1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2021-2022 NVIDIA Corporation
4 *
5 * Author: Dipen Patel <dipenp@nvidia.com>
6 */
7
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/err.h>
11 #include <linux/slab.h>
12 #include <linux/of.h>
13 #include <linux/mutex.h>
14 #include <linux/uaccess.h>
15 #include <linux/hte.h>
16 #include <linux/delay.h>
17 #include <linux/debugfs.h>
18 #include <linux/device.h>
19
20 #define HTE_TS_NAME_LEN 10
21
22 /* Global list of the HTE devices */
23 static DEFINE_SPINLOCK(hte_lock);
24 static LIST_HEAD(hte_devices);
25
26 enum {
27 HTE_TS_REGISTERED,
28 HTE_TS_REQ,
29 HTE_TS_DISABLE,
30 HTE_TS_QUEUE_WK,
31 };
32
33 /**
34 * struct hte_ts_info - Information related to requested timestamp.
35 *
36 * @xlated_id: Timestamp ID as understood between HTE subsys and HTE provider,
37 * See xlate callback API.
38 * @flags: Flags holding state information.
39 * @hte_cb_flags: Callback related flags.
40 * @seq: Timestamp sequence counter.
41 * @line_name: HTE allocated line name.
42 * @free_attr_name: If set, free the attr name.
43 * @cb: A nonsleeping callback function provided by clients.
44 * @tcb: A secondary sleeping callback function provided by clients.
45 * @dropped_ts: Dropped timestamps.
46 * @slock: Spin lock to synchronize between disable/enable,
47 * request/release APIs.
48 * @cb_work: callback workqueue, used when tcb is specified.
49 * @req_mlock: Lock during timestamp request/release APIs.
50 * @ts_dbg_root: Root for the debug fs.
51 * @gdev: HTE abstract device that this timestamp information belongs to.
52 * @cl_data: Client specific data.
53 */
54 struct hte_ts_info {
55 u32 xlated_id;
56 unsigned long flags;
57 unsigned long hte_cb_flags;
58 u64 seq;
59 char *line_name;
60 bool free_attr_name;
61 hte_ts_cb_t cb;
62 hte_ts_sec_cb_t tcb;
63 atomic_t dropped_ts;
64 spinlock_t slock;
65 struct work_struct cb_work;
66 struct mutex req_mlock;
67 struct dentry *ts_dbg_root;
68 struct hte_device *gdev;
69 void *cl_data;
70 };
71
72 /**
73 * struct hte_device - HTE abstract device
74 * @nlines: Number of entities this device supports.
75 * @ts_req: Total number of entities requested.
76 * @sdev: Device used at various debug prints.
77 * @dbg_root: Root directory for debug fs.
78 * @list: List node to store hte_device for each provider.
79 * @chip: HTE chip providing this HTE device.
80 * @owner: helps prevent removal of modules when in use.
81 * @ei: Timestamp information.
82 */
83 struct hte_device {
84 u32 nlines;
85 atomic_t ts_req;
86 struct device *sdev;
87 struct dentry *dbg_root;
88 struct list_head list;
89 struct hte_chip *chip;
90 struct module *owner;
91 struct hte_ts_info ei[];
92 };
93
94 #ifdef CONFIG_DEBUG_FS
95
96 static struct dentry *hte_root;
97
hte_subsys_dbgfs_init(void)98 static int __init hte_subsys_dbgfs_init(void)
99 {
100 /* creates /sys/kernel/debug/hte/ */
101 hte_root = debugfs_create_dir("hte", NULL);
102
103 return 0;
104 }
105 subsys_initcall(hte_subsys_dbgfs_init);
106
hte_chip_dbgfs_init(struct hte_device * gdev)107 static void hte_chip_dbgfs_init(struct hte_device *gdev)
108 {
109 const struct hte_chip *chip = gdev->chip;
110 const char *name = chip->name ? chip->name : dev_name(chip->dev);
111
112 gdev->dbg_root = debugfs_create_dir(name, hte_root);
113
114 debugfs_create_atomic_t("ts_requested", 0444, gdev->dbg_root,
115 &gdev->ts_req);
116 debugfs_create_u32("total_ts", 0444, gdev->dbg_root,
117 &gdev->nlines);
118 }
119
hte_ts_dbgfs_init(const char * name,struct hte_ts_info * ei)120 static void hte_ts_dbgfs_init(const char *name, struct hte_ts_info *ei)
121 {
122 if (!ei->gdev->dbg_root || !name)
123 return;
124
125 ei->ts_dbg_root = debugfs_create_dir(name, ei->gdev->dbg_root);
126
127 debugfs_create_atomic_t("dropped_timestamps", 0444, ei->ts_dbg_root,
128 &ei->dropped_ts);
129 }
130
131 #else
132
hte_chip_dbgfs_init(struct hte_device * gdev)133 static void hte_chip_dbgfs_init(struct hte_device *gdev)
134 {
135 }
136
hte_ts_dbgfs_init(const char * name,struct hte_ts_info * ei)137 static void hte_ts_dbgfs_init(const char *name, struct hte_ts_info *ei)
138 {
139 }
140
141 #endif
142
143 /**
144 * hte_ts_put() - Release and disable timestamp for the given desc.
145 *
146 * @desc: timestamp descriptor.
147 *
148 * Context: debugfs_remove_recursive() function call may use sleeping locks,
149 * not suitable from atomic context.
150 * Returns: 0 on success or a negative error code on failure.
151 */
hte_ts_put(struct hte_ts_desc * desc)152 int hte_ts_put(struct hte_ts_desc *desc)
153 {
154 int ret = 0;
155 unsigned long flag;
156 struct hte_device *gdev;
157 struct hte_ts_info *ei;
158
159 if (!desc)
160 return -EINVAL;
161
162 ei = desc->hte_data;
163
164 if (!ei || !ei->gdev)
165 return -EINVAL;
166
167 gdev = ei->gdev;
168
169 mutex_lock(&ei->req_mlock);
170
171 if (unlikely(!test_bit(HTE_TS_REQ, &ei->flags) &&
172 !test_bit(HTE_TS_REGISTERED, &ei->flags))) {
173 dev_info(gdev->sdev, "id:%d is not requested\n",
174 desc->attr.line_id);
175 ret = -EINVAL;
176 goto unlock;
177 }
178
179 if (unlikely(!test_bit(HTE_TS_REQ, &ei->flags) &&
180 test_bit(HTE_TS_REGISTERED, &ei->flags))) {
181 dev_info(gdev->sdev, "id:%d is registered but not requested\n",
182 desc->attr.line_id);
183 ret = -EINVAL;
184 goto unlock;
185 }
186
187 if (test_bit(HTE_TS_REQ, &ei->flags) &&
188 !test_bit(HTE_TS_REGISTERED, &ei->flags)) {
189 clear_bit(HTE_TS_REQ, &ei->flags);
190 desc->hte_data = NULL;
191 ret = 0;
192 goto mod_put;
193 }
194
195 ret = gdev->chip->ops->release(gdev->chip, desc, ei->xlated_id);
196 if (ret) {
197 dev_err(gdev->sdev, "id: %d free failed\n",
198 desc->attr.line_id);
199 goto unlock;
200 }
201
202 kfree(ei->line_name);
203 if (ei->free_attr_name)
204 kfree_const(desc->attr.name);
205
206 debugfs_remove_recursive(ei->ts_dbg_root);
207
208 spin_lock_irqsave(&ei->slock, flag);
209
210 if (test_bit(HTE_TS_QUEUE_WK, &ei->flags)) {
211 spin_unlock_irqrestore(&ei->slock, flag);
212 flush_work(&ei->cb_work);
213 spin_lock_irqsave(&ei->slock, flag);
214 }
215
216 atomic_dec(&gdev->ts_req);
217 atomic_set(&ei->dropped_ts, 0);
218
219 ei->seq = 1;
220 ei->flags = 0;
221 desc->hte_data = NULL;
222
223 spin_unlock_irqrestore(&ei->slock, flag);
224
225 ei->cb = NULL;
226 ei->tcb = NULL;
227 ei->cl_data = NULL;
228
229 mod_put:
230 module_put(gdev->owner);
231 unlock:
232 mutex_unlock(&ei->req_mlock);
233 dev_dbg(gdev->sdev, "release id: %d\n", desc->attr.line_id);
234
235 return ret;
236 }
237 EXPORT_SYMBOL_GPL(hte_ts_put);
238
hte_ts_dis_en_common(struct hte_ts_desc * desc,bool en)239 static int hte_ts_dis_en_common(struct hte_ts_desc *desc, bool en)
240 {
241 u32 ts_id;
242 struct hte_device *gdev;
243 struct hte_ts_info *ei;
244 int ret;
245 unsigned long flag;
246
247 if (!desc)
248 return -EINVAL;
249
250 ei = desc->hte_data;
251
252 if (!ei || !ei->gdev)
253 return -EINVAL;
254
255 gdev = ei->gdev;
256 ts_id = desc->attr.line_id;
257
258 mutex_lock(&ei->req_mlock);
259
260 if (!test_bit(HTE_TS_REGISTERED, &ei->flags)) {
261 dev_dbg(gdev->sdev, "id:%d is not registered", ts_id);
262 ret = -EUSERS;
263 goto out;
264 }
265
266 spin_lock_irqsave(&ei->slock, flag);
267
268 if (en) {
269 if (!test_bit(HTE_TS_DISABLE, &ei->flags)) {
270 ret = 0;
271 goto out_unlock;
272 }
273
274 spin_unlock_irqrestore(&ei->slock, flag);
275 ret = gdev->chip->ops->enable(gdev->chip, ei->xlated_id);
276 if (ret) {
277 dev_warn(gdev->sdev, "id: %d enable failed\n",
278 ts_id);
279 goto out;
280 }
281
282 spin_lock_irqsave(&ei->slock, flag);
283 clear_bit(HTE_TS_DISABLE, &ei->flags);
284 } else {
285 if (test_bit(HTE_TS_DISABLE, &ei->flags)) {
286 ret = 0;
287 goto out_unlock;
288 }
289
290 spin_unlock_irqrestore(&ei->slock, flag);
291 ret = gdev->chip->ops->disable(gdev->chip, ei->xlated_id);
292 if (ret) {
293 dev_warn(gdev->sdev, "id: %d disable failed\n",
294 ts_id);
295 goto out;
296 }
297
298 spin_lock_irqsave(&ei->slock, flag);
299 set_bit(HTE_TS_DISABLE, &ei->flags);
300 }
301
302 out_unlock:
303 spin_unlock_irqrestore(&ei->slock, flag);
304 out:
305 mutex_unlock(&ei->req_mlock);
306 return ret;
307 }
308
309 /**
310 * hte_disable_ts() - Disable timestamp on given descriptor.
311 *
312 * The API does not release any resources associated with desc.
313 *
314 * @desc: ts descriptor, this is the same as returned by the request API.
315 *
316 * Context: Holds mutex lock, not suitable from atomic context.
317 * Returns: 0 on success or a negative error code on failure.
318 */
hte_disable_ts(struct hte_ts_desc * desc)319 int hte_disable_ts(struct hte_ts_desc *desc)
320 {
321 return hte_ts_dis_en_common(desc, false);
322 }
323 EXPORT_SYMBOL_GPL(hte_disable_ts);
324
325 /**
326 * hte_enable_ts() - Enable timestamp on given descriptor.
327 *
328 * @desc: ts descriptor, this is the same as returned by the request API.
329 *
330 * Context: Holds mutex lock, not suitable from atomic context.
331 * Returns: 0 on success or a negative error code on failure.
332 */
hte_enable_ts(struct hte_ts_desc * desc)333 int hte_enable_ts(struct hte_ts_desc *desc)
334 {
335 return hte_ts_dis_en_common(desc, true);
336 }
337 EXPORT_SYMBOL_GPL(hte_enable_ts);
338
hte_do_cb_work(struct work_struct * w)339 static void hte_do_cb_work(struct work_struct *w)
340 {
341 unsigned long flag;
342 struct hte_ts_info *ei = container_of(w, struct hte_ts_info, cb_work);
343
344 if (unlikely(!ei->tcb))
345 return;
346
347 ei->tcb(ei->cl_data);
348
349 spin_lock_irqsave(&ei->slock, flag);
350 clear_bit(HTE_TS_QUEUE_WK, &ei->flags);
351 spin_unlock_irqrestore(&ei->slock, flag);
352 }
353
__hte_req_ts(struct hte_ts_desc * desc,hte_ts_cb_t cb,hte_ts_sec_cb_t tcb,void * data)354 static int __hte_req_ts(struct hte_ts_desc *desc, hte_ts_cb_t cb,
355 hte_ts_sec_cb_t tcb, void *data)
356 {
357 int ret;
358 struct hte_device *gdev;
359 struct hte_ts_info *ei = desc->hte_data;
360
361 gdev = ei->gdev;
362 /*
363 * There is a chance that multiple consumers requesting same entity,
364 * lock here.
365 */
366 mutex_lock(&ei->req_mlock);
367
368 if (test_bit(HTE_TS_REGISTERED, &ei->flags) ||
369 !test_bit(HTE_TS_REQ, &ei->flags)) {
370 dev_dbg(gdev->chip->dev, "id:%u req failed\n",
371 desc->attr.line_id);
372 ret = -EUSERS;
373 goto unlock;
374 }
375
376 ei->cb = cb;
377 ei->tcb = tcb;
378 if (tcb)
379 INIT_WORK(&ei->cb_work, hte_do_cb_work);
380
381 ret = gdev->chip->ops->request(gdev->chip, desc, ei->xlated_id);
382 if (ret < 0) {
383 dev_err(gdev->chip->dev, "ts request failed\n");
384 goto unlock;
385 }
386
387 ei->cl_data = data;
388 ei->seq = 1;
389
390 atomic_inc(&gdev->ts_req);
391
392 ei->line_name = NULL;
393 if (!desc->attr.name) {
394 ei->line_name = kzalloc(HTE_TS_NAME_LEN, GFP_KERNEL);
395 if (ei->line_name)
396 scnprintf(ei->line_name, HTE_TS_NAME_LEN, "ts_%u",
397 desc->attr.line_id);
398 }
399
400 hte_ts_dbgfs_init(desc->attr.name == NULL ?
401 ei->line_name : desc->attr.name, ei);
402 set_bit(HTE_TS_REGISTERED, &ei->flags);
403
404 dev_dbg(gdev->chip->dev, "id: %u, xlated id:%u",
405 desc->attr.line_id, ei->xlated_id);
406
407 ret = 0;
408
409 unlock:
410 mutex_unlock(&ei->req_mlock);
411
412 return ret;
413 }
414
hte_bind_ts_info_locked(struct hte_ts_info * ei,struct hte_ts_desc * desc,u32 x_id)415 static int hte_bind_ts_info_locked(struct hte_ts_info *ei,
416 struct hte_ts_desc *desc, u32 x_id)
417 {
418 int ret = 0;
419
420 mutex_lock(&ei->req_mlock);
421
422 if (test_bit(HTE_TS_REQ, &ei->flags)) {
423 dev_dbg(ei->gdev->chip->dev, "id:%u is already requested\n",
424 desc->attr.line_id);
425 ret = -EUSERS;
426 goto out;
427 }
428
429 set_bit(HTE_TS_REQ, &ei->flags);
430 desc->hte_data = ei;
431 ei->xlated_id = x_id;
432
433 out:
434 mutex_unlock(&ei->req_mlock);
435
436 return ret;
437 }
438
of_node_to_htedevice(struct device_node * np)439 static struct hte_device *of_node_to_htedevice(struct device_node *np)
440 {
441 struct hte_device *gdev;
442
443 spin_lock(&hte_lock);
444
445 list_for_each_entry(gdev, &hte_devices, list)
446 if (gdev->chip && gdev->chip->dev &&
447 device_match_of_node(gdev->chip->dev, np)) {
448 spin_unlock(&hte_lock);
449 return gdev;
450 }
451
452 spin_unlock(&hte_lock);
453
454 return ERR_PTR(-ENODEV);
455 }
456
hte_find_dev_from_linedata(struct hte_ts_desc * desc)457 static struct hte_device *hte_find_dev_from_linedata(struct hte_ts_desc *desc)
458 {
459 struct hte_device *gdev;
460
461 spin_lock(&hte_lock);
462
463 list_for_each_entry(gdev, &hte_devices, list)
464 if (gdev->chip && gdev->chip->match_from_linedata) {
465 if (!gdev->chip->match_from_linedata(gdev->chip, desc))
466 continue;
467 spin_unlock(&hte_lock);
468 return gdev;
469 }
470
471 spin_unlock(&hte_lock);
472
473 return ERR_PTR(-ENODEV);
474 }
475
476 /**
477 * of_hte_req_count - Return the number of entities to timestamp.
478 *
479 * The function returns the total count of the requested entities to timestamp
480 * by parsing device tree.
481 *
482 * @dev: The HTE consumer.
483 *
484 * Returns: Positive number on success, -ENOENT if no entries,
485 * -EINVAL for other errors.
486 */
of_hte_req_count(struct device * dev)487 int of_hte_req_count(struct device *dev)
488 {
489 int count;
490
491 if (!dev || !dev->of_node)
492 return -EINVAL;
493
494 count = of_count_phandle_with_args(dev->of_node, "timestamps",
495 "#timestamp-cells");
496
497 return count ? count : -ENOENT;
498 }
499 EXPORT_SYMBOL_GPL(of_hte_req_count);
500
hte_get_dev(struct hte_ts_desc * desc)501 static inline struct hte_device *hte_get_dev(struct hte_ts_desc *desc)
502 {
503 return hte_find_dev_from_linedata(desc);
504 }
505
hte_of_get_dev(struct device * dev,struct hte_ts_desc * desc,int index,struct of_phandle_args * args,bool * free_name)506 static struct hte_device *hte_of_get_dev(struct device *dev,
507 struct hte_ts_desc *desc,
508 int index,
509 struct of_phandle_args *args,
510 bool *free_name)
511 {
512 int ret;
513 struct device_node *np;
514 char *temp;
515
516 if (!dev->of_node)
517 return ERR_PTR(-EINVAL);
518
519 np = dev->of_node;
520
521 if (!of_property_present(np, "timestamp-names")) {
522 /* Let hte core construct it during request time */
523 desc->attr.name = NULL;
524 } else {
525 ret = of_property_read_string_index(np, "timestamp-names",
526 index, &desc->attr.name);
527 if (ret) {
528 pr_err("can't parse \"timestamp-names\" property\n");
529 return ERR_PTR(ret);
530 }
531 *free_name = false;
532 if (desc->attr.name) {
533 temp = skip_spaces(desc->attr.name);
534 if (!*temp)
535 desc->attr.name = NULL;
536 }
537 }
538
539 ret = of_parse_phandle_with_args(np, "timestamps", "#timestamp-cells",
540 index, args);
541 if (ret) {
542 pr_err("%s(): can't parse \"timestamps\" property\n",
543 __func__);
544 return ERR_PTR(ret);
545 }
546
547 of_node_put(args->np);
548
549 return of_node_to_htedevice(args->np);
550 }
551
552 /**
553 * hte_ts_get() - The function to initialize and obtain HTE desc.
554 *
555 * The function initializes the consumer provided HTE descriptor. If consumer
556 * has device tree node, index is used to parse the line id and other details.
557 * The function needs to be called before using any request APIs.
558 *
559 * @dev: HTE consumer/client device, used in case of parsing device tree node.
560 * @desc: Pre-allocated timestamp descriptor.
561 * @index: The index will be used as an index to parse line_id from the
562 * device tree node if node is present.
563 *
564 * Context: Holds mutex lock.
565 * Returns: Returns 0 on success or negative error code on failure.
566 */
hte_ts_get(struct device * dev,struct hte_ts_desc * desc,int index)567 int hte_ts_get(struct device *dev, struct hte_ts_desc *desc, int index)
568 {
569 struct hte_device *gdev;
570 struct hte_ts_info *ei;
571 const struct fwnode_handle *fwnode;
572 struct of_phandle_args args;
573 u32 xlated_id;
574 int ret;
575 bool free_name = false;
576
577 if (!desc)
578 return -EINVAL;
579
580 fwnode = dev ? dev_fwnode(dev) : NULL;
581
582 if (is_of_node(fwnode))
583 gdev = hte_of_get_dev(dev, desc, index, &args, &free_name);
584 else
585 gdev = hte_get_dev(desc);
586
587 if (IS_ERR(gdev)) {
588 pr_err("%s() no hte dev found\n", __func__);
589 return PTR_ERR(gdev);
590 }
591
592 if (!try_module_get(gdev->owner))
593 return -ENODEV;
594
595 if (!gdev->chip) {
596 pr_err("%s(): requested id does not have provider\n",
597 __func__);
598 ret = -ENODEV;
599 goto put;
600 }
601
602 if (is_of_node(fwnode)) {
603 if (!gdev->chip->xlate_of)
604 ret = -EINVAL;
605 else
606 ret = gdev->chip->xlate_of(gdev->chip, &args,
607 desc, &xlated_id);
608 } else {
609 if (!gdev->chip->xlate_plat)
610 ret = -EINVAL;
611 else
612 ret = gdev->chip->xlate_plat(gdev->chip, desc,
613 &xlated_id);
614 }
615
616 if (ret < 0)
617 goto put;
618
619 ei = &gdev->ei[xlated_id];
620
621 ret = hte_bind_ts_info_locked(ei, desc, xlated_id);
622 if (ret)
623 goto put;
624
625 ei->free_attr_name = free_name;
626
627 return 0;
628
629 put:
630 module_put(gdev->owner);
631 return ret;
632 }
633 EXPORT_SYMBOL_GPL(hte_ts_get);
634
__devm_hte_release_ts(void * res)635 static void __devm_hte_release_ts(void *res)
636 {
637 hte_ts_put(res);
638 }
639
640 /**
641 * hte_request_ts_ns() - The API to request and enable hardware timestamp in
642 * nanoseconds.
643 *
644 * The entity is provider specific for example, GPIO lines, signals, buses
645 * etc...The API allocates necessary resources and enables the timestamp.
646 *
647 * @desc: Pre-allocated and initialized timestamp descriptor.
648 * @cb: Callback to push the timestamp data to consumer.
649 * @tcb: Optional callback. If its provided, subsystem initializes
650 * workqueue. It is called when cb returns HTE_RUN_SECOND_CB.
651 * @data: Client data, used during cb and tcb callbacks.
652 *
653 * Context: Holds mutex lock.
654 * Returns: Returns 0 on success or negative error code on failure.
655 */
hte_request_ts_ns(struct hte_ts_desc * desc,hte_ts_cb_t cb,hte_ts_sec_cb_t tcb,void * data)656 int hte_request_ts_ns(struct hte_ts_desc *desc, hte_ts_cb_t cb,
657 hte_ts_sec_cb_t tcb, void *data)
658 {
659 int ret;
660 struct hte_ts_info *ei;
661
662 if (!desc || !desc->hte_data || !cb)
663 return -EINVAL;
664
665 ei = desc->hte_data;
666 if (!ei || !ei->gdev)
667 return -EINVAL;
668
669 ret = __hte_req_ts(desc, cb, tcb, data);
670 if (ret < 0) {
671 dev_err(ei->gdev->chip->dev,
672 "failed to request id: %d\n", desc->attr.line_id);
673 return ret;
674 }
675
676 return 0;
677 }
678 EXPORT_SYMBOL_GPL(hte_request_ts_ns);
679
680 /**
681 * devm_hte_request_ts_ns() - Resource managed API to request and enable
682 * hardware timestamp in nanoseconds.
683 *
684 * The entity is provider specific for example, GPIO lines, signals, buses
685 * etc...The API allocates necessary resources and enables the timestamp. It
686 * deallocates and disables automatically when the consumer exits.
687 *
688 * @dev: HTE consumer/client device.
689 * @desc: Pre-allocated and initialized timestamp descriptor.
690 * @cb: Callback to push the timestamp data to consumer.
691 * @tcb: Optional callback. If its provided, subsystem initializes
692 * workqueue. It is called when cb returns HTE_RUN_SECOND_CB.
693 * @data: Client data, used during cb and tcb callbacks.
694 *
695 * Context: Holds mutex lock.
696 * Returns: Returns 0 on success or negative error code on failure.
697 */
devm_hte_request_ts_ns(struct device * dev,struct hte_ts_desc * desc,hte_ts_cb_t cb,hte_ts_sec_cb_t tcb,void * data)698 int devm_hte_request_ts_ns(struct device *dev, struct hte_ts_desc *desc,
699 hte_ts_cb_t cb, hte_ts_sec_cb_t tcb,
700 void *data)
701 {
702 int err;
703
704 if (!dev)
705 return -EINVAL;
706
707 err = hte_request_ts_ns(desc, cb, tcb, data);
708 if (err)
709 return err;
710
711 err = devm_add_action_or_reset(dev, __devm_hte_release_ts, desc);
712 if (err)
713 return err;
714
715 return 0;
716 }
717 EXPORT_SYMBOL_GPL(devm_hte_request_ts_ns);
718
719 /**
720 * hte_init_line_attr() - Initialize line attributes.
721 *
722 * Zeroes out line attributes and initializes with provided arguments.
723 * The function needs to be called before calling any consumer facing
724 * functions.
725 *
726 * @desc: Pre-allocated timestamp descriptor.
727 * @line_id: line id.
728 * @edge_flags: edge flags related to line_id.
729 * @name: name of the line.
730 * @data: line data related to line_id.
731 *
732 * Context: Any.
733 * Returns: 0 on success or negative error code for the failure.
734 */
hte_init_line_attr(struct hte_ts_desc * desc,u32 line_id,unsigned long edge_flags,const char * name,void * data)735 int hte_init_line_attr(struct hte_ts_desc *desc, u32 line_id,
736 unsigned long edge_flags, const char *name, void *data)
737 {
738 if (!desc)
739 return -EINVAL;
740
741 memset(&desc->attr, 0, sizeof(desc->attr));
742
743 desc->attr.edge_flags = edge_flags;
744 desc->attr.line_id = line_id;
745 desc->attr.line_data = data;
746 if (name) {
747 name = kstrdup_const(name, GFP_KERNEL);
748 if (!name)
749 return -ENOMEM;
750 }
751
752 desc->attr.name = name;
753
754 return 0;
755 }
756 EXPORT_SYMBOL_GPL(hte_init_line_attr);
757
758 /**
759 * hte_get_clk_src_info() - Get the clock source information for a ts
760 * descriptor.
761 *
762 * @desc: ts descriptor, same as returned from request API.
763 * @ci: The API fills this structure with the clock information data.
764 *
765 * Context: Any context.
766 * Returns: 0 on success else negative error code on failure.
767 */
hte_get_clk_src_info(const struct hte_ts_desc * desc,struct hte_clk_info * ci)768 int hte_get_clk_src_info(const struct hte_ts_desc *desc,
769 struct hte_clk_info *ci)
770 {
771 struct hte_chip *chip;
772 struct hte_ts_info *ei;
773
774 if (!desc || !desc->hte_data || !ci) {
775 pr_debug("%s:%d\n", __func__, __LINE__);
776 return -EINVAL;
777 }
778
779 ei = desc->hte_data;
780 if (!ei->gdev || !ei->gdev->chip)
781 return -EINVAL;
782
783 chip = ei->gdev->chip;
784 if (!chip->ops->get_clk_src_info)
785 return -EOPNOTSUPP;
786
787 return chip->ops->get_clk_src_info(chip, ci);
788 }
789 EXPORT_SYMBOL_GPL(hte_get_clk_src_info);
790
791 /**
792 * hte_push_ts_ns() - Push timestamp data in nanoseconds.
793 *
794 * It is used by the provider to push timestamp data.
795 *
796 * @chip: The HTE chip, used during the registration.
797 * @xlated_id: entity id understood by both subsystem and provider, this is
798 * obtained from xlate callback during request API.
799 * @data: timestamp data.
800 *
801 * Returns: 0 on success or a negative error code on failure.
802 */
hte_push_ts_ns(const struct hte_chip * chip,u32 xlated_id,struct hte_ts_data * data)803 int hte_push_ts_ns(const struct hte_chip *chip, u32 xlated_id,
804 struct hte_ts_data *data)
805 {
806 enum hte_return ret;
807 int st = 0;
808 struct hte_ts_info *ei;
809 unsigned long flag;
810
811 if (!chip || !data || !chip->gdev)
812 return -EINVAL;
813
814 if (xlated_id >= chip->nlines)
815 return -EINVAL;
816
817 ei = &chip->gdev->ei[xlated_id];
818
819 spin_lock_irqsave(&ei->slock, flag);
820
821 /* timestamp sequence counter */
822 data->seq = ei->seq++;
823
824 if (!test_bit(HTE_TS_REGISTERED, &ei->flags) ||
825 test_bit(HTE_TS_DISABLE, &ei->flags)) {
826 dev_dbg(chip->dev, "Unknown timestamp push\n");
827 atomic_inc(&ei->dropped_ts);
828 st = -EINVAL;
829 goto unlock;
830 }
831
832 ret = ei->cb(data, ei->cl_data);
833 if (ret == HTE_RUN_SECOND_CB && ei->tcb) {
834 queue_work(system_unbound_wq, &ei->cb_work);
835 set_bit(HTE_TS_QUEUE_WK, &ei->flags);
836 }
837
838 unlock:
839 spin_unlock_irqrestore(&ei->slock, flag);
840
841 return st;
842 }
843 EXPORT_SYMBOL_GPL(hte_push_ts_ns);
844
hte_register_chip(struct hte_chip * chip)845 static int hte_register_chip(struct hte_chip *chip)
846 {
847 struct hte_device *gdev;
848 u32 i;
849
850 if (!chip || !chip->dev || !chip->dev->of_node)
851 return -EINVAL;
852
853 if (!chip->ops || !chip->ops->request || !chip->ops->release) {
854 dev_err(chip->dev, "Driver needs to provide ops\n");
855 return -EINVAL;
856 }
857
858 gdev = kzalloc(struct_size(gdev, ei, chip->nlines), GFP_KERNEL);
859 if (!gdev)
860 return -ENOMEM;
861
862 gdev->chip = chip;
863 chip->gdev = gdev;
864 gdev->nlines = chip->nlines;
865 gdev->sdev = chip->dev;
866
867 for (i = 0; i < chip->nlines; i++) {
868 gdev->ei[i].gdev = gdev;
869 mutex_init(&gdev->ei[i].req_mlock);
870 spin_lock_init(&gdev->ei[i].slock);
871 }
872
873 if (chip->dev->driver)
874 gdev->owner = chip->dev->driver->owner;
875 else
876 gdev->owner = THIS_MODULE;
877
878 of_node_get(chip->dev->of_node);
879
880 INIT_LIST_HEAD(&gdev->list);
881
882 spin_lock(&hte_lock);
883 list_add_tail(&gdev->list, &hte_devices);
884 spin_unlock(&hte_lock);
885
886 hte_chip_dbgfs_init(gdev);
887
888 dev_dbg(chip->dev, "Added hte chip\n");
889
890 return 0;
891 }
892
hte_unregister_chip(struct hte_chip * chip)893 static int hte_unregister_chip(struct hte_chip *chip)
894 {
895 struct hte_device *gdev;
896
897 if (!chip)
898 return -EINVAL;
899
900 gdev = chip->gdev;
901
902 spin_lock(&hte_lock);
903 list_del(&gdev->list);
904 spin_unlock(&hte_lock);
905
906 gdev->chip = NULL;
907
908 of_node_put(chip->dev->of_node);
909 debugfs_remove_recursive(gdev->dbg_root);
910 kfree(gdev);
911
912 dev_dbg(chip->dev, "Removed hte chip\n");
913
914 return 0;
915 }
916
_hte_devm_unregister_chip(void * chip)917 static void _hte_devm_unregister_chip(void *chip)
918 {
919 hte_unregister_chip(chip);
920 }
921
922 /**
923 * devm_hte_register_chip() - Resource managed API to register HTE chip.
924 *
925 * It is used by the provider to register itself with the HTE subsystem.
926 * The unregistration is done automatically when the provider exits.
927 *
928 * @chip: the HTE chip to add to subsystem.
929 *
930 * Returns: 0 on success or a negative error code on failure.
931 */
devm_hte_register_chip(struct hte_chip * chip)932 int devm_hte_register_chip(struct hte_chip *chip)
933 {
934 int err;
935
936 err = hte_register_chip(chip);
937 if (err)
938 return err;
939
940 err = devm_add_action_or_reset(chip->dev, _hte_devm_unregister_chip,
941 chip);
942 if (err)
943 return err;
944
945 return 0;
946 }
947 EXPORT_SYMBOL_GPL(devm_hte_register_chip);
948