diff options
Diffstat (limited to 'arch/arm/mach-s3c2410/cpu-freq.c')
-rw-r--r-- | arch/arm/mach-s3c2410/cpu-freq.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c2410/cpu-freq.c b/arch/arm/mach-s3c2410/cpu-freq.c new file mode 100644 index 000000000000..f2cbdbab0df6 --- /dev/null +++ b/arch/arm/mach-s3c2410/cpu-freq.c | |||
@@ -0,0 +1,157 @@ | |||
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 | |||
35 | static 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 | |||
48 | static 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 | |||
87 | static 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 | |||
116 | static int s3c2410_cpufreq_add(struct sys_device *sysdev) | ||
117 | { | ||
118 | return s3c_cpufreq_register(&s3c2410_cpufreq_info); | ||
119 | } | ||
120 | |||
121 | static struct sysdev_driver s3c2410_cpufreq_driver = { | ||
122 | .add = s3c2410_cpufreq_add, | ||
123 | }; | ||
124 | |||
125 | static int __init s3c2410_cpufreq_init(void) | ||
126 | { | ||
127 | return sysdev_driver_register(&s3c2410_sysclass, | ||
128 | &s3c2410_cpufreq_driver); | ||
129 | } | ||
130 | |||
131 | arch_initcall(s3c2410_cpufreq_init); | ||
132 | |||
133 | static 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 | |||
147 | static struct sysdev_driver s3c2410a_cpufreq_driver = { | ||
148 | .add = s3c2410a_cpufreq_add, | ||
149 | }; | ||
150 | |||
151 | static int __init s3c2410a_cpufreq_init(void) | ||
152 | { | ||
153 | return sysdev_driver_register(&s3c2410a_sysclass, | ||
154 | &s3c2410a_cpufreq_driver); | ||
155 | } | ||
156 | |||
157 | arch_initcall(s3c2410a_cpufreq_init); | ||