488         return dcon_get_backlight();
 489 }
 490
 491 static ssize_t dcon_mode_show(struct device *dev,
 492         struct device_attribute *attr, char *buf)
 493 {
 494         return sprintf(buf, "%4.4X\n", dcon_disp_mode);
 495 }
 496
 497 static ssize_t dcon_sleep_show(struct device *dev,
 498         struct device_attribute *attr, char *buf)
 499 {
 500
 501         return sprintf(buf, "%d\n", dcon_sleep_val);
 502 }
 503
 504 static ssize_t dcon_freeze_show(struct device *dev,
 505         struct device_attribute *attr, char *buf)
 506 {
 507         return sprintf(buf, "%d\n", dcon_source == DCON_SOURCE_DCON ? 1 : 0);
 508 }
 509
 510 static ssize_t dcon_output_show(struct device *dev,
 511         struct device_attribute *attr, char *buf)
 512 {
 513         return sprintf(buf, "%d\n", dcon_output);
 514 }
 515
 516 static ssize_t dcon_resumeline_show(struct device *dev,
 517         struct device_attribute *attr, char *buf)
 518 {
 519         return sprintf(buf, "%d\n", resumeline);
 520 }
 521
 522 static int _strtoul(const char *buf, int len, unsigned int *val)
 523 {
 524
 525         char *endp;
 526         unsigned int output = simple_strtoul(buf, &endp, 0);
 527         int size = endp - buf;
 528
 529         if (*endp && isspace(*endp))
 530                 size++;
 531
 532         if (size != len)
 533                 return -EINVAL;
 534
 535         *val = output;
 536         return 0;
 537 }
 538
 539 static ssize_t dcon_output_store(struct device *dev,
 540         struct device_attribute *attr, const char *buf, size_t count)
 541 {
 542         int output;
 543         int rc = -EINVAL;
 544
 545         if (_strtoul(buf, count, &output))
 546                 return -EINVAL;
 547
 548         if (output == DCON_OUTPUT_COLOR || output == DCON_OUTPUT_MONO) {
 549                 dcon_set_output(output);
 550                 rc = count;
 551         }
 552
 553         return rc;
 554 }
 555
 556 static ssize_t dcon_freeze_store(struct device *dev,
 557         struct device_attribute *attr, const char *buf, size_t count)
 558 {
 559         int output;
 560
 561         if (_strtoul(buf, count, &output))
 562                 return -EINVAL;
 563
 564         printk("dcon_freeze_store: %d\n", output);
 565
 566         switch (output) {
 567         case 0:
 568                 dcon_set_source(DCON_SOURCE_CPU);
 569                 break;
 570         case 1:
 571                 dcon_set_source_sync(DCON_SOURCE_DCON);
 572                 break;
 573         case 2:  // normally unused
 574                 dcon_set_source(DCON_SOURCE_DCON);
 575                 break;
 576         default:
 577                 return -EINVAL;
 578         }
 579
 580         return count;
 581 }
 582
 583 static ssize_t dcon_resumeline_store(struct device *dev,
 584         struct device_attribute *attr, const char *buf, size_t count)
 585 {
 586         int rl;
 587         int rc = -EINVAL;
 588
 589         if (_strtoul(buf, count, &rl))
 590                 return rc;
 591
 592         resumeline = rl;
 593         dcon_write(DCON_REG_SCAN_INT, resumeline);
 594         rc = count;
 595
 596         return rc;
 597 }
 598
 599 static ssize_t dcon_sleep_store(struct device *dev,
 600         struct device_attribute *attr, const char *buf, size_t count)
 601 {
 602         int output;
 603
 604         if (_strtoul(buf, count, &output))
 605                 return -EINVAL;
 606
 607         dcon_sleep(output ? DCON_SLEEP : DCON_ACTIVE);
 608         return count;
 609 }
 610
 611 static struct device_attribute dcon_device_files[] = {
 612         __ATTR(mode, 0444, dcon_mode_show, NULL),
 613         __ATTR(sleep, 0644, dcon_sleep_show, dcon_sleep_store),
 614         __ATTR(freeze, 0644, dcon_freeze_show, dcon_freeze_store),
 615         __ATTR(output, 0644, dcon_output_show, dcon_output_store),
 616         __ATTR(resumeline, 0644, dcon_resumeline_show, dcon_resumeline_store),
 617 };
 618
 619 static struct backlight_ops dcon_bl_ops = {
 620         .get_brightness = dconbl_get,
 621         .update_status = dconbl_set
 622 };
 623
 624
 625 static int dcon_reboot_notify(struct notifier_block *nb, unsigned long foo, void *bar)
 626 {
 627         if (dcon_client == NULL)
 628                 return 0;
 629
 630         /* Turn off the DCON. Entirely. */
 631         dcon_write(DCON_REG_MODE, 0x39);
 632         dcon_write(DCON_REG_MODE, 0x32);
 633         return 0;
 634 }
 635
 636 static struct notifier_block dcon_nb = {
 637         .notifier_call = dcon_reboot_notify,
 638         .priority = -1,
 639 };
 640
 641 static int unfreeze_on_panic(struct notifier_block *nb, unsigned long e, void *p)
 642 {
 643         pdata->set_dconload(1);
 644         return NOTIFY_DONE;
 645 }
 646
 647 static struct notifier_block dcon_panic_nb = {
 648         .notifier_call = unfreeze_on_panic,
 649 };
 650
 651 /*
 652  * When the framebuffer sleeps due to external sources (e.g. user idle), power
 653  * down the DCON as well.  Power it back up when the fb comes back to life.
 654  */
 655 static int fb_notifier_callback(struct notifier_block *self, unsigned long event, void *data)
 656 {
 657         struct fb_event *evdata = data;
 658         int *blank = (int *) evdata->data;
 659         if (((event != FB_EVENT_BLANK) && (event != FB_EVENT_CONBLANK)) ||
 660                         ignore_fb_events)
 661                 return 0;
 662         dcon_sleep((*blank) ? DCON_SLEEP : DCON_ACTIVE);
 663         return 0;
 664 }
 665
 666 static struct notifier_block fb_nb = {
 667         .notifier_call = fb_notifier_callback,
 668 };
 669
 670 static int dcon_detect(struct i2c_client *client, struct i2c_board_info *info)
 671 {
 672         strlcpy(info->type, "olpc_dcon", I2C_NAME_SIZE);
 673
 674         return 0;
 675 }
 676
 677 static int dcon_probe(struct i2c_client *client, const struct i2c_device_id *id)
 678 {
 679         int rc, i;
 680
 681         if (num_registered_fb >= 1)
 682                 fbinfo = registered_fb[0];
 683
 684         rc = dcon_hw_init(client, 1);
 685         if (rc)
 686                 goto einit;
 687
 688         /* Add the DCON device */
 689
 690         dcon_device = platform_device_alloc("dcon", -1);
 691
 692         if (dcon_device == NULL) {
 693                 printk("dcon:  Unable to create the DCON device\n");
 694                 rc = -ENOMEM;
 695                 goto eirq;
 696         }
 697         /* Place holder...*/
 698         i2c_set_clientdata(client, dcon_device);
 699
 700         if ((rc = platform_device_add(dcon_device))) {
 701                 printk("dcon:  Unable to add the DCON device\n");
 702                 goto edev;
 703         }
 704
 705         for(i = 0; i < ARRAY_SIZE(dcon_device_files); i++)
 706                 device_create_file(&dcon_device->dev, &dcon_device_files[i]);
 707
 708         /* Add the backlight device for the DCON */
 709
 710         dcon_client = client;
 711
 712         dcon_bl_dev = backlight_device_register("dcon-bl", &dcon_device->dev,
 713                 NULL, &dcon_bl_ops, NULL);
 714
 715         if (IS_ERR(dcon_bl_dev)) {
 716                 printk("Could not register the backlight device for the DCON (%ld)\n", PTR_ERR(dcon_bl_dev));
 717                 dcon_bl_dev = NULL;
 718         }
 719         else {
 720                 dcon_bl_dev->props.max_brightness = 15;
 721                 dcon_bl_dev->props.power = FB_BLANK_UNBLANK;
 722                 dcon_bl_dev->props.brightness = dcon_get_backlight();
 723
 724                 backlight_update_status(dcon_bl_dev);
 725         }
 726
 727         register_reboot_notifier(&dcon_nb);
 728         atomic_notifier_chain_register(&panic_notifier_list, &dcon_panic_nb);
 729         fb_register_client(&fb_nb);
 730
 731         return 0;
 732
 733  edev:
 734         platform_device_unregister(dcon_device);
 735         dcon_device = NULL;
 736         i2c_set_clientdata(client, NULL);
 737  eirq:
 738         free_irq(DCON_IRQ, &dcon_driver);
 739  einit:
 740         return rc;
 741 }
 742
 743 static int dcon_remove(struct i2c_client *client)
 744 {
 745         dcon_client = NULL;
 746
 747         fb_unregister_client(&fb_nb);
 748         unregister_reboot_notifier(&dcon_nb);
 749         atomic_notifier_chain_unregister(&panic_notifier_list, &dcon_panic_nb);
 750
 751         free_irq(DCON_IRQ, &dcon_driver);
 752
 753         if (dcon_bl_dev != NULL)
 754                 backlight_device_unregister(dcon_bl_dev);
 755
 756         if (dcon_device != NULL)
 757                 platform_device_unregister(dcon_device);
 758         cancel_work_sync(&dcon_work);
 759
 760         i2c_set_clientdata(client, NULL);
 761
 762         return 0;
 763 }
 764
 765 #ifdef CONFIG_PM
 766 static int dcon_suspend(struct i2c_client *client, pm_message_t state)
 767 {
 768         if (dcon_sleep_val == DCON_ACTIVE) {
 769                 /* Set up the DCON to have the source */
 770                 dcon_set_source_sync(DCON_SOURCE_DCON);
 771         }
 772
 773         return 0;
 774 }
 775
 776 static int dcon_resume(struct i2c_client *client)
 777 {
 778         if (dcon_sleep_val == DCON_ACTIVE) {
 779                 dcon_bus_stabilize(client, 0);
 780                 dcon_set_source(DCON_SOURCE_CPU);
 781         }
 782
 783         return 0;
 784 }
 785
 786 #endif
 787
 788
 789 static irqreturn_t dcon_interrupt(int irq, void *id)
 790 {
 791         int status = pdata->read_status();
 792
 793         if (status == -1)
 794                 return IRQ_NONE;
 795
 796         switch (status & 3) {
 797         case 3:
 798                 printk(KERN_DEBUG "olpc-dcon: DCONLOAD_MISSED interrupt\n");
 799                 break;
 800
 801         case 2: /* switch to DCON mode */
 802         case 1: /* switch to CPU mode */
 803                 dcon_switched = 1;
 804                 getnstimeofday(&dcon_irq_time);
 805                 wake_up(&dcon_wait_queue);
 806                 break;
 807
 808         case 0:
 809                 /* workaround resume case:  the DCON (on 1.5) doesn't
 810                  * ever assert status 0x01 when switching to CPU mode
 811                  * during resume.  this is because DCONLOAD is de-asserted
 812                  * _immediately_ upon exiting S3, so the actual release
 813                  * of the DCON happened long before this point.
 814                  * see http://dev.laptop.org/ticket/9869
 815                  */
 816                 if (dcon_source != dcon_pending && !dcon_switched) {
 817                         dcon_switched = 1;
 818                         getnstimeofday(&dcon_irq_time);
 819                         wake_up(&dcon_wait_queue);
 820                         printk(KERN_DEBUG "olpc-dcon: switching w/ status 0/0\n");
 821                 } else {
 822                         printk(KERN_DEBUG "olpc-dcon: scanline interrupt w/CPU\n");
 823                 }
 824         }
 825
 826         return IRQ_HANDLED;
 827 }
 828
 829 static struct i2c_device_id dcon_idtable[] = {
 830         { "olpc_dcon",  0 },
 831         { }
 832 };
 833
 834 MODULE_DEVICE_TABLE(i2c, dcon_idtable);
 835
 836 static struct i2c_driver dcon_driver = {
 837         .driver = {
 838                 .name   = "olpc_dcon",
 839         },
 840         .class = I2C_CLASS_DDC | I2C_CLASS_HWMON,
 841         .id_table = dcon_idtable,
 842         .probe = dcon_probe,
 843         .remove = __devexit_p(dcon_remove),
 844         .detect = dcon_detect,
 845         .address_list = normal_i2c,
 846 #ifdef CONFIG_PM
 847         .suspend = dcon_suspend,
 848         .resume = dcon_resume,
 849 #endif
 850 };
 851
 852 #include "olpc_dcon_xo_1.c"
 853
 854 static int __init olpc_dcon_init(void)
 855 {
 856         pdata = &dcon_pdata_xo_1;
 857
 858         i2c_add_driver(&dcon_driver);
 859         return 0;
 860 }
 861
 862 static void __exit olpc_dcon_exit(void)
 863 {
 864         i2c_del_driver(&dcon_driver);
 865 }
 866
 867 module_init(olpc_dcon_init);
 868 module_exit(olpc_dcon_exit);
 869
 870 MODULE_LICENSE("GPL");