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1/*
2 * kernel API
3 *
4 *
5 * Copyright (C) 2005-2009 Rodolfo Giometti <giometti@linux.it>
6 *
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.
11 *
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.
16 *
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.
20 */
21
22#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23
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>
31#include <linux/fs.h>
32#include <linux/pps_kernel.h>
33#include <linux/slab.h>
34
35#include "kc.h"
36
37/*
38 * Local functions
39 */
40
41static void pps_add_offset(struct pps_ktime *ts, struct pps_ktime *offset)
42{
43 ts->nsec += offset->nsec;
44 while (ts->nsec >= NSEC_PER_SEC) {
45 ts->nsec -= NSEC_PER_SEC;
46 ts->sec++;
47 }
48 while (ts->nsec < 0) {
49 ts->nsec += NSEC_PER_SEC;
50 ts->sec--;
51 }
52 ts->sec += offset->sec;
53}
54
55/*
56 * Exported functions
57 */
58
59/* pps_register_source - add a PPS source in the system
60 * @info: the PPS info struct
61 * @default_params: the default PPS parameters of the new source
62 *
63 * This function is used to add a new PPS source in the system. The new
64 * source is described by info's fields and it will have, as default PPS
65 * parameters, the ones specified into default_params.
66 *
67 * The function returns, in case of success, the PPS device. Otherwise NULL.
68 */
69
70struct pps_device *pps_register_source(struct pps_source_info *info,
71 int default_params)
72{
73 struct pps_device *pps;
74 int err;
75
76 /* Sanity checks */
77 if ((info->mode & default_params) != default_params) {
78 pr_err("%s: unsupported default parameters\n",
79 info->name);
80 err = -EINVAL;
81 goto pps_register_source_exit;
82 }
83 if ((info->mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)) != 0 &&
84 info->echo == NULL) {
85 pr_err("%s: echo function is not defined\n",
86 info->name);
87 err = -EINVAL;
88 goto pps_register_source_exit;
89 }
90 if ((info->mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) {
91 pr_err("%s: unspecified time format\n",
92 info->name);
93 err = -EINVAL;
94 goto pps_register_source_exit;
95 }
96
97 /* Allocate memory for the new PPS source struct */
98 pps = kzalloc(sizeof(struct pps_device), GFP_KERNEL);
99 if (pps == NULL) {
100 err = -ENOMEM;
101 goto pps_register_source_exit;
102 }
103
104 /* These initializations must be done before calling idr_get_new()
105 * in order to avoid reces into pps_event().
106 */
107 pps->params.api_version = PPS_API_VERS;
108 pps->params.mode = default_params;
109 pps->info = *info;
110
111 init_waitqueue_head(&pps->queue);
112 spin_lock_init(&pps->lock);
113
114 /* Create the char device */
115 err = pps_register_cdev(pps);
116 if (err < 0) {
117 pr_err("%s: unable to create char device\n",
118 info->name);
119 goto kfree_pps;
120 }
121
122 dev_info(pps->dev, "new PPS source %s\n", info->name);
123
124 return pps;
125
126kfree_pps:
127 kfree(pps);
128
129pps_register_source_exit:
130 pr_err("%s: unable to register source\n", info->name);
131
132 return NULL;
133}
134EXPORT_SYMBOL(pps_register_source);
135
136/* pps_unregister_source - remove a PPS source from the system
137 * @pps: the PPS source
138 *
139 * This function is used to remove a previously registered PPS source from
140 * the system.
141 */
142
143void pps_unregister_source(struct pps_device *pps)
144{
145 pps_kc_remove(pps);
146 pps_unregister_cdev(pps);
147
148 /* don't have to kfree(pps) here because it will be done on
149 * device destruction */
150}
151EXPORT_SYMBOL(pps_unregister_source);
152
153/* pps_event - register a PPS event into the system
154 * @pps: the PPS device
155 * @ts: the event timestamp
156 * @event: the event type
157 * @data: userdef pointer
158 *
159 * This function is used by each PPS client in order to register a new
160 * PPS event into the system (it's usually called inside an IRQ handler).
161 *
162 * If an echo function is associated with the PPS device it will be called
163 * as:
164 * pps->info.echo(pps, event, data);
165 */
166void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event,
167 void *data)
168{
169 unsigned long flags;
170 int captured = 0;
171 struct pps_ktime ts_real = { .sec = 0, .nsec = 0, .flags = 0 };
172
173 /* check event type */
174 BUG_ON((event & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0);
175
176 dev_dbg(pps->dev, "PPS event at %ld.%09ld\n",
177 ts->ts_real.tv_sec, ts->ts_real.tv_nsec);
178
179 timespec_to_pps_ktime(&ts_real, ts->ts_real);
180
181 spin_lock_irqsave(&pps->lock, flags);
182
183 /* Must call the echo function? */
184 if ((pps->params.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)))
185 pps->info.echo(pps, event, data);
186
187 /* Check the event */
188 pps->current_mode = pps->params.mode;
189 if (event & pps->params.mode & PPS_CAPTUREASSERT) {
190 /* We have to add an offset? */
191 if (pps->params.mode & PPS_OFFSETASSERT)
192 pps_add_offset(&ts_real,
193 &pps->params.assert_off_tu);
194
195 /* Save the time stamp */
196 pps->assert_tu = ts_real;
197 pps->assert_sequence++;
198 dev_dbg(pps->dev, "capture assert seq #%u\n",
199 pps->assert_sequence);
200
201 captured = ~0;
202 }
203 if (event & pps->params.mode & PPS_CAPTURECLEAR) {
204 /* We have to add an offset? */
205 if (pps->params.mode & PPS_OFFSETCLEAR)
206 pps_add_offset(&ts_real,
207 &pps->params.clear_off_tu);
208
209 /* Save the time stamp */
210 pps->clear_tu = ts_real;
211 pps->clear_sequence++;
212 dev_dbg(pps->dev, "capture clear seq #%u\n",
213 pps->clear_sequence);
214
215 captured = ~0;
216 }
217
218 pps_kc_event(pps, ts, event);
219
220 /* Wake up if captured something */
221 if (captured) {
222 pps->last_ev++;
223 wake_up_interruptible_all(&pps->queue);
224
225 kill_fasync(&pps->async_queue, SIGIO, POLL_IN);
226 }
227
228 spin_unlock_irqrestore(&pps->lock, flags);
229}
230EXPORT_SYMBOL(pps_event);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * kernel API
4 *
5 * Copyright (C) 2005-2009 Rodolfo Giometti <giometti@linux.it>
6 */
7
8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/init.h>
13#include <linux/sched.h>
14#include <linux/time.h>
15#include <linux/timex.h>
16#include <linux/spinlock.h>
17#include <linux/fs.h>
18#include <linux/pps_kernel.h>
19#include <linux/slab.h>
20
21#include "kc.h"
22
23/*
24 * Local functions
25 */
26
27static void pps_add_offset(struct pps_ktime *ts, struct pps_ktime *offset)
28{
29 ts->nsec += offset->nsec;
30 while (ts->nsec >= NSEC_PER_SEC) {
31 ts->nsec -= NSEC_PER_SEC;
32 ts->sec++;
33 }
34 while (ts->nsec < 0) {
35 ts->nsec += NSEC_PER_SEC;
36 ts->sec--;
37 }
38 ts->sec += offset->sec;
39}
40
41static void pps_echo_client_default(struct pps_device *pps, int event,
42 void *data)
43{
44 dev_info(&pps->dev, "echo %s %s\n",
45 event & PPS_CAPTUREASSERT ? "assert" : "",
46 event & PPS_CAPTURECLEAR ? "clear" : "");
47}
48
49/*
50 * Exported functions
51 */
52
53/* pps_register_source - add a PPS source in the system
54 * @info: the PPS info struct
55 * @default_params: the default PPS parameters of the new source
56 *
57 * This function is used to add a new PPS source in the system. The new
58 * source is described by info's fields and it will have, as default PPS
59 * parameters, the ones specified into default_params.
60 *
61 * The function returns, in case of success, the PPS device. Otherwise
62 * ERR_PTR(errno).
63 */
64
65struct pps_device *pps_register_source(struct pps_source_info *info,
66 int default_params)
67{
68 struct pps_device *pps;
69 int err;
70
71 /* Sanity checks */
72 if ((info->mode & default_params) != default_params) {
73 pr_err("%s: unsupported default parameters\n",
74 info->name);
75 err = -EINVAL;
76 goto pps_register_source_exit;
77 }
78 if ((info->mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) {
79 pr_err("%s: unspecified time format\n",
80 info->name);
81 err = -EINVAL;
82 goto pps_register_source_exit;
83 }
84
85 /* Allocate memory for the new PPS source struct */
86 pps = kzalloc(sizeof(struct pps_device), GFP_KERNEL);
87 if (pps == NULL) {
88 err = -ENOMEM;
89 goto pps_register_source_exit;
90 }
91
92 /* These initializations must be done before calling idr_alloc()
93 * in order to avoid reces into pps_event().
94 */
95 pps->params.api_version = PPS_API_VERS;
96 pps->params.mode = default_params;
97 pps->info = *info;
98
99 /* check for default echo function */
100 if ((pps->info.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)) &&
101 pps->info.echo == NULL)
102 pps->info.echo = pps_echo_client_default;
103
104 init_waitqueue_head(&pps->queue);
105 spin_lock_init(&pps->lock);
106
107 /* Create the char device */
108 err = pps_register_cdev(pps);
109 if (err < 0) {
110 pr_err("%s: unable to create char device\n",
111 info->name);
112 goto kfree_pps;
113 }
114
115 dev_dbg(&pps->dev, "new PPS source %s\n", info->name);
116
117 return pps;
118
119kfree_pps:
120 kfree(pps);
121
122pps_register_source_exit:
123 pr_err("%s: unable to register source\n", info->name);
124
125 return ERR_PTR(err);
126}
127EXPORT_SYMBOL(pps_register_source);
128
129/* pps_unregister_source - remove a PPS source from the system
130 * @pps: the PPS source
131 *
132 * This function is used to remove a previously registered PPS source from
133 * the system.
134 */
135
136void pps_unregister_source(struct pps_device *pps)
137{
138 pps_kc_remove(pps);
139 pps_unregister_cdev(pps);
140
141 /* don't have to kfree(pps) here because it will be done on
142 * device destruction */
143}
144EXPORT_SYMBOL(pps_unregister_source);
145
146/* pps_event - register a PPS event into the system
147 * @pps: the PPS device
148 * @ts: the event timestamp
149 * @event: the event type
150 * @data: userdef pointer
151 *
152 * This function is used by each PPS client in order to register a new
153 * PPS event into the system (it's usually called inside an IRQ handler).
154 *
155 * If an echo function is associated with the PPS device it will be called
156 * as:
157 * pps->info.echo(pps, event, data);
158 */
159void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event,
160 void *data)
161{
162 unsigned long flags;
163 int captured = 0;
164 struct pps_ktime ts_real = { .sec = 0, .nsec = 0, .flags = 0 };
165
166 /* check event type */
167 BUG_ON((event & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0);
168
169 dev_dbg(&pps->dev, "PPS event at %lld.%09ld\n",
170 (s64)ts->ts_real.tv_sec, ts->ts_real.tv_nsec);
171
172 timespec_to_pps_ktime(&ts_real, ts->ts_real);
173
174 spin_lock_irqsave(&pps->lock, flags);
175
176 /* Must call the echo function? */
177 if ((pps->params.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)))
178 pps->info.echo(pps, event, data);
179
180 /* Check the event */
181 pps->current_mode = pps->params.mode;
182 if (event & pps->params.mode & PPS_CAPTUREASSERT) {
183 /* We have to add an offset? */
184 if (pps->params.mode & PPS_OFFSETASSERT)
185 pps_add_offset(&ts_real,
186 &pps->params.assert_off_tu);
187
188 /* Save the time stamp */
189 pps->assert_tu = ts_real;
190 pps->assert_sequence++;
191 dev_dbg(&pps->dev, "capture assert seq #%u\n",
192 pps->assert_sequence);
193
194 captured = ~0;
195 }
196 if (event & pps->params.mode & PPS_CAPTURECLEAR) {
197 /* We have to add an offset? */
198 if (pps->params.mode & PPS_OFFSETCLEAR)
199 pps_add_offset(&ts_real,
200 &pps->params.clear_off_tu);
201
202 /* Save the time stamp */
203 pps->clear_tu = ts_real;
204 pps->clear_sequence++;
205 dev_dbg(&pps->dev, "capture clear seq #%u\n",
206 pps->clear_sequence);
207
208 captured = ~0;
209 }
210
211 pps_kc_event(pps, ts, event);
212
213 /* Wake up if captured something */
214 if (captured) {
215 pps->last_ev++;
216 wake_up_interruptible_all(&pps->queue);
217
218 kill_fasync(&pps->async_queue, SIGIO, POLL_IN);
219 }
220
221 spin_unlock_irqrestore(&pps->lock, flags);
222}
223EXPORT_SYMBOL(pps_event);