linux/arch/arm/mach-gemini/time.c

90 lines
2.4 KiB
C

/*
* Copyright (C) 2001-2006 Storlink, Corp.
* Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
*
* 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.
*/
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <mach/hardware.h>
#include <mach/global_reg.h>
#include <asm/mach/time.h>
/*
* Register definitions for the timers
*/
#define TIMER_COUNT(BASE_ADDR) (BASE_ADDR + 0x00)
#define TIMER_LOAD(BASE_ADDR) (BASE_ADDR + 0x04)
#define TIMER_MATCH1(BASE_ADDR) (BASE_ADDR + 0x08)
#define TIMER_MATCH2(BASE_ADDR) (BASE_ADDR + 0x0C)
#define TIMER_CR(BASE_ADDR) (BASE_ADDR + 0x30)
#define TIMER_1_CR_ENABLE (1 << 0)
#define TIMER_1_CR_CLOCK (1 << 1)
#define TIMER_1_CR_INT (1 << 2)
#define TIMER_2_CR_ENABLE (1 << 3)
#define TIMER_2_CR_CLOCK (1 << 4)
#define TIMER_2_CR_INT (1 << 5)
#define TIMER_3_CR_ENABLE (1 << 6)
#define TIMER_3_CR_CLOCK (1 << 7)
#define TIMER_3_CR_INT (1 << 8)
/*
* IRQ handler for the timer
*/
static irqreturn_t gemini_timer_interrupt(int irq, void *dev_id)
{
timer_tick();
return IRQ_HANDLED;
}
static struct irqaction gemini_timer_irq = {
.name = "Gemini Timer Tick",
.flags = IRQF_DISABLED | IRQF_TIMER,
.handler = gemini_timer_interrupt,
};
/*
* Set up timer interrupt, and return the current time in seconds.
*/
void __init gemini_timer_init(void)
{
unsigned int tick_rate, reg_v;
reg_v = __raw_readl(IO_ADDRESS(GEMINI_GLOBAL_BASE + GLOBAL_STATUS));
tick_rate = REG_TO_AHB_SPEED(reg_v) * 1000000;
printk(KERN_INFO "Bus: %dMHz", tick_rate / 1000000);
tick_rate /= 6; /* APB bus run AHB*(1/6) */
switch(reg_v & CPU_AHB_RATIO_MASK) {
case CPU_AHB_1_1:
printk(KERN_CONT "(1/1)\n");
break;
case CPU_AHB_3_2:
printk(KERN_CONT "(3/2)\n");
break;
case CPU_AHB_24_13:
printk(KERN_CONT "(24/13)\n");
break;
case CPU_AHB_2_1:
printk(KERN_CONT "(2/1)\n");
break;
}
/*
* Make irqs happen for the system timer
*/
setup_irq(IRQ_TIMER2, &gemini_timer_irq);
/* Start the timer */
__raw_writel(tick_rate / HZ, TIMER_COUNT(IO_ADDRESS(GEMINI_TIMER2_BASE)));
__raw_writel(tick_rate / HZ, TIMER_LOAD(IO_ADDRESS(GEMINI_TIMER2_BASE)));
__raw_writel(TIMER_2_CR_ENABLE | TIMER_2_CR_INT, TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE)));
}