Pull bsp-removal into release branch
[linux-2.6] / drivers / macintosh / windfarm_cpufreq_clamp.c
1 #include <linux/config.h>
2 #include <linux/types.h>
3 #include <linux/errno.h>
4 #include <linux/kernel.h>
5 #include <linux/delay.h>
6 #include <linux/slab.h>
7 #include <linux/init.h>
8 #include <linux/wait.h>
9 #include <linux/cpufreq.h>
10
11 #include <asm/prom.h>
12
13 #include "windfarm.h"
14
15 #define VERSION "0.3"
16
17 static int clamped;
18 static struct wf_control *clamp_control;
19
20 static int clamp_notifier_call(struct notifier_block *self,
21                                unsigned long event, void *data)
22 {
23         struct cpufreq_policy *p = data;
24         unsigned long max_freq;
25
26         if (event != CPUFREQ_ADJUST)
27                 return 0;
28
29         max_freq = clamped ? (p->cpuinfo.min_freq) : (p->cpuinfo.max_freq);
30         cpufreq_verify_within_limits(p, 0, max_freq);
31
32         return 0;
33 }
34
35 static struct notifier_block clamp_notifier = {
36         .notifier_call = clamp_notifier_call,
37 };
38
39 static int clamp_set(struct wf_control *ct, s32 value)
40 {
41         if (value)
42                 printk(KERN_INFO "windfarm: Clamping CPU frequency to "
43                        "minimum !\n");
44         else
45                 printk(KERN_INFO "windfarm: CPU frequency unclamped !\n");
46         clamped = value;
47         cpufreq_update_policy(0);
48         return 0;
49 }
50
51 static int clamp_get(struct wf_control *ct, s32 *value)
52 {
53         *value = clamped;
54         return 0;
55 }
56
57 static s32 clamp_min(struct wf_control *ct)
58 {
59         return 0;
60 }
61
62 static s32 clamp_max(struct wf_control *ct)
63 {
64         return 1;
65 }
66
67 static struct wf_control_ops clamp_ops = {
68         .set_value      = clamp_set,
69         .get_value      = clamp_get,
70         .get_min        = clamp_min,
71         .get_max        = clamp_max,
72         .owner          = THIS_MODULE,
73 };
74
75 static int __init wf_cpufreq_clamp_init(void)
76 {
77         struct wf_control *clamp;
78
79         /* Don't register on old machines that use therm_pm72 for now */
80         if (machine_is_compatible("PowerMac7,2") ||
81             machine_is_compatible("PowerMac7,3") ||
82             machine_is_compatible("RackMac3,1"))
83                 return -ENODEV;
84
85         clamp = kmalloc(sizeof(struct wf_control), GFP_KERNEL);
86         if (clamp == NULL)
87                 return -ENOMEM;
88         cpufreq_register_notifier(&clamp_notifier, CPUFREQ_POLICY_NOTIFIER);
89         clamp->ops = &clamp_ops;
90         clamp->name = "cpufreq-clamp";
91         if (wf_register_control(clamp))
92                 goto fail;
93         clamp_control = clamp;
94         return 0;
95  fail:
96         kfree(clamp);
97         return -ENODEV;
98 }
99
100 static void __exit wf_cpufreq_clamp_exit(void)
101 {
102         if (clamp_control)
103                 wf_unregister_control(clamp_control);
104 }
105
106
107 module_init(wf_cpufreq_clamp_init);
108 module_exit(wf_cpufreq_clamp_exit);
109
110 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
111 MODULE_DESCRIPTION("CPU frequency clamp for PowerMacs thermal control");
112 MODULE_LICENSE("GPL");
113