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 void 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 }
612
613 static struct platform_driver xo1_sci_driver = {
614 .driver = {
615 .name = "olpc-xo1-sci-acpi",
616 .dev_groups = lid_groups,
617 },
618 .probe = xo1_sci_probe,
619 .remove_new = xo1_sci_remove,
620 .suspend = xo1_sci_suspend,
621 .resume = xo1_sci_resume,
622 };
623
624 static int __init xo1_sci_init(void)
625 {
626 return platform_driver_register(&xo1_sci_driver);
627 }
628 arch_initcall(xo1_sci_init);
629
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