/* * This file was based upon code in Powertweak Linux (http://powertweak.sf.net) * (C) 2000-2003 Dave Jones, Arjan van de Ven, Janne Pänkälä, * Dominik Brodowski. * * Licensed under the terms of the GNU GPL License version 2. * * BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous* */ #include #include #include #include #include #include #include #include #include #define POWERNOW_IOPORT 0xfff0 /* it doesn't matter where, as long as it is unused */ #define PFX "powernow-k6: " static unsigned int busfreq; /* FSB, in 10 kHz */ static unsigned int max_multiplier; /* Clock ratio multiplied by 10 - see table 27 in AMD#23446 */ static struct cpufreq_frequency_table clock_ratio[] = { {45, /* 000 -> 4.5x */ 0}, {50, /* 001 -> 5.0x */ 0}, {40, /* 010 -> 4.0x */ 0}, {55, /* 011 -> 5.5x */ 0}, {20, /* 100 -> 2.0x */ 0}, {30, /* 101 -> 3.0x */ 0}, {60, /* 110 -> 6.0x */ 0}, {35, /* 111 -> 3.5x */ 0}, {0, CPUFREQ_TABLE_END} }; /** * powernow_k6_get_cpu_multiplier - returns the current FSB multiplier * * Returns the current setting of the frequency multiplier. Core clock * speed is frequency of the Front-Side Bus multiplied with this value. */ static int powernow_k6_get_cpu_multiplier(void) { u64 invalue = 0; u32 msrval; msrval = POWERNOW_IOPORT + 0x1; wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */ invalue = inl(POWERNOW_IOPORT + 0x8); msrval = POWERNOW_IOPORT + 0x0; wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */ return clock_ratio[(invalue >> 5)&7].index; } /** * powernow_k6_set_state - set the PowerNow! multiplier * @best_i: clock_ratio[best_i] is the target multiplier * * Tries to change the PowerNow! multiplier */ static void powernow_k6_set_state(struct cpufreq_policy *policy, unsigned int best_i) { unsigned long outvalue = 0, invalue = 0; unsigned long msrval; struct cpufreq_freqs freqs; if (clock_ratio[best_i].index > max_multiplier) { printk(KERN_ERR PFX "invalid target frequency\n"); return; } freqs.old = busfreq * powernow_k6_get_cpu_multiplier(); freqs.new = busfreq * clock_ratio[best_i].index; cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); /* we now need to transform best_i to the BVC format, see AMD#23446 */ outvalue = (1<<12) | (1<<10) | (1<<9) | (best_i<<5); msrval = POWERNOW_IOPORT + 0x1; wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */ invalue = inl(POWERNOW_IOPORT + 0x8); invalue = invalue & 0xf; outvalue = outvalue | invalue; outl(outvalue , (POWERNOW_IOPORT + 0x8)); msrval = POWERNOW_IOPORT + 0x0; wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */ cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); return; } /** * powernow_k6_verify - verifies a new CPUfreq policy * @policy: new policy * * Policy must be within lowest and highest possible CPU Frequency, * and at least one possible state must be within min and max. */ static int powernow_k6_verify(struct cpufreq_policy *policy) { return cpufreq_frequency_table_verify(policy, &clock_ratio[0]); } /** * powernow_k6_setpolicy - sets a new CPUFreq policy * @policy: new policy * @target_freq: the target frequency * @relation: how that frequency relates to achieved frequency * (CPUFREQ_RELATION_L or CPUFREQ_RELATION_H) * * sets a new CPUFreq policy */ static int powernow_k6_target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation) { unsigned int newstate = 0; if (cpufreq_frequency_table_target(policy, &clock_ratio[0], target_freq, relation, &newstate)) return -EINVAL; powernow_k6_set_state(policy, newstate); return 0; } static int powernow_k6_cpu_init(struct cpufreq_policy *policy) { unsigned int i, f; int result; if (policy->cpu != 0) return -ENODEV; /* get frequencies */ max_multiplier = powernow_k6_get_cpu_multiplier(); busfreq = cpu_khz / max_multiplier; /* table init */ for (i = 0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) { f = clock_ratio[i].index; if (f > max_multiplier) clock_ratio[i].frequency = CPUFREQ_ENTRY_INVALID; else clock_ratio[i].frequency = busfreq * f; } /* cpuinfo and default policy values */ policy->cpuinfo.transition_latency = 200000; policy->cur = busfreq * max_multiplier; result = cpufreq_frequency_table_cpuinfo(policy, clock_ratio); if (result) return result; cpufreq_frequency_table_get_attr(clock_ratio, policy->cpu); return 0; } static int powernow_k6_cpu_exit(struct cpufreq_policy *policy) { unsigned int i; for (i = 0; i < 8; i++) { if (i == max_multiplier) powernow_k6_set_state(policy, i); } cpufreq_frequency_table_put_attr(policy->cpu); return 0; } static unsigned int powernow_k6_get(unsigned int cpu) { unsigned int ret; ret = (busfreq * powernow_k6_get_cpu_multiplier()); return ret; } static struct freq_attr *powernow_k6_attr[] = { &cpufreq_freq_attr_scaling_available_freqs, NULL, }; static struct cpufreq_driver powernow_k6_driver = { .verify = powernow_k6_verify, .target = powernow_k6_target, .init = powernow_k6_cpu_init, .exit = powernow_k6_cpu_exit, .get = powernow_k6_get, .name = "powernow-k6", .owner = THIS_MODULE, .attr = powernow_k6_attr, }; static const struct x86_cpu_id powernow_k6_ids[] = { { X86_VENDOR_AMD, 5, 12 }, { X86_VENDOR_AMD, 5, 13 }, {} }; MODULE_DEVICE_TABLE(x86cpu, powernow_k6_ids); /** * powernow_k6_init - initializes the k6 PowerNow! CPUFreq driver * * Initializes the K6 PowerNow! support. Returns -ENODEV on unsupported * devices, -EINVAL or -ENOMEM on problems during initiatization, and zero * on success. */ static int __init powernow_k6_init(void) { if (!x86_match_cpu(powernow_k6_ids)) return -ENODEV; if (!request_region(POWERNOW_IOPORT, 16, "PowerNow!")) { printk(KERN_INFO PFX "PowerNow IOPORT region already used.\n"); return -EIO; } if (cpufreq_register_driver(&powernow_k6_driver)) { release_region(POWERNOW_IOPORT, 16); return -EINVAL; } return 0; } /** * powernow_k6_exit - unregisters AMD K6-2+/3+ PowerNow! support * * Unregisters AMD K6-2+ / K6-3+ PowerNow! support. */ static void __exit powernow_k6_exit(void) { cpufreq_unregister_driver(&powernow_k6_driver); release_region(POWERNOW_IOPORT, 16); } MODULE_AUTHOR("Arjan van de Ven, Dave Jones , " "Dominik Brodowski "); MODULE_DESCRIPTION("PowerNow! driver for AMD K6-2+ / K6-3+ processors."); MODULE_LICENSE("GPL"); module_init(powernow_k6_init); module_exit(powernow_k6_exit);