xref: /openbmc/linux/drivers/ptp/ptp_chardev.c (revision 0984d159)
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 		ts = ktime_to_timespec64(xtstamp.device);
197 		precise_offset.device.sec = ts.tv_sec;
198 		precise_offset.device.nsec = ts.tv_nsec;
199 		ts = ktime_to_timespec64(xtstamp.sys_realtime);
200 		precise_offset.sys_realtime.sec = ts.tv_sec;
201 		precise_offset.sys_realtime.nsec = ts.tv_nsec;
202 		ts = ktime_to_timespec64(xtstamp.sys_monoraw);
203 		precise_offset.sys_monoraw.sec = ts.tv_sec;
204 		precise_offset.sys_monoraw.nsec = ts.tv_nsec;
205 		if (copy_to_user((void __user *)arg, &precise_offset,
206 				 sizeof(precise_offset)))
207 			err = -EFAULT;
208 		break;
209 
210 	case PTP_SYS_OFFSET:
211 		sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
212 		if (IS_ERR(sysoff)) {
213 			err = PTR_ERR(sysoff);
214 			sysoff = NULL;
215 			break;
216 		}
217 		if (sysoff->n_samples > PTP_MAX_SAMPLES) {
218 			err = -EINVAL;
219 			break;
220 		}
221 		pct = &sysoff->ts[0];
222 		for (i = 0; i < sysoff->n_samples; i++) {
223 			getnstimeofday64(&ts);
224 			pct->sec = ts.tv_sec;
225 			pct->nsec = ts.tv_nsec;
226 			pct++;
227 			ptp->info->gettime64(ptp->info, &ts);
228 			pct->sec = ts.tv_sec;
229 			pct->nsec = ts.tv_nsec;
230 			pct++;
231 		}
232 		getnstimeofday64(&ts);
233 		pct->sec = ts.tv_sec;
234 		pct->nsec = ts.tv_nsec;
235 		if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
236 			err = -EFAULT;
237 		break;
238 
239 	case PTP_PIN_GETFUNC:
240 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
241 			err = -EFAULT;
242 			break;
243 		}
244 		pin_index = pd.index;
245 		if (pin_index >= ops->n_pins) {
246 			err = -EINVAL;
247 			break;
248 		}
249 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
250 			return -ERESTARTSYS;
251 		pd = ops->pin_config[pin_index];
252 		mutex_unlock(&ptp->pincfg_mux);
253 		if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
254 			err = -EFAULT;
255 		break;
256 
257 	case PTP_PIN_SETFUNC:
258 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
259 			err = -EFAULT;
260 			break;
261 		}
262 		pin_index = pd.index;
263 		if (pin_index >= ops->n_pins) {
264 			err = -EINVAL;
265 			break;
266 		}
267 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
268 			return -ERESTARTSYS;
269 		err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
270 		mutex_unlock(&ptp->pincfg_mux);
271 		break;
272 
273 	default:
274 		err = -ENOTTY;
275 		break;
276 	}
277 
278 	kfree(sysoff);
279 	return err;
280 }
281 
282 unsigned int ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
283 {
284 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
285 
286 	poll_wait(fp, &ptp->tsev_wq, wait);
287 
288 	return queue_cnt(&ptp->tsevq) ? POLLIN : 0;
289 }
290 
291 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
292 
293 ssize_t ptp_read(struct posix_clock *pc,
294 		 uint rdflags, char __user *buf, size_t cnt)
295 {
296 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
297 	struct timestamp_event_queue *queue = &ptp->tsevq;
298 	struct ptp_extts_event *event;
299 	unsigned long flags;
300 	size_t qcnt, i;
301 	int result;
302 
303 	if (cnt % sizeof(struct ptp_extts_event) != 0)
304 		return -EINVAL;
305 
306 	if (cnt > EXTTS_BUFSIZE)
307 		cnt = EXTTS_BUFSIZE;
308 
309 	cnt = cnt / sizeof(struct ptp_extts_event);
310 
311 	if (mutex_lock_interruptible(&ptp->tsevq_mux))
312 		return -ERESTARTSYS;
313 
314 	if (wait_event_interruptible(ptp->tsev_wq,
315 				     ptp->defunct || queue_cnt(queue))) {
316 		mutex_unlock(&ptp->tsevq_mux);
317 		return -ERESTARTSYS;
318 	}
319 
320 	if (ptp->defunct) {
321 		mutex_unlock(&ptp->tsevq_mux);
322 		return -ENODEV;
323 	}
324 
325 	event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
326 	if (!event) {
327 		mutex_unlock(&ptp->tsevq_mux);
328 		return -ENOMEM;
329 	}
330 
331 	spin_lock_irqsave(&queue->lock, flags);
332 
333 	qcnt = queue_cnt(queue);
334 
335 	if (cnt > qcnt)
336 		cnt = qcnt;
337 
338 	for (i = 0; i < cnt; i++) {
339 		event[i] = queue->buf[queue->head];
340 		queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
341 	}
342 
343 	spin_unlock_irqrestore(&queue->lock, flags);
344 
345 	cnt = cnt * sizeof(struct ptp_extts_event);
346 
347 	mutex_unlock(&ptp->tsevq_mux);
348 
349 	result = cnt;
350 	if (copy_to_user(buf, event, cnt))
351 		result = -EFAULT;
352 
353 	kfree(event);
354 	return result;
355 }
356