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1/*
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 */
20#include <linux/idr.h>
21#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
35#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
44static DEFINE_IDA(ptp_clocks_map);
45
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{
102 tp->tv_sec = 0;
103 tp->tv_nsec = 1;
104 return 0;
105}
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);
110 return ptp->info->settime(ptp->info, tp);
111}
112
113static int ptp_clock_gettime(struct posix_clock *pc, struct timespec *tp)
114{
115 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
116 return ptp->info->gettime(ptp->info, tp);
117}
118
119static int ptp_clock_adjtime(struct posix_clock *pc, struct timex *tx)
120{
121 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
122 struct ptp_clock_info *ops;
123 int err = -EOPNOTSUPP;
124
125 ops = ptp->info;
126
127 if (tx->modes & ADJ_SETOFFSET) {
128 struct timespec ts;
129 ktime_t kt;
130 s64 delta;
131
132 ts.tv_sec = tx->time.tv_sec;
133 ts.tv_nsec = tx->time.tv_usec;
134
135 if (!(tx->modes & ADJ_NANO))
136 ts.tv_nsec *= 1000;
137
138 if ((unsigned long) ts.tv_nsec >= NSEC_PER_SEC)
139 return -EINVAL;
140
141 kt = timespec_to_ktime(ts);
142 delta = ktime_to_ns(kt);
143 err = ops->adjtime(ops, delta);
144 } else if (tx->modes & ADJ_FREQUENCY) {
145 err = ops->adjfreq(ops, scaled_ppm_to_ppb(tx->freq));
146 ptp->dialed_frequency = tx->freq;
147 } else if (tx->modes == 0) {
148 tx->freq = ptp->dialed_frequency;
149 err = 0;
150 }
151
152 return err;
153}
154
155static struct posix_clock_operations ptp_clock_ops = {
156 .owner = THIS_MODULE,
157 .clock_adjtime = ptp_clock_adjtime,
158 .clock_gettime = ptp_clock_gettime,
159 .clock_getres = ptp_clock_getres,
160 .clock_settime = ptp_clock_settime,
161 .ioctl = ptp_ioctl,
162 .open = ptp_open,
163 .poll = ptp_poll,
164 .read = ptp_read,
165};
166
167static void delete_ptp_clock(struct posix_clock *pc)
168{
169 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
170
171 mutex_destroy(&ptp->tsevq_mux);
172 mutex_destroy(&ptp->pincfg_mux);
173 ida_simple_remove(&ptp_clocks_map, ptp->index);
174 kfree(ptp);
175}
176
177/* public interface */
178
179struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
180 struct device *parent)
181{
182 struct ptp_clock *ptp;
183 int err = 0, index, major = MAJOR(ptp_devt);
184
185 if (info->n_alarm > PTP_MAX_ALARMS)
186 return ERR_PTR(-EINVAL);
187
188 /* Initialize a clock structure. */
189 err = -ENOMEM;
190 ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL);
191 if (ptp == NULL)
192 goto no_memory;
193
194 index = ida_simple_get(&ptp_clocks_map, 0, MINORMASK + 1, GFP_KERNEL);
195 if (index < 0) {
196 err = index;
197 goto no_slot;
198 }
199
200 ptp->clock.ops = ptp_clock_ops;
201 ptp->clock.release = delete_ptp_clock;
202 ptp->info = info;
203 ptp->devid = MKDEV(major, index);
204 ptp->index = index;
205 spin_lock_init(&ptp->tsevq.lock);
206 mutex_init(&ptp->tsevq_mux);
207 mutex_init(&ptp->pincfg_mux);
208 init_waitqueue_head(&ptp->tsev_wq);
209
210 /* Create a new device in our class. */
211 ptp->dev = device_create(ptp_class, parent, ptp->devid, ptp,
212 "ptp%d", ptp->index);
213 if (IS_ERR(ptp->dev))
214 goto no_device;
215
216 dev_set_drvdata(ptp->dev, ptp);
217
218 err = ptp_populate_sysfs(ptp);
219 if (err)
220 goto no_sysfs;
221
222 /* Register a new PPS source. */
223 if (info->pps) {
224 struct pps_source_info pps;
225 memset(&pps, 0, sizeof(pps));
226 snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index);
227 pps.mode = PTP_PPS_MODE;
228 pps.owner = info->owner;
229 ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS);
230 if (!ptp->pps_source) {
231 pr_err("failed to register pps source\n");
232 goto no_pps;
233 }
234 }
235
236 /* Create a posix clock. */
237 err = posix_clock_register(&ptp->clock, ptp->devid);
238 if (err) {
239 pr_err("failed to create posix clock\n");
240 goto no_clock;
241 }
242
243 return ptp;
244
245no_clock:
246 if (ptp->pps_source)
247 pps_unregister_source(ptp->pps_source);
248no_pps:
249 ptp_cleanup_sysfs(ptp);
250no_sysfs:
251 device_destroy(ptp_class, ptp->devid);
252no_device:
253 mutex_destroy(&ptp->tsevq_mux);
254 mutex_destroy(&ptp->pincfg_mux);
255no_slot:
256 kfree(ptp);
257no_memory:
258 return ERR_PTR(err);
259}
260EXPORT_SYMBOL(ptp_clock_register);
261
262int ptp_clock_unregister(struct ptp_clock *ptp)
263{
264 ptp->defunct = 1;
265 wake_up_interruptible(&ptp->tsev_wq);
266
267 /* Release the clock's resources. */
268 if (ptp->pps_source)
269 pps_unregister_source(ptp->pps_source);
270 ptp_cleanup_sysfs(ptp);
271 device_destroy(ptp_class, ptp->devid);
272
273 posix_clock_unregister(&ptp->clock);
274 return 0;
275}
276EXPORT_SYMBOL(ptp_clock_unregister);
277
278void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
279{
280 struct pps_event_time evt;
281
282 switch (event->type) {
283
284 case PTP_CLOCK_ALARM:
285 break;
286
287 case PTP_CLOCK_EXTTS:
288 enqueue_external_timestamp(&ptp->tsevq, event);
289 wake_up_interruptible(&ptp->tsev_wq);
290 break;
291
292 case PTP_CLOCK_PPS:
293 pps_get_ts(&evt);
294 pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL);
295 break;
296
297 case PTP_CLOCK_PPSUSR:
298 pps_event(ptp->pps_source, &event->pps_times,
299 PTP_PPS_EVENT, NULL);
300 break;
301 }
302}
303EXPORT_SYMBOL(ptp_clock_event);
304
305int ptp_clock_index(struct ptp_clock *ptp)
306{
307 return ptp->index;
308}
309EXPORT_SYMBOL(ptp_clock_index);
310
311int ptp_find_pin(struct ptp_clock *ptp,
312 enum ptp_pin_function func, unsigned int chan)
313{
314 struct ptp_pin_desc *pin = NULL;
315 int i;
316
317 mutex_lock(&ptp->pincfg_mux);
318 for (i = 0; i < ptp->info->n_pins; i++) {
319 if (ptp->info->pin_config[i].func == func &&
320 ptp->info->pin_config[i].chan == chan) {
321 pin = &ptp->info->pin_config[i];
322 break;
323 }
324 }
325 mutex_unlock(&ptp->pincfg_mux);
326
327 return pin ? i : -1;
328}
329EXPORT_SYMBOL(ptp_find_pin);
330
331/* module operations */
332
333static void __exit ptp_exit(void)
334{
335 class_destroy(ptp_class);
336 unregister_chrdev_region(ptp_devt, MINORMASK + 1);
337 ida_destroy(&ptp_clocks_map);
338}
339
340static int __init ptp_init(void)
341{
342 int err;
343
344 ptp_class = class_create(THIS_MODULE, "ptp");
345 if (IS_ERR(ptp_class)) {
346 pr_err("ptp: failed to allocate class\n");
347 return PTR_ERR(ptp_class);
348 }
349
350 err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp");
351 if (err < 0) {
352 pr_err("ptp: failed to allocate device region\n");
353 goto no_region;
354 }
355
356 ptp_class->dev_groups = ptp_groups;
357 pr_info("PTP clock support registered\n");
358 return 0;
359
360no_region:
361 class_destroy(ptp_class);
362 return err;
363}
364
365subsys_initcall(ptp_init);
366module_exit(ptp_exit);
367
368MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
369MODULE_DESCRIPTION("PTP clocks support");
370MODULE_LICENSE("GPL");
1/*
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 */
20#include <linux/bitops.h>
21#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
35#define PTP_MAX_CLOCKS 8
36#define PTP_PPS_DEFAULTS (PPS_CAPTUREASSERT | PPS_OFFSETASSERT)
37#define PTP_PPS_EVENT PPS_CAPTUREASSERT
38#define PTP_PPS_MODE (PTP_PPS_DEFAULTS | PPS_CANWAIT | PPS_TSFMT_TSPEC)
39
40/* private globals */
41
42static dev_t ptp_devt;
43static struct class *ptp_class;
44
45static DECLARE_BITMAP(ptp_clocks_map, PTP_MAX_CLOCKS);
46static DEFINE_MUTEX(ptp_clocks_mutex); /* protects 'ptp_clocks_map' */
47
48/* time stamp event queue operations */
49
50static inline int queue_free(struct timestamp_event_queue *q)
51{
52 return PTP_MAX_TIMESTAMPS - queue_cnt(q) - 1;
53}
54
55static void enqueue_external_timestamp(struct timestamp_event_queue *queue,
56 struct ptp_clock_event *src)
57{
58 struct ptp_extts_event *dst;
59 unsigned long flags;
60 s64 seconds;
61 u32 remainder;
62
63 seconds = div_u64_rem(src->timestamp, 1000000000, &remainder);
64
65 spin_lock_irqsave(&queue->lock, flags);
66
67 dst = &queue->buf[queue->tail];
68 dst->index = src->index;
69 dst->t.sec = seconds;
70 dst->t.nsec = remainder;
71
72 if (!queue_free(queue))
73 queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
74
75 queue->tail = (queue->tail + 1) % PTP_MAX_TIMESTAMPS;
76
77 spin_unlock_irqrestore(&queue->lock, flags);
78}
79
80static s32 scaled_ppm_to_ppb(long ppm)
81{
82 /*
83 * The 'freq' field in the 'struct timex' is in parts per
84 * million, but with a 16 bit binary fractional field.
85 *
86 * We want to calculate
87 *
88 * ppb = scaled_ppm * 1000 / 2^16
89 *
90 * which simplifies to
91 *
92 * ppb = scaled_ppm * 125 / 2^13
93 */
94 s64 ppb = 1 + ppm;
95 ppb *= 125;
96 ppb >>= 13;
97 return (s32) ppb;
98}
99
100/* posix clock implementation */
101
102static int ptp_clock_getres(struct posix_clock *pc, struct timespec *tp)
103{
104 tp->tv_sec = 0;
105 tp->tv_nsec = 1;
106 return 0;
107}
108
109static int ptp_clock_settime(struct posix_clock *pc, const struct timespec *tp)
110{
111 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
112 return ptp->info->settime(ptp->info, tp);
113}
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);
118 return ptp->info->gettime(ptp->info, tp);
119}
120
121static int ptp_clock_adjtime(struct posix_clock *pc, struct timex *tx)
122{
123 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
124 struct ptp_clock_info *ops;
125 int err = -EOPNOTSUPP;
126
127 ops = ptp->info;
128
129 if (tx->modes & ADJ_SETOFFSET) {
130 struct timespec ts;
131 ktime_t kt;
132 s64 delta;
133
134 ts.tv_sec = tx->time.tv_sec;
135 ts.tv_nsec = tx->time.tv_usec;
136
137 if (!(tx->modes & ADJ_NANO))
138 ts.tv_nsec *= 1000;
139
140 if ((unsigned long) ts.tv_nsec >= NSEC_PER_SEC)
141 return -EINVAL;
142
143 kt = timespec_to_ktime(ts);
144 delta = ktime_to_ns(kt);
145 err = ops->adjtime(ops, delta);
146
147 } else if (tx->modes & ADJ_FREQUENCY) {
148
149 err = ops->adjfreq(ops, scaled_ppm_to_ppb(tx->freq));
150 }
151
152 return err;
153}
154
155static struct posix_clock_operations ptp_clock_ops = {
156 .owner = THIS_MODULE,
157 .clock_adjtime = ptp_clock_adjtime,
158 .clock_gettime = ptp_clock_gettime,
159 .clock_getres = ptp_clock_getres,
160 .clock_settime = ptp_clock_settime,
161 .ioctl = ptp_ioctl,
162 .open = ptp_open,
163 .poll = ptp_poll,
164 .read = ptp_read,
165};
166
167static void delete_ptp_clock(struct posix_clock *pc)
168{
169 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
170
171 mutex_destroy(&ptp->tsevq_mux);
172
173 /* Remove the clock from the bit map. */
174 mutex_lock(&ptp_clocks_mutex);
175 clear_bit(ptp->index, ptp_clocks_map);
176 mutex_unlock(&ptp_clocks_mutex);
177
178 kfree(ptp);
179}
180
181/* public interface */
182
183struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info)
184{
185 struct ptp_clock *ptp;
186 int err = 0, index, major = MAJOR(ptp_devt);
187
188 if (info->n_alarm > PTP_MAX_ALARMS)
189 return ERR_PTR(-EINVAL);
190
191 /* Find a free clock slot and reserve it. */
192 err = -EBUSY;
193 mutex_lock(&ptp_clocks_mutex);
194 index = find_first_zero_bit(ptp_clocks_map, PTP_MAX_CLOCKS);
195 if (index < PTP_MAX_CLOCKS)
196 set_bit(index, ptp_clocks_map);
197 else
198 goto no_slot;
199
200 /* Initialize a clock structure. */
201 err = -ENOMEM;
202 ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL);
203 if (ptp == NULL)
204 goto no_memory;
205
206 ptp->clock.ops = ptp_clock_ops;
207 ptp->clock.release = delete_ptp_clock;
208 ptp->info = info;
209 ptp->devid = MKDEV(major, index);
210 ptp->index = index;
211 spin_lock_init(&ptp->tsevq.lock);
212 mutex_init(&ptp->tsevq_mux);
213 init_waitqueue_head(&ptp->tsev_wq);
214
215 /* Create a new device in our class. */
216 ptp->dev = device_create(ptp_class, NULL, ptp->devid, ptp,
217 "ptp%d", ptp->index);
218 if (IS_ERR(ptp->dev))
219 goto no_device;
220
221 dev_set_drvdata(ptp->dev, ptp);
222
223 err = ptp_populate_sysfs(ptp);
224 if (err)
225 goto no_sysfs;
226
227 /* Register a new PPS source. */
228 if (info->pps) {
229 struct pps_source_info pps;
230 memset(&pps, 0, sizeof(pps));
231 snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index);
232 pps.mode = PTP_PPS_MODE;
233 pps.owner = info->owner;
234 ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS);
235 if (!ptp->pps_source) {
236 pr_err("failed to register pps source\n");
237 goto no_pps;
238 }
239 }
240
241 /* Create a posix clock. */
242 err = posix_clock_register(&ptp->clock, ptp->devid);
243 if (err) {
244 pr_err("failed to create posix clock\n");
245 goto no_clock;
246 }
247
248 mutex_unlock(&ptp_clocks_mutex);
249 return ptp;
250
251no_clock:
252 if (ptp->pps_source)
253 pps_unregister_source(ptp->pps_source);
254no_pps:
255 ptp_cleanup_sysfs(ptp);
256no_sysfs:
257 device_destroy(ptp_class, ptp->devid);
258no_device:
259 mutex_destroy(&ptp->tsevq_mux);
260 kfree(ptp);
261no_memory:
262 clear_bit(index, ptp_clocks_map);
263no_slot:
264 mutex_unlock(&ptp_clocks_mutex);
265 return ERR_PTR(err);
266}
267EXPORT_SYMBOL(ptp_clock_register);
268
269int ptp_clock_unregister(struct ptp_clock *ptp)
270{
271 ptp->defunct = 1;
272 wake_up_interruptible(&ptp->tsev_wq);
273
274 /* Release the clock's resources. */
275 if (ptp->pps_source)
276 pps_unregister_source(ptp->pps_source);
277 ptp_cleanup_sysfs(ptp);
278 device_destroy(ptp_class, ptp->devid);
279
280 posix_clock_unregister(&ptp->clock);
281 return 0;
282}
283EXPORT_SYMBOL(ptp_clock_unregister);
284
285void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
286{
287 struct pps_event_time evt;
288
289 switch (event->type) {
290
291 case PTP_CLOCK_ALARM:
292 break;
293
294 case PTP_CLOCK_EXTTS:
295 enqueue_external_timestamp(&ptp->tsevq, event);
296 wake_up_interruptible(&ptp->tsev_wq);
297 break;
298
299 case PTP_CLOCK_PPS:
300 pps_get_ts(&evt);
301 pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL);
302 break;
303 }
304}
305EXPORT_SYMBOL(ptp_clock_event);
306
307int ptp_clock_index(struct ptp_clock *ptp)
308{
309 return ptp->index;
310}
311EXPORT_SYMBOL(ptp_clock_index);
312
313/* module operations */
314
315static void __exit ptp_exit(void)
316{
317 class_destroy(ptp_class);
318 unregister_chrdev_region(ptp_devt, PTP_MAX_CLOCKS);
319}
320
321static int __init ptp_init(void)
322{
323 int err;
324
325 ptp_class = class_create(THIS_MODULE, "ptp");
326 if (IS_ERR(ptp_class)) {
327 pr_err("ptp: failed to allocate class\n");
328 return PTR_ERR(ptp_class);
329 }
330
331 err = alloc_chrdev_region(&ptp_devt, 0, PTP_MAX_CLOCKS, "ptp");
332 if (err < 0) {
333 pr_err("ptp: failed to allocate device region\n");
334 goto no_region;
335 }
336
337 ptp_class->dev_attrs = ptp_dev_attrs;
338 pr_info("PTP clock support registered\n");
339 return 0;
340
341no_region:
342 class_destroy(ptp_class);
343 return err;
344}
345
346subsys_initcall(ptp_init);
347module_exit(ptp_exit);
348
349MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
350MODULE_DESCRIPTION("PTP clocks support");
351MODULE_LICENSE("GPL");