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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
22static 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 */
52int 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}
67EXPORT_SYMBOL_GPL(matrix_keypad_parse_properties);
68
69static 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 int i;
77 int size;
78 int error;
79
80 if (!propname)
81 propname = "linux,keymap";
82
83 size = device_property_count_u32(dev, propname);
84 if (size <= 0) {
85 dev_err(dev, "missing or malformed property %s: %d\n",
86 propname, size);
87 return size < 0 ? size : -EINVAL;
88 }
89
90 if (size > max_keys) {
91 dev_err(dev, "%s size overflow (%d vs max %u)\n",
92 propname, size, max_keys);
93 return -EINVAL;
94 }
95
96 u32 *keys __free(kfree) = kmalloc_array(size, sizeof(*keys), GFP_KERNEL);
97 if (!keys)
98 return -ENOMEM;
99
100 error = device_property_read_u32_array(dev, propname, keys, size);
101 if (error) {
102 dev_err(dev, "failed to read %s property: %d\n",
103 propname, error);
104 return error;
105 }
106
107 for (i = 0; i < size; i++) {
108 if (!matrix_keypad_map_key(input_dev, rows, cols,
109 row_shift, keys[i]))
110 return -EINVAL;
111 }
112
113 return 0;
114}
115
116/**
117 * matrix_keypad_build_keymap - convert platform keymap into matrix keymap
118 * @keymap_data: keymap supplied by the platform code
119 * @keymap_name: name of device tree property containing keymap (if device
120 * tree support is enabled).
121 * @rows: number of rows in target keymap array
122 * @cols: number of cols in target keymap array
123 * @keymap: expanded version of keymap that is suitable for use by
124 * matrix keyboard driver
125 * @input_dev: input devices for which we are setting up the keymap
126 *
127 * This function converts platform keymap (encoded with KEY() macro) into
128 * an array of keycodes that is suitable for using in a standard matrix
129 * keyboard driver that uses row and col as indices.
130 *
131 * If @keymap_data is not supplied and device tree support is enabled
132 * it will attempt load the keymap from property specified by @keymap_name
133 * argument (or "linux,keymap" if @keymap_name is %NULL).
134 *
135 * If @keymap is %NULL the function will automatically allocate managed
136 * block of memory to store the keymap. This memory will be associated with
137 * the parent device and automatically freed when device unbinds from the
138 * driver.
139 *
140 * Callers are expected to set up input_dev->dev.parent before calling this
141 * function.
142 */
143int matrix_keypad_build_keymap(const struct matrix_keymap_data *keymap_data,
144 const char *keymap_name,
145 unsigned int rows, unsigned int cols,
146 unsigned short *keymap,
147 struct input_dev *input_dev)
148{
149 unsigned int row_shift = get_count_order(cols);
150 size_t max_keys = rows << row_shift;
151 int i;
152 int error;
153
154 if (WARN_ON(!input_dev->dev.parent))
155 return -EINVAL;
156
157 if (!keymap) {
158 keymap = devm_kcalloc(input_dev->dev.parent,
159 max_keys, sizeof(*keymap),
160 GFP_KERNEL);
161 if (!keymap) {
162 dev_err(input_dev->dev.parent,
163 "Unable to allocate memory for keymap");
164 return -ENOMEM;
165 }
166 }
167
168 input_dev->keycode = keymap;
169 input_dev->keycodesize = sizeof(*keymap);
170 input_dev->keycodemax = max_keys;
171
172 __set_bit(EV_KEY, input_dev->evbit);
173
174 if (keymap_data) {
175 for (i = 0; i < keymap_data->keymap_size; i++) {
176 unsigned int key = keymap_data->keymap[i];
177
178 if (!matrix_keypad_map_key(input_dev, rows, cols,
179 row_shift, key))
180 return -EINVAL;
181 }
182 } else {
183 error = matrix_keypad_parse_keymap(keymap_name, rows, cols,
184 input_dev);
185 if (error)
186 return error;
187 }
188
189 __clear_bit(KEY_RESERVED, input_dev->keybit);
190
191 return 0;
192}
193EXPORT_SYMBOL(matrix_keypad_build_keymap);
194
195MODULE_DESCRIPTION("Helpers for matrix keyboard bindings");
196MODULE_LICENSE("GPL");
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);