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/power_supply.h>
18 #include <linux/suspend.h>
19 #include <linux/workqueue.h>
20 #include <linux/olpc-ec.h>
21 
22 #include <asm/io.h>
23 #include <asm/msr.h>
24 #include <asm/olpc.h>
25 
26 #define DRV_NAME	"olpc-xo1-sci"
27 #define PFX		DRV_NAME ": "
28 
29 static unsigned long acpi_base;
30 static struct input_dev *power_button_idev;
31 static struct input_dev *ebook_switch_idev;
32 static struct input_dev *lid_switch_idev;
33 
34 static int sci_irq;
35 
36 static bool lid_open;
37 static bool lid_inverted;
38 static int lid_wake_mode;
39 
40 enum lid_wake_modes {
41 	LID_WAKE_ALWAYS,
42 	LID_WAKE_OPEN,
43 	LID_WAKE_CLOSE,
44 };
45 
46 static const char * const lid_wake_mode_names[] = {
47 	[LID_WAKE_ALWAYS] = "always",
48 	[LID_WAKE_OPEN] = "open",
49 	[LID_WAKE_CLOSE] = "close",
50 };
51 
battery_status_changed(void)52 static void battery_status_changed(void)
53 {
54 	struct power_supply *psy = power_supply_get_by_name("olpc_battery");
55 
56 	if (psy) {
57 		power_supply_changed(psy);
58 		power_supply_put(psy);
59 	}
60 }
61 
ac_status_changed(void)62 static void ac_status_changed(void)
63 {
64 	struct power_supply *psy = power_supply_get_by_name("olpc_ac");
65 
66 	if (psy) {
67 		power_supply_changed(psy);
68 		power_supply_put(psy);
69 	}
70 }
71 
72 /* Report current ebook switch state through input layer */
send_ebook_state(void)73 static void send_ebook_state(void)
74 {
75 	unsigned char state;
76 
77 	if (olpc_ec_cmd(EC_READ_EB_MODE, NULL, 0, &state, 1)) {
78 		pr_err(PFX "failed to get ebook state\n");
79 		return;
80 	}
81 
82 	if (test_bit(SW_TABLET_MODE, ebook_switch_idev->sw) == !!state)
83 		return; /* Nothing new to report. */
84 
85 	input_report_switch(ebook_switch_idev, SW_TABLET_MODE, state);
86 	input_sync(ebook_switch_idev);
87 	pm_wakeup_event(&ebook_switch_idev->dev, 0);
88 }
89 
flip_lid_inverter(void)90 static void flip_lid_inverter(void)
91 {
92 	/* gpio is high; invert so we'll get l->h event interrupt */
93 	if (lid_inverted)
94 		cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
95 	else
96 		cs5535_gpio_set(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
97 	lid_inverted = !lid_inverted;
98 }
99 
detect_lid_state(void)100 static void detect_lid_state(void)
101 {
102 	/*
103 	 * the edge detector hookup on the gpio inputs on the geode is
104 	 * odd, to say the least.  See http://dev.laptop.org/ticket/5703
105 	 * for details, but in a nutshell:  we don't use the edge
106 	 * detectors.  instead, we make use of an anomaly:  with the both
107 	 * edge detectors turned off, we still get an edge event on a
108 	 * positive edge transition.  to take advantage of this, we use the
109 	 * front-end inverter to ensure that that's the edge we're always
110 	 * going to see next.
111 	 */
112 
113 	int state;
114 
115 	state = cs5535_gpio_isset(OLPC_GPIO_LID, GPIO_READ_BACK);
116 	lid_open = !state ^ !lid_inverted; /* x ^^ y */
117 	if (!state)
118 		return;
119 
120 	flip_lid_inverter();
121 }
122 
123 /* Report current lid switch state through input layer */
send_lid_state(void)124 static void send_lid_state(void)
125 {
126 	if (!!test_bit(SW_LID, lid_switch_idev->sw) == !lid_open)
127 		return; /* Nothing new to report. */
128 
129 	input_report_switch(lid_switch_idev, SW_LID, !lid_open);
130 	input_sync(lid_switch_idev);
131 	pm_wakeup_event(&lid_switch_idev->dev, 0);
132 }
133 
lid_wake_mode_show(struct device * dev,struct device_attribute * attr,char * buf)134 static ssize_t lid_wake_mode_show(struct device *dev,
135 				  struct device_attribute *attr, char *buf)
136 {
137 	const char *mode = lid_wake_mode_names[lid_wake_mode];
138 	return sprintf(buf, "%s\n", mode);
139 }
lid_wake_mode_set(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)140 static ssize_t lid_wake_mode_set(struct device *dev,
141 				 struct device_attribute *attr,
142 				 const char *buf, size_t count)
143 {
144 	int i;
145 	for (i = 0; i < ARRAY_SIZE(lid_wake_mode_names); i++) {
146 		const char *mode = lid_wake_mode_names[i];
147 		if (strlen(mode) != count || strncasecmp(mode, buf, count))
148 			continue;
149 
150 		lid_wake_mode = i;
151 		return count;
152 	}
153 	return -EINVAL;
154 }
155 static DEVICE_ATTR(lid_wake_mode, S_IWUSR | S_IRUGO, lid_wake_mode_show,
156 		   lid_wake_mode_set);
157 
158 static struct attribute *lid_attrs[] = {
159 	&dev_attr_lid_wake_mode.attr,
160 	NULL,
161 };
162 ATTRIBUTE_GROUPS(lid);
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  */
process_sci_queue(bool propagate_events)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 
process_sci_queue_work(struct work_struct * work)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 
xo1_sci_intr(int irq,void * dev_id)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 
xo1_sci_suspend(struct platform_device * pdev,pm_message_t state)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 
xo1_sci_resume(struct platform_device * pdev)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 
setup_sci_interrupt(struct platform_device * pdev)312 static 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 
setup_ec_sci(void)354 static 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 
free_ec_sci(void)393 static void free_ec_sci(void)
394 {
395 	gpio_free(OLPC_GPIO_ECSCI);
396 }
397 
setup_lid_events(void)398 static 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 
free_lid_events(void)430 static void free_lid_events(void)
431 {
432 	gpio_free(OLPC_GPIO_LID);
433 }
434 
setup_power_button(struct platform_device * pdev)435 static 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 
free_power_button(void)460 static void free_power_button(void)
461 {
462 	input_unregister_device(power_button_idev);
463 }
464 
setup_ebook_switch(struct platform_device * pdev)465 static 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 
free_ebook_switch(void)490 static void free_ebook_switch(void)
491 {
492 	input_unregister_device(ebook_switch_idev);
493 }
494 
setup_lid_switch(struct platform_device * pdev)495 static 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 	return 0;
518 
519 err_register:
520 	input_free_device(lid_switch_idev);
521 	return r;
522 }
523 
free_lid_switch(void)524 static void free_lid_switch(void)
525 {
526 	input_unregister_device(lid_switch_idev);
527 }
528 
xo1_sci_probe(struct platform_device * pdev)529 static int xo1_sci_probe(struct platform_device *pdev)
530 {
531 	struct resource *res;
532 	int r;
533 
534 	/* don't run on non-XOs */
535 	if (!machine_is_olpc())
536 		return -ENODEV;
537 
538 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
539 	if (!res) {
540 		dev_err(&pdev->dev, "can't fetch device resource info\n");
541 		return -EIO;
542 	}
543 	acpi_base = res->start;
544 
545 	r = setup_power_button(pdev);
546 	if (r)
547 		return r;
548 
549 	r = setup_ebook_switch(pdev);
550 	if (r)
551 		goto err_ebook;
552 
553 	r = setup_lid_switch(pdev);
554 	if (r)
555 		goto err_lid;
556 
557 	r = setup_lid_events();
558 	if (r)
559 		goto err_lidevt;
560 
561 	r = setup_ec_sci();
562 	if (r)
563 		goto err_ecsci;
564 
565 	/* Enable PME generation for EC-generated events */
566 	outl(CS5536_GPIOM6_PME_EN | CS5536_GPIOM7_PME_EN,
567 		acpi_base + CS5536_PM_GPE0_EN);
568 
569 	/* Clear pending events */
570 	outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
571 	process_sci_queue(false);
572 
573 	/* Initial sync */
574 	send_ebook_state();
575 	detect_lid_state();
576 	send_lid_state();
577 
578 	r = setup_sci_interrupt(pdev);
579 	if (r)
580 		goto err_sci;
581 
582 	/* Enable all EC events */
583 	olpc_ec_mask_write(EC_SCI_SRC_ALL);
584 
585 	return r;
586 
587 err_sci:
588 	free_ec_sci();
589 err_ecsci:
590 	free_lid_events();
591 err_lidevt:
592 	free_lid_switch();
593 err_lid:
594 	free_ebook_switch();
595 err_ebook:
596 	free_power_button();
597 	return r;
598 }
599 
xo1_sci_remove(struct platform_device * pdev)600 static void xo1_sci_remove(struct platform_device *pdev)
601 {
602 	free_irq(sci_irq, pdev);
603 	cancel_work_sync(&sci_work);
604 	free_ec_sci();
605 	free_lid_events();
606 	free_lid_switch();
607 	free_ebook_switch();
608 	free_power_button();
609 	acpi_base = 0;
610 }
611 
612 static struct platform_driver xo1_sci_driver = {
613 	.driver = {
614 		.name = "olpc-xo1-sci-acpi",
615 		.dev_groups = lid_groups,
616 	},
617 	.probe = xo1_sci_probe,
618 	.remove = xo1_sci_remove,
619 	.suspend = xo1_sci_suspend,
620 	.resume = xo1_sci_resume,
621 };
622 
xo1_sci_init(void)623 static int __init xo1_sci_init(void)
624 {
625 	return platform_driver_register(&xo1_sci_driver);
626 }
627 arch_initcall(xo1_sci_init);
628