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-rw-r--r--arch/arm/mach-s3c2410/cpu-freq.c157
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diff --git a/arch/arm/mach-s3c2410/cpu-freq.c b/arch/arm/mach-s3c2410/cpu-freq.c
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1/* linux/arch/arm/mach-s3c2410/cpu-freq.c
2 *
3 * Copyright (c) 2006,2008 Simtec Electronics
4 * http://armlinux.simtec.co.uk/
5 * Ben Dooks <ben@simtec.co.uk>
6 *
7 * S3C2410 CPU Frequency scaling
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12*/
13
14#include <linux/init.h>
15#include <linux/module.h>
16#include <linux/interrupt.h>
17#include <linux/ioport.h>
18#include <linux/cpufreq.h>
19#include <linux/sysdev.h>
20#include <linux/clk.h>
21#include <linux/err.h>
22#include <linux/io.h>
23
24#include <asm/mach/arch.h>
25#include <asm/mach/map.h>
26
27#include <mach/regs-clock.h>
28
29#include <plat/cpu.h>
30#include <plat/clock.h>
31#include <plat/cpu-freq-core.h>
32
33/* Note, 2410A has an extra mode for 1:4:4 ratio, bit 2 of CLKDIV */
34
35static void s3c2410_cpufreq_setdivs(struct s3c_cpufreq_config *cfg)
36{
37 u32 clkdiv = 0;
38
39 if (cfg->divs.h_divisor == 2)
40 clkdiv |= S3C2410_CLKDIVN_HDIVN;
41
42 if (cfg->divs.p_divisor != cfg->divs.h_divisor)
43 clkdiv |= S3C2410_CLKDIVN_PDIVN;
44
45 __raw_writel(clkdiv, S3C2410_CLKDIVN);
46}
47
48static int s3c2410_cpufreq_calcdivs(struct s3c_cpufreq_config *cfg)
49{
50 unsigned long hclk, fclk, pclk;
51 unsigned int hdiv, pdiv;
52 unsigned long hclk_max;
53
54 fclk = cfg->freq.fclk;
55 hclk_max = cfg->max.hclk;
56
57 cfg->freq.armclk = fclk;
58
59 s3c_freq_dbg("%s: fclk is %lu, max hclk %lu\n",
60 __func__, fclk, hclk_max);
61
62 hdiv = (fclk > cfg->max.hclk) ? 2 : 1;
63 hclk = fclk / hdiv;
64
65 if (hclk > cfg->max.hclk) {
66 s3c_freq_dbg("%s: hclk too big\n", __func__);
67 return -EINVAL;
68 }
69
70 pdiv = (hclk > cfg->max.pclk) ? 2 : 1;
71 pclk = hclk / pdiv;
72
73 if (pclk > cfg->max.pclk) {
74 s3c_freq_dbg("%s: pclk too big\n", __func__);
75 return -EINVAL;
76 }
77
78 pdiv *= hdiv;
79
80 /* record the result */
81 cfg->divs.p_divisor = pdiv;
82 cfg->divs.h_divisor = hdiv;
83
84 return 0 ;
85}
86
87static struct s3c_cpufreq_info s3c2410_cpufreq_info = {
88 .max = {
89 .fclk = 200000000,
90 .hclk = 100000000,
91 .pclk = 50000000,
92 },
93
94 /* transition latency is about 5ms worst-case, so
95 * set 10ms to be sure */
96 .latency = 10000000,
97
98 .locktime_m = 150,
99 .locktime_u = 150,
100 .locktime_bits = 12,
101
102 .need_pll = 1,
103
104 .name = "s3c2410",
105 .calc_iotiming = s3c2410_iotiming_calc,
106 .set_iotiming = s3c2410_iotiming_set,
107 .get_iotiming = s3c2410_iotiming_get,
108 .resume_clocks = s3c2410_setup_clocks,
109
110 .set_fvco = s3c2410_set_fvco,
111 .set_refresh = s3c2410_cpufreq_setrefresh,
112 .set_divs = s3c2410_cpufreq_setdivs,
113 .calc_divs = s3c2410_cpufreq_calcdivs,
114};
115
116static int s3c2410_cpufreq_add(struct sys_device *sysdev)
117{
118 return s3c_cpufreq_register(&s3c2410_cpufreq_info);
119}
120
121static struct sysdev_driver s3c2410_cpufreq_driver = {
122 .add = s3c2410_cpufreq_add,
123};
124
125static int __init s3c2410_cpufreq_init(void)
126{
127 return sysdev_driver_register(&s3c2410_sysclass,
128 &s3c2410_cpufreq_driver);
129}
130
131arch_initcall(s3c2410_cpufreq_init);
132
133static int s3c2410a_cpufreq_add(struct sys_device *sysdev)
134{
135 /* alter the maximum freq settings for S3C2410A. If a board knows
136 * it only has a maximum of 200, then it should register its own
137 * limits. */
138
139 s3c2410_cpufreq_info.max.fclk = 266000000;
140 s3c2410_cpufreq_info.max.hclk = 133000000;
141 s3c2410_cpufreq_info.max.pclk = 66500000;
142 s3c2410_cpufreq_info.name = "s3c2410a";
143
144 return s3c2410_cpufreq_add(sysdev);
145}
146
147static struct sysdev_driver s3c2410a_cpufreq_driver = {
148 .add = s3c2410a_cpufreq_add,
149};
150
151static int __init s3c2410a_cpufreq_init(void)
152{
153 return sysdev_driver_register(&s3c2410a_sysclass,
154 &s3c2410a_cpufreq_driver);
155}
156
157arch_initcall(s3c2410a_cpufreq_init);