00001 /***************************************************************************** 00002 *! 00003 *! FILE NAME : delay.c 00004 *! 00005 *! DESCRIPTION: Precise delay loops for ETRAX FS. 00006 *! Trivial mod. for boot loader. 00007 *! 00008 *! --------------------------------------------------------------------------- 00009 *! (C) Copyright 2006-2007, Axis Communications AB, LUND, SWEDEN 00010 *! 00011 *! This program is free software; you can redistribute it and/or modify 00012 *! it under the terms of the GNU General Public License version 2 as 00013 *! published by the Free Software Foundation. 00014 *! 00015 *! This program is distributed in the hope that it will be useful, 00016 *! but WITHOUT ANY WARRANTY; without even the implied warranty of 00017 *! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00018 *! GNU General Public License for more details. 00019 *! 00020 *! You should have received a copy of the GNU General Public License 00021 *! along with this program; if not, write to the Free Software 00022 *! Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 00023 *! 00024 *!***************************************************************************/ 00025 00026 #include <asm/arch/hwregs/reg_map.h> 00027 #include <asm/arch/hwregs/reg_rdwr.h> 00028 #include <asm/arch/hwregs/timer_defs.h> 00029 #include <linux/types.h> 00030 #include "delay.h" 00031 00032 /* 00033 * On ETRAX FS, we can check the free-running read-only 100MHz timer 00034 * getting 32-bit 10ns precision, theoretically good for 42.94967295 00035 * seconds. Unsigned arithmetic and careful expression handles 00036 * wrapping. 00037 */ 00038 00039 void cris_delay10ns(u32 n10ns) 00040 { 00041 u32 t0 = REG_RD(timer, regi_timer, r_time); 00042 while (REG_RD(timer, regi_timer, r_time) - t0 < n10ns) 00043 ; 00044 }
1.5.1