1 files changed, 75 insertions, 0 deletions
diff --git a/include/linux/libps2.h b/include/linux/libps2.h
new file mode 100644
index 000000000..9ca9ce4e6
--- /dev/null
+++ b/include/linux/libps2.h
@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _LIBPS2_H
+#define _LIBPS2_H
+
+/*
+ * Copyright (C) 1999-2002 Vojtech Pavlik
+ * Copyright (C) 2004 Dmitry Torokhov
+ */
+
+#include <linux/bitops.h>
+#include <linux/interrupt.h>
+#include <linux/mutex.h>
+#include <linux/types.h>
+#include <linux/wait.h>
+
+struct ps2dev;
+
+/**
+ * enum ps2_disposition - indicates how received byte should be handled
+ * @PS2_PROCESS: pass to the main protocol handler, process normally
+ * @PS2_IGNORE: skip the byte
+ * @PS2_ERROR: do not process the byte, abort command in progress
+ */
+enum ps2_disposition {
+	PS2_PROCESS,
+	PS2_IGNORE,
+	PS2_ERROR,
+};
+
+typedef enum ps2_disposition (*ps2_pre_receive_handler_t)(struct ps2dev *, u8,
+							  unsigned int);
+typedef void (*ps2_receive_handler_t)(struct ps2dev *, u8);
+
+/**
+ * struct ps2dev - represents a device using PS/2 protocol
+ * @serio: a serio port used by the PS/2 device
+ * @cmd_mutex: a mutex ensuring that only one command is executing at a time
+ * @wait: a waitqueue used to signal completion from the serio interrupt handler
+ * @flags: various internal flags indicating stages of PS/2 command execution
+ * @cmdbuf: buffer holding command response
+ * @cmdcnt: outstanding number of bytes of the command response
+ * @nak: a byte transmitted by the device when it refuses command
+ * @pre_receive_handler: checks communication errors and returns disposition
+ * (&enum ps2_disposition) of the received data byte
+ * @receive_handler: main handler of particular PS/2 protocol, such as keyboard
+ *   or mouse protocol
+ */
+struct ps2dev {
+	struct serio *serio;
+	struct mutex cmd_mutex;
+	wait_queue_head_t wait;
+	unsigned long flags;
+	u8 cmdbuf[8];
+	u8 cmdcnt;
+	u8 nak;
+
+	ps2_pre_receive_handler_t pre_receive_handler;
+	ps2_receive_handler_t receive_handler;
+};
+
+void ps2_init(struct ps2dev *ps2dev, struct serio *serio,
+	      ps2_pre_receive_handler_t pre_receive_handler,
+	      ps2_receive_handler_t receive_handler);
+int ps2_sendbyte(struct ps2dev *ps2dev, u8 byte, unsigned int timeout);
+void ps2_drain(struct ps2dev *ps2dev, size_t maxbytes, unsigned int timeout);
+void ps2_begin_command(struct ps2dev *ps2dev);
+void ps2_end_command(struct ps2dev *ps2dev);
+int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command);
+int ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command);
+int ps2_sliced_command(struct ps2dev *ps2dev, u8 command);
+bool ps2_is_keyboard_id(u8 id);
+
+irqreturn_t ps2_interrupt(struct serio *serio, u8 data, unsigned int flags);
+
+#endif /* _LIBPS2_H */