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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
Mikulas Patockad82b9222013-12-11 19:38:53 -050029static unsigned int param_busfreq = 0;
30static unsigned int param_max_multiplier = 0;
31
32module_param_named(max_multiplier, param_max_multiplier, uint, S_IRUGO);
33MODULE_PARM_DESC(max_multiplier, "Maximum multiplier (allowed values: 20 30 35 40 45 50 55 60)");
34
35module_param_named(bus_frequency, param_busfreq, uint, S_IRUGO);
36MODULE_PARM_DESC(bus_frequency, "Bus frequency in kHz");
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
38/* Clock ratio multiplied by 10 - see table 27 in AMD#23446 */
39static struct cpufreq_frequency_table clock_ratio[] = {
Viresh Kumar7f4b0462014-03-28 19:11:47 +053040 {0, 60, /* 110 -> 6.0x */ 0},
41 {0, 55, /* 011 -> 5.5x */ 0},
42 {0, 50, /* 001 -> 5.0x */ 0},
43 {0, 45, /* 000 -> 4.5x */ 0},
44 {0, 40, /* 010 -> 4.0x */ 0},
45 {0, 35, /* 111 -> 3.5x */ 0},
46 {0, 30, /* 101 -> 3.0x */ 0},
47 {0, 20, /* 100 -> 2.0x */ 0},
48 {0, 0, CPUFREQ_TABLE_END}
Linus Torvalds1da177e2005-04-16 15:20:36 -070049};
50
Mikulas Patocka22c73792013-12-11 19:39:19 -050051static const u8 index_to_register[8] = { 6, 3, 1, 0, 2, 7, 5, 4 };
52static const u8 register_to_index[8] = { 3, 2, 4, 1, 7, 6, 0, 5 };
53
Mikulas Patockad82b9222013-12-11 19:38:53 -050054static const struct {
55 unsigned freq;
56 unsigned mult;
57} usual_frequency_table[] = {
Mikulas Patocka853aa052014-07-09 17:19:04 -040058 { 350000, 35 }, // 100 * 3.5
Mikulas Patockad82b9222013-12-11 19:38:53 -050059 { 400000, 40 }, // 100 * 4
60 { 450000, 45 }, // 100 * 4.5
61 { 475000, 50 }, // 95 * 5
62 { 500000, 50 }, // 100 * 5
63 { 506250, 45 }, // 112.5 * 4.5
64 { 533500, 55 }, // 97 * 5.5
65 { 550000, 55 }, // 100 * 5.5
66 { 562500, 50 }, // 112.5 * 5
67 { 570000, 60 }, // 95 * 6
68 { 600000, 60 }, // 100 * 6
69 { 618750, 55 }, // 112.5 * 5.5
70 { 660000, 55 }, // 120 * 5.5
71 { 675000, 60 }, // 112.5 * 6
72 { 720000, 60 }, // 120 * 6
73};
74
75#define FREQ_RANGE 3000
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
77/**
78 * powernow_k6_get_cpu_multiplier - returns the current FSB multiplier
79 *
Mikulas Patockae20e1d02013-12-11 19:38:32 -050080 * Returns the current setting of the frequency multiplier. Core clock
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 * speed is frequency of the Front-Side Bus multiplied with this value.
82 */
83static int powernow_k6_get_cpu_multiplier(void)
84{
Mikulas Patockae20e1d02013-12-11 19:38:32 -050085 unsigned long invalue = 0;
Dave Jones14a66502009-01-18 00:00:04 -050086 u32 msrval;
Dave Jones32ee8c32006-02-28 00:43:23 -050087
Mikulas Patockae20e1d02013-12-11 19:38:32 -050088 local_irq_disable();
89
Linus Torvalds1da177e2005-04-16 15:20:36 -070090 msrval = POWERNOW_IOPORT + 0x1;
91 wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
Paolo Ciarrocchi8d2d2052008-07-28 21:08:16 +020092 invalue = inl(POWERNOW_IOPORT + 0x8);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 msrval = POWERNOW_IOPORT + 0x0;
94 wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */
95
Mikulas Patockae20e1d02013-12-11 19:38:32 -050096 local_irq_enable();
97
Mikulas Patocka22c73792013-12-11 19:39:19 -050098 return clock_ratio[register_to_index[(invalue >> 5)&7]].driver_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -070099}
100
Mikulas Patockae20e1d02013-12-11 19:38:32 -0500101static void powernow_k6_set_cpu_multiplier(unsigned int best_i)
102{
103 unsigned long outvalue, invalue;
104 unsigned long msrval;
105 unsigned long cr0;
106
107 /* we now need to transform best_i to the BVC format, see AMD#23446 */
108
109 /*
110 * The processor doesn't respond to inquiry cycles while changing the
111 * frequency, so we must disable cache.
112 */
113 local_irq_disable();
114 cr0 = read_cr0();
115 write_cr0(cr0 | X86_CR0_CD);
116 wbinvd();
117
Mikulas Patocka22c73792013-12-11 19:39:19 -0500118 outvalue = (1<<12) | (1<<10) | (1<<9) | (index_to_register[best_i]<<5);
Mikulas Patockae20e1d02013-12-11 19:38:32 -0500119
120 msrval = POWERNOW_IOPORT + 0x1;
121 wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
122 invalue = inl(POWERNOW_IOPORT + 0x8);
123 invalue = invalue & 0x1f;
124 outvalue = outvalue | invalue;
125 outl(outvalue, (POWERNOW_IOPORT + 0x8));
126 msrval = POWERNOW_IOPORT + 0x0;
127 wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */
128
129 write_cr0(cr0);
130 local_irq_enable();
131}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132
133/**
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +0530134 * powernow_k6_target - set the PowerNow! multiplier
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 * @best_i: clock_ratio[best_i] is the target multiplier
136 *
137 * Tries to change the PowerNow! multiplier
138 */
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +0530139static int powernow_k6_target(struct cpufreq_policy *policy,
Viresh Kumarb43a7ff2013-03-24 11:56:43 +0530140 unsigned int best_i)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
Viresh Kumar50701582013-03-30 16:25:15 +0530143 if (clock_ratio[best_i].driver_data > max_multiplier) {
Dave Jones14a66502009-01-18 00:00:04 -0500144 printk(KERN_ERR PFX "invalid target frequency\n");
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +0530145 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 }
147
Mikulas Patockae20e1d02013-12-11 19:38:32 -0500148 powernow_k6_set_cpu_multiplier(best_i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 return 0;
151}
152
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153static int powernow_k6_cpu_init(struct cpufreq_policy *policy)
154{
Stratos Karafotis041526f2014-04-25 23:15:38 +0300155 struct cpufreq_frequency_table *pos;
Dave Jones14a66502009-01-18 00:00:04 -0500156 unsigned int i, f;
Mikulas Patockad82b9222013-12-11 19:38:53 -0500157 unsigned khz;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158
159 if (policy->cpu != 0)
160 return -ENODEV;
161
Mikulas Patockad82b9222013-12-11 19:38:53 -0500162 max_multiplier = 0;
163 khz = cpu_khz;
164 for (i = 0; i < ARRAY_SIZE(usual_frequency_table); i++) {
165 if (khz >= usual_frequency_table[i].freq - FREQ_RANGE &&
166 khz <= usual_frequency_table[i].freq + FREQ_RANGE) {
167 khz = usual_frequency_table[i].freq;
168 max_multiplier = usual_frequency_table[i].mult;
169 break;
170 }
171 }
172 if (param_max_multiplier) {
Stratos Karafotis041526f2014-04-25 23:15:38 +0300173 cpufreq_for_each_entry(pos, clock_ratio)
174 if (pos->driver_data == param_max_multiplier) {
Mikulas Patockad82b9222013-12-11 19:38:53 -0500175 max_multiplier = param_max_multiplier;
176 goto have_max_multiplier;
177 }
Mikulas Patockad82b9222013-12-11 19:38:53 -0500178 printk(KERN_ERR "powernow-k6: invalid max_multiplier parameter, valid parameters 20, 30, 35, 40, 45, 50, 55, 60\n");
179 return -EINVAL;
180 }
181
182 if (!max_multiplier) {
183 printk(KERN_WARNING "powernow-k6: unknown frequency %u, cannot determine current multiplier\n", khz);
184 printk(KERN_WARNING "powernow-k6: use module parameters max_multiplier and bus_frequency\n");
185 return -EOPNOTSUPP;
186 }
187
188have_max_multiplier:
189 param_max_multiplier = max_multiplier;
190
191 if (param_busfreq) {
192 if (param_busfreq >= 50000 && param_busfreq <= 150000) {
193 busfreq = param_busfreq / 10;
194 goto have_busfreq;
195 }
196 printk(KERN_ERR "powernow-k6: invalid bus_frequency parameter, allowed range 50000 - 150000 kHz\n");
197 return -EINVAL;
198 }
199
200 busfreq = khz / max_multiplier;
201have_busfreq:
202 param_busfreq = busfreq * 10;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203
204 /* table init */
Stratos Karafotis041526f2014-04-25 23:15:38 +0300205 cpufreq_for_each_entry(pos, clock_ratio) {
206 f = pos->driver_data;
Dave Jones14a66502009-01-18 00:00:04 -0500207 if (f > max_multiplier)
Stratos Karafotis041526f2014-04-25 23:15:38 +0300208 pos->frequency = CPUFREQ_ENTRY_INVALID;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 else
Stratos Karafotis041526f2014-04-25 23:15:38 +0300210 pos->frequency = busfreq * f;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 }
212
213 /* cpuinfo and default policy values */
Mikulas Patockae20e1d02013-12-11 19:38:32 -0500214 policy->cpuinfo.transition_latency = 500000;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
Viresh Kumarb1474052013-09-16 18:56:27 +0530216 return cpufreq_table_validate_and_show(policy, clock_ratio);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217}
218
219
220static int powernow_k6_cpu_exit(struct cpufreq_policy *policy)
221{
222 unsigned int i;
Srivatsa S. Bhat237ede12014-04-29 00:24:27 +0530223
224 for (i = 0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) {
Srivatsa S. Bhat3221e552014-04-29 00:24:42 +0530225 if (clock_ratio[i].driver_data == max_multiplier) {
226 struct cpufreq_freqs freqs;
227
228 freqs.old = policy->cur;
229 freqs.new = clock_ratio[i].frequency;
230 freqs.flags = 0;
231
232 cpufreq_freq_transition_begin(policy, &freqs);
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +0530233 powernow_k6_target(policy, i);
Srivatsa S. Bhat3221e552014-04-29 00:24:42 +0530234 cpufreq_freq_transition_end(policy, &freqs, 0);
235 break;
236 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 }
Dave Jones32ee8c32006-02-28 00:43:23 -0500238 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239}
240
241static unsigned int powernow_k6_get(unsigned int cpu)
242{
Dave Jones14a66502009-01-18 00:00:04 -0500243 unsigned int ret;
244 ret = (busfreq * powernow_k6_get_cpu_multiplier());
245 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246}
247
Linus Torvalds221dee22007-02-26 14:55:48 -0800248static struct cpufreq_driver powernow_k6_driver = {
Viresh Kumard63bd272013-10-03 20:28:17 +0530249 .verify = cpufreq_generic_frequency_table_verify,
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +0530250 .target_index = powernow_k6_target,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 .init = powernow_k6_cpu_init,
252 .exit = powernow_k6_cpu_exit,
253 .get = powernow_k6_get,
254 .name = "powernow-k6",
Viresh Kumard63bd272013-10-03 20:28:17 +0530255 .attr = cpufreq_generic_attr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256};
257
Andi Kleenfa8031a2012-01-26 00:09:12 +0100258static const struct x86_cpu_id powernow_k6_ids[] = {
259 { X86_VENDOR_AMD, 5, 12 },
260 { X86_VENDOR_AMD, 5, 13 },
261 {}
262};
Ben Hutchingsb4d2d232012-02-11 23:04:12 +0000263MODULE_DEVICE_TABLE(x86cpu, powernow_k6_ids);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264
265/**
266 * powernow_k6_init - initializes the k6 PowerNow! CPUFreq driver
267 *
268 * Initializes the K6 PowerNow! support. Returns -ENODEV on unsupported
269 * devices, -EINVAL or -ENOMEM on problems during initiatization, and zero
270 * on success.
271 */
272static int __init powernow_k6_init(void)
Dave Jones32ee8c32006-02-28 00:43:23 -0500273{
Andi Kleenfa8031a2012-01-26 00:09:12 +0100274 if (!x86_match_cpu(powernow_k6_ids))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 return -ENODEV;
276
277 if (!request_region(POWERNOW_IOPORT, 16, "PowerNow!")) {
Dave Jones14a66502009-01-18 00:00:04 -0500278 printk(KERN_INFO PFX "PowerNow IOPORT region already used.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 return -EIO;
280 }
281
282 if (cpufreq_register_driver(&powernow_k6_driver)) {
Paolo Ciarrocchi8d2d2052008-07-28 21:08:16 +0200283 release_region(POWERNOW_IOPORT, 16);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 return -EINVAL;
285 }
286
287 return 0;
288}
289
290
291/**
292 * powernow_k6_exit - unregisters AMD K6-2+/3+ PowerNow! support
293 *
294 * Unregisters AMD K6-2+ / K6-3+ PowerNow! support.
295 */
296static void __exit powernow_k6_exit(void)
297{
298 cpufreq_unregister_driver(&powernow_k6_driver);
Paolo Ciarrocchi8d2d2052008-07-28 21:08:16 +0200299 release_region(POWERNOW_IOPORT, 16);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300}
301
302
Dave Jonesd5e80b42014-12-19 11:20:43 -0500303MODULE_AUTHOR("Arjan van de Ven, Dave Jones, "
Dave Jones14a66502009-01-18 00:00:04 -0500304 "Dominik Brodowski <linux@brodo.de>");
Paolo Ciarrocchi8d2d2052008-07-28 21:08:16 +0200305MODULE_DESCRIPTION("PowerNow! driver for AMD K6-2+ / K6-3+ processors.");
306MODULE_LICENSE("GPL");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307
308module_init(powernow_k6_init);
309module_exit(powernow_k6_exit);