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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/nds32/include/asm/delay.h
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/nds32/include/asm/delay.h')
-rw-r--r--arch/nds32/include/asm/delay.h39
1 files changed, 39 insertions, 0 deletions
diff --git a/arch/nds32/include/asm/delay.h b/arch/nds32/include/asm/delay.h
new file mode 100644
index 000000000..519ba97ac
--- /dev/null
+++ b/arch/nds32/include/asm/delay.h
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#ifndef __NDS32_DELAY_H__
+#define __NDS32_DELAY_H__
+
+#include <asm/param.h>
+
+/* There is no clocksource cycle counter in the CPU. */
+static inline void __delay(unsigned long loops)
+{
+ __asm__ __volatile__(".align 2\n"
+ "1:\n"
+ "\taddi\t%0, %0, -1\n"
+ "\tbgtz\t%0, 1b\n"
+ :"=r"(loops)
+ :"0"(loops));
+}
+
+static inline void __udelay(unsigned long usecs, unsigned long lpj)
+{
+ usecs *= (unsigned long)(((0x8000000000000000ULL / (500000 / HZ)) +
+ 0x80000000ULL) >> 32);
+ usecs = (unsigned long)(((unsigned long long)usecs * lpj) >> 32);
+ __delay(usecs);
+}
+
+#define udelay(usecs) __udelay((usecs), loops_per_jiffy)
+
+/* make sure "usecs *= ..." in udelay do not overflow. */
+#if HZ >= 1000
+#define MAX_UDELAY_MS 1
+#elif HZ <= 200
+#define MAX_UDELAY_MS 5
+#else
+#define MAX_UDELAY_MS (1000 / HZ)
+#endif
+
+#endif