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1da177e4 LT |
1 | /* |
2 | * This file was based upon code in Powertweak Linux (http://powertweak.sf.net) | |
14a6650f DJ |
3 | * (C) 2000-2003 Dave Jones, Arjan van de Ven, Janne Pänkälä, |
4 | * Dominik Brodowski. | |
1da177e4 LT |
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> | |
32ee8c3e | 12 | #include <linux/module.h> |
1da177e4 LT |
13 | #include <linux/init.h> |
14 | #include <linux/cpufreq.h> | |
15 | #include <linux/ioport.h> | |
8d2d2051 PC |
16 | #include <linux/timex.h> |
17 | #include <linux/io.h> | |
1da177e4 | 18 | |
fa8031ae | 19 | #include <asm/cpu_device_id.h> |
14a6650f DJ |
20 | #include <asm/msr.h> |
21 | ||
8d2d2051 PC |
22 | #define POWERNOW_IOPORT 0xfff0 /* it doesn't matter where, as long |
23 | as it is unused */ | |
1da177e4 | 24 | |
14a6650f | 25 | #define PFX "powernow-k6: " |
1da177e4 LT |
26 | static unsigned int busfreq; /* FSB, in 10 kHz */ |
27 | static unsigned int max_multiplier; | |
28 | ||
29 | ||
30 | /* Clock ratio multiplied by 10 - see table 27 in AMD#23446 */ | |
31 | static 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 | */ | |
50 | static int powernow_k6_get_cpu_multiplier(void) | |
51 | { | |
14a6650f DJ |
52 | u64 invalue = 0; |
53 | u32 msrval; | |
32ee8c3e | 54 | |
1da177e4 LT |
55 | msrval = POWERNOW_IOPORT + 0x1; |
56 | wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */ | |
8d2d2051 | 57 | invalue = inl(POWERNOW_IOPORT + 0x8); |
1da177e4 LT |
58 | msrval = POWERNOW_IOPORT + 0x0; |
59 | wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */ | |
60 | ||
50701588 | 61 | return clock_ratio[(invalue >> 5)&7].driver_data; |
1da177e4 LT |
62 | } |
63 | ||
64 | ||
65 | /** | |
9c0ebcf7 | 66 | * powernow_k6_target - set the PowerNow! multiplier |
1da177e4 LT |
67 | * @best_i: clock_ratio[best_i] is the target multiplier |
68 | * | |
69 | * Tries to change the PowerNow! multiplier | |
70 | */ | |
9c0ebcf7 | 71 | static int powernow_k6_target(struct cpufreq_policy *policy, |
b43a7ffb | 72 | unsigned int best_i) |
1da177e4 | 73 | { |
14a6650f DJ |
74 | unsigned long outvalue = 0, invalue = 0; |
75 | unsigned long msrval; | |
76 | struct cpufreq_freqs freqs; | |
1da177e4 | 77 | |
50701588 | 78 | if (clock_ratio[best_i].driver_data > max_multiplier) { |
14a6650f | 79 | printk(KERN_ERR PFX "invalid target frequency\n"); |
9c0ebcf7 | 80 | return -EINVAL; |
1da177e4 LT |
81 | } |
82 | ||
83 | freqs.old = busfreq * powernow_k6_get_cpu_multiplier(); | |
50701588 | 84 | freqs.new = busfreq * clock_ratio[best_i].driver_data; |
32ee8c3e | 85 | |
b43a7ffb | 86 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); |
1da177e4 LT |
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 */ | |
8d2d2051 | 94 | invalue = inl(POWERNOW_IOPORT + 0x8); |
1da177e4 LT |
95 | invalue = invalue & 0xf; |
96 | outvalue = outvalue | invalue; | |
8d2d2051 | 97 | outl(outvalue , (POWERNOW_IOPORT + 0x8)); |
1da177e4 LT |
98 | msrval = POWERNOW_IOPORT + 0x0; |
99 | wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */ | |
100 | ||
b43a7ffb | 101 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); |
1da177e4 | 102 | |
1da177e4 LT |
103 | return 0; |
104 | } | |
105 | ||
106 | ||
107 | static int powernow_k6_cpu_init(struct cpufreq_policy *policy) | |
108 | { | |
14a6650f | 109 | unsigned int i, f; |
1da177e4 LT |
110 | |
111 | if (policy->cpu != 0) | |
112 | return -ENODEV; | |
113 | ||
114 | /* get frequencies */ | |
115 | max_multiplier = powernow_k6_get_cpu_multiplier(); | |
116 | busfreq = cpu_khz / max_multiplier; | |
117 | ||
118 | /* table init */ | |
8d2d2051 | 119 | for (i = 0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) { |
50701588 | 120 | f = clock_ratio[i].driver_data; |
14a6650f | 121 | if (f > max_multiplier) |
1da177e4 LT |
122 | clock_ratio[i].frequency = CPUFREQ_ENTRY_INVALID; |
123 | else | |
14a6650f | 124 | clock_ratio[i].frequency = busfreq * f; |
1da177e4 LT |
125 | } |
126 | ||
127 | /* cpuinfo and default policy values */ | |
db2820dd | 128 | policy->cpuinfo.transition_latency = 200000; |
1da177e4 | 129 | |
b147405a | 130 | return cpufreq_table_validate_and_show(policy, clock_ratio); |
1da177e4 LT |
131 | } |
132 | ||
133 | ||
134 | static int powernow_k6_cpu_exit(struct cpufreq_policy *policy) | |
135 | { | |
136 | unsigned int i; | |
8d2d2051 PC |
137 | for (i = 0; i < 8; i++) { |
138 | if (i == max_multiplier) | |
9c0ebcf7 | 139 | powernow_k6_target(policy, i); |
1da177e4 LT |
140 | } |
141 | cpufreq_frequency_table_put_attr(policy->cpu); | |
32ee8c3e | 142 | return 0; |
1da177e4 LT |
143 | } |
144 | ||
145 | static unsigned int powernow_k6_get(unsigned int cpu) | |
146 | { | |
14a6650f DJ |
147 | unsigned int ret; |
148 | ret = (busfreq * powernow_k6_get_cpu_multiplier()); | |
149 | return ret; | |
1da177e4 LT |
150 | } |
151 | ||
221dee28 | 152 | static struct cpufreq_driver powernow_k6_driver = { |
d63bd27f | 153 | .verify = cpufreq_generic_frequency_table_verify, |
9c0ebcf7 | 154 | .target_index = powernow_k6_target, |
1da177e4 LT |
155 | .init = powernow_k6_cpu_init, |
156 | .exit = powernow_k6_cpu_exit, | |
157 | .get = powernow_k6_get, | |
158 | .name = "powernow-k6", | |
d63bd27f | 159 | .attr = cpufreq_generic_attr, |
1da177e4 LT |
160 | }; |
161 | ||
fa8031ae AK |
162 | static const struct x86_cpu_id powernow_k6_ids[] = { |
163 | { X86_VENDOR_AMD, 5, 12 }, | |
164 | { X86_VENDOR_AMD, 5, 13 }, | |
165 | {} | |
166 | }; | |
b4d2d231 | 167 | MODULE_DEVICE_TABLE(x86cpu, powernow_k6_ids); |
1da177e4 LT |
168 | |
169 | /** | |
170 | * powernow_k6_init - initializes the k6 PowerNow! CPUFreq driver | |
171 | * | |
172 | * Initializes the K6 PowerNow! support. Returns -ENODEV on unsupported | |
173 | * devices, -EINVAL or -ENOMEM on problems during initiatization, and zero | |
174 | * on success. | |
175 | */ | |
176 | static int __init powernow_k6_init(void) | |
32ee8c3e | 177 | { |
fa8031ae | 178 | if (!x86_match_cpu(powernow_k6_ids)) |
1da177e4 LT |
179 | return -ENODEV; |
180 | ||
181 | if (!request_region(POWERNOW_IOPORT, 16, "PowerNow!")) { | |
14a6650f | 182 | printk(KERN_INFO PFX "PowerNow IOPORT region already used.\n"); |
1da177e4 LT |
183 | return -EIO; |
184 | } | |
185 | ||
186 | if (cpufreq_register_driver(&powernow_k6_driver)) { | |
8d2d2051 | 187 | release_region(POWERNOW_IOPORT, 16); |
1da177e4 LT |
188 | return -EINVAL; |
189 | } | |
190 | ||
191 | return 0; | |
192 | } | |
193 | ||
194 | ||
195 | /** | |
196 | * powernow_k6_exit - unregisters AMD K6-2+/3+ PowerNow! support | |
197 | * | |
198 | * Unregisters AMD K6-2+ / K6-3+ PowerNow! support. | |
199 | */ | |
200 | static void __exit powernow_k6_exit(void) | |
201 | { | |
202 | cpufreq_unregister_driver(&powernow_k6_driver); | |
8d2d2051 | 203 | release_region(POWERNOW_IOPORT, 16); |
1da177e4 LT |
204 | } |
205 | ||
206 | ||
14a6650f DJ |
207 | MODULE_AUTHOR("Arjan van de Ven, Dave Jones <davej@redhat.com>, " |
208 | "Dominik Brodowski <linux@brodo.de>"); | |
8d2d2051 PC |
209 | MODULE_DESCRIPTION("PowerNow! driver for AMD K6-2+ / K6-3+ processors."); |
210 | MODULE_LICENSE("GPL"); | |
1da177e4 LT |
211 | |
212 | module_init(powernow_k6_init); | |
213 | module_exit(powernow_k6_exit); |