1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
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
40
41static dev_t ptp_devt;
42static struct class *ptp_class;
43
44static DEFINE_IDA(ptp_clocks_map);
45
46
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
82
83
84
85
86
87
88
89
90
91
92 s64 ppb = 1 + ppm;
93 ppb *= 125;
94 ppb >>= 13;
95 return (s32) ppb;
96}
97
98
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 ida_simple_remove(&ptp_clocks_map, ptp->index);
173 kfree(ptp);
174}
175
176
177
178struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
179 struct device *parent)
180{
181 struct ptp_clock *ptp;
182 int err = 0, index, major = MAJOR(ptp_devt);
183
184 if (info->n_alarm > PTP_MAX_ALARMS)
185 return ERR_PTR(-EINVAL);
186
187
188 err = -ENOMEM;
189 ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL);
190 if (ptp == NULL)
191 goto no_memory;
192
193 index = ida_simple_get(&ptp_clocks_map, 0, MINORMASK + 1, GFP_KERNEL);
194 if (index < 0) {
195 err = index;
196 goto no_slot;
197 }
198
199 ptp->clock.ops = ptp_clock_ops;
200 ptp->clock.release = delete_ptp_clock;
201 ptp->info = info;
202 ptp->devid = MKDEV(major, index);
203 ptp->index = index;
204 spin_lock_init(&ptp->tsevq.lock);
205 mutex_init(&ptp->tsevq_mux);
206 init_waitqueue_head(&ptp->tsev_wq);
207
208
209 ptp->dev = device_create(ptp_class, parent, ptp->devid, ptp,
210 "ptp%d", ptp->index);
211 if (IS_ERR(ptp->dev))
212 goto no_device;
213
214 dev_set_drvdata(ptp->dev, ptp);
215
216 err = ptp_populate_sysfs(ptp);
217 if (err)
218 goto no_sysfs;
219
220
221 if (info->pps) {
222 struct pps_source_info pps;
223 memset(&pps, 0, sizeof(pps));
224 snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index);
225 pps.mode = PTP_PPS_MODE;
226 pps.owner = info->owner;
227 ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS);
228 if (!ptp->pps_source) {
229 pr_err("failed to register pps source\n");
230 goto no_pps;
231 }
232 }
233
234
235 err = posix_clock_register(&ptp->clock, ptp->devid);
236 if (err) {
237 pr_err("failed to create posix clock\n");
238 goto no_clock;
239 }
240
241 return ptp;
242
243no_clock:
244 if (ptp->pps_source)
245 pps_unregister_source(ptp->pps_source);
246no_pps:
247 ptp_cleanup_sysfs(ptp);
248no_sysfs:
249 device_destroy(ptp_class, ptp->devid);
250no_device:
251 mutex_destroy(&ptp->tsevq_mux);
252no_slot:
253 kfree(ptp);
254no_memory:
255 return ERR_PTR(err);
256}
257EXPORT_SYMBOL(ptp_clock_register);
258
259int ptp_clock_unregister(struct ptp_clock *ptp)
260{
261 ptp->defunct = 1;
262 wake_up_interruptible(&ptp->tsev_wq);
263
264
265 if (ptp->pps_source)
266 pps_unregister_source(ptp->pps_source);
267 ptp_cleanup_sysfs(ptp);
268 device_destroy(ptp_class, ptp->devid);
269
270 posix_clock_unregister(&ptp->clock);
271 return 0;
272}
273EXPORT_SYMBOL(ptp_clock_unregister);
274
275void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
276{
277 struct pps_event_time evt;
278
279 switch (event->type) {
280
281 case PTP_CLOCK_ALARM:
282 break;
283
284 case PTP_CLOCK_EXTTS:
285 enqueue_external_timestamp(&ptp->tsevq, event);
286 wake_up_interruptible(&ptp->tsev_wq);
287 break;
288
289 case PTP_CLOCK_PPS:
290 pps_get_ts(&evt);
291 pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL);
292 break;
293
294 case PTP_CLOCK_PPSUSR:
295 pps_event(ptp->pps_source, &event->pps_times,
296 PTP_PPS_EVENT, NULL);
297 break;
298 }
299}
300EXPORT_SYMBOL(ptp_clock_event);
301
302int ptp_clock_index(struct ptp_clock *ptp)
303{
304 return ptp->index;
305}
306EXPORT_SYMBOL(ptp_clock_index);
307
308
309
310static void __exit ptp_exit(void)
311{
312 class_destroy(ptp_class);
313 unregister_chrdev_region(ptp_devt, MINORMASK + 1);
314 ida_destroy(&ptp_clocks_map);
315}
316
317static int __init ptp_init(void)
318{
319 int err;
320
321 ptp_class = class_create(THIS_MODULE, "ptp");
322 if (IS_ERR(ptp_class)) {
323 pr_err("ptp: failed to allocate class\n");
324 return PTR_ERR(ptp_class);
325 }
326
327 err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp");
328 if (err < 0) {
329 pr_err("ptp: failed to allocate device region\n");
330 goto no_region;
331 }
332
333 ptp_class->dev_groups = ptp_groups;
334 pr_info("PTP clock support registered\n");
335 return 0;
336
337no_region:
338 class_destroy(ptp_class);
339 return err;
340}
341
342subsys_initcall(ptp_init);
343module_exit(ptp_exit);
344
345MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
346MODULE_DESCRIPTION("PTP clocks support");
347MODULE_LICENSE("GPL");
348
