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 #include <linux/device.h> 20 #include <linux/export.h> 21 #include <linux/gfp.h> 22 #include <linux/input.h> 23 #include <linux/input/matrix_keypad.h> 24 #include <linux/kernel.h> 25 #include <linux/module.h> 26 #include <linux/property.h> 27 #include <linux/slab.h> 28 #include <linux/types.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 /** 53 * matrix_keypad_parse_properties() - Read properties of matrix keypad 54 * 55 * @dev: Device containing properties 56 * @rows: Returns number of matrix rows 57 * @cols: Returns number of matrix columns 58 * @return 0 if OK, <0 on error 59 */ 60 int matrix_keypad_parse_properties(struct device *dev, 61 unsigned int *rows, unsigned int *cols) 62 { 63 *rows = *cols = 0; 64 65 device_property_read_u32(dev, "keypad,num-rows", rows); 66 device_property_read_u32(dev, "keypad,num-columns", cols); 67 68 if (!*rows || !*cols) { 69 dev_err(dev, "number of keypad rows/columns not specified\n"); 70 return -EINVAL; 71 } 72 73 return 0; 74 } 75 EXPORT_SYMBOL_GPL(matrix_keypad_parse_properties); 76 77 static int matrix_keypad_parse_keymap(const char *propname, 78 unsigned int rows, unsigned int cols, 79 struct input_dev *input_dev) 80 { 81 struct device *dev = input_dev->dev.parent; 82 unsigned int row_shift = get_count_order(cols); 83 unsigned int max_keys = rows << row_shift; 84 u32 *keys; 85 int i; 86 int size; 87 int retval; 88 89 if (!propname) 90 propname = "linux,keymap"; 91 92 size = device_property_read_u32_array(dev, propname, NULL, 0); 93 if (size <= 0) { 94 dev_err(dev, "missing or malformed property %s: %d\n", 95 propname, size); 96 return size < 0 ? size : -EINVAL; 97 } 98 99 if (size > max_keys) { 100 dev_err(dev, "%s size overflow (%d vs max %u)\n", 101 propname, size, max_keys); 102 return -EINVAL; 103 } 104 105 keys = kmalloc_array(size, sizeof(u32), GFP_KERNEL); 106 if (!keys) 107 return -ENOMEM; 108 109 retval = device_property_read_u32_array(dev, propname, keys, size); 110 if (retval) { 111 dev_err(dev, "failed to read %s property: %d\n", 112 propname, retval); 113 goto out; 114 } 115 116 for (i = 0; i < size; i++) { 117 if (!matrix_keypad_map_key(input_dev, rows, cols, 118 row_shift, keys[i])) { 119 retval = -EINVAL; 120 goto out; 121 } 122 } 123 124 retval = 0; 125 126 out: 127 kfree(keys); 128 return retval; 129 } 130 131 /** 132 * matrix_keypad_build_keymap - convert platform keymap into matrix keymap 133 * @keymap_data: keymap supplied by the platform code 134 * @keymap_name: name of device tree property containing keymap (if device 135 * tree support is enabled). 136 * @rows: number of rows in target keymap array 137 * @cols: number of cols in target keymap array 138 * @keymap: expanded version of keymap that is suitable for use by 139 * matrix keyboard driver 140 * @input_dev: input devices for which we are setting up the keymap 141 * 142 * This function converts platform keymap (encoded with KEY() macro) into 143 * an array of keycodes that is suitable for using in a standard matrix 144 * keyboard driver that uses row and col as indices. 145 * 146 * If @keymap_data is not supplied and device tree support is enabled 147 * it will attempt load the keymap from property specified by @keymap_name 148 * argument (or "linux,keymap" if @keymap_name is %NULL). 149 * 150 * If @keymap is %NULL the function will automatically allocate managed 151 * block of memory to store the keymap. This memory will be associated with 152 * the parent device and automatically freed when device unbinds from the 153 * driver. 154 * 155 * Callers are expected to set up input_dev->dev.parent before calling this 156 * function. 157 */ 158 int matrix_keypad_build_keymap(const struct matrix_keymap_data *keymap_data, 159 const char *keymap_name, 160 unsigned int rows, unsigned int cols, 161 unsigned short *keymap, 162 struct input_dev *input_dev) 163 { 164 unsigned int row_shift = get_count_order(cols); 165 size_t max_keys = rows << row_shift; 166 int i; 167 int error; 168 169 if (WARN_ON(!input_dev->dev.parent)) 170 return -EINVAL; 171 172 if (!keymap) { 173 keymap = devm_kzalloc(input_dev->dev.parent, 174 max_keys * sizeof(*keymap), 175 GFP_KERNEL); 176 if (!keymap) { 177 dev_err(input_dev->dev.parent, 178 "Unable to allocate memory for keymap"); 179 return -ENOMEM; 180 } 181 } 182 183 input_dev->keycode = keymap; 184 input_dev->keycodesize = sizeof(*keymap); 185 input_dev->keycodemax = max_keys; 186 187 __set_bit(EV_KEY, input_dev->evbit); 188 189 if (keymap_data) { 190 for (i = 0; i < keymap_data->keymap_size; i++) { 191 unsigned int key = keymap_data->keymap[i]; 192 193 if (!matrix_keypad_map_key(input_dev, rows, cols, 194 row_shift, key)) 195 return -EINVAL; 196 } 197 } else { 198 error = matrix_keypad_parse_keymap(keymap_name, rows, cols, 199 input_dev); 200 if (error) 201 return error; 202 } 203 204 __clear_bit(KEY_RESERVED, input_dev->keybit); 205 206 return 0; 207 } 208 EXPORT_SYMBOL(matrix_keypad_build_keymap); 209 210 MODULE_LICENSE("GPL"); 211