summaryrefslogtreecommitdiff
path: root/drivers/cpufreq/exynos4210-cpufreq.c
blob: 6384e5b9a347dab5fefdcb5aa2ad40c0924f5230 (plain) (blame)
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
/*
 * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
 *		http://www.samsung.com
 *
 * EXYNOS4210 - CPU frequency scaling support
 *
 * 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/module.h>
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/cpufreq.h>

#include "exynos-cpufreq.h"

static struct clk *cpu_clk;
static struct clk *moutcore;
static struct clk *mout_mpll;
static struct clk *mout_apll;

static unsigned int exynos4210_volt_table[] = {
	1250000, 1150000, 1050000, 975000, 950000,
};

static struct cpufreq_frequency_table exynos4210_freq_table[] = {
	{0, L0, 1200 * 1000},
	{0, L1, 1000 * 1000},
	{0, L2,  800 * 1000},
	{0, L3,  500 * 1000},
	{0, L4,  200 * 1000},
	{0, 0, CPUFREQ_TABLE_END},
};

static struct apll_freq apll_freq_4210[] = {
	/*
	 * values:
	 * freq
	 * clock divider for CORE, COREM0, COREM1, PERIPH, ATB, PCLK_DBG, APLL, RESERVED
	 * clock divider for COPY, HPM, RESERVED
	 * PLL M, P, S
	 */
	APLL_FREQ(1200, 0, 3, 7, 3, 4, 1, 7, 0, 5, 0, 0, 150, 3, 1),
	APLL_FREQ(1000, 0, 3, 7, 3, 4, 1, 7, 0, 4, 0, 0, 250, 6, 1),
	APLL_FREQ(800,  0, 3, 7, 3, 3, 1, 7, 0, 3, 0, 0, 200, 6, 1),
	APLL_FREQ(500,  0, 3, 7, 3, 3, 1, 7, 0, 3, 0, 0, 250, 6, 2),
	APLL_FREQ(200,  0, 1, 3, 1, 3, 1, 0, 0, 3, 0, 0, 200, 6, 3),
};

static void exynos4210_set_clkdiv(unsigned int div_index)
{
	unsigned int tmp;

	/* Change Divider - CPU0 */

	tmp = apll_freq_4210[div_index].clk_div_cpu0;

	__raw_writel(tmp, EXYNOS4_CLKDIV_CPU);

	do {
		tmp = __raw_readl(EXYNOS4_CLKDIV_STATCPU);
	} while (tmp & 0x1111111);

	/* Change Divider - CPU1 */

	tmp = apll_freq_4210[div_index].clk_div_cpu1;

	__raw_writel(tmp, EXYNOS4_CLKDIV_CPU1);

	do {
		tmp = __raw_readl(EXYNOS4_CLKDIV_STATCPU1);
	} while (tmp & 0x11);
}

static void exynos4210_set_apll(unsigned int index)
{
	unsigned int tmp, freq = apll_freq_4210[index].freq;

	/* MUX_CORE_SEL = MPLL, ARMCLK uses MPLL for lock time */
	clk_set_parent(moutcore, mout_mpll);

	do {
		tmp = (__raw_readl(EXYNOS4_CLKMUX_STATCPU)
			>> EXYNOS4_CLKSRC_CPU_MUXCORE_SHIFT);
		tmp &= 0x7;
	} while (tmp != 0x2);

	clk_set_rate(mout_apll, freq * 1000);

	/* MUX_CORE_SEL = APLL */
	clk_set_parent(moutcore, mout_apll);

	do {
		tmp = __raw_readl(EXYNOS4_CLKMUX_STATCPU);
		tmp &= EXYNOS4_CLKMUX_STATCPU_MUXCORE_MASK;
	} while (tmp != (0x1 << EXYNOS4_CLKSRC_CPU_MUXCORE_SHIFT));
}

static void exynos4210_set_frequency(unsigned int old_index,
				     unsigned int new_index)
{
	if (old_index > new_index) {
		exynos4210_set_clkdiv(new_index);
		exynos4210_set_apll(new_index);
	} else if (old_index < new_index) {
		exynos4210_set_apll(new_index);
		exynos4210_set_clkdiv(new_index);
	}
}

int exynos4210_cpufreq_init(struct exynos_dvfs_info *info)
{
	unsigned long rate;

	cpu_clk = clk_get(NULL, "armclk");
	if (IS_ERR(cpu_clk))
		return PTR_ERR(cpu_clk);

	moutcore = clk_get(NULL, "moutcore");
	if (IS_ERR(moutcore))
		goto err_moutcore;

	mout_mpll = clk_get(NULL, "mout_mpll");
	if (IS_ERR(mout_mpll))
		goto err_mout_mpll;

	rate = clk_get_rate(mout_mpll) / 1000;

	mout_apll = clk_get(NULL, "mout_apll");
	if (IS_ERR(mout_apll))
		goto err_mout_apll;

	info->mpll_freq_khz = rate;
	/* 800Mhz */
	info->pll_safe_idx = L2;
	info->cpu_clk = cpu_clk;
	info->volt_table = exynos4210_volt_table;
	info->freq_table = exynos4210_freq_table;
	info->set_freq = exynos4210_set_frequency;

	return 0;

err_mout_apll:
	clk_put(mout_mpll);
err_mout_mpll:
	clk_put(moutcore);
err_moutcore:
	clk_put(cpu_clk);

	pr_debug("%s: failed initialization\n", __func__);
	return -EINVAL;
}