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/*
* linux/arch/arm/mach-integrator/cpu.c
*
* Copyright (C) 2001-2002 Deep Blue Solutions Ltd.
*
* 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.
*
* CPU support functions
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/cpufreq.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/io.h>
#include <mach/hardware.h>
#include <asm/mach-types.h>
#include <asm/hardware/icst525.h>
static struct cpufreq_driver integrator_driver;
#define CM_ID (IO_ADDRESS(INTEGRATOR_HDR_BASE)+INTEGRATOR_HDR_ID_OFFSET)
#define CM_OSC (IO_ADDRESS(INTEGRATOR_HDR_BASE)+INTEGRATOR_HDR_OSC_OFFSET)
#define CM_STAT (IO_ADDRESS(INTEGRATOR_HDR_BASE)+INTEGRATOR_HDR_STAT_OFFSET)
#define CM_LOCK (IO_ADDRESS(INTEGRATOR_HDR_BASE)+INTEGRATOR_HDR_LOCK_OFFSET)
static const struct icst525_params lclk_params = {
.ref = 24000,
.vco_max = 320000,
.vd_min = 8,
.vd_max = 132,
.rd_min = 24,
.rd_max = 24,
};
static const struct icst525_params cclk_params = {
.ref = 24000,
.vco_max = 320000,
.vd_min = 12,
.vd_max = 160,
.rd_min = 24,
.rd_max = 24,
};
/*
* Validate the speed policy.
*/
static int integrator_verify_policy(struct cpufreq_policy *policy)
{
struct icst525_vco vco;
cpufreq_verify_within_limits(policy,
policy->cpuinfo.min_freq,
policy->cpuinfo.max_freq);
vco = icst525_khz_to_vco(&cclk_params, policy->max);
policy->max = icst525_khz(&cclk_params, vco);
vco = icst525_khz_to_vco(&cclk_params, policy->min);
policy->min = icst525_khz(&cclk_params, vco);
cpufreq_verify_within_limits(policy,
policy->cpuinfo.min_freq,
policy->cpuinfo.max_freq);
return 0;
}
static int integrator_set_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
{
cpumask_t cpus_allowed;
int cpu = policy->cpu;
struct icst525_vco vco;
struct cpufreq_freqs freqs;
u_int cm_osc;
/*
* Save this threads cpus_allowed mask.
*/
cpus_allowed = current->cpus_allowed;
/*
* Bind to the specified CPU. When this call returns,
* we should be running on the right CPU.
*/
set_cpus_allowed(current, cpumask_of_cpu(cpu));
BUG_ON(cpu != smp_processor_id());
/* get current setting */
cm_osc = __raw_readl(CM_OSC);
if (machine_is_integrator()) {
vco.s = (cm_osc >> 8) & 7;
} else if (machine_is_cintegrator()) {
vco.s = 1;
}
vco.v = cm_osc & 255;
vco.r = 22;
freqs.old = icst525_khz(&cclk_params, vco);
/* icst525_khz_to_vco rounds down -- so we need the next
* larger freq in case of CPUFREQ_RELATION_L.
*/
if (relation == CPUFREQ_RELATION_L)
target_freq += 999;
if (target_freq > policy->max)
target_freq = policy->max;
vco = icst525_khz_to_vco(&cclk_params, target_freq);
freqs.new = icst525_khz(&cclk_params, vco);
freqs.cpu = policy->cpu;
if (freqs.old == freqs.new) {
set_cpus_allowed(current, cpus_allowed);
return 0;
}
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
cm_osc = __raw_readl(CM_OSC);
if (machine_is_integrator()) {
cm_osc &= 0xfffff800;
cm_osc |= vco.s << 8;
} else if (machine_is_cintegrator()) {
cm_osc &= 0xffffff00;
}
cm_osc |= vco.v;
__raw_writel(0xa05f, CM_LOCK);
__raw_writel(cm_osc, CM_OSC);
__raw_writel(0, CM_LOCK);
/*
* Restore the CPUs allowed mask.
*/
set_cpus_allowed(current, cpus_allowed);
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
return 0;
}
static unsigned int integrator_get(unsigned int cpu)
{
cpumask_t cpus_allowed;
unsigned int current_freq;
u_int cm_osc;
struct icst525_vco vco;
cpus_allowed = current->cpus_allowed;
set_cpus_allowed(current, cpumask_of_cpu(cpu));
BUG_ON(cpu != smp_processor_id());
/* detect memory etc. */
cm_osc = __raw_readl(CM_OSC);
if (machine_is_integrator()) {
vco.s = (cm_osc >> 8) & 7;
} else if (machine_is_cintegrator()) {
vco.s = 1;
}
vco.v = cm_osc & 255;
vco.r = 22;
current_freq = icst525_khz(&cclk_params, vco); /* current freq */
set_cpus_allowed(current, cpus_allowed);
return current_freq;
}
static int integrator_cpufreq_init(struct cpufreq_policy *policy)
{
/* set default policy and cpuinfo */
policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
policy->cpuinfo.max_freq = 160000;
policy->cpuinfo.min_freq = 12000;
policy->cpuinfo.transition_latency = 1000000; /* 1 ms, assumed */
policy->cur = policy->min = policy->max = integrator_get(policy->cpu);
return 0;
}
static struct cpufreq_driver integrator_driver = {
.verify = integrator_verify_policy,
.target = integrator_set_target,
.get = integrator_get,
.init = integrator_cpufreq_init,
.name = "integrator",
};
static int __init integrator_cpu_init(void)
{
return cpufreq_register_driver(&integrator_driver);
}
static void __exit integrator_cpu_exit(void)
{
cpufreq_unregister_driver(&integrator_driver);
}
MODULE_AUTHOR ("Russell M. King");
MODULE_DESCRIPTION ("cpufreq driver for ARM Integrator CPUs");
MODULE_LICENSE ("GPL");
module_init(integrator_cpu_init);
module_exit(integrator_cpu_exit);
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