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 
27 #include <asm/io.h>
28 #include <asm/msr.h>
29 #include <asm/olpc.h>
30 
31 #define DRV_NAME	"olpc-xo1-sci"
32 #define PFX		DRV_NAME ": "
33 
34 static unsigned long acpi_base;
35 static struct input_dev *power_button_idev;
36 static struct input_dev *ebook_switch_idev;
37 static struct input_dev *lid_switch_idev;
38 
39 static int sci_irq;
40 
41 static bool lid_open;
42 static bool lid_inverted;
43 static int lid_wake_mode;
44 
45 enum lid_wake_modes {
46 	LID_WAKE_ALWAYS,
47 	LID_WAKE_OPEN,
48 	LID_WAKE_CLOSE,
49 };
50 
51 static const char * const lid_wake_mode_names[] = {
52 	[LID_WAKE_ALWAYS] = "always",
53 	[LID_WAKE_OPEN] = "open",
54 	[LID_WAKE_CLOSE] = "close",
55 };
56 
57 static void battery_status_changed(void)
58 {
59 	struct power_supply *psy = power_supply_get_by_name("olpc-battery");
60 
61 	if (psy) {
62 		power_supply_changed(psy);
63 		put_device(psy->dev);
64 	}
65 }
66 
67 static void ac_status_changed(void)
68 {
69 	struct power_supply *psy = power_supply_get_by_name("olpc-ac");
70 
71 	if (psy) {
72 		power_supply_changed(psy);
73 		put_device(psy->dev);
74 	}
75 }
76 
77 /* Report current ebook switch state through input layer */
78 static void send_ebook_state(void)
79 {
80 	unsigned char state;
81 
82 	if (olpc_ec_cmd(EC_READ_EB_MODE, NULL, 0, &state, 1)) {
83 		pr_err(PFX "failed to get ebook state\n");
84 		return;
85 	}
86 
87 	if (!!test_bit(SW_TABLET_MODE, ebook_switch_idev->sw) == state)
88 		return; /* Nothing new to report. */
89 
90 	input_report_switch(ebook_switch_idev, SW_TABLET_MODE, state);
91 	input_sync(ebook_switch_idev);
92 	pm_wakeup_event(&ebook_switch_idev->dev, 0);
93 }
94 
95 static void flip_lid_inverter(void)
96 {
97 	/* gpio is high; invert so we'll get l->h event interrupt */
98 	if (lid_inverted)
99 		cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
100 	else
101 		cs5535_gpio_set(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
102 	lid_inverted = !lid_inverted;
103 }
104 
105 static void detect_lid_state(void)
106 {
107 	/*
108 	 * the edge detector hookup on the gpio inputs on the geode is
109 	 * odd, to say the least.  See http://dev.laptop.org/ticket/5703
110 	 * for details, but in a nutshell:  we don't use the edge
111 	 * detectors.  instead, we make use of an anomoly:  with the both
112 	 * edge detectors turned off, we still get an edge event on a
113 	 * positive edge transition.  to take advantage of this, we use the
114 	 * front-end inverter to ensure that that's the edge we're always
115 	 * going to see next.
116 	 */
117 
118 	int state;
119 
120 	state = cs5535_gpio_isset(OLPC_GPIO_LID, GPIO_READ_BACK);
121 	lid_open = !state ^ !lid_inverted; /* x ^^ y */
122 	if (!state)
123 		return;
124 
125 	flip_lid_inverter();
126 }
127 
128 /* Report current lid switch state through input layer */
129 static void send_lid_state(void)
130 {
131 	if (!!test_bit(SW_LID, lid_switch_idev->sw) == !lid_open)
132 		return; /* Nothing new to report. */
133 
134 	input_report_switch(lid_switch_idev, SW_LID, !lid_open);
135 	input_sync(lid_switch_idev);
136 	pm_wakeup_event(&lid_switch_idev->dev, 0);
137 }
138 
139 static ssize_t lid_wake_mode_show(struct device *dev,
140 				  struct device_attribute *attr, char *buf)
141 {
142 	const char *mode = lid_wake_mode_names[lid_wake_mode];
143 	return sprintf(buf, "%s\n", mode);
144 }
145 static ssize_t lid_wake_mode_set(struct device *dev,
146 				 struct device_attribute *attr,
147 				 const char *buf, size_t count)
148 {
149 	int i;
150 	for (i = 0; i < ARRAY_SIZE(lid_wake_mode_names); i++) {
151 		const char *mode = lid_wake_mode_names[i];
152 		if (strlen(mode) != count || strncasecmp(mode, buf, count))
153 			continue;
154 
155 		lid_wake_mode = i;
156 		return count;
157 	}
158 	return -EINVAL;
159 }
160 static DEVICE_ATTR(lid_wake_mode, S_IWUSR | S_IRUGO, lid_wake_mode_show,
161 		   lid_wake_mode_set);
162 
163 /*
164  * Process all items in the EC's SCI queue.
165  *
166  * This is handled in a workqueue because olpc_ec_cmd can be slow (and
167  * can even timeout).
168  *
169  * If propagate_events is false, the queue is drained without events being
170  * generated for the interrupts.
171  */
172 static void process_sci_queue(bool propagate_events)
173 {
174 	int r;
175 	u16 data;
176 
177 	do {
178 		r = olpc_ec_sci_query(&data);
179 		if (r || !data)
180 			break;
181 
182 		pr_debug(PFX "SCI 0x%x received\n", data);
183 
184 		switch (data) {
185 		case EC_SCI_SRC_BATERR:
186 		case EC_SCI_SRC_BATSOC:
187 		case EC_SCI_SRC_BATTERY:
188 		case EC_SCI_SRC_BATCRIT:
189 			battery_status_changed();
190 			break;
191 		case EC_SCI_SRC_ACPWR:
192 			ac_status_changed();
193 			break;
194 		}
195 
196 		if (data == EC_SCI_SRC_EBOOK && propagate_events)
197 			send_ebook_state();
198 	} while (data);
199 
200 	if (r)
201 		pr_err(PFX "Failed to clear SCI queue");
202 }
203 
204 static void process_sci_queue_work(struct work_struct *work)
205 {
206 	process_sci_queue(true);
207 }
208 
209 static DECLARE_WORK(sci_work, process_sci_queue_work);
210 
211 static irqreturn_t xo1_sci_intr(int irq, void *dev_id)
212 {
213 	struct platform_device *pdev = dev_id;
214 	u32 sts;
215 	u32 gpe;
216 
217 	sts = inl(acpi_base + CS5536_PM1_STS);
218 	outl(sts | 0xffff, acpi_base + CS5536_PM1_STS);
219 
220 	gpe = inl(acpi_base + CS5536_PM_GPE0_STS);
221 	outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
222 
223 	dev_dbg(&pdev->dev, "sts %x gpe %x\n", sts, gpe);
224 
225 	if (sts & CS5536_PWRBTN_FLAG) {
226 		if (!(sts & CS5536_WAK_FLAG)) {
227 			/* Only report power button input when it was pressed
228 			 * during regular operation (as opposed to when it
229 			 * was used to wake the system). */
230 			input_report_key(power_button_idev, KEY_POWER, 1);
231 			input_sync(power_button_idev);
232 			input_report_key(power_button_idev, KEY_POWER, 0);
233 			input_sync(power_button_idev);
234 		}
235 		/* Report the wakeup event in all cases. */
236 		pm_wakeup_event(&power_button_idev->dev, 0);
237 	}
238 
239 	if ((sts & (CS5536_RTC_FLAG | CS5536_WAK_FLAG)) ==
240 			(CS5536_RTC_FLAG | CS5536_WAK_FLAG)) {
241 		/* When the system is woken by the RTC alarm, report the
242 		 * event on the rtc device. */
243 		struct device *rtc = bus_find_device_by_name(
244 			&platform_bus_type, NULL, "rtc_cmos");
245 		if (rtc) {
246 			pm_wakeup_event(rtc, 0);
247 			put_device(rtc);
248 		}
249 	}
250 
251 	if (gpe & CS5536_GPIOM7_PME_FLAG) { /* EC GPIO */
252 		cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_NEGATIVE_EDGE_STS);
253 		schedule_work(&sci_work);
254 	}
255 
256 	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
257 	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
258 	detect_lid_state();
259 	send_lid_state();
260 
261 	return IRQ_HANDLED;
262 }
263 
264 static int xo1_sci_suspend(struct platform_device *pdev, pm_message_t state)
265 {
266 	if (device_may_wakeup(&power_button_idev->dev))
267 		olpc_xo1_pm_wakeup_set(CS5536_PM_PWRBTN);
268 	else
269 		olpc_xo1_pm_wakeup_clear(CS5536_PM_PWRBTN);
270 
271 	if (device_may_wakeup(&ebook_switch_idev->dev))
272 		olpc_ec_wakeup_set(EC_SCI_SRC_EBOOK);
273 	else
274 		olpc_ec_wakeup_clear(EC_SCI_SRC_EBOOK);
275 
276 	if (!device_may_wakeup(&lid_switch_idev->dev)) {
277 		cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
278 	} else if ((lid_open && lid_wake_mode == LID_WAKE_OPEN) ||
279 		   (!lid_open && lid_wake_mode == LID_WAKE_CLOSE)) {
280 		flip_lid_inverter();
281 
282 		/* we may have just caused an event */
283 		cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
284 		cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
285 
286 		cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
287 	}
288 
289 	return 0;
290 }
291 
292 static int xo1_sci_resume(struct platform_device *pdev)
293 {
294 	/*
295 	 * We don't know what may have happened while we were asleep.
296 	 * Reestablish our lid setup so we're sure to catch all transitions.
297 	 */
298 	detect_lid_state();
299 	send_lid_state();
300 	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
301 
302 	/* Enable all EC events */
303 	olpc_ec_mask_write(EC_SCI_SRC_ALL);
304 
305 	/* Power/battery status might have changed too */
306 	battery_status_changed();
307 	ac_status_changed();
308 	return 0;
309 }
310 
311 static int __devinit setup_sci_interrupt(struct platform_device *pdev)
312 {
313 	u32 lo, hi;
314 	u32 sts;
315 	int r;
316 
317 	rdmsr(0x51400020, lo, hi);
318 	sci_irq = (lo >> 20) & 15;
319 
320 	if (sci_irq) {
321 		dev_info(&pdev->dev, "SCI is mapped to IRQ %d\n", sci_irq);
322 	} else {
323 		/* Zero means masked */
324 		dev_info(&pdev->dev, "SCI unmapped. Mapping to IRQ 3\n");
325 		sci_irq = 3;
326 		lo |= 0x00300000;
327 		wrmsrl(0x51400020, lo);
328 	}
329 
330 	/* Select level triggered in PIC */
331 	if (sci_irq < 8) {
332 		lo = inb(CS5536_PIC_INT_SEL1);
333 		lo |= 1 << sci_irq;
334 		outb(lo, CS5536_PIC_INT_SEL1);
335 	} else {
336 		lo = inb(CS5536_PIC_INT_SEL2);
337 		lo |= 1 << (sci_irq - 8);
338 		outb(lo, CS5536_PIC_INT_SEL2);
339 	}
340 
341 	/* Enable interesting SCI events, and clear pending interrupts */
342 	sts = inl(acpi_base + CS5536_PM1_STS);
343 	outl(((CS5536_PM_PWRBTN | CS5536_PM_RTC) << 16) | 0xffff,
344 	     acpi_base + CS5536_PM1_STS);
345 
346 	r = request_irq(sci_irq, xo1_sci_intr, 0, DRV_NAME, pdev);
347 	if (r)
348 		dev_err(&pdev->dev, "can't request interrupt\n");
349 
350 	return r;
351 }
352 
353 static int __devinit setup_ec_sci(void)
354 {
355 	int r;
356 
357 	r = gpio_request(OLPC_GPIO_ECSCI, "OLPC-ECSCI");
358 	if (r)
359 		return r;
360 
361 	gpio_direction_input(OLPC_GPIO_ECSCI);
362 
363 	/* Clear pending EC SCI events */
364 	cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_NEGATIVE_EDGE_STS);
365 	cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_POSITIVE_EDGE_STS);
366 
367 	/*
368 	 * Enable EC SCI events, and map them to both a PME and the SCI
369 	 * interrupt.
370 	 *
371 	 * Ordinarily, in addition to functioning as GPIOs, Geode GPIOs can
372 	 * be mapped to regular interrupts *or* Geode-specific Power
373 	 * Management Events (PMEs) - events that bring the system out of
374 	 * suspend. In this case, we want both of those things - the system
375 	 * wakeup, *and* the ability to get an interrupt when an event occurs.
376 	 *
377 	 * To achieve this, we map the GPIO to a PME, and then we use one
378 	 * of the many generic knobs on the CS5535 PIC to additionally map the
379 	 * PME to the regular SCI interrupt line.
380 	 */
381 	cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_EVENTS_ENABLE);
382 
383 	/* Set the SCI to cause a PME event on group 7 */
384 	cs5535_gpio_setup_event(OLPC_GPIO_ECSCI, 7, 1);
385 
386 	/* And have group 7 also fire the SCI interrupt */
387 	cs5535_pic_unreqz_select_high(7, sci_irq);
388 
389 	return 0;
390 }
391 
392 static void free_ec_sci(void)
393 {
394 	gpio_free(OLPC_GPIO_ECSCI);
395 }
396 
397 static int __devinit setup_lid_events(void)
398 {
399 	int r;
400 
401 	r = gpio_request(OLPC_GPIO_LID, "OLPC-LID");
402 	if (r)
403 		return r;
404 
405 	gpio_direction_input(OLPC_GPIO_LID);
406 
407 	cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
408 	lid_inverted = 0;
409 
410 	/* Clear edge detection and event enable for now */
411 	cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
412 	cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_EN);
413 	cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_EN);
414 	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
415 	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
416 
417 	/* Set the LID to cause an PME event on group 6 */
418 	cs5535_gpio_setup_event(OLPC_GPIO_LID, 6, 1);
419 
420 	/* Set PME group 6 to fire the SCI interrupt */
421 	cs5535_gpio_set_irq(6, sci_irq);
422 
423 	/* Enable the event */
424 	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
425 
426 	return 0;
427 }
428 
429 static void free_lid_events(void)
430 {
431 	gpio_free(OLPC_GPIO_LID);
432 }
433 
434 static int __devinit setup_power_button(struct platform_device *pdev)
435 {
436 	int r;
437 
438 	power_button_idev = input_allocate_device();
439 	if (!power_button_idev)
440 		return -ENOMEM;
441 
442 	power_button_idev->name = "Power Button";
443 	power_button_idev->phys = DRV_NAME "/input0";
444 	set_bit(EV_KEY, power_button_idev->evbit);
445 	set_bit(KEY_POWER, power_button_idev->keybit);
446 
447 	power_button_idev->dev.parent = &pdev->dev;
448 	device_init_wakeup(&power_button_idev->dev, 1);
449 
450 	r = input_register_device(power_button_idev);
451 	if (r) {
452 		dev_err(&pdev->dev, "failed to register power button: %d\n", r);
453 		input_free_device(power_button_idev);
454 	}
455 
456 	return r;
457 }
458 
459 static void free_power_button(void)
460 {
461 	input_unregister_device(power_button_idev);
462 	input_free_device(power_button_idev);
463 }
464 
465 static int __devinit 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 
490 static void free_ebook_switch(void)
491 {
492 	input_unregister_device(ebook_switch_idev);
493 	input_free_device(ebook_switch_idev);
494 }
495 
496 static int __devinit setup_lid_switch(struct platform_device *pdev)
497 {
498 	int r;
499 
500 	lid_switch_idev = input_allocate_device();
501 	if (!lid_switch_idev)
502 		return -ENOMEM;
503 
504 	lid_switch_idev->name = "Lid Switch";
505 	lid_switch_idev->phys = DRV_NAME "/input2";
506 	set_bit(EV_SW, lid_switch_idev->evbit);
507 	set_bit(SW_LID, lid_switch_idev->swbit);
508 
509 	lid_switch_idev->dev.parent = &pdev->dev;
510 	device_set_wakeup_capable(&lid_switch_idev->dev, true);
511 
512 	r = input_register_device(lid_switch_idev);
513 	if (r) {
514 		dev_err(&pdev->dev, "failed to register lid switch: %d\n", r);
515 		goto err_register;
516 	}
517 
518 	r = device_create_file(&lid_switch_idev->dev, &dev_attr_lid_wake_mode);
519 	if (r) {
520 		dev_err(&pdev->dev, "failed to create wake mode attr: %d\n", r);
521 		goto err_create_attr;
522 	}
523 
524 	return 0;
525 
526 err_create_attr:
527 	input_unregister_device(lid_switch_idev);
528 err_register:
529 	input_free_device(lid_switch_idev);
530 	return r;
531 }
532 
533 static 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 	input_free_device(lid_switch_idev);
538 }
539 
540 static int __devinit xo1_sci_probe(struct platform_device *pdev)
541 {
542 	struct resource *res;
543 	int r;
544 
545 	/* don't run on non-XOs */
546 	if (!machine_is_olpc())
547 		return -ENODEV;
548 
549 	r = mfd_cell_enable(pdev);
550 	if (r)
551 		return r;
552 
553 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
554 	if (!res) {
555 		dev_err(&pdev->dev, "can't fetch device resource info\n");
556 		return -EIO;
557 	}
558 	acpi_base = res->start;
559 
560 	r = setup_power_button(pdev);
561 	if (r)
562 		return r;
563 
564 	r = setup_ebook_switch(pdev);
565 	if (r)
566 		goto err_ebook;
567 
568 	r = setup_lid_switch(pdev);
569 	if (r)
570 		goto err_lid;
571 
572 	r = setup_lid_events();
573 	if (r)
574 		goto err_lidevt;
575 
576 	r = setup_ec_sci();
577 	if (r)
578 		goto err_ecsci;
579 
580 	/* Enable PME generation for EC-generated events */
581 	outl(CS5536_GPIOM6_PME_EN | CS5536_GPIOM7_PME_EN,
582 		acpi_base + CS5536_PM_GPE0_EN);
583 
584 	/* Clear pending events */
585 	outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
586 	process_sci_queue(false);
587 
588 	/* Initial sync */
589 	send_ebook_state();
590 	detect_lid_state();
591 	send_lid_state();
592 
593 	r = setup_sci_interrupt(pdev);
594 	if (r)
595 		goto err_sci;
596 
597 	/* Enable all EC events */
598 	olpc_ec_mask_write(EC_SCI_SRC_ALL);
599 
600 	return r;
601 
602 err_sci:
603 	free_ec_sci();
604 err_ecsci:
605 	free_lid_events();
606 err_lidevt:
607 	free_lid_switch();
608 err_lid:
609 	free_ebook_switch();
610 err_ebook:
611 	free_power_button();
612 	return r;
613 }
614 
615 static int __devexit xo1_sci_remove(struct platform_device *pdev)
616 {
617 	mfd_cell_disable(pdev);
618 	free_irq(sci_irq, pdev);
619 	cancel_work_sync(&sci_work);
620 	free_ec_sci();
621 	free_lid_events();
622 	free_lid_switch();
623 	free_ebook_switch();
624 	free_power_button();
625 	acpi_base = 0;
626 	return 0;
627 }
628 
629 static struct platform_driver xo1_sci_driver = {
630 	.driver = {
631 		.name = "olpc-xo1-sci-acpi",
632 	},
633 	.probe = xo1_sci_probe,
634 	.remove = __devexit_p(xo1_sci_remove),
635 	.suspend = xo1_sci_suspend,
636 	.resume = xo1_sci_resume,
637 };
638 
639 static int __init xo1_sci_init(void)
640 {
641 	return platform_driver_register(&xo1_sci_driver);
642 }
643 arch_initcall(xo1_sci_init);
644