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| /* SPDX-License-Identifier: GPL-2.0-only */
| /*
| * linux/arch/arm/lib/delay.S
| *
| * Copyright (C) 1995, 1996 Russell King
| */
| #include <linux/linkage.h>
| #include <asm/assembler.h>
| #include <asm/delay.h>
|
| .text
|
| .LC0: .word loops_per_jiffy
| .LC1: .word UDELAY_MULT
|
| /*
| * loops = r0 * HZ * loops_per_jiffy / 1000000
| *
| * r0 <= 2000
| * HZ <= 1000
| */
|
| ENTRY(__loop_udelay)
| ldr r2, .LC1
| mul r0, r2, r0 @ r0 = delay_us * UDELAY_MULT
| ENTRY(__loop_const_udelay) @ 0 <= r0 <= 0xfffffaf0
| ldr r2, .LC0
| ldr r2, [r2]
| umull r1, r0, r2, r0 @ r0-r1 = r0 * loops_per_jiffy
| adds r1, r1, #0xffffffff @ rounding up ...
| adcs r0, r0, r0 @ and right shift by 31
| reteq lr
|
| .align 3
|
| @ Delay routine
| ENTRY(__loop_delay)
| subs r0, r0, #1
| #if 0
| retls lr
| subs r0, r0, #1
| retls lr
| subs r0, r0, #1
| retls lr
| subs r0, r0, #1
| retls lr
| subs r0, r0, #1
| retls lr
| subs r0, r0, #1
| retls lr
| subs r0, r0, #1
| retls lr
| subs r0, r0, #1
| #endif
| bhi __loop_delay
| ret lr
| ENDPROC(__loop_udelay)
| ENDPROC(__loop_const_udelay)
| ENDPROC(__loop_delay)
|
|
