Eric Lee / smarc-fsl-linux-kernel

Blame view

drivers/macintosh/windfarm_cpufreq_clamp.c 2.14 KB
edit raw normal view history
75722d399   Benjamin Herrenschmidt   [PATCH] ppc64: Th... 
1
2
3
4
5
6
7
8
 
  #include <linux/types.h>
  #include <linux/errno.h>
  #include <linux/kernel.h>
  #include <linux/delay.h>
  #include <linux/slab.h>
  #include <linux/init.h>
  #include <linux/wait.h>
  #include <linux/cpufreq.h>
b55fafc5a   Benjamin Herrenschmidt   [PATCH] powerpc: ... 
9
 
  #include <asm/prom.h>
75722d399   Benjamin Herrenschmidt   [PATCH] ppc64: Th... 
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
 
  #include "windfarm.h"
  
  #define VERSION "0.3"
  
  static int clamped;
  static struct wf_control *clamp_control;
  
  static int clamp_notifier_call(struct notifier_block *self,
  			       unsigned long event, void *data)
  {
  	struct cpufreq_policy *p = data;
  	unsigned long max_freq;
  
  	if (event != CPUFREQ_ADJUST)
  		return 0;
  
  	max_freq = clamped ? (p->cpuinfo.min_freq) : (p->cpuinfo.max_freq);
  	cpufreq_verify_within_limits(p, 0, max_freq);
  
  	return 0;
  }
  
  static struct notifier_block clamp_notifier = {
  	.notifier_call = clamp_notifier_call,
  };
  
  static int clamp_set(struct wf_control *ct, s32 value)
  {
  	if (value)
  		printk(KERN_INFO "windfarm: Clamping CPU frequency to "
  		       "minimum !
  ");
  	else
  		printk(KERN_INFO "windfarm: CPU frequency unclamped !
  ");
  	clamped = value;
  	cpufreq_update_policy(0);
  	return 0;
  }
  
  static int clamp_get(struct wf_control *ct, s32 *value)
  {
  	*value = clamped;
  	return 0;
  }
  
  static s32 clamp_min(struct wf_control *ct)
  {
  	return 0;
  }
  
  static s32 clamp_max(struct wf_control *ct)
  {
  	return 1;
  }
  
  static struct wf_control_ops clamp_ops = {
  	.set_value	= clamp_set,
  	.get_value	= clamp_get,
  	.get_min	= clamp_min,
  	.get_max	= clamp_max,
  	.owner		= THIS_MODULE,
  };
  
  static int __init wf_cpufreq_clamp_init(void)
  {
  	struct wf_control *clamp;
  
  	clamp = kmalloc(sizeof(struct wf_control), GFP_KERNEL);
  	if (clamp == NULL)
  		return -ENOMEM;
  	cpufreq_register_notifier(&clamp_notifier, CPUFREQ_POLICY_NOTIFIER);
  	clamp->ops = &clamp_ops;
  	clamp->name = "cpufreq-clamp";
  	if (wf_register_control(clamp))
  		goto fail;
  	clamp_control = clamp;
  	return 0;
   fail:
  	kfree(clamp);
  	return -ENODEV;
  }
  
  static void __exit wf_cpufreq_clamp_exit(void)
  {
  	if (clamp_control)
  		wf_unregister_control(clamp_control);
  }
  
  
  module_init(wf_cpufreq_clamp_init);
  module_exit(wf_cpufreq_clamp_exit);
  
  MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
  MODULE_DESCRIPTION("CPU frequency clamp for PowerMacs thermal control");
  MODULE_LICENSE("GPL");