/* * 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_kzalloc(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");