Annotation of prex-old/dev/power/cpufreq.c, Revision 1.1.1.1
1.1 nbrk 1: /*-
2: * Copyright (c) 2007, Kohsuke Ohtani
3: * All rights reserved.
4: *
5: * Redistribution and use in source and binary forms, with or without
6: * modification, are permitted provided that the following conditions
7: * are met:
8: * 1. Redistributions of source code must retain the above copyright
9: * notice, this list of conditions and the following disclaimer.
10: * 2. Redistributions in binary form must reproduce the above copyright
11: * notice, this list of conditions and the following disclaimer in the
12: * documentation and/or other materials provided with the distribution.
13: * 3. Neither the name of the author nor the names of any co-contributors
14: * may be used to endorse or promote products derived from this software
15: * without specific prior written permission.
16: *
17: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20: * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27: * SUCH DAMAGE.
28: */
29:
30: /*
31: * cpufreq.c - CPU frequency control
32: */
33:
34: #include <sys/ioctl.h>
35: #include <driver.h>
36: #include <pm.h>
37: #include "dvs.h"
38:
39: /* #define DEBUG_CPUFREQ 1 */
40:
41: #ifdef DEBUG_CPUFREQ
42: #define cf_printf(fmt, args...) printk("cpufreq: " fmt, ## args)
43: #else
44: #define cf_printf(fmt...) do {} while (0)
45: #endif
46:
47: static int cpufreq_open(device_t dev, int mode);
48: static int cpufreq_ioctl(device_t dev, int cmd, u_long arg);
49: static int cpufreq_close(device_t dev);
50: static int cpufreq_init(void);
51:
52: /*
53: * Driver structure
54: */
55: struct driver cpufreq_drv = {
56: /* name */ "CPU Frequency Control",
57: /* order */ 3, /* Must larger than pm driver */
58: /* init */ cpufreq_init,
59: };
60:
61: static struct devio cpufreq_io = {
62: /* open */ cpufreq_open,
63: /* close */ cpufreq_close,
64: /* read */ NULL,
65: /* write */ NULL,
66: /* ioctl */ cpufreq_ioctl,
67: /* event */ NULL,
68: };
69:
70: static device_t cpufreq_dev; /* Device object */
71:
72: /*
73: * Frequecy control policy
74: */
75: static int cpufreq_policy;
76:
77: static int
78: cpufreq_open(device_t dev, int mode)
79: {
80:
81: return 0;
82: }
83:
84: static int
85: cpufreq_close(device_t dev)
86: {
87:
88: return 0;
89: }
90:
91: static int
92: cpufreq_ioctl(device_t dev, int cmd, u_long arg)
93: {
94:
95: return 0;
96: }
97:
98: void
99: cpufreq_setpolicy(int policy)
100: {
101:
102: switch (cpufreq_policy) {
103: case CPUFREQ_ONDEMAND:
104: if (policy == PM_POWERSAVE)
105: dvs_enable();
106: else
107: dvs_disable();
108:
109: break;
110: case CPUFREQ_MAXSPEED:
111: break;
112: case CPUFREQ_MINSPEED:
113: break;
114: }
115: }
116:
117: static int
118: cpufreq_init(void)
119: {
120: int policy;
121:
122: /* Create device object */
123: cpufreq_dev = device_create(&cpufreq_io, "cpufreq", DF_CHR);
124: ASSERT(cpufreq_dev);
125:
126: dvs_init();
127:
128: policy = pm_getpolicy();
129: if (policy == PM_POWERSAVE)
130: dvs_enable();
131: return 0;
132: }
133:
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