xref: /openbmc/linux/drivers/ptp/ptp_chardev.c (revision 1c2dd16a)
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 "ptp_private.h"
28 
29 static int ptp_disable_pinfunc(struct ptp_clock_info *ops,
30 			       enum ptp_pin_function func, unsigned int chan)
31 {
32 	struct ptp_clock_request rq;
33 	int err = 0;
34 
35 	memset(&rq, 0, sizeof(rq));
36 
37 	switch (func) {
38 	case PTP_PF_NONE:
39 		break;
40 	case PTP_PF_EXTTS:
41 		rq.type = PTP_CLK_REQ_EXTTS;
42 		rq.extts.index = chan;
43 		err = ops->enable(ops, &rq, 0);
44 		break;
45 	case PTP_PF_PEROUT:
46 		rq.type = PTP_CLK_REQ_PEROUT;
47 		rq.perout.index = chan;
48 		err = ops->enable(ops, &rq, 0);
49 		break;
50 	case PTP_PF_PHYSYNC:
51 		break;
52 	default:
53 		return -EINVAL;
54 	}
55 
56 	return err;
57 }
58 
59 int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
60 		    enum ptp_pin_function func, unsigned int chan)
61 {
62 	struct ptp_clock_info *info = ptp->info;
63 	struct ptp_pin_desc *pin1 = NULL, *pin2 = &info->pin_config[pin];
64 	unsigned int i;
65 
66 	/* Check to see if any other pin previously had this function. */
67 	for (i = 0; i < info->n_pins; i++) {
68 		if (info->pin_config[i].func == func &&
69 		    info->pin_config[i].chan == chan) {
70 			pin1 = &info->pin_config[i];
71 			break;
72 		}
73 	}
74 	if (pin1 && i == pin)
75 		return 0;
76 
77 	/* Check the desired function and channel. */
78 	switch (func) {
79 	case PTP_PF_NONE:
80 		break;
81 	case PTP_PF_EXTTS:
82 		if (chan >= info->n_ext_ts)
83 			return -EINVAL;
84 		break;
85 	case PTP_PF_PEROUT:
86 		if (chan >= info->n_per_out)
87 			return -EINVAL;
88 		break;
89 	case PTP_PF_PHYSYNC:
90 		if (chan != 0)
91 			return -EINVAL;
92 	default:
93 		return -EINVAL;
94 	}
95 
96 	if (info->verify(info, pin, func, chan)) {
97 		pr_err("driver cannot use function %u on pin %u\n", func, chan);
98 		return -EOPNOTSUPP;
99 	}
100 
101 	/* Disable whatever function was previously assigned. */
102 	if (pin1) {
103 		ptp_disable_pinfunc(info, func, chan);
104 		pin1->func = PTP_PF_NONE;
105 		pin1->chan = 0;
106 	}
107 	ptp_disable_pinfunc(info, pin2->func, pin2->chan);
108 	pin2->func = func;
109 	pin2->chan = chan;
110 
111 	return 0;
112 }
113 
114 int ptp_open(struct posix_clock *pc, fmode_t fmode)
115 {
116 	return 0;
117 }
118 
119 long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
120 {
121 	struct ptp_clock_caps caps;
122 	struct ptp_clock_request req;
123 	struct ptp_sys_offset *sysoff = NULL;
124 	struct ptp_sys_offset_precise precise_offset;
125 	struct ptp_pin_desc pd;
126 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
127 	struct ptp_clock_info *ops = ptp->info;
128 	struct ptp_clock_time *pct;
129 	struct timespec64 ts;
130 	struct system_device_crosststamp xtstamp;
131 	int enable, err = 0;
132 	unsigned int i, pin_index;
133 
134 	switch (cmd) {
135 
136 	case PTP_CLOCK_GETCAPS:
137 		memset(&caps, 0, sizeof(caps));
138 		caps.max_adj = ptp->info->max_adj;
139 		caps.n_alarm = ptp->info->n_alarm;
140 		caps.n_ext_ts = ptp->info->n_ext_ts;
141 		caps.n_per_out = ptp->info->n_per_out;
142 		caps.pps = ptp->info->pps;
143 		caps.n_pins = ptp->info->n_pins;
144 		caps.cross_timestamping = ptp->info->getcrosststamp != NULL;
145 		if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
146 			err = -EFAULT;
147 		break;
148 
149 	case PTP_EXTTS_REQUEST:
150 		if (copy_from_user(&req.extts, (void __user *)arg,
151 				   sizeof(req.extts))) {
152 			err = -EFAULT;
153 			break;
154 		}
155 		if (req.extts.index >= ops->n_ext_ts) {
156 			err = -EINVAL;
157 			break;
158 		}
159 		req.type = PTP_CLK_REQ_EXTTS;
160 		enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
161 		err = ops->enable(ops, &req, enable);
162 		break;
163 
164 	case PTP_PEROUT_REQUEST:
165 		if (copy_from_user(&req.perout, (void __user *)arg,
166 				   sizeof(req.perout))) {
167 			err = -EFAULT;
168 			break;
169 		}
170 		if (req.perout.index >= ops->n_per_out) {
171 			err = -EINVAL;
172 			break;
173 		}
174 		req.type = PTP_CLK_REQ_PEROUT;
175 		enable = req.perout.period.sec || req.perout.period.nsec;
176 		err = ops->enable(ops, &req, enable);
177 		break;
178 
179 	case PTP_ENABLE_PPS:
180 		if (!capable(CAP_SYS_TIME))
181 			return -EPERM;
182 		req.type = PTP_CLK_REQ_PPS;
183 		enable = arg ? 1 : 0;
184 		err = ops->enable(ops, &req, enable);
185 		break;
186 
187 	case PTP_SYS_OFFSET_PRECISE:
188 		if (!ptp->info->getcrosststamp) {
189 			err = -EOPNOTSUPP;
190 			break;
191 		}
192 		err = ptp->info->getcrosststamp(ptp->info, &xtstamp);
193 		if (err)
194 			break;
195 
196 		memset(&precise_offset, 0, sizeof(precise_offset));
197 		ts = ktime_to_timespec64(xtstamp.device);
198 		precise_offset.device.sec = ts.tv_sec;
199 		precise_offset.device.nsec = ts.tv_nsec;
200 		ts = ktime_to_timespec64(xtstamp.sys_realtime);
201 		precise_offset.sys_realtime.sec = ts.tv_sec;
202 		precise_offset.sys_realtime.nsec = ts.tv_nsec;
203 		ts = ktime_to_timespec64(xtstamp.sys_monoraw);
204 		precise_offset.sys_monoraw.sec = ts.tv_sec;
205 		precise_offset.sys_monoraw.nsec = ts.tv_nsec;
206 		if (copy_to_user((void __user *)arg, &precise_offset,
207 				 sizeof(precise_offset)))
208 			err = -EFAULT;
209 		break;
210 
211 	case PTP_SYS_OFFSET:
212 		sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
213 		if (IS_ERR(sysoff)) {
214 			err = PTR_ERR(sysoff);
215 			sysoff = NULL;
216 			break;
217 		}
218 		if (sysoff->n_samples > PTP_MAX_SAMPLES) {
219 			err = -EINVAL;
220 			break;
221 		}
222 		pct = &sysoff->ts[0];
223 		for (i = 0; i < sysoff->n_samples; i++) {
224 			getnstimeofday64(&ts);
225 			pct->sec = ts.tv_sec;
226 			pct->nsec = ts.tv_nsec;
227 			pct++;
228 			ptp->info->gettime64(ptp->info, &ts);
229 			pct->sec = ts.tv_sec;
230 			pct->nsec = ts.tv_nsec;
231 			pct++;
232 		}
233 		getnstimeofday64(&ts);
234 		pct->sec = ts.tv_sec;
235 		pct->nsec = ts.tv_nsec;
236 		if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
237 			err = -EFAULT;
238 		break;
239 
240 	case PTP_PIN_GETFUNC:
241 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
242 			err = -EFAULT;
243 			break;
244 		}
245 		pin_index = pd.index;
246 		if (pin_index >= ops->n_pins) {
247 			err = -EINVAL;
248 			break;
249 		}
250 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
251 			return -ERESTARTSYS;
252 		pd = ops->pin_config[pin_index];
253 		mutex_unlock(&ptp->pincfg_mux);
254 		if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
255 			err = -EFAULT;
256 		break;
257 
258 	case PTP_PIN_SETFUNC:
259 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
260 			err = -EFAULT;
261 			break;
262 		}
263 		pin_index = pd.index;
264 		if (pin_index >= ops->n_pins) {
265 			err = -EINVAL;
266 			break;
267 		}
268 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
269 			return -ERESTARTSYS;
270 		err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
271 		mutex_unlock(&ptp->pincfg_mux);
272 		break;
273 
274 	default:
275 		err = -ENOTTY;
276 		break;
277 	}
278 
279 	kfree(sysoff);
280 	return err;
281 }
282 
283 unsigned int ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
284 {
285 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
286 
287 	poll_wait(fp, &ptp->tsev_wq, wait);
288 
289 	return queue_cnt(&ptp->tsevq) ? POLLIN : 0;
290 }
291 
292 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
293 
294 ssize_t ptp_read(struct posix_clock *pc,
295 		 uint rdflags, char __user *buf, size_t cnt)
296 {
297 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
298 	struct timestamp_event_queue *queue = &ptp->tsevq;
299 	struct ptp_extts_event *event;
300 	unsigned long flags;
301 	size_t qcnt, i;
302 	int result;
303 
304 	if (cnt % sizeof(struct ptp_extts_event) != 0)
305 		return -EINVAL;
306 
307 	if (cnt > EXTTS_BUFSIZE)
308 		cnt = EXTTS_BUFSIZE;
309 
310 	cnt = cnt / sizeof(struct ptp_extts_event);
311 
312 	if (mutex_lock_interruptible(&ptp->tsevq_mux))
313 		return -ERESTARTSYS;
314 
315 	if (wait_event_interruptible(ptp->tsev_wq,
316 				     ptp->defunct || queue_cnt(queue))) {
317 		mutex_unlock(&ptp->tsevq_mux);
318 		return -ERESTARTSYS;
319 	}
320 
321 	if (ptp->defunct) {
322 		mutex_unlock(&ptp->tsevq_mux);
323 		return -ENODEV;
324 	}
325 
326 	event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
327 	if (!event) {
328 		mutex_unlock(&ptp->tsevq_mux);
329 		return -ENOMEM;
330 	}
331 
332 	spin_lock_irqsave(&queue->lock, flags);
333 
334 	qcnt = queue_cnt(queue);
335 
336 	if (cnt > qcnt)
337 		cnt = qcnt;
338 
339 	for (i = 0; i < cnt; i++) {
340 		event[i] = queue->buf[queue->head];
341 		queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
342 	}
343 
344 	spin_unlock_irqrestore(&queue->lock, flags);
345 
346 	cnt = cnt * sizeof(struct ptp_extts_event);
347 
348 	mutex_unlock(&ptp->tsevq_mux);
349 
350 	result = cnt;
351 	if (copy_to_user(buf, event, cnt))
352 		result = -EFAULT;
353 
354 	kfree(event);
355 	return result;
356 }
357