aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/cpufreq/exynos4210-cpufreq.c
blob: add7fbec4fc9af5ca3060e925cfe662a25d21eb4 (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
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
/*
 * 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 <mach/regs-clock.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[] = {
	{L0, 1200 * 1000},
	{L1, 1000 * 1000},
	{L2,  800 * 1000},
	{L3,  500 * 1000},
	{L4,  200 * 1000},
	{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;

	/* 1. 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);

	/* 2. Set APLL Lock time */
	__raw_writel(EXYNOS4_APLL_LOCKTIME, EXYNOS4_APLL_LOCK);

	/* 3. Change PLL PMS values */
	tmp = __raw_readl(EXYNOS4_APLL_CON0);
	tmp &= ~((0x3ff << 16) | (0x3f << 8) | (0x7 << 0));
	tmp |= apll_freq_4210[index].mps;
	__raw_writel(tmp, EXYNOS4_APLL_CON0);

	/* 4. wait_lock_time */
	do {
		tmp = __raw_readl(EXYNOS4_APLL_CON0);
	} while (!(tmp & (0x1 << EXYNOS4_APLLCON0_LOCKED_SHIFT)));

	/* 5. 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 bool exynos4210_pms_change(unsigned int old_index, unsigned int new_index)
{
	unsigned int old_pm = apll_freq_4210[old_index].mps >> 8;
	unsigned int new_pm = apll_freq_4210[new_index].mps >> 8;

	return (old_pm == new_pm) ? 0 : 1;
}

static void exynos4210_set_frequency(unsigned int old_index,
				     unsigned int new_index)
{
	unsigned int tmp;

	if (old_index > new_index) {
		if (!exynos4210_pms_change(old_index, new_index)) {
			/* 1. Change the system clock divider values */
			exynos4210_set_clkdiv(new_index);

			/* 2. Change just s value in apll m,p,s value */
			tmp = __raw_readl(EXYNOS4_APLL_CON0);
			tmp &= ~(0x7 << 0);
			tmp |= apll_freq_4210[new_index].mps & 0x7;
			__raw_writel(tmp, EXYNOS4_APLL_CON0);
		} else {
			/* Clock Configuration Procedure */
			/* 1. Change the system clock divider values */
			exynos4210_set_clkdiv(new_index);
			/* 2. Change the apll m,p,s value */
			exynos4210_set_apll(new_index);
		}
	} else if (old_index < new_index) {
		if (!exynos4210_pms_change(old_index, new_index)) {
			/* 1. Change just s value in apll m,p,s value */
			tmp = __raw_readl(EXYNOS4_APLL_CON0);
			tmp &= ~(0x7 << 0);
			tmp |= apll_freq_4210[new_index].mps & 0x7;
			__raw_writel(tmp, EXYNOS4_APLL_CON0);

			/* 2. Change the system clock divider values */
			exynos4210_set_clkdiv(new_index);
		} else {
			/* Clock Configuration Procedure */
			/* 1. Change the apll m,p,s value */
			exynos4210_set_apll(new_index);
			/* 2. Change the system clock divider values */
			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;
	info->need_apll_change = exynos4210_pms_change;

	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;
}
EXPORT_SYMBOL(exynos4210_cpufreq_init);