xref: /linux/drivers/ptp/ptp_chardev.c (revision c0e297dc61f8d4453e07afbea1fa8d0e67cd4a34)
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 
26 #include "ptp_private.h"
27 
28 static int ptp_disable_pinfunc(struct ptp_clock_info *ops,
29 			       enum ptp_pin_function func, unsigned int chan)
30 {
31 	struct ptp_clock_request rq;
32 	int err = 0;
33 
34 	memset(&rq, 0, sizeof(rq));
35 
36 	switch (func) {
37 	case PTP_PF_NONE:
38 		break;
39 	case PTP_PF_EXTTS:
40 		rq.type = PTP_CLK_REQ_EXTTS;
41 		rq.extts.index = chan;
42 		err = ops->enable(ops, &rq, 0);
43 		break;
44 	case PTP_PF_PEROUT:
45 		rq.type = PTP_CLK_REQ_PEROUT;
46 		rq.perout.index = chan;
47 		err = ops->enable(ops, &rq, 0);
48 		break;
49 	case PTP_PF_PHYSYNC:
50 		break;
51 	default:
52 		return -EINVAL;
53 	}
54 
55 	return err;
56 }
57 
58 int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
59 		    enum ptp_pin_function func, unsigned int chan)
60 {
61 	struct ptp_clock_info *info = ptp->info;
62 	struct ptp_pin_desc *pin1 = NULL, *pin2 = &info->pin_config[pin];
63 	unsigned int i;
64 
65 	/* Check to see if any other pin previously had this function. */
66 	for (i = 0; i < info->n_pins; i++) {
67 		if (info->pin_config[i].func == func &&
68 		    info->pin_config[i].chan == chan) {
69 			pin1 = &info->pin_config[i];
70 			break;
71 		}
72 	}
73 	if (pin1 && i == pin)
74 		return 0;
75 
76 	/* Check the desired function and channel. */
77 	switch (func) {
78 	case PTP_PF_NONE:
79 		break;
80 	case PTP_PF_EXTTS:
81 		if (chan >= info->n_ext_ts)
82 			return -EINVAL;
83 		break;
84 	case PTP_PF_PEROUT:
85 		if (chan >= info->n_per_out)
86 			return -EINVAL;
87 		break;
88 	case PTP_PF_PHYSYNC:
89 		if (chan != 0)
90 			return -EINVAL;
91 	default:
92 		return -EINVAL;
93 	}
94 
95 	if (info->verify(info, pin, func, chan)) {
96 		pr_err("driver cannot use function %u on pin %u\n", func, chan);
97 		return -EOPNOTSUPP;
98 	}
99 
100 	/* Disable whatever function was previously assigned. */
101 	if (pin1) {
102 		ptp_disable_pinfunc(info, func, chan);
103 		pin1->func = PTP_PF_NONE;
104 		pin1->chan = 0;
105 	}
106 	ptp_disable_pinfunc(info, pin2->func, pin2->chan);
107 	pin2->func = func;
108 	pin2->chan = chan;
109 
110 	return 0;
111 }
112 
113 int ptp_open(struct posix_clock *pc, fmode_t fmode)
114 {
115 	return 0;
116 }
117 
118 long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
119 {
120 	struct ptp_clock_caps caps;
121 	struct ptp_clock_request req;
122 	struct ptp_sys_offset *sysoff = NULL;
123 	struct ptp_pin_desc pd;
124 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
125 	struct ptp_clock_info *ops = ptp->info;
126 	struct ptp_clock_time *pct;
127 	struct timespec64 ts;
128 	int enable, err = 0;
129 	unsigned int i, pin_index;
130 
131 	switch (cmd) {
132 
133 	case PTP_CLOCK_GETCAPS:
134 		memset(&caps, 0, sizeof(caps));
135 		caps.max_adj = ptp->info->max_adj;
136 		caps.n_alarm = ptp->info->n_alarm;
137 		caps.n_ext_ts = ptp->info->n_ext_ts;
138 		caps.n_per_out = ptp->info->n_per_out;
139 		caps.pps = ptp->info->pps;
140 		caps.n_pins = ptp->info->n_pins;
141 		if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
142 			err = -EFAULT;
143 		break;
144 
145 	case PTP_EXTTS_REQUEST:
146 		if (copy_from_user(&req.extts, (void __user *)arg,
147 				   sizeof(req.extts))) {
148 			err = -EFAULT;
149 			break;
150 		}
151 		if (req.extts.index >= ops->n_ext_ts) {
152 			err = -EINVAL;
153 			break;
154 		}
155 		req.type = PTP_CLK_REQ_EXTTS;
156 		enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
157 		err = ops->enable(ops, &req, enable);
158 		break;
159 
160 	case PTP_PEROUT_REQUEST:
161 		if (copy_from_user(&req.perout, (void __user *)arg,
162 				   sizeof(req.perout))) {
163 			err = -EFAULT;
164 			break;
165 		}
166 		if (req.perout.index >= ops->n_per_out) {
167 			err = -EINVAL;
168 			break;
169 		}
170 		req.type = PTP_CLK_REQ_PEROUT;
171 		enable = req.perout.period.sec || req.perout.period.nsec;
172 		err = ops->enable(ops, &req, enable);
173 		break;
174 
175 	case PTP_ENABLE_PPS:
176 		if (!capable(CAP_SYS_TIME))
177 			return -EPERM;
178 		req.type = PTP_CLK_REQ_PPS;
179 		enable = arg ? 1 : 0;
180 		err = ops->enable(ops, &req, enable);
181 		break;
182 
183 	case PTP_SYS_OFFSET:
184 		sysoff = kmalloc(sizeof(*sysoff), GFP_KERNEL);
185 		if (!sysoff) {
186 			err = -ENOMEM;
187 			break;
188 		}
189 		if (copy_from_user(sysoff, (void __user *)arg,
190 				   sizeof(*sysoff))) {
191 			err = -EFAULT;
192 			break;
193 		}
194 		if (sysoff->n_samples > PTP_MAX_SAMPLES) {
195 			err = -EINVAL;
196 			break;
197 		}
198 		pct = &sysoff->ts[0];
199 		for (i = 0; i < sysoff->n_samples; i++) {
200 			getnstimeofday64(&ts);
201 			pct->sec = ts.tv_sec;
202 			pct->nsec = ts.tv_nsec;
203 			pct++;
204 			ptp->info->gettime64(ptp->info, &ts);
205 			pct->sec = ts.tv_sec;
206 			pct->nsec = ts.tv_nsec;
207 			pct++;
208 		}
209 		getnstimeofday64(&ts);
210 		pct->sec = ts.tv_sec;
211 		pct->nsec = ts.tv_nsec;
212 		if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
213 			err = -EFAULT;
214 		break;
215 
216 	case PTP_PIN_GETFUNC:
217 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
218 			err = -EFAULT;
219 			break;
220 		}
221 		pin_index = pd.index;
222 		if (pin_index >= ops->n_pins) {
223 			err = -EINVAL;
224 			break;
225 		}
226 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
227 			return -ERESTARTSYS;
228 		pd = ops->pin_config[pin_index];
229 		mutex_unlock(&ptp->pincfg_mux);
230 		if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
231 			err = -EFAULT;
232 		break;
233 
234 	case PTP_PIN_SETFUNC:
235 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
236 			err = -EFAULT;
237 			break;
238 		}
239 		pin_index = pd.index;
240 		if (pin_index >= ops->n_pins) {
241 			err = -EINVAL;
242 			break;
243 		}
244 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
245 			return -ERESTARTSYS;
246 		err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
247 		mutex_unlock(&ptp->pincfg_mux);
248 		break;
249 
250 	default:
251 		err = -ENOTTY;
252 		break;
253 	}
254 
255 	kfree(sysoff);
256 	return err;
257 }
258 
259 unsigned int ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
260 {
261 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
262 
263 	poll_wait(fp, &ptp->tsev_wq, wait);
264 
265 	return queue_cnt(&ptp->tsevq) ? POLLIN : 0;
266 }
267 
268 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
269 
270 ssize_t ptp_read(struct posix_clock *pc,
271 		 uint rdflags, char __user *buf, size_t cnt)
272 {
273 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
274 	struct timestamp_event_queue *queue = &ptp->tsevq;
275 	struct ptp_extts_event *event;
276 	unsigned long flags;
277 	size_t qcnt, i;
278 	int result;
279 
280 	if (cnt % sizeof(struct ptp_extts_event) != 0)
281 		return -EINVAL;
282 
283 	if (cnt > EXTTS_BUFSIZE)
284 		cnt = EXTTS_BUFSIZE;
285 
286 	cnt = cnt / sizeof(struct ptp_extts_event);
287 
288 	if (mutex_lock_interruptible(&ptp->tsevq_mux))
289 		return -ERESTARTSYS;
290 
291 	if (wait_event_interruptible(ptp->tsev_wq,
292 				     ptp->defunct || queue_cnt(queue))) {
293 		mutex_unlock(&ptp->tsevq_mux);
294 		return -ERESTARTSYS;
295 	}
296 
297 	if (ptp->defunct) {
298 		mutex_unlock(&ptp->tsevq_mux);
299 		return -ENODEV;
300 	}
301 
302 	event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
303 	if (!event) {
304 		mutex_unlock(&ptp->tsevq_mux);
305 		return -ENOMEM;
306 	}
307 
308 	spin_lock_irqsave(&queue->lock, flags);
309 
310 	qcnt = queue_cnt(queue);
311 
312 	if (cnt > qcnt)
313 		cnt = qcnt;
314 
315 	for (i = 0; i < cnt; i++) {
316 		event[i] = queue->buf[queue->head];
317 		queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
318 	}
319 
320 	spin_unlock_irqrestore(&queue->lock, flags);
321 
322 	cnt = cnt * sizeof(struct ptp_extts_event);
323 
324 	mutex_unlock(&ptp->tsevq_mux);
325 
326 	result = cnt;
327 	if (copy_to_user(buf, event, cnt))
328 		result = -EFAULT;
329 
330 	kfree(event);
331 	return result;
332 }
333