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Diffstat (limited to 'cpu/arm926ejs/mx28/timer.c')
| -rw-r--r-- | cpu/arm926ejs/mx28/timer.c | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/cpu/arm926ejs/mx28/timer.c b/cpu/arm926ejs/mx28/timer.c new file mode 100644 index 0000000..ffad4d8 --- /dev/null +++ b/cpu/arm926ejs/mx28/timer.c @@ -0,0 +1,245 @@ +/* + * (C) Copyright 2003 + * Texas Instruments <www.ti.com> + * + * (C) Copyright 2002 + * Sysgo Real-Time Solutions, GmbH <www.elinos.com> + * Marius Groeger <mgroeger@sysgo.de> + * + * (C) Copyright 2002 + * Sysgo Real-Time Solutions, GmbH <www.elinos.com> + * Alex Zuepke <azu@sysgo.de> + * + * (C) Copyright 2002-2004 + * Gary Jennejohn, DENX Software Engineering, <gj@denx.de> + * + * (C) Copyright 2004 + * Philippe Robin, ARM Ltd. <philippe.robin@arm.com> + * + * (C) Copyright 2009 Freescale Semiconductor, Inc. + * + * 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/mx28.h> +#include <asm/arch/timrot.h> + +#define CONFIG_USE_TIMER0 + +#if defined(CONFIG_USE_TIMER0) +#define TIMCTRL TIMCTRL0 +#define TIMCOUNT TIMCOUNT0 +#elif defined(CONFIG_USE_TIMER1) +#define TIMCTRL TIMCTRL1 +#define TIMCOUNT TIMCOUNT1 +#elif defined(CONFIG_USE_TIMER2) +#define TIMCTRL TIMCTRL2 +#define TIMCOUNT TIMCOUNT2 +#elif defined(CONFIG_USE_TIMER3) +#define TIMCTRL TIMCTRL3 +#define TIMCOUNT TIMCOUNT3 +#else +#error "Define which STMP378x timer to use" +#endif + +#define TIMER_LOAD_VAL 0x0000ffff + +/* macro to read the 16 bit timer */ +#define READ_TIMER ((REG_RD(TIMROT_BASE + TIMCOUNT) & 0xffff0000) >> 16) + +static ulong timestamp; +static ulong lastdec; + +int timer_init(void) +{ + u32 val; + + /* + * Reset Timers and Rotary Encoder module + */ + + /* Clear SFTRST */ + REG_CLR(TIMROT_BASE + ROTCTRL, 1 << 31); + while (REG_RD(TIMROT_BASE + ROTCTRL) & (1 << 31)) + ; + + /* Clear CLKGATE */ + REG_CLR(TIMROT_BASE + ROTCTRL, 1 << 30); + + /* Set SFTRST and wait until CLKGATE is set */ + REG_SET(TIMROT_BASE + ROTCTRL, 1 << 31); + while (!(REG_RD(TIMROT_BASE + ROTCTRL) & (1 << 30))) + ; + + /* Clear SFTRST and CLKGATE */ + REG_CLR(TIMROT_BASE + ROTCTRL, 1 << 31); + REG_CLR(TIMROT_BASE + ROTCTRL, 1 << 30); + + /* + * Now initialize timer + */ + + /* Set fixed_count to 0 */ + REG_WR(TIMROT_BASE + TIMCOUNT, 0); + + /* set UPDATE bit and 1Khz frequency */ + REG_WR(TIMROT_BASE + TIMCTRL, + TIMCTRL_RELOAD | TIMCTRL_UPDATE | TIMCTRL_SELECT_1KHZ); + + /* Set fixed_count to maximal value */ + REG_WR(TIMROT_BASE + TIMCOUNT, TIMER_LOAD_VAL); + + /* init the timestamp and lastdec value */ + reset_timer_masked(); + + return 0; +} + +/* + * timer without interrupts + */ + +void reset_timer(void) +{ + reset_timer_masked(); +} + +ulong get_timer(ulong base) +{ + return get_timer_masked() - base; +} + +void set_timer(ulong t) +{ + timestamp = t; +} + +/* delay x useconds AND perserve advance timstamp value */ +void udelay(unsigned long usec) +{ + ulong tmo, tmp; + + if (usec >= 1000) { + /* if "big" number, spread normalization to seconds */ + tmo = usec / 1000; + /* start to normalize for usec to ticks per sec */ + tmo *= CONFIG_SYS_HZ; + /* find number of "ticks" to wait to achieve target */ + tmo /= 1000; + /* finish normalize. */ + } else { + /* else small number, don't kill it prior to HZ multiply */ + tmo = usec * CONFIG_SYS_HZ; + tmo /= (1000*1000); + } + + tmp = get_timer(0); + /* get current timestamp */ + if ((tmo + tmp + 1) < tmp) + /* if setting this fordward will roll time stamp */ + reset_timer_masked(); + /* reset "advancing" timestamp to 0, set lastdec value */ + else + tmo += tmp; + /* else, set advancing stamp wake up time */ + + while (get_timer_masked() < tmo)/* loop till event */ + /*NOP*/; +} + +void reset_timer_masked(void) +{ + /* reset time */ + lastdec = READ_TIMER; /* capure current decrementer value time */ + timestamp = 0; /* start "advancing" time stamp from 0 */ +} + +ulong get_timer_masked(void) +{ + ulong now = READ_TIMER; /* current tick value */ + + if (lastdec >= now) { /* normal mode (non roll) */ + /* normal mode */ + timestamp += lastdec - now; + /* move stamp fordward with absoulte diff ticks */ + } else { + /* we have overflow of the count down timer */ + /* nts = ts + ld + (TLV - now) + * ts=old stamp, ld=time that passed before passing through -1 + * (TLV-now) amount of time after passing though -1 + * nts = new "advancing time stamp"...it could also roll + * and cause problems. + */ + timestamp += lastdec + TIMER_LOAD_VAL - now + 1; + } + lastdec = now; + + return timestamp; +} + +/* waits specified delay value and resets timestamp */ +void udelay_masked(unsigned long usec) +{ + ulong tmo; + ulong endtime; + signed long diff; + + if (usec >= 1000) { + /* if "big" number, spread normalization to seconds */ + tmo = usec / 1000; + /* start to normalize for usec to ticks per sec */ + tmo *= CONFIG_SYS_HZ; + /* find number of "ticks" to wait to achieve target */ + tmo /= 1000; + /* finish normalize. */ + } else { + /* else small number, don't kill it prior to HZ multiply */ + tmo = usec * CONFIG_SYS_HZ; + tmo /= (1000*1000); + } + + endtime = get_timer_masked() + tmo; + + do { + ulong now = get_timer_masked(); + diff = endtime - now; + } while (diff >= 0); +} + +/* + * 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 = CONFIG_SYS_HZ; + return tbclk; +} |