1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Helpers for matrix keyboard bindings 4 * 5 * Copyright (C) 2012 Google, Inc 6 * 7 * Author: 8 * Olof Johansson <olof@lixom.net> 9 */ 10 11 #include <linux/device.h> 12 #include <linux/export.h> 13 #include <linux/gfp.h> 14 #include <linux/input.h> 15 #include <linux/input/matrix_keypad.h> 16 #include <linux/kernel.h> 17 #include <linux/module.h> 18 #include <linux/property.h> 19 #include <linux/slab.h> 20 #include <linux/types.h> 21 22 static bool matrix_keypad_map_key(struct input_dev *input_dev, 23 unsigned int rows, unsigned int cols, 24 unsigned int row_shift, unsigned int key) 25 { 26 unsigned short *keymap = input_dev->keycode; 27 unsigned int row = KEY_ROW(key); 28 unsigned int col = KEY_COL(key); 29 unsigned short code = KEY_VAL(key); 30 31 if (row >= rows || col >= cols) { 32 dev_err(input_dev->dev.parent, 33 "%s: invalid keymap entry 0x%x (row: %d, col: %d, rows: %d, cols: %d)\n", 34 __func__, key, row, col, rows, cols); 35 return false; 36 } 37 38 keymap[MATRIX_SCAN_CODE(row, col, row_shift)] = code; 39 __set_bit(code, input_dev->keybit); 40 41 return true; 42 } 43 44 /** 45 * matrix_keypad_parse_properties() - Read properties of matrix keypad 46 * 47 * @dev: Device containing properties 48 * @rows: Returns number of matrix rows 49 * @cols: Returns number of matrix columns 50 * @return 0 if OK, <0 on error 51 */ 52 int matrix_keypad_parse_properties(struct device *dev, 53 unsigned int *rows, unsigned int *cols) 54 { 55 *rows = *cols = 0; 56 57 device_property_read_u32(dev, "keypad,num-rows", rows); 58 device_property_read_u32(dev, "keypad,num-columns", cols); 59 60 if (!*rows || !*cols) { 61 dev_err(dev, "number of keypad rows/columns not specified\n"); 62 return -EINVAL; 63 } 64 65 return 0; 66 } 67 EXPORT_SYMBOL_GPL(matrix_keypad_parse_properties); 68 69 static int matrix_keypad_parse_keymap(const char *propname, 70 unsigned int rows, unsigned int cols, 71 struct input_dev *input_dev) 72 { 73 struct device *dev = input_dev->dev.parent; 74 unsigned int row_shift = get_count_order(cols); 75 unsigned int max_keys = rows << row_shift; 76 u32 *keys; 77 int i; 78 int size; 79 int retval; 80 81 if (!propname) 82 propname = "linux,keymap"; 83 84 size = device_property_read_u32_array(dev, propname, NULL, 0); 85 if (size <= 0) { 86 dev_err(dev, "missing or malformed property %s: %d\n", 87 propname, size); 88 return size < 0 ? size : -EINVAL; 89 } 90 91 if (size > max_keys) { 92 dev_err(dev, "%s size overflow (%d vs max %u)\n", 93 propname, size, max_keys); 94 return -EINVAL; 95 } 96 97 keys = kmalloc_array(size, sizeof(u32), GFP_KERNEL); 98 if (!keys) 99 return -ENOMEM; 100 101 retval = device_property_read_u32_array(dev, propname, keys, size); 102 if (retval) { 103 dev_err(dev, "failed to read %s property: %d\n", 104 propname, retval); 105 goto out; 106 } 107 108 for (i = 0; i < size; i++) { 109 if (!matrix_keypad_map_key(input_dev, rows, cols, 110 row_shift, keys[i])) { 111 retval = -EINVAL; 112 goto out; 113 } 114 } 115 116 retval = 0; 117 118 out: 119 kfree(keys); 120 return retval; 121 } 122 123 /** 124 * matrix_keypad_build_keymap - convert platform keymap into matrix keymap 125 * @keymap_data: keymap supplied by the platform code 126 * @keymap_name: name of device tree property containing keymap (if device 127 * tree support is enabled). 128 * @rows: number of rows in target keymap array 129 * @cols: number of cols in target keymap array 130 * @keymap: expanded version of keymap that is suitable for use by 131 * matrix keyboard driver 132 * @input_dev: input devices for which we are setting up the keymap 133 * 134 * This function converts platform keymap (encoded with KEY() macro) into 135 * an array of keycodes that is suitable for using in a standard matrix 136 * keyboard driver that uses row and col as indices. 137 * 138 * If @keymap_data is not supplied and device tree support is enabled 139 * it will attempt load the keymap from property specified by @keymap_name 140 * argument (or "linux,keymap" if @keymap_name is %NULL). 141 * 142 * If @keymap is %NULL the function will automatically allocate managed 143 * block of memory to store the keymap. This memory will be associated with 144 * the parent device and automatically freed when device unbinds from the 145 * driver. 146 * 147 * Callers are expected to set up input_dev->dev.parent before calling this 148 * function. 149 */ 150 int matrix_keypad_build_keymap(const struct matrix_keymap_data *keymap_data, 151 const char *keymap_name, 152 unsigned int rows, unsigned int cols, 153 unsigned short *keymap, 154 struct input_dev *input_dev) 155 { 156 unsigned int row_shift = get_count_order(cols); 157 size_t max_keys = rows << row_shift; 158 int i; 159 int error; 160 161 if (WARN_ON(!input_dev->dev.parent)) 162 return -EINVAL; 163 164 if (!keymap) { 165 keymap = devm_kcalloc(input_dev->dev.parent, 166 max_keys, sizeof(*keymap), 167 GFP_KERNEL); 168 if (!keymap) { 169 dev_err(input_dev->dev.parent, 170 "Unable to allocate memory for keymap"); 171 return -ENOMEM; 172 } 173 } 174 175 input_dev->keycode = keymap; 176 input_dev->keycodesize = sizeof(*keymap); 177 input_dev->keycodemax = max_keys; 178 179 __set_bit(EV_KEY, input_dev->evbit); 180 181 if (keymap_data) { 182 for (i = 0; i < keymap_data->keymap_size; i++) { 183 unsigned int key = keymap_data->keymap[i]; 184 185 if (!matrix_keypad_map_key(input_dev, rows, cols, 186 row_shift, key)) 187 return -EINVAL; 188 } 189 } else { 190 error = matrix_keypad_parse_keymap(keymap_name, rows, cols, 191 input_dev); 192 if (error) 193 return error; 194 } 195 196 __clear_bit(KEY_RESERVED, input_dev->keybit); 197 198 return 0; 199 } 200 EXPORT_SYMBOL(matrix_keypad_build_keymap); 201 202 MODULE_LICENSE("GPL"); 203