xref: /linux/arch/x86/platform/olpc/olpc-xo1-sci.c (revision fc6bdb59a501740b28ed3b616641a22c8dc5dd31)
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 
35 static unsigned long acpi_base;
36 static struct input_dev *power_button_idev;
37 static struct input_dev *ebook_switch_idev;
38 static struct input_dev *lid_switch_idev;
39 
40 static int sci_irq;
41 
42 static bool lid_open;
43 static bool lid_inverted;
44 static int lid_wake_mode;
45 
46 enum lid_wake_modes {
47 	LID_WAKE_ALWAYS,
48 	LID_WAKE_OPEN,
49 	LID_WAKE_CLOSE,
50 };
51 
52 static const char * const lid_wake_mode_names[] = {
53 	[LID_WAKE_ALWAYS] = "always",
54 	[LID_WAKE_OPEN] = "open",
55 	[LID_WAKE_CLOSE] = "close",
56 };
57 
58 static 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 		put_device(psy->dev);
65 	}
66 }
67 
68 static 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 		put_device(psy->dev);
75 	}
76 }
77 
78 /* Report current ebook switch state through input layer */
79 static 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 
96 static 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 
106 static 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 */
130 static 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 
140 static 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 }
146 static 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 }
161 static 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  */
173 static 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 
205 static void process_sci_queue_work(struct work_struct *work)
206 {
207 	process_sci_queue(true);
208 }
209 
210 static DECLARE_WORK(sci_work, process_sci_queue_work);
211 
212 static 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 
265 static 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 
293 static 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 
312 static int __devinit 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 
354 static int __devinit 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 
393 static void free_ec_sci(void)
394 {
395 	gpio_free(OLPC_GPIO_ECSCI);
396 }
397 
398 static int __devinit 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 
430 static void free_lid_events(void)
431 {
432 	gpio_free(OLPC_GPIO_LID);
433 }
434 
435 static int __devinit 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 
460 static void free_power_button(void)
461 {
462 	input_unregister_device(power_button_idev);
463 	input_free_device(power_button_idev);
464 }
465 
466 static int __devinit setup_ebook_switch(struct platform_device *pdev)
467 {
468 	int r;
469 
470 	ebook_switch_idev = input_allocate_device();
471 	if (!ebook_switch_idev)
472 		return -ENOMEM;
473 
474 	ebook_switch_idev->name = "EBook Switch";
475 	ebook_switch_idev->phys = DRV_NAME "/input1";
476 	set_bit(EV_SW, ebook_switch_idev->evbit);
477 	set_bit(SW_TABLET_MODE, ebook_switch_idev->swbit);
478 
479 	ebook_switch_idev->dev.parent = &pdev->dev;
480 	device_set_wakeup_capable(&ebook_switch_idev->dev, true);
481 
482 	r = input_register_device(ebook_switch_idev);
483 	if (r) {
484 		dev_err(&pdev->dev, "failed to register ebook switch: %d\n", r);
485 		input_free_device(ebook_switch_idev);
486 	}
487 
488 	return r;
489 }
490 
491 static void free_ebook_switch(void)
492 {
493 	input_unregister_device(ebook_switch_idev);
494 	input_free_device(ebook_switch_idev);
495 }
496 
497 static int __devinit setup_lid_switch(struct platform_device *pdev)
498 {
499 	int r;
500 
501 	lid_switch_idev = input_allocate_device();
502 	if (!lid_switch_idev)
503 		return -ENOMEM;
504 
505 	lid_switch_idev->name = "Lid Switch";
506 	lid_switch_idev->phys = DRV_NAME "/input2";
507 	set_bit(EV_SW, lid_switch_idev->evbit);
508 	set_bit(SW_LID, lid_switch_idev->swbit);
509 
510 	lid_switch_idev->dev.parent = &pdev->dev;
511 	device_set_wakeup_capable(&lid_switch_idev->dev, true);
512 
513 	r = input_register_device(lid_switch_idev);
514 	if (r) {
515 		dev_err(&pdev->dev, "failed to register lid switch: %d\n", r);
516 		goto err_register;
517 	}
518 
519 	r = device_create_file(&lid_switch_idev->dev, &dev_attr_lid_wake_mode);
520 	if (r) {
521 		dev_err(&pdev->dev, "failed to create wake mode attr: %d\n", r);
522 		goto err_create_attr;
523 	}
524 
525 	return 0;
526 
527 err_create_attr:
528 	input_unregister_device(lid_switch_idev);
529 err_register:
530 	input_free_device(lid_switch_idev);
531 	return r;
532 }
533 
534 static void free_lid_switch(void)
535 {
536 	device_remove_file(&lid_switch_idev->dev, &dev_attr_lid_wake_mode);
537 	input_unregister_device(lid_switch_idev);
538 	input_free_device(lid_switch_idev);
539 }
540 
541 static int __devinit xo1_sci_probe(struct platform_device *pdev)
542 {
543 	struct resource *res;
544 	int r;
545 
546 	/* don't run on non-XOs */
547 	if (!machine_is_olpc())
548 		return -ENODEV;
549 
550 	r = mfd_cell_enable(pdev);
551 	if (r)
552 		return r;
553 
554 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
555 	if (!res) {
556 		dev_err(&pdev->dev, "can't fetch device resource info\n");
557 		return -EIO;
558 	}
559 	acpi_base = res->start;
560 
561 	r = setup_power_button(pdev);
562 	if (r)
563 		return r;
564 
565 	r = setup_ebook_switch(pdev);
566 	if (r)
567 		goto err_ebook;
568 
569 	r = setup_lid_switch(pdev);
570 	if (r)
571 		goto err_lid;
572 
573 	r = setup_lid_events();
574 	if (r)
575 		goto err_lidevt;
576 
577 	r = setup_ec_sci();
578 	if (r)
579 		goto err_ecsci;
580 
581 	/* Enable PME generation for EC-generated events */
582 	outl(CS5536_GPIOM6_PME_EN | CS5536_GPIOM7_PME_EN,
583 		acpi_base + CS5536_PM_GPE0_EN);
584 
585 	/* Clear pending events */
586 	outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
587 	process_sci_queue(false);
588 
589 	/* Initial sync */
590 	send_ebook_state();
591 	detect_lid_state();
592 	send_lid_state();
593 
594 	r = setup_sci_interrupt(pdev);
595 	if (r)
596 		goto err_sci;
597 
598 	/* Enable all EC events */
599 	olpc_ec_mask_write(EC_SCI_SRC_ALL);
600 
601 	return r;
602 
603 err_sci:
604 	free_ec_sci();
605 err_ecsci:
606 	free_lid_events();
607 err_lidevt:
608 	free_lid_switch();
609 err_lid:
610 	free_ebook_switch();
611 err_ebook:
612 	free_power_button();
613 	return r;
614 }
615 
616 static int __devexit xo1_sci_remove(struct platform_device *pdev)
617 {
618 	mfd_cell_disable(pdev);
619 	free_irq(sci_irq, pdev);
620 	cancel_work_sync(&sci_work);
621 	free_ec_sci();
622 	free_lid_events();
623 	free_lid_switch();
624 	free_ebook_switch();
625 	free_power_button();
626 	acpi_base = 0;
627 	return 0;
628 }
629 
630 static struct platform_driver xo1_sci_driver = {
631 	.driver = {
632 		.name = "olpc-xo1-sci-acpi",
633 	},
634 	.probe = xo1_sci_probe,
635 	.remove = __devexit_p(xo1_sci_remove),
636 	.suspend = xo1_sci_suspend,
637 	.resume = xo1_sci_resume,
638 };
639 
640 static int __init xo1_sci_init(void)
641 {
642 	return platform_driver_register(&xo1_sci_driver);
643 }
644 arch_initcall(xo1_sci_init);
645