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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
28static 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
58int 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
113int ptp_open(struct posix_clock *pc, fmode_t fmode)
114{
115	return 0;
116}
117
118long 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 timespec 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			getnstimeofday(&ts);
201			pct->sec = ts.tv_sec;
202			pct->nsec = ts.tv_nsec;
203			pct++;
204			ptp->info->gettime(ptp->info, &ts);
205			pct->sec = ts.tv_sec;
206			pct->nsec = ts.tv_nsec;
207			pct++;
208		}
209		getnstimeofday(&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
259unsigned 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
270ssize_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