drivers/staging/olpc_dcon/olpc_dcon.c

   1 /*
   2  * Mainly by David Woodhouse, somewhat modified by Jordan Crouse
   3  *
   4  * Copyright © 2006-2007  Red Hat, Inc.
   5  * Copyright © 2006-2007  Advanced Micro Devices, Inc.
   6  * Copyright © 2009       VIA Technology, Inc.
   7  * Copyright (c) 2010  Andres Salomon <dilinger@queued.net>
   8  *
   9  * This program is free software.  You can redistribute it and/or
  10  * modify it under the terms of version 2 of the GNU General Public
  11  * License as published by the Free Software Foundation.
  12  */
  13
  14
  15 #include <linux/kernel.h>
  16 #include <linux/fb.h>
  17 #include <linux/console.h>
  18 #include <linux/i2c.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/pci.h>
  21 #include <linux/pci_ids.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/delay.h>
  24 #include <linux/backlight.h>
  25 #include <linux/device.h>
  26 #include <linux/notifier.h>
  27 #include <linux/uaccess.h>
  28 #include <linux/ctype.h>
  29 #include <linux/reboot.h>
  30 #include <asm/tsc.h>
  31 #include <asm/olpc.h>
  32
  33 #include "olpc_dcon.h"
  34
  35 /* Module definitions */
  36
  37 static int resumeline = 898;
  38 module_param(resumeline, int, 0444);
  39
  40 static int noinit;
  41 module_param(noinit, int, 0444);
  42
  43 /* Default off since it doesn't work on DCON ASIC in B-test OLPC board */
  44 static int useaa = 1;
  45 module_param(useaa, int, 0444);
  46
  47 struct dcon_platform_data {
  48         int (*init)(void);
  49         void (*bus_stabilize_wiggle)(void);
  50         void (*set_dconload)(int);
  51         u8 (*read_status)(void);
  52 };
  53
  54 static struct dcon_platform_data *pdata;
  55
  56 struct dcon_priv {
  57         struct i2c_client *client;
  58
  59         struct work_struct switch_source;
  60         struct notifier_block reboot_nb;
  61 };
  62
  63 /* I2C structures */
  64
  65 static struct i2c_driver dcon_driver;
  66
  67 /* Platform devices */
  68 static struct platform_device *dcon_device;
  69
  70 /* Backlight device */
  71 static struct backlight_device *dcon_bl_dev;
  72
  73 static struct fb_info *fbinfo;
  74
  75 /* set this to 1 while controlling fb blank state from this driver */
  76 static int ignore_fb_events = 0;
  77
  78 /* Current source, initialized at probe time */
  79 static int dcon_source;
  80
  81 /* Desired source */
  82 static int dcon_pending;
  83
  84 /* Current output type */
  85 static int dcon_output = DCON_OUTPUT_COLOR;
  86
  87 /* Current sleep status (not yet implemented) */
  88 static int dcon_sleep_val = DCON_ACTIVE;
  89
  90 /* Shadow register for the DCON_REG_MODE register */
  91 static unsigned short dcon_disp_mode;
  92
  93 /* Variables used during switches */
  94 static int dcon_switched;
  95 static struct timespec dcon_irq_time;
  96 static struct timespec dcon_load_time;
  97
  98 static DECLARE_WAIT_QUEUE_HEAD(dcon_wait_queue);
  99
 100 static unsigned short normal_i2c[] = { 0x0d, I2C_CLIENT_END };
 101
 102 static s32 dcon_write(struct dcon_priv *dcon, u8 reg, u16 val)
 103 {
 104         return i2c_smbus_write_word_data(dcon->client, reg, val);
 105 }
 106
 107 static s32 dcon_read(struct dcon_priv *dcon, u8 reg)
 108 {
 109         return i2c_smbus_read_word_data(dcon->client, reg);
 110 }
 111
 112 /* The current backlight value - this saves us some smbus traffic */
 113 static int bl_val = -1;
 114
 115 /* ===== API functions - these are called by a variety of users ==== */
 116
 117 static int dcon_hw_init(struct dcon_priv *dcon, int is_init)
 118 {
 119         struct i2c_client *client = dcon->client;
 120         uint16_t ver;
 121         int rc = 0;
 122
 123         ver = i2c_smbus_read_word_data(client, DCON_REG_ID);
 124         if ((ver >> 8) != 0xDC) {
 125                 printk(KERN_ERR "olpc-dcon:  DCON ID not 0xDCxx: 0x%04x "
 126                                 "instead.\n", ver);
 127                 rc = -ENXIO;
 128                 goto err;
 129         }
 130
 131         if (is_init) {
 132                 printk(KERN_INFO "olpc-dcon:  Discovered DCON version %x\n",
 133                                 ver & 0xFF);
 134                 rc = pdata->init();
 135                 if (rc != 0) {
 136                         printk(KERN_ERR "olpc-dcon:  Unable to init.\n");
 137                         goto err;
 138                 }
 139         }
 140
 141         if (ver < 0xdc02 && !noinit) {
 142                 /* Initialize the DCON registers */
 143
 144                 /* Start with work-arounds for DCON ASIC */
 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, 0x4b, 0x00cc);
 148                 i2c_smbus_write_word_data(client, 0x0b, 0x007a);
 149                 i2c_smbus_write_word_data(client, 0x36, 0x025c);
 150                 i2c_smbus_write_word_data(client, 0x37, 0x025e);
 151
 152                 /* Initialise SDRAM */
 153
 154                 i2c_smbus_write_word_data(client, 0x3b, 0x002b);
 155                 i2c_smbus_write_word_data(client, 0x41, 0x0101);
 156                 i2c_smbus_write_word_data(client, 0x42, 0x0101);
 157         } else if (!noinit) {
 158                 /* SDRAM setup/hold time */
 159                 i2c_smbus_write_word_data(client, 0x3a, 0xc040);
 160                 i2c_smbus_write_word_data(client, 0x41, 0x0000);
 161                 i2c_smbus_write_word_data(client, 0x41, 0x0101);
 162                 i2c_smbus_write_word_data(client, 0x42, 0x0101);
 163         }
 164
 165         /* Colour swizzle, AA, no passthrough, backlight */
 166         if (is_init) {
 167                 dcon_disp_mode = MODE_PASSTHRU | MODE_BL_ENABLE | 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
 269 static int dcon_set_output(struct dcon_priv *dcon, int arg)
 270 {
 271         if (dcon_output == arg)
 272                 return 0;
 273
 274         dcon_output = arg;
 275
 276         if (arg == DCON_OUTPUT_MONO) {
 277                 dcon_disp_mode &= ~(MODE_CSWIZZLE | MODE_COL_AA);
 278                 dcon_disp_mode |= MODE_MONO_LUMA;
 279         } else {
 280                 dcon_disp_mode &= ~(MODE_MONO_LUMA);
 281                 dcon_disp_mode |= MODE_CSWIZZLE;
 282                 if (useaa)
 283                         dcon_disp_mode |= MODE_COL_AA;
 284         }
 285
 286         dcon_write(dcon, DCON_REG_MODE, dcon_disp_mode);
 287         return 0;
 288 }
 289
 290 /* For now, this will be really stupid - we need to address how
 291  * DCONLOAD works in a sleep and account for it accordingly
 292  */
 293
 294 static void dcon_sleep(struct dcon_priv *dcon, int state)
 295 {
 296         int x;
 297
 298         /* Turn off the backlight and put the DCON to sleep */
 299
 300         if (state == dcon_sleep_val)
 301                 return;
 302
 303         if (!olpc_board_at_least(olpc_board(0xc2)))
 304                 return;
 305
 306         if (state == DCON_SLEEP) {
 307                 x = 0;
 308                 x = olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0);
 309                 if (x)
 310                         printk(KERN_WARNING "olpc-dcon:  unable to force dcon "
 311                                         "to power down: %d!\n", x);
 312                 else
 313                         dcon_sleep_val = state;
 314         } else {
 315                 /* Only re-enable the backlight if the backlight value is set */
 316                 if (bl_val != 0)
 317                         dcon_disp_mode |= MODE_BL_ENABLE;
 318                 x = dcon_bus_stabilize(dcon, 1);
 319                 if (x)
 320                         printk(KERN_WARNING "olpc-dcon:  unable to reinit dcon"
 321                                         " hardware: %d!\n", x);
 322                 else
 323                         dcon_sleep_val = state;
 324
 325                 /* Restore backlight */
 326                 dcon_set_backlight_hw(dcon, bl_val);
 327         }
 328
 329         /* We should turn off some stuff in the framebuffer - but what? */
 330 }
 331
 332 /* the DCON seems to get confused if we change DCONLOAD too
 333  * frequently -- i.e., approximately faster than frame time.
 334  * normally we don't change it this fast, so in general we won't
 335  * delay here.
 336  */
 337 void dcon_load_holdoff(void)
 338 {
 339         struct timespec delta_t, now;
 340         while (1) {
 341                 getnstimeofday(&now);
 342                 delta_t = timespec_sub(now, dcon_load_time);
 343                 if (delta_t.tv_sec != 0 ||
 344                         delta_t.tv_nsec > NSEC_PER_MSEC * 20) {
 345                         break;
 346                 }
 347                 mdelay(4);
 348         }
 349 }
 350 /* Set the source of the display (CPU or DCON) */
 351
 352 static void dcon_source_switch(struct work_struct *work)
 353 {
 354         struct dcon_priv *dcon = container_of(work, struct dcon_priv,
 355                         switch_source);
 356         DECLARE_WAITQUEUE(wait, current);
 357         int source = dcon_pending;
 358
 359         if (dcon_source == source)
 360                 return;
 361
 362         dcon_load_holdoff();
 363
 364         dcon_switched = 0;
 365
 366         switch (source) {
 367         case DCON_SOURCE_CPU:
 368                 printk("dcon_source_switch to CPU\n");
 369                 /* Enable the scanline interrupt bit */
 370                 if (dcon_write(dcon, DCON_REG_MODE,
 371                                 dcon_disp_mode | MODE_SCAN_INT))
 372                         printk(KERN_ERR
 373                                "olpc-dcon:  couldn't enable scanline interrupt!\n");
 374                 else {
 375                         /* Wait up to one second for the scanline interrupt */
 376                         wait_event_timeout(dcon_wait_queue,
 377                                            dcon_switched == 1, HZ);
 378                 }
 379
 380                 if (!dcon_switched)
 381                         printk(KERN_ERR "olpc-dcon:  Timeout entering CPU mode; expect a screen glitch.\n");
 382
 383                 /* Turn off the scanline interrupt */
 384                 if (dcon_write(dcon, DCON_REG_MODE, dcon_disp_mode))
 385                         printk(KERN_ERR "olpc-dcon:  couldn't disable scanline interrupt!\n");
 386
 387                 /*
 388                  * Ideally we'd like to disable interrupts here so that the
 389                  * fb unblanking and DCON turn on happen at a known time value;
 390                  * however, we can't do that right now with fb_blank
 391                  * messing with semaphores.
 392                  *
 393                  * For now, we just hope..
 394                  */
 395                 console_lock();
 396                 ignore_fb_events = 1;
 397                 if (fb_blank(fbinfo, FB_BLANK_UNBLANK)) {
 398                         ignore_fb_events = 0;
 399                         console_unlock();
 400                         printk(KERN_ERR "olpc-dcon:  Failed to enter CPU mode\n");
 401                         dcon_pending = DCON_SOURCE_DCON;
 402                         return;
 403                 }
 404                 ignore_fb_events = 0;
 405                 console_unlock();
 406
 407                 /* And turn off the DCON */
 408                 pdata->set_dconload(1);
 409                 getnstimeofday(&dcon_load_time);
 410
 411                 printk(KERN_INFO "olpc-dcon: The CPU has control\n");
 412                 break;
 413         case DCON_SOURCE_DCON:
 414         {
 415                 int t;
 416                 struct timespec delta_t;
 417
 418                 printk(KERN_INFO "dcon_source_switch to DCON\n");
 419
 420                 add_wait_queue(&dcon_wait_queue, &wait);
 421                 set_current_state(TASK_UNINTERRUPTIBLE);
 422
 423                 /* Clear DCONLOAD - this implies that the DCON is in control */
 424                 pdata->set_dconload(0);
 425                 getnstimeofday(&dcon_load_time);
 426
 427                 t = schedule_timeout(HZ/2);
 428                 remove_wait_queue(&dcon_wait_queue, &wait);
 429                 set_current_state(TASK_RUNNING);
 430
 431                 if (!dcon_switched) {
 432                         printk(KERN_ERR "olpc-dcon: Timeout entering DCON mode; expect a screen glitch.\n");
 433                 } else {
 434                         /* sometimes the DCON doesn't follow its own rules,
 435                          * and doesn't wait for two vsync pulses before
 436                          * ack'ing the frame load with an IRQ.  the result
 437                          * is that the display shows the *previously*
 438                          * loaded frame.  we can detect this by looking at
 439                          * the time between asserting DCONLOAD and the IRQ --
 440                          * if it's less than 20msec, then the DCON couldn't
 441                          * have seen two VSYNC pulses.  in that case we
 442                          * deassert and reassert, and hope for the best.
 443                          * see http://dev.laptop.org/ticket/9664
 444                          */
 445                         delta_t = timespec_sub(dcon_irq_time, dcon_load_time);
 446                         if (dcon_switched && delta_t.tv_sec == 0 &&
 447                                         delta_t.tv_nsec < NSEC_PER_MSEC * 20) {
 448                                 printk(KERN_ERR "olpc-dcon: missed loading, retrying\n");
 449                                 pdata->set_dconload(1);
 450                                 mdelay(41);
 451                                 pdata->set_dconload(0);
 452                                 getnstimeofday(&dcon_load_time);
 453                                 mdelay(41);
 454                         }
 455                 }
 456
 457                 console_lock();
 458                 ignore_fb_events = 1;
 459                 if (fb_blank(fbinfo, FB_BLANK_POWERDOWN))
 460                         printk(KERN_ERR "olpc-dcon:  couldn't blank fb!\n");
 461                 ignore_fb_events = 0;
 462                 console_unlock();
 463
 464                 printk(KERN_INFO "olpc-dcon: The DCON has control\n");
 465                 break;
 466         }
 467         default:
 468                 BUG();
 469         }
 470
 471         dcon_source = source;
 472 }
 473
 474 static void dcon_set_source(struct dcon_priv *dcon, int arg)
 475 {
 476         if (dcon_pending == arg)
 477                 return;
 478
 479         dcon_pending = arg;
 480
 481         if ((dcon_source != arg) && !work_pending(&dcon->switch_source))
 482                 schedule_work(&dcon->switch_source);
 483 }
 484
 485 static void dcon_set_source_sync(struct dcon_priv *dcon, int arg)
 486 {
 487         dcon_set_source(dcon, arg);
 488         flush_scheduled_work();
 489 }
 490
 491 static int dconbl_set(struct backlight_device *dev)
 492 {
 493         struct dcon_priv *dcon = bl_get_data(dev);
 494         int level = dev->props.brightness;
 495
 496         if (dev->props.power != FB_BLANK_UNBLANK)
 497                 level = 0;
 498
 499         dcon_set_backlight(dcon, level);
 500         return 0;
 501 }
 502
 503 static int dconbl_get(struct backlight_device *dev)
 504 {
 505         struct dcon_priv *dcon = bl_get_data(dev);
 506         return dcon_get_backlight(dcon);
 507 }
 508
 509 static ssize_t dcon_mode_show(struct device *dev,
 510         struct device_attribute *attr, char *buf)
 511 {
 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         return sprintf(buf, "%d\n", dcon_sleep_val);
 520 }
 521
 522 static ssize_t dcon_freeze_show(struct device *dev,
 523         struct device_attribute *attr, char *buf)
 524 {
 525         return sprintf(buf, "%d\n", dcon_source == DCON_SOURCE_DCON ? 1 : 0);
 526 }
 527
 528 static ssize_t dcon_output_show(struct device *dev,
 529         struct device_attribute *attr, char *buf)
 530 {
 531         return sprintf(buf, "%d\n", dcon_output);
 532 }
 533
 534 static ssize_t dcon_resumeline_show(struct device *dev,
 535         struct device_attribute *attr, char *buf)
 536 {
 537         return sprintf(buf, "%d\n", resumeline);
 538 }
 539
 540 static int _strtoul(const char *buf, int len, unsigned int *val)
 541 {
 542
 543         char *endp;
 544         unsigned int output = simple_strtoul(buf, &endp, 0);
 545         int size = endp - buf;
 546
 547         if (*endp && isspace(*endp))
 548                 size++;
 549
 550         if (size != len)
 551                 return -EINVAL;
 552
 553         *val = output;
 554         return 0;
 555 }
 556
 557 static ssize_t dcon_output_store(struct device *dev,
 558         struct device_attribute *attr, const char *buf, size_t count)
 559 {
 560         int output;
 561         int rc = -EINVAL;
 562
 563         if (_strtoul(buf, count, &output))
 564                 return -EINVAL;
 565
 566         if (output == DCON_OUTPUT_COLOR || output == DCON_OUTPUT_MONO) {
 567                 dcon_set_output(dev_get_drvdata(dev), output);
 568                 rc = count;
 569         }
 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 ? DCON_SLEEP : DCON_ACTIVE);
 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(output, 0644, dcon_output_show, dcon_output_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 fb_notifier_callback(struct notifier_block *self,
 674                                 unsigned long event, void *data)
 675 {
 676         struct fb_event *evdata = data;
 677         struct backlight_device *bl = container_of(self,
 678                         struct backlight_device, fb_notif);
 679         struct dcon_priv *dcon = bl_get_data(bl);
 680         int *blank = (int *) evdata->data;
 681         if (((event != FB_EVENT_BLANK) && (event != FB_EVENT_CONBLANK)) ||
 682                         ignore_fb_events)
 683                 return 0;
 684         dcon_sleep(dcon, (*blank) ? DCON_SLEEP : DCON_ACTIVE);
 685         return 0;
 686 }
 687
 688 static struct notifier_block fb_nb = {
 689         .notifier_call = fb_notifier_callback,
 690 };
 691
 692 static int dcon_detect(struct i2c_client *client, struct i2c_board_info *info)
 693 {
 694         strlcpy(info->type, "olpc_dcon", I2C_NAME_SIZE);
 695
 696         return 0;
 697 }
 698
 699 static int dcon_probe(struct i2c_client *client, const struct i2c_device_id *id)
 700 {
 701         struct dcon_priv *dcon;
 702         int rc, i, j;
 703
 704         dcon = kzalloc(sizeof(*dcon), GFP_KERNEL);
 705         if (!dcon)
 706                 return -ENOMEM;
 707
 708         dcon->client = client;
 709         INIT_WORK(&dcon->switch_source, dcon_source_switch);
 710         dcon->reboot_nb.notifier_call = dcon_reboot_notify;
 711         dcon->reboot_nb.priority = -1;
 712
 713         i2c_set_clientdata(client, dcon);
 714
 715         if (num_registered_fb >= 1)
 716                 fbinfo = registered_fb[0];
 717
 718         rc = dcon_hw_init(dcon, 1);
 719         if (rc)
 720                 goto einit;
 721
 722         /* Add the DCON device */
 723
 724         dcon_device = platform_device_alloc("dcon", -1);
 725
 726         if (dcon_device == NULL) {
 727                 printk(KERN_ERR "dcon:  Unable to create the DCON device\n");
 728                 rc = -ENOMEM;
 729                 goto eirq;
 730         }
 731         rc = platform_device_add(dcon_device);
 732         platform_set_drvdata(dcon_device, dcon);
 733
 734         if (rc) {
 735                 printk(KERN_ERR "dcon:  Unable to add the DCON device\n");
 736                 goto edev;
 737         }
 738
 739         for (i = 0; i < ARRAY_SIZE(dcon_device_files); i++) {
 740                 rc = device_create_file(&dcon_device->dev,
 741                                         &dcon_device_files[i]);
 742                 if (rc) {
 743                         dev_err(&dcon_device->dev, "Cannot create sysfs file\n");
 744                         goto ecreate;
 745                 }
 746         }
 747
 748         /* Add the backlight device for the DCON */
 749         dcon_bl_dev = backlight_device_register("dcon-bl", &dcon_device->dev,
 750                 dcon, &dcon_bl_ops, NULL);
 751
 752         if (IS_ERR(dcon_bl_dev)) {
 753                 printk(KERN_ERR "Cannot register the backlight device (%ld)\n",
 754                        PTR_ERR(dcon_bl_dev));
 755                 dcon_bl_dev = NULL;
 756         } else {
 757                 dcon_bl_dev->props.max_brightness = 15;
 758                 dcon_bl_dev->props.power = FB_BLANK_UNBLANK;
 759                 dcon_bl_dev->props.brightness = dcon_get_backlight(dcon);
 760
 761                 backlight_update_status(dcon_bl_dev);
 762         }
 763
 764         register_reboot_notifier(&dcon->reboot_nb);
 765         atomic_notifier_chain_register(&panic_notifier_list, &dcon_panic_nb);
 766         fb_register_client(&fb_nb);
 767
 768         return 0;
 769
 770  ecreate:
 771         for (j = 0; j < i; j++)
 772                 device_remove_file(&dcon_device->dev, &dcon_device_files[j]);
 773  edev:
 774         platform_device_unregister(dcon_device);
 775         dcon_device = NULL;
 776  eirq:
 777         free_irq(DCON_IRQ, &dcon_driver);
 778  einit:
 779         i2c_set_clientdata(client, NULL);
 780         kfree(dcon);
 781         return rc;
 782 }
 783
 784 static int dcon_remove(struct i2c_client *client)
 785 {
 786         struct dcon_priv *dcon = i2c_get_clientdata(client);
 787
 788         i2c_set_clientdata(client, NULL);
 789
 790         fb_unregister_client(&fb_nb);
 791         unregister_reboot_notifier(&dcon->reboot_nb);
 792         atomic_notifier_chain_unregister(&panic_notifier_list, &dcon_panic_nb);
 793
 794         free_irq(DCON_IRQ, &dcon_driver);
 795
 796         if (dcon_bl_dev != NULL)
 797                 backlight_device_unregister(dcon_bl_dev);
 798
 799         if (dcon_device != NULL)
 800                 platform_device_unregister(dcon_device);
 801         cancel_work_sync(&dcon->switch_source);
 802
 803         kfree(dcon);
 804
 805         return 0;
 806 }
 807
 808 #ifdef CONFIG_PM
 809 static int dcon_suspend(struct i2c_client *client, pm_message_t state)
 810 {
 811         struct dcon_priv *dcon = i2c_get_clientdata(client);
 812
 813         if (dcon_sleep_val == DCON_ACTIVE) {
 814                 /* Set up the DCON to have the source */
 815                 dcon_set_source_sync(dcon, DCON_SOURCE_DCON);
 816         }
 817
 818         return 0;
 819 }
 820
 821 static int dcon_resume(struct i2c_client *client)
 822 {
 823         struct dcon_priv *dcon = i2c_get_clientdata(client);
 824
 825         if (dcon_sleep_val == DCON_ACTIVE) {
 826                 dcon_bus_stabilize(dcon, 0);
 827                 dcon_set_source(dcon, DCON_SOURCE_CPU);
 828         }
 829
 830         return 0;
 831 }
 832
 833 #endif
 834
 835
 836 static irqreturn_t dcon_interrupt(int irq, void *id)
 837 {
 838         int status = pdata->read_status();
 839
 840         if (status == -1)
 841                 return IRQ_NONE;
 842
 843         switch (status & 3) {
 844         case 3:
 845                 printk(KERN_DEBUG "olpc-dcon: DCONLOAD_MISSED interrupt\n");
 846                 break;
 847
 848         case 2: /* switch to DCON mode */
 849         case 1: /* switch to CPU mode */
 850                 dcon_switched = 1;
 851                 getnstimeofday(&dcon_irq_time);
 852                 wake_up(&dcon_wait_queue);
 853                 break;
 854
 855         case 0:
 856                 /* workaround resume case:  the DCON (on 1.5) doesn't
 857                  * ever assert status 0x01 when switching to CPU mode
 858                  * during resume.  this is because DCONLOAD is de-asserted
 859                  * _immediately_ upon exiting S3, so the actual release
 860                  * of the DCON happened long before this point.
 861                  * see http://dev.laptop.org/ticket/9869
 862                  */
 863                 if (dcon_source != dcon_pending && !dcon_switched) {
 864                         dcon_switched = 1;
 865                         getnstimeofday(&dcon_irq_time);
 866                         wake_up(&dcon_wait_queue);
 867                         printk(KERN_DEBUG "olpc-dcon: switching w/ status 0/0\n");
 868                 } else {
 869                         printk(KERN_DEBUG "olpc-dcon: scanline interrupt w/CPU\n");
 870                 }
 871         }
 872
 873         return IRQ_HANDLED;
 874 }
 875
 876 static struct i2c_device_id dcon_idtable[] = {
 877         { "olpc_dcon",  0 },
 878         { }
 879 };
 880
 881 MODULE_DEVICE_TABLE(i2c, dcon_idtable);
 882
 883 static struct i2c_driver dcon_driver = {
 884         .driver = {
 885                 .name   = "olpc_dcon",
 886         },
 887         .class = I2C_CLASS_DDC | I2C_CLASS_HWMON,
 888         .id_table = dcon_idtable,
 889         .probe = dcon_probe,
 890         .remove = __devexit_p(dcon_remove),
 891         .detect = dcon_detect,
 892         .address_list = normal_i2c,
 893 #ifdef CONFIG_PM
 894         .suspend = dcon_suspend,
 895         .resume = dcon_resume,
 896 #endif
 897 };
 898
 899 #include "olpc_dcon_xo_1.c"
 900
 901 static int __init olpc_dcon_init(void)
 902 {
 903         pdata = &dcon_pdata_xo_1;
 904
 905         i2c_add_driver(&dcon_driver);
 906         return 0;
 907 }
 908
 909 static void __exit olpc_dcon_exit(void)
 910 {
 911         i2c_del_driver(&dcon_driver);
 912 }
 913
 914 module_init(olpc_dcon_init);
 915 module_exit(olpc_dcon_exit);
 916
 917 MODULE_LICENSE("GPL");