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/*
* bcu.c, Bus Control Unit routines for the NEC VR4100 series.
*
* Copyright (C) 2002 MontaVista Software Inc.
* Author: Yoichi Yuasa <source@mvista.com>
* Copyright (C) 2003-2005 Yoichi Yuasa <yuasa@linux-mips.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Changes:
* MontaVista Software Inc. <source@mvista.com>
* - New creation, NEC VR4122 and VR4131 are supported.
* - Added support for NEC VR4111 and VR4121.
*
* Yoichi Yuasa <yuasa@linux-mips.org>
* - Added support for NEC VR4133.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/smp.h>
#include <linux/types.h>
#include <asm/cpu.h>
#include <asm/io.h>
#define CLKSPEEDREG_TYPE1 (void __iomem *)KSEG1ADDR(0x0b000014)
#define CLKSPEEDREG_TYPE2 (void __iomem *)KSEG1ADDR(0x0f000014)
#define CLKSP(x) ((x) & 0x001f)
#define CLKSP_VR4133(x) ((x) & 0x0007)
#define DIV2B 0x8000
#define DIV3B 0x4000
#define DIV4B 0x2000
#define DIVT(x) (((x) & 0xf000) >> 12)
#define DIVVT(x) (((x) & 0x0f00) >> 8)
#define TDIVMODE(x) (2 << (((x) & 0x1000) >> 12))
#define VTDIVMODE(x) (((x) & 0x0700) >> 8)
static unsigned long vr41xx_vtclock;
static unsigned long vr41xx_tclock;
unsigned long vr41xx_get_vtclock_frequency(void)
{
return vr41xx_vtclock;
}
EXPORT_SYMBOL_GPL(vr41xx_get_vtclock_frequency);
unsigned long vr41xx_get_tclock_frequency(void)
{
return vr41xx_tclock;
}
EXPORT_SYMBOL_GPL(vr41xx_get_tclock_frequency);
static inline uint16_t read_clkspeed(void)
{
switch (current_cpu_type()) {
case CPU_VR4111:
case CPU_VR4121: return readw(CLKSPEEDREG_TYPE1);
case CPU_VR4122:
case CPU_VR4131:
case CPU_VR4133: return readw(CLKSPEEDREG_TYPE2);
default:
printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
break;
}
return 0;
}
static inline unsigned long calculate_pclock(uint16_t clkspeed)
{
unsigned long pclock = 0;
switch (current_cpu_type()) {
case CPU_VR4111:
case CPU_VR4121:
pclock = 18432000 * 64;
pclock /= CLKSP(clkspeed);
break;
case CPU_VR4122:
pclock = 18432000 * 98;
pclock /= CLKSP(clkspeed);
break;
case CPU_VR4131:
pclock = 18432000 * 108;
pclock /= CLKSP(clkspeed);
break;
case CPU_VR4133:
switch (CLKSP_VR4133(clkspeed)) {
case 0:
pclock = 133000000;
break;
case 1:
pclock = 149000000;
break;
case 2:
pclock = 165900000;
break;
case 3:
pclock = 199100000;
break;
case 4:
pclock = 265900000;
break;
default:
printk(KERN_INFO "Unknown PClock speed for NEC VR4133\n");
break;
}
break;
default:
printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
break;
}
printk(KERN_INFO "PClock: %ldHz\n", pclock);
return pclock;
}
static inline unsigned long calculate_vtclock(uint16_t clkspeed, unsigned long pclock)
{
unsigned long vtclock = 0;
switch (current_cpu_type()) {
case CPU_VR4111:
/* The NEC VR4111 doesn't have the VTClock. */
break;
case CPU_VR4121:
vtclock = pclock;
/* DIVVT == 9 Divide by 1.5 . VTClock = (PClock * 6) / 9 */
if (DIVVT(clkspeed) == 9)
vtclock = pclock * 6;
/* DIVVT == 10 Divide by 2.5 . VTClock = (PClock * 4) / 10 */
else if (DIVVT(clkspeed) == 10)
vtclock = pclock * 4;
vtclock /= DIVVT(clkspeed);
printk(KERN_INFO "VTClock: %ldHz\n", vtclock);
break;
case CPU_VR4122:
if(VTDIVMODE(clkspeed) == 7)
vtclock = pclock / 1;
else if(VTDIVMODE(clkspeed) == 1)
vtclock = pclock / 2;
else
vtclock = pclock / VTDIVMODE(clkspeed);
printk(KERN_INFO "VTClock: %ldHz\n", vtclock);
break;
case CPU_VR4131:
case CPU_VR4133:
vtclock = pclock / VTDIVMODE(clkspeed);
printk(KERN_INFO "VTClock: %ldHz\n", vtclock);
break;
default:
printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
break;
}
return vtclock;
}
static inline unsigned long calculate_tclock(uint16_t clkspeed, unsigned long pclock,
unsigned long vtclock)
{
unsigned long tclock = 0;
switch (current_cpu_type()) {
case CPU_VR4111:
if (!(clkspeed & DIV2B))
tclock = pclock / 2;
else if (!(clkspeed & DIV3B))
tclock = pclock / 3;
else if (!(clkspeed & DIV4B))
tclock = pclock / 4;
break;
case CPU_VR4121:
tclock = pclock / DIVT(clkspeed);
break;
case CPU_VR4122:
case CPU_VR4131:
case CPU_VR4133:
tclock = vtclock / TDIVMODE(clkspeed);
break;
default:
printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
break;
}
printk(KERN_INFO "TClock: %ldHz\n", tclock);
return tclock;
}
void vr41xx_calculate_clock_frequency(void)
{
unsigned long pclock;
uint16_t clkspeed;
clkspeed = read_clkspeed();
pclock = calculate_pclock(clkspeed);
vr41xx_vtclock = calculate_vtclock(clkspeed, pclock);
vr41xx_tclock = calculate_tclock(clkspeed, pclock, vr41xx_vtclock);
}
EXPORT_SYMBOL_GPL(vr41xx_calculate_clock_frequency);
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