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1/*
2 * This file was based upon code in Powertweak Linux (http://powertweak.sf.net)
3 * (C) 2000-2003 Dave Jones, Arjan van de Ven, Janne Pänkälä,
4 * Dominik Brodowski.
5 *
6 * Licensed under the terms of the GNU GPL License version 2.
7 *
8 * BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*
9 */
10
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 /* it doesn't matter where, as long
22 as it is unused */
23
24#define PFX "powernow-k6: "
25static unsigned int busfreq; /* FSB, in 10 kHz */
26static unsigned int max_multiplier;
27
28
29/* Clock ratio multiplied by 10 - see table 27 in AMD#23446 */
30static struct cpufreq_frequency_table clock_ratio[] = {
31 {45, /* 000 -> 4.5x */ 0},
32 {50, /* 001 -> 5.0x */ 0},
33 {40, /* 010 -> 4.0x */ 0},
34 {55, /* 011 -> 5.5x */ 0},
35 {20, /* 100 -> 2.0x */ 0},
36 {30, /* 101 -> 3.0x */ 0},
37 {60, /* 110 -> 6.0x */ 0},
38 {35, /* 111 -> 3.5x */ 0},
39 {0, CPUFREQ_TABLE_END}
40};
41
42
43/**
44 * powernow_k6_get_cpu_multiplier - returns the current FSB multiplier
45 *
46 * Returns the current setting of the frequency multiplier. Core clock
47 * speed is frequency of the Front-Side Bus multiplied with this value.
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); /* enable the PowerNow port */
56 invalue = inl(POWERNOW_IOPORT + 0x8);
57 msrval = POWERNOW_IOPORT + 0x0;
58 wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */
59
60 return clock_ratio[(invalue >> 5)&7].index;
61}
62
63
64/**
65 * powernow_k6_set_state - set the PowerNow! multiplier
66 * @best_i: clock_ratio[best_i] is the target multiplier
67 *
68 * Tries to change the PowerNow! multiplier
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; /* powernow-k6.c is UP only driver */
84
85 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
86
87 /* we now need to transform best_i to the BVC format, see AMD#23446 */
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); /* enable the PowerNow port */
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); /* disable it again */
99
100 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
101
102 return;
103}
104
105
106/**
107 * powernow_k6_verify - verifies a new CPUfreq policy
108 * @policy: new policy
109 *
110 * Policy must be within lowest and highest possible CPU Frequency,
111 * and at least one possible state must be within min and max.
112 */
113static int powernow_k6_verify(struct cpufreq_policy *policy)
114{
115 return cpufreq_frequency_table_verify(policy, &clock_ratio[0]);
116}
117
118
119/**
120 * powernow_k6_setpolicy - sets a new CPUFreq policy
121 * @policy: new policy
122 * @target_freq: the target frequency
123 * @relation: how that frequency relates to achieved frequency
124 * (CPUFREQ_RELATION_L or CPUFREQ_RELATION_H)
125 *
126 * sets a new CPUFreq policy
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 /* get frequencies */
153 max_multiplier = powernow_k6_get_cpu_multiplier();
154 busfreq = cpu_khz / max_multiplier;
155
156 /* table init */
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 /* cpuinfo and default policy values */
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};
212
213
214/**
215 * powernow_k6_init - initializes the k6 PowerNow! CPUFreq driver
216 *
217 * Initializes the K6 PowerNow! support. Returns -ENODEV on unsupported
218 * devices, -EINVAL or -ENOMEM on problems during initiatization, and zero
219 * on success.
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}
241
242
243/**
244 * powernow_k6_exit - unregisters AMD K6-2+/3+ PowerNow! support
245 *
246 * Unregisters AMD K6-2+ / K6-3+ PowerNow! support.
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);
1/*
2 * This file was based upon code in Powertweak Linux (http://powertweak.sf.net)
3 * (C) 2000-2003 Dave Jones, Arjan van de Ven, Janne Pänkälä,
4 * Dominik Brodowski.
5 *
6 * Licensed under the terms of the GNU GPL License version 2.
7 *
8 * BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*
9 */
10
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/cpu_device_id.h>
20#include <asm/msr.h>
21
22#define POWERNOW_IOPORT 0xfff0 /* it doesn't matter where, as long
23 as it is unused */
24
25#define PFX "powernow-k6: "
26static unsigned int busfreq; /* FSB, in 10 kHz */
27static unsigned int max_multiplier;
28
29
30/* Clock ratio multiplied by 10 - see table 27 in AMD#23446 */
31static struct cpufreq_frequency_table clock_ratio[] = {
32 {45, /* 000 -> 4.5x */ 0},
33 {50, /* 001 -> 5.0x */ 0},
34 {40, /* 010 -> 4.0x */ 0},
35 {55, /* 011 -> 5.5x */ 0},
36 {20, /* 100 -> 2.0x */ 0},
37 {30, /* 101 -> 3.0x */ 0},
38 {60, /* 110 -> 6.0x */ 0},
39 {35, /* 111 -> 3.5x */ 0},
40 {0, CPUFREQ_TABLE_END}
41};
42
43
44/**
45 * powernow_k6_get_cpu_multiplier - returns the current FSB multiplier
46 *
47 * Returns the current setting of the frequency multiplier. Core clock
48 * speed is frequency of the Front-Side Bus multiplied with this value.
49 */
50static int powernow_k6_get_cpu_multiplier(void)
51{
52 u64 invalue = 0;
53 u32 msrval;
54
55 msrval = POWERNOW_IOPORT + 0x1;
56 wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
57 invalue = inl(POWERNOW_IOPORT + 0x8);
58 msrval = POWERNOW_IOPORT + 0x0;
59 wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */
60
61 return clock_ratio[(invalue >> 5)&7].index;
62}
63
64
65/**
66 * powernow_k6_set_state - set the PowerNow! multiplier
67 * @best_i: clock_ratio[best_i] is the target multiplier
68 *
69 * Tries to change the PowerNow! multiplier
70 */
71static void powernow_k6_set_state(unsigned int best_i)
72{
73 unsigned long outvalue = 0, invalue = 0;
74 unsigned long msrval;
75 struct cpufreq_freqs freqs;
76
77 if (clock_ratio[best_i].index > max_multiplier) {
78 printk(KERN_ERR PFX "invalid target frequency\n");
79 return;
80 }
81
82 freqs.old = busfreq * powernow_k6_get_cpu_multiplier();
83 freqs.new = busfreq * clock_ratio[best_i].index;
84 freqs.cpu = 0; /* powernow-k6.c is UP only driver */
85
86 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
87
88 /* we now need to transform best_i to the BVC format, see AMD#23446 */
89
90 outvalue = (1<<12) | (1<<10) | (1<<9) | (best_i<<5);
91
92 msrval = POWERNOW_IOPORT + 0x1;
93 wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
94 invalue = inl(POWERNOW_IOPORT + 0x8);
95 invalue = invalue & 0xf;
96 outvalue = outvalue | invalue;
97 outl(outvalue , (POWERNOW_IOPORT + 0x8));
98 msrval = POWERNOW_IOPORT + 0x0;
99 wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */
100
101 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
102
103 return;
104}
105
106
107/**
108 * powernow_k6_verify - verifies a new CPUfreq policy
109 * @policy: new policy
110 *
111 * Policy must be within lowest and highest possible CPU Frequency,
112 * and at least one possible state must be within min and max.
113 */
114static int powernow_k6_verify(struct cpufreq_policy *policy)
115{
116 return cpufreq_frequency_table_verify(policy, &clock_ratio[0]);
117}
118
119
120/**
121 * powernow_k6_setpolicy - sets a new CPUFreq policy
122 * @policy: new policy
123 * @target_freq: the target frequency
124 * @relation: how that frequency relates to achieved frequency
125 * (CPUFREQ_RELATION_L or CPUFREQ_RELATION_H)
126 *
127 * sets a new CPUFreq policy
128 */
129static int powernow_k6_target(struct cpufreq_policy *policy,
130 unsigned int target_freq,
131 unsigned int relation)
132{
133 unsigned int newstate = 0;
134
135 if (cpufreq_frequency_table_target(policy, &clock_ratio[0],
136 target_freq, relation, &newstate))
137 return -EINVAL;
138
139 powernow_k6_set_state(newstate);
140
141 return 0;
142}
143
144
145static int powernow_k6_cpu_init(struct cpufreq_policy *policy)
146{
147 unsigned int i, f;
148 int result;
149
150 if (policy->cpu != 0)
151 return -ENODEV;
152
153 /* get frequencies */
154 max_multiplier = powernow_k6_get_cpu_multiplier();
155 busfreq = cpu_khz / max_multiplier;
156
157 /* table init */
158 for (i = 0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) {
159 f = clock_ratio[i].index;
160 if (f > max_multiplier)
161 clock_ratio[i].frequency = CPUFREQ_ENTRY_INVALID;
162 else
163 clock_ratio[i].frequency = busfreq * f;
164 }
165
166 /* cpuinfo and default policy values */
167 policy->cpuinfo.transition_latency = 200000;
168 policy->cur = busfreq * max_multiplier;
169
170 result = cpufreq_frequency_table_cpuinfo(policy, clock_ratio);
171 if (result)
172 return result;
173
174 cpufreq_frequency_table_get_attr(clock_ratio, policy->cpu);
175
176 return 0;
177}
178
179
180static int powernow_k6_cpu_exit(struct cpufreq_policy *policy)
181{
182 unsigned int i;
183 for (i = 0; i < 8; i++) {
184 if (i == max_multiplier)
185 powernow_k6_set_state(i);
186 }
187 cpufreq_frequency_table_put_attr(policy->cpu);
188 return 0;
189}
190
191static unsigned int powernow_k6_get(unsigned int cpu)
192{
193 unsigned int ret;
194 ret = (busfreq * powernow_k6_get_cpu_multiplier());
195 return ret;
196}
197
198static struct freq_attr *powernow_k6_attr[] = {
199 &cpufreq_freq_attr_scaling_available_freqs,
200 NULL,
201};
202
203static struct cpufreq_driver powernow_k6_driver = {
204 .verify = powernow_k6_verify,
205 .target = powernow_k6_target,
206 .init = powernow_k6_cpu_init,
207 .exit = powernow_k6_cpu_exit,
208 .get = powernow_k6_get,
209 .name = "powernow-k6",
210 .owner = THIS_MODULE,
211 .attr = powernow_k6_attr,
212};
213
214static const struct x86_cpu_id powernow_k6_ids[] = {
215 { X86_VENDOR_AMD, 5, 12 },
216 { X86_VENDOR_AMD, 5, 13 },
217 {}
218};
219MODULE_DEVICE_TABLE(x86cpu, powernow_k6_ids);
220
221/**
222 * powernow_k6_init - initializes the k6 PowerNow! CPUFreq driver
223 *
224 * Initializes the K6 PowerNow! support. Returns -ENODEV on unsupported
225 * devices, -EINVAL or -ENOMEM on problems during initiatization, and zero
226 * on success.
227 */
228static int __init powernow_k6_init(void)
229{
230 if (!x86_match_cpu(powernow_k6_ids))
231 return -ENODEV;
232
233 if (!request_region(POWERNOW_IOPORT, 16, "PowerNow!")) {
234 printk(KERN_INFO PFX "PowerNow IOPORT region already used.\n");
235 return -EIO;
236 }
237
238 if (cpufreq_register_driver(&powernow_k6_driver)) {
239 release_region(POWERNOW_IOPORT, 16);
240 return -EINVAL;
241 }
242
243 return 0;
244}
245
246
247/**
248 * powernow_k6_exit - unregisters AMD K6-2+/3+ PowerNow! support
249 *
250 * Unregisters AMD K6-2+ / K6-3+ PowerNow! support.
251 */
252static void __exit powernow_k6_exit(void)
253{
254 cpufreq_unregister_driver(&powernow_k6_driver);
255 release_region(POWERNOW_IOPORT, 16);
256}
257
258
259MODULE_AUTHOR("Arjan van de Ven, Dave Jones <davej@redhat.com>, "
260 "Dominik Brodowski <linux@brodo.de>");
261MODULE_DESCRIPTION("PowerNow! driver for AMD K6-2+ / K6-3+ processors.");
262MODULE_LICENSE("GPL");
263
264module_init(powernow_k6_init);
265module_exit(powernow_k6_exit);