Linux-2.6.12-rc2v2.6.12-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!

1 files changed, 1428 insertions, 0 deletions

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
new file mode 100644
index 000000000000..b30001f31610
--- /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);