From 84ad688473bec2875e171b71040eb9e033c6c206 Mon Sep 17 00:00:00 2001 From: Peter Tyser Date: Mon, 12 Apr 2010 22:28:11 -0500 Subject: arm: Move cpu/$CPU to arch/arm/cpu/$CPU Signed-off-by: Peter Tyser --- arch/arm/cpu/arm926ejs/at91/timer.c | 145 ++++++++++++++++++++++++++++++++++++ 1 file changed, 145 insertions(+) create mode 100644 arch/arm/cpu/arm926ejs/at91/timer.c (limited to 'arch/arm/cpu/arm926ejs/at91/timer.c') diff --git a/arch/arm/cpu/arm926ejs/at91/timer.c b/arch/arm/cpu/arm926ejs/at91/timer.c new file mode 100644 index 0000000..d21eebf --- /dev/null +++ b/arch/arm/cpu/arm926ejs/at91/timer.c @@ -0,0 +1,145 @@ +/* + * (C) Copyright 2007-2008 + * Stelian Pop + * Lead Tech Design + * + * 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 +#include +#include +#include +#include +#include +#include + +/* + * 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 + +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) +{ + at91_pmc_t *pmc = (at91_pmc_t *) AT91_PMC_BASE; + at91_pit_t *pit = (at91_pit_t *) AT91_PIT_BASE; + /* + * Enable PITC Clock + * The clock is already enabled for system controller in boot + */ + writel(1 << AT91_ID_SYS, &pmc->pcer); + + /* Enable PITC */ + writel(TIMER_LOAD_VAL | AT91_PIT_MR_EN , &pit->mr); + + reset_timer_masked(); + + timer_freq = get_mck_clk_rate() >> 4; + + return 0; +} + +/* + * timer without interrupts + */ +unsigned long long get_ticks(void) +{ + at91_pit_t *pit = (at91_pit_t *) AT91_PIT_BASE; + + ulong now = readl(&pit->piir); + + 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 */ + at91_pit_t *pit = (at91_pit_t *) AT91_PIT_BASE; + + /* capture current incrementer value time */ + lastinc = readl(&pit->piir); + 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; +} -- cgit v1.1