xref: /openbmc/u-boot/include/input.h (revision 85ab0452)
1 /*
2  * Keyboard input helper functions (too small to be called a layer)
3  *
4  * Copyright (c) 2011 The Chromium OS Authors.
5  *
6  * SPDX-License-Identifier:	GPL-2.0+
7  */
8 
9 #ifndef _INPUT_H
10 #define _INPUT_H
11 
12 enum {
13 	INPUT_MAX_MODIFIERS	= 4,
14 	INPUT_BUFFER_LEN	= 16,
15 };
16 
17 enum {
18 	/* Keyboard LEDs */
19 	INPUT_LED_SCROLL	= 1 << 0,
20 	INPUT_LED_NUM		= 1 << 1,
21 	INPUT_LED_CAPS		= 1 << 2,
22 };
23 
24 /*
25  * This table translates key codes to ASCII. Most of the entries are ASCII
26  * codes, but entries after KEY_FIRST_MOD indicate that this key is a
27  * modifier key, like shift, ctrl. KEY_FIRST_MOD + MOD_SHIFT is the shift
28  * key, for example.
29  */
30 struct input_key_xlate {
31 	/* keycode of the modifiers which select this table, -1 if none */
32 	int left_keycode;
33 	int right_keycode;
34 	const uchar *xlate;	/* keycode to ASCII table */
35 	int num_entries;	/* number of entries in this table */
36 };
37 
38 struct input_config {
39 	struct udevice *dev;
40 	uchar fifo[INPUT_BUFFER_LEN];
41 	int fifo_in, fifo_out;
42 
43 	/* Which modifiers are active (1 bit for each MOD_... value) */
44 	uchar modifiers;
45 	uchar flags;		/* active state keys (FLAGS_...) */
46 	uchar leds;		/* active LEDs (INPUT_LED_...) */
47 	uchar leds_changed;	/* LEDs that just changed */
48 	uchar num_tables;	/* number of modifier tables */
49 	int prev_keycodes[INPUT_BUFFER_LEN];	/* keys held last time */
50 	int num_prev_keycodes;	/* number of prev keys */
51 	struct input_key_xlate table[INPUT_MAX_MODIFIERS];
52 
53 	/**
54 	 * Function the input helper calls to scan the keyboard
55 	 *
56 	 * @param config	Input state
57 	 * @return 0 if no keys read, otherwise number of keys read, or 1 if
58 	 *		unknown
59 	 */
60 	int (*read_keys)(struct input_config *config);
61 	bool allow_repeats;		/* Don't filter out repeats */
62 	unsigned int next_repeat_ms;	/* Next time we repeat a key */
63 	unsigned int repeat_delay_ms;	/* Time before autorepeat starts */
64 	unsigned int repeat_rate_ms;	/* Autorepeat rate in ms */
65 };
66 
67 struct stdio_dev;
68 
69 /**
70  * Convert a list of key codes into ASCII and send them
71  *
72  * @param config	Input state
73  * @param keycode	List of key codes to examine
74  * @param num_keycodes	Number of key codes
75  * @return number of ascii characters sent, or 0 if none, or -1 for an
76  *	internal error
77  */
78 int input_send_keycodes(struct input_config *config, int keycode[], int count);
79 
80 /**
81  * Add a new keycode to an existing list of keycodes
82  *
83  * This can be used to handle keyboards which do their own scanning. An
84  * internal list of depressed keys is maintained by the input library. Then
85  * this function is called to add a new key to the list (when a 'make code' is
86  * received), or remove a key (when a 'break code' is received).
87  *
88  * This function looks after maintenance of the list of active keys, and calls
89  * input_send_keycodes() with its updated list.
90  *
91  * @param config	Input state
92  * @param new_keycode	New keycode to add/remove
93  * @param release	true if this key was released, false if depressed
94  * @return number of ascii characters sent, or 0 if none, or -1 for an
95  *	internal error
96  */
97 int input_add_keycode(struct input_config *config, int new_keycode,
98 		      bool release);
99 
100 /**
101  * Add a new key translation table to the input
102  *
103  * @param config	Input state
104  * @param left_keycode	Key to hold to get into this table
105  * @param right_keycode	Another key to hold to get into this table
106  * @param xlate		Conversion table from key codes to ASCII
107  * @param num_entries	Number of entries in xlate table
108  */
109 int input_add_table(struct input_config *config, int left_keycode,
110 		    int right_keycode, const uchar *xlate, int num_entries);
111 
112 /**
113  * Test if keys are available to be read
114  *
115  * @param config	Input state
116  * @return 0 if no keys available, 1 if keys are available
117  */
118 int input_tstc(struct input_config *config);
119 
120 /**
121  * Read a key
122  *
123  * TODO: U-Boot wants 0 for no key, but Ctrl-@ is a valid key...
124  *
125  * @param config	Input state
126  * @return key, or 0 if no key, or -1 if error
127  */
128 int input_getc(struct input_config *config);
129 
130 /**
131  * Register a new device with stdio and switch to it if wanted
132  *
133  * @param dev	Pointer to device
134  * @return 0 if ok, -1 on error
135  */
136 int input_stdio_register(struct stdio_dev *dev);
137 
138 /**
139  * Set up the keyboard autorepeat delays
140  *
141  * @param repeat_delay_ms	Delay before key auto-repeat starts (in ms)
142  * @param repeat_rate_ms	Delay between successive key repeats (in ms)
143  */
144 void input_set_delays(struct input_config *config, int repeat_delay_ms,
145 	       int repeat_rate_ms);
146 
147 /**
148  * Tell the input layer whether to allow the caller to determine repeats
149  *
150  * Generally the input library handles processing of a list of scanned keys.
151  * Repeated keys need to be generated based on a timer in this case, since all
152  * that is provided is a list of keys current depressed.
153  *
154  * Keyboards which do their own scanning will resend codes when they want to
155  * inject a repeating key. This function can be called at start-up to select
156  * this behaviour.
157  *
158  * @param config	Input state
159  * @param allow_repeats	true to repeat depressed keys every time
160  *			input_send_keycodes() is called, false to do normal
161  *			keyboard repeat processing with a timer.
162  */
163 void input_allow_repeats(struct input_config *config, bool allow_repeats);
164 
165 /**
166  * Check if keyboard LEDs need to be updated
167  *
168  * This can be called after input_tstc() to see if keyboard LEDs need
169  * updating.
170  *
171  * @param config	Input state
172  * @return -1 if no LEDs need updating, other value if they do
173  */
174 int input_leds_changed(struct input_config *config);
175 
176 /**
177  * Set up the key map tables
178  *
179  * This must be called after input_init() or keycode decoding will not work.
180  *
181  * @param config	Input state
182  * @param german	true to use German keyboard layout, false for US
183  * @return 0 if ok, -1 on error
184  */
185 int input_add_tables(struct input_config *config, bool german);
186 
187 /**
188  * Set up the input handler with basic key maps.
189  *
190  * @param config	Input state
191  * @param leds		Initial LED value (INPUT_LED_ mask), 0 suggested
192  * @return 0 if ok, -1 on error
193  */
194 int input_init(struct input_config *config, int leds);
195 
196 #ifdef CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
197 extern int overwrite_console(void);
198 #define OVERWRITE_CONSOLE overwrite_console()
199 #else
200 #define OVERWRITE_CONSOLE 0
201 #endif /* CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE */
202 
203 #endif
204