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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 struct timespec64 ts = timespec_to_timespec64(*tp);
111
112 return ptp->info->settime64 ?
113 ptp->info->settime64(ptp->info, &ts) :
114 ptp->info->settime(ptp->info, tp);
115}
116
117static int ptp_clock_gettime(struct posix_clock *pc, struct timespec *tp)
118{
119 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
120 struct timespec64 ts;
121 int err;
122
123 if (ptp->info->gettime64) {
124 err = ptp->info->gettime64(ptp->info, &ts);
125 if (!err)
126 *tp = timespec64_to_timespec(ts);
127 } else {
128 err = ptp->info->gettime(ptp->info, tp);
129 }
130
131 return err;
132}
133
134static int ptp_clock_adjtime(struct posix_clock *pc, struct timex *tx)
135{
136 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
137 struct ptp_clock_info *ops;
138 int err = -EOPNOTSUPP;
139
140 ops = ptp->info;
141
142 if (tx->modes & ADJ_SETOFFSET) {
143 struct timespec ts;
144 ktime_t kt;
145 s64 delta;
146
147 ts.tv_sec = tx->time.tv_sec;
148 ts.tv_nsec = tx->time.tv_usec;
149
150 if (!(tx->modes & ADJ_NANO))
151 ts.tv_nsec *= 1000;
152
153 if ((unsigned long) ts.tv_nsec >= NSEC_PER_SEC)
154 return -EINVAL;
155
156 kt = timespec_to_ktime(ts);
157 delta = ktime_to_ns(kt);
158 err = ops->adjtime(ops, delta);
159 } else if (tx->modes & ADJ_FREQUENCY) {
160 s32 ppb = scaled_ppm_to_ppb(tx->freq);
161 if (ppb > ops->max_adj || ppb < -ops->max_adj)
162 return -ERANGE;
163 if (ops->adjfine)
164 err = ops->adjfine(ops, tx->freq);
165 else
166 err = ops->adjfreq(ops, ppb);
167 ptp->dialed_frequency = tx->freq;
168 } else if (tx->modes == 0) {
169 tx->freq = ptp->dialed_frequency;
170 err = 0;
171 }
172
173 return err;
174}
175
176static struct posix_clock_operations ptp_clock_ops = {
177 .owner = THIS_MODULE,
178 .clock_adjtime = ptp_clock_adjtime,
179 .clock_gettime = ptp_clock_gettime,
180 .clock_getres = ptp_clock_getres,
181 .clock_settime = ptp_clock_settime,
182 .ioctl = ptp_ioctl,
183 .open = ptp_open,
184 .poll = ptp_poll,
185 .read = ptp_read,
186};
187
188static void delete_ptp_clock(struct posix_clock *pc)
189{
190 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
191
192 mutex_destroy(&ptp->tsevq_mux);
193 mutex_destroy(&ptp->pincfg_mux);
194 ida_simple_remove(&ptp_clocks_map, ptp->index);
195 kfree(ptp);
196}
197
198
199
200struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
201 struct device *parent)
202{
203 struct ptp_clock *ptp;
204 int err = 0, index, major = MAJOR(ptp_devt);
205
206 if (info->n_alarm > PTP_MAX_ALARMS)
207 return ERR_PTR(-EINVAL);
208
209
210 err = -ENOMEM;
211 ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL);
212 if (ptp == NULL)
213 goto no_memory;
214
215 index = ida_simple_get(&ptp_clocks_map, 0, MINORMASK + 1, GFP_KERNEL);
216 if (index < 0) {
217 err = index;
218 goto no_slot;
219 }
220
221 ptp->clock.ops = ptp_clock_ops;
222 ptp->clock.release = delete_ptp_clock;
223 ptp->info = info;
224 ptp->devid = MKDEV(major, index);
225 ptp->index = index;
226 spin_lock_init(&ptp->tsevq.lock);
227 mutex_init(&ptp->tsevq_mux);
228 mutex_init(&ptp->pincfg_mux);
229 init_waitqueue_head(&ptp->tsev_wq);
230
231
232 ptp->dev = device_create(ptp_class, parent, ptp->devid, ptp,
233 "ptp%d", ptp->index);
234 if (IS_ERR(ptp->dev))
235 goto no_device;
236
237 dev_set_drvdata(ptp->dev, ptp);
238
239 err = ptp_populate_sysfs(ptp);
240 if (err)
241 goto no_sysfs;
242
243
244 if (info->pps) {
245 struct pps_source_info pps;
246 memset(&pps, 0, sizeof(pps));
247 snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index);
248 pps.mode = PTP_PPS_MODE;
249 pps.owner = info->owner;
250 ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS);
251 if (!ptp->pps_source) {
252 pr_err("failed to register pps source\n");
253 goto no_pps;
254 }
255 }
256
257
258 err = posix_clock_register(&ptp->clock, ptp->devid);
259 if (err) {
260 pr_err("failed to create posix clock\n");
261 goto no_clock;
262 }
263
264 return ptp;
265
266no_clock:
267 if (ptp->pps_source)
268 pps_unregister_source(ptp->pps_source);
269no_pps:
270 ptp_cleanup_sysfs(ptp);
271no_sysfs:
272 device_destroy(ptp_class, ptp->devid);
273no_device:
274 mutex_destroy(&ptp->tsevq_mux);
275 mutex_destroy(&ptp->pincfg_mux);
276no_slot:
277 kfree(ptp);
278no_memory:
279 return ERR_PTR(err);
280}
281EXPORT_SYMBOL(ptp_clock_register);
282
283int ptp_clock_unregister(struct ptp_clock *ptp)
284{
285 ptp->defunct = 1;
286 wake_up_interruptible(&ptp->tsev_wq);
287
288
289 if (ptp->pps_source)
290 pps_unregister_source(ptp->pps_source);
291 ptp_cleanup_sysfs(ptp);
292 device_destroy(ptp_class, ptp->devid);
293
294 posix_clock_unregister(&ptp->clock);
295 return 0;
296}
297EXPORT_SYMBOL(ptp_clock_unregister);
298
299void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
300{
301 struct pps_event_time evt;
302
303 switch (event->type) {
304
305 case PTP_CLOCK_ALARM:
306 break;
307
308 case PTP_CLOCK_EXTTS:
309 enqueue_external_timestamp(&ptp->tsevq, event);
310 wake_up_interruptible(&ptp->tsev_wq);
311 break;
312
313 case PTP_CLOCK_PPS:
314 pps_get_ts(&evt);
315 pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL);
316 break;
317
318 case PTP_CLOCK_PPSUSR:
319 pps_event(ptp->pps_source, &event->pps_times,
320 PTP_PPS_EVENT, NULL);
321 break;
322 }
323}
324EXPORT_SYMBOL(ptp_clock_event);
325
326int ptp_clock_index(struct ptp_clock *ptp)
327{
328 return ptp->index;
329}
330EXPORT_SYMBOL(ptp_clock_index);
331
332int ptp_find_pin(struct ptp_clock *ptp,
333 enum ptp_pin_function func, unsigned int chan)
334{
335 struct ptp_pin_desc *pin = NULL;
336 int i;
337
338 mutex_lock(&ptp->pincfg_mux);
339 for (i = 0; i < ptp->info->n_pins; i++) {
340 if (ptp->info->pin_config[i].func == func &&
341 ptp->info->pin_config[i].chan == chan) {
342 pin = &ptp->info->pin_config[i];
343 break;
344 }
345 }
346 mutex_unlock(&ptp->pincfg_mux);
347
348 return pin ? i : -1;
349}
350EXPORT_SYMBOL(ptp_find_pin);
351
352
353
354static void __exit ptp_exit(void)
355{
356 class_destroy(ptp_class);
357 unregister_chrdev_region(ptp_devt, MINORMASK + 1);
358 ida_destroy(&ptp_clocks_map);
359}
360
361static int __init ptp_init(void)
362{
363 int err;
364
365 ptp_class = class_create(THIS_MODULE, "ptp");
366 if (IS_ERR(ptp_class)) {
367 pr_err("ptp: failed to allocate class\n");
368 return PTR_ERR(ptp_class);
369 }
370
371 err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp");
372 if (err < 0) {
373 pr_err("ptp: failed to allocate device region\n");
374 goto no_region;
375 }
376
377 ptp_class->dev_groups = ptp_groups;
378 pr_info("PTP clock support registered\n");
379 return 0;
380
381no_region:
382 class_destroy(ptp_class);
383 return err;
384}
385
386subsys_initcall(ptp_init);
387module_exit(ptp_exit);
388
389MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
390MODULE_DESCRIPTION("PTP clocks support");
391MODULE_LICENSE("GPL");
392
