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1da177e4 LT |
1 | /* |
2 | * This file was based upon code in Powertweak Linux (http://powertweak.sf.net) | |
96de0e25 | 3 | * (C) 2000-2003 Dave Jones, Arjan van de Ven, Janne Pänkälä, Dominik Brodowski. |
1da177e4 LT |
4 | * |
5 | * Licensed under the terms of the GNU GPL License version 2. | |
6 | * | |
7 | * BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous* | |
8 | */ | |
9 | ||
10 | #include <linux/kernel.h> | |
32ee8c3e | 11 | #include <linux/module.h> |
1da177e4 LT |
12 | #include <linux/init.h> |
13 | #include <linux/cpufreq.h> | |
14 | #include <linux/ioport.h> | |
15 | #include <linux/slab.h> | |
16 | ||
17 | #include <asm/msr.h> | |
18 | #include <asm/timex.h> | |
19 | #include <asm/io.h> | |
20 | ||
21 | ||
22 | #define POWERNOW_IOPORT 0xfff0 /* it doesn't matter where, as long | |
23 | as it is unused */ | |
24 | ||
25 | static unsigned int busfreq; /* FSB, in 10 kHz */ | |
26 | static unsigned int max_multiplier; | |
27 | ||
28 | ||
29 | /* Clock ratio multiplied by 10 - see table 27 in AMD#23446 */ | |
30 | static 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 | */ | |
49 | static int powernow_k6_get_cpu_multiplier(void) | |
50 | { | |
51 | u64 invalue = 0; | |
52 | u32 msrval; | |
32ee8c3e | 53 | |
1da177e4 LT |
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 | */ | |
70 | static 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 "cpufreq: 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 */ | |
32ee8c3e | 84 | |
1da177e4 LT |
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 | */ | |
113 | static 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 (CPUFREQ_RELATION_L or CPUFREQ_RELATION_H) | |
124 | * | |
125 | * sets a new CPUFreq policy | |
126 | */ | |
127 | static int powernow_k6_target (struct cpufreq_policy *policy, | |
128 | unsigned int target_freq, | |
129 | unsigned int relation) | |
130 | { | |
131 | unsigned int newstate = 0; | |
132 | ||
133 | if (cpufreq_frequency_table_target(policy, &clock_ratio[0], target_freq, relation, &newstate)) | |
134 | return -EINVAL; | |
135 | ||
136 | powernow_k6_set_state(newstate); | |
137 | ||
138 | return 0; | |
139 | } | |
140 | ||
141 | ||
142 | static int powernow_k6_cpu_init(struct cpufreq_policy *policy) | |
143 | { | |
144 | unsigned int i; | |
145 | int result; | |
146 | ||
147 | if (policy->cpu != 0) | |
148 | return -ENODEV; | |
149 | ||
150 | /* get frequencies */ | |
151 | max_multiplier = powernow_k6_get_cpu_multiplier(); | |
152 | busfreq = cpu_khz / max_multiplier; | |
153 | ||
154 | /* table init */ | |
32ee8c3e | 155 | for (i=0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) { |
1da177e4 LT |
156 | if (clock_ratio[i].index > max_multiplier) |
157 | clock_ratio[i].frequency = CPUFREQ_ENTRY_INVALID; | |
158 | else | |
159 | clock_ratio[i].frequency = busfreq * clock_ratio[i].index; | |
160 | } | |
161 | ||
162 | /* cpuinfo and default policy values */ | |
1da177e4 LT |
163 | policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; |
164 | policy->cur = busfreq * max_multiplier; | |
165 | ||
166 | result = cpufreq_frequency_table_cpuinfo(policy, clock_ratio); | |
167 | if (result) | |
168 | return (result); | |
169 | ||
170 | cpufreq_frequency_table_get_attr(clock_ratio, policy->cpu); | |
171 | ||
172 | return 0; | |
173 | } | |
174 | ||
175 | ||
176 | static int powernow_k6_cpu_exit(struct cpufreq_policy *policy) | |
177 | { | |
178 | unsigned int i; | |
179 | for (i=0; i<8; i++) { | |
180 | if (i==max_multiplier) | |
181 | powernow_k6_set_state(i); | |
182 | } | |
183 | cpufreq_frequency_table_put_attr(policy->cpu); | |
32ee8c3e | 184 | return 0; |
1da177e4 LT |
185 | } |
186 | ||
187 | static unsigned int powernow_k6_get(unsigned int cpu) | |
188 | { | |
189 | return busfreq * powernow_k6_get_cpu_multiplier(); | |
190 | } | |
191 | ||
192 | static struct freq_attr* powernow_k6_attr[] = { | |
193 | &cpufreq_freq_attr_scaling_available_freqs, | |
194 | NULL, | |
195 | }; | |
196 | ||
221dee28 | 197 | static struct cpufreq_driver powernow_k6_driver = { |
32ee8c3e DJ |
198 | .verify = powernow_k6_verify, |
199 | .target = powernow_k6_target, | |
1da177e4 LT |
200 | .init = powernow_k6_cpu_init, |
201 | .exit = powernow_k6_cpu_exit, | |
202 | .get = powernow_k6_get, | |
203 | .name = "powernow-k6", | |
204 | .owner = THIS_MODULE, | |
205 | .attr = powernow_k6_attr, | |
206 | }; | |
207 | ||
208 | ||
209 | /** | |
210 | * powernow_k6_init - initializes the k6 PowerNow! CPUFreq driver | |
211 | * | |
212 | * Initializes the K6 PowerNow! support. Returns -ENODEV on unsupported | |
213 | * devices, -EINVAL or -ENOMEM on problems during initiatization, and zero | |
214 | * on success. | |
215 | */ | |
216 | static int __init powernow_k6_init(void) | |
32ee8c3e | 217 | { |
1da177e4 LT |
218 | struct cpuinfo_x86 *c = cpu_data; |
219 | ||
220 | if ((c->x86_vendor != X86_VENDOR_AMD) || (c->x86 != 5) || | |
221 | ((c->x86_model != 12) && (c->x86_model != 13))) | |
222 | return -ENODEV; | |
223 | ||
224 | if (!request_region(POWERNOW_IOPORT, 16, "PowerNow!")) { | |
225 | printk("cpufreq: PowerNow IOPORT region already used.\n"); | |
226 | return -EIO; | |
227 | } | |
228 | ||
229 | if (cpufreq_register_driver(&powernow_k6_driver)) { | |
230 | release_region (POWERNOW_IOPORT, 16); | |
231 | return -EINVAL; | |
232 | } | |
233 | ||
234 | return 0; | |
235 | } | |
236 | ||
237 | ||
238 | /** | |
239 | * powernow_k6_exit - unregisters AMD K6-2+/3+ PowerNow! support | |
240 | * | |
241 | * Unregisters AMD K6-2+ / K6-3+ PowerNow! support. | |
242 | */ | |
243 | static void __exit powernow_k6_exit(void) | |
244 | { | |
245 | cpufreq_unregister_driver(&powernow_k6_driver); | |
246 | release_region (POWERNOW_IOPORT, 16); | |
247 | } | |
248 | ||
249 | ||
250 | MODULE_AUTHOR ("Arjan van de Ven <arjanv@redhat.com>, Dave Jones <davej@codemonkey.org.uk>, Dominik Brodowski <linux@brodo.de>"); | |
251 | MODULE_DESCRIPTION ("PowerNow! driver for AMD K6-2+ / K6-3+ processors."); | |
252 | MODULE_LICENSE ("GPL"); | |
253 | ||
254 | module_init(powernow_k6_init); | |
255 | module_exit(powernow_k6_exit); |