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1/*
2 * Cpufreq driver for the loongson-2 processors
3 *
4 * The 2E revision of loongson processor not support this feature.
5 *
6 * Copyright (C) 2006 - 2008 Lemote Inc. & Institute of Computing Technology
7 * Author: Yanhua, yanh@lemote.com
8 *
9 * This file is subject to the terms and conditions of the GNU General Public
10 * License. See the file "COPYING" in the main directory of this archive
11 * for more details.
12 */
13
14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16#include <linux/cpufreq.h>
17#include <linux/module.h>
18#include <linux/err.h>
19#include <linux/delay.h>
20#include <linux/platform_device.h>
21
22#include <asm/idle.h>
23
24#include <asm/mach-loongson2ef/loongson.h>
25
26static uint nowait;
27
28static void (*saved_cpu_wait) (void);
29
30static int loongson2_cpu_freq_notifier(struct notifier_block *nb,
31 unsigned long val, void *data);
32
33static struct notifier_block loongson2_cpufreq_notifier_block = {
34 .notifier_call = loongson2_cpu_freq_notifier
35};
36
37static int loongson2_cpu_freq_notifier(struct notifier_block *nb,
38 unsigned long val, void *data)
39{
40 if (val == CPUFREQ_POSTCHANGE)
41 current_cpu_data.udelay_val = loops_per_jiffy;
42
43 return 0;
44}
45
46/*
47 * Here we notify other drivers of the proposed change and the final change.
48 */
49static int loongson2_cpufreq_target(struct cpufreq_policy *policy,
50 unsigned int index)
51{
52 unsigned int freq;
53
54 freq =
55 ((cpu_clock_freq / 1000) *
56 loongson2_clockmod_table[index].driver_data) / 8;
57
58 /* setting the cpu frequency */
59 loongson2_cpu_set_rate(freq);
60
61 return 0;
62}
63
64static int loongson2_cpufreq_cpu_init(struct cpufreq_policy *policy)
65{
66 int i;
67 unsigned long rate;
68 int ret;
69
70 rate = cpu_clock_freq / 1000;
71 if (!rate)
72 return -EINVAL;
73
74 /* clock table init */
75 for (i = 2;
76 (loongson2_clockmod_table[i].frequency != CPUFREQ_TABLE_END);
77 i++)
78 loongson2_clockmod_table[i].frequency = (rate * i) / 8;
79
80 ret = loongson2_cpu_set_rate(rate);
81 if (ret)
82 return ret;
83
84 cpufreq_generic_init(policy, &loongson2_clockmod_table[0], 0);
85 return 0;
86}
87
88static int loongson2_cpufreq_exit(struct cpufreq_policy *policy)
89{
90 return 0;
91}
92
93static struct cpufreq_driver loongson2_cpufreq_driver = {
94 .name = "loongson2",
95 .init = loongson2_cpufreq_cpu_init,
96 .verify = cpufreq_generic_frequency_table_verify,
97 .target_index = loongson2_cpufreq_target,
98 .get = cpufreq_generic_get,
99 .exit = loongson2_cpufreq_exit,
100 .attr = cpufreq_generic_attr,
101};
102
103static const struct platform_device_id platform_device_ids[] = {
104 {
105 .name = "loongson2_cpufreq",
106 },
107 {}
108};
109
110MODULE_DEVICE_TABLE(platform, platform_device_ids);
111
112static struct platform_driver platform_driver = {
113 .driver = {
114 .name = "loongson2_cpufreq",
115 },
116 .id_table = platform_device_ids,
117};
118
119/*
120 * This is the simple version of Loongson-2 wait, Maybe we need do this in
121 * interrupt disabled context.
122 */
123
124static DEFINE_SPINLOCK(loongson2_wait_lock);
125
126static void loongson2_cpu_wait(void)
127{
128 unsigned long flags;
129 u32 cpu_freq;
130
131 spin_lock_irqsave(&loongson2_wait_lock, flags);
132 cpu_freq = readl(LOONGSON_CHIPCFG);
133 /* Put CPU into wait mode */
134 writel(readl(LOONGSON_CHIPCFG) & ~0x7, LOONGSON_CHIPCFG);
135 /* Restore CPU state */
136 writel(cpu_freq, LOONGSON_CHIPCFG);
137 spin_unlock_irqrestore(&loongson2_wait_lock, flags);
138 local_irq_enable();
139}
140
141static int __init cpufreq_init(void)
142{
143 int ret;
144
145 /* Register platform stuff */
146 ret = platform_driver_register(&platform_driver);
147 if (ret)
148 return ret;
149
150 pr_info("Loongson-2F CPU frequency driver\n");
151
152 cpufreq_register_notifier(&loongson2_cpufreq_notifier_block,
153 CPUFREQ_TRANSITION_NOTIFIER);
154
155 ret = cpufreq_register_driver(&loongson2_cpufreq_driver);
156
157 if (!ret && !nowait) {
158 saved_cpu_wait = cpu_wait;
159 cpu_wait = loongson2_cpu_wait;
160 }
161
162 return ret;
163}
164
165static void __exit cpufreq_exit(void)
166{
167 if (!nowait && saved_cpu_wait)
168 cpu_wait = saved_cpu_wait;
169 cpufreq_unregister_driver(&loongson2_cpufreq_driver);
170 cpufreq_unregister_notifier(&loongson2_cpufreq_notifier_block,
171 CPUFREQ_TRANSITION_NOTIFIER);
172
173 platform_driver_unregister(&platform_driver);
174}
175
176module_init(cpufreq_init);
177module_exit(cpufreq_exit);
178
179module_param(nowait, uint, 0644);
180MODULE_PARM_DESC(nowait, "Disable Loongson-2F specific wait");
181
182MODULE_AUTHOR("Yanhua <yanh@lemote.com>");
183MODULE_DESCRIPTION("cpufreq driver for Loongson2F");
184MODULE_LICENSE("GPL");
1/*
2 * Cpufreq driver for the loongson-2 processors
3 *
4 * The 2E revision of loongson processor not support this feature.
5 *
6 * Copyright (C) 2006 - 2008 Lemote Inc. & Institute of Computing Technology
7 * Author: Yanhua, yanh@lemote.com
8 *
9 * This file is subject to the terms and conditions of the GNU General Public
10 * License. See the file "COPYING" in the main directory of this archive
11 * for more details.
12 */
13
14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16#include <linux/cpufreq.h>
17#include <linux/module.h>
18#include <linux/err.h>
19#include <linux/sched.h> /* set_cpus_allowed() */
20#include <linux/delay.h>
21#include <linux/platform_device.h>
22
23#include <asm/idle.h>
24
25#include <asm/mach-loongson2ef/loongson.h>
26
27static uint nowait;
28
29static void (*saved_cpu_wait) (void);
30
31static int loongson2_cpu_freq_notifier(struct notifier_block *nb,
32 unsigned long val, void *data);
33
34static struct notifier_block loongson2_cpufreq_notifier_block = {
35 .notifier_call = loongson2_cpu_freq_notifier
36};
37
38static int loongson2_cpu_freq_notifier(struct notifier_block *nb,
39 unsigned long val, void *data)
40{
41 if (val == CPUFREQ_POSTCHANGE)
42 current_cpu_data.udelay_val = loops_per_jiffy;
43
44 return 0;
45}
46
47/*
48 * Here we notify other drivers of the proposed change and the final change.
49 */
50static int loongson2_cpufreq_target(struct cpufreq_policy *policy,
51 unsigned int index)
52{
53 unsigned int freq;
54
55 freq =
56 ((cpu_clock_freq / 1000) *
57 loongson2_clockmod_table[index].driver_data) / 8;
58
59 /* setting the cpu frequency */
60 loongson2_cpu_set_rate(freq);
61
62 return 0;
63}
64
65static int loongson2_cpufreq_cpu_init(struct cpufreq_policy *policy)
66{
67 int i;
68 unsigned long rate;
69 int ret;
70
71 rate = cpu_clock_freq / 1000;
72 if (!rate)
73 return -EINVAL;
74
75 /* clock table init */
76 for (i = 2;
77 (loongson2_clockmod_table[i].frequency != CPUFREQ_TABLE_END);
78 i++)
79 loongson2_clockmod_table[i].frequency = (rate * i) / 8;
80
81 ret = loongson2_cpu_set_rate(rate);
82 if (ret)
83 return ret;
84
85 cpufreq_generic_init(policy, &loongson2_clockmod_table[0], 0);
86 return 0;
87}
88
89static int loongson2_cpufreq_exit(struct cpufreq_policy *policy)
90{
91 return 0;
92}
93
94static struct cpufreq_driver loongson2_cpufreq_driver = {
95 .name = "loongson2",
96 .init = loongson2_cpufreq_cpu_init,
97 .verify = cpufreq_generic_frequency_table_verify,
98 .target_index = loongson2_cpufreq_target,
99 .get = cpufreq_generic_get,
100 .exit = loongson2_cpufreq_exit,
101 .attr = cpufreq_generic_attr,
102};
103
104static const struct platform_device_id platform_device_ids[] = {
105 {
106 .name = "loongson2_cpufreq",
107 },
108 {}
109};
110
111MODULE_DEVICE_TABLE(platform, platform_device_ids);
112
113static struct platform_driver platform_driver = {
114 .driver = {
115 .name = "loongson2_cpufreq",
116 },
117 .id_table = platform_device_ids,
118};
119
120/*
121 * This is the simple version of Loongson-2 wait, Maybe we need do this in
122 * interrupt disabled context.
123 */
124
125static DEFINE_SPINLOCK(loongson2_wait_lock);
126
127static void loongson2_cpu_wait(void)
128{
129 unsigned long flags;
130 u32 cpu_freq;
131
132 spin_lock_irqsave(&loongson2_wait_lock, flags);
133 cpu_freq = readl(LOONGSON_CHIPCFG);
134 /* Put CPU into wait mode */
135 writel(readl(LOONGSON_CHIPCFG) & ~0x7, LOONGSON_CHIPCFG);
136 /* Restore CPU state */
137 writel(cpu_freq, LOONGSON_CHIPCFG);
138 spin_unlock_irqrestore(&loongson2_wait_lock, flags);
139 local_irq_enable();
140}
141
142static int __init cpufreq_init(void)
143{
144 int ret;
145
146 /* Register platform stuff */
147 ret = platform_driver_register(&platform_driver);
148 if (ret)
149 return ret;
150
151 pr_info("Loongson-2F CPU frequency driver\n");
152
153 cpufreq_register_notifier(&loongson2_cpufreq_notifier_block,
154 CPUFREQ_TRANSITION_NOTIFIER);
155
156 ret = cpufreq_register_driver(&loongson2_cpufreq_driver);
157
158 if (!ret && !nowait) {
159 saved_cpu_wait = cpu_wait;
160 cpu_wait = loongson2_cpu_wait;
161 }
162
163 return ret;
164}
165
166static void __exit cpufreq_exit(void)
167{
168 if (!nowait && saved_cpu_wait)
169 cpu_wait = saved_cpu_wait;
170 cpufreq_unregister_driver(&loongson2_cpufreq_driver);
171 cpufreq_unregister_notifier(&loongson2_cpufreq_notifier_block,
172 CPUFREQ_TRANSITION_NOTIFIER);
173
174 platform_driver_unregister(&platform_driver);
175}
176
177module_init(cpufreq_init);
178module_exit(cpufreq_exit);
179
180module_param(nowait, uint, 0644);
181MODULE_PARM_DESC(nowait, "Disable Loongson-2F specific wait");
182
183MODULE_AUTHOR("Yanhua <yanh@lemote.com>");
184MODULE_DESCRIPTION("cpufreq driver for Loongson2F");
185MODULE_LICENSE("GPL");