xref: /openbmc/linux/drivers/ptp/ptp_chardev.c (revision afb46f79)
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 		pr_err("sorry, cannot reassign the calibration pin\n");
90 		return -EINVAL;
91 	default:
92 		return -EINVAL;
93 	}
94 
95 	if (pin2->func == PTP_PF_PHYSYNC) {
96 		pr_err("sorry, cannot reprogram the calibration pin\n");
97 		return -EINVAL;
98 	}
99 
100 	if (info->verify(info, pin, func, chan)) {
101 		pr_err("driver cannot use function %u on pin %u\n", func, chan);
102 		return -EOPNOTSUPP;
103 	}
104 
105 	/* Disable whatever function was previously assigned. */
106 	if (pin1) {
107 		ptp_disable_pinfunc(info, func, chan);
108 		pin1->func = PTP_PF_NONE;
109 		pin1->chan = 0;
110 	}
111 	ptp_disable_pinfunc(info, pin2->func, pin2->chan);
112 	pin2->func = func;
113 	pin2->chan = chan;
114 
115 	return 0;
116 }
117 
118 int ptp_open(struct posix_clock *pc, fmode_t fmode)
119 {
120 	return 0;
121 }
122 
123 long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
124 {
125 	struct ptp_clock_caps caps;
126 	struct ptp_clock_request req;
127 	struct ptp_sys_offset *sysoff = NULL;
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 timespec ts;
133 	int enable, err = 0;
134 	unsigned int i, pin_index;
135 
136 	switch (cmd) {
137 
138 	case PTP_CLOCK_GETCAPS:
139 		memset(&caps, 0, sizeof(caps));
140 		caps.max_adj = ptp->info->max_adj;
141 		caps.n_alarm = ptp->info->n_alarm;
142 		caps.n_ext_ts = ptp->info->n_ext_ts;
143 		caps.n_per_out = ptp->info->n_per_out;
144 		caps.pps = ptp->info->pps;
145 		caps.n_pins = ptp->info->n_pins;
146 		if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
147 			err = -EFAULT;
148 		break;
149 
150 	case PTP_EXTTS_REQUEST:
151 		if (copy_from_user(&req.extts, (void __user *)arg,
152 				   sizeof(req.extts))) {
153 			err = -EFAULT;
154 			break;
155 		}
156 		if (req.extts.index >= ops->n_ext_ts) {
157 			err = -EINVAL;
158 			break;
159 		}
160 		req.type = PTP_CLK_REQ_EXTTS;
161 		enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
162 		err = ops->enable(ops, &req, enable);
163 		break;
164 
165 	case PTP_PEROUT_REQUEST:
166 		if (copy_from_user(&req.perout, (void __user *)arg,
167 				   sizeof(req.perout))) {
168 			err = -EFAULT;
169 			break;
170 		}
171 		if (req.perout.index >= ops->n_per_out) {
172 			err = -EINVAL;
173 			break;
174 		}
175 		req.type = PTP_CLK_REQ_PEROUT;
176 		enable = req.perout.period.sec || req.perout.period.nsec;
177 		err = ops->enable(ops, &req, enable);
178 		break;
179 
180 	case PTP_ENABLE_PPS:
181 		if (!capable(CAP_SYS_TIME))
182 			return -EPERM;
183 		req.type = PTP_CLK_REQ_PPS;
184 		enable = arg ? 1 : 0;
185 		err = ops->enable(ops, &req, enable);
186 		break;
187 
188 	case PTP_SYS_OFFSET:
189 		sysoff = kmalloc(sizeof(*sysoff), GFP_KERNEL);
190 		if (!sysoff) {
191 			err = -ENOMEM;
192 			break;
193 		}
194 		if (copy_from_user(sysoff, (void __user *)arg,
195 				   sizeof(*sysoff))) {
196 			err = -EFAULT;
197 			break;
198 		}
199 		if (sysoff->n_samples > PTP_MAX_SAMPLES) {
200 			err = -EINVAL;
201 			break;
202 		}
203 		pct = &sysoff->ts[0];
204 		for (i = 0; i < sysoff->n_samples; i++) {
205 			getnstimeofday(&ts);
206 			pct->sec = ts.tv_sec;
207 			pct->nsec = ts.tv_nsec;
208 			pct++;
209 			ptp->info->gettime(ptp->info, &ts);
210 			pct->sec = ts.tv_sec;
211 			pct->nsec = ts.tv_nsec;
212 			pct++;
213 		}
214 		getnstimeofday(&ts);
215 		pct->sec = ts.tv_sec;
216 		pct->nsec = ts.tv_nsec;
217 		if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
218 			err = -EFAULT;
219 		break;
220 
221 	case PTP_PIN_GETFUNC:
222 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
223 			err = -EFAULT;
224 			break;
225 		}
226 		pin_index = pd.index;
227 		if (pin_index >= ops->n_pins) {
228 			err = -EINVAL;
229 			break;
230 		}
231 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
232 			return -ERESTARTSYS;
233 		pd = ops->pin_config[pin_index];
234 		mutex_unlock(&ptp->pincfg_mux);
235 		if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
236 			err = -EFAULT;
237 		break;
238 
239 	case PTP_PIN_SETFUNC:
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 		err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
252 		mutex_unlock(&ptp->pincfg_mux);
253 		break;
254 
255 	default:
256 		err = -ENOTTY;
257 		break;
258 	}
259 
260 	kfree(sysoff);
261 	return err;
262 }
263 
264 unsigned int ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
265 {
266 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
267 
268 	poll_wait(fp, &ptp->tsev_wq, wait);
269 
270 	return queue_cnt(&ptp->tsevq) ? POLLIN : 0;
271 }
272 
273 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
274 
275 ssize_t ptp_read(struct posix_clock *pc,
276 		 uint rdflags, char __user *buf, size_t cnt)
277 {
278 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
279 	struct timestamp_event_queue *queue = &ptp->tsevq;
280 	struct ptp_extts_event *event;
281 	unsigned long flags;
282 	size_t qcnt, i;
283 	int result;
284 
285 	if (cnt % sizeof(struct ptp_extts_event) != 0)
286 		return -EINVAL;
287 
288 	if (cnt > EXTTS_BUFSIZE)
289 		cnt = EXTTS_BUFSIZE;
290 
291 	cnt = cnt / sizeof(struct ptp_extts_event);
292 
293 	if (mutex_lock_interruptible(&ptp->tsevq_mux))
294 		return -ERESTARTSYS;
295 
296 	if (wait_event_interruptible(ptp->tsev_wq,
297 				     ptp->defunct || queue_cnt(queue))) {
298 		mutex_unlock(&ptp->tsevq_mux);
299 		return -ERESTARTSYS;
300 	}
301 
302 	if (ptp->defunct) {
303 		mutex_unlock(&ptp->tsevq_mux);
304 		return -ENODEV;
305 	}
306 
307 	event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
308 	if (!event) {
309 		mutex_unlock(&ptp->tsevq_mux);
310 		return -ENOMEM;
311 	}
312 
313 	spin_lock_irqsave(&queue->lock, flags);
314 
315 	qcnt = queue_cnt(queue);
316 
317 	if (cnt > qcnt)
318 		cnt = qcnt;
319 
320 	for (i = 0; i < cnt; i++) {
321 		event[i] = queue->buf[queue->head];
322 		queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
323 	}
324 
325 	spin_unlock_irqrestore(&queue->lock, flags);
326 
327 	cnt = cnt * sizeof(struct ptp_extts_event);
328 
329 	mutex_unlock(&ptp->tsevq_mux);
330 
331 	result = cnt;
332 	if (copy_to_user(buf, event, cnt))
333 		result = -EFAULT;
334 
335 	kfree(event);
336 	return result;
337 }
338