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/gfp.h>
  22 #include <linux/kernel.h>
  23 #include <linux/types.h>
  24 #include <linux/input.h>
  25 #include <linux/of.h>
  26 #include <linux/export.h>
  27 #include <linux/module.h>
  28 #include <linux/input/matrix_keypad.h>
  29
  30 static bool matrix_keypad_map_key(struct input_dev *input_dev,
  31                                   unsigned int rows, unsigned int cols,
  32                                   unsigned int row_shift, unsigned int key)
  33 {
  34         unsigned short *keymap = input_dev->keycode;
  35         unsigned int row = KEY_ROW(key);
  36         unsigned int col = KEY_COL(key);
  37         unsigned short code = KEY_VAL(key);
  38
  39         if (row >= rows || col >= cols) {
  40                 dev_err(input_dev->dev.parent,
  41                         "%s: invalid keymap entry 0x%x (row: %d, col: %d, rows: %d, cols: %d)\n",
  42                         __func__, key, row, col, rows, cols);
  43                 return false;
  44         }
  45
  46         keymap[MATRIX_SCAN_CODE(row, col, row_shift)] = code;
  47         __set_bit(code, input_dev->keybit);
  48
  49         return true;
  50 }
  51
  52 #ifdef CONFIG_OF
  53 int matrix_keypad_parse_of_params(struct device *dev,
  54                                   unsigned int *rows, unsigned int *cols)
  55 {
  56         struct device_node *np = dev->of_node;
  57
  58         if (!np) {
  59                 dev_err(dev, "missing DT data");
  60                 return -EINVAL;
  61         }
  62         of_property_read_u32(np, "keypad,num-rows", rows);
  63         of_property_read_u32(np, "keypad,num-columns", cols);
  64         if (!*rows || !*cols) {
  65                 dev_err(dev, "number of keypad rows/columns not specified\n");
  66                 return -EINVAL;
  67         }
  68
  69         return 0;
  70 }
  71 EXPORT_SYMBOL_GPL(matrix_keypad_parse_of_params);
  72
  73 static int matrix_keypad_parse_of_keymap(const char *propname,
  74                                          unsigned int rows, unsigned int cols,
  75                                          struct input_dev *input_dev)
  76 {
  77         struct device *dev = input_dev->dev.parent;
  78         struct device_node *np = dev->of_node;
  79         unsigned int row_shift = get_count_order(cols);
  80         unsigned int max_keys = rows << row_shift;
  81         unsigned int proplen, i, size;
  82         const __be32 *prop;
  83
  84         if (!np)
  85                 return -ENOENT;
  86
  87         if (!propname)
  88                 propname = "linux,keymap";
  89
  90         prop = of_get_property(np, propname, &proplen);
  91         if (!prop) {
  92                 dev_err(dev, "OF: %s property not defined in %s\n",
  93                         propname, np->full_name);
  94                 return -ENOENT;
  95         }
  96
  97         if (proplen % sizeof(u32)) {
  98                 dev_err(dev, "OF: Malformed keycode property %s in %s\n",
  99                         propname, np->full_name);
 100                 return -EINVAL;
 101         }
 102
 103         size = proplen / sizeof(u32);
 104         if (size > max_keys) {
 105                 dev_err(dev, "OF: %s size overflow\n", propname);
 106                 return -EINVAL;
 107         }
 108
 109         for (i = 0; i < size; i++) {
 110                 unsigned int key = be32_to_cpup(prop + i);
 111
 112                 if (!matrix_keypad_map_key(input_dev, rows, cols,
 113                                            row_shift, key))
 114                         return -EINVAL;
 115         }
 116
 117         return 0;
 118 }
 119 #else
 120 static int matrix_keypad_parse_of_keymap(const char *propname,
 121                                          unsigned int rows, unsigned int cols,
 122                                          struct input_dev *input_dev)
 123 {
 124         return -ENOSYS;
 125 }
 126 #endif
 127
 128 /**
 129  * matrix_keypad_build_keymap - convert platform keymap into matrix keymap
 130  * @keymap_data: keymap supplied by the platform code
 131  * @keymap_name: name of device tree property containing keymap (if device
 132  *      tree support is enabled).
 133  * @rows: number of rows in target keymap array
 134  * @cols: number of cols in target keymap array
 135  * @keymap: expanded version of keymap that is suitable for use by
 136  * matrix keyboard driver
 137  * @input_dev: input devices for which we are setting up the keymap
 138  *
 139  * This function converts platform keymap (encoded with KEY() macro) into
 140  * an array of keycodes that is suitable for using in a standard matrix
 141  * keyboard driver that uses row and col as indices.
 142  *
 143  * If @keymap_data is not supplied and device tree support is enabled
 144  * it will attempt load the keymap from property specified by @keymap_name
 145  * argument (or "linux,keymap" if @keymap_name is %NULL).
 146  *
 147  * If @keymap is %NULL the function will automatically allocate managed
 148  * block of memory to store the keymap. This memory will be associated with
 149  * the parent device and automatically freed when device unbinds from the
 150  * driver.
 151  *
 152  * Callers are expected to set up input_dev->dev.parent before calling this
 153  * function.
 154  */
 155 int matrix_keypad_build_keymap(const struct matrix_keymap_data *keymap_data,
 156                                const char *keymap_name,
 157                                unsigned int rows, unsigned int cols,
 158                                unsigned short *keymap,
 159                                struct input_dev *input_dev)
 160 {
 161         unsigned int row_shift = get_count_order(cols);
 162         size_t max_keys = rows << row_shift;
 163         int i;
 164         int error;
 165
 166         if (WARN_ON(!input_dev->dev.parent))
 167                 return -EINVAL;
 168
 169         if (!keymap) {
 170                 keymap = devm_kzalloc(input_dev->dev.parent,
 171                                       max_keys * sizeof(*keymap),
 172                                       GFP_KERNEL);
 173                 if (!keymap) {
 174                         dev_err(input_dev->dev.parent,
 175                                 "Unable to allocate memory for keymap");
 176                         return -ENOMEM;
 177                 }
 178         }
 179
 180         input_dev->keycode = keymap;
 181         input_dev->keycodesize = sizeof(*keymap);
 182         input_dev->keycodemax = max_keys;
 183
 184         __set_bit(EV_KEY, input_dev->evbit);
 185
 186         if (keymap_data) {
 187                 for (i = 0; i < keymap_data->keymap_size; i++) {
 188                         unsigned int key = keymap_data->keymap[i];
 189
 190                         if (!matrix_keypad_map_key(input_dev, rows, cols,
 191                                                    row_shift, key))
 192                                 return -EINVAL;
 193                 }
 194         } else {
 195                 error = matrix_keypad_parse_of_keymap(keymap_name, rows, cols,
 196                                                       input_dev);
 197                 if (error)
 198                         return error;
 199         }
 200
 201         __clear_bit(KEY_RESERVED, input_dev->keybit);
 202
 203         return 0;
 204 }
 205 EXPORT_SYMBOL(matrix_keypad_build_keymap);
 206
 207 MODULE_LICENSE("GPL");