summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-s3c2410/cpu-freq.c
blob: 5404535da1a5863f8e2a471a1a1c968f2996943d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
/* linux/arch/arm/mach-s3c2410/cpu-freq.c
 *
 * Copyright (c) 2006-2008 Simtec Electronics
 *	http://armlinux.simtec.co.uk/
 *	Ben Dooks <ben@simtec.co.uk>
 *
 * S3C2410 CPU Frequency scaling
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
*/

#include <linux/init.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/cpufreq.h>
#include <linux/device.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>

#include <asm/mach/arch.h>
#include <asm/mach/map.h>

#include <mach/regs-clock.h>

#include <plat/cpu.h>
#include <plat/clock.h>
#include <plat/cpu-freq-core.h>

/* Note, 2410A has an extra mode for 1:4:4 ratio, bit 2 of CLKDIV */

static void s3c2410_cpufreq_setdivs(struct s3c_cpufreq_config *cfg)
{
	u32 clkdiv = 0;

	if (cfg->divs.h_divisor == 2)
		clkdiv |= S3C2410_CLKDIVN_HDIVN;

	if (cfg->divs.p_divisor != cfg->divs.h_divisor)
		clkdiv |= S3C2410_CLKDIVN_PDIVN;

	__raw_writel(clkdiv, S3C2410_CLKDIVN);
}

static int s3c2410_cpufreq_calcdivs(struct s3c_cpufreq_config *cfg)
{
	unsigned long hclk, fclk, pclk;
	unsigned int hdiv, pdiv;
	unsigned long hclk_max;

	fclk = cfg->freq.fclk;
	hclk_max = cfg->max.hclk;

	cfg->freq.armclk = fclk;

	s3c_freq_dbg("%s: fclk is %lu, max hclk %lu\n",
		      __func__, fclk, hclk_max);

	hdiv = (fclk > cfg->max.hclk) ? 2 : 1;
	hclk = fclk / hdiv;

	if (hclk > cfg->max.hclk) {
		s3c_freq_dbg("%s: hclk too big\n", __func__);
		return -EINVAL;
	}

	pdiv = (hclk > cfg->max.pclk) ? 2 : 1;
	pclk = hclk / pdiv;

	if (pclk > cfg->max.pclk) {
		s3c_freq_dbg("%s: pclk too big\n", __func__);
		return -EINVAL;
	}

	pdiv *= hdiv;

	/* record the result */
	cfg->divs.p_divisor = pdiv;
	cfg->divs.h_divisor = hdiv;

	return 0      ;
}

static struct s3c_cpufreq_info s3c2410_cpufreq_info = {
	.max		= {
		.fclk	= 200000000,
		.hclk	= 100000000,
		.pclk	=  50000000,
	},

	/* transition latency is about 5ms worst-case, so
	 * set 10ms to be sure */
	.latency	= 10000000,

	.locktime_m	= 150,
	.locktime_u	= 150,
	.locktime_bits	= 12,

	.need_pll	= 1,

	.name		= "s3c2410",
	.calc_iotiming	= s3c2410_iotiming_calc,
	.set_iotiming	= s3c2410_iotiming_set,
	.get_iotiming	= s3c2410_iotiming_get,
	.resume_clocks	= s3c2410_setup_clocks,

	.set_fvco	= s3c2410_set_fvco,
	.set_refresh	= s3c2410_cpufreq_setrefresh,
	.set_divs	= s3c2410_cpufreq_setdivs,
	.calc_divs	= s3c2410_cpufreq_calcdivs,

	.debug_io_show	= s3c_cpufreq_debugfs_call(s3c2410_iotiming_debugfs),
};

static int s3c2410_cpufreq_add(struct device *dev,
			       struct subsys_interface *sif)
{
	return s3c_cpufreq_register(&s3c2410_cpufreq_info);
}

static struct subsys_interface s3c2410_cpufreq_interface = {
	.name		= "s3c2410_cpufreq",
	.subsys		= &s3c2410_subsys,
	.add_dev	= s3c2410_cpufreq_add,
};

static int __init s3c2410_cpufreq_init(void)
{
	return subsys_interface_register(&s3c2410_cpufreq_interface);
}

arch_initcall(s3c2410_cpufreq_init);

static int s3c2410a_cpufreq_add(struct device *dev,
				struct subsys_interface *sif)
{
	/* alter the maximum freq settings for S3C2410A. If a board knows
	 * it only has a maximum of 200, then it should register its own
	 * limits. */

	s3c2410_cpufreq_info.max.fclk = 266000000;
	s3c2410_cpufreq_info.max.hclk = 133000000;
	s3c2410_cpufreq_info.max.pclk =  66500000;
	s3c2410_cpufreq_info.name = "s3c2410a";

	return s3c2410_cpufreq_add(dev, sif);
}

static struct subsys_interface s3c2410a_cpufreq_interface = {
	.name		= "s3c2410a_cpufreq",
	.subsys		= &s3c2410a_subsys,
	.add_dev	= s3c2410a_cpufreq_add,
};

static int __init s3c2410a_cpufreq_init(void)
{
	return subsys_interface_register(&s3c2410a_cpufreq_interface);
}

arch_initcall(s3c2410a_cpufreq_init);
OpenPOWER on IntegriCloud