nbd: Respect max_part for all partition scans
[linux-2.6-microblaze.git] / drivers / ptp / ptp_clock.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * PTP 1588 clock support
4  *
5  * Copyright (C) 2010 OMICRON electronics GmbH
6  */
7 #include <linux/idr.h>
8 #include <linux/device.h>
9 #include <linux/err.h>
10 #include <linux/init.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/posix-clock.h>
14 #include <linux/pps_kernel.h>
15 #include <linux/slab.h>
16 #include <linux/syscalls.h>
17 #include <linux/uaccess.h>
18 #include <uapi/linux/sched/types.h>
19
20 #include "ptp_private.h"
21
22 #define PTP_MAX_ALARMS 4
23 #define PTP_PPS_DEFAULTS (PPS_CAPTUREASSERT | PPS_OFFSETASSERT)
24 #define PTP_PPS_EVENT PPS_CAPTUREASSERT
25 #define PTP_PPS_MODE (PTP_PPS_DEFAULTS | PPS_CANWAIT | PPS_TSFMT_TSPEC)
26
27 /* private globals */
28
29 static dev_t ptp_devt;
30 static struct class *ptp_class;
31
32 static DEFINE_IDA(ptp_clocks_map);
33
34 /* time stamp event queue operations */
35
36 static inline int queue_free(struct timestamp_event_queue *q)
37 {
38         return PTP_MAX_TIMESTAMPS - queue_cnt(q) - 1;
39 }
40
41 static void enqueue_external_timestamp(struct timestamp_event_queue *queue,
42                                        struct ptp_clock_event *src)
43 {
44         struct ptp_extts_event *dst;
45         unsigned long flags;
46         s64 seconds;
47         u32 remainder;
48
49         seconds = div_u64_rem(src->timestamp, 1000000000, &remainder);
50
51         spin_lock_irqsave(&queue->lock, flags);
52
53         dst = &queue->buf[queue->tail];
54         dst->index = src->index;
55         dst->t.sec = seconds;
56         dst->t.nsec = remainder;
57
58         if (!queue_free(queue))
59                 queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
60
61         queue->tail = (queue->tail + 1) % PTP_MAX_TIMESTAMPS;
62
63         spin_unlock_irqrestore(&queue->lock, flags);
64 }
65
66 s32 scaled_ppm_to_ppb(long ppm)
67 {
68         /*
69          * The 'freq' field in the 'struct timex' is in parts per
70          * million, but with a 16 bit binary fractional field.
71          *
72          * We want to calculate
73          *
74          *    ppb = scaled_ppm * 1000 / 2^16
75          *
76          * which simplifies to
77          *
78          *    ppb = scaled_ppm * 125 / 2^13
79          */
80         s64 ppb = 1 + ppm;
81         ppb *= 125;
82         ppb >>= 13;
83         return (s32) ppb;
84 }
85 EXPORT_SYMBOL(scaled_ppm_to_ppb);
86
87 /* posix clock implementation */
88
89 static int ptp_clock_getres(struct posix_clock *pc, struct timespec64 *tp)
90 {
91         tp->tv_sec = 0;
92         tp->tv_nsec = 1;
93         return 0;
94 }
95
96 static int ptp_clock_settime(struct posix_clock *pc, const struct timespec64 *tp)
97 {
98         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
99
100         return  ptp->info->settime64(ptp->info, tp);
101 }
102
103 static int ptp_clock_gettime(struct posix_clock *pc, struct timespec64 *tp)
104 {
105         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
106         int err;
107
108         if (ptp->info->gettimex64)
109                 err = ptp->info->gettimex64(ptp->info, tp, NULL);
110         else
111                 err = ptp->info->gettime64(ptp->info, tp);
112         return err;
113 }
114
115 static int ptp_clock_adjtime(struct posix_clock *pc, struct __kernel_timex *tx)
116 {
117         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
118         struct ptp_clock_info *ops;
119         int err = -EOPNOTSUPP;
120
121         ops = ptp->info;
122
123         if (tx->modes & ADJ_SETOFFSET) {
124                 struct timespec64 ts;
125                 ktime_t kt;
126                 s64 delta;
127
128                 ts.tv_sec  = tx->time.tv_sec;
129                 ts.tv_nsec = tx->time.tv_usec;
130
131                 if (!(tx->modes & ADJ_NANO))
132                         ts.tv_nsec *= 1000;
133
134                 if ((unsigned long) ts.tv_nsec >= NSEC_PER_SEC)
135                         return -EINVAL;
136
137                 kt = timespec64_to_ktime(ts);
138                 delta = ktime_to_ns(kt);
139                 err = ops->adjtime(ops, delta);
140         } else if (tx->modes & ADJ_FREQUENCY) {
141                 s32 ppb = scaled_ppm_to_ppb(tx->freq);
142                 if (ppb > ops->max_adj || ppb < -ops->max_adj)
143                         return -ERANGE;
144                 if (ops->adjfine)
145                         err = ops->adjfine(ops, tx->freq);
146                 else
147                         err = ops->adjfreq(ops, ppb);
148                 ptp->dialed_frequency = tx->freq;
149         } else if (tx->modes & ADJ_OFFSET) {
150                 if (ops->adjphase) {
151                         s32 offset = tx->offset;
152
153                         if (!(tx->modes & ADJ_NANO))
154                                 offset *= NSEC_PER_USEC;
155
156                         err = ops->adjphase(ops, offset);
157                 }
158         } else if (tx->modes == 0) {
159                 tx->freq = ptp->dialed_frequency;
160                 err = 0;
161         }
162
163         return err;
164 }
165
166 static struct posix_clock_operations ptp_clock_ops = {
167         .owner          = THIS_MODULE,
168         .clock_adjtime  = ptp_clock_adjtime,
169         .clock_gettime  = ptp_clock_gettime,
170         .clock_getres   = ptp_clock_getres,
171         .clock_settime  = ptp_clock_settime,
172         .ioctl          = ptp_ioctl,
173         .open           = ptp_open,
174         .poll           = ptp_poll,
175         .read           = ptp_read,
176 };
177
178 static void ptp_clock_release(struct device *dev)
179 {
180         struct ptp_clock *ptp = container_of(dev, struct ptp_clock, dev);
181
182         ptp_cleanup_pin_groups(ptp);
183         mutex_destroy(&ptp->tsevq_mux);
184         mutex_destroy(&ptp->pincfg_mux);
185         ida_simple_remove(&ptp_clocks_map, ptp->index);
186         kfree(ptp);
187 }
188
189 static void ptp_aux_kworker(struct kthread_work *work)
190 {
191         struct ptp_clock *ptp = container_of(work, struct ptp_clock,
192                                              aux_work.work);
193         struct ptp_clock_info *info = ptp->info;
194         long delay;
195
196         delay = info->do_aux_work(info);
197
198         if (delay >= 0)
199                 kthread_queue_delayed_work(ptp->kworker, &ptp->aux_work, delay);
200 }
201
202 /* public interface */
203
204 struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
205                                      struct device *parent)
206 {
207         struct ptp_clock *ptp;
208         int err = 0, index, major = MAJOR(ptp_devt);
209
210         if (info->n_alarm > PTP_MAX_ALARMS)
211                 return ERR_PTR(-EINVAL);
212
213         /* Initialize a clock structure. */
214         err = -ENOMEM;
215         ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL);
216         if (ptp == NULL)
217                 goto no_memory;
218
219         index = ida_simple_get(&ptp_clocks_map, 0, MINORMASK + 1, GFP_KERNEL);
220         if (index < 0) {
221                 err = index;
222                 goto no_slot;
223         }
224
225         ptp->clock.ops = ptp_clock_ops;
226         ptp->info = info;
227         ptp->devid = MKDEV(major, index);
228         ptp->index = index;
229         spin_lock_init(&ptp->tsevq.lock);
230         mutex_init(&ptp->tsevq_mux);
231         mutex_init(&ptp->pincfg_mux);
232         init_waitqueue_head(&ptp->tsev_wq);
233
234         if (ptp->info->do_aux_work) {
235                 kthread_init_delayed_work(&ptp->aux_work, ptp_aux_kworker);
236                 ptp->kworker = kthread_create_worker(0, "ptp%d", ptp->index);
237                 if (IS_ERR(ptp->kworker)) {
238                         err = PTR_ERR(ptp->kworker);
239                         pr_err("failed to create ptp aux_worker %d\n", err);
240                         goto kworker_err;
241                 }
242         }
243
244         err = ptp_populate_pin_groups(ptp);
245         if (err)
246                 goto no_pin_groups;
247
248         /* Register a new PPS source. */
249         if (info->pps) {
250                 struct pps_source_info pps;
251                 memset(&pps, 0, sizeof(pps));
252                 snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index);
253                 pps.mode = PTP_PPS_MODE;
254                 pps.owner = info->owner;
255                 ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS);
256                 if (IS_ERR(ptp->pps_source)) {
257                         err = PTR_ERR(ptp->pps_source);
258                         pr_err("failed to register pps source\n");
259                         goto no_pps;
260                 }
261         }
262
263         /* Initialize a new device of our class in our clock structure. */
264         device_initialize(&ptp->dev);
265         ptp->dev.devt = ptp->devid;
266         ptp->dev.class = ptp_class;
267         ptp->dev.parent = parent;
268         ptp->dev.groups = ptp->pin_attr_groups;
269         ptp->dev.release = ptp_clock_release;
270         dev_set_drvdata(&ptp->dev, ptp);
271         dev_set_name(&ptp->dev, "ptp%d", ptp->index);
272
273         /* Create a posix clock and link it to the device. */
274         err = posix_clock_register(&ptp->clock, &ptp->dev);
275         if (err) {
276                 pr_err("failed to create posix clock\n");
277                 goto no_clock;
278         }
279
280         return ptp;
281
282 no_clock:
283         if (ptp->pps_source)
284                 pps_unregister_source(ptp->pps_source);
285 no_pps:
286         ptp_cleanup_pin_groups(ptp);
287 no_pin_groups:
288         if (ptp->kworker)
289                 kthread_destroy_worker(ptp->kworker);
290 kworker_err:
291         mutex_destroy(&ptp->tsevq_mux);
292         mutex_destroy(&ptp->pincfg_mux);
293         ida_simple_remove(&ptp_clocks_map, index);
294 no_slot:
295         kfree(ptp);
296 no_memory:
297         return ERR_PTR(err);
298 }
299 EXPORT_SYMBOL(ptp_clock_register);
300
301 int ptp_clock_unregister(struct ptp_clock *ptp)
302 {
303         ptp->defunct = 1;
304         wake_up_interruptible(&ptp->tsev_wq);
305
306         if (ptp->kworker) {
307                 kthread_cancel_delayed_work_sync(&ptp->aux_work);
308                 kthread_destroy_worker(ptp->kworker);
309         }
310
311         /* Release the clock's resources. */
312         if (ptp->pps_source)
313                 pps_unregister_source(ptp->pps_source);
314
315         posix_clock_unregister(&ptp->clock);
316
317         return 0;
318 }
319 EXPORT_SYMBOL(ptp_clock_unregister);
320
321 void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
322 {
323         struct pps_event_time evt;
324
325         switch (event->type) {
326
327         case PTP_CLOCK_ALARM:
328                 break;
329
330         case PTP_CLOCK_EXTTS:
331                 enqueue_external_timestamp(&ptp->tsevq, event);
332                 wake_up_interruptible(&ptp->tsev_wq);
333                 break;
334
335         case PTP_CLOCK_PPS:
336                 pps_get_ts(&evt);
337                 pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL);
338                 break;
339
340         case PTP_CLOCK_PPSUSR:
341                 pps_event(ptp->pps_source, &event->pps_times,
342                           PTP_PPS_EVENT, NULL);
343                 break;
344         }
345 }
346 EXPORT_SYMBOL(ptp_clock_event);
347
348 int ptp_clock_index(struct ptp_clock *ptp)
349 {
350         return ptp->index;
351 }
352 EXPORT_SYMBOL(ptp_clock_index);
353
354 int ptp_find_pin(struct ptp_clock *ptp,
355                  enum ptp_pin_function func, unsigned int chan)
356 {
357         struct ptp_pin_desc *pin = NULL;
358         int i;
359
360         for (i = 0; i < ptp->info->n_pins; i++) {
361                 if (ptp->info->pin_config[i].func == func &&
362                     ptp->info->pin_config[i].chan == chan) {
363                         pin = &ptp->info->pin_config[i];
364                         break;
365                 }
366         }
367
368         return pin ? i : -1;
369 }
370 EXPORT_SYMBOL(ptp_find_pin);
371
372 int ptp_find_pin_unlocked(struct ptp_clock *ptp,
373                           enum ptp_pin_function func, unsigned int chan)
374 {
375         int result;
376
377         mutex_lock(&ptp->pincfg_mux);
378
379         result = ptp_find_pin(ptp, func, chan);
380
381         mutex_unlock(&ptp->pincfg_mux);
382
383         return result;
384 }
385 EXPORT_SYMBOL(ptp_find_pin_unlocked);
386
387 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay)
388 {
389         return kthread_mod_delayed_work(ptp->kworker, &ptp->aux_work, delay);
390 }
391 EXPORT_SYMBOL(ptp_schedule_worker);
392
393 void ptp_cancel_worker_sync(struct ptp_clock *ptp)
394 {
395         kthread_cancel_delayed_work_sync(&ptp->aux_work);
396 }
397 EXPORT_SYMBOL(ptp_cancel_worker_sync);
398
399 /* module operations */
400
401 static void __exit ptp_exit(void)
402 {
403         class_destroy(ptp_class);
404         unregister_chrdev_region(ptp_devt, MINORMASK + 1);
405         ida_destroy(&ptp_clocks_map);
406 }
407
408 static int __init ptp_init(void)
409 {
410         int err;
411
412         ptp_class = class_create(THIS_MODULE, "ptp");
413         if (IS_ERR(ptp_class)) {
414                 pr_err("ptp: failed to allocate class\n");
415                 return PTR_ERR(ptp_class);
416         }
417
418         err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp");
419         if (err < 0) {
420                 pr_err("ptp: failed to allocate device region\n");
421                 goto no_region;
422         }
423
424         ptp_class->dev_groups = ptp_groups;
425         pr_info("PTP clock support registered\n");
426         return 0;
427
428 no_region:
429         class_destroy(ptp_class);
430         return err;
431 }
432
433 subsys_initcall(ptp_init);
434 module_exit(ptp_exit);
435
436 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
437 MODULE_DESCRIPTION("PTP clocks support");
438 MODULE_LICENSE("GPL");