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
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
|
/*
* CPU frequency scaling for DaVinci
*
* Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
*
* Based on linux/arch/arm/plat-omap/cpu-omap.c. Original Copyright follows:
*
* Copyright (C) 2005 Nokia Corporation
* Written by Tony Lindgren <tony@atomide.com>
*
* Based on cpu-sa1110.c, Copyright (C) 2001 Russell King
*
* Copyright (C) 2007-2008 Texas Instruments, Inc.
* Updated to support OMAP3
* Rajendra Nayak <rnayak@ti.com>
*
* 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/types.h>
#include <linux/cpufreq.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/platform_device.h>
#include <mach/hardware.h>
#include <mach/cpufreq.h>
#include <mach/common.h>
#include "clock.h"
struct davinci_cpufreq {
struct device *dev;
struct clk *armclk;
};
static struct davinci_cpufreq cpufreq;
static int davinci_verify_speed(struct cpufreq_policy *policy)
{
struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
struct cpufreq_frequency_table *freq_table = pdata->freq_table;
struct clk *armclk = cpufreq.armclk;
if (freq_table)
return cpufreq_frequency_table_verify(policy, freq_table);
if (policy->cpu)
return -EINVAL;
cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
policy->cpuinfo.max_freq);
policy->min = clk_round_rate(armclk, policy->min * 1000) / 1000;
policy->max = clk_round_rate(armclk, policy->max * 1000) / 1000;
cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
policy->cpuinfo.max_freq);
return 0;
}
static unsigned int davinci_getspeed(unsigned int cpu)
{
if (cpu)
return 0;
return clk_get_rate(cpufreq.armclk) / 1000;
}
static int davinci_target(struct cpufreq_policy *policy,
unsigned int target_freq, unsigned int relation)
{
int ret = 0;
unsigned int idx;
struct cpufreq_freqs freqs;
struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
struct clk *armclk = cpufreq.armclk;
/*
* Ensure desired rate is within allowed range. Some govenors
* (ondemand) will just pass target_freq=0 to get the minimum.
*/
if (target_freq < policy->cpuinfo.min_freq)
target_freq = policy->cpuinfo.min_freq;
if (target_freq > policy->cpuinfo.max_freq)
target_freq = policy->cpuinfo.max_freq;
freqs.old = davinci_getspeed(0);
freqs.new = clk_round_rate(armclk, target_freq * 1000) / 1000;
freqs.cpu = 0;
if (freqs.old == freqs.new)
return ret;
cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER,
dev_driver_string(cpufreq.dev),
"transition: %u --> %u\n", freqs.old, freqs.new);
ret = cpufreq_frequency_table_target(policy, pdata->freq_table,
freqs.new, relation, &idx);
if (ret)
return -EINVAL;
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
/* if moving to higher frequency, up the voltage beforehand */
if (pdata->set_voltage && freqs.new > freqs.old)
pdata->set_voltage(idx);
ret = clk_set_rate(armclk, idx);
/* if moving to lower freq, lower the voltage after lowering freq */
if (pdata->set_voltage && freqs.new < freqs.old)
pdata->set_voltage(idx);
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
return ret;
}
static int __init davinci_cpu_init(struct cpufreq_policy *policy)
{
int result = 0;
struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
struct cpufreq_frequency_table *freq_table = pdata->freq_table;
if (policy->cpu != 0)
return -EINVAL;
/* Finish platform specific initialization */
if (pdata->init) {
result = pdata->init();
if (result)
return result;
}
policy->cur = policy->min = policy->max = davinci_getspeed(0);
if (freq_table) {
result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
if (!result)
cpufreq_frequency_table_get_attr(freq_table,
policy->cpu);
} else {
policy->cpuinfo.min_freq = policy->min;
policy->cpuinfo.max_freq = policy->max;
}
policy->min = policy->cpuinfo.min_freq;
policy->max = policy->cpuinfo.max_freq;
policy->cur = davinci_getspeed(0);
/*
* Time measurement across the target() function yields ~1500-1800us
* time taken with no drivers on notification list.
* Setting the latency to 2000 us to accomodate addition of drivers
* to pre/post change notification list.
*/
policy->cpuinfo.transition_latency = 2000 * 1000;
return 0;
}
static int davinci_cpu_exit(struct cpufreq_policy *policy)
{
cpufreq_frequency_table_put_attr(policy->cpu);
return 0;
}
static struct freq_attr *davinci_cpufreq_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
NULL,
};
static struct cpufreq_driver davinci_driver = {
.flags = CPUFREQ_STICKY,
.verify = davinci_verify_speed,
.target = davinci_target,
.get = davinci_getspeed,
.init = davinci_cpu_init,
.exit = davinci_cpu_exit,
.name = "davinci",
.attr = davinci_cpufreq_attr,
};
static int __init davinci_cpufreq_probe(struct platform_device *pdev)
{
struct davinci_cpufreq_config *pdata = pdev->dev.platform_data;
if (!pdata)
return -EINVAL;
if (!pdata->freq_table)
return -EINVAL;
cpufreq.dev = &pdev->dev;
cpufreq.armclk = clk_get(NULL, "arm");
if (IS_ERR(cpufreq.armclk)) {
dev_err(cpufreq.dev, "Unable to get ARM clock\n");
return PTR_ERR(cpufreq.armclk);
}
return cpufreq_register_driver(&davinci_driver);
}
static int __exit davinci_cpufreq_remove(struct platform_device *pdev)
{
clk_put(cpufreq.armclk);
return cpufreq_unregister_driver(&davinci_driver);
}
static struct platform_driver davinci_cpufreq_driver = {
.driver = {
.name = "cpufreq-davinci",
.owner = THIS_MODULE,
},
.remove = __exit_p(davinci_cpufreq_remove),
};
static int __init davinci_cpufreq_init(void)
{
return platform_driver_probe(&davinci_cpufreq_driver,
davinci_cpufreq_probe);
}
late_initcall(davinci_cpufreq_init);
|
