summaryrefslogtreecommitdiffstats
path: root/arch/x86/platform/olpc/olpc-xo1-sci.c
blob: 74704be7b1fe85a4400cc4404a5748f070e39b0a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
/*
 * Support for OLPC XO-1 System Control Interrupts (SCI)
 *
 * Copyright (C) 2010 One Laptop per Child
 * Copyright (C) 2006 Red Hat, Inc.
 * Copyright (C) 2006 Advanced Micro Devices, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/cs5535.h>
#include <linux/device.h>
#include <linux/gpio.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/pm_wakeup.h>
#include <linux/mfd/core.h>
#include <linux/power_supply.h>
#include <linux/suspend.h>
#include <linux/workqueue.h>
#include <linux/olpc-ec.h>

#include <asm/io.h>
#include <asm/msr.h>
#include <asm/olpc.h>

#define DRV_NAME	"olpc-xo1-sci"
#define PFX		DRV_NAME ": "

static unsigned long acpi_base;
static struct input_dev *power_button_idev;
static struct input_dev *ebook_switch_idev;
static struct input_dev *lid_switch_idev;

static int sci_irq;

static bool lid_open;
static bool lid_inverted;
static int lid_wake_mode;

enum lid_wake_modes {
	LID_WAKE_ALWAYS,
	LID_WAKE_OPEN,
	LID_WAKE_CLOSE,
};

static const char * const lid_wake_mode_names[] = {
	[LID_WAKE_ALWAYS] = "always",
	[LID_WAKE_OPEN] = "open",
	[LID_WAKE_CLOSE] = "close",
};

static void battery_status_changed(void)
{
	struct power_supply *psy = power_supply_get_by_name("olpc-battery");

	if (psy) {
		power_supply_changed(psy);
		put_device(psy->dev);
	}
}

static void ac_status_changed(void)
{
	struct power_supply *psy = power_supply_get_by_name("olpc-ac");

	if (psy) {
		power_supply_changed(psy);
		put_device(psy->dev);
	}
}

/* Report current ebook switch state through input layer */
static void send_ebook_state(void)
{
	unsigned char state;

	if (olpc_ec_cmd(EC_READ_EB_MODE, NULL, 0, &state, 1)) {
		pr_err(PFX "failed to get ebook state\n");
		return;
	}

	if (!!test_bit(SW_TABLET_MODE, ebook_switch_idev->sw) == state)
		return; /* Nothing new to report. */

	input_report_switch(ebook_switch_idev, SW_TABLET_MODE, state);
	input_sync(ebook_switch_idev);
	pm_wakeup_event(&ebook_switch_idev->dev, 0);
}

static void flip_lid_inverter(void)
{
	/* gpio is high; invert so we'll get l->h event interrupt */
	if (lid_inverted)
		cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
	else
		cs5535_gpio_set(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
	lid_inverted = !lid_inverted;
}

static void detect_lid_state(void)
{
	/*
	 * the edge detector hookup on the gpio inputs on the geode is
	 * odd, to say the least.  See http://dev.laptop.org/ticket/5703
	 * for details, but in a nutshell:  we don't use the edge
	 * detectors.  instead, we make use of an anomoly:  with the both
	 * edge detectors turned off, we still get an edge event on a
	 * positive edge transition.  to take advantage of this, we use the
	 * front-end inverter to ensure that that's the edge we're always
	 * going to see next.
	 */

	int state;

	state = cs5535_gpio_isset(OLPC_GPIO_LID, GPIO_READ_BACK);
	lid_open = !state ^ !lid_inverted; /* x ^^ y */
	if (!state)
		return;

	flip_lid_inverter();
}

/* Report current lid switch state through input layer */
static void send_lid_state(void)
{
	if (!!test_bit(SW_LID, lid_switch_idev->sw) == !lid_open)
		return; /* Nothing new to report. */

	input_report_switch(lid_switch_idev, SW_LID, !lid_open);
	input_sync(lid_switch_idev);
	pm_wakeup_event(&lid_switch_idev->dev, 0);
}

static ssize_t lid_wake_mode_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
{
	const char *mode = lid_wake_mode_names[lid_wake_mode];
	return sprintf(buf, "%s\n", mode);
}
static ssize_t lid_wake_mode_set(struct device *dev,
				 struct device_attribute *attr,
				 const char *buf, size_t count)
{
	int i;
	for (i = 0; i < ARRAY_SIZE(lid_wake_mode_names); i++) {
		const char *mode = lid_wake_mode_names[i];
		if (strlen(mode) != count || strncasecmp(mode, buf, count))
			continue;

		lid_wake_mode = i;
		return count;
	}
	return -EINVAL;
}
static DEVICE_ATTR(lid_wake_mode, S_IWUSR | S_IRUGO, lid_wake_mode_show,
		   lid_wake_mode_set);

/*
 * Process all items in the EC's SCI queue.
 *
 * This is handled in a workqueue because olpc_ec_cmd can be slow (and
 * can even timeout).
 *
 * If propagate_events is false, the queue is drained without events being
 * generated for the interrupts.
 */
static void process_sci_queue(bool propagate_events)
{
	int r;
	u16 data;

	do {
		r = olpc_ec_sci_query(&data);
		if (r || !data)
			break;

		pr_debug(PFX "SCI 0x%x received\n", data);

		switch (data) {
		case EC_SCI_SRC_BATERR:
		case EC_SCI_SRC_BATSOC:
		case EC_SCI_SRC_BATTERY:
		case EC_SCI_SRC_BATCRIT:
			battery_status_changed();
			break;
		case EC_SCI_SRC_ACPWR:
			ac_status_changed();
			break;
		}

		if (data == EC_SCI_SRC_EBOOK && propagate_events)
			send_ebook_state();
	} while (data);

	if (r)
		pr_err(PFX "Failed to clear SCI queue");
}

static void process_sci_queue_work(struct work_struct *work)
{
	process_sci_queue(true);
}

static DECLARE_WORK(sci_work, process_sci_queue_work);

static irqreturn_t xo1_sci_intr(int irq, void *dev_id)
{
	struct platform_device *pdev = dev_id;
	u32 sts;
	u32 gpe;

	sts = inl(acpi_base + CS5536_PM1_STS);
	outl(sts | 0xffff, acpi_base + CS5536_PM1_STS);

	gpe = inl(acpi_base + CS5536_PM_GPE0_STS);
	outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);

	dev_dbg(&pdev->dev, "sts %x gpe %x\n", sts, gpe);

	if (sts & CS5536_PWRBTN_FLAG) {
		if (!(sts & CS5536_WAK_FLAG)) {
			/* Only report power button input when it was pressed
			 * during regular operation (as opposed to when it
			 * was used to wake the system). */
			input_report_key(power_button_idev, KEY_POWER, 1);
			input_sync(power_button_idev);
			input_report_key(power_button_idev, KEY_POWER, 0);
			input_sync(power_button_idev);
		}
		/* Report the wakeup event in all cases. */
		pm_wakeup_event(&power_button_idev->dev, 0);
	}

	if ((sts & (CS5536_RTC_FLAG | CS5536_WAK_FLAG)) ==
			(CS5536_RTC_FLAG | CS5536_WAK_FLAG)) {
		/* When the system is woken by the RTC alarm, report the
		 * event on the rtc device. */
		struct device *rtc = bus_find_device_by_name(
			&platform_bus_type, NULL, "rtc_cmos");
		if (rtc) {
			pm_wakeup_event(rtc, 0);
			put_device(rtc);
		}
	}

	if (gpe & CS5536_GPIOM7_PME_FLAG) { /* EC GPIO */
		cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_NEGATIVE_EDGE_STS);
		schedule_work(&sci_work);
	}

	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
	detect_lid_state();
	send_lid_state();

	return IRQ_HANDLED;
}

static int xo1_sci_suspend(struct platform_device *pdev, pm_message_t state)
{
	if (device_may_wakeup(&power_button_idev->dev))
		olpc_xo1_pm_wakeup_set(CS5536_PM_PWRBTN);
	else
		olpc_xo1_pm_wakeup_clear(CS5536_PM_PWRBTN);

	if (device_may_wakeup(&ebook_switch_idev->dev))
		olpc_ec_wakeup_set(EC_SCI_SRC_EBOOK);
	else
		olpc_ec_wakeup_clear(EC_SCI_SRC_EBOOK);

	if (!device_may_wakeup(&lid_switch_idev->dev)) {
		cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
	} else if ((lid_open && lid_wake_mode == LID_WAKE_OPEN) ||
		   (!lid_open && lid_wake_mode == LID_WAKE_CLOSE)) {
		flip_lid_inverter();

		/* we may have just caused an event */
		cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
		cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);

		cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
	}

	return 0;
}

static int xo1_sci_resume(struct platform_device *pdev)
{
	/*
	 * We don't know what may have happened while we were asleep.
	 * Reestablish our lid setup so we're sure to catch all transitions.
	 */
	detect_lid_state();
	send_lid_state();
	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);

	/* Enable all EC events */
	olpc_ec_mask_write(EC_SCI_SRC_ALL);

	/* Power/battery status might have changed too */
	battery_status_changed();
	ac_status_changed();
	return 0;
}

static int setup_sci_interrupt(struct platform_device *pdev)
{
	u32 lo, hi;
	u32 sts;
	int r;

	rdmsr(0x51400020, lo, hi);
	sci_irq = (lo >> 20) & 15;

	if (sci_irq) {
		dev_info(&pdev->dev, "SCI is mapped to IRQ %d\n", sci_irq);
	} else {
		/* Zero means masked */
		dev_info(&pdev->dev, "SCI unmapped. Mapping to IRQ 3\n");
		sci_irq = 3;
		lo |= 0x00300000;
		wrmsrl(0x51400020, lo);
	}

	/* Select level triggered in PIC */
	if (sci_irq < 8) {
		lo = inb(CS5536_PIC_INT_SEL1);
		lo |= 1 << sci_irq;
		outb(lo, CS5536_PIC_INT_SEL1);
	} else {
		lo = inb(CS5536_PIC_INT_SEL2);
		lo |= 1 << (sci_irq - 8);
		outb(lo, CS5536_PIC_INT_SEL2);
	}

	/* Enable interesting SCI events, and clear pending interrupts */
	sts = inl(acpi_base + CS5536_PM1_STS);
	outl(((CS5536_PM_PWRBTN | CS5536_PM_RTC) << 16) | 0xffff,
	     acpi_base + CS5536_PM1_STS);

	r = request_irq(sci_irq, xo1_sci_intr, 0, DRV_NAME, pdev);
	if (r)
		dev_err(&pdev->dev, "can't request interrupt\n");

	return r;
}

static int setup_ec_sci(void)
{
	int r;

	r = gpio_request(OLPC_GPIO_ECSCI, "OLPC-ECSCI");
	if (r)
		return r;

	gpio_direction_input(OLPC_GPIO_ECSCI);

	/* Clear pending EC SCI events */
	cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_NEGATIVE_EDGE_STS);
	cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_POSITIVE_EDGE_STS);

	/*
	 * Enable EC SCI events, and map them to both a PME and the SCI
	 * interrupt.
	 *
	 * Ordinarily, in addition to functioning as GPIOs, Geode GPIOs can
	 * be mapped to regular interrupts *or* Geode-specific Power
	 * Management Events (PMEs) - events that bring the system out of
	 * suspend. In this case, we want both of those things - the system
	 * wakeup, *and* the ability to get an interrupt when an event occurs.
	 *
	 * To achieve this, we map the GPIO to a PME, and then we use one
	 * of the many generic knobs on the CS5535 PIC to additionally map the
	 * PME to the regular SCI interrupt line.
	 */
	cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_EVENTS_ENABLE);

	/* Set the SCI to cause a PME event on group 7 */
	cs5535_gpio_setup_event(OLPC_GPIO_ECSCI, 7, 1);

	/* And have group 7 also fire the SCI interrupt */
	cs5535_pic_unreqz_select_high(7, sci_irq);

	return 0;
}

static void free_ec_sci(void)
{
	gpio_free(OLPC_GPIO_ECSCI);
}

static int setup_lid_events(void)
{
	int r;

	r = gpio_request(OLPC_GPIO_LID, "OLPC-LID");
	if (r)
		return r;

	gpio_direction_input(OLPC_GPIO_LID);

	cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
	lid_inverted = 0;

	/* Clear edge detection and event enable for now */
	cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
	cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_EN);
	cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_EN);
	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);

	/* Set the LID to cause an PME event on group 6 */
	cs5535_gpio_setup_event(OLPC_GPIO_LID, 6, 1);

	/* Set PME group 6 to fire the SCI interrupt */
	cs5535_gpio_set_irq(6, sci_irq);

	/* Enable the event */
	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);

	return 0;
}

static void free_lid_events(void)
{
	gpio_free(OLPC_GPIO_LID);
}

static int setup_power_button(struct platform_device *pdev)
{
	int r;

	power_button_idev = input_allocate_device();
	if (!power_button_idev)
		return -ENOMEM;

	power_button_idev->name = "Power Button";
	power_button_idev->phys = DRV_NAME "/input0";
	set_bit(EV_KEY, power_button_idev->evbit);
	set_bit(KEY_POWER, power_button_idev->keybit);

	power_button_idev->dev.parent = &pdev->dev;
	device_init_wakeup(&power_button_idev->dev, 1);

	r = input_register_device(power_button_idev);
	if (r) {
		dev_err(&pdev->dev, "failed to register power button: %d\n", r);
		input_free_device(power_button_idev);
	}

	return r;
}

static void free_power_button(void)
{
	input_unregister_device(power_button_idev);
	input_free_device(power_button_idev);
}

static int setup_ebook_switch(struct platform_device *pdev)
{
	int r;

	ebook_switch_idev = input_allocate_device();
	if (!ebook_switch_idev)
		return -ENOMEM;

	ebook_switch_idev->name = "EBook Switch";
	ebook_switch_idev->phys = DRV_NAME "/input1";
	set_bit(EV_SW, ebook_switch_idev->evbit);
	set_bit(SW_TABLET_MODE, ebook_switch_idev->swbit);

	ebook_switch_idev->dev.parent = &pdev->dev;
	device_set_wakeup_capable(&ebook_switch_idev->dev, true);

	r = input_register_device(ebook_switch_idev);
	if (r) {
		dev_err(&pdev->dev, "failed to register ebook switch: %d\n", r);
		input_free_device(ebook_switch_idev);
	}

	return r;
}

static void free_ebook_switch(void)
{
	input_unregister_device(ebook_switch_idev);
	input_free_device(ebook_switch_idev);
}

static int setup_lid_switch(struct platform_device *pdev)
{
	int r;

	lid_switch_idev = input_allocate_device();
	if (!lid_switch_idev)
		return -ENOMEM;

	lid_switch_idev->name = "Lid Switch";
	lid_switch_idev->phys = DRV_NAME "/input2";
	set_bit(EV_SW, lid_switch_idev->evbit);
	set_bit(SW_LID, lid_switch_idev->swbit);

	lid_switch_idev->dev.parent = &pdev->dev;
	device_set_wakeup_capable(&lid_switch_idev->dev, true);

	r = input_register_device(lid_switch_idev);
	if (r) {
		dev_err(&pdev->dev, "failed to register lid switch: %d\n", r);
		goto err_register;
	}

	r = device_create_file(&lid_switch_idev->dev, &dev_attr_lid_wake_mode);
	if (r) {
		dev_err(&pdev->dev, "failed to create wake mode attr: %d\n", r);
		goto err_create_attr;
	}

	return 0;

err_create_attr:
	input_unregister_device(lid_switch_idev);
err_register:
	input_free_device(lid_switch_idev);
	return r;
}

static void free_lid_switch(void)
{
	device_remove_file(&lid_switch_idev->dev, &dev_attr_lid_wake_mode);
	input_unregister_device(lid_switch_idev);
	input_free_device(lid_switch_idev);
}

static int xo1_sci_probe(struct platform_device *pdev)
{
	struct resource *res;
	int r;

	/* don't run on non-XOs */
	if (!machine_is_olpc())
		return -ENODEV;

	r = mfd_cell_enable(pdev);
	if (r)
		return r;

	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
	if (!res) {
		dev_err(&pdev->dev, "can't fetch device resource info\n");
		return -EIO;
	}
	acpi_base = res->start;

	r = setup_power_button(pdev);
	if (r)
		return r;

	r = setup_ebook_switch(pdev);
	if (r)
		goto err_ebook;

	r = setup_lid_switch(pdev);
	if (r)
		goto err_lid;

	r = setup_lid_events();
	if (r)
		goto err_lidevt;

	r = setup_ec_sci();
	if (r)
		goto err_ecsci;

	/* Enable PME generation for EC-generated events */
	outl(CS5536_GPIOM6_PME_EN | CS5536_GPIOM7_PME_EN,
		acpi_base + CS5536_PM_GPE0_EN);

	/* Clear pending events */
	outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
	process_sci_queue(false);

	/* Initial sync */
	send_ebook_state();
	detect_lid_state();
	send_lid_state();

	r = setup_sci_interrupt(pdev);
	if (r)
		goto err_sci;

	/* Enable all EC events */
	olpc_ec_mask_write(EC_SCI_SRC_ALL);

	return r;

err_sci:
	free_ec_sci();
err_ecsci:
	free_lid_events();
err_lidevt:
	free_lid_switch();
err_lid:
	free_ebook_switch();
err_ebook:
	free_power_button();
	return r;
}

static int xo1_sci_remove(struct platform_device *pdev)
{
	mfd_cell_disable(pdev);
	free_irq(sci_irq, pdev);
	cancel_work_sync(&sci_work);
	free_ec_sci();
	free_lid_events();
	free_lid_switch();
	free_ebook_switch();
	free_power_button();
	acpi_base = 0;
	return 0;
}

static struct platform_driver xo1_sci_driver = {
	.driver = {
		.name = "olpc-xo1-sci-acpi",
	},
	.probe = xo1_sci_probe,
	.remove = xo1_sci_remove,
	.suspend = xo1_sci_suspend,
	.resume = xo1_sci_resume,
};

static int __init xo1_sci_init(void)
{
	return platform_driver_register(&xo1_sci_driver);
}
arch_initcall(xo1_sci_init);