xref: /openbmc/linux/include/linux/libps2.h (revision c4c7eac8)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 #ifndef _LIBPS2_H
3 #define _LIBPS2_H
4 
5 /*
6  * Copyright (C) 1999-2002 Vojtech Pavlik
7  * Copyright (C) 2004 Dmitry Torokhov
8  */
9 
10 #include <linux/bitops.h>
11 #include <linux/interrupt.h>
12 #include <linux/mutex.h>
13 #include <linux/types.h>
14 #include <linux/wait.h>
15 
16 struct ps2dev;
17 
18 /**
19  * enum ps2_disposition - indicates how received byte should be handled
20  * @PS2_PROCESS: pass to the main protocol handler, process normally
21  * @PS2_IGNORE: skip the byte
22  * @PS2_ERROR: do not process the byte, abort command in progress
23  */
24 enum ps2_disposition {
25 	PS2_PROCESS,
26 	PS2_IGNORE,
27 	PS2_ERROR,
28 };
29 
30 typedef enum ps2_disposition (*ps2_pre_receive_handler_t)(struct ps2dev *, u8,
31 							  unsigned int);
32 typedef void (*ps2_receive_handler_t)(struct ps2dev *, u8);
33 
34 /**
35  * struct ps2dev - represents a device using PS/2 protocol
36  * @serio: a serio port used by the PS/2 device
37  * @cmd_mutex: a mutex ensuring that only one command is executing at a time
38  * @wait: a waitqueue used to signal completion from the serio interrupt handler
39  * @flags: various internal flags indicating stages of PS/2 command execution
40  * @cmdbuf: buffer holding command response
41  * @cmdcnt: outstanding number of bytes of the command response
42  * @nak: a byte transmitted by the device when it refuses command
43  * @pre_receive_handler: checks communication errors and returns disposition
44  * (&enum ps2_disposition) of the received data byte
45  * @receive_handler: main handler of particular PS/2 protocol, such as keyboard
46  *   or mouse protocol
47  */
48 struct ps2dev {
49 	struct serio *serio;
50 	struct mutex cmd_mutex;
51 	wait_queue_head_t wait;
52 	unsigned long flags;
53 	u8 cmdbuf[8];
54 	u8 cmdcnt;
55 	u8 nak;
56 
57 	ps2_pre_receive_handler_t pre_receive_handler;
58 	ps2_receive_handler_t receive_handler;
59 };
60 
61 void ps2_init(struct ps2dev *ps2dev, struct serio *serio,
62 	      ps2_pre_receive_handler_t pre_receive_handler,
63 	      ps2_receive_handler_t receive_handler);
64 int ps2_sendbyte(struct ps2dev *ps2dev, u8 byte, unsigned int timeout);
65 void ps2_drain(struct ps2dev *ps2dev, size_t maxbytes, unsigned int timeout);
66 void ps2_begin_command(struct ps2dev *ps2dev);
67 void ps2_end_command(struct ps2dev *ps2dev);
68 int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command);
69 int ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command);
70 int ps2_sliced_command(struct ps2dev *ps2dev, u8 command);
71 bool ps2_is_keyboard_id(u8 id);
72 
73 irqreturn_t ps2_interrupt(struct serio *serio, u8 data, unsigned int flags);
74 
75 #endif /* _LIBPS2_H */
76