/* * (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); } /* ------------------------------------------------------------------------- */