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
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
|
/*
* ARM big.LITTLE Platforms CPUFreq support
*
* Copyright (C) 2013 ARM Ltd.
* Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
*
* Copyright (C) 2013 Linaro.
* Viresh Kumar <viresh.kumar@linaro.org>
*
* 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.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/clk.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/cpumask.h>
#include <linux/export.h>
#include <linux/of_platform.h>
#include <linux/pm_opp.h>
#include <linux/slab.h>
#include <linux/topology.h>
#include <linux/types.h>
#include "arm_big_little.h"
/* Currently we support only two clusters */
#define MAX_CLUSTERS 2
static struct cpufreq_arm_bL_ops *arm_bL_ops;
static struct clk *clk[MAX_CLUSTERS];
static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS];
static atomic_t cluster_usage[MAX_CLUSTERS] = {ATOMIC_INIT(0), ATOMIC_INIT(0)};
static unsigned int bL_cpufreq_get(unsigned int cpu)
{
u32 cur_cluster = cpu_to_cluster(cpu);
return clk_get_rate(clk[cur_cluster]) / 1000;
}
/* Validate policy frequency range */
static int bL_cpufreq_verify_policy(struct cpufreq_policy *policy)
{
u32 cur_cluster = cpu_to_cluster(policy->cpu);
return cpufreq_frequency_table_verify(policy, freq_table[cur_cluster]);
}
/* Set clock frequency */
static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
unsigned int target_freq, unsigned int relation)
{
struct cpufreq_freqs freqs;
u32 cpu = policy->cpu, freq_tab_idx, cur_cluster;
int ret = 0;
cur_cluster = cpu_to_cluster(policy->cpu);
freqs.old = bL_cpufreq_get(policy->cpu);
/* Determine valid target frequency using freq_table */
cpufreq_frequency_table_target(policy, freq_table[cur_cluster],
target_freq, relation, &freq_tab_idx);
freqs.new = freq_table[cur_cluster][freq_tab_idx].frequency;
pr_debug("%s: cpu: %d, cluster: %d, oldfreq: %d, target freq: %d, new freq: %d\n",
__func__, cpu, cur_cluster, freqs.old, target_freq,
freqs.new);
if (freqs.old == freqs.new)
return 0;
cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
ret = clk_set_rate(clk[cur_cluster], freqs.new * 1000);
if (ret) {
pr_err("clk_set_rate failed: %d\n", ret);
freqs.new = freqs.old;
}
cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
return ret;
}
static void put_cluster_clk_and_freq_table(struct device *cpu_dev)
{
u32 cluster = cpu_to_cluster(cpu_dev->id);
if (!atomic_dec_return(&cluster_usage[cluster])) {
clk_put(clk[cluster]);
dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
}
}
static int get_cluster_clk_and_freq_table(struct device *cpu_dev)
{
u32 cluster = cpu_to_cluster(cpu_dev->id);
char name[14] = "cpu-cluster.";
int ret;
if (atomic_inc_return(&cluster_usage[cluster]) != 1)
return 0;
ret = arm_bL_ops->init_opp_table(cpu_dev);
if (ret) {
dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n",
__func__, cpu_dev->id, ret);
goto atomic_dec;
}
ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
if (ret) {
dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n",
__func__, cpu_dev->id, ret);
goto atomic_dec;
}
name[12] = cluster + '0';
clk[cluster] = clk_get_sys(name, NULL);
if (!IS_ERR(clk[cluster])) {
dev_dbg(cpu_dev, "%s: clk: %p & freq table: %p, cluster: %d\n",
__func__, clk[cluster], freq_table[cluster],
cluster);
return 0;
}
dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n",
__func__, cpu_dev->id, cluster);
ret = PTR_ERR(clk[cluster]);
dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
atomic_dec:
atomic_dec(&cluster_usage[cluster]);
dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
cluster);
return ret;
}
/* Per-CPU initialization */
static int bL_cpufreq_init(struct cpufreq_policy *policy)
{
u32 cur_cluster = cpu_to_cluster(policy->cpu);
struct device *cpu_dev;
int ret;
cpu_dev = get_cpu_device(policy->cpu);
if (!cpu_dev) {
pr_err("%s: failed to get cpu%d device\n", __func__,
policy->cpu);
return -ENODEV;
}
ret = get_cluster_clk_and_freq_table(cpu_dev);
if (ret)
return ret;
ret = cpufreq_frequency_table_cpuinfo(policy, freq_table[cur_cluster]);
if (ret) {
dev_err(cpu_dev, "CPU %d, cluster: %d invalid freq table\n",
policy->cpu, cur_cluster);
put_cluster_clk_and_freq_table(cpu_dev);
return ret;
}
cpufreq_frequency_table_get_attr(freq_table[cur_cluster], policy->cpu);
if (arm_bL_ops->get_transition_latency)
policy->cpuinfo.transition_latency =
arm_bL_ops->get_transition_latency(cpu_dev);
else
policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
policy->cur = bL_cpufreq_get(policy->cpu);
cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
return 0;
}
static int bL_cpufreq_exit(struct cpufreq_policy *policy)
{
struct device *cpu_dev;
cpu_dev = get_cpu_device(policy->cpu);
if (!cpu_dev) {
pr_err("%s: failed to get cpu%d device\n", __func__,
policy->cpu);
return -ENODEV;
}
put_cluster_clk_and_freq_table(cpu_dev);
dev_dbg(cpu_dev, "%s: Exited, cpu: %d\n", __func__, policy->cpu);
return 0;
}
/* Export freq_table to sysfs */
static struct freq_attr *bL_cpufreq_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
NULL,
};
static struct cpufreq_driver bL_cpufreq_driver = {
.name = "arm-big-little",
.flags = CPUFREQ_STICKY,
.verify = bL_cpufreq_verify_policy,
.target = bL_cpufreq_set_target,
.get = bL_cpufreq_get,
.init = bL_cpufreq_init,
.exit = bL_cpufreq_exit,
.have_governor_per_policy = true,
.attr = bL_cpufreq_attr,
};
int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
{
int ret;
if (arm_bL_ops) {
pr_debug("%s: Already registered: %s, exiting\n", __func__,
arm_bL_ops->name);
return -EBUSY;
}
if (!ops || !strlen(ops->name) || !ops->init_opp_table) {
pr_err("%s: Invalid arm_bL_ops, exiting\n", __func__);
return -ENODEV;
}
arm_bL_ops = ops;
ret = cpufreq_register_driver(&bL_cpufreq_driver);
if (ret) {
pr_info("%s: Failed registering platform driver: %s, err: %d\n",
__func__, ops->name, ret);
arm_bL_ops = NULL;
} else {
pr_info("%s: Registered platform driver: %s\n", __func__,
ops->name);
}
return ret;
}
EXPORT_SYMBOL_GPL(bL_cpufreq_register);
void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops)
{
if (arm_bL_ops != ops) {
pr_err("%s: Registered with: %s, can't unregister, exiting\n",
__func__, arm_bL_ops->name);
return;
}
cpufreq_unregister_driver(&bL_cpufreq_driver);
pr_info("%s: Un-registered platform driver: %s\n", __func__,
arm_bL_ops->name);
arm_bL_ops = NULL;
}
EXPORT_SYMBOL_GPL(bL_cpufreq_unregister);
|
