Root/
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 <linux/init.h> |
24 | #include <linux/interrupt.h> |
25 | #include <linux/moduleparam.h> |
26 | #include <linux/log2.h> |
27 | #include <sound/core.h> |
28 | #include <sound/timer.h> |
29 | |
30 | #if defined(CONFIG_RTC) || defined(CONFIG_RTC_MODULE) |
31 | |
32 | #include <linux/mc146818rtc.h> |
33 | |
34 | #define RTC_FREQ 1024 /* default frequency */ |
35 | #define NANO_SEC 1000000000L /* 10^9 in sec */ |
36 | |
37 | /* |
38 | * prototypes |
39 | */ |
40 | static int rtctimer_open(struct snd_timer *t); |
41 | static int rtctimer_close(struct snd_timer *t); |
42 | static int rtctimer_start(struct snd_timer *t); |
43 | static int rtctimer_stop(struct snd_timer *t); |
44 | |
45 | |
46 | /* |
47 | * The hardware dependent description for this timer. |
48 | */ |
49 | static struct snd_timer_hardware rtc_hw = { |
50 | .flags = SNDRV_TIMER_HW_AUTO | |
51 | SNDRV_TIMER_HW_FIRST | |
52 | SNDRV_TIMER_HW_TASKLET, |
53 | .ticks = 100000000L, /* FIXME: XXX */ |
54 | .open = rtctimer_open, |
55 | .close = rtctimer_close, |
56 | .start = rtctimer_start, |
57 | .stop = rtctimer_stop, |
58 | }; |
59 | |
60 | static int rtctimer_freq = RTC_FREQ; /* frequency */ |
61 | static struct snd_timer *rtctimer; |
62 | static struct tasklet_struct rtc_tasklet; |
63 | static rtc_task_t rtc_task; |
64 | |
65 | |
66 | static int |
67 | rtctimer_open(struct snd_timer *t) |
68 | { |
69 | int err; |
70 | |
71 | err = rtc_register(&rtc_task); |
72 | if (err < 0) |
73 | return err; |
74 | t->private_data = &rtc_task; |
75 | return 0; |
76 | } |
77 | |
78 | static int |
79 | rtctimer_close(struct snd_timer *t) |
80 | { |
81 | rtc_task_t *rtc = t->private_data; |
82 | if (rtc) { |
83 | rtc_unregister(rtc); |
84 | tasklet_kill(&rtc_tasklet); |
85 | t->private_data = NULL; |
86 | } |
87 | return 0; |
88 | } |
89 | |
90 | static int |
91 | rtctimer_start(struct snd_timer *timer) |
92 | { |
93 | rtc_task_t *rtc = timer->private_data; |
94 | if (snd_BUG_ON(!rtc)) |
95 | return -EINVAL; |
96 | rtc_control(rtc, RTC_IRQP_SET, rtctimer_freq); |
97 | rtc_control(rtc, RTC_PIE_ON, 0); |
98 | return 0; |
99 | } |
100 | |
101 | static int |
102 | rtctimer_stop(struct snd_timer *timer) |
103 | { |
104 | rtc_task_t *rtc = timer->private_data; |
105 | if (snd_BUG_ON(!rtc)) |
106 | return -EINVAL; |
107 | rtc_control(rtc, RTC_PIE_OFF, 0); |
108 | return 0; |
109 | } |
110 | |
111 | static void rtctimer_tasklet(unsigned long data) |
112 | { |
113 | snd_timer_interrupt((struct snd_timer *)data, 1); |
114 | } |
115 | |
116 | /* |
117 | * interrupt |
118 | */ |
119 | static void rtctimer_interrupt(void *private_data) |
120 | { |
121 | tasklet_schedule(private_data); |
122 | } |
123 | |
124 | |
125 | /* |
126 | * ENTRY functions |
127 | */ |
128 | static int __init rtctimer_init(void) |
129 | { |
130 | int err; |
131 | struct snd_timer *timer; |
132 | |
133 | if (rtctimer_freq < 2 || rtctimer_freq > 8192 || |
134 | !is_power_of_2(rtctimer_freq)) { |
135 | snd_printk(KERN_ERR "rtctimer: invalid frequency %d\n", |
136 | rtctimer_freq); |
137 | return -EINVAL; |
138 | } |
139 | |
140 | /* Create a new timer and set up the fields */ |
141 | err = snd_timer_global_new("rtc", SNDRV_TIMER_GLOBAL_RTC, &timer); |
142 | if (err < 0) |
143 | return err; |
144 | |
145 | timer->module = THIS_MODULE; |
146 | strcpy(timer->name, "RTC timer"); |
147 | timer->hw = rtc_hw; |
148 | timer->hw.resolution = NANO_SEC / rtctimer_freq; |
149 | |
150 | tasklet_init(&rtc_tasklet, rtctimer_tasklet, (unsigned long)timer); |
151 | |
152 | /* set up RTC callback */ |
153 | rtc_task.func = rtctimer_interrupt; |
154 | rtc_task.private_data = &rtc_tasklet; |
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_free(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 */ |
189 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9