diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /sound/core/rtctimer.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'sound/core/rtctimer.c')
-rw-r--r-- | sound/core/rtctimer.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/sound/core/rtctimer.c b/sound/core/rtctimer.c new file mode 100644 index 000000000000..bd5d584d284d --- /dev/null +++ b/sound/core/rtctimer.c | |||
@@ -0,0 +1,188 @@ | |||
1 | /* | ||
2 | * RTC based high-frequency timer | ||
3 | * | ||
4 | * Copyright (C) 2000 Takashi Iwai | ||
5 | * based on rtctimer.c by Steve Ratcliffe | ||
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
20 | * | ||
21 | */ | ||
22 | |||
23 | #include <sound/driver.h> | ||
24 | #include <linux/init.h> | ||
25 | #include <linux/time.h> | ||
26 | #include <linux/threads.h> | ||
27 | #include <linux/interrupt.h> | ||
28 | #include <linux/moduleparam.h> | ||
29 | #include <sound/core.h> | ||
30 | #include <sound/timer.h> | ||
31 | #include <sound/info.h> | ||
32 | |||
33 | #if defined(CONFIG_RTC) || defined(CONFIG_RTC_MODULE) | ||
34 | |||
35 | #include <linux/mc146818rtc.h> | ||
36 | |||
37 | #define RTC_FREQ 1024 /* default frequency */ | ||
38 | #define NANO_SEC 1000000000L /* 10^9 in sec */ | ||
39 | |||
40 | /* | ||
41 | * prototypes | ||
42 | */ | ||
43 | static int rtctimer_open(snd_timer_t *t); | ||
44 | static int rtctimer_close(snd_timer_t *t); | ||
45 | static int rtctimer_start(snd_timer_t *t); | ||
46 | static int rtctimer_stop(snd_timer_t *t); | ||
47 | |||
48 | |||
49 | /* | ||
50 | * The hardware dependent description for this timer. | ||
51 | */ | ||
52 | static struct _snd_timer_hardware rtc_hw = { | ||
53 | .flags = SNDRV_TIMER_HW_FIRST|SNDRV_TIMER_HW_AUTO, | ||
54 | .ticks = 100000000L, /* FIXME: XXX */ | ||
55 | .open = rtctimer_open, | ||
56 | .close = rtctimer_close, | ||
57 | .start = rtctimer_start, | ||
58 | .stop = rtctimer_stop, | ||
59 | }; | ||
60 | |||
61 | static int rtctimer_freq = RTC_FREQ; /* frequency */ | ||
62 | static snd_timer_t *rtctimer; | ||
63 | static atomic_t rtc_inc = ATOMIC_INIT(0); | ||
64 | static rtc_task_t rtc_task; | ||
65 | |||
66 | |||
67 | static int | ||
68 | rtctimer_open(snd_timer_t *t) | ||
69 | { | ||
70 | int err; | ||
71 | |||
72 | err = rtc_register(&rtc_task); | ||
73 | if (err < 0) | ||
74 | return err; | ||
75 | t->private_data = &rtc_task; | ||
76 | return 0; | ||
77 | } | ||
78 | |||
79 | static int | ||
80 | rtctimer_close(snd_timer_t *t) | ||
81 | { | ||
82 | rtc_task_t *rtc = t->private_data; | ||
83 | if (rtc) { | ||
84 | rtc_unregister(rtc); | ||
85 | t->private_data = NULL; | ||
86 | } | ||
87 | return 0; | ||
88 | } | ||
89 | |||
90 | static int | ||
91 | rtctimer_start(snd_timer_t *timer) | ||
92 | { | ||
93 | rtc_task_t *rtc = timer->private_data; | ||
94 | snd_assert(rtc != NULL, return -EINVAL); | ||
95 | rtc_control(rtc, RTC_IRQP_SET, rtctimer_freq); | ||
96 | rtc_control(rtc, RTC_PIE_ON, 0); | ||
97 | atomic_set(&rtc_inc, 0); | ||
98 | return 0; | ||
99 | } | ||
100 | |||
101 | static int | ||
102 | rtctimer_stop(snd_timer_t *timer) | ||
103 | { | ||
104 | rtc_task_t *rtc = timer->private_data; | ||
105 | snd_assert(rtc != NULL, return -EINVAL); | ||
106 | rtc_control(rtc, RTC_PIE_OFF, 0); | ||
107 | return 0; | ||
108 | } | ||
109 | |||
110 | /* | ||
111 | * interrupt | ||
112 | */ | ||
113 | static void rtctimer_interrupt(void *private_data) | ||
114 | { | ||
115 | int ticks; | ||
116 | |||
117 | atomic_inc(&rtc_inc); | ||
118 | ticks = atomic_read(&rtc_inc); | ||
119 | snd_timer_interrupt((snd_timer_t*)private_data, ticks); | ||
120 | atomic_sub(ticks, &rtc_inc); | ||
121 | } | ||
122 | |||
123 | |||
124 | /* | ||
125 | * ENTRY functions | ||
126 | */ | ||
127 | static int __init rtctimer_init(void) | ||
128 | { | ||
129 | int order, err; | ||
130 | snd_timer_t *timer; | ||
131 | |||
132 | if (rtctimer_freq < 2 || rtctimer_freq > 8192) { | ||
133 | snd_printk(KERN_ERR "rtctimer: invalid frequency %d\n", rtctimer_freq); | ||
134 | return -EINVAL; | ||
135 | } | ||
136 | for (order = 1; rtctimer_freq > order; order <<= 1) | ||
137 | ; | ||
138 | if (rtctimer_freq != order) { | ||
139 | snd_printk(KERN_ERR "rtctimer: invalid frequency %d\n", rtctimer_freq); | ||
140 | return -EINVAL; | ||
141 | } | ||
142 | |||
143 | /* Create a new timer and set up the fields */ | ||
144 | err = snd_timer_global_new("rtc", SNDRV_TIMER_GLOBAL_RTC, &timer); | ||
145 | if (err < 0) | ||
146 | return err; | ||
147 | |||
148 | strcpy(timer->name, "RTC timer"); | ||
149 | timer->hw = rtc_hw; | ||
150 | timer->hw.resolution = NANO_SEC / rtctimer_freq; | ||
151 | |||
152 | /* set up RTC callback */ | ||
153 | rtc_task.func = rtctimer_interrupt; | ||
154 | rtc_task.private_data = timer; | ||
155 | |||
156 | err = snd_timer_global_register(timer); | ||
157 | if (err < 0) { | ||
158 | snd_timer_global_free(timer); | ||
159 | return err; | ||
160 | } | ||
161 | rtctimer = timer; /* remember this */ | ||
162 | |||
163 | return 0; | ||
164 | } | ||
165 | |||
166 | static void __exit rtctimer_exit(void) | ||
167 | { | ||
168 | if (rtctimer) { | ||
169 | snd_timer_global_unregister(rtctimer); | ||
170 | rtctimer = NULL; | ||
171 | } | ||
172 | } | ||
173 | |||
174 | |||
175 | /* | ||
176 | * exported stuff | ||
177 | */ | ||
178 | module_init(rtctimer_init) | ||
179 | module_exit(rtctimer_exit) | ||
180 | |||
181 | module_param(rtctimer_freq, int, 0444); | ||
182 | MODULE_PARM_DESC(rtctimer_freq, "timer frequency in Hz"); | ||
183 | |||
184 | MODULE_LICENSE("GPL"); | ||
185 | |||
186 | MODULE_ALIAS("snd-timer-" __stringify(SNDRV_TIMER_GLOBAL_RTC)); | ||
187 | |||
188 | #endif /* CONFIG_RTC || CONFIG_RTC_MODULE */ | ||