101 lines
2.2 KiB
C
101 lines
2.2 KiB
C
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/*
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* linux/arch/arm/mach-nuc93x/time.c
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*
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* Copyright (c) 2009 Nuvoton technology corporation.
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*
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* Wan ZongShun <mcuos.com@gmail.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/err.h>
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#include <linux/clk.h>
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#include <linux/io.h>
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#include <linux/leds.h>
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#include <asm/mach-types.h>
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#include <asm/mach/irq.h>
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#include <asm/mach/time.h>
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#include <mach/system.h>
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#include <mach/map.h>
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#include <mach/regs-timer.h>
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#define RESETINT 0x01
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#define PERIOD (0x01 << 27)
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#define ONESHOT (0x00 << 27)
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#define COUNTEN (0x01 << 30)
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#define INTEN (0x01 << 29)
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#define TICKS_PER_SEC 100
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#define PRESCALE 0x63 /* Divider = prescale + 1 */
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unsigned int timer0_load;
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static unsigned long nuc93x_gettimeoffset(void)
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{
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return 0;
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}
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/*IRQ handler for the timer*/
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static irqreturn_t nuc93x_timer_interrupt(int irq, void *dev_id)
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{
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timer_tick();
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__raw_writel(0x01, REG_TISR); /* clear TIF0 */
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return IRQ_HANDLED;
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}
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static struct irqaction nuc93x_timer_irq = {
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.name = "nuc93x Timer Tick",
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.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
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.handler = nuc93x_timer_interrupt,
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};
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/*Set up timer reg.*/
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static void nuc93x_timer_setup(void)
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{
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struct clk *ck_ext = clk_get(NULL, "ext");
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struct clk *ck_timer = clk_get(NULL, "timer");
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unsigned int rate, val = 0;
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BUG_ON(IS_ERR(ck_ext) || IS_ERR(ck_timer));
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clk_enable(ck_timer);
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rate = clk_get_rate(ck_ext);
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clk_put(ck_ext);
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rate = rate / (PRESCALE + 0x01);
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/* set a known state */
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__raw_writel(0x00, REG_TCSR0);
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__raw_writel(RESETINT, REG_TISR);
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timer0_load = (rate / TICKS_PER_SEC);
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__raw_writel(timer0_load, REG_TICR0);
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val |= (PERIOD | COUNTEN | INTEN | PRESCALE);;
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__raw_writel(val, REG_TCSR0);
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}
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static void __init nuc93x_timer_init(void)
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{
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nuc93x_timer_setup();
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setup_irq(IRQ_TIMER0, &nuc93x_timer_irq);
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}
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struct sys_timer nuc93x_timer = {
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.init = nuc93x_timer_init,
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.offset = nuc93x_gettimeoffset,
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.resume = nuc93x_timer_setup
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};
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