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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * This file was based upon code in Powertweak Linux (http://powertweak.sf.net)
Dave Jones14a66502009-01-18 00:00:04 -05003 * (C) 2000-2003 Dave Jones, Arjan van de Ven, Janne Pänkälä,
4 * Dominik Brodowski.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 *
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>
Dave Jones32ee8c32006-02-28 00:43:23 -050012#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/init.h>
14#include <linux/cpufreq.h>
15#include <linux/ioport.h>
Paolo Ciarrocchi8d2d2052008-07-28 21:08:16 +020016#include <linux/timex.h>
17#include <linux/io.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018
Andi Kleenfa8031a2012-01-26 00:09:12 +010019#include <asm/cpu_device_id.h>
Dave Jones14a66502009-01-18 00:00:04 -050020#include <asm/msr.h>
21
Paolo Ciarrocchi8d2d2052008-07-28 21:08:16 +020022#define POWERNOW_IOPORT 0xfff0 /* it doesn't matter where, as long
23 as it is unused */
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
Dave Jones14a66502009-01-18 00:00:04 -050025#define PFX "powernow-k6: "
Linus Torvalds1da177e2005-04-16 15:20:36 -070026static 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{
Dave Jones14a66502009-01-18 00:00:04 -050052 u64 invalue = 0;
53 u32 msrval;
Dave Jones32ee8c32006-02-28 00:43:23 -050054
Linus Torvalds1da177e2005-04-16 15:20:36 -070055 msrval = POWERNOW_IOPORT + 0x1;
56 wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
Paolo Ciarrocchi8d2d2052008-07-28 21:08:16 +020057 invalue = inl(POWERNOW_IOPORT + 0x8);
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 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 */
Paolo Ciarrocchi8d2d2052008-07-28 21:08:16 +020071static void powernow_k6_set_state(unsigned int best_i)
Linus Torvalds1da177e2005-04-16 15:20:36 -070072{
Dave Jones14a66502009-01-18 00:00:04 -050073 unsigned long outvalue = 0, invalue = 0;
74 unsigned long msrval;
75 struct cpufreq_freqs freqs;
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
77 if (clock_ratio[best_i].index > max_multiplier) {
Dave Jones14a66502009-01-18 00:00:04 -050078 printk(KERN_ERR PFX "invalid target frequency\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 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 */
Dave Jones32ee8c32006-02-28 00:43:23 -050085
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 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 */
Paolo Ciarrocchi8d2d2052008-07-28 21:08:16 +020094 invalue = inl(POWERNOW_IOPORT + 0x8);
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 invalue = invalue & 0xf;
96 outvalue = outvalue | invalue;
Paolo Ciarrocchi8d2d2052008-07-28 21:08:16 +020097 outl(outvalue , (POWERNOW_IOPORT + 0x8));
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 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
Dave Jones14a66502009-01-18 00:00:04 -0500124 * @relation: how that frequency relates to achieved frequency
125 * (CPUFREQ_RELATION_L or CPUFREQ_RELATION_H)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 *
127 * sets a new CPUFreq policy
128 */
Paolo Ciarrocchi8d2d2052008-07-28 21:08:16 +0200129static int powernow_k6_target(struct cpufreq_policy *policy,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 unsigned int target_freq,
131 unsigned int relation)
132{
Dave Jones14a66502009-01-18 00:00:04 -0500133 unsigned int newstate = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134
Dave Jones14a66502009-01-18 00:00:04 -0500135 if (cpufreq_frequency_table_target(policy, &clock_ratio[0],
136 target_freq, relation, &newstate))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 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{
Dave Jones14a66502009-01-18 00:00:04 -0500147 unsigned int i, f;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 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 */
Paolo Ciarrocchi8d2d2052008-07-28 21:08:16 +0200158 for (i = 0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) {
Dave Jones14a66502009-01-18 00:00:04 -0500159 f = clock_ratio[i].index;
160 if (f > max_multiplier)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 clock_ratio[i].frequency = CPUFREQ_ENTRY_INVALID;
162 else
Dave Jones14a66502009-01-18 00:00:04 -0500163 clock_ratio[i].frequency = busfreq * f;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 }
165
166 /* cpuinfo and default policy values */
Krzysztof Heltdb2820d2009-10-25 19:45:57 +0100167 policy->cpuinfo.transition_latency = 200000;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 policy->cur = busfreq * max_multiplier;
169
170 result = cpufreq_frequency_table_cpuinfo(policy, clock_ratio);
171 if (result)
Paolo Ciarrocchi8d2d2052008-07-28 21:08:16 +0200172 return result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173
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;
Paolo Ciarrocchi8d2d2052008-07-28 21:08:16 +0200183 for (i = 0; i < 8; i++) {
184 if (i == max_multiplier)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 powernow_k6_set_state(i);
186 }
187 cpufreq_frequency_table_put_attr(policy->cpu);
Dave Jones32ee8c32006-02-28 00:43:23 -0500188 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189}
190
191static unsigned int powernow_k6_get(unsigned int cpu)
192{
Dave Jones14a66502009-01-18 00:00:04 -0500193 unsigned int ret;
194 ret = (busfreq * powernow_k6_get_cpu_multiplier());
195 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196}
197
Paolo Ciarrocchi8d2d2052008-07-28 21:08:16 +0200198static struct freq_attr *powernow_k6_attr[] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 &cpufreq_freq_attr_scaling_available_freqs,
200 NULL,
201};
202
Linus Torvalds221dee22007-02-26 14:55:48 -0800203static struct cpufreq_driver powernow_k6_driver = {
Dave Jones32ee8c32006-02-28 00:43:23 -0500204 .verify = powernow_k6_verify,
205 .target = powernow_k6_target,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 .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
Andi Kleenfa8031a2012-01-26 00:09:12 +0100214static const struct x86_cpu_id powernow_k6_ids[] = {
215 { X86_VENDOR_AMD, 5, 12 },
216 { X86_VENDOR_AMD, 5, 13 },
217 {}
218};
Ben Hutchingsb4d2d232012-02-11 23:04:12 +0000219MODULE_DEVICE_TABLE(x86cpu, powernow_k6_ids);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220
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)
Dave Jones32ee8c32006-02-28 00:43:23 -0500229{
Andi Kleenfa8031a2012-01-26 00:09:12 +0100230 if (!x86_match_cpu(powernow_k6_ids))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 return -ENODEV;
232
233 if (!request_region(POWERNOW_IOPORT, 16, "PowerNow!")) {
Dave Jones14a66502009-01-18 00:00:04 -0500234 printk(KERN_INFO PFX "PowerNow IOPORT region already used.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 return -EIO;
236 }
237
238 if (cpufreq_register_driver(&powernow_k6_driver)) {
Paolo Ciarrocchi8d2d2052008-07-28 21:08:16 +0200239 release_region(POWERNOW_IOPORT, 16);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 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);
Paolo Ciarrocchi8d2d2052008-07-28 21:08:16 +0200255 release_region(POWERNOW_IOPORT, 16);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256}
257
258
Dave Jones14a66502009-01-18 00:00:04 -0500259MODULE_AUTHOR("Arjan van de Ven, Dave Jones <davej@redhat.com>, "
260 "Dominik Brodowski <linux@brodo.de>");
Paolo Ciarrocchi8d2d2052008-07-28 21:08:16 +0200261MODULE_DESCRIPTION("PowerNow! driver for AMD K6-2+ / K6-3+ processors.");
262MODULE_LICENSE("GPL");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263
264module_init(powernow_k6_init);
265module_exit(powernow_k6_exit);