| /* |
| * (C) Copyright 2004 |
| * Texas Instruments <www.ti.com> |
| * Jian Zhang <jzhang@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 |
| * Gary Jennejohn, DENX Software Engineering, <gj@denx.de> |
| * |
| * 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 *)(CFG_TIMERBASE+8)) |
| |
| static ulong timestamp; |
| static ulong lastdec; |
| |
| static void reset_timer_masked (void); |
| |
| /* nothing really to do with cpu, just starts up a counter. */ |
| int cpu_init (void) |
| { |
| int32_t val; |
| |
| /* Start the decrementer ticking down from 0xffffffff */ |
| *((int32_t *) (CFG_TIMERBASE + LOAD_TIM)) = TIMER_LOAD_VAL; |
| val = MPUTIM_ST | MPUTIM_AR | MPUTIM_CLOCK_ENABLE | (CFG_PVT << MPUTIM_PTV_BIT); |
| *((int32_t *) (CFG_TIMERBASE + CNTL_TIMER)) = val; |
| |
| /* init the timestamp and lastdec value */ |
| reset_timer_masked(); |
| |
| return (0); |
| } |
| |
| static void reset_timer_masked (void) |
| { |
| /* reset time */ |
| lastdec = READ_TIMER; /* capure current decrementer value time */ |
| timestamp = 0; /* start "advancing" time stamp from 0 */ |
| } |
| |
| #ifdef CFG_UDELAY |
| |
| static ulong get_timer_masked (void); |
| static ulong get_timer (ulong base); |
| |
| /* 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 *= CFG_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 * CFG_HZ; |
| tmo /= (1000*1000); |
| } |
| |
| tmp = get_timer (0); /* get current timestamp */ |
| if( (tmo + tmp) < 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*/; |
| } |
| |
| static 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; |
| } |
| |
| static ulong get_timer (ulong base) |
| { |
| return get_timer_masked () - base; |
| } |
| |
| #endif /* CFG_UDELAY */ |
| |