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