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11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13#include <linux/kernel.h>
14#include <linux/fb.h>
15#include <linux/console.h>
16#include <linux/i2c.h>
17#include <linux/platform_device.h>
18#include <linux/interrupt.h>
19#include <linux/delay.h>
20#include <linux/module.h>
21#include <linux/backlight.h>
22#include <linux/device.h>
23#include <linux/uaccess.h>
24#include <linux/ctype.h>
25#include <linux/panic_notifier.h>
26#include <linux/reboot.h>
27#include <linux/olpc-ec.h>
28#include <asm/tsc.h>
29#include <asm/olpc.h>
30
31#include "olpc_dcon.h"
32
33
34
35static ushort resumeline = 898;
36module_param(resumeline, ushort, 0444);
37
38static struct dcon_platform_data *pdata;
39
40
41
42
43static struct platform_device *dcon_device;
44
45static unsigned short normal_i2c[] = { 0x0d, I2C_CLIENT_END };
46
47static s32 dcon_write(struct dcon_priv *dcon, u8 reg, u16 val)
48{
49 return i2c_smbus_write_word_data(dcon->client, reg, val);
50}
51
52static s32 dcon_read(struct dcon_priv *dcon, u8 reg)
53{
54 return i2c_smbus_read_word_data(dcon->client, reg);
55}
56
57
58
59static int dcon_hw_init(struct dcon_priv *dcon, int is_init)
60{
61 u16 ver;
62 int rc = 0;
63
64 ver = dcon_read(dcon, DCON_REG_ID);
65 if ((ver >> 8) != 0xDC) {
66 pr_err("DCON ID not 0xDCxx: 0x%04x instead.\n", ver);
67 rc = -ENXIO;
68 goto err;
69 }
70
71 if (is_init) {
72 pr_info("Discovered DCON version %x\n", ver & 0xFF);
73 rc = pdata->init(dcon);
74 if (rc != 0) {
75 pr_err("Unable to init.\n");
76 goto err;
77 }
78 }
79
80 if (ver < 0xdc02) {
81 dev_err(&dcon->client->dev,
82 "DCON v1 is unsupported, giving up..\n");
83 rc = -ENODEV;
84 goto err;
85 }
86
87
88 dcon_write(dcon, 0x3a, 0xc040);
89 dcon_write(dcon, DCON_REG_MEM_OPT_A, 0x0000);
90 dcon_write(dcon, DCON_REG_MEM_OPT_A,
91 MEM_DLL_CLOCK_DELAY | MEM_POWER_DOWN);
92 dcon_write(dcon, DCON_REG_MEM_OPT_B, MEM_SOFT_RESET);
93
94
95 if (is_init) {
96 dcon->disp_mode = MODE_PASSTHRU | MODE_BL_ENABLE |
97 MODE_CSWIZZLE | MODE_COL_AA;
98 }
99 dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
100
101
102 dcon_write(dcon, DCON_REG_SCAN_INT, resumeline);
103
104err:
105 return rc;
106}
107
108
109
110
111
112
113
114
115
116
117static int dcon_bus_stabilize(struct dcon_priv *dcon, int is_powered_down)
118{
119 unsigned long timeout;
120 u8 pm;
121 int x;
122
123power_up:
124 if (is_powered_down) {
125 pm = 1;
126 x = olpc_ec_cmd(EC_DCON_POWER_MODE, &pm, 1, NULL, 0);
127 if (x) {
128 pr_warn("unable to force dcon to power up: %d!\n", x);
129 return x;
130 }
131 usleep_range(10000, 11000);
132 }
133
134 pdata->bus_stabilize_wiggle();
135
136 for (x = -1, timeout = 50; timeout && x < 0; timeout--) {
137 usleep_range(1000, 1100);
138 x = dcon_read(dcon, DCON_REG_ID);
139 }
140 if (x < 0) {
141 pr_err("unable to stabilize dcon's smbus, reasserting power and praying.\n");
142 BUG_ON(olpc_board_at_least(olpc_board(0xc2)));
143 pm = 0;
144 olpc_ec_cmd(EC_DCON_POWER_MODE, &pm, 1, NULL, 0);
145 msleep(100);
146 is_powered_down = 1;
147 goto power_up;
148 }
149
150 if (is_powered_down)
151 return dcon_hw_init(dcon, 0);
152 return 0;
153}
154
155static void dcon_set_backlight(struct dcon_priv *dcon, u8 level)
156{
157 dcon->bl_val = level;
158 dcon_write(dcon, DCON_REG_BRIGHT, dcon->bl_val);
159
160
161 if (dcon->bl_val == 0) {
162 dcon->disp_mode &= ~MODE_BL_ENABLE;
163 dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
164 } else if (!(dcon->disp_mode & MODE_BL_ENABLE)) {
165 dcon->disp_mode |= MODE_BL_ENABLE;
166 dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
167 }
168}
169
170
171static int dcon_set_mono_mode(struct dcon_priv *dcon, bool enable_mono)
172{
173 if (dcon->mono == enable_mono)
174 return 0;
175
176 dcon->mono = enable_mono;
177
178 if (enable_mono) {
179 dcon->disp_mode &= ~(MODE_CSWIZZLE | MODE_COL_AA);
180 dcon->disp_mode |= MODE_MONO_LUMA;
181 } else {
182 dcon->disp_mode &= ~(MODE_MONO_LUMA);
183 dcon->disp_mode |= MODE_CSWIZZLE | MODE_COL_AA;
184 }
185
186 dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode);
187 return 0;
188}
189
190
191
192
193
194static void dcon_sleep(struct dcon_priv *dcon, bool sleep)
195{
196 int x;
197
198
199
200 if (dcon->asleep == sleep)
201 return;
202
203 if (!olpc_board_at_least(olpc_board(0xc2)))
204 return;
205
206 if (sleep) {
207 u8 pm = 0;
208
209 x = olpc_ec_cmd(EC_DCON_POWER_MODE, &pm, 1, NULL, 0);
210 if (x)
211 pr_warn("unable to force dcon to power down: %d!\n", x);
212 else
213 dcon->asleep = sleep;
214 } else {
215
216 if (dcon->bl_val != 0)
217 dcon->disp_mode |= MODE_BL_ENABLE;
218 x = dcon_bus_stabilize(dcon, 1);
219 if (x)
220 pr_warn("unable to reinit dcon hardware: %d!\n", x);
221 else
222 dcon->asleep = sleep;
223
224
225 dcon_set_backlight(dcon, dcon->bl_val);
226 }
227
228
229}
230
231
232
233
234
235
236static void dcon_load_holdoff(struct dcon_priv *dcon)
237{
238 ktime_t delta_t, now;
239
240 while (1) {
241 now = ktime_get();
242 delta_t = ktime_sub(now, dcon->load_time);
243 if (ktime_to_ns(delta_t) > NSEC_PER_MSEC * 20)
244 break;
245 mdelay(4);
246 }
247}
248
249static bool dcon_blank_fb(struct dcon_priv *dcon, bool blank)
250{
251 int err;
252
253 console_lock();
254 lock_fb_info(dcon->fbinfo);
255
256 dcon->ignore_fb_events = true;
257 err = fb_blank(dcon->fbinfo,
258 blank ? FB_BLANK_POWERDOWN : FB_BLANK_UNBLANK);
259 dcon->ignore_fb_events = false;
260 unlock_fb_info(dcon->fbinfo);
261 console_unlock();
262
263 if (err) {
264 dev_err(&dcon->client->dev, "couldn't %sblank framebuffer\n",
265 blank ? "" : "un");
266 return false;
267 }
268 return true;
269}
270
271
272static void dcon_source_switch(struct work_struct *work)
273{
274 struct dcon_priv *dcon = container_of(work, struct dcon_priv,
275 switch_source);
276 int source = dcon->pending_src;
277
278 if (dcon->curr_src == source)
279 return;
280
281 dcon_load_holdoff(dcon);
282
283 dcon->switched = false;
284
285 switch (source) {
286 case DCON_SOURCE_CPU:
287 pr_info("%s to CPU\n", __func__);
288
289 if (dcon_write(dcon, DCON_REG_MODE,
290 dcon->disp_mode | MODE_SCAN_INT))
291 pr_err("couldn't enable scanline interrupt!\n");
292 else
293
294 wait_event_timeout(dcon->waitq, dcon->switched, HZ);
295
296 if (!dcon->switched)
297 pr_err("Timeout entering CPU mode; expect a screen glitch.\n");
298
299
300 if (dcon_write(dcon, DCON_REG_MODE, dcon->disp_mode))
301 pr_err("couldn't disable scanline interrupt!\n");
302
303
304
305
306
307
308
309
310
311 if (!dcon_blank_fb(dcon, false)) {
312 pr_err("Failed to enter CPU mode\n");
313 dcon->pending_src = DCON_SOURCE_DCON;
314 return;
315 }
316
317
318 pdata->set_dconload(1);
319 dcon->load_time = ktime_get();
320
321 pr_info("The CPU has control\n");
322 break;
323 case DCON_SOURCE_DCON:
324 {
325 ktime_t delta_t;
326
327 pr_info("%s to DCON\n", __func__);
328
329
330 pdata->set_dconload(0);
331 dcon->load_time = ktime_get();
332
333 wait_event_timeout(dcon->waitq, dcon->switched, HZ / 2);
334
335 if (!dcon->switched) {
336 pr_err("Timeout entering DCON mode; expect a screen glitch.\n");
337 } else {
338
339
340
341
342
343
344
345
346
347
348
349 delta_t = ktime_sub(dcon->irq_time, dcon->load_time);
350 if (dcon->switched && ktime_to_ns(delta_t)
351 < NSEC_PER_MSEC * 20) {
352 pr_err("missed loading, retrying\n");
353 pdata->set_dconload(1);
354 mdelay(41);
355 pdata->set_dconload(0);
356 dcon->load_time = ktime_get();
357 mdelay(41);
358 }
359 }
360
361 dcon_blank_fb(dcon, true);
362 pr_info("The DCON has control\n");
363 break;
364 }
365 default:
366 BUG();
367 }
368
369 dcon->curr_src = source;
370}
371
372static void dcon_set_source(struct dcon_priv *dcon, int arg)
373{
374 if (dcon->pending_src == arg)
375 return;
376
377 dcon->pending_src = arg;
378
379 if (dcon->curr_src != arg)
380 schedule_work(&dcon->switch_source);
381}
382
383static void dcon_set_source_sync(struct dcon_priv *dcon, int arg)
384{
385 dcon_set_source(dcon, arg);
386 flush_scheduled_work();
387}
388
389static ssize_t dcon_mode_show(struct device *dev,
390 struct device_attribute *attr,
391 char *buf)
392{
393 struct dcon_priv *dcon = dev_get_drvdata(dev);
394
395 return sprintf(buf, "%4.4X\n", dcon->disp_mode);
396}
397
398static ssize_t dcon_sleep_show(struct device *dev,
399 struct device_attribute *attr,
400 char *buf)
401{
402 struct dcon_priv *dcon = dev_get_drvdata(dev);
403
404 return sprintf(buf, "%d\n", dcon->asleep);
405}
406
407static ssize_t dcon_freeze_show(struct device *dev,
408 struct device_attribute *attr,
409 char *buf)
410{
411 struct dcon_priv *dcon = dev_get_drvdata(dev);
412
413 return sprintf(buf, "%d\n", dcon->curr_src == DCON_SOURCE_DCON ? 1 : 0);
414}
415
416static ssize_t dcon_mono_show(struct device *dev,
417 struct device_attribute *attr,
418 char *buf)
419{
420 struct dcon_priv *dcon = dev_get_drvdata(dev);
421
422 return sprintf(buf, "%d\n", dcon->mono);
423}
424
425static ssize_t dcon_resumeline_show(struct device *dev,
426 struct device_attribute *attr,
427 char *buf)
428{
429 return sprintf(buf, "%d\n", resumeline);
430}
431
432static ssize_t dcon_mono_store(struct device *dev,
433 struct device_attribute *attr,
434 const char *buf, size_t count)
435{
436 unsigned long enable_mono;
437 int rc;
438
439 rc = kstrtoul(buf, 10, &enable_mono);
440 if (rc)
441 return rc;
442
443 dcon_set_mono_mode(dev_get_drvdata(dev), enable_mono ? true : false);
444
445 return count;
446}
447
448static ssize_t dcon_freeze_store(struct device *dev,
449 struct device_attribute *attr,
450 const char *buf, size_t count)
451{
452 struct dcon_priv *dcon = dev_get_drvdata(dev);
453 unsigned long output;
454 int ret;
455
456 ret = kstrtoul(buf, 10, &output);
457 if (ret)
458 return ret;
459
460 switch (output) {
461 case 0:
462 dcon_set_source(dcon, DCON_SOURCE_CPU);
463 break;
464 case 1:
465 dcon_set_source_sync(dcon, DCON_SOURCE_DCON);
466 break;
467 case 2:
468 dcon_set_source(dcon, DCON_SOURCE_DCON);
469 break;
470 default:
471 return -EINVAL;
472 }
473
474 return count;
475}
476
477static ssize_t dcon_resumeline_store(struct device *dev,
478 struct device_attribute *attr,
479 const char *buf, size_t count)
480{
481 unsigned short rl;
482 int rc;
483
484 rc = kstrtou16(buf, 10, &rl);
485 if (rc)
486 return rc;
487
488 resumeline = rl;
489 dcon_write(dev_get_drvdata(dev), DCON_REG_SCAN_INT, resumeline);
490
491 return count;
492}
493
494static ssize_t dcon_sleep_store(struct device *dev,
495 struct device_attribute *attr,
496 const char *buf, size_t count)
497{
498 unsigned long output;
499 int ret;
500
501 ret = kstrtoul(buf, 10, &output);
502 if (ret)
503 return ret;
504
505 dcon_sleep(dev_get_drvdata(dev), output ? true : false);
506 return count;
507}
508
509static struct device_attribute dcon_device_files[] = {
510 __ATTR(mode, 0444, dcon_mode_show, NULL),
511 __ATTR(sleep, 0644, dcon_sleep_show, dcon_sleep_store),
512 __ATTR(freeze, 0644, dcon_freeze_show, dcon_freeze_store),
513 __ATTR(monochrome, 0644, dcon_mono_show, dcon_mono_store),
514 __ATTR(resumeline, 0644, dcon_resumeline_show, dcon_resumeline_store),
515};
516
517static int dcon_bl_update(struct backlight_device *dev)
518{
519 struct dcon_priv *dcon = bl_get_data(dev);
520 u8 level = dev->props.brightness & 0x0F;
521
522 if (dev->props.power != FB_BLANK_UNBLANK)
523 level = 0;
524
525 if (level != dcon->bl_val)
526 dcon_set_backlight(dcon, level);
527
528
529 if (!dcon->ignore_fb_events)
530 dcon_sleep(dcon, !!(dev->props.state & BL_CORE_FBBLANK));
531
532 return 0;
533}
534
535static int dcon_bl_get(struct backlight_device *dev)
536{
537 struct dcon_priv *dcon = bl_get_data(dev);
538
539 return dcon->bl_val;
540}
541
542static const struct backlight_ops dcon_bl_ops = {
543 .update_status = dcon_bl_update,
544 .get_brightness = dcon_bl_get,
545};
546
547static struct backlight_properties dcon_bl_props = {
548 .max_brightness = 15,
549 .type = BACKLIGHT_RAW,
550 .power = FB_BLANK_UNBLANK,
551};
552
553static int dcon_reboot_notify(struct notifier_block *nb,
554 unsigned long foo, void *bar)
555{
556 struct dcon_priv *dcon = container_of(nb, struct dcon_priv, reboot_nb);
557
558 if (!dcon || !dcon->client)
559 return NOTIFY_DONE;
560
561
562 dcon_write(dcon, DCON_REG_MODE, 0x39);
563 dcon_write(dcon, DCON_REG_MODE, 0x32);
564 return NOTIFY_DONE;
565}
566
567static int unfreeze_on_panic(struct notifier_block *nb,
568 unsigned long e, void *p)
569{
570 pdata->set_dconload(1);
571 return NOTIFY_DONE;
572}
573
574static struct notifier_block dcon_panic_nb = {
575 .notifier_call = unfreeze_on_panic,
576};
577
578static int dcon_detect(struct i2c_client *client, struct i2c_board_info *info)
579{
580 strscpy(info->type, "olpc_dcon", I2C_NAME_SIZE);
581
582 return 0;
583}
584
585static int dcon_probe(struct i2c_client *client, const struct i2c_device_id *id)
586{
587 struct dcon_priv *dcon;
588 int rc, i, j;
589
590 if (!pdata)
591 return -ENXIO;
592
593 dcon = kzalloc(sizeof(*dcon), GFP_KERNEL);
594 if (!dcon)
595 return -ENOMEM;
596
597 dcon->client = client;
598 init_waitqueue_head(&dcon->waitq);
599 INIT_WORK(&dcon->switch_source, dcon_source_switch);
600 dcon->reboot_nb.notifier_call = dcon_reboot_notify;
601 dcon->reboot_nb.priority = -1;
602
603 i2c_set_clientdata(client, dcon);
604
605 if (num_registered_fb < 1) {
606 dev_err(&client->dev, "DCON driver requires a registered fb\n");
607 rc = -EIO;
608 goto einit;
609 }
610 dcon->fbinfo = registered_fb[0];
611
612 rc = dcon_hw_init(dcon, 1);
613 if (rc)
614 goto einit;
615
616
617
618 dcon_device = platform_device_alloc("dcon", -1);
619
620 if (!dcon_device) {
621 pr_err("Unable to create the DCON device\n");
622 rc = -ENOMEM;
623 goto eirq;
624 }
625 rc = platform_device_add(dcon_device);
626 platform_set_drvdata(dcon_device, dcon);
627
628 if (rc) {
629 pr_err("Unable to add the DCON device\n");
630 goto edev;
631 }
632
633 for (i = 0; i < ARRAY_SIZE(dcon_device_files); i++) {
634 rc = device_create_file(&dcon_device->dev,
635 &dcon_device_files[i]);
636 if (rc) {
637 dev_err(&dcon_device->dev, "Cannot create sysfs file\n");
638 goto ecreate;
639 }
640 }
641
642 dcon->bl_val = dcon_read(dcon, DCON_REG_BRIGHT) & 0x0F;
643
644
645 dcon_bl_props.brightness = dcon->bl_val;
646 dcon->bl_dev = backlight_device_register("dcon-bl", &dcon_device->dev,
647 dcon, &dcon_bl_ops,
648 &dcon_bl_props);
649 if (IS_ERR(dcon->bl_dev)) {
650 dev_err(&client->dev, "cannot register backlight dev (%ld)\n",
651 PTR_ERR(dcon->bl_dev));
652 dcon->bl_dev = NULL;
653 }
654
655 register_reboot_notifier(&dcon->reboot_nb);
656 atomic_notifier_chain_register(&panic_notifier_list, &dcon_panic_nb);
657
658 return 0;
659
660 ecreate:
661 for (j = 0; j < i; j++)
662 device_remove_file(&dcon_device->dev, &dcon_device_files[j]);
663 platform_device_del(dcon_device);
664 edev:
665 platform_device_put(dcon_device);
666 dcon_device = NULL;
667 eirq:
668 free_irq(DCON_IRQ, dcon);
669 einit:
670 kfree(dcon);
671 return rc;
672}
673
674static int dcon_remove(struct i2c_client *client)
675{
676 struct dcon_priv *dcon = i2c_get_clientdata(client);
677
678 unregister_reboot_notifier(&dcon->reboot_nb);
679 atomic_notifier_chain_unregister(&panic_notifier_list, &dcon_panic_nb);
680
681 free_irq(DCON_IRQ, dcon);
682
683 backlight_device_unregister(dcon->bl_dev);
684
685 if (dcon_device)
686 platform_device_unregister(dcon_device);
687 cancel_work_sync(&dcon->switch_source);
688
689 kfree(dcon);
690
691 return 0;
692}
693
694#ifdef CONFIG_PM
695static int dcon_suspend(struct device *dev)
696{
697 struct i2c_client *client = to_i2c_client(dev);
698 struct dcon_priv *dcon = i2c_get_clientdata(client);
699
700 if (!dcon->asleep) {
701
702 dcon_set_source_sync(dcon, DCON_SOURCE_DCON);
703 }
704
705 return 0;
706}
707
708static int dcon_resume(struct device *dev)
709{
710 struct i2c_client *client = to_i2c_client(dev);
711 struct dcon_priv *dcon = i2c_get_clientdata(client);
712
713 if (!dcon->asleep) {
714 dcon_bus_stabilize(dcon, 0);
715 dcon_set_source(dcon, DCON_SOURCE_CPU);
716 }
717
718 return 0;
719}
720
721#else
722
723#define dcon_suspend NULL
724#define dcon_resume NULL
725
726#endif
727
728irqreturn_t dcon_interrupt(int irq, void *id)
729{
730 struct dcon_priv *dcon = id;
731 u8 status;
732
733 if (pdata->read_status(&status))
734 return IRQ_NONE;
735
736 switch (status & 3) {
737 case 3:
738 pr_debug("DCONLOAD_MISSED interrupt\n");
739 break;
740
741 case 2:
742 case 1:
743 dcon->switched = true;
744 dcon->irq_time = ktime_get();
745 wake_up(&dcon->waitq);
746 break;
747
748 case 0:
749
750
751
752
753
754
755
756 if (dcon->curr_src != dcon->pending_src && !dcon->switched) {
757 dcon->switched = true;
758 dcon->irq_time = ktime_get();
759 wake_up(&dcon->waitq);
760 pr_debug("switching w/ status 0/0\n");
761 } else {
762 pr_debug("scanline interrupt w/CPU\n");
763 }
764 }
765
766 return IRQ_HANDLED;
767}
768
769static const struct dev_pm_ops dcon_pm_ops = {
770 .suspend = dcon_suspend,
771 .resume = dcon_resume,
772};
773
774static const struct i2c_device_id dcon_idtable[] = {
775 { "olpc_dcon", 0 },
776 { }
777};
778MODULE_DEVICE_TABLE(i2c, dcon_idtable);
779
780static struct i2c_driver dcon_driver = {
781 .driver = {
782 .name = "olpc_dcon",
783 .pm = &dcon_pm_ops,
784 },
785 .class = I2C_CLASS_DDC | I2C_CLASS_HWMON,
786 .id_table = dcon_idtable,
787 .probe = dcon_probe,
788 .remove = dcon_remove,
789 .detect = dcon_detect,
790 .address_list = normal_i2c,
791};
792
793static int __init olpc_dcon_init(void)
794{
795
796 if (olpc_board_at_least(olpc_board(0xd0)))
797 pdata = &dcon_pdata_xo_1_5;
798 else
799 pdata = &dcon_pdata_xo_1;
800
801 return i2c_add_driver(&dcon_driver);
802}
803
804static void __exit olpc_dcon_exit(void)
805{
806 i2c_del_driver(&dcon_driver);
807}
808
809module_init(olpc_dcon_init);
810module_exit(olpc_dcon_exit);
811
812MODULE_LICENSE("GPL");
813