2 * Mainly by David Woodhouse, somewhat modified by Jordan Crouse
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>
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.
15 #include <linux/kernel.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>
33 #include "olpc_dcon.h"
35 /* Module definitions */
37 static int resumeline = 898;
38 module_param(resumeline, int, 0444);
41 module_param(noinit, int, 0444);
43 /* Default off since it doesn't work on DCON ASIC in B-test OLPC board */
45 module_param(useaa, int, 0444);
47 struct dcon_platform_data {
49 void (*bus_stabilize_wiggle)(void);
50 void (*set_dconload)(int);
51 u8 (*read_status)(void);
54 static struct dcon_platform_data *pdata;
57 struct i2c_client *client;
59 struct work_struct switch_source;
60 struct notifier_block reboot_nb;
62 /* Shadow register for the DCON_REG_MODE register */
65 /* Current output type; true == mono, false == color */
72 static struct i2c_driver dcon_driver;
74 /* Platform devices */
75 static struct platform_device *dcon_device;
77 /* Backlight device */
78 static struct backlight_device *dcon_bl_dev;
80 static struct fb_info *fbinfo;
82 /* set this to 1 while controlling fb blank state from this driver */
83 static int ignore_fb_events = 0;
85 /* Current source, initialized at probe time */
86 static int dcon_source;
89 static int dcon_pending;
91 /* Variables used during switches */
92 static int dcon_switched;
93 static struct timespec dcon_irq_time;
94 static struct timespec dcon_load_time;
96 static DECLARE_WAIT_QUEUE_HEAD(dcon_wait_queue);
98 static unsigned short normal_i2c[] = { 0x0d, I2C_CLIENT_END };
100 static s32 dcon_write(struct dcon_priv *dcon, u8 reg, u16 val)
102 return i2c_smbus_write_word_data(dcon->client, reg, val);
105 static s32 dcon_read(struct dcon_priv *dcon, u8 reg)
107 return i2c_smbus_read_word_data(dcon->client, reg);
110 /* The current backlight value - this saves us some smbus traffic */
111 static int bl_val = -1;
113 /* ===== API functions - these are called by a variety of users ==== */
115 static int dcon_hw_init(struct dcon_priv *dcon, int is_init)
117 struct i2c_client *client = dcon->client;
121 ver = i2c_smbus_read_word_data(client, DCON_REG_ID);
122 if ((ver >> 8) != 0xDC) {
123 printk(KERN_ERR "olpc-dcon: DCON ID not 0xDCxx: 0x%04x "
130 printk(KERN_INFO "olpc-dcon: Discovered DCON version %x\n",
134 printk(KERN_ERR "olpc-dcon: Unable to init.\n");
139 if (ver < 0xdc02 && !noinit) {
140 /* Initialize the DCON registers */
142 /* Start with work-arounds for DCON ASIC */
143 i2c_smbus_write_word_data(client, 0x4b, 0x00cc);
144 i2c_smbus_write_word_data(client, 0x4b, 0x00cc);
145 i2c_smbus_write_word_data(client, 0x4b, 0x00cc);
146 i2c_smbus_write_word_data(client, 0x0b, 0x007a);
147 i2c_smbus_write_word_data(client, 0x36, 0x025c);
148 i2c_smbus_write_word_data(client, 0x37, 0x025e);
150 /* Initialise SDRAM */
152 i2c_smbus_write_word_data(client, 0x3b, 0x002b);
153 i2c_smbus_write_word_data(client, 0x41, 0x0101);
154 i2c_smbus_write_word_data(client, 0x42, 0x0101);
155 } else if (!noinit) {
156 /* SDRAM setup/hold time */
157 i2c_smbus_write_word_data(client, 0x3a, 0xc040);
158 i2c_smbus_write_word_data(client, 0x41, 0x0000);
159 i2c_smbus_write_word_data(client, 0x41, 0x0101);
160 i2c_smbus_write_word_data(client, 0x42, 0x0101);
163 /* Colour swizzle, AA, no passthrough, backlight */
165 dcon->disp_mode = MODE_PASSTHRU | MODE_BL_ENABLE |
168 dcon->disp_mode |= MODE_COL_AA;
170 i2c_smbus_write_word_data(client, DCON_REG_MODE, dcon->disp_mode);
173 /* Set the scanline to interrupt on during resume */
174 i2c_smbus_write_word_data(client, DCON_REG_SCAN_INT, resumeline);
181 * The smbus doesn't always come back due to what is believed to be
182 * hardware (power rail) bugs. For older models where this is known to
183 * occur, our solution is to attempt to wait for the bus to stabilize;
184 * if it doesn't happen, cut power to the dcon, repower it, and wait
185 * for the bus to stabilize. Rinse, repeat until we have a working
186 * smbus. For newer models, we simply BUG(); we want to know if this
187 * still happens despite the power fixes that have been made!
189 static int dcon_bus_stabilize(struct dcon_priv *dcon, int is_powered_down)
191 unsigned long timeout;
195 if (is_powered_down) {
197 x = olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0);
199 printk(KERN_WARNING "olpc-dcon: unable to force dcon "
200 "to power up: %d!\n", x);
203 msleep(10); /* we'll be conservative */
206 pdata->bus_stabilize_wiggle();
208 for (x = -1, timeout = 50; timeout && x < 0; timeout--) {
210 x = dcon_read(dcon, DCON_REG_ID);
213 printk(KERN_ERR "olpc-dcon: unable to stabilize dcon's "
214 "smbus, reasserting power and praying.\n");
215 BUG_ON(olpc_board_at_least(olpc_board(0xc2)));
217 olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0);
220 goto power_up; /* argh, stupid hardware.. */
224 return dcon_hw_init(dcon, 0);
228 static int dcon_get_backlight(struct dcon_priv *dcon)
230 if (!dcon || !dcon->client)
234 bl_val = dcon_read(dcon, DCON_REG_BRIGHT) & 0x0F;
240 static void dcon_set_backlight_hw(struct dcon_priv *dcon, int level)
242 bl_val = level & 0x0F;
243 dcon_write(dcon, DCON_REG_BRIGHT, bl_val);
245 /* Purposely turn off the backlight when we go to level 0 */
247 dcon->disp_mode &= ~MODE_BL_ENABLE;
248 dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
249 } else if (!(dcon->disp_mode & MODE_BL_ENABLE)) {
250 dcon->disp_mode |= MODE_BL_ENABLE;
251 dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
255 static void dcon_set_backlight(struct dcon_priv *dcon, int level)
257 if (!dcon || !dcon->client)
260 if (bl_val == (level & 0x0F))
263 dcon_set_backlight_hw(dcon, level);
266 /* Set the output type to either color or mono */
267 static int dcon_set_mono_mode(struct dcon_priv *dcon, bool enable_mono)
269 if (dcon->mono == enable_mono)
272 dcon->mono = enable_mono;
275 dcon->disp_mode &= ~(MODE_CSWIZZLE | MODE_COL_AA);
276 dcon->disp_mode |= MODE_MONO_LUMA;
278 dcon->disp_mode &= ~(MODE_MONO_LUMA);
279 dcon->disp_mode |= MODE_CSWIZZLE;
281 dcon->disp_mode |= MODE_COL_AA;
284 dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
288 /* For now, this will be really stupid - we need to address how
289 * DCONLOAD works in a sleep and account for it accordingly
292 static void dcon_sleep(struct dcon_priv *dcon, bool sleep)
296 /* Turn off the backlight and put the DCON to sleep */
298 if (dcon->asleep == sleep)
301 if (!olpc_board_at_least(olpc_board(0xc2)))
306 x = olpc_ec_cmd(0x26, (unsigned char *) &x, 1, NULL, 0);
308 printk(KERN_WARNING "olpc-dcon: unable to force dcon "
309 "to power down: %d!\n", x);
311 dcon->asleep = sleep;
313 /* Only re-enable the backlight if the backlight value is set */
315 dcon->disp_mode |= MODE_BL_ENABLE;
316 x = dcon_bus_stabilize(dcon, 1);
318 printk(KERN_WARNING "olpc-dcon: unable to reinit dcon"
319 " hardware: %d!\n", x);
321 dcon->asleep = sleep;
323 /* Restore backlight */
324 dcon_set_backlight_hw(dcon, bl_val);
327 /* We should turn off some stuff in the framebuffer - but what? */
330 /* the DCON seems to get confused if we change DCONLOAD too
331 * frequently -- i.e., approximately faster than frame time.
332 * normally we don't change it this fast, so in general we won't
335 void dcon_load_holdoff(void)
337 struct timespec delta_t, now;
339 getnstimeofday(&now);
340 delta_t = timespec_sub(now, dcon_load_time);
341 if (delta_t.tv_sec != 0 ||
342 delta_t.tv_nsec > NSEC_PER_MSEC * 20) {
348 /* Set the source of the display (CPU or DCON) */
350 static void dcon_source_switch(struct work_struct *work)
352 struct dcon_priv *dcon = container_of(work, struct dcon_priv,
354 DECLARE_WAITQUEUE(wait, current);
355 int source = dcon_pending;
357 if (dcon_source == source)
365 case DCON_SOURCE_CPU:
366 printk("dcon_source_switch to CPU\n");
367 /* Enable the scanline interrupt bit */
368 if (dcon_write(dcon, DCON_REG_MODE,
369 dcon->disp_mode | MODE_SCAN_INT))
371 "olpc-dcon: couldn't enable scanline interrupt!\n");
373 /* Wait up to one second for the scanline interrupt */
374 wait_event_timeout(dcon_wait_queue,
375 dcon_switched == 1, HZ);
379 printk(KERN_ERR "olpc-dcon: Timeout entering CPU mode; expect a screen glitch.\n");
381 /* Turn off the scanline interrupt */
382 if (dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode))
383 printk(KERN_ERR "olpc-dcon: couldn't disable scanline interrupt!\n");
386 * Ideally we'd like to disable interrupts here so that the
387 * fb unblanking and DCON turn on happen at a known time value;
388 * however, we can't do that right now with fb_blank
389 * messing with semaphores.
391 * For now, we just hope..
394 ignore_fb_events = 1;
395 if (fb_blank(fbinfo, FB_BLANK_UNBLANK)) {
396 ignore_fb_events = 0;
398 printk(KERN_ERR "olpc-dcon: Failed to enter CPU mode\n");
399 dcon_pending = DCON_SOURCE_DCON;
402 ignore_fb_events = 0;
405 /* And turn off the DCON */
406 pdata->set_dconload(1);
407 getnstimeofday(&dcon_load_time);
409 printk(KERN_INFO "olpc-dcon: The CPU has control\n");
411 case DCON_SOURCE_DCON:
414 struct timespec delta_t;
416 printk(KERN_INFO "dcon_source_switch to DCON\n");
418 add_wait_queue(&dcon_wait_queue, &wait);
419 set_current_state(TASK_UNINTERRUPTIBLE);
421 /* Clear DCONLOAD - this implies that the DCON is in control */
422 pdata->set_dconload(0);
423 getnstimeofday(&dcon_load_time);
425 t = schedule_timeout(HZ/2);
426 remove_wait_queue(&dcon_wait_queue, &wait);
427 set_current_state(TASK_RUNNING);
429 if (!dcon_switched) {
430 printk(KERN_ERR "olpc-dcon: Timeout entering DCON mode; expect a screen glitch.\n");
432 /* sometimes the DCON doesn't follow its own rules,
433 * and doesn't wait for two vsync pulses before
434 * ack'ing the frame load with an IRQ. the result
435 * is that the display shows the *previously*
436 * loaded frame. we can detect this by looking at
437 * the time between asserting DCONLOAD and the IRQ --
438 * if it's less than 20msec, then the DCON couldn't
439 * have seen two VSYNC pulses. in that case we
440 * deassert and reassert, and hope for the best.
441 * see http://dev.laptop.org/ticket/9664
443 delta_t = timespec_sub(dcon_irq_time, dcon_load_time);
444 if (dcon_switched && delta_t.tv_sec == 0 &&
445 delta_t.tv_nsec < NSEC_PER_MSEC * 20) {
446 printk(KERN_ERR "olpc-dcon: missed loading, retrying\n");
447 pdata->set_dconload(1);
449 pdata->set_dconload(0);
450 getnstimeofday(&dcon_load_time);
456 ignore_fb_events = 1;
457 if (fb_blank(fbinfo, FB_BLANK_POWERDOWN))
458 printk(KERN_ERR "olpc-dcon: couldn't blank fb!\n");
459 ignore_fb_events = 0;
462 printk(KERN_INFO "olpc-dcon: The DCON has control\n");
469 dcon_source = source;
472 static void dcon_set_source(struct dcon_priv *dcon, int arg)
474 if (dcon_pending == arg)
479 if ((dcon_source != arg) && !work_pending(&dcon->switch_source))
480 schedule_work(&dcon->switch_source);
483 static void dcon_set_source_sync(struct dcon_priv *dcon, int arg)
485 dcon_set_source(dcon, arg);
486 flush_scheduled_work();
489 static int dconbl_set(struct backlight_device *dev)
491 struct dcon_priv *dcon = bl_get_data(dev);
492 int level = dev->props.brightness;
494 if (dev->props.power != FB_BLANK_UNBLANK)
497 dcon_set_backlight(dcon, level);
501 static int dconbl_get(struct backlight_device *dev)
503 struct dcon_priv *dcon = bl_get_data(dev);
504 return dcon_get_backlight(dcon);
507 static ssize_t dcon_mode_show(struct device *dev,
508 struct device_attribute *attr, char *buf)
510 struct dcon_priv *dcon = dev_get_drvdata(dev);
511 return sprintf(buf, "%4.4X\n", dcon->disp_mode);
514 static ssize_t dcon_sleep_show(struct device *dev,
515 struct device_attribute *attr, char *buf)
518 struct dcon_priv *dcon = dev_get_drvdata(dev);
519 return sprintf(buf, "%d\n", dcon->asleep);
522 static ssize_t dcon_freeze_show(struct device *dev,
523 struct device_attribute *attr, char *buf)
525 return sprintf(buf, "%d\n", dcon_source == DCON_SOURCE_DCON ? 1 : 0);
528 static ssize_t dcon_mono_show(struct device *dev,
529 struct device_attribute *attr, char *buf)
531 struct dcon_priv *dcon = dev_get_drvdata(dev);
532 return sprintf(buf, "%d\n", dcon->mono);
535 static ssize_t dcon_resumeline_show(struct device *dev,
536 struct device_attribute *attr, char *buf)
538 return sprintf(buf, "%d\n", resumeline);
541 static int _strtoul(const char *buf, int len, unsigned int *val)
545 unsigned int output = simple_strtoul(buf, &endp, 0);
546 int size = endp - buf;
548 if (*endp && isspace(*endp))
558 static ssize_t dcon_mono_store(struct device *dev,
559 struct device_attribute *attr, const char *buf, size_t count)
564 if (_strtoul(buf, count, &enable_mono))
567 dcon_set_mono_mode(dev_get_drvdata(dev), enable_mono ? true : false);
573 static ssize_t dcon_freeze_store(struct device *dev,
574 struct device_attribute *attr, const char *buf, size_t count)
576 struct dcon_priv *dcon = dev_get_drvdata(dev);
579 if (_strtoul(buf, count, &output))
582 printk(KERN_INFO "dcon_freeze_store: %d\n", output);
586 dcon_set_source(dcon, DCON_SOURCE_CPU);
589 dcon_set_source_sync(dcon, DCON_SOURCE_DCON);
591 case 2: /* normally unused */
592 dcon_set_source(dcon, DCON_SOURCE_DCON);
601 static ssize_t dcon_resumeline_store(struct device *dev,
602 struct device_attribute *attr, const char *buf, size_t count)
607 if (_strtoul(buf, count, &rl))
611 dcon_write(dev_get_drvdata(dev), DCON_REG_SCAN_INT, resumeline);
617 static ssize_t dcon_sleep_store(struct device *dev,
618 struct device_attribute *attr, const char *buf, size_t count)
622 if (_strtoul(buf, count, &output))
625 dcon_sleep(dev_get_drvdata(dev), output ? true : false);
629 static struct device_attribute dcon_device_files[] = {
630 __ATTR(mode, 0444, dcon_mode_show, NULL),
631 __ATTR(sleep, 0644, dcon_sleep_show, dcon_sleep_store),
632 __ATTR(freeze, 0644, dcon_freeze_show, dcon_freeze_store),
633 __ATTR(monochrome, 0644, dcon_mono_show, dcon_mono_store),
634 __ATTR(resumeline, 0644, dcon_resumeline_show, dcon_resumeline_store),
637 static const struct backlight_ops dcon_bl_ops = {
638 .get_brightness = dconbl_get,
639 .update_status = dconbl_set
643 static int dcon_reboot_notify(struct notifier_block *nb,
644 unsigned long foo, void *bar)
646 struct dcon_priv *dcon = container_of(nb, struct dcon_priv, reboot_nb);
648 if (!dcon || !dcon->client)
651 /* Turn off the DCON. Entirely. */
652 dcon_write(dcon, DCON_REG_MODE, 0x39);
653 dcon_write(dcon, DCON_REG_MODE, 0x32);
657 static int unfreeze_on_panic(struct notifier_block *nb,
658 unsigned long e, void *p)
660 pdata->set_dconload(1);
664 static struct notifier_block dcon_panic_nb = {
665 .notifier_call = unfreeze_on_panic,
669 * When the framebuffer sleeps due to external sources (e.g. user idle), power
670 * down the DCON as well. Power it back up when the fb comes back to life.
672 static int fb_notifier_callback(struct notifier_block *self,
673 unsigned long event, void *data)
675 struct fb_event *evdata = data;
676 struct backlight_device *bl = container_of(self,
677 struct backlight_device, fb_notif);
678 struct dcon_priv *dcon = bl_get_data(bl);
679 int *blank = (int *) evdata->data;
680 if (((event != FB_EVENT_BLANK) && (event != FB_EVENT_CONBLANK)) ||
683 dcon_sleep(dcon, *blank ? true : false);
687 static struct notifier_block fb_nb = {
688 .notifier_call = fb_notifier_callback,
691 static int dcon_detect(struct i2c_client *client, struct i2c_board_info *info)
693 strlcpy(info->type, "olpc_dcon", I2C_NAME_SIZE);
698 static int dcon_probe(struct i2c_client *client, const struct i2c_device_id *id)
700 struct dcon_priv *dcon;
703 dcon = kzalloc(sizeof(*dcon), GFP_KERNEL);
707 dcon->client = client;
708 INIT_WORK(&dcon->switch_source, dcon_source_switch);
709 dcon->reboot_nb.notifier_call = dcon_reboot_notify;
710 dcon->reboot_nb.priority = -1;
712 i2c_set_clientdata(client, dcon);
714 if (num_registered_fb >= 1)
715 fbinfo = registered_fb[0];
717 rc = dcon_hw_init(dcon, 1);
721 /* Add the DCON device */
723 dcon_device = platform_device_alloc("dcon", -1);
725 if (dcon_device == NULL) {
726 printk(KERN_ERR "dcon: Unable to create the DCON device\n");
730 rc = platform_device_add(dcon_device);
731 platform_set_drvdata(dcon_device, dcon);
734 printk(KERN_ERR "dcon: Unable to add the DCON device\n");
738 for (i = 0; i < ARRAY_SIZE(dcon_device_files); i++) {
739 rc = device_create_file(&dcon_device->dev,
740 &dcon_device_files[i]);
742 dev_err(&dcon_device->dev, "Cannot create sysfs file\n");
747 /* Add the backlight device for the DCON */
748 dcon_bl_dev = backlight_device_register("dcon-bl", &dcon_device->dev,
749 dcon, &dcon_bl_ops, NULL);
751 if (IS_ERR(dcon_bl_dev)) {
752 printk(KERN_ERR "Cannot register the backlight device (%ld)\n",
753 PTR_ERR(dcon_bl_dev));
756 dcon_bl_dev->props.max_brightness = 15;
757 dcon_bl_dev->props.power = FB_BLANK_UNBLANK;
758 dcon_bl_dev->props.brightness = dcon_get_backlight(dcon);
760 backlight_update_status(dcon_bl_dev);
763 register_reboot_notifier(&dcon->reboot_nb);
764 atomic_notifier_chain_register(&panic_notifier_list, &dcon_panic_nb);
765 fb_register_client(&fb_nb);
770 for (j = 0; j < i; j++)
771 device_remove_file(&dcon_device->dev, &dcon_device_files[j]);
773 platform_device_unregister(dcon_device);
776 free_irq(DCON_IRQ, &dcon_driver);
778 i2c_set_clientdata(client, NULL);
783 static int dcon_remove(struct i2c_client *client)
785 struct dcon_priv *dcon = i2c_get_clientdata(client);
787 i2c_set_clientdata(client, NULL);
789 fb_unregister_client(&fb_nb);
790 unregister_reboot_notifier(&dcon->reboot_nb);
791 atomic_notifier_chain_unregister(&panic_notifier_list, &dcon_panic_nb);
793 free_irq(DCON_IRQ, &dcon_driver);
795 if (dcon_bl_dev != NULL)
796 backlight_device_unregister(dcon_bl_dev);
798 if (dcon_device != NULL)
799 platform_device_unregister(dcon_device);
800 cancel_work_sync(&dcon->switch_source);
808 static int dcon_suspend(struct i2c_client *client, pm_message_t state)
810 struct dcon_priv *dcon = i2c_get_clientdata(client);
813 /* Set up the DCON to have the source */
814 dcon_set_source_sync(dcon, DCON_SOURCE_DCON);
820 static int dcon_resume(struct i2c_client *client)
822 struct dcon_priv *dcon = i2c_get_clientdata(client);
825 dcon_bus_stabilize(dcon, 0);
826 dcon_set_source(dcon, DCON_SOURCE_CPU);
835 static irqreturn_t dcon_interrupt(int irq, void *id)
837 int status = pdata->read_status();
842 switch (status & 3) {
844 printk(KERN_DEBUG "olpc-dcon: DCONLOAD_MISSED interrupt\n");
847 case 2: /* switch to DCON mode */
848 case 1: /* switch to CPU mode */
850 getnstimeofday(&dcon_irq_time);
851 wake_up(&dcon_wait_queue);
855 /* workaround resume case: the DCON (on 1.5) doesn't
856 * ever assert status 0x01 when switching to CPU mode
857 * during resume. this is because DCONLOAD is de-asserted
858 * _immediately_ upon exiting S3, so the actual release
859 * of the DCON happened long before this point.
860 * see http://dev.laptop.org/ticket/9869
862 if (dcon_source != dcon_pending && !dcon_switched) {
864 getnstimeofday(&dcon_irq_time);
865 wake_up(&dcon_wait_queue);
866 printk(KERN_DEBUG "olpc-dcon: switching w/ status 0/0\n");
868 printk(KERN_DEBUG "olpc-dcon: scanline interrupt w/CPU\n");
875 static const struct i2c_device_id dcon_idtable[] = {
880 MODULE_DEVICE_TABLE(i2c, dcon_idtable);
882 static struct i2c_driver dcon_driver = {
886 .class = I2C_CLASS_DDC | I2C_CLASS_HWMON,
887 .id_table = dcon_idtable,
889 .remove = __devexit_p(dcon_remove),
890 .detect = dcon_detect,
891 .address_list = normal_i2c,
893 .suspend = dcon_suspend,
894 .resume = dcon_resume,
898 #include "olpc_dcon_xo_1.c"
900 static int __init olpc_dcon_init(void)
902 pdata = &dcon_pdata_xo_1;
904 return i2c_add_driver(&dcon_driver);
907 static void __exit olpc_dcon_exit(void)
909 i2c_del_driver(&dcon_driver);
912 module_init(olpc_dcon_init);
913 module_exit(olpc_dcon_exit);
915 MODULE_LICENSE("GPL");