/* * (C) 2001 Dave Jones, Arjan van de ven. * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> * * Licensed under the terms of the GNU GPL License version 2. * Based upon reverse engineered information, and on Intel documentation * for chipsets ICH2-M and ICH3-M. * * Many thanks to Ducrot Bruno for finding and fixing the last * "missing link" for ICH2-M/ICH3-M support, and to Thomas Winkler * for extensive testing. * * BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous* */ /********************************************************************* * SPEEDSTEP - DEFINITIONS * *********************************************************************/ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/cpufreq.h> #include <linux/pci.h> #include <linux/slab.h> #include <linux/sched.h> #include "speedstep-lib.h" /* speedstep_chipset: * It is necessary to know which chipset is used. As accesses to * this device occur at various places in this module, we need a * static struct pci_dev * pointing to that device. */ static struct pci_dev *speedstep_chipset_dev; /* speedstep_processor */ static unsigned int speedstep_processor = 0; static u32 pmbase; /* * There are only two frequency states for each processor. Values * are in kHz for the time being. */ static struct cpufreq_frequency_table speedstep_freqs[] = { {SPEEDSTEP_HIGH, 0}, {SPEEDSTEP_LOW, 0}, {0, CPUFREQ_TABLE_END}, }; #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "speedstep-ich", msg) /** * speedstep_find_register - read the PMBASE address * * Returns: -ENODEV if no register could be found */ static int speedstep_find_register (void) { if (!speedstep_chipset_dev) return -ENODEV; /* get PMBASE */ pci_read_config_dword(speedstep_chipset_dev, 0x40, &pmbase); if (!(pmbase & 0x01)) { printk(KERN_ERR "speedstep-ich: could not find speedstep register\n"); return -ENODEV; } pmbase &= 0xFFFFFFFE; if (!pmbase) { printk(KERN_ERR "speedstep-ich: could not find speedstep register\n"); return -ENODEV; } dprintk("pmbase is 0x%x\n", pmbase); return 0; } /** * speedstep_set_state - set the SpeedStep state * @state: new processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH) * * Tries to change the SpeedStep state. */ static void speedstep_set_state (unsigned int state) { u8 pm2_blk; u8 value; unsigned long flags; if (state > 0x1) return; /* Disable IRQs */ local_irq_save(flags); /* read state */ value = inb(pmbase + 0x50); dprintk("read at pmbase 0x%x + 0x50 returned 0x%x\n", pmbase, value); /* write new state */ value &= 0xFE; value |= state; dprintk("writing 0x%x to pmbase 0x%x + 0x50\n", value, pmbase); /* Disable bus master arbitration */ pm2_blk = inb(pmbase + 0x20); pm2_blk |= 0x01; outb(pm2_blk, (pmbase + 0x20)); /* Actual transition */ outb(value, (pmbase + 0x50)); /* Restore bus master arbitration */ pm2_blk &= 0xfe; outb(pm2_blk, (pmbase + 0x20)); /* check if transition was successful */ value = inb(pmbase + 0x50); /* Enable IRQs */ local_irq_restore(flags); dprintk("read at pmbase 0x%x + 0x50 returned 0x%x\n", pmbase, value); if (state == (value & 0x1)) { dprintk("change to %u MHz succeeded\n", (speedstep_get_processor_frequency(speedstep_processor) / 1000)); } else { printk (KERN_ERR "cpufreq: change failed - I/O error\n"); } return; } /** * speedstep_activate - activate SpeedStep control in the chipset * * Tries to activate the SpeedStep status and control registers. * Returns -EINVAL on an unsupported chipset, and zero on success. */ static int speedstep_activate (void) { u16 value = 0; if (!speedstep_chipset_dev) return -EINVAL; pci_read_config_word(speedstep_chipset_dev, 0x00A0, &value); if (!(value & 0x08)) { value |= 0x08; dprintk("activating SpeedStep (TM) registers\n"); pci_write_config_word(speedstep_chipset_dev, 0x00A0, value); } return 0; } /** * speedstep_detect_chipset - detect the Southbridge which contains SpeedStep logic * * Detects ICH2-M, ICH3-M and ICH4-M so far. The pci_dev points to * the LPC bridge / PM module which contains all power-management * functions. Returns the SPEEDSTEP_CHIPSET_-number for the detected * chipset, or zero on failure. */ static unsigned int speedstep_detect_chipset (void) { speedstep_chipset_dev = pci_get_subsys(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801DB_12, PCI_ANY_ID, PCI_ANY_ID, NULL); if (speedstep_chipset_dev) return 4; /* 4-M */ speedstep_chipset_dev = pci_get_subsys(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801CA_12, PCI_ANY_ID, PCI_ANY_ID, NULL); if (speedstep_chipset_dev) return 3; /* 3-M */ speedstep_chipset_dev = pci_get_subsys(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801BA_10, PCI_ANY_ID, PCI_ANY_ID, NULL); if (speedstep_chipset_dev) { /* speedstep.c causes lockups on Dell Inspirons 8000 and * 8100 which use a pretty old revision of the 82815 * host brige. Abort on these systems. */ static struct pci_dev *hostbridge; hostbridge = pci_get_subsys(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82815_MC, PCI_ANY_ID, PCI_ANY_ID, NULL); if (!hostbridge) return 2; /* 2-M */ if (hostbridge->revision < 5) { dprintk("hostbridge does not support speedstep\n"); speedstep_chipset_dev = NULL; pci_dev_put(hostbridge); return 0; } pci_dev_put(hostbridge); return 2; /* 2-M */ } return 0; } static unsigned int _speedstep_get(cpumask_t cpus) { unsigned int speed; cpumask_t cpus_allowed; cpus_allowed = current->cpus_allowed; set_cpus_allowed(current, cpus); speed = speedstep_get_processor_frequency(speedstep_processor); set_cpus_allowed(current, cpus_allowed); dprintk("detected %u kHz as current frequency\n", speed); return speed; } static unsigned int speedstep_get(unsigned int cpu) { return _speedstep_get(cpumask_of_cpu(cpu)); } /** * speedstep_target - set 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 speedstep_target (struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation) { unsigned int newstate = 0; struct cpufreq_freqs freqs; cpumask_t cpus_allowed; int i; if (cpufreq_frequency_table_target(policy, &speedstep_freqs[0], target_freq, relation, &newstate)) return -EINVAL; freqs.old = _speedstep_get(policy->cpus); freqs.new = speedstep_freqs[newstate].frequency; freqs.cpu = policy->cpu; dprintk("transiting from %u to %u kHz\n", freqs.old, freqs.new); /* no transition necessary */ if (freqs.old == freqs.new) return 0; cpus_allowed = current->cpus_allowed; for_each_cpu_mask(i, policy->cpus) { freqs.cpu = i; cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); } /* switch to physical CPU where state is to be changed */ set_cpus_allowed(current, policy->cpus); speedstep_set_state(newstate); /* allow to be run on all CPUs */ set_cpus_allowed(current, cpus_allowed); for_each_cpu_mask(i, policy->cpus) { freqs.cpu = i; cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); } return 0; } /** * speedstep_verify - verifies a new CPUFreq policy * @policy: new policy * * Limit must be within speedstep_low_freq and speedstep_high_freq, with * at least one border included. */ static int speedstep_verify (struct cpufreq_policy *policy) { return cpufreq_frequency_table_verify(policy, &speedstep_freqs[0]); } static int speedstep_cpu_init(struct cpufreq_policy *policy) { int result = 0; unsigned int speed; cpumask_t cpus_allowed; /* only run on CPU to be set, or on its sibling */ #ifdef CONFIG_SMP policy->cpus = cpu_sibling_map[policy->cpu]; #endif cpus_allowed = current->cpus_allowed; set_cpus_allowed(current, policy->cpus); /* detect low and high frequency and transition latency */ result = speedstep_get_freqs(speedstep_processor, &speedstep_freqs[SPEEDSTEP_LOW].frequency, &speedstep_freqs[SPEEDSTEP_HIGH].frequency, &policy->cpuinfo.transition_latency, &speedstep_set_state); set_cpus_allowed(current, cpus_allowed); if (result) return result; /* get current speed setting */ speed = _speedstep_get(policy->cpus); if (!speed) return -EIO; dprintk("currently at %s speed setting - %i MHz\n", (speed == speedstep_freqs[SPEEDSTEP_LOW].frequency) ? "low" : "high", (speed / 1000)); /* cpuinfo and default policy values */ policy->governor = CPUFREQ_DEFAULT_GOVERNOR; policy->cur = speed; result = cpufreq_frequency_table_cpuinfo(policy, speedstep_freqs); if (result) return (result); cpufreq_frequency_table_get_attr(speedstep_freqs, policy->cpu); return 0; } static int speedstep_cpu_exit(struct cpufreq_policy *policy) { cpufreq_frequency_table_put_attr(policy->cpu); return 0; } static struct freq_attr* speedstep_attr[] = { &cpufreq_freq_attr_scaling_available_freqs, NULL, }; static struct cpufreq_driver speedstep_driver = { .name = "speedstep-ich", .verify = speedstep_verify, .target = speedstep_target, .init = speedstep_cpu_init, .exit = speedstep_cpu_exit, .get = speedstep_get, .owner = THIS_MODULE, .attr = speedstep_attr, }; /** * speedstep_init - initializes the SpeedStep CPUFreq driver * * Initializes the SpeedStep support. Returns -ENODEV on unsupported * devices, -EINVAL on problems during initiatization, and zero on * success. */ static int __init speedstep_init(void) { /* detect processor */ speedstep_processor = speedstep_detect_processor(); if (!speedstep_processor) { dprintk("Intel(R) SpeedStep(TM) capable processor not found\n"); return -ENODEV; } /* detect chipset */ if (!speedstep_detect_chipset()) { dprintk("Intel(R) SpeedStep(TM) for this chipset not (yet) available.\n"); return -ENODEV; } /* activate speedstep support */ if (speedstep_activate()) { pci_dev_put(speedstep_chipset_dev); return -EINVAL; } if (speedstep_find_register()) return -ENODEV; return cpufreq_register_driver(&speedstep_driver); } /** * speedstep_exit - unregisters SpeedStep support * * Unregisters SpeedStep support. */ static void __exit speedstep_exit(void) { pci_dev_put(speedstep_chipset_dev); cpufreq_unregister_driver(&speedstep_driver); } MODULE_AUTHOR ("Dave Jones <davej@codemonkey.org.uk>, Dominik Brodowski <linux@brodo.de>"); MODULE_DESCRIPTION ("Speedstep driver for Intel mobile processors on chipsets with ICH-M southbridges."); MODULE_LICENSE ("GPL"); module_init(speedstep_init); module_exit(speedstep_exit);