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 | #include <linux/device.h> |
20 | #include <linux/export.h> |
21 | #include <linux/gfp.h> |
22 | #include <linux/input.h> |
23 | #include <linux/input/matrix_keypad.h> |
24 | #include <linux/kernel.h> |
25 | #include <linux/module.h> |
26 | #include <linux/property.h> |
27 | #include <linux/slab.h> |
28 | #include <linux/types.h> |
29 | |
30 | static 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 | /** |
53 | * matrix_keypad_parse_properties() - Read properties of matrix keypad |
54 | * |
55 | * @dev: Device containing properties |
56 | * @rows: Returns number of matrix rows |
57 | * @cols: Returns number of matrix columns |
58 | * @return 0 if OK, <0 on error |
59 | */ |
60 | int matrix_keypad_parse_properties(struct device *dev, |
61 | unsigned int *rows, unsigned int *cols) |
62 | { |
63 | *rows = *cols = 0; |
64 | |
65 | device_property_read_u32(dev, "keypad,num-rows" , rows); |
66 | device_property_read_u32(dev, "keypad,num-columns" , cols); |
67 | |
68 | if (!*rows || !*cols) { |
69 | dev_err(dev, "number of keypad rows/columns not specified\n" ); |
70 | return -EINVAL; |
71 | } |
72 | |
73 | return 0; |
74 | } |
75 | EXPORT_SYMBOL_GPL(matrix_keypad_parse_properties); |
76 | |
77 | static int matrix_keypad_parse_keymap(const char *propname, |
78 | unsigned int rows, unsigned int cols, |
79 | struct input_dev *input_dev) |
80 | { |
81 | struct device *dev = input_dev->dev.parent; |
82 | unsigned int row_shift = get_count_order(cols); |
83 | unsigned int max_keys = rows << row_shift; |
84 | u32 *keys; |
85 | int i; |
86 | int size; |
87 | int retval; |
88 | |
89 | if (!propname) |
90 | propname = "linux,keymap" ; |
91 | |
92 | size = device_property_read_u32_array(dev, propname, NULL, 0); |
93 | if (size <= 0) { |
94 | dev_err(dev, "missing or malformed property %s: %d\n" , |
95 | propname, size); |
96 | return size < 0 ? size : -EINVAL; |
97 | } |
98 | |
99 | if (size > max_keys) { |
100 | dev_err(dev, "%s size overflow (%d vs max %u)\n" , |
101 | propname, size, max_keys); |
102 | return -EINVAL; |
103 | } |
104 | |
105 | keys = kmalloc_array(size, sizeof(u32), GFP_KERNEL); |
106 | if (!keys) |
107 | return -ENOMEM; |
108 | |
109 | retval = device_property_read_u32_array(dev, propname, keys, size); |
110 | if (retval) { |
111 | dev_err(dev, "failed to read %s property: %d\n" , |
112 | propname, retval); |
113 | goto out; |
114 | } |
115 | |
116 | for (i = 0; i < size; i++) { |
117 | if (!matrix_keypad_map_key(input_dev, rows, cols, |
118 | row_shift, keys[i])) { |
119 | retval = -EINVAL; |
120 | goto out; |
121 | } |
122 | } |
123 | |
124 | retval = 0; |
125 | |
126 | out: |
127 | kfree(keys); |
128 | return retval; |
129 | } |
130 | |
131 | /** |
132 | * matrix_keypad_build_keymap - convert platform keymap into matrix keymap |
133 | * @keymap_data: keymap supplied by the platform code |
134 | * @keymap_name: name of device tree property containing keymap (if device |
135 | * tree support is enabled). |
136 | * @rows: number of rows in target keymap array |
137 | * @cols: number of cols in target keymap array |
138 | * @keymap: expanded version of keymap that is suitable for use by |
139 | * matrix keyboard driver |
140 | * @input_dev: input devices for which we are setting up the keymap |
141 | * |
142 | * This function converts platform keymap (encoded with KEY() macro) into |
143 | * an array of keycodes that is suitable for using in a standard matrix |
144 | * keyboard driver that uses row and col as indices. |
145 | * |
146 | * If @keymap_data is not supplied and device tree support is enabled |
147 | * it will attempt load the keymap from property specified by @keymap_name |
148 | * argument (or "linux,keymap" if @keymap_name is %NULL). |
149 | * |
150 | * If @keymap is %NULL the function will automatically allocate managed |
151 | * block of memory to store the keymap. This memory will be associated with |
152 | * the parent device and automatically freed when device unbinds from the |
153 | * driver. |
154 | * |
155 | * Callers are expected to set up input_dev->dev.parent before calling this |
156 | * function. |
157 | */ |
158 | int matrix_keypad_build_keymap(const struct matrix_keymap_data *keymap_data, |
159 | const char *keymap_name, |
160 | unsigned int rows, unsigned int cols, |
161 | unsigned short *keymap, |
162 | struct input_dev *input_dev) |
163 | { |
164 | unsigned int row_shift = get_count_order(cols); |
165 | size_t max_keys = rows << row_shift; |
166 | int i; |
167 | int error; |
168 | |
169 | if (WARN_ON(!input_dev->dev.parent)) |
170 | return -EINVAL; |
171 | |
172 | if (!keymap) { |
173 | keymap = devm_kcalloc(input_dev->dev.parent, |
174 | max_keys, sizeof(*keymap), |
175 | GFP_KERNEL); |
176 | if (!keymap) { |
177 | dev_err(input_dev->dev.parent, |
178 | "Unable to allocate memory for keymap" ); |
179 | return -ENOMEM; |
180 | } |
181 | } |
182 | |
183 | input_dev->keycode = keymap; |
184 | input_dev->keycodesize = sizeof(*keymap); |
185 | input_dev->keycodemax = max_keys; |
186 | |
187 | __set_bit(EV_KEY, input_dev->evbit); |
188 | |
189 | if (keymap_data) { |
190 | for (i = 0; i < keymap_data->keymap_size; i++) { |
191 | unsigned int key = keymap_data->keymap[i]; |
192 | |
193 | if (!matrix_keypad_map_key(input_dev, rows, cols, |
194 | row_shift, key)) |
195 | return -EINVAL; |
196 | } |
197 | } else { |
198 | error = matrix_keypad_parse_keymap(keymap_name, rows, cols, |
199 | input_dev); |
200 | if (error) |
201 | return error; |
202 | } |
203 | |
204 | __clear_bit(KEY_RESERVED, input_dev->keybit); |
205 | |
206 | return 0; |
207 | } |
208 | EXPORT_SYMBOL(matrix_keypad_build_keymap); |
209 | |
210 | MODULE_LICENSE("GPL" ); |
211 | |