v4.19.13 snapshot.
diff --git a/include/linux/i8042.h b/include/linux/i8042.h
new file mode 100644
index 0000000..d98780c
--- /dev/null
+++ b/include/linux/i8042.h
@@ -0,0 +1,99 @@
+#ifndef _LINUX_I8042_H
+#define _LINUX_I8042_H
+
+/*
+ * 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/types.h>
+
+/*
+ * Standard commands.
+ */
+
+#define I8042_CMD_CTL_RCTR	0x0120
+#define I8042_CMD_CTL_WCTR	0x1060
+#define I8042_CMD_CTL_TEST	0x01aa
+
+#define I8042_CMD_KBD_DISABLE	0x00ad
+#define I8042_CMD_KBD_ENABLE	0x00ae
+#define I8042_CMD_KBD_TEST	0x01ab
+#define I8042_CMD_KBD_LOOP	0x11d2
+
+#define I8042_CMD_AUX_DISABLE	0x00a7
+#define I8042_CMD_AUX_ENABLE	0x00a8
+#define I8042_CMD_AUX_TEST	0x01a9
+#define I8042_CMD_AUX_SEND	0x10d4
+#define I8042_CMD_AUX_LOOP	0x11d3
+
+#define I8042_CMD_MUX_PFX	0x0090
+#define I8042_CMD_MUX_SEND	0x1090
+
+/*
+ * Status register bits.
+ */
+
+#define I8042_STR_PARITY	0x80
+#define I8042_STR_TIMEOUT	0x40
+#define I8042_STR_AUXDATA	0x20
+#define I8042_STR_KEYLOCK	0x10
+#define I8042_STR_CMDDAT	0x08
+#define I8042_STR_MUXERR	0x04
+#define I8042_STR_IBF		0x02
+#define I8042_STR_OBF		0x01
+
+/*
+ * Control register bits.
+ */
+
+#define I8042_CTR_KBDINT	0x01
+#define I8042_CTR_AUXINT	0x02
+#define I8042_CTR_IGNKEYLOCK	0x08
+#define I8042_CTR_KBDDIS	0x10
+#define I8042_CTR_AUXDIS	0x20
+#define I8042_CTR_XLATE		0x40
+
+struct serio;
+
+#if defined(CONFIG_SERIO_I8042) || defined(CONFIG_SERIO_I8042_MODULE)
+
+void i8042_lock_chip(void);
+void i8042_unlock_chip(void);
+int i8042_command(unsigned char *param, int command);
+int i8042_install_filter(bool (*filter)(unsigned char data, unsigned char str,
+					struct serio *serio));
+int i8042_remove_filter(bool (*filter)(unsigned char data, unsigned char str,
+				       struct serio *serio));
+
+#else
+
+static inline void i8042_lock_chip(void)
+{
+}
+
+static inline void i8042_unlock_chip(void)
+{
+}
+
+static inline int i8042_command(unsigned char *param, int command)
+{
+	return -ENODEV;
+}
+
+static inline int i8042_install_filter(bool (*filter)(unsigned char data, unsigned char str,
+					struct serio *serio))
+{
+	return -ENODEV;
+}
+
+static inline int i8042_remove_filter(bool (*filter)(unsigned char data, unsigned char str,
+				       struct serio *serio))
+{
+	return -ENODEV;
+}
+
+#endif
+
+#endif