diff options
Diffstat (limited to 'lib_ppc')
-rw-r--r-- | lib_ppc/ticks.S | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/lib_ppc/ticks.S b/lib_ppc/ticks.S new file mode 100644 index 0000000..b8d25b7 --- /dev/null +++ b/lib_ppc/ticks.S @@ -0,0 +1,65 @@ +/* + * (C) Copyright 2000, 2001 + * Erik Theisen, Wave 7 Optics, etheisen@mindspring.com. + * base on code by + * 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 <ppc_asm.tmpl> +#include <ppc_defs.h> +#include <config.h> +#include <watchdog.h> + +/* + * unsigned long long get_ticks(void); + * + * read timebase as "long long" + */ + .globl get_ticks +get_ticks: +1: mftbu r3 + mftb r4 + mftbu r5 + cmp 0,r3,r5 + bne 1b + blr + +/* + * Delay for a number of ticks + */ + .globl wait_ticks +wait_ticks: + mflr r8 /* save link register */ + mr r7, r3 /* save tick count */ + bl get_ticks /* Get start time */ + + /* Calculate end time */ + addc r7, r4, r7 /* Compute end time lower */ + addze r6, r3 /* and end time upper */ + + WATCHDOG_RESET /* Trigger watchdog, if needed */ +1: bl get_ticks /* Get current time */ + subfc r4, r4, r7 /* Subtract current time from end time */ + subfe. r3, r3, r6 + bge 1b /* Loop until time expired */ + + mtlr r8 /* restore link register */ + blr |