/*
* 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/sched.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <asm/mach-types.h>
#include <asm/hardware/icst.h>
static void __iomem *cm_base;
/* The cpufreq driver only use the OSC register */
#define INTEGRATOR_HDR_OSC_OFFSET 0x08
#define INTEGRATOR_HDR_LOCK_OFFSET 0x14
static struct cpufreq_driver integrator_driver;
static const struct icst_params lclk_params = {
.ref = 24000000,
.vco_max = ICST525_VCO_MAX_5V,
.vco_min = ICST525_VCO_MIN,
.vd_min = 8,
.vd_max = 132,
.rd_min = 24,
.rd_max = 24,
.s2div = icst525_s2div,
.idx2s = icst525_idx2s,
};
static const struct icst_params cclk_params = {
.ref = 24000000,
.vco_max = ICST525_VCO_MAX_5V,
.vco_min = ICST525_VCO_MIN,
.vd_min = 12,
.vd_max = 160,
.rd_min = 24,
.rd_max = 24,
.s2div = icst525_s2div,
.idx2s = icst525_idx2s,
};
/*
* Validate the speed policy.
*/
static int integrator_verify_policy(struct cpufreq_policy *policy)
{
struct icst_vco vco;
cpufreq_verify_within_cpu_limits(policy);
vco = icst_hz_to_vco(&cclk_params, policy->max * 1000);
policy->max = icst_hz(&cclk_params, vco) / 1000;
vco = icst_hz_to_vco(&cclk_params, policy->min * 1000);
policy->min = icst_hz(&cclk_params, vco) / 1000;
cpufreq_verify_within_cpu_limits(policy);
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 icst_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_base + INTEGRATOR_HDR_OSC_OFFSET);
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 = icst_hz(&cclk_params, vco) / 1000;
/* icst_hz_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 = icst_hz_to_vco(&cclk_params, target_freq * 1000);
freqs.new = icst_hz(&cclk_params, vco) / 1000;
if (freqs.old == freqs.new) {
set_cpus_allowed(current, cpus_allowed);
return 0;
}
cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
cm_osc = __raw_readl(cm_base + INTEGRATOR_HDR_OSC_OFFSET);
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_base + INTEGRATOR_HDR_LOCK_OFFSET);
__raw_writel(cm_osc, cm_base + INTEGRATOR_HDR_OSC_OFFSET);
__raw_writel(0, cm_base + INTEGRATOR_HDR_LOCK_OFFSET);
/*
* Restore the CPUs allowed mask.
*/
set_cpus_allowed(current, cpus_allowed);
cpufreq_notify_transition(policy, &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 icst_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_base + INTEGRATOR_HDR_OSC_OFFSET);
if (machine_is_integrator()) {
vco.s = (cm_osc >> 8) & 7;
} else {
vco.s = 1;
}
vco.v = cm_osc & 255;
vco.r = 22;
current_freq = icst_hz(&cclk_params, vco) / 1000; /* 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->max = policy->cpuinfo.max_freq = 160000;
policy->min = policy->cpuinfo.min_freq = 12000;
policy->cpuinfo.transition_latency = 1000000; /* 1 ms, assumed */
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_cpufreq_probe(struct platform_device *pdev)
{
struct resource *res;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -ENODEV;
cm_base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
if (!cm_base)
return -ENODEV;
return cpufreq_register_driver(&integrator_driver);
}
static void __exit integrator_cpufreq_remove(struct platform_device *pdev)
{
cpufreq_unregister_driver(&integrator_driver);
}
static const struct of_device_id integrator_cpufreq_match[] = {
{ .compatible = "arm,core-module-integrator"},
{ },
};
static struct platform_driver integrator_cpufreq_driver = {
.driver = {
.name = "integrator-cpufreq",
.owner = THIS_MODULE,
.of_match_table = integrator_cpufreq_match,
},
.remove = __exit_p(integrator_cpufreq_remove),
};
module_platform_driver_probe(integrator_cpufreq_driver,
integrator_cpufreq_probe);
MODULE_AUTHOR ("Russell M. King");
MODULE_DESCRIPTION ("cpufreq driver for ARM Integrator CPUs");
MODULE_LICENSE ("GPL");
