aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/cpufreq/exynos-cpufreq.c
blob: f99cfe24e7bca6489dcbf592372a38d1d019f4f1 (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
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
/*
 * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
 *		http://www.samsung.com
 *
 * EXYNOS - CPU frequency scaling support for EXYNOS series
 *
 * 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/kernel.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/regulator/consumer.h>
#include <linux/cpufreq.h>
#include <linux/platform_device.h>

#include <plat/cpu.h>

#include "exynos-cpufreq.h"

static struct exynos_dvfs_info *exynos_info;
static struct regulator *arm_regulator;
static unsigned int locking_frequency;

static int exynos_cpufreq_get_index(unsigned int freq)
{
	struct cpufreq_frequency_table *freq_table = exynos_info->freq_table;
	int index;

	for (index = 0;
		freq_table[index].frequency != CPUFREQ_TABLE_END; index++)
		if (freq_table[index].frequency == freq)
			break;

	if (freq_table[index].frequency == CPUFREQ_TABLE_END)
		return -EINVAL;

	return index;
}

static int exynos_cpufreq_scale(unsigned int target_freq)
{
	struct cpufreq_frequency_table *freq_table = exynos_info->freq_table;
	unsigned int *volt_table = exynos_info->volt_table;
	struct cpufreq_policy *policy = cpufreq_cpu_get(0);
	unsigned int arm_volt, safe_arm_volt = 0;
	unsigned int mpll_freq_khz = exynos_info->mpll_freq_khz;
	unsigned int old_freq;
	int index, old_index;
	int ret = 0;

	old_freq = policy->cur;

	/*
	 * The policy max have been changed so that we cannot get proper
	 * old_index with cpufreq_frequency_table_target(). Thus, ignore
	 * policy and get the index from the raw frequency table.
	 */
	old_index = exynos_cpufreq_get_index(old_freq);
	if (old_index < 0) {
		ret = old_index;
		goto out;
	}

	index = exynos_cpufreq_get_index(target_freq);
	if (index < 0) {
		ret = index;
		goto out;
	}

	/*
	 * ARM clock source will be changed APLL to MPLL temporary
	 * To support this level, need to control regulator for
	 * required voltage level
	 */
	if (exynos_info->need_apll_change != NULL) {
		if (exynos_info->need_apll_change(old_index, index) &&
		   (freq_table[index].frequency < mpll_freq_khz) &&
		   (freq_table[old_index].frequency < mpll_freq_khz))
			safe_arm_volt = volt_table[exynos_info->pll_safe_idx];
	}
	arm_volt = volt_table[index];

	/* When the new frequency is higher than current frequency */
	if ((target_freq > old_freq) && !safe_arm_volt) {
		/* Firstly, voltage up to increase frequency */
		ret = regulator_set_voltage(arm_regulator, arm_volt, arm_volt);
		if (ret) {
			pr_err("%s: failed to set cpu voltage to %d\n",
				__func__, arm_volt);
			return ret;
		}
	}

	if (safe_arm_volt) {
		ret = regulator_set_voltage(arm_regulator, safe_arm_volt,
				      safe_arm_volt);
		if (ret) {
			pr_err("%s: failed to set cpu voltage to %d\n",
				__func__, safe_arm_volt);
			return ret;
		}
	}

	exynos_info->set_freq(old_index, index);

	/* When the new frequency is lower than current frequency */
	if ((target_freq < old_freq) ||
	   ((target_freq > old_freq) && safe_arm_volt)) {
		/* down the voltage after frequency change */
		ret = regulator_set_voltage(arm_regulator, arm_volt,
				arm_volt);
		if (ret) {
			pr_err("%s: failed to set cpu voltage to %d\n",
				__func__, arm_volt);
			goto out;
		}
	}

out:
	cpufreq_cpu_put(policy);

	return ret;
}

static int exynos_target(struct cpufreq_policy *policy, unsigned int index)
{
	return exynos_cpufreq_scale(exynos_info->freq_table[index].frequency);
}

static int exynos_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
	policy->clk = exynos_info->cpu_clk;
	policy->suspend_freq = locking_frequency;
	return cpufreq_generic_init(policy, exynos_info->freq_table, 100000);
}

static struct cpufreq_driver exynos_driver = {
	.flags		= CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
	.verify		= cpufreq_generic_frequency_table_verify,
	.target_index	= exynos_target,
	.get		= cpufreq_generic_get,
	.init		= exynos_cpufreq_cpu_init,
	.name		= "exynos_cpufreq",
	.attr		= cpufreq_generic_attr,
#ifdef CONFIG_ARM_EXYNOS_CPU_FREQ_BOOST_SW
	.boost_supported = true,
#endif
#ifdef CONFIG_PM
	.suspend	= cpufreq_generic_suspend,
#endif
};

static int exynos_cpufreq_probe(struct platform_device *pdev)
{
	int ret = -EINVAL;

	exynos_info = kzalloc(sizeof(*exynos_info), GFP_KERNEL);
	if (!exynos_info)
		return -ENOMEM;

	if (soc_is_exynos4210())
		ret = exynos4210_cpufreq_init(exynos_info);
	else if (soc_is_exynos4212() || soc_is_exynos4412())
		ret = exynos4x12_cpufreq_init(exynos_info);
	else if (soc_is_exynos5250())
		ret = exynos5250_cpufreq_init(exynos_info);
	else
		return 0;

	if (ret)
		goto err_vdd_arm;

	if (exynos_info->set_freq == NULL) {
		pr_err("%s: No set_freq function (ERR)\n", __func__);
		goto err_vdd_arm;
	}

	arm_regulator = regulator_get(NULL, "vdd_arm");
	if (IS_ERR(arm_regulator)) {
		pr_err("%s: failed to get resource vdd_arm\n", __func__);
		goto err_vdd_arm;
	}

	/* Done here as we want to capture boot frequency */
	locking_frequency = clk_get_rate(exynos_info->cpu_clk) / 1000;

	if (!cpufreq_register_driver(&exynos_driver))
		return 0;

	pr_err("%s: failed to register cpufreq driver\n", __func__);
	regulator_put(arm_regulator);
err_vdd_arm:
	kfree(exynos_info);
	return -EINVAL;
}

static struct platform_driver exynos_cpufreq_platdrv = {
	.driver = {
		.name	= "exynos-cpufreq",
		.owner	= THIS_MODULE,
	},
	.probe = exynos_cpufreq_probe,
};
module_platform_driver(exynos_cpufreq_platdrv);