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/mfd/core.h>
19 #include <linux/power_supply.h>
20 #include <linux/suspend.h>
21 #include <linux/workqueue.h>
22 #include <linux/olpc-ec.h>
23
24 #include <asm/io.h>
25 #include <asm/msr.h>
26 #include <asm/olpc.h>
27
28 #define DRV_NAME "olpc-xo1-sci"
29 #define PFX DRV_NAME ": "
30
31 static unsigned long acpi_base;
32 static struct input_dev *power_button_idev;
33 static struct input_dev *ebook_switch_idev;
34 static struct input_dev *lid_switch_idev;
35
36 static int sci_irq;
37
38 static bool lid_open;
39 static bool lid_inverted;
40 static int lid_wake_mode;
41
42 enum lid_wake_modes {
43 LID_WAKE_ALWAYS,
44 LID_WAKE_OPEN,
45 LID_WAKE_CLOSE,
46 };
47
48 static const char * const lid_wake_mode_names[] = {
49 [LID_WAKE_ALWAYS] = "always",
50 [LID_WAKE_OPEN] = "open",
51 [LID_WAKE_CLOSE] = "close",
52 };
53
battery_status_changed(void)54 static void battery_status_changed(void)
55 {
56 struct power_supply *psy = power_supply_get_by_name("olpc-battery");
57
58 if (psy) {
59 power_supply_changed(psy);
60 power_supply_put(psy);
61 }
62 }
63
ac_status_changed(void)64 static void ac_status_changed(void)
65 {
66 struct power_supply *psy = power_supply_get_by_name("olpc-ac");
67
68 if (psy) {
69 power_supply_changed(psy);
70 power_supply_put(psy);
71 }
72 }
73
74 /* Report current ebook switch state through input layer */
send_ebook_state(void)75 static void send_ebook_state(void)
76 {
77 unsigned char state;
78
79 if (olpc_ec_cmd(EC_READ_EB_MODE, NULL, 0, &state, 1)) {
80 pr_err(PFX "failed to get ebook state\n");
81 return;
82 }
83
84 if (!!test_bit(SW_TABLET_MODE, ebook_switch_idev->sw) == state)
85 return; /* Nothing new to report. */
86
87 input_report_switch(ebook_switch_idev, SW_TABLET_MODE, state);
88 input_sync(ebook_switch_idev);
89 pm_wakeup_event(&ebook_switch_idev->dev, 0);
90 }
91
flip_lid_inverter(void)92 static void flip_lid_inverter(void)
93 {
94 /* gpio is high; invert so we'll get l->h event interrupt */
95 if (lid_inverted)
96 cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
97 else
98 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
99 lid_inverted = !lid_inverted;
100 }
101
detect_lid_state(void)102 static void detect_lid_state(void)
103 {
104 /*
105 * the edge detector hookup on the gpio inputs on the geode is
106 * odd, to say the least. See http://dev.laptop.org/ticket/5703
107 * for details, but in a nutshell: we don't use the edge
108 * detectors. instead, we make use of an anomaly: with the both
109 * edge detectors turned off, we still get an edge event on a
110 * positive edge transition. to take advantage of this, we use the
111 * front-end inverter to ensure that that's the edge we're always
112 * going to see next.
113 */
114
115 int state;
116
117 state = cs5535_gpio_isset(OLPC_GPIO_LID, GPIO_READ_BACK);
118 lid_open = !state ^ !lid_inverted; /* x ^^ y */
119 if (!state)
120 return;
121
122 flip_lid_inverter();
123 }
124
125 /* Report current lid switch state through input layer */
send_lid_state(void)126 static void send_lid_state(void)
127 {
128 if (!!test_bit(SW_LID, lid_switch_idev->sw) == !lid_open)
129 return; /* Nothing new to report. */
130
131 input_report_switch(lid_switch_idev, SW_LID, !lid_open);
132 input_sync(lid_switch_idev);
133 pm_wakeup_event(&lid_switch_idev->dev, 0);
134 }
135
lid_wake_mode_show(struct device * dev,struct device_attribute * attr,char * buf)136 static ssize_t lid_wake_mode_show(struct device *dev,
137 struct device_attribute *attr, char *buf)
138 {
139 const char *mode = lid_wake_mode_names[lid_wake_mode];
140 return sprintf(buf, "%s\n", mode);
141 }
lid_wake_mode_set(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)142 static ssize_t lid_wake_mode_set(struct device *dev,
143 struct device_attribute *attr,
144 const char *buf, size_t count)
145 {
146 int i;
147 for (i = 0; i < ARRAY_SIZE(lid_wake_mode_names); i++) {
148 const char *mode = lid_wake_mode_names[i];
149 if (strlen(mode) != count || strncasecmp(mode, buf, count))
150 continue;
151
152 lid_wake_mode = i;
153 return count;
154 }
155 return -EINVAL;
156 }
157 static DEVICE_ATTR(lid_wake_mode, S_IWUSR | S_IRUGO, lid_wake_mode_show,
158 lid_wake_mode_set);
159
160 static struct attribute *lid_attrs[] = {
161 &dev_attr_lid_wake_mode.attr,
162 NULL,
163 };
164 ATTRIBUTE_GROUPS(lid);
165
166 /*
167 * Process all items in the EC's SCI queue.
168 *
169 * This is handled in a workqueue because olpc_ec_cmd can be slow (and
170 * can even timeout).
171 *
172 * If propagate_events is false, the queue is drained without events being
173 * generated for the interrupts.
174 */
process_sci_queue(bool propagate_events)175 static void process_sci_queue(bool propagate_events)
176 {
177 int r;
178 u16 data;
179
180 do {
181 r = olpc_ec_sci_query(&data);
182 if (r || !data)
183 break;
184
185 pr_debug(PFX "SCI 0x%x received\n", data);
186
187 switch (data) {
188 case EC_SCI_SRC_BATERR:
189 case EC_SCI_SRC_BATSOC:
190 case EC_SCI_SRC_BATTERY:
191 case EC_SCI_SRC_BATCRIT:
192 battery_status_changed();
193 break;
194 case EC_SCI_SRC_ACPWR:
195 ac_status_changed();
196 break;
197 }
198
199 if (data == EC_SCI_SRC_EBOOK && propagate_events)
200 send_ebook_state();
201 } while (data);
202
203 if (r)
204 pr_err(PFX "Failed to clear SCI queue");
205 }
206
process_sci_queue_work(struct work_struct * work)207 static void process_sci_queue_work(struct work_struct *work)
208 {
209 process_sci_queue(true);
210 }
211
212 static DECLARE_WORK(sci_work, process_sci_queue_work);
213
xo1_sci_intr(int irq,void * dev_id)214 static irqreturn_t xo1_sci_intr(int irq, void *dev_id)
215 {
216 struct platform_device *pdev = dev_id;
217 u32 sts;
218 u32 gpe;
219
220 sts = inl(acpi_base + CS5536_PM1_STS);
221 outl(sts | 0xffff, acpi_base + CS5536_PM1_STS);
222
223 gpe = inl(acpi_base + CS5536_PM_GPE0_STS);
224 outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
225
226 dev_dbg(&pdev->dev, "sts %x gpe %x\n", sts, gpe);
227
228 if (sts & CS5536_PWRBTN_FLAG) {
229 if (!(sts & CS5536_WAK_FLAG)) {
230 /* Only report power button input when it was pressed
231 * during regular operation (as opposed to when it
232 * was used to wake the system). */
233 input_report_key(power_button_idev, KEY_POWER, 1);
234 input_sync(power_button_idev);
235 input_report_key(power_button_idev, KEY_POWER, 0);
236 input_sync(power_button_idev);
237 }
238 /* Report the wakeup event in all cases. */
239 pm_wakeup_event(&power_button_idev->dev, 0);
240 }
241
242 if ((sts & (CS5536_RTC_FLAG | CS5536_WAK_FLAG)) ==
243 (CS5536_RTC_FLAG | CS5536_WAK_FLAG)) {
244 /* When the system is woken by the RTC alarm, report the
245 * event on the rtc device. */
246 struct device *rtc = bus_find_device_by_name(
247 &platform_bus_type, NULL, "rtc_cmos");
248 if (rtc) {
249 pm_wakeup_event(rtc, 0);
250 put_device(rtc);
251 }
252 }
253
254 if (gpe & CS5536_GPIOM7_PME_FLAG) { /* EC GPIO */
255 cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_NEGATIVE_EDGE_STS);
256 schedule_work(&sci_work);
257 }
258
259 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
260 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
261 detect_lid_state();
262 send_lid_state();
263
264 return IRQ_HANDLED;
265 }
266
xo1_sci_suspend(struct platform_device * pdev,pm_message_t state)267 static int xo1_sci_suspend(struct platform_device *pdev, pm_message_t state)
268 {
269 if (device_may_wakeup(&power_button_idev->dev))
270 olpc_xo1_pm_wakeup_set(CS5536_PM_PWRBTN);
271 else
272 olpc_xo1_pm_wakeup_clear(CS5536_PM_PWRBTN);
273
274 if (device_may_wakeup(&ebook_switch_idev->dev))
275 olpc_ec_wakeup_set(EC_SCI_SRC_EBOOK);
276 else
277 olpc_ec_wakeup_clear(EC_SCI_SRC_EBOOK);
278
279 if (!device_may_wakeup(&lid_switch_idev->dev)) {
280 cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
281 } else if ((lid_open && lid_wake_mode == LID_WAKE_OPEN) ||
282 (!lid_open && lid_wake_mode == LID_WAKE_CLOSE)) {
283 flip_lid_inverter();
284
285 /* we may have just caused an event */
286 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
287 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
288
289 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
290 }
291
292 return 0;
293 }
294
xo1_sci_resume(struct platform_device * pdev)295 static int xo1_sci_resume(struct platform_device *pdev)
296 {
297 /*
298 * We don't know what may have happened while we were asleep.
299 * Reestablish our lid setup so we're sure to catch all transitions.
300 */
301 detect_lid_state();
302 send_lid_state();
303 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
304
305 /* Enable all EC events */
306 olpc_ec_mask_write(EC_SCI_SRC_ALL);
307
308 /* Power/battery status might have changed too */
309 battery_status_changed();
310 ac_status_changed();
311 return 0;
312 }
313
setup_sci_interrupt(struct platform_device * pdev)314 static int setup_sci_interrupt(struct platform_device *pdev)
315 {
316 u32 lo, hi;
317 u32 sts;
318 int r;
319
320 rdmsr(0x51400020, lo, hi);
321 sci_irq = (lo >> 20) & 15;
322
323 if (sci_irq) {
324 dev_info(&pdev->dev, "SCI is mapped to IRQ %d\n", sci_irq);
325 } else {
326 /* Zero means masked */
327 dev_info(&pdev->dev, "SCI unmapped. Mapping to IRQ 3\n");
328 sci_irq = 3;
329 lo |= 0x00300000;
330 wrmsrl(0x51400020, lo);
331 }
332
333 /* Select level triggered in PIC */
334 if (sci_irq < 8) {
335 lo = inb(CS5536_PIC_INT_SEL1);
336 lo |= 1 << sci_irq;
337 outb(lo, CS5536_PIC_INT_SEL1);
338 } else {
339 lo = inb(CS5536_PIC_INT_SEL2);
340 lo |= 1 << (sci_irq - 8);
341 outb(lo, CS5536_PIC_INT_SEL2);
342 }
343
344 /* Enable interesting SCI events, and clear pending interrupts */
345 sts = inl(acpi_base + CS5536_PM1_STS);
346 outl(((CS5536_PM_PWRBTN | CS5536_PM_RTC) << 16) | 0xffff,
347 acpi_base + CS5536_PM1_STS);
348
349 r = request_irq(sci_irq, xo1_sci_intr, 0, DRV_NAME, pdev);
350 if (r)
351 dev_err(&pdev->dev, "can't request interrupt\n");
352
353 return r;
354 }
355
setup_ec_sci(void)356 static int setup_ec_sci(void)
357 {
358 int r;
359
360 r = gpio_request(OLPC_GPIO_ECSCI, "OLPC-ECSCI");
361 if (r)
362 return r;
363
364 gpio_direction_input(OLPC_GPIO_ECSCI);
365
366 /* Clear pending EC SCI events */
367 cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_NEGATIVE_EDGE_STS);
368 cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_POSITIVE_EDGE_STS);
369
370 /*
371 * Enable EC SCI events, and map them to both a PME and the SCI
372 * interrupt.
373 *
374 * Ordinarily, in addition to functioning as GPIOs, Geode GPIOs can
375 * be mapped to regular interrupts *or* Geode-specific Power
376 * Management Events (PMEs) - events that bring the system out of
377 * suspend. In this case, we want both of those things - the system
378 * wakeup, *and* the ability to get an interrupt when an event occurs.
379 *
380 * To achieve this, we map the GPIO to a PME, and then we use one
381 * of the many generic knobs on the CS5535 PIC to additionally map the
382 * PME to the regular SCI interrupt line.
383 */
384 cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_EVENTS_ENABLE);
385
386 /* Set the SCI to cause a PME event on group 7 */
387 cs5535_gpio_setup_event(OLPC_GPIO_ECSCI, 7, 1);
388
389 /* And have group 7 also fire the SCI interrupt */
390 cs5535_pic_unreqz_select_high(7, sci_irq);
391
392 return 0;
393 }
394
free_ec_sci(void)395 static void free_ec_sci(void)
396 {
397 gpio_free(OLPC_GPIO_ECSCI);
398 }
399
setup_lid_events(void)400 static int setup_lid_events(void)
401 {
402 int r;
403
404 r = gpio_request(OLPC_GPIO_LID, "OLPC-LID");
405 if (r)
406 return r;
407
408 gpio_direction_input(OLPC_GPIO_LID);
409
410 cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
411 lid_inverted = 0;
412
413 /* Clear edge detection and event enable for now */
414 cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
415 cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_EN);
416 cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_EN);
417 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
418 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
419
420 /* Set the LID to cause an PME event on group 6 */
421 cs5535_gpio_setup_event(OLPC_GPIO_LID, 6, 1);
422
423 /* Set PME group 6 to fire the SCI interrupt */
424 cs5535_gpio_set_irq(6, sci_irq);
425
426 /* Enable the event */
427 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
428
429 return 0;
430 }
431
free_lid_events(void)432 static void free_lid_events(void)
433 {
434 gpio_free(OLPC_GPIO_LID);
435 }
436
setup_power_button(struct platform_device * pdev)437 static int setup_power_button(struct platform_device *pdev)
438 {
439 int r;
440
441 power_button_idev = input_allocate_device();
442 if (!power_button_idev)
443 return -ENOMEM;
444
445 power_button_idev->name = "Power Button";
446 power_button_idev->phys = DRV_NAME "/input0";
447 set_bit(EV_KEY, power_button_idev->evbit);
448 set_bit(KEY_POWER, power_button_idev->keybit);
449
450 power_button_idev->dev.parent = &pdev->dev;
451 device_init_wakeup(&power_button_idev->dev, 1);
452
453 r = input_register_device(power_button_idev);
454 if (r) {
455 dev_err(&pdev->dev, "failed to register power button: %d\n", r);
456 input_free_device(power_button_idev);
457 }
458
459 return r;
460 }
461
free_power_button(void)462 static void free_power_button(void)
463 {
464 input_unregister_device(power_button_idev);
465 }
466
setup_ebook_switch(struct platform_device * pdev)467 static int setup_ebook_switch(struct platform_device *pdev)
468 {
469 int r;
470
471 ebook_switch_idev = input_allocate_device();
472 if (!ebook_switch_idev)
473 return -ENOMEM;
474
475 ebook_switch_idev->name = "EBook Switch";
476 ebook_switch_idev->phys = DRV_NAME "/input1";
477 set_bit(EV_SW, ebook_switch_idev->evbit);
478 set_bit(SW_TABLET_MODE, ebook_switch_idev->swbit);
479
480 ebook_switch_idev->dev.parent = &pdev->dev;
481 device_set_wakeup_capable(&ebook_switch_idev->dev, true);
482
483 r = input_register_device(ebook_switch_idev);
484 if (r) {
485 dev_err(&pdev->dev, "failed to register ebook switch: %d\n", r);
486 input_free_device(ebook_switch_idev);
487 }
488
489 return r;
490 }
491
free_ebook_switch(void)492 static void free_ebook_switch(void)
493 {
494 input_unregister_device(ebook_switch_idev);
495 }
496
setup_lid_switch(struct platform_device * pdev)497 static int 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 return 0;
520
521 err_register:
522 input_free_device(lid_switch_idev);
523 return r;
524 }
525
free_lid_switch(void)526 static void free_lid_switch(void)
527 {
528 input_unregister_device(lid_switch_idev);
529 }
530
xo1_sci_probe(struct platform_device * pdev)531 static int xo1_sci_probe(struct platform_device *pdev)
532 {
533 struct resource *res;
534 int r;
535
536 /* don't run on non-XOs */
537 if (!machine_is_olpc())
538 return -ENODEV;
539
540 r = mfd_cell_enable(pdev);
541 if (r)
542 return r;
543
544 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
545 if (!res) {
546 dev_err(&pdev->dev, "can't fetch device resource info\n");
547 return -EIO;
548 }
549 acpi_base = res->start;
550
551 r = setup_power_button(pdev);
552 if (r)
553 return r;
554
555 r = setup_ebook_switch(pdev);
556 if (r)
557 goto err_ebook;
558
559 r = setup_lid_switch(pdev);
560 if (r)
561 goto err_lid;
562
563 r = setup_lid_events();
564 if (r)
565 goto err_lidevt;
566
567 r = setup_ec_sci();
568 if (r)
569 goto err_ecsci;
570
571 /* Enable PME generation for EC-generated events */
572 outl(CS5536_GPIOM6_PME_EN | CS5536_GPIOM7_PME_EN,
573 acpi_base + CS5536_PM_GPE0_EN);
574
575 /* Clear pending events */
576 outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
577 process_sci_queue(false);
578
579 /* Initial sync */
580 send_ebook_state();
581 detect_lid_state();
582 send_lid_state();
583
584 r = setup_sci_interrupt(pdev);
585 if (r)
586 goto err_sci;
587
588 /* Enable all EC events */
589 olpc_ec_mask_write(EC_SCI_SRC_ALL);
590
591 return r;
592
593 err_sci:
594 free_ec_sci();
595 err_ecsci:
596 free_lid_events();
597 err_lidevt:
598 free_lid_switch();
599 err_lid:
600 free_ebook_switch();
601 err_ebook:
602 free_power_button();
603 return r;
604 }
605
xo1_sci_remove(struct platform_device * pdev)606 static int xo1_sci_remove(struct platform_device *pdev)
607 {
608 mfd_cell_disable(pdev);
609 free_irq(sci_irq, pdev);
610 cancel_work_sync(&sci_work);
611 free_ec_sci();
612 free_lid_events();
613 free_lid_switch();
614 free_ebook_switch();
615 free_power_button();
616 acpi_base = 0;
617 return 0;
618 }
619
620 static struct platform_driver xo1_sci_driver = {
621 .driver = {
622 .name = "olpc-xo1-sci-acpi",
623 .dev_groups = lid_groups,
624 },
625 .probe = xo1_sci_probe,
626 .remove = xo1_sci_remove,
627 .suspend = xo1_sci_suspend,
628 .resume = xo1_sci_resume,
629 };
630
xo1_sci_init(void)631 static int __init xo1_sci_init(void)
632 {
633 return platform_driver_register(&xo1_sci_driver);
634 }
635 arch_initcall(xo1_sci_init);
636
