diff options
Diffstat (limited to 'x-loader/cpu/arm926ejs/cpu.c')
| m--------- | x-loader | 0 | ||||
| -rw-r--r-- | x-loader/cpu/arm926ejs/cpu.c | 126 |
2 files changed, 126 insertions, 0 deletions
diff --git a/x-loader b/x-loader deleted file mode 160000 -Subproject 1c9276af4d6a5b7014a7630a1abeddf3b317756 diff --git a/x-loader/cpu/arm926ejs/cpu.c b/x-loader/cpu/arm926ejs/cpu.c new file mode 100644 index 0000000..972fa8a --- /dev/null +++ b/x-loader/cpu/arm926ejs/cpu.c @@ -0,0 +1,126 @@ +/* + * (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 */ + |