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Richard Cochrand94ba802011-04-22 12:03:08 +02001/*
2 * PTP 1588 clock support
3 *
4 * Copyright (C) 2010 OMICRON electronics GmbH
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
Jiri Benc7356a762013-04-12 00:56:15 +000020#include <linux/idr.h>
Richard Cochrand94ba802011-04-22 12:03:08 +020021#include <linux/device.h>
22#include <linux/err.h>
23#include <linux/init.h>
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/posix-clock.h>
27#include <linux/pps_kernel.h>
28#include <linux/slab.h>
29#include <linux/syscalls.h>
30#include <linux/uaccess.h>
31
32#include "ptp_private.h"
33
34#define PTP_MAX_ALARMS 4
Richard Cochrand94ba802011-04-22 12:03:08 +020035#define PTP_PPS_DEFAULTS (PPS_CAPTUREASSERT | PPS_OFFSETASSERT)
36#define PTP_PPS_EVENT PPS_CAPTUREASSERT
37#define PTP_PPS_MODE (PTP_PPS_DEFAULTS | PPS_CANWAIT | PPS_TSFMT_TSPEC)
38
39/* private globals */
40
41static dev_t ptp_devt;
42static struct class *ptp_class;
43
Jiri Benc7356a762013-04-12 00:56:15 +000044static DEFINE_IDA(ptp_clocks_map);
Richard Cochrand94ba802011-04-22 12:03:08 +020045
46/* time stamp event queue operations */
47
48static inline int queue_free(struct timestamp_event_queue *q)
49{
50 return PTP_MAX_TIMESTAMPS - queue_cnt(q) - 1;
51}
52
53static void enqueue_external_timestamp(struct timestamp_event_queue *queue,
54 struct ptp_clock_event *src)
55{
56 struct ptp_extts_event *dst;
57 unsigned long flags;
58 s64 seconds;
59 u32 remainder;
60
61 seconds = div_u64_rem(src->timestamp, 1000000000, &remainder);
62
63 spin_lock_irqsave(&queue->lock, flags);
64
65 dst = &queue->buf[queue->tail];
66 dst->index = src->index;
67 dst->t.sec = seconds;
68 dst->t.nsec = remainder;
69
70 if (!queue_free(queue))
71 queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
72
73 queue->tail = (queue->tail + 1) % PTP_MAX_TIMESTAMPS;
74
75 spin_unlock_irqrestore(&queue->lock, flags);
76}
77
78static s32 scaled_ppm_to_ppb(long ppm)
79{
80 /*
81 * The 'freq' field in the 'struct timex' is in parts per
82 * million, but with a 16 bit binary fractional field.
83 *
84 * We want to calculate
85 *
86 * ppb = scaled_ppm * 1000 / 2^16
87 *
88 * which simplifies to
89 *
90 * ppb = scaled_ppm * 125 / 2^13
91 */
92 s64 ppb = 1 + ppm;
93 ppb *= 125;
94 ppb >>= 13;
95 return (s32) ppb;
96}
97
98/* posix clock implementation */
99
100static int ptp_clock_getres(struct posix_clock *pc, struct timespec *tp)
101{
Thomas Gleixnerd68fb112011-12-05 21:16:06 +0100102 tp->tv_sec = 0;
103 tp->tv_nsec = 1;
104 return 0;
Richard Cochrand94ba802011-04-22 12:03:08 +0200105}
106
107static int ptp_clock_settime(struct posix_clock *pc, const struct timespec *tp)
108{
109 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
Richard Cochrand7d38f52015-03-29 23:11:53 +0200110 struct timespec64 ts = timespec_to_timespec64(*tp);
111
Richard Cochraned7c6312015-03-29 23:12:13 +0200112 return ptp->info->settime64(ptp->info, &ts);
Richard Cochrand94ba802011-04-22 12:03:08 +0200113}
114
115static int ptp_clock_gettime(struct posix_clock *pc, struct timespec *tp)
116{
117 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
Richard Cochrand7d38f52015-03-29 23:11:53 +0200118 struct timespec64 ts;
119 int err;
120
Richard Cochraned7c6312015-03-29 23:12:13 +0200121 err = ptp->info->gettime64(ptp->info, &ts);
122 if (!err)
123 *tp = timespec64_to_timespec(ts);
Richard Cochrand7d38f52015-03-29 23:11:53 +0200124 return err;
Richard Cochrand94ba802011-04-22 12:03:08 +0200125}
126
127static int ptp_clock_adjtime(struct posix_clock *pc, struct timex *tx)
128{
129 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
130 struct ptp_clock_info *ops;
131 int err = -EOPNOTSUPP;
132
133 ops = ptp->info;
134
135 if (tx->modes & ADJ_SETOFFSET) {
136 struct timespec ts;
137 ktime_t kt;
138 s64 delta;
139
140 ts.tv_sec = tx->time.tv_sec;
141 ts.tv_nsec = tx->time.tv_usec;
142
143 if (!(tx->modes & ADJ_NANO))
144 ts.tv_nsec *= 1000;
145
146 if ((unsigned long) ts.tv_nsec >= NSEC_PER_SEC)
147 return -EINVAL;
148
149 kt = timespec_to_ktime(ts);
150 delta = ktime_to_ns(kt);
151 err = ops->adjtime(ops, delta);
Richard Cochrand94ba802011-04-22 12:03:08 +0200152 } else if (tx->modes & ADJ_FREQUENCY) {
Richard Cochrand39a7432014-04-27 15:01:27 +0200153 s32 ppb = scaled_ppm_to_ppb(tx->freq);
154 if (ppb > ops->max_adj || ppb < -ops->max_adj)
155 return -ERANGE;
156 err = ops->adjfreq(ops, ppb);
Richard Cochran39a8cbd2012-09-22 07:02:01 +0000157 ptp->dialed_frequency = tx->freq;
Richard Cochran5c35bad2012-09-22 07:02:02 +0000158 } else if (tx->modes == 0) {
159 tx->freq = ptp->dialed_frequency;
160 err = 0;
Richard Cochrand94ba802011-04-22 12:03:08 +0200161 }
162
163 return err;
164}
165
166static 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
178static void delete_ptp_clock(struct posix_clock *pc)
179{
180 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
181
182 mutex_destroy(&ptp->tsevq_mux);
Richard Cochran60923152014-03-20 22:21:52 +0100183 mutex_destroy(&ptp->pincfg_mux);
Jiri Benc7356a762013-04-12 00:56:15 +0000184 ida_simple_remove(&ptp_clocks_map, ptp->index);
Richard Cochrand94ba802011-04-22 12:03:08 +0200185 kfree(ptp);
186}
187
188/* public interface */
189
Richard Cochran1ef76152012-09-22 07:02:03 +0000190struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
191 struct device *parent)
Richard Cochrand94ba802011-04-22 12:03:08 +0200192{
193 struct ptp_clock *ptp;
194 int err = 0, index, major = MAJOR(ptp_devt);
195
196 if (info->n_alarm > PTP_MAX_ALARMS)
197 return ERR_PTR(-EINVAL);
198
Richard Cochrand94ba802011-04-22 12:03:08 +0200199 /* Initialize a clock structure. */
200 err = -ENOMEM;
201 ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL);
202 if (ptp == NULL)
203 goto no_memory;
204
Jiri Benc7356a762013-04-12 00:56:15 +0000205 index = ida_simple_get(&ptp_clocks_map, 0, MINORMASK + 1, GFP_KERNEL);
206 if (index < 0) {
207 err = index;
208 goto no_slot;
209 }
210
Richard Cochrand94ba802011-04-22 12:03:08 +0200211 ptp->clock.ops = ptp_clock_ops;
212 ptp->clock.release = delete_ptp_clock;
213 ptp->info = info;
214 ptp->devid = MKDEV(major, index);
215 ptp->index = index;
216 spin_lock_init(&ptp->tsevq.lock);
217 mutex_init(&ptp->tsevq_mux);
Richard Cochran60923152014-03-20 22:21:52 +0100218 mutex_init(&ptp->pincfg_mux);
Richard Cochrand94ba802011-04-22 12:03:08 +0200219 init_waitqueue_head(&ptp->tsev_wq);
220
221 /* Create a new device in our class. */
Richard Cochran1ef76152012-09-22 07:02:03 +0000222 ptp->dev = device_create(ptp_class, parent, ptp->devid, ptp,
Richard Cochrand94ba802011-04-22 12:03:08 +0200223 "ptp%d", ptp->index);
224 if (IS_ERR(ptp->dev))
225 goto no_device;
226
227 dev_set_drvdata(ptp->dev, ptp);
228
229 err = ptp_populate_sysfs(ptp);
230 if (err)
231 goto no_sysfs;
232
233 /* Register a new PPS source. */
234 if (info->pps) {
235 struct pps_source_info pps;
236 memset(&pps, 0, sizeof(pps));
237 snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index);
238 pps.mode = PTP_PPS_MODE;
239 pps.owner = info->owner;
240 ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS);
241 if (!ptp->pps_source) {
242 pr_err("failed to register pps source\n");
243 goto no_pps;
244 }
245 }
246
247 /* Create a posix clock. */
248 err = posix_clock_register(&ptp->clock, ptp->devid);
249 if (err) {
250 pr_err("failed to create posix clock\n");
251 goto no_clock;
252 }
253
Richard Cochrand94ba802011-04-22 12:03:08 +0200254 return ptp;
255
256no_clock:
257 if (ptp->pps_source)
258 pps_unregister_source(ptp->pps_source);
259no_pps:
260 ptp_cleanup_sysfs(ptp);
261no_sysfs:
262 device_destroy(ptp_class, ptp->devid);
263no_device:
264 mutex_destroy(&ptp->tsevq_mux);
Richard Cochran60923152014-03-20 22:21:52 +0100265 mutex_destroy(&ptp->pincfg_mux);
Christophe Jailletb9118b72016-10-02 09:04:16 +0200266 ida_simple_remove(&ptp_clocks_map, index);
Jiri Benc7356a762013-04-12 00:56:15 +0000267no_slot:
Richard Cochrand94ba802011-04-22 12:03:08 +0200268 kfree(ptp);
269no_memory:
Richard Cochrand94ba802011-04-22 12:03:08 +0200270 return ERR_PTR(err);
271}
272EXPORT_SYMBOL(ptp_clock_register);
273
274int ptp_clock_unregister(struct ptp_clock *ptp)
275{
276 ptp->defunct = 1;
277 wake_up_interruptible(&ptp->tsev_wq);
278
279 /* Release the clock's resources. */
280 if (ptp->pps_source)
281 pps_unregister_source(ptp->pps_source);
282 ptp_cleanup_sysfs(ptp);
283 device_destroy(ptp_class, ptp->devid);
284
285 posix_clock_unregister(&ptp->clock);
286 return 0;
287}
288EXPORT_SYMBOL(ptp_clock_unregister);
289
290void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
291{
292 struct pps_event_time evt;
293
294 switch (event->type) {
295
296 case PTP_CLOCK_ALARM:
297 break;
298
299 case PTP_CLOCK_EXTTS:
300 enqueue_external_timestamp(&ptp->tsevq, event);
301 wake_up_interruptible(&ptp->tsev_wq);
302 break;
303
304 case PTP_CLOCK_PPS:
305 pps_get_ts(&evt);
306 pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL);
307 break;
Ben Hutchings220a60a2012-09-03 11:34:58 +0100308
309 case PTP_CLOCK_PPSUSR:
310 pps_event(ptp->pps_source, &event->pps_times,
311 PTP_PPS_EVENT, NULL);
312 break;
Richard Cochrand94ba802011-04-22 12:03:08 +0200313 }
314}
315EXPORT_SYMBOL(ptp_clock_event);
316
Richard Cochran995a9092012-04-03 22:59:16 +0000317int ptp_clock_index(struct ptp_clock *ptp)
318{
319 return ptp->index;
320}
321EXPORT_SYMBOL(ptp_clock_index);
322
Richard Cochran60923152014-03-20 22:21:52 +0100323int ptp_find_pin(struct ptp_clock *ptp,
324 enum ptp_pin_function func, unsigned int chan)
325{
326 struct ptp_pin_desc *pin = NULL;
327 int i;
328
329 mutex_lock(&ptp->pincfg_mux);
330 for (i = 0; i < ptp->info->n_pins; i++) {
331 if (ptp->info->pin_config[i].func == func &&
332 ptp->info->pin_config[i].chan == chan) {
333 pin = &ptp->info->pin_config[i];
334 break;
335 }
336 }
337 mutex_unlock(&ptp->pincfg_mux);
338
339 return pin ? i : -1;
340}
341EXPORT_SYMBOL(ptp_find_pin);
342
Richard Cochrand94ba802011-04-22 12:03:08 +0200343/* module operations */
344
345static void __exit ptp_exit(void)
346{
347 class_destroy(ptp_class);
Jiri Benc7356a762013-04-12 00:56:15 +0000348 unregister_chrdev_region(ptp_devt, MINORMASK + 1);
349 ida_destroy(&ptp_clocks_map);
Richard Cochrand94ba802011-04-22 12:03:08 +0200350}
351
352static int __init ptp_init(void)
353{
354 int err;
355
356 ptp_class = class_create(THIS_MODULE, "ptp");
357 if (IS_ERR(ptp_class)) {
358 pr_err("ptp: failed to allocate class\n");
359 return PTR_ERR(ptp_class);
360 }
361
Jiri Benc7356a762013-04-12 00:56:15 +0000362 err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp");
Richard Cochrand94ba802011-04-22 12:03:08 +0200363 if (err < 0) {
364 pr_err("ptp: failed to allocate device region\n");
365 goto no_region;
366 }
367
Greg Kroah-Hartman34991162013-07-24 15:05:20 -0700368 ptp_class->dev_groups = ptp_groups;
Richard Cochrand94ba802011-04-22 12:03:08 +0200369 pr_info("PTP clock support registered\n");
370 return 0;
371
372no_region:
373 class_destroy(ptp_class);
374 return err;
375}
376
377subsys_initcall(ptp_init);
378module_exit(ptp_exit);
379
Richard Cochranc2ec3ff2012-03-16 22:39:29 +0000380MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
Richard Cochrand94ba802011-04-22 12:03:08 +0200381MODULE_DESCRIPTION("PTP clocks support");
382MODULE_LICENSE("GPL");