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Diffstat (limited to 'arch/arm/include/asm/macro.h')
-rw-r--r-- | arch/arm/include/asm/macro.h | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/arch/arm/include/asm/macro.h b/arch/arm/include/asm/macro.h new file mode 100644 index 0000000..57b5260 --- /dev/null +++ b/arch/arm/include/asm/macro.h @@ -0,0 +1,74 @@ +/* + * include/asm-arm/macro.h + * + * Copyright (C) 2009 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> + * + * 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__ */ |