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#include <linux/types.h>

#include <linux/errno.h>

#include <linux/kernel.h>

#include <linux/delay.h>

#include <linux/slab.h>

#include <linux/init.h>

#include <linux/wait.h>

#include <linux/cpufreq.h>

#include <asm/prom.h>

#include "windfarm.h"

#define VERSION "0.3"

static int clamped;

static struct wf_control *clamp_control;

static int clamp_notifier_call(struct notifier_block *self,

                               unsigned long event, void *data)

{

        struct cpufreq_policy *p = data;

        unsigned long max_freq;

        if (event != CPUFREQ_ADJUST)

                return 0;

        max_freq = clamped ? (p->cpuinfo.min_freq) : (p->cpuinfo.max_freq);

        cpufreq_verify_within_limits(p, 0, max_freq);

        return 0;

}

static struct notifier_block clamp_notifier = {

        .notifier_call = clamp_notifier_call,

};

static int clamp_set(struct wf_control *ct, s32 value)

{

        if (value)

                printk(KERN_INFO "windfarm: Clamping CPU frequency to "

                       "minimum !\n");

        else

                printk(KERN_INFO "windfarm: CPU frequency unclamped !\n");

        clamped = value;

        cpufreq_update_policy(0);

        return 0;

}

static int clamp_get(struct wf_control *ct, s32 *value)

{

        *value = clamped;

        return 0;

}

static s32 clamp_min(struct wf_control *ct)

{

        return 0;

}

static s32 clamp_max(struct wf_control *ct)

{

        return 1;

}

static struct wf_control_ops clamp_ops = {

        .set_value      = clamp_set,

        .get_value      = clamp_get,

        .get_min        = clamp_min,

        .get_max        = clamp_max,

        .owner          = THIS_MODULE,

};

static int __init wf_cpufreq_clamp_init(void)

{

        struct wf_control *clamp;

        /* Don't register on old machines that use therm_pm72 for now */

        if (machine_is_compatible("PowerMac7,2") ||

            machine_is_compatible("PowerMac7,3") ||

            machine_is_compatible("RackMac3,1"))

                return -ENODEV;

        clamp = kmalloc(sizeof(struct wf_control), GFP_KERNEL);

        if (clamp == NULL)

                return -ENOMEM;

        cpufreq_register_notifier(&clamp_notifier, CPUFREQ_POLICY_NOTIFIER);

        clamp->ops = &clamp_ops;

        clamp->name = "cpufreq-clamp";

        if (wf_register_control(clamp))

                goto fail;

        clamp_control = clamp;

        return 0;

 fail:

        kfree(clamp);

        return -ENODEV;

}

static void __exit wf_cpufreq_clamp_exit(void)

{

        if (clamp_control)

                wf_unregister_control(clamp_control);

}

module_init(wf_cpufreq_clamp_init);

module_exit(wf_cpufreq_clamp_exit);

MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");

MODULE_DESCRIPTION("CPU frequency clamp for PowerMacs thermal control");

MODULE_LICENSE("GPL");