v4.19.13 snapshot.
diff --git a/arch/mips/include/asm/m48t37.h b/arch/mips/include/asm/m48t37.h
new file mode 100644
index 0000000..3687a02
--- /dev/null
+++ b/arch/mips/include/asm/m48t37.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Registers for the SGS-Thomson M48T37 Timekeeper RAM chip
+ */
+#ifndef _ASM_M48T37_H
+#define _ASM_M48T37_H
+
+#include <linux/spinlock.h>
+
+extern spinlock_t rtc_lock;
+
+struct m48t37_rtc {
+ volatile u8 pad[0x7ff0]; /* NVRAM */
+ volatile u8 flags;
+ volatile u8 century;
+ volatile u8 alarm_sec;
+ volatile u8 alarm_min;
+ volatile u8 alarm_hour;
+ volatile u8 alarm_data;
+ volatile u8 interrupts;
+ volatile u8 watchdog;
+ volatile u8 control;
+ volatile u8 sec;
+ volatile u8 min;
+ volatile u8 hour;
+ volatile u8 day;
+ volatile u8 date;
+ volatile u8 month;
+ volatile u8 year;
+};
+
+#define M48T37_RTC_SET 0x80
+#define M48T37_RTC_STOPPED 0x80
+#define M48T37_RTC_READ 0x40
+
+#endif /* _ASM_M48T37_H */