/* * (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 * *********************************************************************/ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/cpufreq.h> #include <linux/pci.h> #include <linux/sched.h> #include <asm/cpu_device_id.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 enum speedstep_processor speedstep_processor; 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[] = { {0, SPEEDSTEP_HIGH, 0}, {0, SPEEDSTEP_LOW, 0}, {0, 0, CPUFREQ_TABLE_END}, }; /** * 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)) { pr_err("could not find speedstep register\n"); return -ENODEV; } pmbase &= 0xFFFFFFFE; if (!pmbase) { pr_err("could not find speedstep register\n"); return -ENODEV; } pr_debug("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. Can be called from * smp_call_function_single. */ 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); pr_debug("read at pmbase 0x%x + 0x50 returned 0x%x\n", pmbase, value); /* write new state */ value &= 0xFE; value |= state; pr_debug("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); pr_debug("read at pmbase 0x%x + 0x50 returned 0x%x\n", pmbase, value); if (state == (value & 0x1)) pr_debug("change to %u MHz succeeded\n", speedstep_get_frequency(speedstep_processor) / 1000); else pr_err("change failed - I/O error\n"); return; } /* Wrapper for smp_call_function_single. */ static void _speedstep_set_state(void *_state) { speedstep_set_state(*(unsigned int *)_state); } /** * 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; pr_debug("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 bridge. Abort on these systems. */ 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) { pr_debug("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 void get_freq_data(void *_speed) { unsigned int *speed = _speed; *speed = speedstep_get_frequency(speedstep_processor); } static unsigned int speedstep_get(unsigned int cpu) { unsigned int speed; /* You're supposed to ensure CPU is online. */ if (smp_call_function_single(cpu, get_freq_data, &speed, 1) != 0) BUG(); pr_debug("detected %u kHz as current frequency\n", speed); return speed; } /** * speedstep_target - set a new CPUFreq policy * @policy: new policy * @index: index of target frequency * * Sets a new CPUFreq policy. */ static int speedstep_target(struct cpufreq_policy *policy, unsigned int index) { unsigned int policy_cpu; policy_cpu = cpumask_any_and(policy->cpus, cpu_online_mask); smp_call_function_single(policy_cpu, _speedstep_set_state, &index, true); return 0; } struct get_freqs { struct cpufreq_policy *policy; int ret; }; static void get_freqs_on_cpu(void *_get_freqs) { struct get_freqs *get_freqs = _get_freqs; get_freqs->ret = speedstep_get_freqs(speedstep_processor, &speedstep_freqs[SPEEDSTEP_LOW].frequency, &speedstep_freqs[SPEEDSTEP_HIGH].frequency, &get_freqs->policy->cpuinfo.transition_latency, &speedstep_set_state); } static int speedstep_cpu_init(struct cpufreq_policy *policy) { unsigned int policy_cpu; struct get_freqs gf; /* only run on CPU to be set, or on its sibling */ #ifdef CONFIG_SMP cpumask_copy(policy->cpus, topology_sibling_cpumask(policy->cpu)); #endif policy_cpu = cpumask_any_and(policy->cpus, cpu_online_mask); /* detect low and high frequency and transition latency */ gf.policy = policy; smp_call_function_single(policy_cpu, get_freqs_on_cpu, &gf, 1); if (gf.ret) return gf.ret; return cpufreq_table_validate_and_show(policy, speedstep_freqs); } static struct cpufreq_driver speedstep_driver = { .name = "speedstep-ich", .verify = cpufreq_generic_frequency_table_verify, .target_index = speedstep_target, .init = speedstep_cpu_init, .get = speedstep_get, .attr = cpufreq_generic_attr, }; static const struct x86_cpu_id ss_smi_ids[] = { { X86_VENDOR_INTEL, 6, 0xb, }, { X86_VENDOR_INTEL, 6, 0x8, }, { X86_VENDOR_INTEL, 15, 2 }, {} }; #if 0 /* Autoload or not? Do not for now. */ MODULE_DEVICE_TABLE(x86cpu, ss_smi_ids); #endif /** * 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) { if (!x86_match_cpu(ss_smi_ids)) return -ENODEV; /* detect processor */ speedstep_processor = speedstep_detect_processor(); if (!speedstep_processor) { pr_debug("Intel(R) SpeedStep(TM) capable processor " "not found\n"); return -ENODEV; } /* detect chipset */ if (!speedstep_detect_chipset()) { pr_debug("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, 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);