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author | Sascha Hauer <s.hauer@pengutronix.de> | 2007-07-05 18:01:28 +0200 |
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committer | Sascha Hauer <sha@octopus.labnet.pengutronix.de> | 2007-07-05 18:01:28 +0200 |
commit | ceddda143b55019ed6be8a331b5ed218a1c64d3b (patch) | |
tree | da946924eb3e5fbdf86367e0d45deaaf8e931885 /arch/ppc/time.c | |
parent | 2e8ca97d8d56683c40c2fa6c0c1bf3699c9cddb5 (diff) | |
download | barebox-ceddda143b55019ed6be8a331b5ed218a1c64d3b.tar.gz barebox-ceddda143b55019ed6be8a331b5ed218a1c64d3b.tar.xz |
svn_rev_154
move lib_ppc to arch/ppc
Diffstat (limited to 'arch/ppc/time.c')
-rw-r--r-- | arch/ppc/time.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/arch/ppc/time.c b/arch/ppc/time.c new file mode 100644 index 0000000000..51e8e8406d --- /dev/null +++ b/arch/ppc/time.c @@ -0,0 +1,99 @@ +/* + * (C) Copyright 2000, 2001 + * Wolfgang Denk, DENX Software Engineering, wd@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> + + +/* ------------------------------------------------------------------------- */ + +/* + * This function is intended for SHORT delays only. + * It will overflow at around 10 seconds @ 400MHz, + * or 20 seconds @ 200MHz. + */ +unsigned long usec2ticks(unsigned long usec) +{ + ulong ticks; + + if (usec < 1000) { + ticks = ((usec * (get_tbclk()/1000)) + 500) / 1000; + } else { + ticks = ((usec / 10) * (get_tbclk() / 100000)); + } + + return (ticks); +} + +/* ------------------------------------------------------------------------- */ + +/* + * We implement the delay by converting the delay (the number of + * microseconds to wait) into a number of time base ticks; then we + * watch the time base until it has incremented by that amount. + */ +void udelay(unsigned long usec) +{ + ulong ticks = usec2ticks (usec); + + wait_ticks (ticks); +} + +/* ------------------------------------------------------------------------- */ + +unsigned long ticks2usec(unsigned long ticks) +{ + ulong tbclk = get_tbclk(); + + /* usec = ticks * 1000000 / tbclk + * Multiplication would overflow at ~4.2e3 ticks, + * so we break it up into + * usec = ( ( ticks * 1000) / tbclk ) * 1000; + */ + ticks *= 1000L; + ticks /= tbclk; + ticks *= 1000L; + + return ((ulong)ticks); +} + +/* ------------------------------------------------------------------------- */ + +int init_timebase (void) +{ +#if defined(CONFIG_5xx) || defined(CONFIG_8xx) + volatile immap_t *immap = (immap_t *) CFG_IMMR; + + /* unlock */ + immap->im_sitk.sitk_tbk = KAPWR_KEY; +#endif + + /* reset */ + asm ("li 3,0 ; mttbu 3 ; mttbl 3 ;"); + +#if defined(CONFIG_5xx) || defined(CONFIG_8xx) + /* enable */ + immap->im_sit.sit_tbscr |= TBSCR_TBE; +#endif + return (0); +} +/* ------------------------------------------------------------------------- */ |