Merge back earlier 'pm-cpufreq' material.
[GitHub/LineageOS/android_kernel_motorola_exynos9610.git] / drivers / cpufreq / powernow-k6.c
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1/*
2 * This file was based upon code in Powertweak Linux (http://powertweak.sf.net)
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3 * (C) 2000-2003 Dave Jones, Arjan van de Ven, Janne Pänkälä,
4 * Dominik Brodowski.
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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>
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13#include <linux/init.h>
14#include <linux/cpufreq.h>
15#include <linux/ioport.h>
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16#include <linux/timex.h>
17#include <linux/io.h>
1da177e4 18
fa8031ae 19#include <asm/cpu_device_id.h>
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20#include <asm/msr.h>
21
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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: "
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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{
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52 u64 invalue = 0;
53 u32 msrval;
32ee8c3e 54
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55 msrval = POWERNOW_IOPORT + 0x1;
56 wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
8d2d2051 57 invalue = inl(POWERNOW_IOPORT + 0x8);
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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;
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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 */
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71static void powernow_k6_set_state(struct cpufreq_policy *policy,
72 unsigned int best_i)
1da177e4 73{
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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");
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80 return;
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);
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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);
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95 invalue = invalue & 0xf;
96 outvalue = outvalue | invalue;
8d2d2051 97 outl(outvalue , (POWERNOW_IOPORT + 0x8));
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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);
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102
103 return;
104}
105
106
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107/**
108 * powernow_k6_setpolicy - sets a new CPUFreq policy
109 * @policy: new policy
110 * @target_freq: the target frequency
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111 * @relation: how that frequency relates to achieved frequency
112 * (CPUFREQ_RELATION_L or CPUFREQ_RELATION_H)
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113 *
114 * sets a new CPUFreq policy
115 */
8d2d2051 116static int powernow_k6_target(struct cpufreq_policy *policy,
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117 unsigned int target_freq,
118 unsigned int relation)
119{
14a6650f 120 unsigned int newstate = 0;
1da177e4 121
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122 if (cpufreq_frequency_table_target(policy, &clock_ratio[0],
123 target_freq, relation, &newstate))
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124 return -EINVAL;
125
b43a7ffb 126 powernow_k6_set_state(policy, newstate);
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127
128 return 0;
129}
130
131
132static int powernow_k6_cpu_init(struct cpufreq_policy *policy)
133{
14a6650f 134 unsigned int i, f;
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135
136 if (policy->cpu != 0)
137 return -ENODEV;
138
139 /* get frequencies */
140 max_multiplier = powernow_k6_get_cpu_multiplier();
141 busfreq = cpu_khz / max_multiplier;
142
143 /* table init */
8d2d2051 144 for (i = 0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) {
50701588 145 f = clock_ratio[i].driver_data;
14a6650f 146 if (f > max_multiplier)
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147 clock_ratio[i].frequency = CPUFREQ_ENTRY_INVALID;
148 else
14a6650f 149 clock_ratio[i].frequency = busfreq * f;
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150 }
151
152 /* cpuinfo and default policy values */
db2820dd 153 policy->cpuinfo.transition_latency = 200000;
1da177e4 154
b147405a 155 return cpufreq_table_validate_and_show(policy, clock_ratio);
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156}
157
158
159static int powernow_k6_cpu_exit(struct cpufreq_policy *policy)
160{
161 unsigned int i;
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162 for (i = 0; i < 8; i++) {
163 if (i == max_multiplier)
b43a7ffb 164 powernow_k6_set_state(policy, i);
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165 }
166 cpufreq_frequency_table_put_attr(policy->cpu);
32ee8c3e 167 return 0;
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168}
169
170static unsigned int powernow_k6_get(unsigned int cpu)
171{
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172 unsigned int ret;
173 ret = (busfreq * powernow_k6_get_cpu_multiplier());
174 return ret;
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175}
176
221dee28 177static struct cpufreq_driver powernow_k6_driver = {
d63bd27f 178 .verify = cpufreq_generic_frequency_table_verify,
32ee8c3e 179 .target = powernow_k6_target,
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180 .init = powernow_k6_cpu_init,
181 .exit = powernow_k6_cpu_exit,
182 .get = powernow_k6_get,
183 .name = "powernow-k6",
d63bd27f 184 .attr = cpufreq_generic_attr,
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185};
186
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187static const struct x86_cpu_id powernow_k6_ids[] = {
188 { X86_VENDOR_AMD, 5, 12 },
189 { X86_VENDOR_AMD, 5, 13 },
190 {}
191};
b4d2d231 192MODULE_DEVICE_TABLE(x86cpu, powernow_k6_ids);
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193
194/**
195 * powernow_k6_init - initializes the k6 PowerNow! CPUFreq driver
196 *
197 * Initializes the K6 PowerNow! support. Returns -ENODEV on unsupported
198 * devices, -EINVAL or -ENOMEM on problems during initiatization, and zero
199 * on success.
200 */
201static int __init powernow_k6_init(void)
32ee8c3e 202{
fa8031ae 203 if (!x86_match_cpu(powernow_k6_ids))
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204 return -ENODEV;
205
206 if (!request_region(POWERNOW_IOPORT, 16, "PowerNow!")) {
14a6650f 207 printk(KERN_INFO PFX "PowerNow IOPORT region already used.\n");
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208 return -EIO;
209 }
210
211 if (cpufreq_register_driver(&powernow_k6_driver)) {
8d2d2051 212 release_region(POWERNOW_IOPORT, 16);
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213 return -EINVAL;
214 }
215
216 return 0;
217}
218
219
220/**
221 * powernow_k6_exit - unregisters AMD K6-2+/3+ PowerNow! support
222 *
223 * Unregisters AMD K6-2+ / K6-3+ PowerNow! support.
224 */
225static void __exit powernow_k6_exit(void)
226{
227 cpufreq_unregister_driver(&powernow_k6_driver);
8d2d2051 228 release_region(POWERNOW_IOPORT, 16);
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229}
230
231
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232MODULE_AUTHOR("Arjan van de Ven, Dave Jones <davej@redhat.com>, "
233 "Dominik Brodowski <linux@brodo.de>");
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234MODULE_DESCRIPTION("PowerNow! driver for AMD K6-2+ / K6-3+ processors.");
235MODULE_LICENSE("GPL");
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236
237module_init(powernow_k6_init);
238module_exit(powernow_k6_exit);