1 /*
2 * PTP 1588 clock support - character device implementation.
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/module.h>
21 #include <linux/posix-clock.h>
22 #include <linux/poll.h>
23 #include <linux/sched.h>
24 #include <linux/slab.h>
25 #include <linux/timekeeping.h>
26
27 #include <linux/nospec.h>
28
29 #include "ptp_private.h"
30
ptp_disable_pinfunc(struct ptp_clock_info * ops,enum ptp_pin_function func,unsigned int chan)31 static int ptp_disable_pinfunc(struct ptp_clock_info *ops,
32 enum ptp_pin_function func, unsigned int chan)
33 {
34 struct ptp_clock_request rq;
35 int err = 0;
36
37 memset(&rq, 0, sizeof(rq));
38
39 switch (func) {
40 case PTP_PF_NONE:
41 break;
42 case PTP_PF_EXTTS:
43 rq.type = PTP_CLK_REQ_EXTTS;
44 rq.extts.index = chan;
45 err = ops->enable(ops, &rq, 0);
46 break;
47 case PTP_PF_PEROUT:
48 rq.type = PTP_CLK_REQ_PEROUT;
49 rq.perout.index = chan;
50 err = ops->enable(ops, &rq, 0);
51 break;
52 case PTP_PF_PHYSYNC:
53 break;
54 default:
55 return -EINVAL;
56 }
57
58 return err;
59 }
60
ptp_set_pinfunc(struct ptp_clock * ptp,unsigned int pin,enum ptp_pin_function func,unsigned int chan)61 int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
62 enum ptp_pin_function func, unsigned int chan)
63 {
64 struct ptp_clock_info *info = ptp->info;
65 struct ptp_pin_desc *pin1 = NULL, *pin2 = &info->pin_config[pin];
66 unsigned int i;
67
68 /* Check to see if any other pin previously had this function. */
69 for (i = 0; i < info->n_pins; i++) {
70 if (info->pin_config[i].func == func &&
71 info->pin_config[i].chan == chan) {
72 pin1 = &info->pin_config[i];
73 break;
74 }
75 }
76 if (pin1 && i == pin)
77 return 0;
78
79 /* Check the desired function and channel. */
80 switch (func) {
81 case PTP_PF_NONE:
82 break;
83 case PTP_PF_EXTTS:
84 if (chan >= info->n_ext_ts)
85 return -EINVAL;
86 break;
87 case PTP_PF_PEROUT:
88 if (chan >= info->n_per_out)
89 return -EINVAL;
90 break;
91 case PTP_PF_PHYSYNC:
92 if (chan != 0)
93 return -EINVAL;
94 break;
95 default:
96 return -EINVAL;
97 }
98
99 if (info->verify(info, pin, func, chan)) {
100 pr_err("driver cannot use function %u on pin %u\n", func, chan);
101 return -EOPNOTSUPP;
102 }
103
104 /* Disable whatever function was previously assigned. */
105 if (pin1) {
106 ptp_disable_pinfunc(info, func, chan);
107 pin1->func = PTP_PF_NONE;
108 pin1->chan = 0;
109 }
110 ptp_disable_pinfunc(info, pin2->func, pin2->chan);
111 pin2->func = func;
112 pin2->chan = chan;
113
114 return 0;
115 }
116
ptp_open(struct posix_clock * pc,fmode_t fmode)117 int ptp_open(struct posix_clock *pc, fmode_t fmode)
118 {
119 return 0;
120 }
121
ptp_ioctl(struct posix_clock * pc,unsigned int cmd,unsigned long arg)122 long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
123 {
124 struct ptp_clock_caps caps;
125 struct ptp_clock_request req;
126 struct ptp_sys_offset *sysoff = NULL;
127 struct ptp_sys_offset_precise precise_offset;
128 struct ptp_pin_desc pd;
129 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
130 struct ptp_clock_info *ops = ptp->info;
131 struct ptp_clock_time *pct;
132 struct timespec64 ts;
133 struct system_device_crosststamp xtstamp;
134 int enable, err = 0;
135 unsigned int i, pin_index;
136
137 switch (cmd) {
138
139 case PTP_CLOCK_GETCAPS:
140 memset(&caps, 0, sizeof(caps));
141 caps.max_adj = ptp->info->max_adj;
142 caps.n_alarm = ptp->info->n_alarm;
143 caps.n_ext_ts = ptp->info->n_ext_ts;
144 caps.n_per_out = ptp->info->n_per_out;
145 caps.pps = ptp->info->pps;
146 caps.n_pins = ptp->info->n_pins;
147 caps.cross_timestamping = ptp->info->getcrosststamp != NULL;
148 if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
149 err = -EFAULT;
150 break;
151
152 case PTP_EXTTS_REQUEST:
153 if (copy_from_user(&req.extts, (void __user *)arg,
154 sizeof(req.extts))) {
155 err = -EFAULT;
156 break;
157 }
158 if (req.extts.index >= ops->n_ext_ts) {
159 err = -EINVAL;
160 break;
161 }
162 req.type = PTP_CLK_REQ_EXTTS;
163 enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
164 err = ops->enable(ops, &req, enable);
165 break;
166
167 case PTP_PEROUT_REQUEST:
168 if (copy_from_user(&req.perout, (void __user *)arg,
169 sizeof(req.perout))) {
170 err = -EFAULT;
171 break;
172 }
173 if (req.perout.index >= ops->n_per_out) {
174 err = -EINVAL;
175 break;
176 }
177 req.type = PTP_CLK_REQ_PEROUT;
178 enable = req.perout.period.sec || req.perout.period.nsec;
179 err = ops->enable(ops, &req, enable);
180 break;
181
182 case PTP_ENABLE_PPS:
183 if (!capable(CAP_SYS_TIME))
184 return -EPERM;
185 req.type = PTP_CLK_REQ_PPS;
186 enable = arg ? 1 : 0;
187 err = ops->enable(ops, &req, enable);
188 break;
189
190 case PTP_SYS_OFFSET_PRECISE:
191 if (!ptp->info->getcrosststamp) {
192 err = -EOPNOTSUPP;
193 break;
194 }
195 err = ptp->info->getcrosststamp(ptp->info, &xtstamp);
196 if (err)
197 break;
198
199 memset(&precise_offset, 0, sizeof(precise_offset));
200 ts = ktime_to_timespec64(xtstamp.device);
201 precise_offset.device.sec = ts.tv_sec;
202 precise_offset.device.nsec = ts.tv_nsec;
203 ts = ktime_to_timespec64(xtstamp.sys_realtime);
204 precise_offset.sys_realtime.sec = ts.tv_sec;
205 precise_offset.sys_realtime.nsec = ts.tv_nsec;
206 ts = ktime_to_timespec64(xtstamp.sys_monoraw);
207 precise_offset.sys_monoraw.sec = ts.tv_sec;
208 precise_offset.sys_monoraw.nsec = ts.tv_nsec;
209 if (copy_to_user((void __user *)arg, &precise_offset,
210 sizeof(precise_offset)))
211 err = -EFAULT;
212 break;
213
214 case PTP_SYS_OFFSET:
215 sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
216 if (IS_ERR(sysoff)) {
217 err = PTR_ERR(sysoff);
218 sysoff = NULL;
219 break;
220 }
221 if (sysoff->n_samples > PTP_MAX_SAMPLES) {
222 err = -EINVAL;
223 break;
224 }
225 pct = &sysoff->ts[0];
226 for (i = 0; i < sysoff->n_samples; i++) {
227 ktime_get_real_ts64(&ts);
228 pct->sec = ts.tv_sec;
229 pct->nsec = ts.tv_nsec;
230 pct++;
231 err = ptp->info->gettime64(ptp->info, &ts);
232 if (err)
233 goto out;
234 pct->sec = ts.tv_sec;
235 pct->nsec = ts.tv_nsec;
236 pct++;
237 }
238 ktime_get_real_ts64(&ts);
239 pct->sec = ts.tv_sec;
240 pct->nsec = ts.tv_nsec;
241 if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
242 err = -EFAULT;
243 break;
244
245 case PTP_PIN_GETFUNC:
246 if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
247 err = -EFAULT;
248 break;
249 }
250 pin_index = pd.index;
251 if (pin_index >= ops->n_pins) {
252 err = -EINVAL;
253 break;
254 }
255 pin_index = array_index_nospec(pin_index, ops->n_pins);
256 if (mutex_lock_interruptible(&ptp->pincfg_mux))
257 return -ERESTARTSYS;
258 pd = ops->pin_config[pin_index];
259 mutex_unlock(&ptp->pincfg_mux);
260 if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
261 err = -EFAULT;
262 break;
263
264 case PTP_PIN_SETFUNC:
265 if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
266 err = -EFAULT;
267 break;
268 }
269 pin_index = pd.index;
270 if (pin_index >= ops->n_pins) {
271 err = -EINVAL;
272 break;
273 }
274 pin_index = array_index_nospec(pin_index, ops->n_pins);
275 if (mutex_lock_interruptible(&ptp->pincfg_mux))
276 return -ERESTARTSYS;
277 err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
278 mutex_unlock(&ptp->pincfg_mux);
279 break;
280
281 default:
282 err = -ENOTTY;
283 break;
284 }
285
286 out:
287 kfree(sysoff);
288 return err;
289 }
290
ptp_poll(struct posix_clock * pc,struct file * fp,poll_table * wait)291 __poll_t ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
292 {
293 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
294
295 poll_wait(fp, &ptp->tsev_wq, wait);
296
297 return queue_cnt(&ptp->tsevq) ? EPOLLIN : 0;
298 }
299
300 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
301
ptp_read(struct posix_clock * pc,uint rdflags,char __user * buf,size_t cnt)302 ssize_t ptp_read(struct posix_clock *pc,
303 uint rdflags, char __user *buf, size_t cnt)
304 {
305 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
306 struct timestamp_event_queue *queue = &ptp->tsevq;
307 struct ptp_extts_event *event;
308 unsigned long flags;
309 size_t qcnt, i;
310 int result;
311
312 if (cnt % sizeof(struct ptp_extts_event) != 0)
313 return -EINVAL;
314
315 if (cnt > EXTTS_BUFSIZE)
316 cnt = EXTTS_BUFSIZE;
317
318 cnt = cnt / sizeof(struct ptp_extts_event);
319
320 if (mutex_lock_interruptible(&ptp->tsevq_mux))
321 return -ERESTARTSYS;
322
323 if (wait_event_interruptible(ptp->tsev_wq,
324 ptp->defunct || queue_cnt(queue))) {
325 mutex_unlock(&ptp->tsevq_mux);
326 return -ERESTARTSYS;
327 }
328
329 if (ptp->defunct) {
330 mutex_unlock(&ptp->tsevq_mux);
331 return -ENODEV;
332 }
333
334 event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
335 if (!event) {
336 mutex_unlock(&ptp->tsevq_mux);
337 return -ENOMEM;
338 }
339
340 spin_lock_irqsave(&queue->lock, flags);
341
342 qcnt = queue_cnt(queue);
343
344 if (cnt > qcnt)
345 cnt = qcnt;
346
347 for (i = 0; i < cnt; i++) {
348 event[i] = queue->buf[queue->head];
349 queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
350 }
351
352 spin_unlock_irqrestore(&queue->lock, flags);
353
354 cnt = cnt * sizeof(struct ptp_extts_event);
355
356 mutex_unlock(&ptp->tsevq_mux);
357
358 result = cnt;
359 if (copy_to_user(buf, event, cnt))
360 result = -EFAULT;
361
362 kfree(event);
363 return result;
364 }
365