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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/arm/lib/delay-loop.S
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm/lib/delay-loop.S')
-rw-r--r--arch/arm/lib/delay-loop.S59
1 files changed, 59 insertions, 0 deletions
diff --git a/arch/arm/lib/delay-loop.S b/arch/arm/lib/delay-loop.S
new file mode 100644
index 000000000..3ccade0f8
--- /dev/null
+++ b/arch/arm/lib/delay-loop.S
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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)