Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * This file was based upon code in Powertweak Linux (http://powertweak.sf.net) |
| 3 | * (C) 2000-2003 Dave Jones, Arjan van de Ven, Janne Pänkälä, Dominik Brodowski. |
| 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> |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame^] | 11 | #include <linux/module.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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; |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame^] | 53 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 */ |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame^] | 84 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 */ |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame^] | 155 | for (i=0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 */ |
| 163 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; |
| 164 | policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; |
| 165 | policy->cur = busfreq * max_multiplier; |
| 166 | |
| 167 | result = cpufreq_frequency_table_cpuinfo(policy, clock_ratio); |
| 168 | if (result) |
| 169 | return (result); |
| 170 | |
| 171 | cpufreq_frequency_table_get_attr(clock_ratio, policy->cpu); |
| 172 | |
| 173 | return 0; |
| 174 | } |
| 175 | |
| 176 | |
| 177 | static int powernow_k6_cpu_exit(struct cpufreq_policy *policy) |
| 178 | { |
| 179 | unsigned int i; |
| 180 | for (i=0; i<8; i++) { |
| 181 | if (i==max_multiplier) |
| 182 | powernow_k6_set_state(i); |
| 183 | } |
| 184 | cpufreq_frequency_table_put_attr(policy->cpu); |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame^] | 185 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 186 | } |
| 187 | |
| 188 | static unsigned int powernow_k6_get(unsigned int cpu) |
| 189 | { |
| 190 | return busfreq * powernow_k6_get_cpu_multiplier(); |
| 191 | } |
| 192 | |
| 193 | static struct freq_attr* powernow_k6_attr[] = { |
| 194 | &cpufreq_freq_attr_scaling_available_freqs, |
| 195 | NULL, |
| 196 | }; |
| 197 | |
| 198 | static struct cpufreq_driver powernow_k6_driver = { |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame^] | 199 | .verify = powernow_k6_verify, |
| 200 | .target = powernow_k6_target, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 201 | .init = powernow_k6_cpu_init, |
| 202 | .exit = powernow_k6_cpu_exit, |
| 203 | .get = powernow_k6_get, |
| 204 | .name = "powernow-k6", |
| 205 | .owner = THIS_MODULE, |
| 206 | .attr = powernow_k6_attr, |
| 207 | }; |
| 208 | |
| 209 | |
| 210 | /** |
| 211 | * powernow_k6_init - initializes the k6 PowerNow! CPUFreq driver |
| 212 | * |
| 213 | * Initializes the K6 PowerNow! support. Returns -ENODEV on unsupported |
| 214 | * devices, -EINVAL or -ENOMEM on problems during initiatization, and zero |
| 215 | * on success. |
| 216 | */ |
| 217 | static int __init powernow_k6_init(void) |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame^] | 218 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 219 | struct cpuinfo_x86 *c = cpu_data; |
| 220 | |
| 221 | if ((c->x86_vendor != X86_VENDOR_AMD) || (c->x86 != 5) || |
| 222 | ((c->x86_model != 12) && (c->x86_model != 13))) |
| 223 | return -ENODEV; |
| 224 | |
| 225 | if (!request_region(POWERNOW_IOPORT, 16, "PowerNow!")) { |
| 226 | printk("cpufreq: PowerNow IOPORT region already used.\n"); |
| 227 | return -EIO; |
| 228 | } |
| 229 | |
| 230 | if (cpufreq_register_driver(&powernow_k6_driver)) { |
| 231 | release_region (POWERNOW_IOPORT, 16); |
| 232 | return -EINVAL; |
| 233 | } |
| 234 | |
| 235 | return 0; |
| 236 | } |
| 237 | |
| 238 | |
| 239 | /** |
| 240 | * powernow_k6_exit - unregisters AMD K6-2+/3+ PowerNow! support |
| 241 | * |
| 242 | * Unregisters AMD K6-2+ / K6-3+ PowerNow! support. |
| 243 | */ |
| 244 | static void __exit powernow_k6_exit(void) |
| 245 | { |
| 246 | cpufreq_unregister_driver(&powernow_k6_driver); |
| 247 | release_region (POWERNOW_IOPORT, 16); |
| 248 | } |
| 249 | |
| 250 | |
| 251 | MODULE_AUTHOR ("Arjan van de Ven <arjanv@redhat.com>, Dave Jones <davej@codemonkey.org.uk>, Dominik Brodowski <linux@brodo.de>"); |
| 252 | MODULE_DESCRIPTION ("PowerNow! driver for AMD K6-2+ / K6-3+ processors."); |
| 253 | MODULE_LICENSE ("GPL"); |
| 254 | |
| 255 | module_init(powernow_k6_init); |
| 256 | module_exit(powernow_k6_exit); |