/* * include/asm-arm/macro.h * * Copyright (C) 2009 Jean-Christophe PLAGNIOL-VILLARD * * SPDX-License-Identifier: GPL-2.0+ */ #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__ */