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11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/cpufreq.h>
15#include <linux/ioport.h>
16#include <linux/timex.h>
17#include <linux/io.h>
18
19#include <asm/msr.h>
20
21#define POWERNOW_IOPORT 0xfff0
22
23
24#define PFX "powernow-k6: "
25static unsigned int busfreq;
26static unsigned int max_multiplier;
27
28
29
30static struct cpufreq_frequency_table clock_ratio[] = {
31 {45, 0},
32 {50, 0},
33 {40, 0},
34 {55, 0},
35 {20, 0},
36 {30, 0},
37 {60, 0},
38 {35, 0},
39 {0, CPUFREQ_TABLE_END}
40};
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47
48
49static int powernow_k6_get_cpu_multiplier(void)
50{
51 u64 invalue = 0;
52 u32 msrval;
53
54 msrval = POWERNOW_IOPORT + 0x1;
55 wrmsr(MSR_K6_EPMR, msrval, 0);
56 invalue = inl(POWERNOW_IOPORT + 0x8);
57 msrval = POWERNOW_IOPORT + 0x0;
58 wrmsr(MSR_K6_EPMR, msrval, 0);
59
60 return clock_ratio[(invalue >> 5)&7].index;
61}
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69
70static void powernow_k6_set_state(unsigned int best_i)
71{
72 unsigned long outvalue = 0, invalue = 0;
73 unsigned long msrval;
74 struct cpufreq_freqs freqs;
75
76 if (clock_ratio[best_i].index > max_multiplier) {
77 printk(KERN_ERR PFX "invalid target frequency\n");
78 return;
79 }
80
81 freqs.old = busfreq * powernow_k6_get_cpu_multiplier();
82 freqs.new = busfreq * clock_ratio[best_i].index;
83 freqs.cpu = 0;
84
85 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
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88
89 outvalue = (1<<12) | (1<<10) | (1<<9) | (best_i<<5);
90
91 msrval = POWERNOW_IOPORT + 0x1;
92 wrmsr(MSR_K6_EPMR, msrval, 0);
93 invalue = inl(POWERNOW_IOPORT + 0x8);
94 invalue = invalue & 0xf;
95 outvalue = outvalue | invalue;
96 outl(outvalue , (POWERNOW_IOPORT + 0x8));
97 msrval = POWERNOW_IOPORT + 0x0;
98 wrmsr(MSR_K6_EPMR, msrval, 0);
99
100 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
101
102 return;
103}
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112
113static int powernow_k6_verify(struct cpufreq_policy *policy)
114{
115 return cpufreq_frequency_table_verify(policy, &clock_ratio[0]);
116}
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127
128static int powernow_k6_target(struct cpufreq_policy *policy,
129 unsigned int target_freq,
130 unsigned int relation)
131{
132 unsigned int newstate = 0;
133
134 if (cpufreq_frequency_table_target(policy, &clock_ratio[0],
135 target_freq, relation, &newstate))
136 return -EINVAL;
137
138 powernow_k6_set_state(newstate);
139
140 return 0;
141}
142
143
144static int powernow_k6_cpu_init(struct cpufreq_policy *policy)
145{
146 unsigned int i, f;
147 int result;
148
149 if (policy->cpu != 0)
150 return -ENODEV;
151
152
153 max_multiplier = powernow_k6_get_cpu_multiplier();
154 busfreq = cpu_khz / max_multiplier;
155
156
157 for (i = 0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) {
158 f = clock_ratio[i].index;
159 if (f > max_multiplier)
160 clock_ratio[i].frequency = CPUFREQ_ENTRY_INVALID;
161 else
162 clock_ratio[i].frequency = busfreq * f;
163 }
164
165
166 policy->cpuinfo.transition_latency = 200000;
167 policy->cur = busfreq * max_multiplier;
168
169 result = cpufreq_frequency_table_cpuinfo(policy, clock_ratio);
170 if (result)
171 return result;
172
173 cpufreq_frequency_table_get_attr(clock_ratio, policy->cpu);
174
175 return 0;
176}
177
178
179static int powernow_k6_cpu_exit(struct cpufreq_policy *policy)
180{
181 unsigned int i;
182 for (i = 0; i < 8; i++) {
183 if (i == max_multiplier)
184 powernow_k6_set_state(i);
185 }
186 cpufreq_frequency_table_put_attr(policy->cpu);
187 return 0;
188}
189
190static unsigned int powernow_k6_get(unsigned int cpu)
191{
192 unsigned int ret;
193 ret = (busfreq * powernow_k6_get_cpu_multiplier());
194 return ret;
195}
196
197static struct freq_attr *powernow_k6_attr[] = {
198 &cpufreq_freq_attr_scaling_available_freqs,
199 NULL,
200};
201
202static struct cpufreq_driver powernow_k6_driver = {
203 .verify = powernow_k6_verify,
204 .target = powernow_k6_target,
205 .init = powernow_k6_cpu_init,
206 .exit = powernow_k6_cpu_exit,
207 .get = powernow_k6_get,
208 .name = "powernow-k6",
209 .owner = THIS_MODULE,
210 .attr = powernow_k6_attr,
211};
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220
221static int __init powernow_k6_init(void)
222{
223 struct cpuinfo_x86 *c = &cpu_data(0);
224
225 if ((c->x86_vendor != X86_VENDOR_AMD) || (c->x86 != 5) ||
226 ((c->x86_model != 12) && (c->x86_model != 13)))
227 return -ENODEV;
228
229 if (!request_region(POWERNOW_IOPORT, 16, "PowerNow!")) {
230 printk(KERN_INFO PFX "PowerNow IOPORT region already used.\n");
231 return -EIO;
232 }
233
234 if (cpufreq_register_driver(&powernow_k6_driver)) {
235 release_region(POWERNOW_IOPORT, 16);
236 return -EINVAL;
237 }
238
239 return 0;
240}
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246
247
248static void __exit powernow_k6_exit(void)
249{
250 cpufreq_unregister_driver(&powernow_k6_driver);
251 release_region(POWERNOW_IOPORT, 16);
252}
253
254
255MODULE_AUTHOR("Arjan van de Ven, Dave Jones <davej@redhat.com>, "
256 "Dominik Brodowski <linux@brodo.de>");
257MODULE_DESCRIPTION("PowerNow! driver for AMD K6-2+ / K6-3+ processors.");
258MODULE_LICENSE("GPL");
259
260module_init(powernow_k6_init);
261module_exit(powernow_k6_exit);
262