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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Driver for the Surface ACPI Notify (SAN) interface/shim.
4 *
5 * Translates communication from ACPI to Surface System Aggregator Module
6 * (SSAM/SAM) requests and back, specifically SAM-over-SSH. Translates SSAM
7 * events back to ACPI notifications. Allows handling of discrete GPU
8 * notifications sent from ACPI via the SAN interface by providing them to any
9 * registered external driver.
10 *
11 * Copyright (C) 2019-2022 Maximilian Luz <luzmaximilian@gmail.com>
12 */
13
14#include <asm/unaligned.h>
15#include <linux/acpi.h>
16#include <linux/delay.h>
17#include <linux/jiffies.h>
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/notifier.h>
21#include <linux/platform_device.h>
22#include <linux/rwsem.h>
23
24#include <linux/surface_aggregator/controller.h>
25#include <linux/surface_acpi_notify.h>
26
27struct san_data {
28 struct device *dev;
29 struct ssam_controller *ctrl;
30
31 struct acpi_connection_info info;
32
33 struct ssam_event_notifier nf_bat;
34 struct ssam_event_notifier nf_tmp;
35};
36
37#define to_san_data(ptr, member) \
38 container_of(ptr, struct san_data, member)
39
40static struct workqueue_struct *san_wq;
41
42/* -- dGPU notifier interface. ---------------------------------------------- */
43
44struct san_rqsg_if {
45 struct rw_semaphore lock;
46 struct device *dev;
47 struct blocking_notifier_head nh;
48};
49
50static struct san_rqsg_if san_rqsg_if = {
51 .lock = __RWSEM_INITIALIZER(san_rqsg_if.lock),
52 .dev = NULL,
53 .nh = BLOCKING_NOTIFIER_INIT(san_rqsg_if.nh),
54};
55
56static int san_set_rqsg_interface_device(struct device *dev)
57{
58 int status = 0;
59
60 down_write(&san_rqsg_if.lock);
61 if (!san_rqsg_if.dev && dev)
62 san_rqsg_if.dev = dev;
63 else
64 status = -EBUSY;
65 up_write(&san_rqsg_if.lock);
66
67 return status;
68}
69
70/**
71 * san_client_link() - Link client as consumer to SAN device.
72 * @client: The client to link.
73 *
74 * Sets up a device link between the provided client device as consumer and
75 * the SAN device as provider. This function can be used to ensure that the
76 * SAN interface has been set up and will be set up for as long as the driver
77 * of the client device is bound. This guarantees that, during that time, all
78 * dGPU events will be received by any registered notifier.
79 *
80 * The link will be automatically removed once the client device's driver is
81 * unbound.
82 *
83 * Return: Returns zero on success, %-ENXIO if the SAN interface has not been
84 * set up yet, and %-ENOMEM if device link creation failed.
85 */
86int san_client_link(struct device *client)
87{
88 const u32 flags = DL_FLAG_PM_RUNTIME | DL_FLAG_AUTOREMOVE_CONSUMER;
89 struct device_link *link;
90
91 down_read(&san_rqsg_if.lock);
92
93 if (!san_rqsg_if.dev) {
94 up_read(&san_rqsg_if.lock);
95 return -ENXIO;
96 }
97
98 link = device_link_add(client, san_rqsg_if.dev, flags);
99 if (!link) {
100 up_read(&san_rqsg_if.lock);
101 return -ENOMEM;
102 }
103
104 if (READ_ONCE(link->status) == DL_STATE_SUPPLIER_UNBIND) {
105 up_read(&san_rqsg_if.lock);
106 return -ENXIO;
107 }
108
109 up_read(&san_rqsg_if.lock);
110 return 0;
111}
112EXPORT_SYMBOL_GPL(san_client_link);
113
114/**
115 * san_dgpu_notifier_register() - Register a SAN dGPU notifier.
116 * @nb: The notifier-block to register.
117 *
118 * Registers a SAN dGPU notifier, receiving any new SAN dGPU events sent from
119 * ACPI. The registered notifier will be called with &struct san_dgpu_event
120 * as notifier data and the command ID of that event as notifier action.
121 */
122int san_dgpu_notifier_register(struct notifier_block *nb)
123{
124 return blocking_notifier_chain_register(&san_rqsg_if.nh, nb);
125}
126EXPORT_SYMBOL_GPL(san_dgpu_notifier_register);
127
128/**
129 * san_dgpu_notifier_unregister() - Unregister a SAN dGPU notifier.
130 * @nb: The notifier-block to unregister.
131 */
132int san_dgpu_notifier_unregister(struct notifier_block *nb)
133{
134 return blocking_notifier_chain_unregister(&san_rqsg_if.nh, nb);
135}
136EXPORT_SYMBOL_GPL(san_dgpu_notifier_unregister);
137
138static int san_dgpu_notifier_call(struct san_dgpu_event *evt)
139{
140 int ret;
141
142 ret = blocking_notifier_call_chain(&san_rqsg_if.nh, evt->command, evt);
143 return notifier_to_errno(ret);
144}
145
146
147/* -- ACPI _DSM event relay. ------------------------------------------------ */
148
149#define SAN_DSM_REVISION 0
150
151/* 93b666c5-70c6-469f-a215-3d487c91ab3c */
152static const guid_t SAN_DSM_UUID =
153 GUID_INIT(0x93b666c5, 0x70c6, 0x469f, 0xa2, 0x15, 0x3d,
154 0x48, 0x7c, 0x91, 0xab, 0x3c);
155
156enum san_dsm_event_fn {
157 SAN_DSM_EVENT_FN_BAT1_STAT = 0x03,
158 SAN_DSM_EVENT_FN_BAT1_INFO = 0x04,
159 SAN_DSM_EVENT_FN_ADP1_STAT = 0x05,
160 SAN_DSM_EVENT_FN_ADP1_INFO = 0x06,
161 SAN_DSM_EVENT_FN_BAT2_STAT = 0x07,
162 SAN_DSM_EVENT_FN_BAT2_INFO = 0x08,
163 SAN_DSM_EVENT_FN_THERMAL = 0x09,
164 SAN_DSM_EVENT_FN_DPTF = 0x0a,
165};
166
167enum sam_event_cid_bat {
168 SAM_EVENT_CID_BAT_BIX = 0x15,
169 SAM_EVENT_CID_BAT_BST = 0x16,
170 SAM_EVENT_CID_BAT_ADP = 0x17,
171 SAM_EVENT_CID_BAT_PROT = 0x18,
172 SAM_EVENT_CID_BAT_DPTF = 0x4f,
173};
174
175enum sam_event_cid_tmp {
176 SAM_EVENT_CID_TMP_TRIP = 0x0b,
177};
178
179struct san_event_work {
180 struct delayed_work work;
181 struct device *dev;
182 struct ssam_event event; /* must be last */
183};
184
185static int san_acpi_notify_event(struct device *dev, u64 func,
186 union acpi_object *param)
187{
188 acpi_handle san = ACPI_HANDLE(dev);
189 union acpi_object *obj;
190 int status = 0;
191
192 if (!acpi_check_dsm(san, &SAN_DSM_UUID, SAN_DSM_REVISION, BIT_ULL(func)))
193 return 0;
194
195 dev_dbg(dev, "notify event %#04llx\n", func);
196
197 obj = acpi_evaluate_dsm_typed(san, &SAN_DSM_UUID, SAN_DSM_REVISION,
198 func, param, ACPI_TYPE_BUFFER);
199 if (!obj)
200 return -EFAULT;
201
202 if (obj->buffer.length != 1 || obj->buffer.pointer[0] != 0) {
203 dev_err(dev, "got unexpected result from _DSM\n");
204 status = -EPROTO;
205 }
206
207 ACPI_FREE(obj);
208 return status;
209}
210
211static int san_evt_bat_adp(struct device *dev, const struct ssam_event *event)
212{
213 int status;
214
215 status = san_acpi_notify_event(dev, SAN_DSM_EVENT_FN_ADP1_STAT, NULL);
216 if (status)
217 return status;
218
219 /*
220 * Ensure that the battery states get updated correctly. When the
221 * battery is fully charged and an adapter is plugged in, it sometimes
222 * is not updated correctly, instead showing it as charging.
223 * Explicitly trigger battery updates to fix this.
224 */
225
226 status = san_acpi_notify_event(dev, SAN_DSM_EVENT_FN_BAT1_STAT, NULL);
227 if (status)
228 return status;
229
230 return san_acpi_notify_event(dev, SAN_DSM_EVENT_FN_BAT2_STAT, NULL);
231}
232
233static int san_evt_bat_bix(struct device *dev, const struct ssam_event *event)
234{
235 enum san_dsm_event_fn fn;
236
237 if (event->instance_id == 0x02)
238 fn = SAN_DSM_EVENT_FN_BAT2_INFO;
239 else
240 fn = SAN_DSM_EVENT_FN_BAT1_INFO;
241
242 return san_acpi_notify_event(dev, fn, NULL);
243}
244
245static int san_evt_bat_bst(struct device *dev, const struct ssam_event *event)
246{
247 enum san_dsm_event_fn fn;
248
249 if (event->instance_id == 0x02)
250 fn = SAN_DSM_EVENT_FN_BAT2_STAT;
251 else
252 fn = SAN_DSM_EVENT_FN_BAT1_STAT;
253
254 return san_acpi_notify_event(dev, fn, NULL);
255}
256
257static int san_evt_bat_dptf(struct device *dev, const struct ssam_event *event)
258{
259 union acpi_object payload;
260
261 /*
262 * The Surface ACPI expects a buffer and not a package. It specifically
263 * checks for ObjectType (Arg3) == 0x03. This will cause a warning in
264 * acpica/nsarguments.c, but that warning can be safely ignored.
265 */
266 payload.type = ACPI_TYPE_BUFFER;
267 payload.buffer.length = event->length;
268 payload.buffer.pointer = (u8 *)&event->data[0];
269
270 return san_acpi_notify_event(dev, SAN_DSM_EVENT_FN_DPTF, &payload);
271}
272
273static unsigned long san_evt_bat_delay(u8 cid)
274{
275 switch (cid) {
276 case SAM_EVENT_CID_BAT_ADP:
277 /*
278 * Wait for battery state to update before signaling adapter
279 * change.
280 */
281 return msecs_to_jiffies(5000);
282
283 case SAM_EVENT_CID_BAT_BST:
284 /* Ensure we do not miss anything important due to caching. */
285 return msecs_to_jiffies(2000);
286
287 default:
288 return 0;
289 }
290}
291
292static bool san_evt_bat(const struct ssam_event *event, struct device *dev)
293{
294 int status;
295
296 switch (event->command_id) {
297 case SAM_EVENT_CID_BAT_BIX:
298 status = san_evt_bat_bix(dev, event);
299 break;
300
301 case SAM_EVENT_CID_BAT_BST:
302 status = san_evt_bat_bst(dev, event);
303 break;
304
305 case SAM_EVENT_CID_BAT_ADP:
306 status = san_evt_bat_adp(dev, event);
307 break;
308
309 case SAM_EVENT_CID_BAT_PROT:
310 /*
311 * TODO: Implement support for battery protection status change
312 * event.
313 */
314 return true;
315
316 case SAM_EVENT_CID_BAT_DPTF:
317 status = san_evt_bat_dptf(dev, event);
318 break;
319
320 default:
321 return false;
322 }
323
324 if (status) {
325 dev_err(dev, "error handling power event (cid = %#04x)\n",
326 event->command_id);
327 }
328
329 return true;
330}
331
332static void san_evt_bat_workfn(struct work_struct *work)
333{
334 struct san_event_work *ev;
335
336 ev = container_of(work, struct san_event_work, work.work);
337 san_evt_bat(&ev->event, ev->dev);
338 kfree(ev);
339}
340
341static u32 san_evt_bat_nf(struct ssam_event_notifier *nf,
342 const struct ssam_event *event)
343{
344 struct san_data *d = to_san_data(nf, nf_bat);
345 struct san_event_work *work;
346 unsigned long delay = san_evt_bat_delay(event->command_id);
347
348 if (delay == 0)
349 return san_evt_bat(event, d->dev) ? SSAM_NOTIF_HANDLED : 0;
350
351 work = kzalloc(sizeof(*work) + event->length, GFP_KERNEL);
352 if (!work)
353 return ssam_notifier_from_errno(-ENOMEM);
354
355 INIT_DELAYED_WORK(&work->work, san_evt_bat_workfn);
356 work->dev = d->dev;
357
358 work->event = *event;
359 memcpy(work->event.data, event->data, event->length);
360
361 queue_delayed_work(san_wq, &work->work, delay);
362 return SSAM_NOTIF_HANDLED;
363}
364
365static int san_evt_tmp_trip(struct device *dev, const struct ssam_event *event)
366{
367 union acpi_object param;
368
369 /*
370 * The Surface ACPI expects an integer and not a package. This will
371 * cause a warning in acpica/nsarguments.c, but that warning can be
372 * safely ignored.
373 */
374 param.type = ACPI_TYPE_INTEGER;
375 param.integer.value = event->instance_id;
376
377 return san_acpi_notify_event(dev, SAN_DSM_EVENT_FN_THERMAL, ¶m);
378}
379
380static bool san_evt_tmp(const struct ssam_event *event, struct device *dev)
381{
382 int status;
383
384 switch (event->command_id) {
385 case SAM_EVENT_CID_TMP_TRIP:
386 status = san_evt_tmp_trip(dev, event);
387 break;
388
389 default:
390 return false;
391 }
392
393 if (status) {
394 dev_err(dev, "error handling thermal event (cid = %#04x)\n",
395 event->command_id);
396 }
397
398 return true;
399}
400
401static u32 san_evt_tmp_nf(struct ssam_event_notifier *nf,
402 const struct ssam_event *event)
403{
404 struct san_data *d = to_san_data(nf, nf_tmp);
405
406 return san_evt_tmp(event, d->dev) ? SSAM_NOTIF_HANDLED : 0;
407}
408
409
410/* -- ACPI GSB OperationRegion handler -------------------------------------- */
411
412struct gsb_data_in {
413 u8 cv;
414} __packed;
415
416struct gsb_data_rqsx {
417 u8 cv; /* Command value (san_gsb_request_cv). */
418 u8 tc; /* Target category. */
419 u8 tid; /* Target ID. */
420 u8 iid; /* Instance ID. */
421 u8 snc; /* Expect-response-flag. */
422 u8 cid; /* Command ID. */
423 u16 cdl; /* Payload length. */
424 u8 pld[]; /* Payload. */
425} __packed;
426
427struct gsb_data_etwl {
428 u8 cv; /* Command value (should be 0x02). */
429 u8 etw3; /* Unknown. */
430 u8 etw4; /* Unknown. */
431 u8 msg[]; /* Error message (ASCIIZ). */
432} __packed;
433
434struct gsb_data_out {
435 u8 status; /* _SSH communication status. */
436 u8 len; /* _SSH payload length. */
437 u8 pld[]; /* _SSH payload. */
438} __packed;
439
440union gsb_buffer_data {
441 struct gsb_data_in in; /* Common input. */
442 struct gsb_data_rqsx rqsx; /* RQSX input. */
443 struct gsb_data_etwl etwl; /* ETWL input. */
444 struct gsb_data_out out; /* Output. */
445};
446
447struct gsb_buffer {
448 u8 status; /* GSB AttribRawProcess status. */
449 u8 len; /* GSB AttribRawProcess length. */
450 union gsb_buffer_data data;
451} __packed;
452
453#define SAN_GSB_MAX_RQSX_PAYLOAD (U8_MAX - 2 - sizeof(struct gsb_data_rqsx))
454#define SAN_GSB_MAX_RESPONSE (U8_MAX - 2 - sizeof(struct gsb_data_out))
455
456#define SAN_GSB_COMMAND 0
457
458enum san_gsb_request_cv {
459 SAN_GSB_REQUEST_CV_RQST = 0x01,
460 SAN_GSB_REQUEST_CV_ETWL = 0x02,
461 SAN_GSB_REQUEST_CV_RQSG = 0x03,
462};
463
464#define SAN_REQUEST_NUM_TRIES 5
465
466static acpi_status san_etwl(struct san_data *d, struct gsb_buffer *b)
467{
468 struct gsb_data_etwl *etwl = &b->data.etwl;
469
470 if (b->len < sizeof(struct gsb_data_etwl)) {
471 dev_err(d->dev, "invalid ETWL package (len = %d)\n", b->len);
472 return AE_OK;
473 }
474
475 dev_err(d->dev, "ETWL(%#04x, %#04x): %.*s\n", etwl->etw3, etwl->etw4,
476 (unsigned int)(b->len - sizeof(struct gsb_data_etwl)),
477 (char *)etwl->msg);
478
479 /* Indicate success. */
480 b->status = 0x00;
481 b->len = 0x00;
482
483 return AE_OK;
484}
485
486static
487struct gsb_data_rqsx *san_validate_rqsx(struct device *dev, const char *type,
488 struct gsb_buffer *b)
489{
490 struct gsb_data_rqsx *rqsx = &b->data.rqsx;
491
492 if (b->len < sizeof(struct gsb_data_rqsx)) {
493 dev_err(dev, "invalid %s package (len = %d)\n", type, b->len);
494 return NULL;
495 }
496
497 if (get_unaligned(&rqsx->cdl) != b->len - sizeof(struct gsb_data_rqsx)) {
498 dev_err(dev, "bogus %s package (len = %d, cdl = %d)\n",
499 type, b->len, get_unaligned(&rqsx->cdl));
500 return NULL;
501 }
502
503 if (get_unaligned(&rqsx->cdl) > SAN_GSB_MAX_RQSX_PAYLOAD) {
504 dev_err(dev, "payload for %s package too large (cdl = %d)\n",
505 type, get_unaligned(&rqsx->cdl));
506 return NULL;
507 }
508
509 return rqsx;
510}
511
512static void gsb_rqsx_response_error(struct gsb_buffer *gsb, int status)
513{
514 gsb->status = 0x00;
515 gsb->len = 0x02;
516 gsb->data.out.status = (u8)(-status);
517 gsb->data.out.len = 0x00;
518}
519
520static void gsb_rqsx_response_success(struct gsb_buffer *gsb, u8 *ptr, size_t len)
521{
522 gsb->status = 0x00;
523 gsb->len = len + 2;
524 gsb->data.out.status = 0x00;
525 gsb->data.out.len = len;
526
527 if (len)
528 memcpy(&gsb->data.out.pld[0], ptr, len);
529}
530
531static acpi_status san_rqst_fixup_suspended(struct san_data *d,
532 struct ssam_request *rqst,
533 struct gsb_buffer *gsb)
534{
535 if (rqst->target_category == SSAM_SSH_TC_BAS && rqst->command_id == 0x0D) {
536 u8 base_state = 1;
537
538 /* Base state quirk:
539 * The base state may be queried from ACPI when the EC is still
540 * suspended. In this case it will return '-EPERM'. This query
541 * will only be triggered from the ACPI lid GPE interrupt, thus
542 * we are either in laptop or studio mode (base status 0x01 or
543 * 0x02). Furthermore, we will only get here if the device (and
544 * EC) have been suspended.
545 *
546 * We now assume that the device is in laptop mode (0x01). This
547 * has the drawback that it will wake the device when unfolding
548 * it in studio mode, but it also allows us to avoid actively
549 * waiting for the EC to wake up, which may incur a notable
550 * delay.
551 */
552
553 dev_dbg(d->dev, "rqst: fixup: base-state quirk\n");
554
555 gsb_rqsx_response_success(gsb, &base_state, sizeof(base_state));
556 return AE_OK;
557 }
558
559 gsb_rqsx_response_error(gsb, -ENXIO);
560 return AE_OK;
561}
562
563static acpi_status san_rqst(struct san_data *d, struct gsb_buffer *buffer)
564{
565 u8 rspbuf[SAN_GSB_MAX_RESPONSE];
566 struct gsb_data_rqsx *gsb_rqst;
567 struct ssam_request rqst;
568 struct ssam_response rsp;
569 int status = 0;
570
571 gsb_rqst = san_validate_rqsx(d->dev, "RQST", buffer);
572 if (!gsb_rqst)
573 return AE_OK;
574
575 rqst.target_category = gsb_rqst->tc;
576 rqst.target_id = gsb_rqst->tid;
577 rqst.command_id = gsb_rqst->cid;
578 rqst.instance_id = gsb_rqst->iid;
579 rqst.flags = gsb_rqst->snc ? SSAM_REQUEST_HAS_RESPONSE : 0;
580 rqst.length = get_unaligned(&gsb_rqst->cdl);
581 rqst.payload = &gsb_rqst->pld[0];
582
583 rsp.capacity = ARRAY_SIZE(rspbuf);
584 rsp.length = 0;
585 rsp.pointer = &rspbuf[0];
586
587 /* Handle suspended device. */
588 if (d->dev->power.is_suspended) {
589 dev_warn(d->dev, "rqst: device is suspended, not executing\n");
590 return san_rqst_fixup_suspended(d, &rqst, buffer);
591 }
592
593 status = __ssam_retry(ssam_request_do_sync_onstack, SAN_REQUEST_NUM_TRIES,
594 d->ctrl, &rqst, &rsp, SAN_GSB_MAX_RQSX_PAYLOAD);
595
596 if (!status) {
597 gsb_rqsx_response_success(buffer, rsp.pointer, rsp.length);
598 } else {
599 dev_err(d->dev, "rqst: failed with error %d\n", status);
600 gsb_rqsx_response_error(buffer, status);
601 }
602
603 return AE_OK;
604}
605
606static acpi_status san_rqsg(struct san_data *d, struct gsb_buffer *buffer)
607{
608 struct gsb_data_rqsx *gsb_rqsg;
609 struct san_dgpu_event evt;
610 int status;
611
612 gsb_rqsg = san_validate_rqsx(d->dev, "RQSG", buffer);
613 if (!gsb_rqsg)
614 return AE_OK;
615
616 evt.category = gsb_rqsg->tc;
617 evt.target = gsb_rqsg->tid;
618 evt.command = gsb_rqsg->cid;
619 evt.instance = gsb_rqsg->iid;
620 evt.length = get_unaligned(&gsb_rqsg->cdl);
621 evt.payload = &gsb_rqsg->pld[0];
622
623 status = san_dgpu_notifier_call(&evt);
624 if (!status) {
625 gsb_rqsx_response_success(buffer, NULL, 0);
626 } else {
627 dev_err(d->dev, "rqsg: failed with error %d\n", status);
628 gsb_rqsx_response_error(buffer, status);
629 }
630
631 return AE_OK;
632}
633
634static acpi_status san_opreg_handler(u32 function, acpi_physical_address command,
635 u32 bits, u64 *value64, void *opreg_context,
636 void *region_context)
637{
638 struct san_data *d = to_san_data(opreg_context, info);
639 struct gsb_buffer *buffer = (struct gsb_buffer *)value64;
640 int accessor_type = (function & 0xFFFF0000) >> 16;
641
642 if (command != SAN_GSB_COMMAND) {
643 dev_warn(d->dev, "unsupported command: %#04llx\n", command);
644 return AE_OK;
645 }
646
647 if (accessor_type != ACPI_GSB_ACCESS_ATTRIB_RAW_PROCESS) {
648 dev_err(d->dev, "invalid access type: %#04x\n", accessor_type);
649 return AE_OK;
650 }
651
652 /* Buffer must have at least contain the command-value. */
653 if (buffer->len == 0) {
654 dev_err(d->dev, "request-package too small\n");
655 return AE_OK;
656 }
657
658 switch (buffer->data.in.cv) {
659 case SAN_GSB_REQUEST_CV_RQST:
660 return san_rqst(d, buffer);
661
662 case SAN_GSB_REQUEST_CV_ETWL:
663 return san_etwl(d, buffer);
664
665 case SAN_GSB_REQUEST_CV_RQSG:
666 return san_rqsg(d, buffer);
667
668 default:
669 dev_warn(d->dev, "unsupported SAN0 request (cv: %#04x)\n",
670 buffer->data.in.cv);
671 return AE_OK;
672 }
673}
674
675
676/* -- Driver setup. --------------------------------------------------------- */
677
678static int san_events_register(struct platform_device *pdev)
679{
680 struct san_data *d = platform_get_drvdata(pdev);
681 int status;
682
683 d->nf_bat.base.priority = 1;
684 d->nf_bat.base.fn = san_evt_bat_nf;
685 d->nf_bat.event.reg = SSAM_EVENT_REGISTRY_SAM;
686 d->nf_bat.event.id.target_category = SSAM_SSH_TC_BAT;
687 d->nf_bat.event.id.instance = 0;
688 d->nf_bat.event.mask = SSAM_EVENT_MASK_TARGET;
689 d->nf_bat.event.flags = SSAM_EVENT_SEQUENCED;
690
691 d->nf_tmp.base.priority = 1;
692 d->nf_tmp.base.fn = san_evt_tmp_nf;
693 d->nf_tmp.event.reg = SSAM_EVENT_REGISTRY_SAM;
694 d->nf_tmp.event.id.target_category = SSAM_SSH_TC_TMP;
695 d->nf_tmp.event.id.instance = 0;
696 d->nf_tmp.event.mask = SSAM_EVENT_MASK_TARGET;
697 d->nf_tmp.event.flags = SSAM_EVENT_SEQUENCED;
698
699 status = ssam_notifier_register(d->ctrl, &d->nf_bat);
700 if (status)
701 return status;
702
703 status = ssam_notifier_register(d->ctrl, &d->nf_tmp);
704 if (status)
705 ssam_notifier_unregister(d->ctrl, &d->nf_bat);
706
707 return status;
708}
709
710static void san_events_unregister(struct platform_device *pdev)
711{
712 struct san_data *d = platform_get_drvdata(pdev);
713
714 ssam_notifier_unregister(d->ctrl, &d->nf_bat);
715 ssam_notifier_unregister(d->ctrl, &d->nf_tmp);
716}
717
718#define san_consumer_printk(level, dev, handle, fmt, ...) \
719do { \
720 char *path = "<error getting consumer path>"; \
721 struct acpi_buffer buffer = { \
722 .length = ACPI_ALLOCATE_BUFFER, \
723 .pointer = NULL, \
724 }; \
725 \
726 if (ACPI_SUCCESS(acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer))) \
727 path = buffer.pointer; \
728 \
729 dev_##level(dev, "[%s]: " fmt, path, ##__VA_ARGS__); \
730 kfree(buffer.pointer); \
731} while (0)
732
733#define san_consumer_dbg(dev, handle, fmt, ...) \
734 san_consumer_printk(dbg, dev, handle, fmt, ##__VA_ARGS__)
735
736#define san_consumer_warn(dev, handle, fmt, ...) \
737 san_consumer_printk(warn, dev, handle, fmt, ##__VA_ARGS__)
738
739static acpi_status san_consumer_setup(acpi_handle handle, u32 lvl,
740 void *context, void **rv)
741{
742 const u32 flags = DL_FLAG_PM_RUNTIME | DL_FLAG_AUTOREMOVE_SUPPLIER;
743 struct platform_device *pdev = context;
744 struct acpi_device *adev;
745 struct device_link *link;
746
747 if (!acpi_device_dep(handle, ACPI_HANDLE(&pdev->dev)))
748 return AE_OK;
749
750 /* Ignore ACPI devices that are not present. */
751 adev = acpi_fetch_acpi_dev(handle);
752 if (!adev)
753 return AE_OK;
754
755 san_consumer_dbg(&pdev->dev, handle, "creating device link\n");
756
757 /* Try to set up device links, ignore but log errors. */
758 link = device_link_add(&adev->dev, &pdev->dev, flags);
759 if (!link) {
760 san_consumer_warn(&pdev->dev, handle, "failed to create device link\n");
761 return AE_OK;
762 }
763
764 return AE_OK;
765}
766
767static int san_consumer_links_setup(struct platform_device *pdev)
768{
769 acpi_status status;
770
771 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
772 ACPI_UINT32_MAX, san_consumer_setup, NULL,
773 pdev, NULL);
774
775 return status ? -EFAULT : 0;
776}
777
778static int san_probe(struct platform_device *pdev)
779{
780 struct acpi_device *san = ACPI_COMPANION(&pdev->dev);
781 struct ssam_controller *ctrl;
782 struct san_data *data;
783 acpi_status astatus;
784 int status;
785
786 ctrl = ssam_client_bind(&pdev->dev);
787 if (IS_ERR(ctrl))
788 return PTR_ERR(ctrl) == -ENODEV ? -EPROBE_DEFER : PTR_ERR(ctrl);
789
790 status = san_consumer_links_setup(pdev);
791 if (status)
792 return status;
793
794 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
795 if (!data)
796 return -ENOMEM;
797
798 data->dev = &pdev->dev;
799 data->ctrl = ctrl;
800
801 platform_set_drvdata(pdev, data);
802
803 astatus = acpi_install_address_space_handler(san->handle,
804 ACPI_ADR_SPACE_GSBUS,
805 &san_opreg_handler, NULL,
806 &data->info);
807 if (ACPI_FAILURE(astatus))
808 return -ENXIO;
809
810 status = san_events_register(pdev);
811 if (status)
812 goto err_enable_events;
813
814 status = san_set_rqsg_interface_device(&pdev->dev);
815 if (status)
816 goto err_install_dev;
817
818 acpi_dev_clear_dependencies(san);
819 return 0;
820
821err_install_dev:
822 san_events_unregister(pdev);
823err_enable_events:
824 acpi_remove_address_space_handler(san, ACPI_ADR_SPACE_GSBUS,
825 &san_opreg_handler);
826 return status;
827}
828
829static void san_remove(struct platform_device *pdev)
830{
831 acpi_handle san = ACPI_HANDLE(&pdev->dev);
832
833 san_set_rqsg_interface_device(NULL);
834 acpi_remove_address_space_handler(san, ACPI_ADR_SPACE_GSBUS,
835 &san_opreg_handler);
836 san_events_unregister(pdev);
837
838 /*
839 * We have unregistered our event sources. Now we need to ensure that
840 * all delayed works they may have spawned are run to completion.
841 */
842 flush_workqueue(san_wq);
843}
844
845static const struct acpi_device_id san_match[] = {
846 { "MSHW0091" },
847 { },
848};
849MODULE_DEVICE_TABLE(acpi, san_match);
850
851static struct platform_driver surface_acpi_notify = {
852 .probe = san_probe,
853 .remove_new = san_remove,
854 .driver = {
855 .name = "surface_acpi_notify",
856 .acpi_match_table = san_match,
857 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
858 },
859};
860
861static int __init san_init(void)
862{
863 int ret;
864
865 san_wq = alloc_workqueue("san_wq", 0, 0);
866 if (!san_wq)
867 return -ENOMEM;
868 ret = platform_driver_register(&surface_acpi_notify);
869 if (ret)
870 destroy_workqueue(san_wq);
871 return ret;
872}
873module_init(san_init);
874
875static void __exit san_exit(void)
876{
877 platform_driver_unregister(&surface_acpi_notify);
878 destroy_workqueue(san_wq);
879}
880module_exit(san_exit);
881
882MODULE_AUTHOR("Maximilian Luz <luzmaximilian@gmail.com>");
883MODULE_DESCRIPTION("Surface ACPI Notify driver for Surface System Aggregator Module");
884MODULE_LICENSE("GPL");