5 * Copyright (C) 2005-2009 Rodolfo Giometti <giometti@linux.it>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/init.h>
27 #include <linux/sched.h>
28 #include <linux/time.h>
29 #include <linux/timex.h>
30 #include <linux/spinlock.h>
32 #include <linux/pps_kernel.h>
33 #include <linux/slab.h>
41 static void pps_add_offset(struct pps_ktime
*ts
, struct pps_ktime
*offset
)
43 ts
->nsec
+= offset
->nsec
;
44 while (ts
->nsec
>= NSEC_PER_SEC
) {
45 ts
->nsec
-= NSEC_PER_SEC
;
48 while (ts
->nsec
< 0) {
49 ts
->nsec
+= NSEC_PER_SEC
;
52 ts
->sec
+= offset
->sec
;
55 static void pps_echo_client_default(struct pps_device
*pps
, int event
,
58 dev_info(pps
->dev
, "echo %s %s\n",
59 event
& PPS_CAPTUREASSERT
? "assert" : "",
60 event
& PPS_CAPTURECLEAR
? "clear" : "");
67 /* pps_register_source - add a PPS source in the system
68 * @info: the PPS info struct
69 * @default_params: the default PPS parameters of the new source
71 * This function is used to add a new PPS source in the system. The new
72 * source is described by info's fields and it will have, as default PPS
73 * parameters, the ones specified into default_params.
75 * The function returns, in case of success, the PPS device. Otherwise NULL.
78 struct pps_device
*pps_register_source(struct pps_source_info
*info
,
81 struct pps_device
*pps
;
85 if ((info
->mode
& default_params
) != default_params
) {
86 pr_err("%s: unsupported default parameters\n",
89 goto pps_register_source_exit
;
91 if ((info
->mode
& (PPS_TSFMT_TSPEC
| PPS_TSFMT_NTPFP
)) == 0) {
92 pr_err("%s: unspecified time format\n",
95 goto pps_register_source_exit
;
98 /* Allocate memory for the new PPS source struct */
99 pps
= kzalloc(sizeof(struct pps_device
), GFP_KERNEL
);
102 goto pps_register_source_exit
;
105 /* These initializations must be done before calling idr_alloc()
106 * in order to avoid reces into pps_event().
108 pps
->params
.api_version
= PPS_API_VERS
;
109 pps
->params
.mode
= default_params
;
112 /* check for default echo function */
113 if ((pps
->info
.mode
& (PPS_ECHOASSERT
| PPS_ECHOCLEAR
)) &&
114 pps
->info
.echo
== NULL
)
115 pps
->info
.echo
= pps_echo_client_default
;
117 init_waitqueue_head(&pps
->queue
);
118 spin_lock_init(&pps
->lock
);
120 /* Create the char device */
121 err
= pps_register_cdev(pps
);
123 pr_err("%s: unable to create char device\n",
128 dev_info(pps
->dev
, "new PPS source %s\n", info
->name
);
135 pps_register_source_exit
:
136 pr_err("%s: unable to register source\n", info
->name
);
140 EXPORT_SYMBOL(pps_register_source
);
142 /* pps_unregister_source - remove a PPS source from the system
143 * @pps: the PPS source
145 * This function is used to remove a previously registered PPS source from
149 void pps_unregister_source(struct pps_device
*pps
)
152 pps_unregister_cdev(pps
);
154 /* don't have to kfree(pps) here because it will be done on
155 * device destruction */
157 EXPORT_SYMBOL(pps_unregister_source
);
159 /* pps_event - register a PPS event into the system
160 * @pps: the PPS device
161 * @ts: the event timestamp
162 * @event: the event type
163 * @data: userdef pointer
165 * This function is used by each PPS client in order to register a new
166 * PPS event into the system (it's usually called inside an IRQ handler).
168 * If an echo function is associated with the PPS device it will be called
170 * pps->info.echo(pps, event, data);
172 void pps_event(struct pps_device
*pps
, struct pps_event_time
*ts
, int event
,
177 struct pps_ktime ts_real
= { .sec
= 0, .nsec
= 0, .flags
= 0 };
179 /* check event type */
180 BUG_ON((event
& (PPS_CAPTUREASSERT
| PPS_CAPTURECLEAR
)) == 0);
182 dev_dbg(pps
->dev
, "PPS event at %ld.%09ld\n",
183 ts
->ts_real
.tv_sec
, ts
->ts_real
.tv_nsec
);
185 timespec_to_pps_ktime(&ts_real
, ts
->ts_real
);
187 spin_lock_irqsave(&pps
->lock
, flags
);
189 /* Must call the echo function? */
190 if ((pps
->params
.mode
& (PPS_ECHOASSERT
| PPS_ECHOCLEAR
)))
191 pps
->info
.echo(pps
, event
, data
);
193 /* Check the event */
194 pps
->current_mode
= pps
->params
.mode
;
195 if (event
& pps
->params
.mode
& PPS_CAPTUREASSERT
) {
196 /* We have to add an offset? */
197 if (pps
->params
.mode
& PPS_OFFSETASSERT
)
198 pps_add_offset(&ts_real
,
199 &pps
->params
.assert_off_tu
);
201 /* Save the time stamp */
202 pps
->assert_tu
= ts_real
;
203 pps
->assert_sequence
++;
204 dev_dbg(pps
->dev
, "capture assert seq #%u\n",
205 pps
->assert_sequence
);
209 if (event
& pps
->params
.mode
& PPS_CAPTURECLEAR
) {
210 /* We have to add an offset? */
211 if (pps
->params
.mode
& PPS_OFFSETCLEAR
)
212 pps_add_offset(&ts_real
,
213 &pps
->params
.clear_off_tu
);
215 /* Save the time stamp */
216 pps
->clear_tu
= ts_real
;
217 pps
->clear_sequence
++;
218 dev_dbg(pps
->dev
, "capture clear seq #%u\n",
219 pps
->clear_sequence
);
224 pps_kc_event(pps
, ts
, event
);
226 /* Wake up if captured something */
229 wake_up_interruptible_all(&pps
->queue
);
231 kill_fasync(&pps
->async_queue
, SIGIO
, POLL_IN
);
234 spin_unlock_irqrestore(&pps
->lock
, flags
);
236 EXPORT_SYMBOL(pps_event
);
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