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"); 208