target/linux/olpc/files/drivers/video/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  *
   7  * This program is free software.  You can redistribute it and/or
   8  * modify it under the terms of version 2 of the GNU General Public
   9  * License as published by the Free Software Foundation.
  10  */
  11
  12
  13 #include <linux/kernel.h>
  14 #include <linux/fb.h>
  15 #include <linux/i2c.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/i2c-id.h>
  18 #include <linux/pci.h>
  19 #include <linux/vt_kern.h>
  20 #include <linux/pci_ids.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/delay.h>
  23 #include <linux/backlight.h>
  24 #include <linux/device.h>
  25 #include <asm/uaccess.h>
  26 #include <linux/ctype.h>
  27 #include <linux/reboot.h>
  28 #include <asm/tsc.h>
  29 #include <asm/olpc.h>
  30
  31 #include "olpc_dcon.h"
  32
  33 /* Module definitions */
  34
  35 static int resumeline = 898;
  36 module_param(resumeline, int, 0444);
  37
  38 static int noinit;
  39 module_param(noinit, int, 0444);
  40
  41 /* Default off since it doesn't work on DCON ASIC in B-test OLPC board */
  42 static int useaa = 1;
  43 module_param(useaa, int, 0444);
  44
  45 /* I2C structures */
  46
  47 static struct i2c_driver dcon_driver;
  48 static struct i2c_client *dcon_client;
  49
  50 /* Platform devices */
  51 static struct platform_device *dcon_device;
  52
  53 /* Backlight device */
  54 static struct backlight_device *dcon_bl_dev;
  55
  56 /* Base address of the GPIO registers */
  57 static unsigned long gpio_base;
  58
  59 static struct fb_info *fbinfo;
  60
  61 /* Current source, initialized at probe time */
  62 static int dcon_source;
  63
  64 /* Desired source */
  65 static int dcon_pending;
  66
  67 /* Current output type */
  68 static int dcon_output = DCON_OUTPUT_COLOR;
  69
  70 /* Current sleep status (not yet implemented) */
  71 static int dcon_sleep_val = DCON_ACTIVE;
  72
  73 /* Shadow register for the DCON_REG_MODE register */
  74 static unsigned short dcon_disp_mode;
  75
  76 /* Variables used during switches */
  77 static int dcon_switched;
  78
  79 static DECLARE_WAIT_QUEUE_HEAD(dcon_wait_queue);
  80
  81 static unsigned short normal_i2c[] = { 0x0D, I2C_CLIENT_END };
  82 I2C_CLIENT_INSMOD;
  83
  84 #define dcon_write(reg,val) i2c_smbus_write_word_data(dcon_client,reg,val)
  85 #define dcon_read(reg) i2c_smbus_read_word_data(dcon_client,reg)
  86
  87 /* The current backlight value - this saves us some smbus traffic */
  88 static int bl_val = -1;
  89
  90 /* ===== API functions - these are called by a variety of users ==== */
  91
  92 /* Backlight notes - turning off the backlight enable bit in the DCON
  93  * doesn't save us any power over just pushing the BL to zero, so we
  94  * don't use that bit in this code.
  95  */
  96
  97 static int dcon_get_backlight(void)
  98 {
  99         if (dcon_client == NULL)
 100                 return 0;
 101
 102         if (bl_val == -1)
 103                 bl_val = dcon_read(DCON_REG_BRIGHT) & 0x0F;
 104
 105         return bl_val;
 106 }
 107
 108 static void dcon_set_backlight(int level)
 109 {
 110         if (dcon_client == NULL)
 111                 return;
 112
 113         if (bl_val == (level & 0x0F))
 114                 return;
 115
 116         bl_val = level & 0x0F;
 117         dcon_write(DCON_REG_BRIGHT, bl_val);
 118
 119         /* Purposely turn off the backlight when we go to level 0 */
 120
 121         if (bl_val == 0) {
 122           dcon_disp_mode &= ~MODE_BL_ENABLE;
 123           dcon_write(DCON_REG_MODE, dcon_disp_mode);
 124         }
 125         else if (!(dcon_disp_mode & MODE_BL_ENABLE)) {
 126           dcon_disp_mode |= MODE_BL_ENABLE;
 127           dcon_write(DCON_REG_MODE, dcon_disp_mode);
 128         }
 129 }
 130
 131 /* Set the output type to either color or mono */
 132
 133 static int dcon_set_output(int arg)
 134 {
 135         if (dcon_output == arg)
 136                 return 0;
 137
 138         dcon_output = arg;
 139
 140         if (arg == DCON_OUTPUT_MONO) {
 141                 dcon_disp_mode &= ~(MODE_CSWIZZLE | MODE_COL_AA);
 142                 dcon_disp_mode |= MODE_MONO_LUMA;
 143         }
 144         else {
 145                 dcon_disp_mode &= ~(MODE_MONO_LUMA);
 146                 dcon_disp_mode |= MODE_CSWIZZLE;
 147                 if (useaa)
 148                         dcon_disp_mode |= MODE_COL_AA;
 149         }
 150
 151         dcon_write(DCON_REG_MODE, dcon_disp_mode);
 152         return 0;
 153 }
 154
 155 /* For now, this will be really stupid - we need to address how
 156  * DCONLOAD works in a sleep and account for it accordingly
 157  */
 158
 159 static void dcon_sleep(int state)
 160 {
 161         /* Turn off the backlight and put the DCON to sleep */
 162
 163         if (state == dcon_sleep_val)
 164                 return;
 165
 166         if (state == DCON_SLEEP) {
 167                 dcon_disp_mode &= ~MODE_BL_ENABLE;
 168                 dcon_disp_mode |= MODE_SLEEP;
 169         }
 170         else {
 171                 /* Only re-enable the backlight if the backlight value is set */
 172
 173                 if (bl_val != 0)
 174                         dcon_disp_mode |= MODE_BL_ENABLE;
 175
 176                 dcon_disp_mode &= ~MODE_SLEEP;
 177         }
 178
 179         dcon_sleep_val = state;
 180         dcon_write(DCON_REG_MODE, dcon_disp_mode);
 181
 182         /* We should turn off some stuff in the framebuffer - but what? */
 183 }
 184
 185 /* Set the source of the display (CPU or DCON) */
 186
 187 static void dcon_source_switch(struct work_struct *work)
 188 {
 189         DECLARE_WAITQUEUE(wait, current);
 190         int source = dcon_pending;
 191
 192         if (dcon_source == source)
 193                 return;
 194
 195         dcon_switched = 0;
 196
 197         switch (source) {
 198         case DCON_SOURCE_CPU:
 199
 200                 /* Enable the scanline interrupt bit */
 201                 if (dcon_write(DCON_REG_MODE, dcon_disp_mode | MODE_SCAN_INT))
 202                         printk(KERN_ERR "olpc-dcon:  couldn't enable scanline interrupt!\n");
 203                 else {
 204                         /* Wait up to one second for the scanline interrupt */
 205                         wait_event_timeout(dcon_wait_queue, dcon_switched == 1, HZ);
 206                 }
 207
 208                 if (!dcon_switched)
 209                         printk(KERN_ERR "olpc-dcon:  Timeout entering CPU mode; expect a screen glitch.\n");
 210
 211                 /*
 212                  * Ideally we'd like to disable interrupts here so that the
 213                  * fb_powerup and DCON turn on happen at a known time value;
 214                  * however, we can't do that right now with fb_set_suspend
 215                  * messing with semaphores.
 216                  *
 217                  * For now, we just hope..
 218                  */
 219                 if (fb_powerup(fbinfo)) {
 220                         printk(KERN_ERR "olpc-dcon:  Failed to enter CPU mode\n");
 221                         dcon_pending = DCON_SOURCE_DCON;
 222                         return;
 223                 }
 224
 225                 /* And turn off the DCON */
 226                 outl(1<<11, gpio_base + GPIOx_OUT_VAL);
 227
 228                 /* Turn off the scanline interrupt */
 229                 if (dcon_write(DCON_REG_MODE, dcon_disp_mode))
 230                         printk(KERN_ERR "olpc-dcon:  couldn't disable scanline interrupt!\n");
 231
 232                 printk(KERN_INFO "olpc-dcon: The CPU has control\n");
 233                 break;
 234         case DCON_SOURCE_DCON:
 235         {
 236                 int t;
 237
 238                 add_wait_queue(&dcon_wait_queue, &wait);
 239                 set_current_state(TASK_UNINTERRUPTIBLE);
 240
 241                 /* Clear GPIO11 (DCONLOAD) - this implies that the DCON is in
 242                    control */
 243
 244                 outl(1 << (11 + 16), gpio_base + GPIOx_OUT_VAL);
 245
 246                 t = schedule_timeout(HZ/2);
 247                 remove_wait_queue(&dcon_wait_queue, &wait);
 248                 set_current_state(TASK_RUNNING);
 249
 250                 if (!dcon_switched)
 251                         printk(KERN_ERR "olpc-dcon: Timeout entering DCON mode; expect a screen glitch.\n");
 252
 253                 /* Turn off the graphics engine completely */
 254                 fb_powerdown(fbinfo);
 255
 256                 printk(KERN_INFO "olpc-dcon: The DCON has control\n");
 257                 break;
 258         }
 259         default:
 260                 BUG();
 261         }
 262
 263         dcon_source = source;
 264 }
 265
 266 static DECLARE_WORK(dcon_work, dcon_source_switch);
 267
 268 static int dcon_set_source(int arg)
 269 {
 270         if (arg != DCON_SOURCE_CPU && arg != DCON_SOURCE_DCON)
 271                 return -EINVAL;
 272
 273         if (dcon_pending == arg)
 274                 return 0;
 275
 276         dcon_pending = arg;
 277         if ((dcon_source != arg) && !work_pending(&dcon_work))
 278                 schedule_work(&dcon_work);
 279
 280         return 0;
 281 }
 282
 283 static int dcon_set_source_sync(int arg)
 284 {
 285         int ret = dcon_set_source(arg);
 286         if (!ret)
 287                 flush_scheduled_work();
 288         return ret;
 289 }
 290
 291 static int dconbl_set(struct backlight_device *dev) {
 292
 293         int level = dev->props.brightness;
 294
 295         if (dev->props.power != FB_BLANK_UNBLANK)
 296                 level = 0;
 297
 298         dcon_set_backlight(level);
 299         return 0;
 300 }
 301
 302 static int dconbl_get(struct backlight_device *dev) {
 303         return dcon_get_backlight();
 304 }
 305
 306 static ssize_t dcon_mode_show(struct device *dev,
 307         struct device_attribute *attr, char *buf)
 308 {
 309         return sprintf(buf, "%4.4X\n", dcon_disp_mode);
 310 }
 311
 312 static ssize_t dcon_sleep_show(struct device *dev,
 313         struct device_attribute *attr, char *buf)
 314 {
 315         return sprintf(buf, "%d\n", dcon_sleep_val);
 316 }
 317
 318 static ssize_t /* __deprecated */ dcon_source_show(struct device *dev,
 319         struct device_attribute *attr, char *buf)
 320 {
 321         printk(KERN_WARNING "olpc-dcon:  using deprecated sysfs 'source' interface; use 'freeze' instead!\n");
 322         return sprintf(buf, "%d\n", dcon_source);
 323 }
 324
 325 static ssize_t dcon_freeze_show(struct device *dev,
 326         struct device_attribute *attr, char *buf)
 327 {
 328         return sprintf(buf, "%d\n", dcon_source == DCON_SOURCE_DCON ? 1 : 0);
 329 }
 330
 331 static ssize_t dcon_output_show(struct device *dev,
 332         struct device_attribute *attr, char *buf)
 333 {
 334         return sprintf(buf, "%d\n", dcon_output);
 335 }
 336
 337 static ssize_t dcon_resumeline_show(struct device *dev,
 338         struct device_attribute *attr, char *buf)
 339 {
 340         return sprintf(buf, "%d\n", resumeline);
 341 }
 342
 343 static int _strtoul(const char *buf, int len, unsigned int *val)
 344 {
 345
 346         char *endp;
 347         unsigned int output = simple_strtoul(buf, &endp, 0);
 348         int size = endp - buf;
 349
 350         if (*endp && isspace(*endp))
 351                 size++;
 352
 353         if (size != len)
 354                 return -EINVAL;
 355
 356         *val = output;
 357         return 0;
 358 }
 359
 360 static ssize_t dcon_output_store(struct device *dev,
 361         struct device_attribute *attr, const char *buf, size_t count)
 362 {
 363         int output;
 364         int rc = -EINVAL;
 365
 366         if (_strtoul(buf, count, &output))
 367                 return -EINVAL;
 368
 369         if (output == DCON_OUTPUT_COLOR || output == DCON_OUTPUT_MONO) {
 370                 dcon_set_output(output);
 371                 rc = count;
 372         }
 373
 374         return rc;
 375 }
 376
 377 static ssize_t /* __deprecated */ dcon_source_store(struct device *dev,
 378         struct device_attribute *attr, const char *buf, size_t count)
 379 {
 380         int output;
 381         int rc = -EINVAL;
 382
 383         printk(KERN_WARNING "olpc-dcon:  using deprecated sysfs 'source' interface; use 'freeze' instead!\n");
 384         if (_strtoul(buf, count, &output))
 385                 return -EINVAL;
 386
 387         dcon_set_source(output);
 388         rc = count;
 389
 390         return rc;
 391 }
 392
 393 static ssize_t dcon_freeze_store(struct device *dev,
 394         struct device_attribute *attr, const char *buf, size_t count)
 395 {
 396         int output;
 397         int rc = -EINVAL;
 398
 399         if (_strtoul(buf, count, &output))
 400                 return rc;
 401
 402         dcon_set_source(output ? DCON_SOURCE_DCON : DCON_SOURCE_CPU);
 403         rc = count;
 404
 405         return rc;
 406 }
 407
 408 static ssize_t dcon_resumeline_store(struct device *dev,
 409         struct device_attribute *attr, const char *buf, size_t count)
 410 {
 411         int rl;
 412         int rc = -EINVAL;
 413
 414         if (_strtoul(buf, count, &rl))
 415                 return rc;
 416
 417         resumeline = rl;
 418         dcon_write(DCON_REG_SCAN_INT, resumeline);
 419         rc = count;
 420
 421         return rc;
 422 }
 423
 424 static ssize_t dcon_sleep_store(struct device *dev,
 425         struct device_attribute *attr, const char *buf, size_t count)
 426 {
 427         int output;
 428
 429         if (_strtoul(buf, count, &output))
 430                 return -EINVAL;
 431
 432         dcon_sleep(output ? DCON_SLEEP : DCON_ACTIVE);
 433         return count;
 434 }
 435
 436 static struct device_attribute dcon_device_files[] = {
 437         __ATTR(mode, 0444, dcon_mode_show, NULL),
 438         __ATTR(sleep, 0644, dcon_sleep_show, dcon_sleep_store),
 439         __ATTR(source, 0644, dcon_source_show, dcon_source_store),
 440         __ATTR(freeze, 0644, dcon_freeze_show, dcon_freeze_store),
 441         __ATTR(output, 0644, dcon_output_show, dcon_output_store),
 442         __ATTR(resumeline, 0644, dcon_resumeline_show, dcon_resumeline_store),
 443 };
 444
 445 static struct backlight_ops dcon_bl_ops = {
 446         .get_brightness = dconbl_get,
 447         .update_status = dconbl_set
 448 };
 449
 450 /* List of GPIOs that we care about:
 451    (in)  GPIO12   -- DCONBLNK
 452    (in)  GPIO[56] -- DCONSTAT[01]
 453    (out) GPIO11   -- DCONLOAD
 454 */
 455
 456 #define IN_GPIOS ((1<<5) | (1<<6) | (1<<7) | (1<<12))
 457 #define OUT_GPIOS (1<<11)
 458
 459 static irqreturn_t dcon_interrupt(int, void *);
 460
 461 static int dcon_request_irq(void)
 462 {
 463         unsigned long lo, hi;
 464         unsigned char lob;
 465
 466         rdmsr(MSR_LBAR_GPIO, lo, hi);
 467
 468         /* Check the mask and whether GPIO is enabled (sanity check) */
 469         if (hi != 0x0000f001) {
 470                 printk(KERN_ERR "GPIO not enabled -- cannot use DCON\n");
 471                 return -ENODEV;
 472         }
 473
 474         /* Mask off the IO base address */
 475         gpio_base = lo & 0x0000ff00;
 476
 477         /* Turn off the event enable for GPIO7 just to be safe */
 478         outl(1 << (16+7), gpio_base + GPIOx_EVNT_EN);
 479
 480         /* Set the directions for the GPIO pins */
 481         outl(OUT_GPIOS | (IN_GPIOS << 16), gpio_base + GPIOx_OUT_EN);
 482         outl(IN_GPIOS | (OUT_GPIOS << 16), gpio_base + GPIOx_IN_EN);
 483
 484         /* Set up the interrupt mappings */
 485
 486         /* Set the IRQ to pair 2 */
 487         geode_gpio_event_irq(OLPC_GPIO_DCON_IRQ, 2);
 488
 489         /* Enable group 2 to trigger the DCON interrupt */
 490         geode_gpio_set_irq(2, DCON_IRQ);
 491
 492         /* Select edge level for interrupt (in PIC) */
 493
 494         lob = inb(0x4d0);
 495         lob &= ~(1 << DCON_IRQ);
 496         outb(lob, 0x4d0);
 497
 498         /* Register the interupt handler */
 499         if (request_irq(DCON_IRQ, &dcon_interrupt, 0, "DCON", &dcon_driver))
 500                 return -EIO;
 501
 502         /* Clear INV_EN for GPIO7 (DCONIRQ) */
 503         outl((1<<(16+7)), gpio_base + GPIOx_INV_EN);
 504
 505         /* Enable filter for GPIO12 (DCONBLANK) */
 506         outl(1<<(12), gpio_base + GPIOx_IN_FLTR_EN);
 507
 508         /* Disable filter for GPIO7 */
 509         outl(1<<(16+7), gpio_base + GPIOx_IN_FLTR_EN);
 510
 511         /* Disable event counter for GPIO7 (DCONIRQ) and GPIO12 (DCONBLANK) */
 512
 513         outl(1<<(16+7), gpio_base + GPIOx_EVNTCNT_EN);
 514         outl(1<<(16+12), gpio_base + GPIOx_EVNTCNT_EN);
 515
 516         /* Add GPIO12 to the Filter Event Pair #7 */
 517         outb(12, gpio_base + GPIO_FE7_SEL);
 518
 519         /* Turn off negative Edge Enable for GPIO12 */
 520         outl(1<<(16+12), gpio_base + GPIOx_NEGEDGE_EN);
 521
 522         /* Enable negative Edge Enable for GPIO7 */
 523         outl(1<<7, gpio_base + GPIOx_NEGEDGE_EN);
 524
 525         /* Zero the filter amount for Filter Event Pair #7 */
 526         outw(0, gpio_base + GPIO_FLT7_AMNT);
 527
 528         /* Clear the negative edge status for GPIO7 and GPIO12 */
 529         outl((1<<7) | (1<<12), gpio_base+0x4c);
 530
 531         /* FIXME:  Clear the posiitive status as well, just to be sure */
 532         outl((1<<7) | (1<<12), gpio_base+0x48);
 533
 534         /* Enable events for GPIO7 (DCONIRQ) and GPIO12 (DCONBLANK) */
 535         outl((1<<(7))|(1<<12), gpio_base + GPIOx_EVNT_EN);
 536
 537         /* Determine the current state by reading the GPIO bit */
 538         /* Earlier stages of the boot process have established the state */
 539         dcon_source = inl(gpio_base + GPIOx_OUT_VAL) & (1<<11)
 540                 ? DCON_SOURCE_CPU
 541                 : DCON_SOURCE_DCON;
 542         dcon_pending = dcon_source;
 543
 544         return 0;
 545 }
 546
 547 static int dcon_reboot_notify(struct notifier_block *nb, unsigned long foo, void *bar)
 548 {
 549         if (dcon_client == NULL)
 550                 return 0;
 551
 552         /* Turn off the DCON. Entirely. */
 553         dcon_write(DCON_REG_MODE, 0x39);
 554         dcon_write(DCON_REG_MODE, 0x32);
 555         return 0;
 556 }
 557
 558 static int dcon_conswitch_notify(struct notifier_block *nb,
 559                                  unsigned long mode, void *dummy)
 560 {
 561         if (mode == CONSOLE_EVENT_SWITCH_TEXT)
 562                 dcon_sleep(DCON_ACTIVE);
 563
 564         return 0;
 565 }
 566
 567 static struct notifier_block dcon_nb = {
 568         .notifier_call = dcon_reboot_notify,
 569         .priority = -1,
 570 };
 571
 572 static struct notifier_block dcon_console_nb = {
 573         .notifier_call = dcon_conswitch_notify,
 574         .priority = -1,
 575 };
 576
 577 static int dcon_probe(struct i2c_adapter *adap, int addr, int kind)
 578 {
 579         struct i2c_client *client;
 580         uint16_t ver;
 581         int rc, i;
 582
 583         if (!olpc_has_dcon()) {
 584                 printk("olpc-dcon:  No DCON is attached.\n");
 585                 return -ENODEV;
 586         }
 587
 588         if (num_registered_fb >= 1)
 589                 fbinfo = registered_fb[0];
 590
 591         if (adap->id != I2C_HW_SMBUS_SCX200) {
 592                 printk(KERN_ERR "olpc-dcon: Invalid I2C bus (%d not %d)\n",
 593                        adap->id, I2C_HW_SMBUS_SCX200);
 594                 return -ENXIO;
 595         }
 596
 597         client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
 598         if (client == NULL)
 599                 return -ENOMEM;
 600
 601         strncpy(client->name, "OLPC-DCON", I2C_NAME_SIZE);
 602         client->addr = addr;
 603         client->adapter = adap;
 604         client->driver = &dcon_driver;
 605
 606         if ((rc = i2c_attach_client(client)) != 0) {
 607                 printk(KERN_ERR "olpc-dcon: Unable to attach the I2C client.\n");
 608                 goto eclient;
 609         }
 610
 611         ver = i2c_smbus_read_word_data(client, DCON_REG_ID);
 612
 613         if ((ver >> 8) != 0xDC) {
 614                 printk(KERN_ERR "olpc-dcon: DCON ID not 0xDCxx: 0x%04x instead.\n", ver);
 615                 rc = -ENXIO;
 616                 goto ei2c;
 617         }
 618
 619         if ((rc = dcon_request_irq())) {
 620                 printk(KERN_ERR "olpc-dcon: Unable to grab IRQ.\n");
 621                 goto ei2c;
 622         }
 623
 624         if (ver < 0xdc02 && !noinit) {
 625                 /* Initialize the DCON registers */
 626
 627                 /* Start with work-arounds for DCON ASIC */
 628                 i2c_smbus_write_word_data(client, 0x4b, 0x00cc);
 629                 i2c_smbus_write_word_data(client, 0x4b, 0x00cc);
 630                 i2c_smbus_write_word_data(client, 0x4b, 0x00cc);
 631                 i2c_smbus_write_word_data(client, 0x0b, 0x007a);
 632                 i2c_smbus_write_word_data(client, 0x36, 0x025c);
 633                 i2c_smbus_write_word_data(client, 0x37, 0x025e);
 634
 635                 /* Initialise SDRAM */
 636
 637                 i2c_smbus_write_word_data(client, 0x3b, 0x002b);
 638                 i2c_smbus_write_word_data(client, 0x41, 0x0101);
 639                 i2c_smbus_write_word_data(client, 0x42, 0x0101);
 640         }
 641
 642         /* Colour swizzle, AA, no passthrough, backlight */
 643
 644         dcon_disp_mode = MODE_PASSTHRU | MODE_BL_ENABLE | MODE_CSWIZZLE;
 645         if (useaa)
 646                 dcon_disp_mode |= MODE_COL_AA;
 647         i2c_smbus_write_word_data(client, DCON_REG_MODE, dcon_disp_mode);
 648
 649
 650         /* Set the scanline to interrupt on during resume */
 651
 652         i2c_smbus_write_word_data(client, DCON_REG_SCAN_INT, resumeline);
 653
 654         /* Add the DCON device */
 655
 656         dcon_device = platform_device_alloc("dcon", -1);
 657
 658         if (dcon_device == NULL) {
 659                 printk(KERN_ERR "dcon:  Unable to create the DCON device\n");
 660                 rc = -ENOMEM;
 661                 goto eirq;
 662         }
 663
 664         if ((rc = platform_device_add(dcon_device))) {
 665                 printk(KERN_ERR "dcon:  Unable to add the DCON device\n");
 666                 goto edev;
 667         }
 668
 669         for(i = 0; i < ARRAY_SIZE(dcon_device_files); i++)
 670                 device_create_file(&dcon_device->dev, &dcon_device_files[i]);
 671
 672         /* Add the backlight device for the DCON */
 673
 674         dcon_client = client;
 675
 676         dcon_bl_dev = backlight_device_register("dcon-bl", &dcon_device->dev,
 677                 NULL, &dcon_bl_ops);
 678
 679         if (IS_ERR(dcon_bl_dev)) {
 680                 printk(KERN_INFO "Could not register the backlight device for the DCON (%ld)\n", PTR_ERR(dcon_bl_dev));
 681                 dcon_bl_dev = NULL;
 682         }
 683         else {
 684                 dcon_bl_dev->props.max_brightness = 15;
 685                 dcon_bl_dev->props.power = FB_BLANK_UNBLANK;
 686                 dcon_bl_dev->props.brightness = dcon_get_backlight();
 687
 688                 backlight_update_status(dcon_bl_dev);
 689         }
 690
 691         register_reboot_notifier(&dcon_nb);
 692         console_event_register(&dcon_console_nb);
 693
 694         printk(KERN_INFO "olpc-dcon: Discovered DCON version %x\n", ver & 0xFF);
 695
 696         return 0;
 697
 698  edev:
 699         platform_device_unregister(dcon_device);
 700         dcon_device = NULL;
 701  eirq:
 702         free_irq(DCON_IRQ, &dcon_driver);
 703  ei2c:
 704         i2c_detach_client(client);
 705  eclient:
 706         kfree(client);
 707
 708         return rc;
 709 }
 710
 711 static int dcon_attach(struct i2c_adapter *adap)
 712 {
 713         int ret;
 714
 715         ret = i2c_probe(adap, &addr_data, dcon_probe);
 716
 717         if (dcon_client == NULL)
 718                 printk(KERN_ERR "olpc-dcon: No DCON found on SMBus\n");
 719
 720         return ret;
 721 }
 722
 723 static int dcon_detach(struct i2c_client *client)
 724 {
 725         int rc;
 726         dcon_client = NULL;
 727
 728         unregister_reboot_notifier(&dcon_nb);
 729         console_event_unregister(&dcon_console_nb);
 730
 731         free_irq(DCON_IRQ, &dcon_driver);
 732
 733         if ((rc = i2c_detach_client(client)) == 0)
 734                 kfree(i2c_get_clientdata(client));
 735
 736         if (dcon_bl_dev != NULL)
 737                 backlight_device_unregister(dcon_bl_dev);
 738
 739         if (dcon_device != NULL)
 740                 platform_device_unregister(dcon_device);
 741         cancel_work_sync(&dcon_work);
 742
 743         return rc;
 744 }
 745
 746
 747 #ifdef CONFIG_PM
 748 static int dcon_suspend(struct i2c_client *client, pm_message_t state)
 749 {
 750         if (dcon_sleep_val != DCON_ACTIVE)
 751                 return 0;
 752
 753         /* Set up the DCON to have the source */
 754         return dcon_set_source_sync(DCON_SOURCE_DCON);
 755 }
 756
 757 static int dcon_resume(struct i2c_client *client)
 758 {
 759         int x;
 760         if (dcon_sleep_val != DCON_ACTIVE)
 761                 return 0;
 762
 763         /* HACK: ensure the bus is stable */
 764         do {
 765                 x = dcon_read(DCON_REG_ID);
 766         } while (x < 0);
 767
 768         return dcon_set_source(DCON_SOURCE_CPU);
 769 }
 770
 771 #endif
 772
 773 static irqreturn_t dcon_interrupt(int irq, void *id)
 774 {
 775         int status = inl(gpio_base + GPIOx_READ_BACK) >> 5;
 776
 777         /* Clear the negative edge status for GPIO7 */
 778         outl(1 << 7, gpio_base + GPIOx_NEGEDGE_STS);
 779
 780         switch (status & 3) {
 781         case 3:
 782                 printk(KERN_DEBUG "olpc-dcon: DCONLOAD_MISSED interrupt\n");
 783                 break;
 784         case 2: /* switch to DCON mode */
 785         case 1: /* switch to CPU mode */
 786                 dcon_switched = 1;
 787                 wake_up(&dcon_wait_queue);
 788                 break;
 789         case 0:
 790                 printk(KERN_DEBUG "olpc-dcon: scanline interrupt w/CPU\n");
 791         }
 792
 793         return IRQ_HANDLED;
 794 }
 795
 796 static struct i2c_driver dcon_driver = {
 797         .driver = {
 798                 .name   = "OLPC-DCON",
 799         },
 800         .id = I2C_DRIVERID_DCON,
 801         .attach_adapter = dcon_attach,
 802         .detach_client = dcon_detach,
 803 #ifdef CONFIG_PM
 804         .suspend = dcon_suspend,
 805         .resume = dcon_resume,
 806 #endif
 807 };
 808
 809
 810 static int __init olpc_dcon_init(void)
 811 {
 812         i2c_add_driver(&dcon_driver);
 813         return 0;
 814 }
 815
 816 static void __exit olpc_dcon_exit(void)
 817 {
 818         i2c_del_driver(&dcon_driver);
 819 }
 820
 821 module_init(olpc_dcon_init);
 822 module_exit(olpc_dcon_exit);
 823
 824 MODULE_LICENSE("GPL");