1/*
2 * Support for OLPC XO-1 System Control Interrupts (SCI)
3 *
4 * Copyright (C) 2010 One Laptop per Child
5 * Copyright (C) 2006 Red Hat, Inc.
6 * Copyright (C) 2006 Advanced Micro Devices, Inc.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 */
13
14#include <linux/cs5535.h>
15#include <linux/device.h>
16#include <linux/gpio.h>
17#include <linux/input.h>
18#include <linux/interrupt.h>
19#include <linux/platform_device.h>
20#include <linux/pm.h>
21#include <linux/pm_wakeup.h>
22#include <linux/mfd/core.h>
23#include <linux/power_supply.h>
24#include <linux/suspend.h>
25#include <linux/workqueue.h>
26#include <linux/olpc-ec.h>
27
28#include <asm/io.h>
29#include <asm/msr.h>
30#include <asm/olpc.h>
31
32#define DRV_NAME	"olpc-xo1-sci"
33#define PFX		DRV_NAME ": "
34
35static unsigned long acpi_base;
36static struct input_dev *power_button_idev;
37static struct input_dev *ebook_switch_idev;
38static struct input_dev *lid_switch_idev;
39
40static int sci_irq;
41
42static bool lid_open;
43static bool lid_inverted;
44static int lid_wake_mode;
45
46enum lid_wake_modes {
47	LID_WAKE_ALWAYS,
48	LID_WAKE_OPEN,
49	LID_WAKE_CLOSE,
50};
51
52static const char * const lid_wake_mode_names[] = {
53	[LID_WAKE_ALWAYS] = "always",
54	[LID_WAKE_OPEN] = "open",
55	[LID_WAKE_CLOSE] = "close",
56};
57
58static void battery_status_changed(void)
59{
60	struct power_supply *psy = power_supply_get_by_name("olpc-battery");
61
62	if (psy) {
63		power_supply_changed(psy);
64		power_supply_put(psy);
65	}
66}
67
68static void ac_status_changed(void)
69{
70	struct power_supply *psy = power_supply_get_by_name("olpc-ac");
71
72	if (psy) {
73		power_supply_changed(psy);
74		power_supply_put(psy);
75	}
76}
77
78/* Report current ebook switch state through input layer */
79static void send_ebook_state(void)
80{
81	unsigned char state;
82
83	if (olpc_ec_cmd(EC_READ_EB_MODE, NULL, 0, &state, 1)) {
84		pr_err(PFX "failed to get ebook state\n");
85		return;
86	}
87
88	if (!!test_bit(SW_TABLET_MODE, ebook_switch_idev->sw) == state)
89		return; /* Nothing new to report. */
90
91	input_report_switch(ebook_switch_idev, SW_TABLET_MODE, state);
92	input_sync(ebook_switch_idev);
93	pm_wakeup_event(&ebook_switch_idev->dev, 0);
94}
95
96static void flip_lid_inverter(void)
97{
98	/* gpio is high; invert so we'll get l->h event interrupt */
99	if (lid_inverted)
100		cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
101	else
102		cs5535_gpio_set(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
103	lid_inverted = !lid_inverted;
104}
105
106static void detect_lid_state(void)
107{
108	/*
109	 * the edge detector hookup on the gpio inputs on the geode is
110	 * odd, to say the least.  See http://dev.laptop.org/ticket/5703
111	 * for details, but in a nutshell:  we don't use the edge
112	 * detectors.  instead, we make use of an anomoly:  with the both
113	 * edge detectors turned off, we still get an edge event on a
114	 * positive edge transition.  to take advantage of this, we use the
115	 * front-end inverter to ensure that that's the edge we're always
116	 * going to see next.
117	 */
118
119	int state;
120
121	state = cs5535_gpio_isset(OLPC_GPIO_LID, GPIO_READ_BACK);
122	lid_open = !state ^ !lid_inverted; /* x ^^ y */
123	if (!state)
124		return;
125
126	flip_lid_inverter();
127}
128
129/* Report current lid switch state through input layer */
130static void send_lid_state(void)
131{
132	if (!!test_bit(SW_LID, lid_switch_idev->sw) == !lid_open)
133		return; /* Nothing new to report. */
134
135	input_report_switch(lid_switch_idev, SW_LID, !lid_open);
136	input_sync(lid_switch_idev);
137	pm_wakeup_event(&lid_switch_idev->dev, 0);
138}
139
140static ssize_t lid_wake_mode_show(struct device *dev,
141				  struct device_attribute *attr, char *buf)
142{
143	const char *mode = lid_wake_mode_names[lid_wake_mode];
144	return sprintf(buf, "%s\n", mode);
145}
146static ssize_t lid_wake_mode_set(struct device *dev,
147				 struct device_attribute *attr,
148				 const char *buf, size_t count)
149{
150	int i;
151	for (i = 0; i < ARRAY_SIZE(lid_wake_mode_names); i++) {
152		const char *mode = lid_wake_mode_names[i];
153		if (strlen(mode) != count || strncasecmp(mode, buf, count))
154			continue;
155
156		lid_wake_mode = i;
157		return count;
158	}
159	return -EINVAL;
160}
161static DEVICE_ATTR(lid_wake_mode, S_IWUSR | S_IRUGO, lid_wake_mode_show,
162		   lid_wake_mode_set);
163
164/*
165 * Process all items in the EC's SCI queue.
166 *
167 * This is handled in a workqueue because olpc_ec_cmd can be slow (and
168 * can even timeout).
169 *
170 * If propagate_events is false, the queue is drained without events being
171 * generated for the interrupts.
172 */
173static void process_sci_queue(bool propagate_events)
174{
175	int r;
176	u16 data;
177
178	do {
179		r = olpc_ec_sci_query(&data);
180		if (r || !data)
181			break;
182
183		pr_debug(PFX "SCI 0x%x received\n", data);
184
185		switch (data) {
186		case EC_SCI_SRC_BATERR:
187		case EC_SCI_SRC_BATSOC:
188		case EC_SCI_SRC_BATTERY:
189		case EC_SCI_SRC_BATCRIT:
190			battery_status_changed();
191			break;
192		case EC_SCI_SRC_ACPWR:
193			ac_status_changed();
194			break;
195		}
196
197		if (data == EC_SCI_SRC_EBOOK && propagate_events)
198			send_ebook_state();
199	} while (data);
200
201	if (r)
202		pr_err(PFX "Failed to clear SCI queue");
203}
204
205static void process_sci_queue_work(struct work_struct *work)
206{
207	process_sci_queue(true);
208}
209
210static DECLARE_WORK(sci_work, process_sci_queue_work);
211
212static irqreturn_t xo1_sci_intr(int irq, void *dev_id)
213{
214	struct platform_device *pdev = dev_id;
215	u32 sts;
216	u32 gpe;
217
218	sts = inl(acpi_base + CS5536_PM1_STS);
219	outl(sts | 0xffff, acpi_base + CS5536_PM1_STS);
220
221	gpe = inl(acpi_base + CS5536_PM_GPE0_STS);
222	outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
223
224	dev_dbg(&pdev->dev, "sts %x gpe %x\n", sts, gpe);
225
226	if (sts & CS5536_PWRBTN_FLAG) {
227		if (!(sts & CS5536_WAK_FLAG)) {
228			/* Only report power button input when it was pressed
229			 * during regular operation (as opposed to when it
230			 * was used to wake the system). */
231			input_report_key(power_button_idev, KEY_POWER, 1);
232			input_sync(power_button_idev);
233			input_report_key(power_button_idev, KEY_POWER, 0);
234			input_sync(power_button_idev);
235		}
236		/* Report the wakeup event in all cases. */
237		pm_wakeup_event(&power_button_idev->dev, 0);
238	}
239
240	if ((sts & (CS5536_RTC_FLAG | CS5536_WAK_FLAG)) ==
241			(CS5536_RTC_FLAG | CS5536_WAK_FLAG)) {
242		/* When the system is woken by the RTC alarm, report the
243		 * event on the rtc device. */
244		struct device *rtc = bus_find_device_by_name(
245			&platform_bus_type, NULL, "rtc_cmos");
246		if (rtc) {
247			pm_wakeup_event(rtc, 0);
248			put_device(rtc);
249		}
250	}
251
252	if (gpe & CS5536_GPIOM7_PME_FLAG) { /* EC GPIO */
253		cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_NEGATIVE_EDGE_STS);
254		schedule_work(&sci_work);
255	}
256
257	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
258	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
259	detect_lid_state();
260	send_lid_state();
261
262	return IRQ_HANDLED;
263}
264
265static int xo1_sci_suspend(struct platform_device *pdev, pm_message_t state)
266{
267	if (device_may_wakeup(&power_button_idev->dev))
268		olpc_xo1_pm_wakeup_set(CS5536_PM_PWRBTN);
269	else
270		olpc_xo1_pm_wakeup_clear(CS5536_PM_PWRBTN);
271
272	if (device_may_wakeup(&ebook_switch_idev->dev))
273		olpc_ec_wakeup_set(EC_SCI_SRC_EBOOK);
274	else
275		olpc_ec_wakeup_clear(EC_SCI_SRC_EBOOK);
276
277	if (!device_may_wakeup(&lid_switch_idev->dev)) {
278		cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
279	} else if ((lid_open && lid_wake_mode == LID_WAKE_OPEN) ||
280		   (!lid_open && lid_wake_mode == LID_WAKE_CLOSE)) {
281		flip_lid_inverter();
282
283		/* we may have just caused an event */
284		cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
285		cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
286
287		cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
288	}
289
290	return 0;
291}
292
293static int xo1_sci_resume(struct platform_device *pdev)
294{
295	/*
296	 * We don't know what may have happened while we were asleep.
297	 * Reestablish our lid setup so we're sure to catch all transitions.
298	 */
299	detect_lid_state();
300	send_lid_state();
301	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
302
303	/* Enable all EC events */
304	olpc_ec_mask_write(EC_SCI_SRC_ALL);
305
306	/* Power/battery status might have changed too */
307	battery_status_changed();
308	ac_status_changed();
309	return 0;
310}
311
312static int setup_sci_interrupt(struct platform_device *pdev)
313{
314	u32 lo, hi;
315	u32 sts;
316	int r;
317
318	rdmsr(0x51400020, lo, hi);
319	sci_irq = (lo >> 20) & 15;
320
321	if (sci_irq) {
322		dev_info(&pdev->dev, "SCI is mapped to IRQ %d\n", sci_irq);
323	} else {
324		/* Zero means masked */
325		dev_info(&pdev->dev, "SCI unmapped. Mapping to IRQ 3\n");
326		sci_irq = 3;
327		lo |= 0x00300000;
328		wrmsrl(0x51400020, lo);
329	}
330
331	/* Select level triggered in PIC */
332	if (sci_irq < 8) {
333		lo = inb(CS5536_PIC_INT_SEL1);
334		lo |= 1 << sci_irq;
335		outb(lo, CS5536_PIC_INT_SEL1);
336	} else {
337		lo = inb(CS5536_PIC_INT_SEL2);
338		lo |= 1 << (sci_irq - 8);
339		outb(lo, CS5536_PIC_INT_SEL2);
340	}
341
342	/* Enable interesting SCI events, and clear pending interrupts */
343	sts = inl(acpi_base + CS5536_PM1_STS);
344	outl(((CS5536_PM_PWRBTN | CS5536_PM_RTC) << 16) | 0xffff,
345	     acpi_base + CS5536_PM1_STS);
346
347	r = request_irq(sci_irq, xo1_sci_intr, 0, DRV_NAME, pdev);
348	if (r)
349		dev_err(&pdev->dev, "can't request interrupt\n");
350
351	return r;
352}
353
354static int setup_ec_sci(void)
355{
356	int r;
357
358	r = gpio_request(OLPC_GPIO_ECSCI, "OLPC-ECSCI");
359	if (r)
360		return r;
361
362	gpio_direction_input(OLPC_GPIO_ECSCI);
363
364	/* Clear pending EC SCI events */
365	cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_NEGATIVE_EDGE_STS);
366	cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_POSITIVE_EDGE_STS);
367
368	/*
369	 * Enable EC SCI events, and map them to both a PME and the SCI
370	 * interrupt.
371	 *
372	 * Ordinarily, in addition to functioning as GPIOs, Geode GPIOs can
373	 * be mapped to regular interrupts *or* Geode-specific Power
374	 * Management Events (PMEs) - events that bring the system out of
375	 * suspend. In this case, we want both of those things - the system
376	 * wakeup, *and* the ability to get an interrupt when an event occurs.
377	 *
378	 * To achieve this, we map the GPIO to a PME, and then we use one
379	 * of the many generic knobs on the CS5535 PIC to additionally map the
380	 * PME to the regular SCI interrupt line.
381	 */
382	cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_EVENTS_ENABLE);
383
384	/* Set the SCI to cause a PME event on group 7 */
385	cs5535_gpio_setup_event(OLPC_GPIO_ECSCI, 7, 1);
386
387	/* And have group 7 also fire the SCI interrupt */
388	cs5535_pic_unreqz_select_high(7, sci_irq);
389
390	return 0;
391}
392
393static void free_ec_sci(void)
394{
395	gpio_free(OLPC_GPIO_ECSCI);
396}
397
398static int setup_lid_events(void)
399{
400	int r;
401
402	r = gpio_request(OLPC_GPIO_LID, "OLPC-LID");
403	if (r)
404		return r;
405
406	gpio_direction_input(OLPC_GPIO_LID);
407
408	cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
409	lid_inverted = 0;
410
411	/* Clear edge detection and event enable for now */
412	cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
413	cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_EN);
414	cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_EN);
415	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
416	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
417
418	/* Set the LID to cause an PME event on group 6 */
419	cs5535_gpio_setup_event(OLPC_GPIO_LID, 6, 1);
420
421	/* Set PME group 6 to fire the SCI interrupt */
422	cs5535_gpio_set_irq(6, sci_irq);
423
424	/* Enable the event */
425	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
426
427	return 0;
428}
429
430static void free_lid_events(void)
431{
432	gpio_free(OLPC_GPIO_LID);
433}
434
435static int setup_power_button(struct platform_device *pdev)
436{
437	int r;
438
439	power_button_idev = input_allocate_device();
440	if (!power_button_idev)
441		return -ENOMEM;
442
443	power_button_idev->name = "Power Button";
444	power_button_idev->phys = DRV_NAME "/input0";
445	set_bit(EV_KEY, power_button_idev->evbit);
446	set_bit(KEY_POWER, power_button_idev->keybit);
447
448	power_button_idev->dev.parent = &pdev->dev;
449	device_init_wakeup(&power_button_idev->dev, 1);
450
451	r = input_register_device(power_button_idev);
452	if (r) {
453		dev_err(&pdev->dev, "failed to register power button: %d\n", r);
454		input_free_device(power_button_idev);
455	}
456
457	return r;
458}
459
460static void free_power_button(void)
461{
462	input_unregister_device(power_button_idev);
463}
464
465static int setup_ebook_switch(struct platform_device *pdev)
466{
467	int r;
468
469	ebook_switch_idev = input_allocate_device();
470	if (!ebook_switch_idev)
471		return -ENOMEM;
472
473	ebook_switch_idev->name = "EBook Switch";
474	ebook_switch_idev->phys = DRV_NAME "/input1";
475	set_bit(EV_SW, ebook_switch_idev->evbit);
476	set_bit(SW_TABLET_MODE, ebook_switch_idev->swbit);
477
478	ebook_switch_idev->dev.parent = &pdev->dev;
479	device_set_wakeup_capable(&ebook_switch_idev->dev, true);
480
481	r = input_register_device(ebook_switch_idev);
482	if (r) {
483		dev_err(&pdev->dev, "failed to register ebook switch: %d\n", r);
484		input_free_device(ebook_switch_idev);
485	}
486
487	return r;
488}
489
490static void free_ebook_switch(void)
491{
492	input_unregister_device(ebook_switch_idev);
493}
494
495static int setup_lid_switch(struct platform_device *pdev)
496{
497	int r;
498
499	lid_switch_idev = input_allocate_device();
500	if (!lid_switch_idev)
501		return -ENOMEM;
502
503	lid_switch_idev->name = "Lid Switch";
504	lid_switch_idev->phys = DRV_NAME "/input2";
505	set_bit(EV_SW, lid_switch_idev->evbit);
506	set_bit(SW_LID, lid_switch_idev->swbit);
507
508	lid_switch_idev->dev.parent = &pdev->dev;
509	device_set_wakeup_capable(&lid_switch_idev->dev, true);
510
511	r = input_register_device(lid_switch_idev);
512	if (r) {
513		dev_err(&pdev->dev, "failed to register lid switch: %d\n", r);
514		goto err_register;
515	}
516
517	r = device_create_file(&lid_switch_idev->dev, &dev_attr_lid_wake_mode);
518	if (r) {
519		dev_err(&pdev->dev, "failed to create wake mode attr: %d\n", r);
520		goto err_create_attr;
521	}
522
523	return 0;
524
525err_create_attr:
526	input_unregister_device(lid_switch_idev);
527	lid_switch_idev = NULL;
528err_register:
529	input_free_device(lid_switch_idev);
530	return r;
531}
532
533static void free_lid_switch(void)
534{
535	device_remove_file(&lid_switch_idev->dev, &dev_attr_lid_wake_mode);
536	input_unregister_device(lid_switch_idev);
537}
538
539static int xo1_sci_probe(struct platform_device *pdev)
540{
541	struct resource *res;
542	int r;
543
544	/* don't run on non-XOs */
545	if (!machine_is_olpc())
546		return -ENODEV;
547
548	r = mfd_cell_enable(pdev);
549	if (r)
550		return r;
551
552	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
553	if (!res) {
554		dev_err(&pdev->dev, "can't fetch device resource info\n");
555		return -EIO;
556	}
557	acpi_base = res->start;
558
559	r = setup_power_button(pdev);
560	if (r)
561		return r;
562
563	r = setup_ebook_switch(pdev);
564	if (r)
565		goto err_ebook;
566
567	r = setup_lid_switch(pdev);
568	if (r)
569		goto err_lid;
570
571	r = setup_lid_events();
572	if (r)
573		goto err_lidevt;
574
575	r = setup_ec_sci();
576	if (r)
577		goto err_ecsci;
578
579	/* Enable PME generation for EC-generated events */
580	outl(CS5536_GPIOM6_PME_EN | CS5536_GPIOM7_PME_EN,
581		acpi_base + CS5536_PM_GPE0_EN);
582
583	/* Clear pending events */
584	outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
585	process_sci_queue(false);
586
587	/* Initial sync */
588	send_ebook_state();
589	detect_lid_state();
590	send_lid_state();
591
592	r = setup_sci_interrupt(pdev);
593	if (r)
594		goto err_sci;
595
596	/* Enable all EC events */
597	olpc_ec_mask_write(EC_SCI_SRC_ALL);
598
599	return r;
600
601err_sci:
602	free_ec_sci();
603err_ecsci:
604	free_lid_events();
605err_lidevt:
606	free_lid_switch();
607err_lid:
608	free_ebook_switch();
609err_ebook:
610	free_power_button();
611	return r;
612}
613
614static int xo1_sci_remove(struct platform_device *pdev)
615{
616	mfd_cell_disable(pdev);
617	free_irq(sci_irq, pdev);
618	cancel_work_sync(&sci_work);
619	free_ec_sci();
620	free_lid_events();
621	free_lid_switch();
622	free_ebook_switch();
623	free_power_button();
624	acpi_base = 0;
625	return 0;
626}
627
628static struct platform_driver xo1_sci_driver = {
629	.driver = {
630		.name = "olpc-xo1-sci-acpi",
631	},
632	.probe = xo1_sci_probe,
633	.remove = xo1_sci_remove,
634	.suspend = xo1_sci_suspend,
635	.resume = xo1_sci_resume,
636};
637
638static int __init xo1_sci_init(void)
639{
640	return platform_driver_register(&xo1_sci_driver);
641}
642arch_initcall(xo1_sci_init);
643