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
 30static 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
 53int 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}
 71EXPORT_SYMBOL_GPL(matrix_keypad_parse_of_params);
 72
 73static 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
120static 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 */
155int 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}
205EXPORT_SYMBOL(matrix_keypad_build_keymap);
206
207MODULE_LICENSE("GPL");