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-rw-r--r--arch/blackfin/mach-bf527/cpu.c161
1 files changed, 161 insertions, 0 deletions
diff --git a/arch/blackfin/mach-bf527/cpu.c b/arch/blackfin/mach-bf527/cpu.c
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1/*
2 * File: arch/blackfin/mach-bf527/cpu.c
3 * Based on: arch/blackfin/mach-bf537/cpu.c
4 * Author: michael.kang@analog.com
5 *
6 * Created:
7 * Description: clock scaling for the bf527
8 *
9 * Modified:
10 * Copyright 2004-2007 Analog Devices Inc.
11 *
12 * Bugs: Enter bugs at http://blackfin.uclinux.org/
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, see the file COPYING, or write
26 * to the Free Software Foundation, Inc.,
27 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
28 */
29
30#include <linux/kernel.h>
31#include <linux/types.h>
32#include <linux/init.h>
33#include <linux/cpufreq.h>
34#include <asm/dpmc.h>
35#include <linux/fs.h>
36#include <asm/bfin-global.h>
37
38/* CONFIG_CLKIN_HZ=11059200 */
39#define VCO5 (CONFIG_CLKIN_HZ*45) /*497664000 */
40#define VCO4 (CONFIG_CLKIN_HZ*36) /*398131200 */
41#define VCO3 (CONFIG_CLKIN_HZ*27) /*298598400 */
42#define VCO2 (CONFIG_CLKIN_HZ*18) /*199065600 */
43#define VCO1 (CONFIG_CLKIN_HZ*9) /*99532800 */
44#define VCO(x) VCO##x
45
46#define MFREQ(x) {VCO(x), VCO(x)/4}, {VCO(x), VCO(x)/2}, {VCO(x), VCO(x)}
47/* frequency */
48static struct cpufreq_frequency_table bf527_freq_table[] = {
49 MFREQ(1),
50 MFREQ(3),
51 {VCO4, VCO4 / 2}, {VCO4, VCO4},
52 MFREQ(5),
53 {0, CPUFREQ_TABLE_END},
54};
55
56/*
57 * dpmc_fops->ioctl()
58 * static int dpmc_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
59 */
60static int bf527_getfreq(unsigned int cpu)
61{
62 unsigned long cclk_mhz;
63
64 /* The driver only support single cpu */
65 if (cpu == 0)
66 dpmc_fops.ioctl(NULL, NULL, IOCTL_GET_CORECLOCK, &cclk_mhz);
67 else
68 cclk_mhz = -1;
69
70 return cclk_mhz;
71}
72
73static int bf527_target(struct cpufreq_policy *policy,
74 unsigned int target_freq, unsigned int relation)
75{
76 unsigned long cclk_mhz;
77 unsigned long vco_mhz;
78 unsigned long flags;
79 unsigned int index;
80 struct cpufreq_freqs freqs;
81
82 if (cpufreq_frequency_table_target
83 (policy, bf527_freq_table, target_freq, relation, &index))
84 return -EINVAL;
85
86 cclk_mhz = bf527_freq_table[index].frequency;
87 vco_mhz = bf527_freq_table[index].index;
88
89 dpmc_fops.ioctl(NULL, NULL, IOCTL_CHANGE_FREQUENCY, &vco_mhz);
90 freqs.old = bf527_getfreq(0);
91 freqs.new = cclk_mhz;
92 freqs.cpu = 0;
93
94 pr_debug
95 ("cclk begin change to cclk %d,vco=%d,index=%d,target=%d,oldfreq=%d\n",
96 cclk_mhz, vco_mhz, index, target_freq, freqs.old);
97
98 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
99 local_irq_save(flags);
100 dpmc_fops.ioctl(NULL, NULL, IOCTL_SET_CCLK, &cclk_mhz);
101 local_irq_restore(flags);
102 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
103
104 vco_mhz = get_vco();
105 cclk_mhz = get_cclk();
106 return 0;
107}
108
109/* make sure that only the "userspace" governor is run -- anything else wouldn't make sense on
110 * this platform, anyway.
111 */
112static int bf527_verify_speed(struct cpufreq_policy *policy)
113{
114 return cpufreq_frequency_table_verify(policy, &bf527_freq_table);
115}
116
117static int __init __bf527_cpu_init(struct cpufreq_policy *policy)
118{
119 if (policy->cpu != 0)
120 return -EINVAL;
121
122 policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
123
124 policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
125 /*Now ,only support one cpu */
126 policy->cur = bf527_getfreq(0);
127 cpufreq_frequency_table_get_attr(bf527_freq_table, policy->cpu);
128 return cpufreq_frequency_table_cpuinfo(policy, bf527_freq_table);
129}
130
131static struct freq_attr *bf527_freq_attr[] = {
132 &cpufreq_freq_attr_scaling_available_freqs,
133 NULL,
134};
135
136static struct cpufreq_driver bf527_driver = {
137 .verify = bf527_verify_speed,
138 .target = bf527_target,
139 .get = bf527_getfreq,
140 .init = __bf527_cpu_init,
141 .name = "bf527",
142 .owner = THIS_MODULE,
143 .attr = bf527_freq_attr,
144};
145
146static int __init bf527_cpu_init(void)
147{
148 return cpufreq_register_driver(&bf527_driver);
149}
150
151static void __exit bf527_cpu_exit(void)
152{
153 cpufreq_unregister_driver(&bf527_driver);
154}
155
156MODULE_AUTHOR("Mickael Kang");
157MODULE_DESCRIPTION("cpufreq driver for bf527 CPU");
158MODULE_LICENSE("GPL");
159
160module_init(bf527_cpu_init);
161module_exit(bf527_cpu_exit);