uboot/u-boot-stm32mp-2020.01/arch/arm/include/asm/arch-armv7/generictimer.h

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2024-01-10 06:52:34 +00:00
/*
* Copyright (C) 2013 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*
* Based on code by Carl van Schaik <carl@ok-labs.com>.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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, see <http://www.gnu.org/licenses/>.
*/
#ifndef _GENERICTIMER_H_
#define _GENERICTIMER_H_
#ifdef __ASSEMBLY__
/*
* This macro provide a physical timer that can be used for delay in the code.
* The macro is moved from sunxi/psci_sun7i.S
*
* reg: is used in this macro.
* ticks: The freq is based on generic timer.
*/
.macro timer_wait reg, ticks
movw \reg, #(\ticks & 0xffff)
movt \reg, #(\ticks >> 16)
mcr p15, 0, \reg, c14, c2, 0
isb
mov \reg, #3
mcr p15, 0, \reg, c14, c2, 1
1 : isb
mrc p15, 0, \reg, c14, c2, 1
ands \reg, \reg, #4
bne 1b
mov \reg, #0
mcr p15, 0, \reg, c14, c2, 1
isb
.endm
#endif /* __ASSEMBLY__ */
#endif /* _GENERICTIMER_H_ */