/* * (C) Copyright 2007-2008 * Stelian Pop <stelian.pop@leadtechdesign.com> * Lead Tech Design <www.leadtechdesign.com> * * 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 <asm/arch/hardware.h> #include <asm/arch/at91_pit.h> #include <asm/arch/at91_pmc.h> #include <asm/arch/clk.h> #include <asm/arch/io.h> #include <div64.h> /* * We're using the AT91CAP9/SAM9 PITC in 32 bit mode, by * setting the 20 bit counter period to its maximum (0xfffff). */ #define TIMER_LOAD_VAL 0xfffff #define READ_RESET_TIMER at91_sys_read(AT91_PIT_PIVR) #define READ_TIMER at91_sys_read(AT91_PIT_PIIR) static ulong timestamp; static ulong lastinc; static ulong timer_freq; static inline unsigned long long tick_to_time(unsigned long long tick) { tick *= CONFIG_SYS_HZ; do_div(tick, timer_freq); return tick; } static inline unsigned long long usec_to_tick(unsigned long long usec) { usec *= timer_freq; do_div(usec, 1000000); return usec; } /* nothing really to do with interrupts, just starts up a counter. */ int timer_init(void) { /* * Enable PITC Clock * The clock is already enabled for system controller in boot */ at91_sys_write(AT91_PMC_PCER, 1 << AT91_ID_SYS); /* Enable PITC */ at91_sys_write(AT91_PIT_MR, TIMER_LOAD_VAL | AT91_PIT_PITEN); reset_timer_masked(); timer_freq = get_mck_clk_rate() >> 4; return 0; } /* * timer without interrupts */ unsigned long long get_ticks(void) { ulong now = READ_TIMER; if (now >= lastinc) /* normal mode (non roll) */ /* move stamp forward with absolut diff ticks */ timestamp += (now - lastinc); else /* we have rollover of incrementer */ timestamp += (0xFFFFFFFF - lastinc) + now; lastinc = now; return timestamp; } void reset_timer_masked(void) { /* reset time */ lastinc = READ_TIMER; /* capture current incrementer value time */ timestamp = 0; /* start "advancing" time stamp from 0 */ } ulong get_timer_masked(void) { return tick_to_time(get_ticks()); } void udelay(unsigned long usec) { unsigned long long tmp; ulong tmo; tmo = usec_to_tick(usec); tmp = get_ticks() + tmo; /* get current timestamp */ while (get_ticks() < tmp) /* loop till event */ /*NOP*/; } void reset_timer(void) { reset_timer_masked(); } ulong get_timer(ulong base) { return get_timer_masked () - base; } /* * This function is derived from PowerPC code (timebase clock frequency). * On ARM it returns the number of timer ticks per second. */ ulong get_tbclk(void) { ulong tbclk; tbclk = CONFIG_SYS_HZ; return tbclk; }