/* * (C) Copyright 2003 * Texas Instruments * * (C) Copyright 2002 * Sysgo Real-Time Solutions, GmbH * Marius Groeger * * (C) Copyright 2002 * Sysgo Real-Time Solutions, GmbH * Alex Zuepke * * (C) Copyright 2002-2004 * Gary Jennejohn, DENX Software Engineering, * * (C) Copyright 2004 * Philippe Robin, ARM Ltd. * * (C) Copyright 2009-2010 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 #include #include #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 MX23 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; }