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/*
* linux/arch/arm/mach-integrator/cpu.c
*
* Copyright (C) 2001 Deep Blue Solutions Ltd.
*
* $Id: cpu.c,v 1.2 2001/09/22 12:11:17 rmk Exp $
*
* 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/config.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/cpufreq.h>
#include <linux/init.h>
#include <asm/hardware.h>
#include <asm/io.h>
#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)
struct vco {
unsigned char vdw;
unsigned char od;
};
/*
* Divisors for each OD setting.
*/
static unsigned char cc_divisor[8] = { 10, 2, 8, 4, 5, 7, 9, 6 };
static unsigned int vco_to_freq(struct vco vco, int factor)
{
return 2000 * (vco.vdw + 8) / cc_divisor[vco.od] / factor;
}
#ifdef CONFIG_CPU_FREQ
/*
* Divisor indexes for in ascending divisor order
*/
static unsigned char s2od[] = { 1, 3, 4, 7, 5, 2, 6, 0 };
static struct vco freq_to_vco(unsigned int freq_khz, int factor)
{
struct vco vco = {0, 0};
unsigned int i, f;
freq_khz *= factor;
for (i = 0; i < 8; i++) {
f = freq_khz * cc_divisor[s2od[i]];
/* f must be between 10MHz and 320MHz */
if (f > 10000 && f <= 320000)
break;
}
vco.od = s2od[i];
vco.vdw = f / 2000 - 8;
return vco;
}
/*
* Validate the speed in khz. If it is outside our
* range, then return the lowest.
*/
unsigned int integrator_validatespeed(unsigned int freq_khz)
{
struct vco vco;
if (freq_khz < 12000)
freq_khz = 12000;
if (freq_khz > 160000)
freq_khz = 160000;
vco = freq_to_vco(freq_khz, 1);
if (vco.vdw < 4 || vco.vdw > 152)
return -EINVAL;
return vco_to_freq(vco, 1);
}
void integrator_setspeed(unsigned int freq_khz)
{
struct vco vco = freq_to_vco(freq_khz, 1);
u_int cm_osc;
cm_osc = __raw_readl(CM_OSC);
cm_osc &= 0xfffff800;
cm_osc |= vco.vdw | vco.od << 8;
__raw_writel(0xa05f, CM_LOCK);
__raw_writel(cm_osc, CM_OSC);
__raw_writel(0, CM_LOCK);
}
#endif
static int __init cpu_init(void)
{
u_int cm_osc, cm_stat, cpu_freq_khz, mem_freq_khz;
struct vco vco;
cm_osc = __raw_readl(CM_OSC);
vco.od = (cm_osc >> 20) & 7;
vco.vdw = (cm_osc >> 12) & 255;
mem_freq_khz = vco_to_freq(vco, 2);
printk(KERN_INFO "Memory clock = %d.%03d MHz\n",
mem_freq_khz / 1000, mem_freq_khz % 1000);
vco.od = (cm_osc >> 8) & 7;
vco.vdw = cm_osc & 255;
cpu_freq_khz = vco_to_freq(vco, 1);
#ifdef CONFIG_CPU_FREQ
cpufreq_init(cpu_freq_khz);
cpufreq_setfunctions(integrator_validatespeed, integrator_setspeed);
#endif
cm_stat = __raw_readl(CM_STAT);
printk("Module id: %d\n", cm_stat & 255);
return 0;
}
__initcall(cpu_init);
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