/* * include/asm-arm/macro.h * * Copyright (C) 2009 Jean-Christophe PLAGNIOL-VILLARD * * 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 */ #ifndef __ASM_ARM_MACRO_H__ #define __ASM_ARM_MACRO_H__ #ifdef __ASSEMBLY__ /* * These macros provide a convenient way to write 8, 16 and 32 bit data * to any address. * Registers r4 and r5 are used, any data in these registers are * overwritten by the macros. * The macros are valid for any ARM architecture, they do not implement * any memory barriers so caution is recommended when using these when the * caches are enabled or on a multi-core system. */ .macro write32, addr, data ldr r4, =\addr ldr r5, =\data str r5, [r4] .endm .macro write16, addr, data ldr r4, =\addr ldrh r5, =\data strh r5, [r4] .endm .macro write8, addr, data ldr r4, =\addr ldrb r5, =\data strb r5, [r4] .endm /* * This macro generates a loop that can be used for delays in the code. * Register r4 is used, any data in this register is overwritten by the * macro. * The macro is valid for any ARM architeture. The actual time spent in the * loop will vary from CPU to CPU though. */ .macro wait_timer, time ldr r4, =\time 1: nop subs r4, r4, #1 bcs 1b .endm #endif /* __ASSEMBLY__ */ #endif /* __ASM_ARM_MACRO_H__ */