6b13f685e
 김민수
BSP 최초 추가
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
/*
* pps-ldisc.c -- PPS line discipline
*
*
* Copyright (C) 2008 Rodolfo Giometti <giometti@linux.it>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/serial_core.h>
#include <linux/tty.h>
#include <linux/pps_kernel.h>
#include <linux/bug.h>
#define PPS_TTY_MAGIC 0x0001
static void pps_tty_dcd_change(struct tty_struct *tty, unsigned int status)
{
struct pps_device *pps;
struct pps_event_time ts;
pps_get_ts(&ts);
pps = pps_lookup_dev(tty);
/*
* This should never fail, but the ldisc locking is very
* convoluted, so don't crash just in case.
*/
if (WARN_ON_ONCE(pps == NULL))
return;
/* Now do the PPS event report */
pps_event(pps, &ts, status ? PPS_CAPTUREASSERT :
PPS_CAPTURECLEAR, NULL);
dev_dbg(pps->dev, "PPS %s at %lu
",
status ? "assert" : "clear", jiffies);
}
static int (*alias_n_tty_open)(struct tty_struct *tty);
static int pps_tty_open(struct tty_struct *tty)
{
struct pps_source_info info;
struct tty_driver *drv = tty->driver;
int index = tty->index + drv->name_base;
struct pps_device *pps;
int ret;
info.owner = THIS_MODULE;
info.dev = NULL;
snprintf(info.name, PPS_MAX_NAME_LEN, "%s%d", drv->driver_name, index);
snprintf(info.path, PPS_MAX_NAME_LEN, "/dev/%s%d", drv->name, index);
info.mode = PPS_CAPTUREBOTH | \
PPS_OFFSETASSERT | PPS_OFFSETCLEAR | \
PPS_CANWAIT | PPS_TSFMT_TSPEC;
pps = pps_register_source(&info, PPS_CAPTUREBOTH | \
PPS_OFFSETASSERT | PPS_OFFSETCLEAR);
if (pps == NULL) {
pr_err("cannot register PPS source \"%s\"
", info.path);
return -ENOMEM;
}
pps->lookup_cookie = tty;
/* Now open the base class N_TTY ldisc */
ret = alias_n_tty_open(tty);
if (ret < 0) {
pr_err("cannot open tty ldisc \"%s\"
", info.path);
goto err_unregister;
}
dev_info(pps->dev, "source \"%s\" added
", info.path);
return 0;
err_unregister:
pps_unregister_source(pps);
return ret;
}
static void (*alias_n_tty_close)(struct tty_struct *tty);
static void pps_tty_close(struct tty_struct *tty)
{
struct pps_device *pps = pps_lookup_dev(tty);
alias_n_tty_close(tty);
if (WARN_ON(!pps))
return;
dev_info(pps->dev, "removed
");
pps_unregister_source(pps);
}
static struct tty_ldisc_ops pps_ldisc_ops;
/*
* Module stuff
*/
static int __init pps_tty_init(void)
{
int err;
/* Inherit the N_TTY's ops */
n_tty_inherit_ops(&pps_ldisc_ops);
/* Save N_TTY's open()/close() methods */
alias_n_tty_open = pps_ldisc_ops.open;
alias_n_tty_close = pps_ldisc_ops.close;
/* Init PPS_TTY data */
pps_ldisc_ops.owner = THIS_MODULE;
pps_ldisc_ops.magic = PPS_TTY_MAGIC;
pps_ldisc_ops.name = "pps_tty";
pps_ldisc_ops.dcd_change = pps_tty_dcd_change;
pps_ldisc_ops.open = pps_tty_open;
pps_ldisc_ops.close = pps_tty_close;
err = tty_register_ldisc(N_PPS, &pps_ldisc_ops);
if (err)
pr_err("can't register PPS line discipline
");
else
pr_info("PPS line discipline registered
");
return err;
}
static void __exit pps_tty_cleanup(void)
{
int err;
err = tty_unregister_ldisc(N_PPS);
if (err)
pr_err("can't unregister PPS line discipline
");
else
pr_info("PPS line discipline removed
");
}
module_init(pps_tty_init);
module_exit(pps_tty_cleanup);
MODULE_ALIAS_LDISC(N_PPS);
MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
MODULE_DESCRIPTION("PPS TTY device driver");
MODULE_LICENSE("GPL");
|