/* * Copyright (C) 2004-2006 Atmel Corporation * * See file CREDITS for list of people who contributed to this * project. * * 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 */ #include <common.h> #include <div64.h> #include <asm/errno.h> #include <asm/io.h> #include <asm/processor.h> #include <asm/sysreg.h> #include <asm/arch/memory-map.h> #define HANDLER_MASK 0x00ffffff #define INTLEV_SHIFT 30 #define INTLEV_MASK 0x00000003 DECLARE_GLOBAL_DATA_PTR; /* Incremented whenever COUNT reaches 0xffffffff by timer_interrupt_handler */ volatile unsigned long timer_overflow; /* * Instead of dividing by get_tbclk(), multiply by this constant and * right-shift the result by 32 bits. */ static unsigned long tb_factor; unsigned long get_tbclk(void) { return gd->cpu_hz; } unsigned long long get_ticks(void) { unsigned long lo, hi_now, hi_prev; do { hi_prev = timer_overflow; lo = sysreg_read(COUNT); hi_now = timer_overflow; } while (hi_prev != hi_now); return ((unsigned long long)hi_now << 32) | lo; } void reset_timer(void) { sysreg_write(COUNT, 0); cpu_sync_pipeline(); /* process any pending interrupts */ timer_overflow = 0; } unsigned long get_timer(unsigned long base) { u64 now = get_ticks(); now *= tb_factor; return (unsigned long)(now >> 32) - base; } void set_timer(unsigned long t) { unsigned long long ticks = t; unsigned long lo, hi, hi_new; ticks = (ticks * get_tbclk()) / CONFIG_SYS_HZ; hi = ticks >> 32; lo = ticks & 0xffffffffUL; do { timer_overflow = hi; sysreg_write(COUNT, lo); hi_new = timer_overflow; } while (hi_new != hi); } /* * For short delays only. It will overflow after a few seconds. */ void udelay(unsigned long usec) { unsigned long cycles; unsigned long base; unsigned long now; base = sysreg_read(COUNT); cycles = ((usec * (get_tbclk() / 10000)) + 50) / 100; do { now = sysreg_read(COUNT); } while ((now - base) < cycles); } static int set_interrupt_handler(unsigned int nr, void (*handler)(void), unsigned int priority) { extern void _evba(void); unsigned long intpr; unsigned long handler_addr = (unsigned long)handler; handler_addr -= (unsigned long)&_evba; if ((handler_addr & HANDLER_MASK) != handler_addr || (priority & INTLEV_MASK) != priority) return -EINVAL; intpr = (handler_addr & HANDLER_MASK); intpr |= (priority & INTLEV_MASK) << INTLEV_SHIFT; writel(intpr, (void *)INTC_BASE + 4 * nr); return 0; } void timer_init(void) { extern void timer_interrupt_handler(void); u64 tmp; sysreg_write(COUNT, 0); tmp = (u64)CONFIG_SYS_HZ << 32; tmp += gd->cpu_hz / 2; do_div(tmp, gd->cpu_hz); tb_factor = (u32)tmp; if (set_interrupt_handler(0, &timer_interrupt_handler, 3)) return; /* For all practical purposes, this gives us an overflow interrupt */ sysreg_write(COMPARE, 0xffffffff); }