151 lines
3.4 KiB
C
151 lines
3.4 KiB
C
/*
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* Copyright (C) 2004-2006 Atmel Corporation
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*
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* See file CREDITS for list of people who contributed to this
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* project.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*/
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#include <common.h>
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#include <div64.h>
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#include <asm/errno.h>
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#include <asm/io.h>
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#include <asm/processor.h>
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#include <asm/sysreg.h>
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#include <asm/arch/memory-map.h>
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#define HANDLER_MASK 0x00ffffff
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#define INTLEV_SHIFT 30
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#define INTLEV_MASK 0x00000003
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DECLARE_GLOBAL_DATA_PTR;
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/* Incremented whenever COUNT reaches 0xffffffff by timer_interrupt_handler */
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volatile unsigned long timer_overflow;
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/*
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* Instead of dividing by get_tbclk(), multiply by this constant and
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* right-shift the result by 32 bits.
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*/
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static unsigned long tb_factor;
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unsigned long get_tbclk(void)
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{
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return gd->cpu_hz;
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}
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unsigned long long get_ticks(void)
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{
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unsigned long lo, hi_now, hi_prev;
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do {
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hi_prev = timer_overflow;
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lo = sysreg_read(COUNT);
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hi_now = timer_overflow;
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} while (hi_prev != hi_now);
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return ((unsigned long long)hi_now << 32) | lo;
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}
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void reset_timer(void)
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{
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sysreg_write(COUNT, 0);
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cpu_sync_pipeline(); /* process any pending interrupts */
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timer_overflow = 0;
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}
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unsigned long get_timer(unsigned long base)
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{
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u64 now = get_ticks();
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now *= tb_factor;
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return (unsigned long)(now >> 32) - base;
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}
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void set_timer(unsigned long t)
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{
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unsigned long long ticks = t;
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unsigned long lo, hi, hi_new;
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ticks = (ticks * get_tbclk()) / CONFIG_SYS_HZ;
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hi = ticks >> 32;
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lo = ticks & 0xffffffffUL;
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do {
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timer_overflow = hi;
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sysreg_write(COUNT, lo);
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hi_new = timer_overflow;
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} while (hi_new != hi);
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}
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/*
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* For short delays only. It will overflow after a few seconds.
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*/
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void udelay(unsigned long usec)
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{
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unsigned long cycles;
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unsigned long base;
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unsigned long now;
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base = sysreg_read(COUNT);
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cycles = ((usec * (get_tbclk() / 10000)) + 50) / 100;
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do {
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now = sysreg_read(COUNT);
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} while ((now - base) < cycles);
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}
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static int set_interrupt_handler(unsigned int nr, void (*handler)(void),
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unsigned int priority)
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{
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extern void _evba(void);
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unsigned long intpr;
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unsigned long handler_addr = (unsigned long)handler;
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handler_addr -= (unsigned long)&_evba;
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if ((handler_addr & HANDLER_MASK) != handler_addr
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|| (priority & INTLEV_MASK) != priority)
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return -EINVAL;
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intpr = (handler_addr & HANDLER_MASK);
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intpr |= (priority & INTLEV_MASK) << INTLEV_SHIFT;
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writel(intpr, (void *)INTC_BASE + 4 * nr);
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return 0;
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}
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void timer_init(void)
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{
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extern void timer_interrupt_handler(void);
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u64 tmp;
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sysreg_write(COUNT, 0);
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tmp = (u64)CONFIG_SYS_HZ << 32;
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tmp += gd->cpu_hz / 2;
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do_div(tmp, gd->cpu_hz);
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tb_factor = (u32)tmp;
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if (set_interrupt_handler(0, &timer_interrupt_handler, 3))
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return;
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/* For all practical purposes, this gives us an overflow interrupt */
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sysreg_write(COMPARE, 0xffffffff);
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}
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