microblaze: uaccess: fix put_user and get_user macros
[linux-2.6.git] / sound / core / hrtimer.c
1 /*
2  * ALSA timer back-end using hrtimer
3  * Copyright (C) 2008 Takashi Iwai
4  *
5  *   This program is free software; you can redistribute it and/or modify
6  *   it under the terms of the GNU General Public License as published by
7  *   the Free Software Foundation; either version 2 of the License, or
8  *   (at your option) any later version.
9  *
10  *   This program is distributed in the hope that it will be useful,
11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  *   GNU General Public License for more details.
14  *
15  *   You should have received a copy of the GNU General Public License
16  *   along with this program; if not, write to the Free Software
17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
18  *
19  */
20
21 #include <linux/init.h>
22 #include <linux/module.h>
23 #include <linux/moduleparam.h>
24 #include <linux/hrtimer.h>
25 #include <sound/core.h>
26 #include <sound/timer.h>
27
28 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
29 MODULE_DESCRIPTION("ALSA hrtimer backend");
30 MODULE_LICENSE("GPL");
31
32 MODULE_ALIAS("snd-timer-" __stringify(SNDRV_TIMER_GLOBAL_HRTIMER));
33
34 #define NANO_SEC        1000000000UL    /* 10^9 in sec */
35 static unsigned int resolution;
36
37 struct snd_hrtimer {
38         struct snd_timer *timer;
39         struct hrtimer hrt;
40         atomic_t running;
41 };
42
43 static enum hrtimer_restart snd_hrtimer_callback(struct hrtimer *hrt)
44 {
45         struct snd_hrtimer *stime = container_of(hrt, struct snd_hrtimer, hrt);
46         struct snd_timer *t = stime->timer;
47
48         if (!atomic_read(&stime->running))
49                 return HRTIMER_NORESTART;
50
51         hrtimer_forward_now(hrt, ns_to_ktime(t->sticks * resolution));
52         snd_timer_interrupt(stime->timer, t->sticks);
53
54         if (!atomic_read(&stime->running))
55                 return HRTIMER_NORESTART;
56         return HRTIMER_RESTART;
57 }
58
59 static int snd_hrtimer_open(struct snd_timer *t)
60 {
61         struct snd_hrtimer *stime;
62
63         stime = kmalloc(sizeof(*stime), GFP_KERNEL);
64         if (!stime)
65                 return -ENOMEM;
66         hrtimer_init(&stime->hrt, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
67         stime->timer = t;
68         stime->hrt.function = snd_hrtimer_callback;
69         atomic_set(&stime->running, 0);
70         t->private_data = stime;
71         return 0;
72 }
73
74 static int snd_hrtimer_close(struct snd_timer *t)
75 {
76         struct snd_hrtimer *stime = t->private_data;
77
78         if (stime) {
79                 hrtimer_cancel(&stime->hrt);
80                 kfree(stime);
81                 t->private_data = NULL;
82         }
83         return 0;
84 }
85
86 static int snd_hrtimer_start(struct snd_timer *t)
87 {
88         struct snd_hrtimer *stime = t->private_data;
89
90         atomic_set(&stime->running, 0);
91         hrtimer_cancel(&stime->hrt);
92         hrtimer_start(&stime->hrt, ns_to_ktime(t->sticks * resolution),
93                       HRTIMER_MODE_REL);
94         atomic_set(&stime->running, 1);
95         return 0;
96 }
97
98 static int snd_hrtimer_stop(struct snd_timer *t)
99 {
100         struct snd_hrtimer *stime = t->private_data;
101         atomic_set(&stime->running, 0);
102         return 0;
103 }
104
105 static struct snd_timer_hardware hrtimer_hw = {
106         .flags =        SNDRV_TIMER_HW_AUTO,
107         .open =         snd_hrtimer_open,
108         .close =        snd_hrtimer_close,
109         .start =        snd_hrtimer_start,
110         .stop =         snd_hrtimer_stop,
111 };
112
113 /*
114  * entry functions
115  */
116
117 static struct snd_timer *mytimer;
118
119 static int __init snd_hrtimer_init(void)
120 {
121         struct snd_timer *timer;
122         struct timespec tp;
123         int err;
124
125         hrtimer_get_res(CLOCK_MONOTONIC, &tp);
126         if (tp.tv_sec > 0 || !tp.tv_nsec) {
127                 snd_printk(KERN_ERR
128                            "snd-hrtimer: Invalid resolution %u.%09u",
129                            (unsigned)tp.tv_sec, (unsigned)tp.tv_nsec);
130                 return -EINVAL;
131         }
132         resolution = tp.tv_nsec;
133
134         /* Create a new timer and set up the fields */
135         err = snd_timer_global_new("hrtimer", SNDRV_TIMER_GLOBAL_HRTIMER,
136                                    &timer);
137         if (err < 0)
138                 return err;
139
140         timer->module = THIS_MODULE;
141         strcpy(timer->name, "HR timer");
142         timer->hw = hrtimer_hw;
143         timer->hw.resolution = resolution;
144         timer->hw.ticks = NANO_SEC / resolution;
145
146         err = snd_timer_global_register(timer);
147         if (err < 0) {
148                 snd_timer_global_free(timer);
149                 return err;
150         }
151         mytimer = timer; /* remember this */
152
153         return 0;
154 }
155
156 static void __exit snd_hrtimer_exit(void)
157 {
158         if (mytimer) {
159                 snd_timer_global_free(mytimer);
160                 mytimer = NULL;
161         }
162 }
163
164 module_init(snd_hrtimer_init);
165 module_exit(snd_hrtimer_exit);