cpufreq: remove policy->governor setting in drivers initialization
[linux-2.6.git] / arch / avr32 / mach-at32ap / cpufreq.c
1 /*
2  * Copyright (C) 2004-2007 Atmel Corporation
3  *
4  * Based on MIPS implementation arch/mips/kernel/time.c
5  *   Copyright 2001 MontaVista Software Inc.
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 version 2 as
9  * published by the Free Software Foundation.
10  */
11
12 /*#define DEBUG*/
13
14 #include <linux/kernel.h>
15 #include <linux/types.h>
16 #include <linux/init.h>
17 #include <linux/cpufreq.h>
18 #include <linux/io.h>
19 #include <linux/clk.h>
20 #include <linux/err.h>
21 #include <asm/system.h>
22
23 static struct clk *cpuclk;
24
25 static int at32_verify_speed(struct cpufreq_policy *policy)
26 {
27         if (policy->cpu != 0)
28                 return -EINVAL;
29
30         cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
31                         policy->cpuinfo.max_freq);
32         return 0;
33 }
34
35 static unsigned int at32_get_speed(unsigned int cpu)
36 {
37         /* No SMP support */
38         if (cpu)
39                 return 0;
40         return (unsigned int)((clk_get_rate(cpuclk) + 500) / 1000);
41 }
42
43 static int at32_set_target(struct cpufreq_policy *policy,
44                           unsigned int target_freq,
45                           unsigned int relation)
46 {
47         struct cpufreq_freqs freqs;
48         long freq;
49
50         /* Convert target_freq from kHz to Hz */
51         freq = clk_round_rate(cpuclk, target_freq * 1000);
52
53         /* Check if policy->min <= new_freq <= policy->max */
54         if(freq < (policy->min * 1000) || freq > (policy->max * 1000))
55                 return -EINVAL;
56
57         pr_debug("cpufreq: requested frequency %u Hz\n", target_freq * 1000);
58
59         freqs.old = at32_get_speed(0);
60         freqs.new = (freq + 500) / 1000;
61         freqs.cpu = 0;
62         freqs.flags = 0;
63
64         cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
65         clk_set_rate(cpuclk, freq);
66         cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
67
68         pr_debug("cpufreq: set frequency %lu Hz\n", freq);
69
70         return 0;
71 }
72
73 static int __init at32_cpufreq_driver_init(struct cpufreq_policy *policy)
74 {
75         if (policy->cpu != 0)
76                 return -EINVAL;
77
78         cpuclk = clk_get(NULL, "cpu");
79         if (IS_ERR(cpuclk)) {
80                 pr_debug("cpufreq: could not get CPU clk\n");
81                 return PTR_ERR(cpuclk);
82         }
83
84         policy->cpuinfo.min_freq = (clk_round_rate(cpuclk, 1) + 500) / 1000;
85         policy->cpuinfo.max_freq = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000;
86         policy->cpuinfo.transition_latency = 0;
87         policy->cur = at32_get_speed(0);
88         policy->min = policy->cpuinfo.min_freq;
89         policy->max = policy->cpuinfo.max_freq;
90
91         printk("cpufreq: AT32AP CPU frequency driver\n");
92
93         return 0;
94 }
95
96 static struct cpufreq_driver at32_driver = {
97         .name           = "at32ap",
98         .owner          = THIS_MODULE,
99         .init           = at32_cpufreq_driver_init,
100         .verify         = at32_verify_speed,
101         .target         = at32_set_target,
102         .get            = at32_get_speed,
103         .flags          = CPUFREQ_STICKY,
104 };
105
106 static int __init at32_cpufreq_init(void)
107 {
108         return cpufreq_register_driver(&at32_driver);
109 }
110 late_initcall(at32_cpufreq_init);