xref: /openbmc/u-boot/include/input.h (revision 3fda0262)
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