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author | Wolfgang Denk <wd@denx.de> | 2008-04-08 00:16:36 +0200 |
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committer | Wolfgang Denk <wd@denx.de> | 2008-04-08 00:16:36 +0200 |
commit | a1b215e2a2a013327693f2fb990957b746f26cf5 (patch) | |
tree | c998a43b8022f623ac86a0de246d05ed36a86e9e /cpu/arm926ejs/at91sam9/timer.c | |
parent | f9eabcb357ea294e3e01bfe26841bf51d6bd8f05 (diff) | |
parent | b5873f1732b92a25690e1513b90dfb0d644f6697 (diff) | |
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Merge branch 'master' of git://www.denx.de/git/u-boot-at91
Diffstat (limited to 'cpu/arm926ejs/at91sam9/timer.c')
-rw-r--r-- | cpu/arm926ejs/at91sam9/timer.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/cpu/arm926ejs/at91sam9/timer.c b/cpu/arm926ejs/at91sam9/timer.c new file mode 100644 index 0000000..4e79466 --- /dev/null +++ b/cpu/arm926ejs/at91sam9/timer.c @@ -0,0 +1,149 @@ +/* + * (C) Copyright 2007-2008 + * Stelian Pop <stelian.pop <at> 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/at91_rstc.h> +#include <asm/arch/io.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) +#define TIMER_FREQ (AT91C_MASTER_CLOCK << 4) +#define TICKS_TO_USEC(ticks) ((ticks) / 6) + +ulong get_timer_masked(void); +ulong resettime; + +/* 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(); + + return 0; +} + +/* + * timer without interrupts + */ + +static inline ulong get_timer_raw(void) +{ + ulong now = READ_TIMER; + + if (now >= resettime) + return now - resettime; + else + return 0xFFFFFFFFUL - (resettime - now) ; +} + +void reset_timer_masked(void) +{ + resettime = READ_TIMER; +} + +ulong get_timer_masked(void) +{ + return TICKS_TO_USEC(get_timer_raw()); + +} + +void udelay_masked(unsigned long usec) +{ + ulong tmp; + + tmp = get_timer(0); + while (get_timer(tmp) < usec) /* our timer works in usecs */ + ; /* NOP */ +} + +void reset_timer(void) +{ + reset_timer_masked(); +} + +ulong get_timer(ulong base) +{ + ulong now = get_timer_masked(); + + if (now >= base) + return now - base; + else + return TICKS_TO_USEC(0xFFFFFFFFUL) - (base - now) ; +} + +void udelay(unsigned long usec) +{ + udelay_masked(usec); +} + +/* + * This function is derived from PowerPC code (read timebase as long long). + * On ARM it just returns the timer value. + */ +unsigned long long get_ticks(void) +{ + return get_timer(0); +} + +/* + * 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 = CFG_HZ; + return tbclk; +} + +/* + * Reset the cpu by setting up the watchdog timer and let him time out. + */ +void reset_cpu(ulong ignored) +{ + /* this is the way Linux does it */ + at91_sys_write(AT91_RSTC_CR, AT91_RSTC_KEY | + AT91_RSTC_PROCRST | + AT91_RSTC_PERRST); + + while (1); + /* Never reached */ +} |