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75722d39 BH |
1 | #include <linux/types.h> |
2 | #include <linux/errno.h> | |
3 | #include <linux/kernel.h> | |
4 | #include <linux/delay.h> | |
5 | #include <linux/slab.h> | |
6 | #include <linux/init.h> | |
7 | #include <linux/wait.h> | |
8 | #include <linux/cpufreq.h> | |
9 | ||
b55fafc5 BH |
10 | #include <asm/prom.h> |
11 | ||
75722d39 BH |
12 | #include "windfarm.h" |
13 | ||
14 | #define VERSION "0.3" | |
15 | ||
16 | static int clamped; | |
17 | static struct wf_control *clamp_control; | |
18 | ||
19 | static int clamp_notifier_call(struct notifier_block *self, | |
20 | unsigned long event, void *data) | |
21 | { | |
22 | struct cpufreq_policy *p = data; | |
23 | unsigned long max_freq; | |
24 | ||
25 | if (event != CPUFREQ_ADJUST) | |
26 | return 0; | |
27 | ||
28 | max_freq = clamped ? (p->cpuinfo.min_freq) : (p->cpuinfo.max_freq); | |
29 | cpufreq_verify_within_limits(p, 0, max_freq); | |
30 | ||
31 | return 0; | |
32 | } | |
33 | ||
34 | static struct notifier_block clamp_notifier = { | |
35 | .notifier_call = clamp_notifier_call, | |
36 | }; | |
37 | ||
38 | static int clamp_set(struct wf_control *ct, s32 value) | |
39 | { | |
40 | if (value) | |
41 | printk(KERN_INFO "windfarm: Clamping CPU frequency to " | |
42 | "minimum !\n"); | |
43 | else | |
44 | printk(KERN_INFO "windfarm: CPU frequency unclamped !\n"); | |
45 | clamped = value; | |
46 | cpufreq_update_policy(0); | |
47 | return 0; | |
48 | } | |
49 | ||
50 | static int clamp_get(struct wf_control *ct, s32 *value) | |
51 | { | |
52 | *value = clamped; | |
53 | return 0; | |
54 | } | |
55 | ||
56 | static s32 clamp_min(struct wf_control *ct) | |
57 | { | |
58 | return 0; | |
59 | } | |
60 | ||
61 | static s32 clamp_max(struct wf_control *ct) | |
62 | { | |
63 | return 1; | |
64 | } | |
65 | ||
66 | static struct wf_control_ops clamp_ops = { | |
67 | .set_value = clamp_set, | |
68 | .get_value = clamp_get, | |
69 | .get_min = clamp_min, | |
70 | .get_max = clamp_max, | |
71 | .owner = THIS_MODULE, | |
72 | }; | |
73 | ||
74 | static int __init wf_cpufreq_clamp_init(void) | |
75 | { | |
76 | struct wf_control *clamp; | |
77 | ||
b55fafc5 BH |
78 | /* Don't register on old machines that use therm_pm72 for now */ |
79 | if (machine_is_compatible("PowerMac7,2") || | |
80 | machine_is_compatible("PowerMac7,3") || | |
81 | machine_is_compatible("RackMac3,1")) | |
82 | return -ENODEV; | |
83 | ||
75722d39 BH |
84 | clamp = kmalloc(sizeof(struct wf_control), GFP_KERNEL); |
85 | if (clamp == NULL) | |
86 | return -ENOMEM; | |
87 | cpufreq_register_notifier(&clamp_notifier, CPUFREQ_POLICY_NOTIFIER); | |
88 | clamp->ops = &clamp_ops; | |
89 | clamp->name = "cpufreq-clamp"; | |
90 | if (wf_register_control(clamp)) | |
91 | goto fail; | |
92 | clamp_control = clamp; | |
93 | return 0; | |
94 | fail: | |
95 | kfree(clamp); | |
96 | return -ENODEV; | |
97 | } | |
98 | ||
99 | static void __exit wf_cpufreq_clamp_exit(void) | |
100 | { | |
101 | if (clamp_control) | |
102 | wf_unregister_control(clamp_control); | |
103 | } | |
104 | ||
105 | ||
106 | module_init(wf_cpufreq_clamp_init); | |
107 | module_exit(wf_cpufreq_clamp_exit); | |
108 | ||
109 | MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); | |
110 | MODULE_DESCRIPTION("CPU frequency clamp for PowerMacs thermal control"); | |
111 | MODULE_LICENSE("GPL"); | |
112 |