/* * Helpers for matrix keyboard bindings * * Copyright (C) 2012 Google, Inc * * Author: * Olof Johansson <olof@lixom.net> * * This software is licensed under the terms of the GNU General Public * License version 2, as published by the Free Software Foundation, and * may be copied, distributed, and modified under those terms. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include <linux/device.h> #include <linux/export.h> #include <linux/gfp.h> #include <linux/input.h> #include <linux/input/matrix_keypad.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/property.h> #include <linux/slab.h> #include <linux/types.h> static bool matrix_keypad_map_key(struct input_dev *input_dev, unsigned int rows, unsigned int cols, unsigned int row_shift, unsigned int key) { unsigned short *keymap = input_dev->keycode; unsigned int row = KEY_ROW(key); unsigned int col = KEY_COL(key); unsigned short code = KEY_VAL(key); if (row >= rows || col >= cols) { dev_err(input_dev->dev.parent, "%s: invalid keymap entry 0x%x (row: %d, col: %d, rows: %d, cols: %d)\n", __func__, key, row, col, rows, cols); return false; } keymap[MATRIX_SCAN_CODE(row, col, row_shift)] = code; __set_bit(code, input_dev->keybit); return true; } /** * matrix_keypad_parse_properties() - Read properties of matrix keypad * * @dev: Device containing properties * @rows: Returns number of matrix rows * @cols: Returns number of matrix columns * @return 0 if OK, <0 on error */ int matrix_keypad_parse_properties(struct device *dev, unsigned int *rows, unsigned int *cols) { *rows = *cols = 0; device_property_read_u32(dev, "keypad,num-rows", rows); device_property_read_u32(dev, "keypad,num-columns", cols); if (!*rows || !*cols) { dev_err(dev, "number of keypad rows/columns not specified\n"); return -EINVAL; } return 0; } EXPORT_SYMBOL_GPL(matrix_keypad_parse_properties); static int matrix_keypad_parse_keymap(const char *propname, unsigned int rows, unsigned int cols, struct input_dev *input_dev) { struct device *dev = input_dev->dev.parent; unsigned int row_shift = get_count_order(cols); unsigned int max_keys = rows << row_shift; u32 *keys; int i; int size; int retval; if (!propname) propname = "linux,keymap"; size = device_property_read_u32_array(dev, propname, NULL, 0); if (size <= 0) { dev_err(dev, "missing or malformed property %s: %d\n", propname, size); return size < 0 ? size : -EINVAL; } if (size > max_keys) { dev_err(dev, "%s size overflow (%d vs max %u)\n", propname, size, max_keys); return -EINVAL; } keys = kmalloc_array(size, sizeof(u32), GFP_KERNEL); if (!keys) return -ENOMEM; retval = device_property_read_u32_array(dev, propname, keys, size); if (retval) { dev_err(dev, "failed to read %s property: %d\n", propname, retval); goto out; } for (i = 0; i < size; i++) { if (!matrix_keypad_map_key(input_dev, rows, cols, row_shift, keys[i])) { retval = -EINVAL; goto out; } } retval = 0; out: kfree(keys); return retval; } /** * matrix_keypad_build_keymap - convert platform keymap into matrix keymap * @keymap_data: keymap supplied by the platform code * @keymap_name: name of device tree property containing keymap (if device * tree support is enabled). * @rows: number of rows in target keymap array * @cols: number of cols in target keymap array * @keymap: expanded version of keymap that is suitable for use by * matrix keyboard driver * @input_dev: input devices for which we are setting up the keymap * * This function converts platform keymap (encoded with KEY() macro) into * an array of keycodes that is suitable for using in a standard matrix * keyboard driver that uses row and col as indices. * * If @keymap_data is not supplied and device tree support is enabled * it will attempt load the keymap from property specified by @keymap_name * argument (or "linux,keymap" if @keymap_name is %NULL). * * If @keymap is %NULL the function will automatically allocate managed * block of memory to store the keymap. This memory will be associated with * the parent device and automatically freed when device unbinds from the * driver. * * Callers are expected to set up input_dev->dev.parent before calling this * function. */ int matrix_keypad_build_keymap(const struct matrix_keymap_data *keymap_data, const char *keymap_name, unsigned int rows, unsigned int cols, unsigned short *keymap, struct input_dev *input_dev) { unsigned int row_shift = get_count_order(cols); size_t max_keys = rows << row_shift; int i; int error; if (WARN_ON(!input_dev->dev.parent)) return -EINVAL; if (!keymap) { keymap = devm_kcalloc(input_dev->dev.parent, max_keys, sizeof(*keymap), GFP_KERNEL); if (!keymap) { dev_err(input_dev->dev.parent, "Unable to allocate memory for keymap"); return -ENOMEM; } } input_dev->keycode = keymap; input_dev->keycodesize = sizeof(*keymap); input_dev->keycodemax = max_keys; __set_bit(EV_KEY, input_dev->evbit); if (keymap_data) { for (i = 0; i < keymap_data->keymap_size; i++) { unsigned int key = keymap_data->keymap[i]; if (!matrix_keypad_map_key(input_dev, rows, cols, row_shift, key)) return -EINVAL; } } else { error = matrix_keypad_parse_keymap(keymap_name, rows, cols, input_dev); if (error) return error; } __clear_bit(KEY_RESERVED, input_dev->keybit); return 0; } EXPORT_SYMBOL(matrix_keypad_build_keymap); MODULE_LICENSE("GPL");