Version:  2.0.40 2.2.26 2.4.37 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18

Linux/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) 2010-2011  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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 15 
 16 #include <linux/kernel.h>
 17 #include <linux/fb.h>
 18 #include <linux/console.h>
 19 #include <linux/i2c.h>
 20 #include <linux/platform_device.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/module.h>
 26 #include <linux/backlight.h>
 27 #include <linux/device.h>
 28 #include <linux/uaccess.h>
 29 #include <linux/ctype.h>
 30 #include <linux/reboot.h>
 31 #include <linux/olpc-ec.h>
 32 #include <asm/tsc.h>
 33 #include <asm/olpc.h>
 34 
 35 #include "olpc_dcon.h"
 36 
 37 /* Module definitions */
 38 
 39 static ushort resumeline = 898;
 40 module_param(resumeline, ushort, 0444);
 41 
 42 static struct dcon_platform_data *pdata;
 43 
 44 /* I2C structures */
 45 
 46 /* Platform devices */
 47 static struct platform_device *dcon_device;
 48 
 49 static unsigned short normal_i2c[] = { 0x0d, I2C_CLIENT_END };
 50 
 51 static s32 dcon_write(struct dcon_priv *dcon, u8 reg, u16 val)
 52 {
 53         return i2c_smbus_write_word_data(dcon->client, reg, val);
 54 }
 55 
 56 static s32 dcon_read(struct dcon_priv *dcon, u8 reg)
 57 {
 58         return i2c_smbus_read_word_data(dcon->client, reg);
 59 }
 60 
 61 /* ===== API functions - these are called by a variety of users ==== */
 62 
 63 static int dcon_hw_init(struct dcon_priv *dcon, int is_init)
 64 {
 65         uint16_t ver;
 66         int rc = 0;
 67 
 68         ver = dcon_read(dcon, DCON_REG_ID);
 69         if ((ver >> 8) != 0xDC) {
 70                 pr_err("DCON ID not 0xDCxx: 0x%04x instead.\n", ver);
 71                 rc = -ENXIO;
 72                 goto err;
 73         }
 74 
 75         if (is_init) {
 76                 pr_info("Discovered DCON version %x\n", ver & 0xFF);
 77                 rc = pdata->init(dcon);
 78                 if (rc != 0) {
 79                         pr_err("Unable to init.\n");
 80                         goto err;
 81                 }
 82         }
 83 
 84         if (ver < 0xdc02) {
 85                 dev_err(&dcon->client->dev,
 86                                 "DCON v1 is unsupported, giving up..\n");
 87                 rc = -ENODEV;
 88                 goto err;
 89         }
 90 
 91         /* SDRAM setup/hold time */
 92         dcon_write(dcon, 0x3a, 0xc040);
 93         dcon_write(dcon, DCON_REG_MEM_OPT_A, 0x0000);  /* clear option bits */
 94         dcon_write(dcon, DCON_REG_MEM_OPT_A,
 95                                 MEM_DLL_CLOCK_DELAY | MEM_POWER_DOWN);
 96         dcon_write(dcon, DCON_REG_MEM_OPT_B, MEM_SOFT_RESET);
 97 
 98         /* Colour swizzle, AA, no passthrough, backlight */
 99         if (is_init) {
100                 dcon->disp_mode = MODE_PASSTHRU | MODE_BL_ENABLE |
101                                 MODE_CSWIZZLE | MODE_COL_AA;
102         }
103         dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
104 
105 
106         /* Set the scanline to interrupt on during resume */
107         dcon_write(dcon, DCON_REG_SCAN_INT, resumeline);
108 
109 err:
110         return rc;
111 }
112 
113 /*
114  * The smbus doesn't always come back due to what is believed to be
115  * hardware (power rail) bugs.  For older models where this is known to
116  * occur, our solution is to attempt to wait for the bus to stabilize;
117  * if it doesn't happen, cut power to the dcon, repower it, and wait
118  * for the bus to stabilize.  Rinse, repeat until we have a working
119  * smbus.  For newer models, we simply BUG(); we want to know if this
120  * still happens despite the power fixes that have been made!
121  */
122 static int dcon_bus_stabilize(struct dcon_priv *dcon, int is_powered_down)
123 {
124         unsigned long timeout;
125         u8 pm;
126         int x;
127 
128 power_up:
129         if (is_powered_down) {
130                 pm = 1;
131                 x = olpc_ec_cmd(EC_DCON_POWER_MODE, &pm, 1, NULL, 0);
132                 if (x) {
133                         pr_warn("unable to force dcon to power up: %d!\n", x);
134                         return x;
135                 }
136                 usleep_range(10000, 11000);  /* we'll be conservative */
137         }
138 
139         pdata->bus_stabilize_wiggle();
140 
141         for (x = -1, timeout = 50; timeout && x < 0; timeout--) {
142                 usleep_range(1000, 1100);
143                 x = dcon_read(dcon, DCON_REG_ID);
144         }
145         if (x < 0) {
146                 pr_err("unable to stabilize dcon's smbus, reasserting power and praying.\n");
147                 BUG_ON(olpc_board_at_least(olpc_board(0xc2)));
148                 pm = 0;
149                 olpc_ec_cmd(EC_DCON_POWER_MODE, &pm, 1, NULL, 0);
150                 msleep(100);
151                 is_powered_down = 1;
152                 goto power_up;  /* argh, stupid hardware.. */
153         }
154 
155         if (is_powered_down)
156                 return dcon_hw_init(dcon, 0);
157         return 0;
158 }
159 
160 static void dcon_set_backlight(struct dcon_priv *dcon, u8 level)
161 {
162         dcon->bl_val = level;
163         dcon_write(dcon, DCON_REG_BRIGHT, dcon->bl_val);
164 
165         /* Purposely turn off the backlight when we go to level 0 */
166         if (dcon->bl_val == 0) {
167                 dcon->disp_mode &= ~MODE_BL_ENABLE;
168                 dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
169         } else if (!(dcon->disp_mode & MODE_BL_ENABLE)) {
170                 dcon->disp_mode |= MODE_BL_ENABLE;
171                 dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
172         }
173 }
174 
175 /* Set the output type to either color or mono */
176 static int dcon_set_mono_mode(struct dcon_priv *dcon, bool enable_mono)
177 {
178         if (dcon->mono == enable_mono)
179                 return 0;
180 
181         dcon->mono = enable_mono;
182 
183         if (enable_mono) {
184                 dcon->disp_mode &= ~(MODE_CSWIZZLE | MODE_COL_AA);
185                 dcon->disp_mode |= MODE_MONO_LUMA;
186         } else {
187                 dcon->disp_mode &= ~(MODE_MONO_LUMA);
188                 dcon->disp_mode |= MODE_CSWIZZLE | MODE_COL_AA;
189         }
190 
191         dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
192         return 0;
193 }
194 
195 /* For now, this will be really stupid - we need to address how
196  * DCONLOAD works in a sleep and account for it accordingly
197  */
198 
199 static void dcon_sleep(struct dcon_priv *dcon, bool sleep)
200 {
201         int x;
202 
203         /* Turn off the backlight and put the DCON to sleep */
204 
205         if (dcon->asleep == sleep)
206                 return;
207 
208         if (!olpc_board_at_least(olpc_board(0xc2)))
209                 return;
210 
211         if (sleep) {
212                 u8 pm = 0;
213 
214                 x = olpc_ec_cmd(EC_DCON_POWER_MODE, &pm, 1, NULL, 0);
215                 if (x)
216                         pr_warn("unable to force dcon to power down: %d!\n", x);
217                 else
218                         dcon->asleep = sleep;
219         } else {
220                 /* Only re-enable the backlight if the backlight value is set */
221                 if (dcon->bl_val != 0)
222                         dcon->disp_mode |= MODE_BL_ENABLE;
223                 x = dcon_bus_stabilize(dcon, 1);
224                 if (x)
225                         pr_warn("unable to reinit dcon hardware: %d!\n", x);
226                 else
227                         dcon->asleep = sleep;
228 
229                 /* Restore backlight */
230                 dcon_set_backlight(dcon, dcon->bl_val);
231         }
232 
233         /* We should turn off some stuff in the framebuffer - but what? */
234 }
235 
236 /* the DCON seems to get confused if we change DCONLOAD too
237  * frequently -- i.e., approximately faster than frame time.
238  * normally we don't change it this fast, so in general we won't
239  * delay here.
240  */
241 static void dcon_load_holdoff(struct dcon_priv *dcon)
242 {
243         struct timespec delta_t, now;
244 
245         while (1) {
246                 getnstimeofday(&now);
247                 delta_t = timespec_sub(now, dcon->load_time);
248                 if (delta_t.tv_sec != 0 ||
249                         delta_t.tv_nsec > NSEC_PER_MSEC * 20) {
250                         break;
251                 }
252                 mdelay(4);
253         }
254 }
255 
256 static bool dcon_blank_fb(struct dcon_priv *dcon, bool blank)
257 {
258         int err;
259 
260         console_lock();
261         if (!lock_fb_info(dcon->fbinfo)) {
262                 console_unlock();
263                 dev_err(&dcon->client->dev, "unable to lock framebuffer\n");
264                 return false;
265         }
266 
267         dcon->ignore_fb_events = true;
268         err = fb_blank(dcon->fbinfo,
269                         blank ? FB_BLANK_POWERDOWN : FB_BLANK_UNBLANK);
270         dcon->ignore_fb_events = false;
271         unlock_fb_info(dcon->fbinfo);
272         console_unlock();
273 
274         if (err) {
275                 dev_err(&dcon->client->dev, "couldn't %sblank framebuffer\n",
276                                 blank ? "" : "un");
277                 return false;
278         }
279         return true;
280 }
281 
282 /* Set the source of the display (CPU or DCON) */
283 static void dcon_source_switch(struct work_struct *work)
284 {
285         struct dcon_priv *dcon = container_of(work, struct dcon_priv,
286                         switch_source);
287         int source = dcon->pending_src;
288 
289         if (dcon->curr_src == source)
290                 return;
291 
292         dcon_load_holdoff(dcon);
293 
294         dcon->switched = false;
295 
296         switch (source) {
297         case DCON_SOURCE_CPU:
298                 pr_info("dcon_source_switch to CPU\n");
299                 /* Enable the scanline interrupt bit */
300                 if (dcon_write(dcon, DCON_REG_MODE,
301                                 dcon->disp_mode | MODE_SCAN_INT))
302                         pr_err("couldn't enable scanline interrupt!\n");
303                 else
304                         /* Wait up to one second for the scanline interrupt */
305                         wait_event_timeout(dcon->waitq, dcon->switched, HZ);
306 
307                 if (!dcon->switched)
308                         pr_err("Timeout entering CPU mode; expect a screen glitch.\n");
309 
310                 /* Turn off the scanline interrupt */
311                 if (dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode))
312                         pr_err("couldn't disable scanline interrupt!\n");
313 
314                 /*
315                  * Ideally we'd like to disable interrupts here so that the
316                  * fb unblanking and DCON turn on happen at a known time value;
317                  * however, we can't do that right now with fb_blank
318                  * messing with semaphores.
319                  *
320                  * For now, we just hope..
321                  */
322                 if (!dcon_blank_fb(dcon, false)) {
323                         pr_err("Failed to enter CPU mode\n");
324                         dcon->pending_src = DCON_SOURCE_DCON;
325                         return;
326                 }
327 
328                 /* And turn off the DCON */
329                 pdata->set_dconload(1);
330                 getnstimeofday(&dcon->load_time);
331 
332                 pr_info("The CPU has control\n");
333                 break;
334         case DCON_SOURCE_DCON:
335         {
336                 struct timespec delta_t;
337 
338                 pr_info("dcon_source_switch to DCON\n");
339 
340                 /* Clear DCONLOAD - this implies that the DCON is in control */
341                 pdata->set_dconload(0);
342                 getnstimeofday(&dcon->load_time);
343 
344                 wait_event_timeout(dcon->waitq, dcon->switched, HZ/2);
345 
346                 if (!dcon->switched) {
347                         pr_err("Timeout entering DCON mode; expect a screen glitch.\n");
348                 } else {
349                         /* sometimes the DCON doesn't follow its own rules,
350                          * and doesn't wait for two vsync pulses before
351                          * ack'ing the frame load with an IRQ.  the result
352                          * is that the display shows the *previously*
353                          * loaded frame.  we can detect this by looking at
354                          * the time between asserting DCONLOAD and the IRQ --
355                          * if it's less than 20msec, then the DCON couldn't
356                          * have seen two VSYNC pulses.  in that case we
357                          * deassert and reassert, and hope for the best.
358                          * see http://dev.laptop.org/ticket/9664
359                          */
360                         delta_t = timespec_sub(dcon->irq_time, dcon->load_time);
361                         if (dcon->switched && delta_t.tv_sec == 0 &&
362                                         delta_t.tv_nsec < NSEC_PER_MSEC * 20) {
363                                 pr_err("missed loading, retrying\n");
364                                 pdata->set_dconload(1);
365                                 mdelay(41);
366                                 pdata->set_dconload(0);
367                                 getnstimeofday(&dcon->load_time);
368                                 mdelay(41);
369                         }
370                 }
371 
372                 dcon_blank_fb(dcon, true);
373                 pr_info("The DCON has control\n");
374                 break;
375         }
376         default:
377                 BUG();
378         }
379 
380         dcon->curr_src = source;
381 }
382 
383 static void dcon_set_source(struct dcon_priv *dcon, int arg)
384 {
385         if (dcon->pending_src == arg)
386                 return;
387 
388         dcon->pending_src = arg;
389 
390         if (dcon->curr_src != arg)
391                 schedule_work(&dcon->switch_source);
392 }
393 
394 static void dcon_set_source_sync(struct dcon_priv *dcon, int arg)
395 {
396         dcon_set_source(dcon, arg);
397         flush_scheduled_work();
398 }
399 
400 static ssize_t dcon_mode_show(struct device *dev,
401         struct device_attribute *attr, char *buf)
402 {
403         struct dcon_priv *dcon = dev_get_drvdata(dev);
404 
405         return sprintf(buf, "%4.4X\n", dcon->disp_mode);
406 }
407 
408 static ssize_t dcon_sleep_show(struct device *dev,
409         struct device_attribute *attr, char *buf)
410 {
411         struct dcon_priv *dcon = dev_get_drvdata(dev);
412 
413         return sprintf(buf, "%d\n", dcon->asleep);
414 }
415 
416 static ssize_t dcon_freeze_show(struct device *dev,
417         struct device_attribute *attr, char *buf)
418 {
419         struct dcon_priv *dcon = dev_get_drvdata(dev);
420 
421         return sprintf(buf, "%d\n", dcon->curr_src == DCON_SOURCE_DCON ? 1 : 0);
422 }
423 
424 static ssize_t dcon_mono_show(struct device *dev,
425         struct device_attribute *attr, char *buf)
426 {
427         struct dcon_priv *dcon = dev_get_drvdata(dev);
428 
429         return sprintf(buf, "%d\n", dcon->mono);
430 }
431 
432 static ssize_t dcon_resumeline_show(struct device *dev,
433         struct device_attribute *attr, char *buf)
434 {
435         return sprintf(buf, "%d\n", resumeline);
436 }
437 
438 static ssize_t dcon_mono_store(struct device *dev,
439         struct device_attribute *attr, const char *buf, size_t count)
440 {
441         unsigned long enable_mono;
442         int rc;
443 
444         rc = kstrtoul(buf, 10, &enable_mono);
445         if (rc)
446                 return rc;
447 
448         dcon_set_mono_mode(dev_get_drvdata(dev), enable_mono ? true : false);
449 
450         return count;
451 }
452 
453 static ssize_t dcon_freeze_store(struct device *dev,
454         struct device_attribute *attr, const char *buf, size_t count)
455 {
456         struct dcon_priv *dcon = dev_get_drvdata(dev);
457         unsigned long output;
458         int ret;
459 
460         ret = kstrtoul(buf, 10, &output);
461         if (ret)
462                 return ret;
463 
464         pr_info("dcon_freeze_store: %lu\n", output);
465 
466         switch (output) {
467         case 0:
468                 dcon_set_source(dcon, DCON_SOURCE_CPU);
469                 break;
470         case 1:
471                 dcon_set_source_sync(dcon, DCON_SOURCE_DCON);
472                 break;
473         case 2:  /* normally unused */
474                 dcon_set_source(dcon, DCON_SOURCE_DCON);
475                 break;
476         default:
477                 return -EINVAL;
478         }
479 
480         return count;
481 }
482 
483 static ssize_t dcon_resumeline_store(struct device *dev,
484         struct device_attribute *attr, const char *buf, size_t count)
485 {
486         unsigned short rl;
487         int rc;
488 
489         rc = kstrtou16(buf, 10, &rl);
490         if (rc)
491                 return rc;
492 
493         resumeline = rl;
494         dcon_write(dev_get_drvdata(dev), DCON_REG_SCAN_INT, resumeline);
495 
496         return count;
497 }
498 
499 static ssize_t dcon_sleep_store(struct device *dev,
500         struct device_attribute *attr, const char *buf, size_t count)
501 {
502         unsigned long output;
503         int ret;
504 
505         ret = kstrtoul(buf, 10, &output);
506         if (ret)
507                 return ret;
508 
509         dcon_sleep(dev_get_drvdata(dev), output ? true : false);
510         return count;
511 }
512 
513 static struct device_attribute dcon_device_files[] = {
514         __ATTR(mode, 0444, dcon_mode_show, NULL),
515         __ATTR(sleep, 0644, dcon_sleep_show, dcon_sleep_store),
516         __ATTR(freeze, 0644, dcon_freeze_show, dcon_freeze_store),
517         __ATTR(monochrome, 0644, dcon_mono_show, dcon_mono_store),
518         __ATTR(resumeline, 0644, dcon_resumeline_show, dcon_resumeline_store),
519 };
520 
521 static int dcon_bl_update(struct backlight_device *dev)
522 {
523         struct dcon_priv *dcon = bl_get_data(dev);
524         u8 level = dev->props.brightness & 0x0F;
525 
526         if (dev->props.power != FB_BLANK_UNBLANK)
527                 level = 0;
528 
529         if (level != dcon->bl_val)
530                 dcon_set_backlight(dcon, level);
531 
532         /* power down the DCON when the screen is blanked */
533         if (!dcon->ignore_fb_events)
534                 dcon_sleep(dcon, !!(dev->props.state & BL_CORE_FBBLANK));
535 
536         return 0;
537 }
538 
539 static int dcon_bl_get(struct backlight_device *dev)
540 {
541         struct dcon_priv *dcon = bl_get_data(dev);
542 
543         return dcon->bl_val;
544 }
545 
546 static const struct backlight_ops dcon_bl_ops = {
547         .update_status = dcon_bl_update,
548         .get_brightness = dcon_bl_get,
549 };
550 
551 static struct backlight_properties dcon_bl_props = {
552         .max_brightness = 15,
553         .type = BACKLIGHT_RAW,
554         .power = FB_BLANK_UNBLANK,
555 };
556 
557 static int dcon_reboot_notify(struct notifier_block *nb,
558                               unsigned long foo, void *bar)
559 {
560         struct dcon_priv *dcon = container_of(nb, struct dcon_priv, reboot_nb);
561 
562         if (!dcon || !dcon->client)
563                 return NOTIFY_DONE;
564 
565         /* Turn off the DCON. Entirely. */
566         dcon_write(dcon, DCON_REG_MODE, 0x39);
567         dcon_write(dcon, DCON_REG_MODE, 0x32);
568         return NOTIFY_DONE;
569 }
570 
571 static int unfreeze_on_panic(struct notifier_block *nb,
572                              unsigned long e, void *p)
573 {
574         pdata->set_dconload(1);
575         return NOTIFY_DONE;
576 }
577 
578 static struct notifier_block dcon_panic_nb = {
579         .notifier_call = unfreeze_on_panic,
580 };
581 
582 static int dcon_detect(struct i2c_client *client, struct i2c_board_info *info)
583 {
584         strlcpy(info->type, "olpc_dcon", I2C_NAME_SIZE);
585 
586         return 0;
587 }
588 
589 static int dcon_probe(struct i2c_client *client, const struct i2c_device_id *id)
590 {
591         struct dcon_priv *dcon;
592         int rc, i, j;
593 
594         if (!pdata)
595                 return -ENXIO;
596 
597         dcon = kzalloc(sizeof(*dcon), GFP_KERNEL);
598         if (!dcon)
599                 return -ENOMEM;
600 
601         dcon->client = client;
602         init_waitqueue_head(&dcon->waitq);
603         INIT_WORK(&dcon->switch_source, dcon_source_switch);
604         dcon->reboot_nb.notifier_call = dcon_reboot_notify;
605         dcon->reboot_nb.priority = -1;
606 
607         i2c_set_clientdata(client, dcon);
608 
609         if (num_registered_fb < 1) {
610                 dev_err(&client->dev, "DCON driver requires a registered fb\n");
611                 rc = -EIO;
612                 goto einit;
613         }
614         dcon->fbinfo = registered_fb[0];
615 
616         rc = dcon_hw_init(dcon, 1);
617         if (rc)
618                 goto einit;
619 
620         /* Add the DCON device */
621 
622         dcon_device = platform_device_alloc("dcon", -1);
623 
624         if (dcon_device == NULL) {
625                 pr_err("Unable to create the DCON device\n");
626                 rc = -ENOMEM;
627                 goto eirq;
628         }
629         rc = platform_device_add(dcon_device);
630         platform_set_drvdata(dcon_device, dcon);
631 
632         if (rc) {
633                 pr_err("Unable to add the DCON device\n");
634                 goto edev;
635         }
636 
637         for (i = 0; i < ARRAY_SIZE(dcon_device_files); i++) {
638                 rc = device_create_file(&dcon_device->dev,
639                                         &dcon_device_files[i]);
640                 if (rc) {
641                         dev_err(&dcon_device->dev, "Cannot create sysfs file\n");
642                         goto ecreate;
643                 }
644         }
645 
646         dcon->bl_val = dcon_read(dcon, DCON_REG_BRIGHT) & 0x0F;
647 
648         /* Add the backlight device for the DCON */
649         dcon_bl_props.brightness = dcon->bl_val;
650         dcon->bl_dev = backlight_device_register("dcon-bl", &dcon_device->dev,
651                 dcon, &dcon_bl_ops, &dcon_bl_props);
652         if (IS_ERR(dcon->bl_dev)) {
653                 dev_err(&client->dev, "cannot register backlight dev (%ld)\n",
654                                 PTR_ERR(dcon->bl_dev));
655                 dcon->bl_dev = NULL;
656         }
657 
658         register_reboot_notifier(&dcon->reboot_nb);
659         atomic_notifier_chain_register(&panic_notifier_list, &dcon_panic_nb);
660 
661         return 0;
662 
663  ecreate:
664         for (j = 0; j < i; j++)
665                 device_remove_file(&dcon_device->dev, &dcon_device_files[j]);
666  edev:
667         platform_device_unregister(dcon_device);
668         dcon_device = NULL;
669  eirq:
670         free_irq(DCON_IRQ, dcon);
671  einit:
672         kfree(dcon);
673         return rc;
674 }
675 
676 static int dcon_remove(struct i2c_client *client)
677 {
678         struct dcon_priv *dcon = i2c_get_clientdata(client);
679 
680         unregister_reboot_notifier(&dcon->reboot_nb);
681         atomic_notifier_chain_unregister(&panic_notifier_list, &dcon_panic_nb);
682 
683         free_irq(DCON_IRQ, dcon);
684 
685         if (dcon->bl_dev)
686                 backlight_device_unregister(dcon->bl_dev);
687 
688         if (dcon_device != NULL)
689                 platform_device_unregister(dcon_device);
690         cancel_work_sync(&dcon->switch_source);
691 
692         kfree(dcon);
693 
694         return 0;
695 }
696 
697 #ifdef CONFIG_PM
698 static int dcon_suspend(struct device *dev)
699 {
700         struct i2c_client *client = to_i2c_client(dev);
701         struct dcon_priv *dcon = i2c_get_clientdata(client);
702 
703         if (!dcon->asleep) {
704                 /* Set up the DCON to have the source */
705                 dcon_set_source_sync(dcon, DCON_SOURCE_DCON);
706         }
707 
708         return 0;
709 }
710 
711 static int dcon_resume(struct device *dev)
712 {
713         struct i2c_client *client = to_i2c_client(dev);
714         struct dcon_priv *dcon = i2c_get_clientdata(client);
715 
716         if (!dcon->asleep) {
717                 dcon_bus_stabilize(dcon, 0);
718                 dcon_set_source(dcon, DCON_SOURCE_CPU);
719         }
720 
721         return 0;
722 }
723 
724 #else
725 
726 #define dcon_suspend NULL
727 #define dcon_resume NULL
728 
729 #endif /* CONFIG_PM */
730 
731 
732 irqreturn_t dcon_interrupt(int irq, void *id)
733 {
734         struct dcon_priv *dcon = id;
735         u8 status;
736 
737         if (pdata->read_status(&status))
738                 return IRQ_NONE;
739 
740         switch (status & 3) {
741         case 3:
742                 pr_debug("DCONLOAD_MISSED interrupt\n");
743                 break;
744 
745         case 2: /* switch to DCON mode */
746         case 1: /* switch to CPU mode */
747                 dcon->switched = true;
748                 getnstimeofday(&dcon->irq_time);
749                 wake_up(&dcon->waitq);
750                 break;
751 
752         case 0:
753                 /* workaround resume case:  the DCON (on 1.5) doesn't
754                  * ever assert status 0x01 when switching to CPU mode
755                  * during resume.  this is because DCONLOAD is de-asserted
756                  * _immediately_ upon exiting S3, so the actual release
757                  * of the DCON happened long before this point.
758                  * see http://dev.laptop.org/ticket/9869
759                  */
760                 if (dcon->curr_src != dcon->pending_src && !dcon->switched) {
761                         dcon->switched = true;
762                         getnstimeofday(&dcon->irq_time);
763                         wake_up(&dcon->waitq);
764                         pr_debug("switching w/ status 0/0\n");
765                 } else {
766                         pr_debug("scanline interrupt w/CPU\n");
767                 }
768         }
769 
770         return IRQ_HANDLED;
771 }
772 
773 static const struct dev_pm_ops dcon_pm_ops = {
774         .suspend = dcon_suspend,
775         .resume = dcon_resume,
776 };
777 
778 static const struct i2c_device_id dcon_idtable[] = {
779         { "olpc_dcon",  0 },
780         { }
781 };
782 MODULE_DEVICE_TABLE(i2c, dcon_idtable);
783 
784 struct i2c_driver dcon_driver = {
785         .driver = {
786                 .name   = "olpc_dcon",
787                 .pm = &dcon_pm_ops,
788         },
789         .class = I2C_CLASS_DDC | I2C_CLASS_HWMON,
790         .id_table = dcon_idtable,
791         .probe = dcon_probe,
792         .remove = dcon_remove,
793         .detect = dcon_detect,
794         .address_list = normal_i2c,
795 };
796 
797 static int __init olpc_dcon_init(void)
798 {
799 #ifdef CONFIG_FB_OLPC_DCON_1_5
800         /* XO-1.5 */
801         if (olpc_board_at_least(olpc_board(0xd0)))
802                 pdata = &dcon_pdata_xo_1_5;
803 #endif
804 #ifdef CONFIG_FB_OLPC_DCON_1
805         if (!pdata)
806                 pdata = &dcon_pdata_xo_1;
807 #endif
808 
809         return i2c_add_driver(&dcon_driver);
810 }
811 
812 static void __exit olpc_dcon_exit(void)
813 {
814         i2c_del_driver(&dcon_driver);
815 }
816 
817 module_init(olpc_dcon_init);
818 module_exit(olpc_dcon_exit);
819 
820 MODULE_LICENSE("GPL");
821 

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