2 * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
3 * http://www.samsung.com
5 * EXYNOS - CPU frequency scaling support for EXYNOS series
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/kernel.h>
13 #include <linux/err.h>
14 #include <linux/clk.h>
16 #include <linux/slab.h>
17 #include <linux/regulator/consumer.h>
18 #include <linux/cpufreq.h>
19 #include <linux/platform_device.h>
22 #include "exynos-cpufreq.h"
24 static struct exynos_dvfs_info
*exynos_info
;
25 static struct regulator
*arm_regulator
;
26 static unsigned int locking_frequency
;
28 static int exynos_cpufreq_get_index(unsigned int freq
)
30 struct cpufreq_frequency_table
*freq_table
= exynos_info
->freq_table
;
31 struct cpufreq_frequency_table
*pos
;
33 cpufreq_for_each_entry(pos
, freq_table
)
34 if (pos
->frequency
== freq
)
37 if (pos
->frequency
== CPUFREQ_TABLE_END
)
40 return pos
- freq_table
;
43 static int exynos_cpufreq_scale(unsigned int target_freq
)
45 struct cpufreq_frequency_table
*freq_table
= exynos_info
->freq_table
;
46 unsigned int *volt_table
= exynos_info
->volt_table
;
47 struct cpufreq_policy
*policy
= cpufreq_cpu_get(0);
48 unsigned int arm_volt
, safe_arm_volt
= 0;
49 unsigned int mpll_freq_khz
= exynos_info
->mpll_freq_khz
;
50 struct device
*dev
= exynos_info
->dev
;
51 unsigned int old_freq
;
55 old_freq
= policy
->cur
;
58 * The policy max have been changed so that we cannot get proper
59 * old_index with cpufreq_frequency_table_target(). Thus, ignore
60 * policy and get the index from the raw frequency table.
62 old_index
= exynos_cpufreq_get_index(old_freq
);
68 index
= exynos_cpufreq_get_index(target_freq
);
75 * ARM clock source will be changed APLL to MPLL temporary
76 * To support this level, need to control regulator for
77 * required voltage level
79 if (exynos_info
->need_apll_change
!= NULL
) {
80 if (exynos_info
->need_apll_change(old_index
, index
) &&
81 (freq_table
[index
].frequency
< mpll_freq_khz
) &&
82 (freq_table
[old_index
].frequency
< mpll_freq_khz
))
83 safe_arm_volt
= volt_table
[exynos_info
->pll_safe_idx
];
85 arm_volt
= volt_table
[index
];
87 /* When the new frequency is higher than current frequency */
88 if ((target_freq
> old_freq
) && !safe_arm_volt
) {
89 /* Firstly, voltage up to increase frequency */
90 ret
= regulator_set_voltage(arm_regulator
, arm_volt
, arm_volt
);
92 dev_err(dev
, "failed to set cpu voltage to %d\n",
99 ret
= regulator_set_voltage(arm_regulator
, safe_arm_volt
,
102 dev_err(dev
, "failed to set cpu voltage to %d\n",
108 exynos_info
->set_freq(old_index
, index
);
110 /* When the new frequency is lower than current frequency */
111 if ((target_freq
< old_freq
) ||
112 ((target_freq
> old_freq
) && safe_arm_volt
)) {
113 /* down the voltage after frequency change */
114 ret
= regulator_set_voltage(arm_regulator
, arm_volt
,
117 dev_err(dev
, "failed to set cpu voltage to %d\n",
124 cpufreq_cpu_put(policy
);
129 static int exynos_target(struct cpufreq_policy
*policy
, unsigned int index
)
131 return exynos_cpufreq_scale(exynos_info
->freq_table
[index
].frequency
);
134 static int exynos_cpufreq_cpu_init(struct cpufreq_policy
*policy
)
136 policy
->clk
= exynos_info
->cpu_clk
;
137 policy
->suspend_freq
= locking_frequency
;
138 return cpufreq_generic_init(policy
, exynos_info
->freq_table
, 100000);
141 static struct cpufreq_driver exynos_driver
= {
142 .flags
= CPUFREQ_STICKY
| CPUFREQ_NEED_INITIAL_FREQ_CHECK
,
143 .verify
= cpufreq_generic_frequency_table_verify
,
144 .target_index
= exynos_target
,
145 .get
= cpufreq_generic_get
,
146 .init
= exynos_cpufreq_cpu_init
,
147 .name
= "exynos_cpufreq",
148 .attr
= cpufreq_generic_attr
,
149 #ifdef CONFIG_ARM_EXYNOS_CPU_FREQ_BOOST_SW
150 .boost_supported
= true,
153 .suspend
= cpufreq_generic_suspend
,
157 static int exynos_cpufreq_probe(struct platform_device
*pdev
)
161 exynos_info
= kzalloc(sizeof(*exynos_info
), GFP_KERNEL
);
165 exynos_info
->dev
= &pdev
->dev
;
167 if (of_machine_is_compatible("samsung,exynos4210")) {
168 exynos_info
->type
= EXYNOS_SOC_4210
;
169 ret
= exynos4210_cpufreq_init(exynos_info
);
170 } else if (of_machine_is_compatible("samsung,exynos4212")) {
171 exynos_info
->type
= EXYNOS_SOC_4212
;
172 ret
= exynos4x12_cpufreq_init(exynos_info
);
173 } else if (of_machine_is_compatible("samsung,exynos4412")) {
174 exynos_info
->type
= EXYNOS_SOC_4412
;
175 ret
= exynos4x12_cpufreq_init(exynos_info
);
176 } else if (of_machine_is_compatible("samsung,exynos5250")) {
177 exynos_info
->type
= EXYNOS_SOC_5250
;
178 ret
= exynos5250_cpufreq_init(exynos_info
);
180 pr_err("%s: Unknown SoC type\n", __func__
);
187 if (exynos_info
->set_freq
== NULL
) {
188 dev_err(&pdev
->dev
, "No set_freq function (ERR)\n");
192 arm_regulator
= regulator_get(NULL
, "vdd_arm");
193 if (IS_ERR(arm_regulator
)) {
194 dev_err(&pdev
->dev
, "failed to get resource vdd_arm\n");
198 /* Done here as we want to capture boot frequency */
199 locking_frequency
= clk_get_rate(exynos_info
->cpu_clk
) / 1000;
201 if (!cpufreq_register_driver(&exynos_driver
))
204 dev_err(&pdev
->dev
, "failed to register cpufreq driver\n");
205 regulator_put(arm_regulator
);
211 static struct platform_driver exynos_cpufreq_platdrv
= {
213 .name
= "exynos-cpufreq",
214 .owner
= THIS_MODULE
,
216 .probe
= exynos_cpufreq_probe
,
218 module_platform_driver(exynos_cpufreq_platdrv
);