Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
new file mode 100644
index 0000000..b30001f
--- /dev/null
+++ b/drivers/cpufreq/cpufreq.c
@@ -0,0 +1,1428 @@
+/*
+ * linux/drivers/cpufreq/cpufreq.c
+ *
+ * Copyright (C) 2001 Russell King
+ * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/notifier.h>
+#include <linux/cpufreq.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/cpu.h>
+#include <linux/completion.h>
+
+#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, "cpufreq-core", msg)
+
+/**
+ * The "cpufreq driver" - the arch- or hardware-dependend low
+ * level driver of CPUFreq support, and its spinlock. This lock
+ * also protects the cpufreq_cpu_data array.
+ */
+static struct cpufreq_driver *cpufreq_driver;
+static struct cpufreq_policy *cpufreq_cpu_data[NR_CPUS];
+static DEFINE_SPINLOCK(cpufreq_driver_lock);
+
+
+/* we keep a copy of all ->add'ed CPU's struct sys_device here;
+ * as it is only accessed in ->add and ->remove, no lock or reference
+ * count is necessary.
+ */
+static struct sys_device *cpu_sys_devices[NR_CPUS];
+
+
+/* internal prototypes */
+static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event);
+static void handle_update(void *data);
+static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci);
+
+/**
+ * Two notifier lists: the "policy" list is involved in the
+ * validation process for a new CPU frequency policy; the
+ * "transition" list for kernel code that needs to handle
+ * changes to devices when the CPU clock speed changes.
+ * The mutex locks both lists.
+ */
+static struct notifier_block *cpufreq_policy_notifier_list;
+static struct notifier_block *cpufreq_transition_notifier_list;
+static DECLARE_RWSEM (cpufreq_notifier_rwsem);
+
+
+static LIST_HEAD(cpufreq_governor_list);
+static DECLARE_MUTEX (cpufreq_governor_sem);
+
+struct cpufreq_policy * cpufreq_cpu_get(unsigned int cpu)
+{
+ struct cpufreq_policy *data;
+ unsigned long flags;
+
+ if (cpu >= NR_CPUS)
+ goto err_out;
+
+ /* get the cpufreq driver */
+ spin_lock_irqsave(&cpufreq_driver_lock, flags);
+
+ if (!cpufreq_driver)
+ goto err_out_unlock;
+
+ if (!try_module_get(cpufreq_driver->owner))
+ goto err_out_unlock;
+
+
+ /* get the CPU */
+ data = cpufreq_cpu_data[cpu];
+
+ if (!data)
+ goto err_out_put_module;
+
+ if (!kobject_get(&data->kobj))
+ goto err_out_put_module;
+
+
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+ return data;
+
+ err_out_put_module:
+ module_put(cpufreq_driver->owner);
+ err_out_unlock:
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ err_out:
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
+
+void cpufreq_cpu_put(struct cpufreq_policy *data)
+{
+ kobject_put(&data->kobj);
+ module_put(cpufreq_driver->owner);
+}
+EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
+
+
+/*********************************************************************
+ * UNIFIED DEBUG HELPERS *
+ *********************************************************************/
+#ifdef CONFIG_CPU_FREQ_DEBUG
+
+/* what part(s) of the CPUfreq subsystem are debugged? */
+static unsigned int debug;
+
+/* is the debug output ratelimit'ed using printk_ratelimit? User can
+ * set or modify this value.
+ */
+static unsigned int debug_ratelimit = 1;
+
+/* is the printk_ratelimit'ing enabled? It's enabled after a successful
+ * loading of a cpufreq driver, temporarily disabled when a new policy
+ * is set, and disabled upon cpufreq driver removal
+ */
+static unsigned int disable_ratelimit = 1;
+static DEFINE_SPINLOCK(disable_ratelimit_lock);
+
+static inline void cpufreq_debug_enable_ratelimit(void)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&disable_ratelimit_lock, flags);
+ if (disable_ratelimit)
+ disable_ratelimit--;
+ spin_unlock_irqrestore(&disable_ratelimit_lock, flags);
+}
+
+static inline void cpufreq_debug_disable_ratelimit(void)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&disable_ratelimit_lock, flags);
+ disable_ratelimit++;
+ spin_unlock_irqrestore(&disable_ratelimit_lock, flags);
+}
+
+void cpufreq_debug_printk(unsigned int type, const char *prefix, const char *fmt, ...)
+{
+ char s[256];
+ va_list args;
+ unsigned int len;
+ unsigned long flags;
+
+ WARN_ON(!prefix);
+ if (type & debug) {
+ spin_lock_irqsave(&disable_ratelimit_lock, flags);
+ if (!disable_ratelimit && debug_ratelimit && !printk_ratelimit()) {
+ spin_unlock_irqrestore(&disable_ratelimit_lock, flags);
+ return;
+ }
+ spin_unlock_irqrestore(&disable_ratelimit_lock, flags);
+
+ len = snprintf(s, 256, KERN_DEBUG "%s: ", prefix);
+
+ va_start(args, fmt);
+ len += vsnprintf(&s[len], (256 - len), fmt, args);
+ va_end(args);
+
+ printk(s);
+
+ WARN_ON(len < 5);
+ }
+}
+EXPORT_SYMBOL(cpufreq_debug_printk);
+
+
+module_param(debug, uint, 0644);
+MODULE_PARM_DESC(debug, "CPUfreq debugging: add 1 to debug core, 2 to debug drivers, and 4 to debug governors.");
+
+module_param(debug_ratelimit, uint, 0644);
+MODULE_PARM_DESC(debug_ratelimit, "CPUfreq debugging: set to 0 to disable ratelimiting.");
+
+#else /* !CONFIG_CPU_FREQ_DEBUG */
+
+static inline void cpufreq_debug_enable_ratelimit(void) { return; }
+static inline void cpufreq_debug_disable_ratelimit(void) { return; }
+
+#endif /* CONFIG_CPU_FREQ_DEBUG */
+
+
+/*********************************************************************
+ * EXTERNALLY AFFECTING FREQUENCY CHANGES *
+ *********************************************************************/
+
+/**
+ * adjust_jiffies - adjust the system "loops_per_jiffy"
+ *
+ * This function alters the system "loops_per_jiffy" for the clock
+ * speed change. Note that loops_per_jiffy cannot be updated on SMP
+ * systems as each CPU might be scaled differently. So, use the arch
+ * per-CPU loops_per_jiffy value wherever possible.
+ */
+#ifndef CONFIG_SMP
+static unsigned long l_p_j_ref;
+static unsigned int l_p_j_ref_freq;
+
+static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
+{
+ if (ci->flags & CPUFREQ_CONST_LOOPS)
+ return;
+
+ if (!l_p_j_ref_freq) {
+ l_p_j_ref = loops_per_jiffy;
+ l_p_j_ref_freq = ci->old;
+ dprintk("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq);
+ }
+ if ((val == CPUFREQ_PRECHANGE && ci->old < ci->new) ||
+ (val == CPUFREQ_POSTCHANGE && ci->old > ci->new) ||
+ (val == CPUFREQ_RESUMECHANGE)) {
+ loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, ci->new);
+ dprintk("scaling loops_per_jiffy to %lu for frequency %u kHz\n", loops_per_jiffy, ci->new);
+ }
+}
+#else
+static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) { return; }
+#endif
+
+
+/**
+ * cpufreq_notify_transition - call notifier chain and adjust_jiffies on frequency transition
+ *
+ * This function calls the transition notifiers and the "adjust_jiffies" function. It is called
+ * twice on all CPU frequency changes that have external effects.
+ */
+void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state)
+{
+ BUG_ON(irqs_disabled());
+
+ freqs->flags = cpufreq_driver->flags;
+ dprintk("notification %u of frequency transition to %u kHz\n", state, freqs->new);
+
+ down_read(&cpufreq_notifier_rwsem);
+ switch (state) {
+ case CPUFREQ_PRECHANGE:
+ /* detect if the driver reported a value as "old frequency" which
+ * is not equal to what the cpufreq core thinks is "old frequency".
+ */
+ if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
+ if ((likely(cpufreq_cpu_data[freqs->cpu])) &&
+ (likely(cpufreq_cpu_data[freqs->cpu]->cpu == freqs->cpu)) &&
+ (likely(cpufreq_cpu_data[freqs->cpu]->cur)) &&
+ (unlikely(freqs->old != cpufreq_cpu_data[freqs->cpu]->cur)))
+ {
+ printk(KERN_WARNING "Warning: CPU frequency is %u, "
+ "cpufreq assumed %u kHz.\n", freqs->old, cpufreq_cpu_data[freqs->cpu]->cur);
+ freqs->old = cpufreq_cpu_data[freqs->cpu]->cur;
+ }
+ }
+ notifier_call_chain(&cpufreq_transition_notifier_list, CPUFREQ_PRECHANGE, freqs);
+ adjust_jiffies(CPUFREQ_PRECHANGE, freqs);
+ break;
+ case CPUFREQ_POSTCHANGE:
+ adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
+ notifier_call_chain(&cpufreq_transition_notifier_list, CPUFREQ_POSTCHANGE, freqs);
+ if ((likely(cpufreq_cpu_data[freqs->cpu])) &&
+ (likely(cpufreq_cpu_data[freqs->cpu]->cpu == freqs->cpu)))
+ cpufreq_cpu_data[freqs->cpu]->cur = freqs->new;
+ break;
+ }
+ up_read(&cpufreq_notifier_rwsem);
+}
+EXPORT_SYMBOL_GPL(cpufreq_notify_transition);
+
+
+
+/*********************************************************************
+ * SYSFS INTERFACE *
+ *********************************************************************/
+
+/**
+ * cpufreq_parse_governor - parse a governor string
+ */
+static int cpufreq_parse_governor (char *str_governor, unsigned int *policy,
+ struct cpufreq_governor **governor)
+{
+ if (!cpufreq_driver)
+ return -EINVAL;
+ if (cpufreq_driver->setpolicy) {
+ if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
+ *policy = CPUFREQ_POLICY_PERFORMANCE;
+ return 0;
+ } else if (!strnicmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) {
+ *policy = CPUFREQ_POLICY_POWERSAVE;
+ return 0;
+ }
+ return -EINVAL;
+ } else {
+ struct cpufreq_governor *t;
+ down(&cpufreq_governor_sem);
+ if (!cpufreq_driver || !cpufreq_driver->target)
+ goto out;
+ list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
+ if (!strnicmp(str_governor,t->name,CPUFREQ_NAME_LEN)) {
+ *governor = t;
+ up(&cpufreq_governor_sem);
+ return 0;
+ }
+ }
+ out:
+ up(&cpufreq_governor_sem);
+ }
+ return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(cpufreq_parse_governor);
+
+
+/* drivers/base/cpu.c */
+extern struct sysdev_class cpu_sysdev_class;
+
+
+/**
+ * cpufreq_per_cpu_attr_read() / show_##file_name() - print out cpufreq information
+ *
+ * Write out information from cpufreq_driver->policy[cpu]; object must be
+ * "unsigned int".
+ */
+
+#define show_one(file_name, object) \
+static ssize_t show_##file_name \
+(struct cpufreq_policy * policy, char *buf) \
+{ \
+ return sprintf (buf, "%u\n", policy->object); \
+}
+
+show_one(cpuinfo_min_freq, cpuinfo.min_freq);
+show_one(cpuinfo_max_freq, cpuinfo.max_freq);
+show_one(scaling_min_freq, min);
+show_one(scaling_max_freq, max);
+show_one(scaling_cur_freq, cur);
+
+/**
+ * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
+ */
+#define store_one(file_name, object) \
+static ssize_t store_##file_name \
+(struct cpufreq_policy * policy, const char *buf, size_t count) \
+{ \
+ unsigned int ret = -EINVAL; \
+ struct cpufreq_policy new_policy; \
+ \
+ ret = cpufreq_get_policy(&new_policy, policy->cpu); \
+ if (ret) \
+ return -EINVAL; \
+ \
+ ret = sscanf (buf, "%u", &new_policy.object); \
+ if (ret != 1) \
+ return -EINVAL; \
+ \
+ ret = cpufreq_set_policy(&new_policy); \
+ \
+ return ret ? ret : count; \
+}
+
+store_one(scaling_min_freq,min);
+store_one(scaling_max_freq,max);
+
+/**
+ * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
+ */
+static ssize_t show_cpuinfo_cur_freq (struct cpufreq_policy * policy, char *buf)
+{
+ unsigned int cur_freq = cpufreq_get(policy->cpu);
+ if (!cur_freq)
+ return sprintf(buf, "<unknown>");
+ return sprintf(buf, "%u\n", cur_freq);
+}
+
+
+/**
+ * show_scaling_governor - show the current policy for the specified CPU
+ */
+static ssize_t show_scaling_governor (struct cpufreq_policy * policy, char *buf)
+{
+ if(policy->policy == CPUFREQ_POLICY_POWERSAVE)
+ return sprintf(buf, "powersave\n");
+ else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
+ return sprintf(buf, "performance\n");
+ else if (policy->governor)
+ return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", policy->governor->name);
+ return -EINVAL;
+}
+
+
+/**
+ * store_scaling_governor - store policy for the specified CPU
+ */
+static ssize_t store_scaling_governor (struct cpufreq_policy * policy,
+ const char *buf, size_t count)
+{
+ unsigned int ret = -EINVAL;
+ char str_governor[16];
+ struct cpufreq_policy new_policy;
+
+ ret = cpufreq_get_policy(&new_policy, policy->cpu);
+ if (ret)
+ return ret;
+
+ ret = sscanf (buf, "%15s", str_governor);
+ if (ret != 1)
+ return -EINVAL;
+
+ if (cpufreq_parse_governor(str_governor, &new_policy.policy, &new_policy.governor))
+ return -EINVAL;
+
+ ret = cpufreq_set_policy(&new_policy);
+
+ return ret ? ret : count;
+}
+
+/**
+ * show_scaling_driver - show the cpufreq driver currently loaded
+ */
+static ssize_t show_scaling_driver (struct cpufreq_policy * policy, char *buf)
+{
+ return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name);
+}
+
+/**
+ * show_scaling_available_governors - show the available CPUfreq governors
+ */
+static ssize_t show_scaling_available_governors (struct cpufreq_policy * policy,
+ char *buf)
+{
+ ssize_t i = 0;
+ struct cpufreq_governor *t;
+
+ if (!cpufreq_driver->target) {
+ i += sprintf(buf, "performance powersave");
+ goto out;
+ }
+
+ list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
+ if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) - (CPUFREQ_NAME_LEN + 2)))
+ goto out;
+ i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name);
+ }
+ out:
+ i += sprintf(&buf[i], "\n");
+ return i;
+}
+/**
+ * show_affected_cpus - show the CPUs affected by each transition
+ */
+static ssize_t show_affected_cpus (struct cpufreq_policy * policy, char *buf)
+{
+ ssize_t i = 0;
+ unsigned int cpu;
+
+ for_each_cpu_mask(cpu, policy->cpus) {
+ if (i)
+ i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " ");
+ i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu);
+ if (i >= (PAGE_SIZE - 5))
+ break;
+ }
+ i += sprintf(&buf[i], "\n");
+ return i;
+}
+
+
+#define define_one_ro(_name) \
+static struct freq_attr _name = \
+__ATTR(_name, 0444, show_##_name, NULL)
+
+#define define_one_ro0400(_name) \
+static struct freq_attr _name = \
+__ATTR(_name, 0400, show_##_name, NULL)
+
+#define define_one_rw(_name) \
+static struct freq_attr _name = \
+__ATTR(_name, 0644, show_##_name, store_##_name)
+
+define_one_ro0400(cpuinfo_cur_freq);
+define_one_ro(cpuinfo_min_freq);
+define_one_ro(cpuinfo_max_freq);
+define_one_ro(scaling_available_governors);
+define_one_ro(scaling_driver);
+define_one_ro(scaling_cur_freq);
+define_one_ro(affected_cpus);
+define_one_rw(scaling_min_freq);
+define_one_rw(scaling_max_freq);
+define_one_rw(scaling_governor);
+
+static struct attribute * default_attrs[] = {
+ &cpuinfo_min_freq.attr,
+ &cpuinfo_max_freq.attr,
+ &scaling_min_freq.attr,
+ &scaling_max_freq.attr,
+ &affected_cpus.attr,
+ &scaling_governor.attr,
+ &scaling_driver.attr,
+ &scaling_available_governors.attr,
+ NULL
+};
+
+#define to_policy(k) container_of(k,struct cpufreq_policy,kobj)
+#define to_attr(a) container_of(a,struct freq_attr,attr)
+
+static ssize_t show(struct kobject * kobj, struct attribute * attr ,char * buf)
+{
+ struct cpufreq_policy * policy = to_policy(kobj);
+ struct freq_attr * fattr = to_attr(attr);
+ ssize_t ret;
+ policy = cpufreq_cpu_get(policy->cpu);
+ if (!policy)
+ return -EINVAL;
+ ret = fattr->show ? fattr->show(policy,buf) : 0;
+ cpufreq_cpu_put(policy);
+ return ret;
+}
+
+static ssize_t store(struct kobject * kobj, struct attribute * attr,
+ const char * buf, size_t count)
+{
+ struct cpufreq_policy * policy = to_policy(kobj);
+ struct freq_attr * fattr = to_attr(attr);
+ ssize_t ret;
+ policy = cpufreq_cpu_get(policy->cpu);
+ if (!policy)
+ return -EINVAL;
+ ret = fattr->store ? fattr->store(policy,buf,count) : 0;
+ cpufreq_cpu_put(policy);
+ return ret;
+}
+
+static void cpufreq_sysfs_release(struct kobject * kobj)
+{
+ struct cpufreq_policy * policy = to_policy(kobj);
+ dprintk("last reference is dropped\n");
+ complete(&policy->kobj_unregister);
+}
+
+static struct sysfs_ops sysfs_ops = {
+ .show = show,
+ .store = store,
+};
+
+static struct kobj_type ktype_cpufreq = {
+ .sysfs_ops = &sysfs_ops,
+ .default_attrs = default_attrs,
+ .release = cpufreq_sysfs_release,
+};
+
+
+/**
+ * cpufreq_add_dev - add a CPU device
+ *
+ * Adds the cpufreq interface for a CPU device.
+ */
+static int cpufreq_add_dev (struct sys_device * sys_dev)
+{
+ unsigned int cpu = sys_dev->id;
+ int ret = 0;
+ struct cpufreq_policy new_policy;
+ struct cpufreq_policy *policy;
+ struct freq_attr **drv_attr;
+ unsigned long flags;
+ unsigned int j;
+
+ cpufreq_debug_disable_ratelimit();
+ dprintk("adding CPU %u\n", cpu);
+
+#ifdef CONFIG_SMP
+ /* check whether a different CPU already registered this
+ * CPU because it is in the same boat. */
+ policy = cpufreq_cpu_get(cpu);
+ if (unlikely(policy)) {
+ cpu_sys_devices[cpu] = sys_dev;
+ dprintk("CPU already managed, adding link\n");
+ sysfs_create_link(&sys_dev->kobj, &policy->kobj, "cpufreq");
+ cpufreq_debug_enable_ratelimit();
+ return 0;
+ }
+#endif
+
+ if (!try_module_get(cpufreq_driver->owner)) {
+ ret = -EINVAL;
+ goto module_out;
+ }
+
+ policy = kmalloc(sizeof(struct cpufreq_policy), GFP_KERNEL);
+ if (!policy) {
+ ret = -ENOMEM;
+ goto nomem_out;
+ }
+ memset(policy, 0, sizeof(struct cpufreq_policy));
+
+ policy->cpu = cpu;
+ policy->cpus = cpumask_of_cpu(cpu);
+
+ init_MUTEX_LOCKED(&policy->lock);
+ init_completion(&policy->kobj_unregister);
+ INIT_WORK(&policy->update, handle_update, (void *)(long)cpu);
+
+ /* call driver. From then on the cpufreq must be able
+ * to accept all calls to ->verify and ->setpolicy for this CPU
+ */
+ ret = cpufreq_driver->init(policy);
+ if (ret) {
+ dprintk("initialization failed\n");
+ goto err_out;
+ }
+
+ memcpy(&new_policy, policy, sizeof(struct cpufreq_policy));
+
+ /* prepare interface data */
+ policy->kobj.parent = &sys_dev->kobj;
+ policy->kobj.ktype = &ktype_cpufreq;
+ strlcpy(policy->kobj.name, "cpufreq", KOBJ_NAME_LEN);
+
+ ret = kobject_register(&policy->kobj);
+ if (ret)
+ goto err_out;
+
+ /* set up files for this cpu device */
+ drv_attr = cpufreq_driver->attr;
+ while ((drv_attr) && (*drv_attr)) {
+ sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
+ drv_attr++;
+ }
+ if (cpufreq_driver->get)
+ sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
+ if (cpufreq_driver->target)
+ sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
+
+ spin_lock_irqsave(&cpufreq_driver_lock, flags);
+ for_each_cpu_mask(j, policy->cpus)
+ cpufreq_cpu_data[j] = policy;
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ policy->governor = NULL; /* to assure that the starting sequence is
+ * run in cpufreq_set_policy */
+ up(&policy->lock);
+
+ /* set default policy */
+
+ ret = cpufreq_set_policy(&new_policy);
+ if (ret) {
+ dprintk("setting policy failed\n");
+ goto err_out_unregister;
+ }
+
+ module_put(cpufreq_driver->owner);
+ cpu_sys_devices[cpu] = sys_dev;
+ dprintk("initialization complete\n");
+ cpufreq_debug_enable_ratelimit();
+
+ return 0;
+
+
+err_out_unregister:
+ spin_lock_irqsave(&cpufreq_driver_lock, flags);
+ for_each_cpu_mask(j, policy->cpus)
+ cpufreq_cpu_data[j] = NULL;
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+ kobject_unregister(&policy->kobj);
+ wait_for_completion(&policy->kobj_unregister);
+
+err_out:
+ kfree(policy);
+
+nomem_out:
+ module_put(cpufreq_driver->owner);
+ module_out:
+ cpufreq_debug_enable_ratelimit();
+ return ret;
+}
+
+
+/**
+ * cpufreq_remove_dev - remove a CPU device
+ *
+ * Removes the cpufreq interface for a CPU device.
+ */
+static int cpufreq_remove_dev (struct sys_device * sys_dev)
+{
+ unsigned int cpu = sys_dev->id;
+ unsigned long flags;
+ struct cpufreq_policy *data;
+#ifdef CONFIG_SMP
+ unsigned int j;
+#endif
+
+ cpufreq_debug_disable_ratelimit();
+ dprintk("unregistering CPU %u\n", cpu);
+
+ spin_lock_irqsave(&cpufreq_driver_lock, flags);
+ data = cpufreq_cpu_data[cpu];
+
+ if (!data) {
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ cpu_sys_devices[cpu] = NULL;
+ cpufreq_debug_enable_ratelimit();
+ return -EINVAL;
+ }
+ cpufreq_cpu_data[cpu] = NULL;
+
+
+#ifdef CONFIG_SMP
+ /* if this isn't the CPU which is the parent of the kobj, we
+ * only need to unlink, put and exit
+ */
+ if (unlikely(cpu != data->cpu)) {
+ dprintk("removing link\n");
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ sysfs_remove_link(&sys_dev->kobj, "cpufreq");
+ cpu_sys_devices[cpu] = NULL;
+ cpufreq_cpu_put(data);
+ cpufreq_debug_enable_ratelimit();
+ return 0;
+ }
+#endif
+
+ cpu_sys_devices[cpu] = NULL;
+
+ if (!kobject_get(&data->kobj)) {
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ cpufreq_debug_enable_ratelimit();
+ return -EFAULT;
+ }
+
+#ifdef CONFIG_SMP
+ /* if we have other CPUs still registered, we need to unlink them,
+ * or else wait_for_completion below will lock up. Clean the
+ * cpufreq_cpu_data[] while holding the lock, and remove the sysfs
+ * links afterwards.
+ */
+ if (unlikely(cpus_weight(data->cpus) > 1)) {
+ for_each_cpu_mask(j, data->cpus) {
+ if (j == cpu)
+ continue;
+ cpufreq_cpu_data[j] = NULL;
+ }
+ }
+
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+ if (unlikely(cpus_weight(data->cpus) > 1)) {
+ for_each_cpu_mask(j, data->cpus) {
+ if (j == cpu)
+ continue;
+ dprintk("removing link for cpu %u\n", j);
+ sysfs_remove_link(&cpu_sys_devices[j]->kobj, "cpufreq");
+ cpufreq_cpu_put(data);
+ }
+ }
+#else
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+#endif
+
+ down(&data->lock);
+ if (cpufreq_driver->target)
+ __cpufreq_governor(data, CPUFREQ_GOV_STOP);
+ cpufreq_driver->target = NULL;
+ up(&data->lock);
+
+ kobject_unregister(&data->kobj);
+
+ kobject_put(&data->kobj);
+
+ /* we need to make sure that the underlying kobj is actually
+ * not referenced anymore by anybody before we proceed with
+ * unloading.
+ */
+ dprintk("waiting for dropping of refcount\n");
+ wait_for_completion(&data->kobj_unregister);
+ dprintk("wait complete\n");
+
+ if (cpufreq_driver->exit)
+ cpufreq_driver->exit(data);
+
+ kfree(data);
+
+ cpufreq_debug_enable_ratelimit();
+
+ return 0;
+}
+
+
+static void handle_update(void *data)
+{
+ unsigned int cpu = (unsigned int)(long)data;
+ dprintk("handle_update for cpu %u called\n", cpu);
+ cpufreq_update_policy(cpu);
+}
+
+/**
+ * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble.
+ * @cpu: cpu number
+ * @old_freq: CPU frequency the kernel thinks the CPU runs at
+ * @new_freq: CPU frequency the CPU actually runs at
+ *
+ * We adjust to current frequency first, and need to clean up later. So either call
+ * to cpufreq_update_policy() or schedule handle_update()).
+ */
+static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, unsigned int new_freq)
+{
+ struct cpufreq_freqs freqs;
+
+ printk(KERN_WARNING "Warning: CPU frequency out of sync: cpufreq and timing "
+ "core thinks of %u, is %u kHz.\n", old_freq, new_freq);
+
+ freqs.cpu = cpu;
+ freqs.old = old_freq;
+ freqs.new = new_freq;
+ cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+ cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+}
+
+
+/**
+ * cpufreq_get - get the current CPU frequency (in kHz)
+ * @cpu: CPU number
+ *
+ * Get the CPU current (static) CPU frequency
+ */
+unsigned int cpufreq_get(unsigned int cpu)
+{
+ struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+ unsigned int ret = 0;
+
+ if (!policy)
+ return 0;
+
+ if (!cpufreq_driver->get)
+ goto out;
+
+ down(&policy->lock);
+
+ ret = cpufreq_driver->get(cpu);
+
+ if (ret && policy->cur && !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS))
+ {
+ /* verify no discrepancy between actual and saved value exists */
+ if (unlikely(ret != policy->cur)) {
+ cpufreq_out_of_sync(cpu, policy->cur, ret);
+ schedule_work(&policy->update);
+ }
+ }
+
+ up(&policy->lock);
+
+ out:
+ cpufreq_cpu_put(policy);
+
+ return (ret);
+}
+EXPORT_SYMBOL(cpufreq_get);
+
+
+/**
+ * cpufreq_resume - restore proper CPU frequency handling after resume
+ *
+ * 1.) resume CPUfreq hardware support (cpufreq_driver->resume())
+ * 2.) if ->target and !CPUFREQ_CONST_LOOPS: verify we're in sync
+ * 3.) schedule call cpufreq_update_policy() ASAP as interrupts are restored.
+ */
+static int cpufreq_resume(struct sys_device * sysdev)
+{
+ int cpu = sysdev->id;
+ unsigned int ret = 0;
+ struct cpufreq_policy *cpu_policy;
+
+ dprintk("resuming cpu %u\n", cpu);
+
+ if (!cpu_online(cpu))
+ return 0;
+
+ /* we may be lax here as interrupts are off. Nonetheless
+ * we need to grab the correct cpu policy, as to check
+ * whether we really run on this CPU.
+ */
+
+ cpu_policy = cpufreq_cpu_get(cpu);
+ if (!cpu_policy)
+ return -EINVAL;
+
+ /* only handle each CPU group once */
+ if (unlikely(cpu_policy->cpu != cpu)) {
+ cpufreq_cpu_put(cpu_policy);
+ return 0;
+ }
+
+ if (cpufreq_driver->resume) {
+ ret = cpufreq_driver->resume(cpu_policy);
+ if (ret) {
+ printk(KERN_ERR "cpufreq: resume failed in ->resume "
+ "step on CPU %u\n", cpu_policy->cpu);
+ cpufreq_cpu_put(cpu_policy);
+ return ret;
+ }
+ }
+
+ if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
+ unsigned int cur_freq = 0;
+
+ if (cpufreq_driver->get)
+ cur_freq = cpufreq_driver->get(cpu_policy->cpu);
+
+ if (!cur_freq || !cpu_policy->cur) {
+ printk(KERN_ERR "cpufreq: resume failed to assert current frequency is what timing core thinks it is.\n");
+ goto out;
+ }
+
+ if (unlikely(cur_freq != cpu_policy->cur)) {
+ struct cpufreq_freqs freqs;
+
+ printk(KERN_WARNING "Warning: CPU frequency is %u, "
+ "cpufreq assumed %u kHz.\n", cur_freq, cpu_policy->cur);
+
+ freqs.cpu = cpu;
+ freqs.old = cpu_policy->cur;
+ freqs.new = cur_freq;
+
+ notifier_call_chain(&cpufreq_transition_notifier_list, CPUFREQ_RESUMECHANGE, &freqs);
+ adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs);
+
+ cpu_policy->cur = cur_freq;
+ }
+ }
+
+out:
+ schedule_work(&cpu_policy->update);
+ cpufreq_cpu_put(cpu_policy);
+ return ret;
+}
+
+static struct sysdev_driver cpufreq_sysdev_driver = {
+ .add = cpufreq_add_dev,
+ .remove = cpufreq_remove_dev,
+ .resume = cpufreq_resume,
+};
+
+
+/*********************************************************************
+ * NOTIFIER LISTS INTERFACE *
+ *********************************************************************/
+
+/**
+ * cpufreq_register_notifier - register a driver with cpufreq
+ * @nb: notifier function to register
+ * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
+ *
+ * Add a driver to one of two lists: either a list of drivers that
+ * are notified about clock rate changes (once before and once after
+ * the transition), or a list of drivers that are notified about
+ * changes in cpufreq policy.
+ *
+ * This function may sleep, and has the same return conditions as
+ * notifier_chain_register.
+ */
+int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
+{
+ int ret;
+
+ down_write(&cpufreq_notifier_rwsem);
+ switch (list) {
+ case CPUFREQ_TRANSITION_NOTIFIER:
+ ret = notifier_chain_register(&cpufreq_transition_notifier_list, nb);
+ break;
+ case CPUFREQ_POLICY_NOTIFIER:
+ ret = notifier_chain_register(&cpufreq_policy_notifier_list, nb);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+ up_write(&cpufreq_notifier_rwsem);
+
+ return ret;
+}
+EXPORT_SYMBOL(cpufreq_register_notifier);
+
+
+/**
+ * cpufreq_unregister_notifier - unregister a driver with cpufreq
+ * @nb: notifier block to be unregistered
+ * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
+ *
+ * Remove a driver from the CPU frequency notifier list.
+ *
+ * This function may sleep, and has the same return conditions as
+ * notifier_chain_unregister.
+ */
+int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
+{
+ int ret;
+
+ down_write(&cpufreq_notifier_rwsem);
+ switch (list) {
+ case CPUFREQ_TRANSITION_NOTIFIER:
+ ret = notifier_chain_unregister(&cpufreq_transition_notifier_list, nb);
+ break;
+ case CPUFREQ_POLICY_NOTIFIER:
+ ret = notifier_chain_unregister(&cpufreq_policy_notifier_list, nb);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+ up_write(&cpufreq_notifier_rwsem);
+
+ return ret;
+}
+EXPORT_SYMBOL(cpufreq_unregister_notifier);
+
+
+/*********************************************************************
+ * GOVERNORS *
+ *********************************************************************/
+
+
+int __cpufreq_driver_target(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int relation)
+{
+ int retval = -EINVAL;
+ lock_cpu_hotplug();
+ dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu,
+ target_freq, relation);
+ if (cpu_online(policy->cpu) && cpufreq_driver->target)
+ retval = cpufreq_driver->target(policy, target_freq, relation);
+ unlock_cpu_hotplug();
+ return retval;
+}
+EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
+
+
+int cpufreq_driver_target(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int relation)
+{
+ unsigned int ret;
+
+ policy = cpufreq_cpu_get(policy->cpu);
+ if (!policy)
+ return -EINVAL;
+
+ down(&policy->lock);
+
+ ret = __cpufreq_driver_target(policy, target_freq, relation);
+
+ up(&policy->lock);
+
+ cpufreq_cpu_put(policy);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(cpufreq_driver_target);
+
+
+static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event)
+{
+ int ret = -EINVAL;
+
+ if (!try_module_get(policy->governor->owner))
+ return -EINVAL;
+
+ dprintk("__cpufreq_governor for CPU %u, event %u\n", policy->cpu, event);
+ ret = policy->governor->governor(policy, event);
+
+ /* we keep one module reference alive for each CPU governed by this CPU */
+ if ((event != CPUFREQ_GOV_START) || ret)
+ module_put(policy->governor->owner);
+ if ((event == CPUFREQ_GOV_STOP) && !ret)
+ module_put(policy->governor->owner);
+
+ return ret;
+}
+
+
+int cpufreq_governor(unsigned int cpu, unsigned int event)
+{
+ int ret = 0;
+ struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+
+ if (!policy)
+ return -EINVAL;
+
+ down(&policy->lock);
+ ret = __cpufreq_governor(policy, event);
+ up(&policy->lock);
+
+ cpufreq_cpu_put(policy);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(cpufreq_governor);
+
+
+int cpufreq_register_governor(struct cpufreq_governor *governor)
+{
+ struct cpufreq_governor *t;
+
+ if (!governor)
+ return -EINVAL;
+
+ down(&cpufreq_governor_sem);
+
+ list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
+ if (!strnicmp(governor->name,t->name,CPUFREQ_NAME_LEN)) {
+ up(&cpufreq_governor_sem);
+ return -EBUSY;
+ }
+ }
+ list_add(&governor->governor_list, &cpufreq_governor_list);
+
+ up(&cpufreq_governor_sem);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(cpufreq_register_governor);
+
+
+void cpufreq_unregister_governor(struct cpufreq_governor *governor)
+{
+ if (!governor)
+ return;
+
+ down(&cpufreq_governor_sem);
+ list_del(&governor->governor_list);
+ up(&cpufreq_governor_sem);
+ return;
+}
+EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
+
+
+
+/*********************************************************************
+ * POLICY INTERFACE *
+ *********************************************************************/
+
+/**
+ * cpufreq_get_policy - get the current cpufreq_policy
+ * @policy: struct cpufreq_policy into which the current cpufreq_policy is written
+ *
+ * Reads the current cpufreq policy.
+ */
+int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
+{
+ struct cpufreq_policy *cpu_policy;
+ if (!policy)
+ return -EINVAL;
+
+ cpu_policy = cpufreq_cpu_get(cpu);
+ if (!cpu_policy)
+ return -EINVAL;
+
+ down(&cpu_policy->lock);
+ memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy));
+ up(&cpu_policy->lock);
+
+ cpufreq_cpu_put(cpu_policy);
+
+ return 0;
+}
+EXPORT_SYMBOL(cpufreq_get_policy);
+
+
+static int __cpufreq_set_policy(struct cpufreq_policy *data, struct cpufreq_policy *policy)
+{
+ int ret = 0;
+
+ cpufreq_debug_disable_ratelimit();
+ dprintk("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu,
+ policy->min, policy->max);
+
+ memcpy(&policy->cpuinfo,
+ &data->cpuinfo,
+ sizeof(struct cpufreq_cpuinfo));
+
+ /* verify the cpu speed can be set within this limit */
+ ret = cpufreq_driver->verify(policy);
+ if (ret)
+ goto error_out;
+
+ down_read(&cpufreq_notifier_rwsem);
+
+ /* adjust if necessary - all reasons */
+ notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_ADJUST,
+ policy);
+
+ /* adjust if necessary - hardware incompatibility*/
+ notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_INCOMPATIBLE,
+ policy);
+
+ /* verify the cpu speed can be set within this limit,
+ which might be different to the first one */
+ ret = cpufreq_driver->verify(policy);
+ if (ret) {
+ up_read(&cpufreq_notifier_rwsem);
+ goto error_out;
+ }
+
+ /* notification of the new policy */
+ notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_NOTIFY,
+ policy);
+
+ up_read(&cpufreq_notifier_rwsem);
+
+ data->min = policy->min;
+ data->max = policy->max;
+
+ dprintk("new min and max freqs are %u - %u kHz\n", data->min, data->max);
+
+ if (cpufreq_driver->setpolicy) {
+ data->policy = policy->policy;
+ dprintk("setting range\n");
+ ret = cpufreq_driver->setpolicy(policy);
+ } else {
+ if (policy->governor != data->governor) {
+ /* save old, working values */
+ struct cpufreq_governor *old_gov = data->governor;
+
+ dprintk("governor switch\n");
+
+ /* end old governor */
+ if (data->governor)
+ __cpufreq_governor(data, CPUFREQ_GOV_STOP);
+
+ /* start new governor */
+ data->governor = policy->governor;
+ if (__cpufreq_governor(data, CPUFREQ_GOV_START)) {
+ /* new governor failed, so re-start old one */
+ dprintk("starting governor %s failed\n", data->governor->name);
+ if (old_gov) {
+ data->governor = old_gov;
+ __cpufreq_governor(data, CPUFREQ_GOV_START);
+ }
+ ret = -EINVAL;
+ goto error_out;
+ }
+ /* might be a policy change, too, so fall through */
+ }
+ dprintk("governor: change or update limits\n");
+ __cpufreq_governor(data, CPUFREQ_GOV_LIMITS);
+ }
+
+ error_out:
+ cpufreq_debug_enable_ratelimit();
+ return ret;
+}
+
+/**
+ * cpufreq_set_policy - set a new CPUFreq policy
+ * @policy: policy to be set.
+ *
+ * Sets a new CPU frequency and voltage scaling policy.
+ */
+int cpufreq_set_policy(struct cpufreq_policy *policy)
+{
+ int ret = 0;
+ struct cpufreq_policy *data;
+
+ if (!policy)
+ return -EINVAL;
+
+ data = cpufreq_cpu_get(policy->cpu);
+ if (!data)
+ return -EINVAL;
+
+ /* lock this CPU */
+ down(&data->lock);
+
+ ret = __cpufreq_set_policy(data, policy);
+ data->user_policy.min = data->min;
+ data->user_policy.max = data->max;
+ data->user_policy.policy = data->policy;
+ data->user_policy.governor = data->governor;
+
+ up(&data->lock);
+ cpufreq_cpu_put(data);
+
+ return ret;
+}
+EXPORT_SYMBOL(cpufreq_set_policy);
+
+
+/**
+ * cpufreq_update_policy - re-evaluate an existing cpufreq policy
+ * @cpu: CPU which shall be re-evaluated
+ *
+ * Usefull for policy notifiers which have different necessities
+ * at different times.
+ */
+int cpufreq_update_policy(unsigned int cpu)
+{
+ struct cpufreq_policy *data = cpufreq_cpu_get(cpu);
+ struct cpufreq_policy policy;
+ int ret = 0;
+
+ if (!data)
+ return -ENODEV;
+
+ down(&data->lock);
+
+ dprintk("updating policy for CPU %u\n", cpu);
+ memcpy(&policy,
+ data,
+ sizeof(struct cpufreq_policy));
+ policy.min = data->user_policy.min;
+ policy.max = data->user_policy.max;
+ policy.policy = data->user_policy.policy;
+ policy.governor = data->user_policy.governor;
+
+ ret = __cpufreq_set_policy(data, &policy);
+
+ up(&data->lock);
+
+ cpufreq_cpu_put(data);
+ return ret;
+}
+EXPORT_SYMBOL(cpufreq_update_policy);
+
+
+/*********************************************************************
+ * REGISTER / UNREGISTER CPUFREQ DRIVER *
+ *********************************************************************/
+
+/**
+ * cpufreq_register_driver - register a CPU Frequency driver
+ * @driver_data: A struct cpufreq_driver containing the values#
+ * submitted by the CPU Frequency driver.
+ *
+ * Registers a CPU Frequency driver to this core code. This code
+ * returns zero on success, -EBUSY when another driver got here first
+ * (and isn't unregistered in the meantime).
+ *
+ */
+int cpufreq_register_driver(struct cpufreq_driver *driver_data)
+{
+ unsigned long flags;
+ int ret;
+
+ if (!driver_data || !driver_data->verify || !driver_data->init ||
+ ((!driver_data->setpolicy) && (!driver_data->target)))
+ return -EINVAL;
+
+ dprintk("trying to register driver %s\n", driver_data->name);
+
+ if (driver_data->setpolicy)
+ driver_data->flags |= CPUFREQ_CONST_LOOPS;
+
+ spin_lock_irqsave(&cpufreq_driver_lock, flags);
+ if (cpufreq_driver) {
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ return -EBUSY;
+ }
+ cpufreq_driver = driver_data;
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+ ret = sysdev_driver_register(&cpu_sysdev_class,&cpufreq_sysdev_driver);
+
+ if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) {
+ int i;
+ ret = -ENODEV;
+
+ /* check for at least one working CPU */
+ for (i=0; i<NR_CPUS; i++)
+ if (cpufreq_cpu_data[i])
+ ret = 0;
+
+ /* if all ->init() calls failed, unregister */
+ if (ret) {
+ dprintk("no CPU initialized for driver %s\n", driver_data->name);
+ sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver);
+
+ spin_lock_irqsave(&cpufreq_driver_lock, flags);
+ cpufreq_driver = NULL;
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ }
+ }
+
+ if (!ret) {
+ dprintk("driver %s up and running\n", driver_data->name);
+ cpufreq_debug_enable_ratelimit();
+ }
+
+ return (ret);
+}
+EXPORT_SYMBOL_GPL(cpufreq_register_driver);
+
+
+/**
+ * cpufreq_unregister_driver - unregister the current CPUFreq driver
+ *
+ * Unregister the current CPUFreq driver. Only call this if you have
+ * the right to do so, i.e. if you have succeeded in initialising before!
+ * Returns zero if successful, and -EINVAL if the cpufreq_driver is
+ * currently not initialised.
+ */
+int cpufreq_unregister_driver(struct cpufreq_driver *driver)
+{
+ unsigned long flags;
+
+ cpufreq_debug_disable_ratelimit();
+
+ if (!cpufreq_driver || (driver != cpufreq_driver)) {
+ cpufreq_debug_enable_ratelimit();
+ return -EINVAL;
+ }
+
+ dprintk("unregistering driver %s\n", driver->name);
+
+ sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver);
+
+ spin_lock_irqsave(&cpufreq_driver_lock, flags);
+ cpufreq_driver = NULL;
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);