1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Support for OLPC XO-1 System Control Interrupts (SCI)
4  *
5  * Copyright (C) 2010 One Laptop per Child
6  * Copyright (C) 2006 Red Hat, Inc.
7  * Copyright (C) 2006 Advanced Micro Devices, Inc.
8  */
9 
10 #include <linux/cs5535.h>
11 #include <linux/device.h>
12 #include <linux/gpio.h>
13 #include <linux/input.h>
14 #include <linux/interrupt.h>
15 #include <linux/platform_device.h>
16 #include <linux/pm.h>
17 #include <linux/pm_wakeup.h>
18 #include <linux/power_supply.h>
19 #include <linux/suspend.h>
20 #include <linux/workqueue.h>
21 #include <linux/olpc-ec.h>
22 
23 #include <asm/io.h>
24 #include <asm/msr.h>
25 #include <asm/olpc.h>
26 
27 #define DRV_NAME	"olpc-xo1-sci"
28 #define PFX		DRV_NAME ": "
29 
30 static unsigned long acpi_base;
31 static struct input_dev *power_button_idev;
32 static struct input_dev *ebook_switch_idev;
33 static struct input_dev *lid_switch_idev;
34 
35 static int sci_irq;
36 
37 static bool lid_open;
38 static bool lid_inverted;
39 static int lid_wake_mode;
40 
41 enum lid_wake_modes {
42 	LID_WAKE_ALWAYS,
43 	LID_WAKE_OPEN,
44 	LID_WAKE_CLOSE,
45 };
46 
47 static const char * const lid_wake_mode_names[] = {
48 	[LID_WAKE_ALWAYS] = "always",
49 	[LID_WAKE_OPEN] = "open",
50 	[LID_WAKE_CLOSE] = "close",
51 };
52 
53 static void battery_status_changed(void)
54 {
55 	struct power_supply *psy = power_supply_get_by_name("olpc_battery");
56 
57 	if (psy) {
58 		power_supply_changed(psy);
59 		power_supply_put(psy);
60 	}
61 }
62 
63 static void ac_status_changed(void)
64 {
65 	struct power_supply *psy = power_supply_get_by_name("olpc_ac");
66 
67 	if (psy) {
68 		power_supply_changed(psy);
69 		power_supply_put(psy);
70 	}
71 }
72 
73 /* Report current ebook switch state through input layer */
74 static void send_ebook_state(void)
75 {
76 	unsigned char state;
77 
78 	if (olpc_ec_cmd(EC_READ_EB_MODE, NULL, 0, &state, 1)) {
79 		pr_err(PFX "failed to get ebook state\n");
80 		return;
81 	}
82 
83 	if (!!test_bit(SW_TABLET_MODE, ebook_switch_idev->sw) == state)
84 		return; /* Nothing new to report. */
85 
86 	input_report_switch(ebook_switch_idev, SW_TABLET_MODE, state);
87 	input_sync(ebook_switch_idev);
88 	pm_wakeup_event(&ebook_switch_idev->dev, 0);
89 }
90 
91 static void flip_lid_inverter(void)
92 {
93 	/* gpio is high; invert so we'll get l->h event interrupt */
94 	if (lid_inverted)
95 		cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
96 	else
97 		cs5535_gpio_set(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
98 	lid_inverted = !lid_inverted;
99 }
100 
101 static void detect_lid_state(void)
102 {
103 	/*
104 	 * the edge detector hookup on the gpio inputs on the geode is
105 	 * odd, to say the least.  See http://dev.laptop.org/ticket/5703
106 	 * for details, but in a nutshell:  we don't use the edge
107 	 * detectors.  instead, we make use of an anomaly:  with the both
108 	 * edge detectors turned off, we still get an edge event on a
109 	 * positive edge transition.  to take advantage of this, we use the
110 	 * front-end inverter to ensure that that's the edge we're always
111 	 * going to see next.
112 	 */
113 
114 	int state;
115 
116 	state = cs5535_gpio_isset(OLPC_GPIO_LID, GPIO_READ_BACK);
117 	lid_open = !state ^ !lid_inverted; /* x ^^ y */
118 	if (!state)
119 		return;
120 
121 	flip_lid_inverter();
122 }
123 
124 /* Report current lid switch state through input layer */
125 static void send_lid_state(void)
126 {
127 	if (!!test_bit(SW_LID, lid_switch_idev->sw) == !lid_open)
128 		return; /* Nothing new to report. */
129 
130 	input_report_switch(lid_switch_idev, SW_LID, !lid_open);
131 	input_sync(lid_switch_idev);
132 	pm_wakeup_event(&lid_switch_idev->dev, 0);
133 }
134 
135 static ssize_t lid_wake_mode_show(struct device *dev,
136 				  struct device_attribute *attr, char *buf)
137 {
138 	const char *mode = lid_wake_mode_names[lid_wake_mode];
139 	return sprintf(buf, "%s\n", mode);
140 }
141 static ssize_t lid_wake_mode_set(struct device *dev,
142 				 struct device_attribute *attr,
143 				 const char *buf, size_t count)
144 {
145 	int i;
146 	for (i = 0; i < ARRAY_SIZE(lid_wake_mode_names); i++) {
147 		const char *mode = lid_wake_mode_names[i];
148 		if (strlen(mode) != count || strncasecmp(mode, buf, count))
149 			continue;
150 
151 		lid_wake_mode = i;
152 		return count;
153 	}
154 	return -EINVAL;
155 }
156 static DEVICE_ATTR(lid_wake_mode, S_IWUSR | S_IRUGO, lid_wake_mode_show,
157 		   lid_wake_mode_set);
158 
159 static struct attribute *lid_attrs[] = {
160 	&dev_attr_lid_wake_mode.attr,
161 	NULL,
162 };
163 ATTRIBUTE_GROUPS(lid);
164 
165 /*
166  * Process all items in the EC's SCI queue.
167  *
168  * This is handled in a workqueue because olpc_ec_cmd can be slow (and
169  * can even timeout).
170  *
171  * If propagate_events is false, the queue is drained without events being
172  * generated for the interrupts.
173  */
174 static void process_sci_queue(bool propagate_events)
175 {
176 	int r;
177 	u16 data;
178 
179 	do {
180 		r = olpc_ec_sci_query(&data);
181 		if (r || !data)
182 			break;
183 
184 		pr_debug(PFX "SCI 0x%x received\n", data);
185 
186 		switch (data) {
187 		case EC_SCI_SRC_BATERR:
188 		case EC_SCI_SRC_BATSOC:
189 		case EC_SCI_SRC_BATTERY:
190 		case EC_SCI_SRC_BATCRIT:
191 			battery_status_changed();
192 			break;
193 		case EC_SCI_SRC_ACPWR:
194 			ac_status_changed();
195 			break;
196 		}
197 
198 		if (data == EC_SCI_SRC_EBOOK && propagate_events)
199 			send_ebook_state();
200 	} while (data);
201 
202 	if (r)
203 		pr_err(PFX "Failed to clear SCI queue");
204 }
205 
206 static void process_sci_queue_work(struct work_struct *work)
207 {
208 	process_sci_queue(true);
209 }
210 
211 static DECLARE_WORK(sci_work, process_sci_queue_work);
212 
213 static irqreturn_t xo1_sci_intr(int irq, void *dev_id)
214 {
215 	struct platform_device *pdev = dev_id;
216 	u32 sts;
217 	u32 gpe;
218 
219 	sts = inl(acpi_base + CS5536_PM1_STS);
220 	outl(sts | 0xffff, acpi_base + CS5536_PM1_STS);
221 
222 	gpe = inl(acpi_base + CS5536_PM_GPE0_STS);
223 	outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
224 
225 	dev_dbg(&pdev->dev, "sts %x gpe %x\n", sts, gpe);
226 
227 	if (sts & CS5536_PWRBTN_FLAG) {
228 		if (!(sts & CS5536_WAK_FLAG)) {
229 			/* Only report power button input when it was pressed
230 			 * during regular operation (as opposed to when it
231 			 * was used to wake the system). */
232 			input_report_key(power_button_idev, KEY_POWER, 1);
233 			input_sync(power_button_idev);
234 			input_report_key(power_button_idev, KEY_POWER, 0);
235 			input_sync(power_button_idev);
236 		}
237 		/* Report the wakeup event in all cases. */
238 		pm_wakeup_event(&power_button_idev->dev, 0);
239 	}
240 
241 	if ((sts & (CS5536_RTC_FLAG | CS5536_WAK_FLAG)) ==
242 			(CS5536_RTC_FLAG | CS5536_WAK_FLAG)) {
243 		/* When the system is woken by the RTC alarm, report the
244 		 * event on the rtc device. */
245 		struct device *rtc = bus_find_device_by_name(
246 			&platform_bus_type, NULL, "rtc_cmos");
247 		if (rtc) {
248 			pm_wakeup_event(rtc, 0);
249 			put_device(rtc);
250 		}
251 	}
252 
253 	if (gpe & CS5536_GPIOM7_PME_FLAG) { /* EC GPIO */
254 		cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_NEGATIVE_EDGE_STS);
255 		schedule_work(&sci_work);
256 	}
257 
258 	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
259 	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
260 	detect_lid_state();
261 	send_lid_state();
262 
263 	return IRQ_HANDLED;
264 }
265 
266 static int xo1_sci_suspend(struct platform_device *pdev, pm_message_t state)
267 {
268 	if (device_may_wakeup(&power_button_idev->dev))
269 		olpc_xo1_pm_wakeup_set(CS5536_PM_PWRBTN);
270 	else
271 		olpc_xo1_pm_wakeup_clear(CS5536_PM_PWRBTN);
272 
273 	if (device_may_wakeup(&ebook_switch_idev->dev))
274 		olpc_ec_wakeup_set(EC_SCI_SRC_EBOOK);
275 	else
276 		olpc_ec_wakeup_clear(EC_SCI_SRC_EBOOK);
277 
278 	if (!device_may_wakeup(&lid_switch_idev->dev)) {
279 		cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
280 	} else if ((lid_open && lid_wake_mode == LID_WAKE_OPEN) ||
281 		   (!lid_open && lid_wake_mode == LID_WAKE_CLOSE)) {
282 		flip_lid_inverter();
283 
284 		/* we may have just caused an event */
285 		cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
286 		cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
287 
288 		cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
289 	}
290 
291 	return 0;
292 }
293 
294 static int xo1_sci_resume(struct platform_device *pdev)
295 {
296 	/*
297 	 * We don't know what may have happened while we were asleep.
298 	 * Reestablish our lid setup so we're sure to catch all transitions.
299 	 */
300 	detect_lid_state();
301 	send_lid_state();
302 	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
303 
304 	/* Enable all EC events */
305 	olpc_ec_mask_write(EC_SCI_SRC_ALL);
306 
307 	/* Power/battery status might have changed too */
308 	battery_status_changed();
309 	ac_status_changed();
310 	return 0;
311 }
312 
313 static int setup_sci_interrupt(struct platform_device *pdev)
314 {
315 	u32 lo, hi;
316 	u32 sts;
317 	int r;
318 
319 	rdmsr(0x51400020, lo, hi);
320 	sci_irq = (lo >> 20) & 15;
321 
322 	if (sci_irq) {
323 		dev_info(&pdev->dev, "SCI is mapped to IRQ %d\n", sci_irq);
324 	} else {
325 		/* Zero means masked */
326 		dev_info(&pdev->dev, "SCI unmapped. Mapping to IRQ 3\n");
327 		sci_irq = 3;
328 		lo |= 0x00300000;
329 		wrmsrl(0x51400020, lo);
330 	}
331 
332 	/* Select level triggered in PIC */
333 	if (sci_irq < 8) {
334 		lo = inb(CS5536_PIC_INT_SEL1);
335 		lo |= 1 << sci_irq;
336 		outb(lo, CS5536_PIC_INT_SEL1);
337 	} else {
338 		lo = inb(CS5536_PIC_INT_SEL2);
339 		lo |= 1 << (sci_irq - 8);
340 		outb(lo, CS5536_PIC_INT_SEL2);
341 	}
342 
343 	/* Enable interesting SCI events, and clear pending interrupts */
344 	sts = inl(acpi_base + CS5536_PM1_STS);
345 	outl(((CS5536_PM_PWRBTN | CS5536_PM_RTC) << 16) | 0xffff,
346 	     acpi_base + CS5536_PM1_STS);
347 
348 	r = request_irq(sci_irq, xo1_sci_intr, 0, DRV_NAME, pdev);
349 	if (r)
350 		dev_err(&pdev->dev, "can't request interrupt\n");
351 
352 	return r;
353 }
354 
355 static int setup_ec_sci(void)
356 {
357 	int r;
358 
359 	r = gpio_request(OLPC_GPIO_ECSCI, "OLPC-ECSCI");
360 	if (r)
361 		return r;
362 
363 	gpio_direction_input(OLPC_GPIO_ECSCI);
364 
365 	/* Clear pending EC SCI events */
366 	cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_NEGATIVE_EDGE_STS);
367 	cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_POSITIVE_EDGE_STS);
368 
369 	/*
370 	 * Enable EC SCI events, and map them to both a PME and the SCI
371 	 * interrupt.
372 	 *
373 	 * Ordinarily, in addition to functioning as GPIOs, Geode GPIOs can
374 	 * be mapped to regular interrupts *or* Geode-specific Power
375 	 * Management Events (PMEs) - events that bring the system out of
376 	 * suspend. In this case, we want both of those things - the system
377 	 * wakeup, *and* the ability to get an interrupt when an event occurs.
378 	 *
379 	 * To achieve this, we map the GPIO to a PME, and then we use one
380 	 * of the many generic knobs on the CS5535 PIC to additionally map the
381 	 * PME to the regular SCI interrupt line.
382 	 */
383 	cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_EVENTS_ENABLE);
384 
385 	/* Set the SCI to cause a PME event on group 7 */
386 	cs5535_gpio_setup_event(OLPC_GPIO_ECSCI, 7, 1);
387 
388 	/* And have group 7 also fire the SCI interrupt */
389 	cs5535_pic_unreqz_select_high(7, sci_irq);
390 
391 	return 0;
392 }
393 
394 static void free_ec_sci(void)
395 {
396 	gpio_free(OLPC_GPIO_ECSCI);
397 }
398 
399 static int setup_lid_events(void)
400 {
401 	int r;
402 
403 	r = gpio_request(OLPC_GPIO_LID, "OLPC-LID");
404 	if (r)
405 		return r;
406 
407 	gpio_direction_input(OLPC_GPIO_LID);
408 
409 	cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
410 	lid_inverted = 0;
411 
412 	/* Clear edge detection and event enable for now */
413 	cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
414 	cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_EN);
415 	cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_EN);
416 	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
417 	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
418 
419 	/* Set the LID to cause an PME event on group 6 */
420 	cs5535_gpio_setup_event(OLPC_GPIO_LID, 6, 1);
421 
422 	/* Set PME group 6 to fire the SCI interrupt */
423 	cs5535_gpio_set_irq(6, sci_irq);
424 
425 	/* Enable the event */
426 	cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
427 
428 	return 0;
429 }
430 
431 static void free_lid_events(void)
432 {
433 	gpio_free(OLPC_GPIO_LID);
434 }
435 
436 static int setup_power_button(struct platform_device *pdev)
437 {
438 	int r;
439 
440 	power_button_idev = input_allocate_device();
441 	if (!power_button_idev)
442 		return -ENOMEM;
443 
444 	power_button_idev->name = "Power Button";
445 	power_button_idev->phys = DRV_NAME "/input0";
446 	set_bit(EV_KEY, power_button_idev->evbit);
447 	set_bit(KEY_POWER, power_button_idev->keybit);
448 
449 	power_button_idev->dev.parent = &pdev->dev;
450 	device_init_wakeup(&power_button_idev->dev, 1);
451 
452 	r = input_register_device(power_button_idev);
453 	if (r) {
454 		dev_err(&pdev->dev, "failed to register power button: %d\n", r);
455 		input_free_device(power_button_idev);
456 	}
457 
458 	return r;
459 }
460 
461 static void free_power_button(void)
462 {
463 	input_unregister_device(power_button_idev);
464 }
465 
466 static int 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 }
495 
496 static int 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 	return 0;
519 
520 err_register:
521 	input_free_device(lid_switch_idev);
522 	return r;
523 }
524 
525 static void free_lid_switch(void)
526 {
527 	input_unregister_device(lid_switch_idev);
528 }
529 
530 static int xo1_sci_probe(struct platform_device *pdev)
531 {
532 	struct resource *res;
533 	int r;
534 
535 	/* don't run on non-XOs */
536 	if (!machine_is_olpc())
537 		return -ENODEV;
538 
539 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
540 	if (!res) {
541 		dev_err(&pdev->dev, "can't fetch device resource info\n");
542 		return -EIO;
543 	}
544 	acpi_base = res->start;
545 
546 	r = setup_power_button(pdev);
547 	if (r)
548 		return r;
549 
550 	r = setup_ebook_switch(pdev);
551 	if (r)
552 		goto err_ebook;
553 
554 	r = setup_lid_switch(pdev);
555 	if (r)
556 		goto err_lid;
557 
558 	r = setup_lid_events();
559 	if (r)
560 		goto err_lidevt;
561 
562 	r = setup_ec_sci();
563 	if (r)
564 		goto err_ecsci;
565 
566 	/* Enable PME generation for EC-generated events */
567 	outl(CS5536_GPIOM6_PME_EN | CS5536_GPIOM7_PME_EN,
568 		acpi_base + CS5536_PM_GPE0_EN);
569 
570 	/* Clear pending events */
571 	outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
572 	process_sci_queue(false);
573 
574 	/* Initial sync */
575 	send_ebook_state();
576 	detect_lid_state();
577 	send_lid_state();
578 
579 	r = setup_sci_interrupt(pdev);
580 	if (r)
581 		goto err_sci;
582 
583 	/* Enable all EC events */
584 	olpc_ec_mask_write(EC_SCI_SRC_ALL);
585 
586 	return r;
587 
588 err_sci:
589 	free_ec_sci();
590 err_ecsci:
591 	free_lid_events();
592 err_lidevt:
593 	free_lid_switch();
594 err_lid:
595 	free_ebook_switch();
596 err_ebook:
597 	free_power_button();
598 	return r;
599 }
600 
601 static int xo1_sci_remove(struct platform_device *pdev)
602 {
603 	free_irq(sci_irq, pdev);
604 	cancel_work_sync(&sci_work);
605 	free_ec_sci();
606 	free_lid_events();
607 	free_lid_switch();
608 	free_ebook_switch();
609 	free_power_button();
610 	acpi_base = 0;
611 	return 0;
612 }
613 
614 static struct platform_driver xo1_sci_driver = {
615 	.driver = {
616 		.name = "olpc-xo1-sci-acpi",
617 		.dev_groups = lid_groups,
618 	},
619 	.probe = xo1_sci_probe,
620 	.remove = xo1_sci_remove,
621 	.suspend = xo1_sci_suspend,
622 	.resume = xo1_sci_resume,
623 };
624 
625 static int __init xo1_sci_init(void)
626 {
627 	return platform_driver_register(&xo1_sci_driver);
628 }
629 arch_initcall(xo1_sci_init);
630