include/input.h

   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_CAPS          = 1 << 1,
  21         INPUT_LED_NUM           = 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 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  * Set up the key map tables
 166  *
 167  * This must be called after input_init() or keycode decoding will not work.
 168  *
 169  * @param config        Input state
 170  * @return 0 if ok, -1 on error
 171  */
 172 int input_add_tables(struct input_config *config);
 173
 174 /**
 175  * Set up the input handler with basic key maps.
 176  *
 177  * @param config        Input state
 178  * @param leds          Initial LED value (INPUT_LED_ mask), 0 suggested
 179  * @return 0 if ok, -1 on error
 180  */
 181 int input_init(struct input_config *config, int leds);
 182
 183 #ifdef CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
 184 extern int overwrite_console(void);
 185 #define OVERWRITE_CONSOLE overwrite_console()
 186 #else
 187 #define OVERWRITE_CONSOLE 0
 188 #endif /* CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE */
 189
 190 #endif