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[karo-tx-linux.git] / drivers / ptp / ptp_chardev.c
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 }