drivers/input/matrix-keymap.c

   1 /*
   2  * Helpers for matrix keyboard bindings
   3  *
   4  * Copyright (C) 2012 Google, Inc
   5  *
   6  * Author:
   7  *      Olof Johansson <olof@lixom.net>
   8  *
   9  * This software is licensed under the terms of the GNU General Public
  10  * License version 2, as published by the Free Software Foundation, and
  11  * may be copied, distributed, and modified under those terms.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  */
  19
  20 #include <linux/device.h>
  21 #include <linux/kernel.h>
  22 #include <linux/types.h>
  23 #include <linux/input.h>
  24 #include <linux/of.h>
  25 #include <linux/export.h>
  26 #include <linux/module.h>
  27 #include <linux/input/matrix_keypad.h>
  28
  29 static bool matrix_keypad_map_key(struct input_dev *input_dev,
  30                                   unsigned int rows, unsigned int cols,
  31                                   unsigned int row_shift, unsigned int key)
  32 {
  33         unsigned short *keymap = input_dev->keycode;
  34         unsigned int row = KEY_ROW(key);
  35         unsigned int col = KEY_COL(key);
  36         unsigned short code = KEY_VAL(key);
  37
  38         if (row >= rows || col >= cols) {
  39                 dev_err(input_dev->dev.parent,
  40                         "%s: invalid keymap entry 0x%x (row: %d, col: %d, rows: %d, cols: %d)\n",
  41                         __func__, key, row, col, rows, cols);
  42                 return false;
  43         }
  44
  45         keymap[MATRIX_SCAN_CODE(row, col, row_shift)] = code;
  46         __set_bit(code, input_dev->keybit);
  47
  48         return true;
  49 }
  50
  51 #ifdef CONFIG_OF
  52 static int matrix_keypad_parse_of_keymap(const char *propname,
  53                                          unsigned int rows, unsigned int cols,
  54                                          struct input_dev *input_dev)
  55 {
  56         struct device *dev = input_dev->dev.parent;
  57         struct device_node *np = dev->of_node;
  58         unsigned int row_shift = get_count_order(cols);
  59         unsigned int max_keys = rows << row_shift;
  60         unsigned int proplen, i, size;
  61         const __be32 *prop;
  62
  63         if (!np)
  64                 return -ENOENT;
  65
  66         if (!propname)
  67                 propname = "linux,keymap";
  68
  69         prop = of_get_property(np, propname, &proplen);
  70         if (!prop) {
  71                 dev_err(dev, "OF: %s property not defined in %s\n",
  72                         propname, np->full_name);
  73                 return -ENOENT;
  74         }
  75
  76         if (proplen % sizeof(u32)) {
  77                 dev_err(dev, "OF: Malformed keycode property %s in %s\n",
  78                         propname, np->full_name);
  79                 return -EINVAL;
  80         }
  81
  82         size = proplen / sizeof(u32);
  83         if (size > max_keys) {
  84                 dev_err(dev, "OF: %s size overflow\n", propname);
  85                 return -EINVAL;
  86         }
  87
  88         for (i = 0; i < size; i++) {
  89                 unsigned int key = be32_to_cpup(prop + i);
  90
  91                 if (!matrix_keypad_map_key(input_dev, rows, cols,
  92                                            row_shift, key))
  93                         return -EINVAL;
  94         }
  95
  96         return 0;
  97 }
  98 #else
  99 static int matrix_keypad_parse_of_keymap(const char *propname,
 100                                          unsigned int rows, unsigned int cols,
 101                                          struct input_dev *input_dev)
 102 {
 103         return -ENOSYS;
 104 }
 105 #endif
 106
 107 /**
 108  * matrix_keypad_build_keymap - convert platform keymap into matrix keymap
 109  * @keymap_data: keymap supplied by the platform code
 110  * @keymap_name: name of device tree property containing keymap (if device
 111  *      tree support is enabled).
 112  * @rows: number of rows in target keymap array
 113  * @cols: number of cols in target keymap array
 114  * @keymap: expanded version of keymap that is suitable for use by
 115  * matrix keyboard driver
 116  * @input_dev: input devices for which we are setting up the keymap
 117  *
 118  * This function converts platform keymap (encoded with KEY() macro) into
 119  * an array of keycodes that is suitable for using in a standard matrix
 120  * keyboard driver that uses row and col as indices.
 121  *
 122  * If @keymap_data is not supplied and device tree support is enabled
 123  * it will attempt load the keymap from property specified by @keymap_name
 124  * argument (or "linux,keymap" if @keymap_name is %NULL).
 125  *
 126  * Callers are expected to set up input_dev->dev.parent before calling this
 127  * function.
 128  */
 129 int matrix_keypad_build_keymap(const struct matrix_keymap_data *keymap_data,
 130                                const char *keymap_name,
 131                                unsigned int rows, unsigned int cols,
 132                                unsigned short *keymap,
 133                                struct input_dev *input_dev)
 134 {
 135         unsigned int row_shift = get_count_order(cols);
 136         int i;
 137         int error;
 138
 139         input_dev->keycode = keymap;
 140         input_dev->keycodesize = sizeof(*keymap);
 141         input_dev->keycodemax = rows << row_shift;
 142
 143         __set_bit(EV_KEY, input_dev->evbit);
 144
 145         if (keymap_data) {
 146                 for (i = 0; i < keymap_data->keymap_size; i++) {
 147                         unsigned int key = keymap_data->keymap[i];
 148
 149                         if (!matrix_keypad_map_key(input_dev, rows, cols,
 150                                                    row_shift, key))
 151                                 return -EINVAL;
 152                 }
 153         } else {
 154                 error = matrix_keypad_parse_of_keymap(keymap_name, rows, cols,
 155                                                       input_dev);
 156                 if (error)
 157                         return error;
 158         }
 159
 160         __clear_bit(KEY_RESERVED, input_dev->keybit);
 161
 162         return 0;
 163 }
 164 EXPORT_SYMBOL(matrix_keypad_build_keymap);
 165
 166 MODULE_LICENSE("GPL");