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
|
/*
* cpufreq driver for the cell processor
*
* (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007
*
* Author: Christian Krafft <krafft@de.ibm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/cpufreq.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <asm/machdep.h>
#include <asm/prom.h>
#include <asm/cell-regs.h>
#include "ppc_cbe_cpufreq.h"
static DEFINE_MUTEX(cbe_switch_mutex);
/* the CBE supports an 8 step frequency scaling */
static struct cpufreq_frequency_table cbe_freqs[] = {
{1, 0},
{2, 0},
{3, 0},
{4, 0},
{5, 0},
{6, 0},
{8, 0},
{10, 0},
{0, CPUFREQ_TABLE_END},
};
/*
* hardware specific functions
*/
static int set_pmode(unsigned int cpu, unsigned int slow_mode)
{
int rc;
if (cbe_cpufreq_has_pmi)
rc = cbe_cpufreq_set_pmode_pmi(cpu, slow_mode);
else
rc = cbe_cpufreq_set_pmode(cpu, slow_mode);
pr_debug("register contains slow mode %d\n", cbe_cpufreq_get_pmode(cpu));
return rc;
}
/*
* cpufreq functions
*/
static int cbe_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
const u32 *max_freqp;
u32 max_freq;
int i, cur_pmode;
struct device_node *cpu;
cpu = of_get_cpu_node(policy->cpu, NULL);
if (!cpu)
return -ENODEV;
pr_debug("init cpufreq on CPU %d\n", policy->cpu);
/*
* Let's check we can actually get to the CELL regs
*/
if (!cbe_get_cpu_pmd_regs(policy->cpu) ||
!cbe_get_cpu_mic_tm_regs(policy->cpu)) {
pr_info("invalid CBE regs pointers for cpufreq\n");
return -EINVAL;
}
max_freqp = of_get_property(cpu, "clock-frequency", NULL);
of_node_put(cpu);
if (!max_freqp)
return -EINVAL;
/* we need the freq in kHz */
max_freq = *max_freqp / 1000;
pr_debug("max clock-frequency is at %u kHz\n", max_freq);
pr_debug("initializing frequency table\n");
/* initialize frequency table */
for (i=0; cbe_freqs[i].frequency!=CPUFREQ_TABLE_END; i++) {
cbe_freqs[i].frequency = max_freq / cbe_freqs[i].driver_data;
pr_debug("%d: %d\n", i, cbe_freqs[i].frequency);
}
/* if DEBUG is enabled set_pmode() measures the latency
* of a transition */
policy->cpuinfo.transition_latency = 25000;
cur_pmode = cbe_cpufreq_get_pmode(policy->cpu);
pr_debug("current pmode is at %d\n",cur_pmode);
policy->cur = cbe_freqs[cur_pmode].frequency;
#ifdef CONFIG_SMP
cpumask_copy(policy->cpus, cpu_sibling_mask(policy->cpu));
#endif
/* this ensures that policy->cpuinfo_min
* and policy->cpuinfo_max are set correctly */
return cpufreq_table_validate_and_show(policy, cbe_freqs);
}
static int cbe_cpufreq_target(struct cpufreq_policy *policy,
unsigned int cbe_pmode_new)
{
int rc;
struct cpufreq_freqs freqs;
freqs.old = policy->cur;
freqs.new = cbe_freqs[cbe_pmode_new].frequency;
mutex_lock(&cbe_switch_mutex);
cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
pr_debug("setting frequency for cpu %d to %d kHz, " \
"1/%d of max frequency\n",
policy->cpu,
cbe_freqs[cbe_pmode_new].frequency,
cbe_freqs[cbe_pmode_new].driver_data);
rc = set_pmode(policy->cpu, cbe_pmode_new);
cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
mutex_unlock(&cbe_switch_mutex);
return rc;
}
static struct cpufreq_driver cbe_cpufreq_driver = {
.verify = cpufreq_generic_frequency_table_verify,
.target_index = cbe_cpufreq_target,
.init = cbe_cpufreq_cpu_init,
.exit = cpufreq_generic_exit,
.name = "cbe-cpufreq",
.flags = CPUFREQ_CONST_LOOPS,
};
/*
* module init and destoy
*/
static int __init cbe_cpufreq_init(void)
{
if (!machine_is(cell))
return -ENODEV;
return cpufreq_register_driver(&cbe_cpufreq_driver);
}
static void __exit cbe_cpufreq_exit(void)
{
cpufreq_unregister_driver(&cbe_cpufreq_driver);
}
module_init(cbe_cpufreq_init);
module_exit(cbe_cpufreq_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");
|
