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/kernel.h>
 22#include <linux/types.h>
 23#include <linux/input.h>
 24#include <linux/of.h>
 25#include <linux/export.h>
 26#include <linux/input/matrix_keypad.h>
 27
 28static bool matrix_keypad_map_key(struct input_dev *input_dev,
 29				  unsigned int rows, unsigned int cols,
 30				  unsigned int row_shift, unsigned int key)
 31{
 32	unsigned short *keymap = input_dev->keycode;
 33	unsigned int row = KEY_ROW(key);
 34	unsigned int col = KEY_COL(key);
 35	unsigned short code = KEY_VAL(key);
 36
 37	if (row >= rows || col >= cols) {
 38		dev_err(input_dev->dev.parent,
 39			"%s: invalid keymap entry 0x%x (row: %d, col: %d, rows: %d, cols: %d)\n",
 40			__func__, key, row, col, rows, cols);
 41		return false;
 42	}
 43
 44	keymap[MATRIX_SCAN_CODE(row, col, row_shift)] = code;
 45	__set_bit(code, input_dev->keybit);
 46
 47	return true;
 48}
 49
 50#ifdef CONFIG_OF
 51static int matrix_keypad_parse_of_keymap(const char *propname,
 52					 unsigned int rows, unsigned int cols,
 53					 struct input_dev *input_dev)
 54{
 55	struct device *dev = input_dev->dev.parent;
 56	struct device_node *np = dev->of_node;
 57	unsigned int row_shift = get_count_order(cols);
 58	unsigned int max_keys = rows << row_shift;
 59	unsigned int proplen, i, size;
 60	const __be32 *prop;
 61
 62	if (!np)
 63		return -ENOENT;
 64
 65	if (!propname)
 66		propname = "linux,keymap";
 67
 68	prop = of_get_property(np, propname, &proplen);
 69	if (!prop) {
 70		dev_err(dev, "OF: %s property not defined in %s\n",
 71			propname, np->full_name);
 72		return -ENOENT;
 73	}
 74
 75	if (proplen % sizeof(u32)) {
 76		dev_err(dev, "OF: Malformed keycode property %s in %s\n",
 77			propname, np->full_name);
 78		return -EINVAL;
 79	}
 80
 81	size = proplen / sizeof(u32);
 82	if (size > max_keys) {
 83		dev_err(dev, "OF: %s size overflow\n", propname);
 84		return -EINVAL;
 85	}
 86
 87	for (i = 0; i < size; i++) {
 88		unsigned int key = be32_to_cpup(prop + i);
 89
 90		if (!matrix_keypad_map_key(input_dev, rows, cols,
 91					   row_shift, key))
 92			return -EINVAL;
 93	}
 94
 95	return 0;
 96}
 97#else
 98static int matrix_keypad_parse_of_keymap(const char *propname,
 99					 unsigned int rows, unsigned int cols,
100					 struct input_dev *input_dev)
101{
102	return -ENOSYS;
103}
104#endif
105
106/**
107 * matrix_keypad_build_keymap - convert platform keymap into matrix keymap
108 * @keymap_data: keymap supplied by the platform code
109 * @keymap_name: name of device tree property containing keymap (if device
110 *	tree support is enabled).
111 * @rows: number of rows in target keymap array
112 * @cols: number of cols in target keymap array
113 * @keymap: expanded version of keymap that is suitable for use by
114 * matrix keyboard driver
115 * @input_dev: input devices for which we are setting up the keymap
116 *
117 * This function converts platform keymap (encoded with KEY() macro) into
118 * an array of keycodes that is suitable for using in a standard matrix
119 * keyboard driver that uses row and col as indices.
120 *
121 * If @keymap_data is not supplied and device tree support is enabled
122 * it will attempt load the keymap from property specified by @keymap_name
123 * argument (or "linux,keymap" if @keymap_name is %NULL).
124 *
125 * Callers are expected to set up input_dev->dev.parent before calling this
126 * function.
127 */
128int matrix_keypad_build_keymap(const struct matrix_keymap_data *keymap_data,
129			       const char *keymap_name,
130			       unsigned int rows, unsigned int cols,
131			       unsigned short *keymap,
132			       struct input_dev *input_dev)
133{
134	unsigned int row_shift = get_count_order(cols);
135	int i;
136	int error;
137
138	input_dev->keycode = keymap;
139	input_dev->keycodesize = sizeof(*keymap);
140	input_dev->keycodemax = rows << row_shift;
141
142	__set_bit(EV_KEY, input_dev->evbit);
143
144	if (keymap_data) {
145		for (i = 0; i < keymap_data->keymap_size; i++) {
146			unsigned int key = keymap_data->keymap[i];
147
148			if (!matrix_keypad_map_key(input_dev, rows, cols,
149						   row_shift, key))
150				return -EINVAL;
151		}
152	} else {
153		error = matrix_keypad_parse_of_keymap(keymap_name, rows, cols,
154						      input_dev);
155		if (error)
156			return error;
157	}
158
159	__clear_bit(KEY_RESERVED, input_dev->keybit);
160
161	return 0;
162}
163EXPORT_SYMBOL(matrix_keypad_build_keymap);