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23#include <linux/cpufreq.h>
24#include <linux/of_platform.h>
25
26#include <asm/machdep.h>
27#include <asm/prom.h>
28#include <asm/cell-regs.h>
29#include "cbe_cpufreq.h"
30
31static DEFINE_MUTEX(cbe_switch_mutex);
32
33
34
35static struct cpufreq_frequency_table cbe_freqs[] = {
36 {1, 0},
37 {2, 0},
38 {3, 0},
39 {4, 0},
40 {5, 0},
41 {6, 0},
42 {8, 0},
43 {10, 0},
44 {0, CPUFREQ_TABLE_END},
45};
46
47
48
49
50
51static int set_pmode(unsigned int cpu, unsigned int slow_mode)
52{
53 int rc;
54
55 if (cbe_cpufreq_has_pmi)
56 rc = cbe_cpufreq_set_pmode_pmi(cpu, slow_mode);
57 else
58 rc = cbe_cpufreq_set_pmode(cpu, slow_mode);
59
60 pr_debug("register contains slow mode %d\n", cbe_cpufreq_get_pmode(cpu));
61
62 return rc;
63}
64
65
66
67
68
69static int cbe_cpufreq_cpu_init(struct cpufreq_policy *policy)
70{
71 const u32 *max_freqp;
72 u32 max_freq;
73 int i, cur_pmode;
74 struct device_node *cpu;
75
76 cpu = of_get_cpu_node(policy->cpu, NULL);
77
78 if (!cpu)
79 return -ENODEV;
80
81 pr_debug("init cpufreq on CPU %d\n", policy->cpu);
82
83
84
85
86 if (!cbe_get_cpu_pmd_regs(policy->cpu) ||
87 !cbe_get_cpu_mic_tm_regs(policy->cpu)) {
88 pr_info("invalid CBE regs pointers for cpufreq\n");
89 return -EINVAL;
90 }
91
92 max_freqp = of_get_property(cpu, "clock-frequency", NULL);
93
94 of_node_put(cpu);
95
96 if (!max_freqp)
97 return -EINVAL;
98
99
100 max_freq = *max_freqp / 1000;
101
102 pr_debug("max clock-frequency is at %u kHz\n", max_freq);
103 pr_debug("initializing frequency table\n");
104
105
106 for (i=0; cbe_freqs[i].frequency!=CPUFREQ_TABLE_END; i++) {
107 cbe_freqs[i].frequency = max_freq / cbe_freqs[i].index;
108 pr_debug("%d: %d\n", i, cbe_freqs[i].frequency);
109 }
110
111
112
113 policy->cpuinfo.transition_latency = 25000;
114
115 cur_pmode = cbe_cpufreq_get_pmode(policy->cpu);
116 pr_debug("current pmode is at %d\n",cur_pmode);
117
118 policy->cur = cbe_freqs[cur_pmode].frequency;
119
120#ifdef CONFIG_SMP
121 cpumask_copy(policy->cpus, cpu_sibling_mask(policy->cpu));
122#endif
123
124 cpufreq_frequency_table_get_attr(cbe_freqs, policy->cpu);
125
126
127
128 return cpufreq_frequency_table_cpuinfo(policy, cbe_freqs);
129}
130
131static int cbe_cpufreq_cpu_exit(struct cpufreq_policy *policy)
132{
133 cpufreq_frequency_table_put_attr(policy->cpu);
134 return 0;
135}
136
137static int cbe_cpufreq_verify(struct cpufreq_policy *policy)
138{
139 return cpufreq_frequency_table_verify(policy, cbe_freqs);
140}
141
142static int cbe_cpufreq_target(struct cpufreq_policy *policy,
143 unsigned int target_freq,
144 unsigned int relation)
145{
146 int rc;
147 struct cpufreq_freqs freqs;
148 unsigned int cbe_pmode_new;
149
150 cpufreq_frequency_table_target(policy,
151 cbe_freqs,
152 target_freq,
153 relation,
154 &cbe_pmode_new);
155
156 freqs.old = policy->cur;
157 freqs.new = cbe_freqs[cbe_pmode_new].frequency;
158 freqs.cpu = policy->cpu;
159
160 mutex_lock(&cbe_switch_mutex);
161 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
162
163 pr_debug("setting frequency for cpu %d to %d kHz, " \
164 "1/%d of max frequency\n",
165 policy->cpu,
166 cbe_freqs[cbe_pmode_new].frequency,
167 cbe_freqs[cbe_pmode_new].index);
168
169 rc = set_pmode(policy->cpu, cbe_pmode_new);
170
171 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
172 mutex_unlock(&cbe_switch_mutex);
173
174 return rc;
175}
176
177static struct cpufreq_driver cbe_cpufreq_driver = {
178 .verify = cbe_cpufreq_verify,
179 .target = cbe_cpufreq_target,
180 .init = cbe_cpufreq_cpu_init,
181 .exit = cbe_cpufreq_cpu_exit,
182 .name = "cbe-cpufreq",
183 .owner = THIS_MODULE,
184 .flags = CPUFREQ_CONST_LOOPS,
185};
186
187
188
189
190
191static int __init cbe_cpufreq_init(void)
192{
193 if (!machine_is(cell))
194 return -ENODEV;
195
196 return cpufreq_register_driver(&cbe_cpufreq_driver);
197}
198
199static void __exit cbe_cpufreq_exit(void)
200{
201 cpufreq_unregister_driver(&cbe_cpufreq_driver);
202}
203
204module_init(cbe_cpufreq_init);
205module_exit(cbe_cpufreq_exit);
206
207MODULE_LICENSE("GPL");
208MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");
209