/* * (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, <garyj@denx.de> * * (C) Copyright 2004 * Philippe Robin, ARM Ltd. <philippe.robin@arm.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> #define TIMER_LOAD_VAL 0xffffffff /* macro to read the 32 bit timer */ #define READ_TIMER (*(volatile ulong *)(CONFIG_SYS_TIMERBASE+4)) static ulong timestamp; static ulong lastdec; #define TIMER_ENABLE (1 << 7) #define TIMER_MODE_MSK (1 << 6) #define TIMER_MODE_FR (0 << 6) #define TIMER_MODE_PD (1 << 6) #define TIMER_INT_EN (1 << 5) #define TIMER_PRS_MSK (3 << 2) #define TIMER_PRS_8S (1 << 3) #define TIMER_SIZE_MSK (1 << 2) #define TIMER_ONE_SHT (1 << 0) int timer_init (void) { ulong tmr_ctrl_val; /* 1st disable the Timer */ tmr_ctrl_val = *(volatile ulong *)(CONFIG_SYS_TIMERBASE + 8); tmr_ctrl_val &= ~TIMER_ENABLE; *(volatile ulong *)(CONFIG_SYS_TIMERBASE + 8) = tmr_ctrl_val; /* * The Timer Control Register has one Undefined/Shouldn't Use Bit * So we should do read/modify/write Operation */ /* * Timer Mode : Free Running * Interrupt : Disabled * Prescale : 8 Stage, Clk/256 * Tmr Siz : 16 Bit Counter * Tmr in Wrapping Mode */ tmr_ctrl_val = *(volatile ulong *)(CONFIG_SYS_TIMERBASE + 8); tmr_ctrl_val &= ~(TIMER_MODE_MSK | TIMER_INT_EN | TIMER_PRS_MSK | TIMER_SIZE_MSK | TIMER_ONE_SHT ); tmr_ctrl_val |= (TIMER_ENABLE | TIMER_PRS_8S); *(volatile ulong *)(CONFIG_SYS_TIMERBASE + 8) = tmr_ctrl_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; } 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; }