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