summaryrefslogtreecommitdiffstats
path: root/arch/unicore32/lib/delay.S
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/unicore32/lib/delay.S
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/unicore32/lib/delay.S')
-rw-r--r--arch/unicore32/lib/delay.S51
1 files changed, 51 insertions, 0 deletions
diff --git a/arch/unicore32/lib/delay.S b/arch/unicore32/lib/delay.S
new file mode 100644
index 000000000..24664c009
--- /dev/null
+++ b/arch/unicore32/lib/delay.S
@@ -0,0 +1,51 @@
+/*
+ * linux/arch/unicore32/lib/delay.S
+ *
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ * Copyright (C) 2001-2010 GUAN Xue-tao
+ *
+ * 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.
+ */
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/param.h>
+ .text
+
+.LC0: .word loops_per_jiffy
+.LC1: .word (2199023*HZ)>>11
+
+/*
+ * r0 <= 2000
+ * lpj <= 0x01ffffff (max. 3355 bogomips)
+ * HZ <= 1000
+ */
+
+ENTRY(__udelay)
+ ldw r2, .LC1
+ mul r0, r2, r0
+ENTRY(__const_udelay) @ 0 <= r0 <= 0x7fffff06
+ ldw r2, .LC0
+ ldw r2, [r2] @ max = 0x01ffffff
+ mov r0, r0 >> #14 @ max = 0x0001ffff
+ mov r2, r2 >> #10 @ max = 0x00007fff
+ mul r0, r2, r0 @ max = 2^32-1
+ mov.a r0, r0 >> #6
+ cmoveq pc, lr
+
+/*
+ * loops = r0 * HZ * loops_per_jiffy / 1000000
+ *
+ * Oh, if only we had a cycle counter...
+ */
+
+@ Delay routine
+ENTRY(__delay)
+ sub.a r0, r0, #2
+ bua __delay
+ mov pc, lr
+ENDPROC(__udelay)
+ENDPROC(__const_udelay)
+ENDPROC(__delay)