LXR uboot/include/key

   1/* SPDX-License-Identifier: GPL-2.0+ */
   2/*
   3 * Keyboard matrix helper functions
   4 *
   5 * Copyright (c) 2012 The Chromium OS Authors.
   6 */
   7
   8#ifndef _KEY_MATRIX_H
   9#define _KEY_MATRIX_H
  10
  11#include <common.h>
  12
  13/* Information about a matrix keyboard */
  14struct key_matrix {
  15        /* Dimensions of the keyboard matrix, in rows and columns */
  16        int num_rows;
  17        int num_cols;
  18        int key_count;  /* number of keys in the matrix (= rows * cols) */
  19
  20        /*
  21         * Information about keycode mappings. The plain_keycode array must
  22         * exist but fn may be NULL in which case it is not decoded.
  23         */
  24        const u8 *plain_keycode;        /* key code for each row / column */
  25        const u8 *fn_keycode;           /* ...when Fn held down */
  26        int fn_pos;                     /* position of Fn key in key (or -1) */
  27        int ghost_filter;               /* non-zero to enable ghost filter */
  28};
  29
  30/* Information about a particular key (row, column pair) in the matrix */
  31struct key_matrix_key {
  32        uint8_t row;    /* row number (0 = first) */
  33        uint8_t col;    /* column number (0 = first) */
  34        uint8_t valid;  /* 1 if valid, 0 to ignore this */
  35};
  36
  37/**
  38 * Decode a set of pressed keys into key codes
  39 *
  40 * Given a list of keys that are pressed, this converts this list into
  41 * a list of key codes. Each of the keys has a valid flag, which can be
  42 * used to mark a particular key as invalid (so that it is ignored).
  43 *
  44 * The plain keymap is used, unless the Fn key is detected along the way,
  45 * at which point we switch to the Fn key map.
  46 *
  47 * If key ghosting is detected, we simply ignore the keys and return 0.
  48 *
  49 * @param config        Keyboard matrix config
  50 * @param keys          List of keys to process (each is row, col)
  51 * @param num_keys      Number of keys to process
  52 * @param keycode       Returns a list of key codes, decoded from input
  53 * @param max_keycodes  Size of key codes array (suggest 8)
  54 *
  55 */
  56int key_matrix_decode(struct key_matrix *config, struct key_matrix_key *keys,
  57                      int num_keys, int keycode[], int max_keycodes);
  58
  59/**
  60 * Read the keyboard configuration out of the fdt.
  61 *
  62 * Decode properties of named "linux,<type>keymap" where <type> is either
  63 * empty, or "fn-". Then set up the plain key map (and the FN keymap if
  64 * present).
  65 *
  66 * @param config        Keyboard matrix config
  67 * @param blob          FDT blob
  68 * @param node          Node containing compatible data
  69 * @return 0 if ok, -1 on error
  70 */
  71int key_matrix_decode_fdt(struct udevice *dev, struct key_matrix *config);
  72
  73/**
  74 * Set up a new key matrix.
  75 *
  76 * @param config        Keyboard matrix config
  77 * @param rows          Number of rows in key matrix
  78 * @param cols          Number of columns in key matrix
  79 * @param ghost_filter  Non-zero to enable ghost filtering
  80 * @return 0 if ok, -1 on error
  81 */
  82int key_matrix_init(struct key_matrix *config, int rows, int cols,
  83                    int ghost_filter);
  84
  85#endif
  86