| 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, |
| 4 | * Dominik Brodowski. |
| 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> |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/init.h> |
| 14 | #include <linux/cpufreq.h> |
| 15 | #include <linux/ioport.h> |
| 16 | #include <linux/timex.h> |
| 17 | #include <linux/io.h> |
| 18 | |
| 19 | #include <asm/cpu_device_id.h> |
| 20 | #include <asm/msr.h> |
| 21 | |
| 22 | #define POWERNOW_IOPORT 0xfff0 /* it doesn't matter where, as long |
| 23 | as it is unused */ |
| 24 | |
| 25 | #define PFX "powernow-k6: " |
| 26 | static unsigned int busfreq; /* FSB, in 10 kHz */ |
| 27 | static unsigned int max_multiplier; |
| 28 | |
| 29 | static unsigned int param_busfreq = 0; |
| 30 | static unsigned int param_max_multiplier = 0; |
| 31 | |
| 32 | module_param_named(max_multiplier, param_max_multiplier, uint, S_IRUGO); |
| 33 | MODULE_PARM_DESC(max_multiplier, "Maximum multiplier (allowed values: 20 30 35 40 45 50 55 60)"); |
| 34 | |
| 35 | module_param_named(bus_frequency, param_busfreq, uint, S_IRUGO); |
| 36 | MODULE_PARM_DESC(bus_frequency, "Bus frequency in kHz"); |
| 37 | |
| 38 | /* Clock ratio multiplied by 10 - see table 27 in AMD#23446 */ |
| 39 | static struct cpufreq_frequency_table clock_ratio[] = { |
| 40 | {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} |
| 49 | }; |
| 50 | |
| 51 | static const u8 index_to_register[8] = { 6, 3, 1, 0, 2, 7, 5, 4 }; |
| 52 | static const u8 register_to_index[8] = { 3, 2, 4, 1, 7, 6, 0, 5 }; |
| 53 | |
| 54 | static const struct { |
| 55 | unsigned freq; |
| 56 | unsigned mult; |
| 57 | } usual_frequency_table[] = { |
| 58 | { 350000, 35 }, // 100 * 3.5 |
| 59 | { 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 |
| 76 | |
| 77 | /** |
| 78 | * powernow_k6_get_cpu_multiplier - returns the current FSB multiplier |
| 79 | * |
| 80 | * Returns the current setting of the frequency multiplier. Core clock |
| 81 | * speed is frequency of the Front-Side Bus multiplied with this value. |
| 82 | */ |
| 83 | static int powernow_k6_get_cpu_multiplier(void) |
| 84 | { |
| 85 | unsigned long invalue = 0; |
| 86 | u32 msrval; |
| 87 | |
| 88 | local_irq_disable(); |
| 89 | |
| 90 | msrval = POWERNOW_IOPORT + 0x1; |
| 91 | wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */ |
| 92 | invalue = inl(POWERNOW_IOPORT + 0x8); |
| 93 | msrval = POWERNOW_IOPORT + 0x0; |
| 94 | wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */ |
| 95 | |
| 96 | local_irq_enable(); |
| 97 | |
| 98 | return clock_ratio[register_to_index[(invalue >> 5)&7]].driver_data; |
| 99 | } |
| 100 | |
| 101 | static 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 | |
| 118 | outvalue = (1<<12) | (1<<10) | (1<<9) | (index_to_register[best_i]<<5); |
| 119 | |
| 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 | } |
| 132 | |
| 133 | /** |
| 134 | * powernow_k6_target - set the PowerNow! multiplier |
| 135 | * @best_i: clock_ratio[best_i] is the target multiplier |
| 136 | * |
| 137 | * Tries to change the PowerNow! multiplier |
| 138 | */ |
| 139 | static int powernow_k6_target(struct cpufreq_policy *policy, |
| 140 | unsigned int best_i) |
| 141 | { |
| 142 | |
| 143 | if (clock_ratio[best_i].driver_data > max_multiplier) { |
| 144 | printk(KERN_ERR PFX "invalid target frequency\n"); |
| 145 | return -EINVAL; |
| 146 | } |
| 147 | |
| 148 | powernow_k6_set_cpu_multiplier(best_i); |
| 149 | |
| 150 | return 0; |
| 151 | } |
| 152 | |
| 153 | static int powernow_k6_cpu_init(struct cpufreq_policy *policy) |
| 154 | { |
| 155 | struct cpufreq_frequency_table *pos; |
| 156 | unsigned int i, f; |
| 157 | unsigned khz; |
| 158 | |
| 159 | if (policy->cpu != 0) |
| 160 | return -ENODEV; |
| 161 | |
| 162 | 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) { |
| 173 | cpufreq_for_each_entry(pos, clock_ratio) |
| 174 | if (pos->driver_data == param_max_multiplier) { |
| 175 | max_multiplier = param_max_multiplier; |
| 176 | goto have_max_multiplier; |
| 177 | } |
| 178 | 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 | |
| 188 | have_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; |
| 201 | have_busfreq: |
| 202 | param_busfreq = busfreq * 10; |
| 203 | |
| 204 | /* table init */ |
| 205 | cpufreq_for_each_entry(pos, clock_ratio) { |
| 206 | f = pos->driver_data; |
| 207 | if (f > max_multiplier) |
| 208 | pos->frequency = CPUFREQ_ENTRY_INVALID; |
| 209 | else |
| 210 | pos->frequency = busfreq * f; |
| 211 | } |
| 212 | |
| 213 | /* cpuinfo and default policy values */ |
| 214 | policy->cpuinfo.transition_latency = 500000; |
| 215 | |
| 216 | return cpufreq_table_validate_and_show(policy, clock_ratio); |
| 217 | } |
| 218 | |
| 219 | |
| 220 | static int powernow_k6_cpu_exit(struct cpufreq_policy *policy) |
| 221 | { |
| 222 | unsigned int i; |
| 223 | |
| 224 | for (i = 0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) { |
| 225 | 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); |
| 233 | powernow_k6_target(policy, i); |
| 234 | cpufreq_freq_transition_end(policy, &freqs, 0); |
| 235 | break; |
| 236 | } |
| 237 | } |
| 238 | return 0; |
| 239 | } |
| 240 | |
| 241 | static unsigned int powernow_k6_get(unsigned int cpu) |
| 242 | { |
| 243 | unsigned int ret; |
| 244 | ret = (busfreq * powernow_k6_get_cpu_multiplier()); |
| 245 | return ret; |
| 246 | } |
| 247 | |
| 248 | static struct cpufreq_driver powernow_k6_driver = { |
| 249 | .verify = cpufreq_generic_frequency_table_verify, |
| 250 | .target_index = powernow_k6_target, |
| 251 | .init = powernow_k6_cpu_init, |
| 252 | .exit = powernow_k6_cpu_exit, |
| 253 | .get = powernow_k6_get, |
| 254 | .name = "powernow-k6", |
| 255 | .attr = cpufreq_generic_attr, |
| 256 | }; |
| 257 | |
| 258 | static const struct x86_cpu_id powernow_k6_ids[] = { |
| 259 | { X86_VENDOR_AMD, 5, 12 }, |
| 260 | { X86_VENDOR_AMD, 5, 13 }, |
| 261 | {} |
| 262 | }; |
| 263 | MODULE_DEVICE_TABLE(x86cpu, powernow_k6_ids); |
| 264 | |
| 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 | */ |
| 272 | static int __init powernow_k6_init(void) |
| 273 | { |
| 274 | if (!x86_match_cpu(powernow_k6_ids)) |
| 275 | return -ENODEV; |
| 276 | |
| 277 | if (!request_region(POWERNOW_IOPORT, 16, "PowerNow!")) { |
| 278 | printk(KERN_INFO PFX "PowerNow IOPORT region already used.\n"); |
| 279 | return -EIO; |
| 280 | } |
| 281 | |
| 282 | if (cpufreq_register_driver(&powernow_k6_driver)) { |
| 283 | release_region(POWERNOW_IOPORT, 16); |
| 284 | 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 | */ |
| 296 | static void __exit powernow_k6_exit(void) |
| 297 | { |
| 298 | cpufreq_unregister_driver(&powernow_k6_driver); |
| 299 | release_region(POWERNOW_IOPORT, 16); |
| 300 | } |
| 301 | |
| 302 | |
| 303 | MODULE_AUTHOR("Arjan van de Ven, Dave Jones, " |
| 304 | "Dominik Brodowski <linux@brodo.de>"); |
| 305 | MODULE_DESCRIPTION("PowerNow! driver for AMD K6-2+ / K6-3+ processors."); |
| 306 | MODULE_LICENSE("GPL"); |
| 307 | |
| 308 | module_init(powernow_k6_init); |
| 309 | module_exit(powernow_k6_exit); |