blob: fba8404c7297536d80fcbc2a3efac6129f996ace [file] [log] [blame]
Bo Shenbd7e4e82011-03-13 23:34:59 -07001/*
2 * Atmel AT42QT1070 QTouch Sensor Controller
3 *
4 * Copyright (C) 2011 Atmel
5 *
6 * Authors: Bo Shen <voice.shen@atmel.com>
7 *
8 * Base on AT42QT2160 driver by:
9 * Raphael Derosso Pereira <raphaelpereira@gmail.com>
10 * Copyright (C) 2009
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 */
26#include <linux/kernel.h>
27#include <linux/module.h>
28#include <linux/init.h>
29#include <linux/i2c.h>
30#include <linux/input.h>
31#include <linux/slab.h>
32#include <linux/irq.h>
33#include <linux/interrupt.h>
34#include <linux/jiffies.h>
35#include <linux/delay.h>
36
37/* Address for each register */
38#define CHIP_ID 0x00
39#define QT1070_CHIP_ID 0x2E
40
41#define FW_VERSION 0x01
42#define QT1070_FW_VERSION 0x15
43
44#define DET_STATUS 0x02
45
46#define KEY_STATUS 0x03
47
48/* Calibrate */
49#define CALIBRATE_CMD 0x38
50#define QT1070_CAL_TIME 200
51
52/* Reset */
53#define RESET 0x39
54#define QT1070_RESET_TIME 255
55
56/* AT42QT1070 support up to 7 keys */
57static const unsigned short qt1070_key2code[] = {
58 KEY_0, KEY_1, KEY_2, KEY_3,
59 KEY_4, KEY_5, KEY_6,
60};
61
62struct qt1070_data {
63 struct i2c_client *client;
64 struct input_dev *input;
65 unsigned int irq;
66 unsigned short keycodes[ARRAY_SIZE(qt1070_key2code)];
67 u8 last_keys;
68};
69
70static int qt1070_read(struct i2c_client *client, u8 reg)
71{
72 int ret;
73
74 ret = i2c_smbus_read_byte_data(client, reg);
75 if (ret < 0)
76 dev_err(&client->dev,
77 "can not read register, returned %d\n", ret);
78
79 return ret;
80}
81
82static int qt1070_write(struct i2c_client *client, u8 reg, u8 data)
83{
84 int ret;
85
86 ret = i2c_smbus_write_byte_data(client, reg, data);
87 if (ret < 0)
88 dev_err(&client->dev,
89 "can not write register, returned %d\n", ret);
90
91 return ret;
92}
93
94static bool __devinit qt1070_identify(struct i2c_client *client)
95{
96 int id, ver;
97
98 /* Read Chip ID */
99 id = qt1070_read(client, CHIP_ID);
100 if (id != QT1070_CHIP_ID) {
101 dev_err(&client->dev, "ID %d not supported\n", id);
102 return false;
103 }
104
105 /* Read firmware version */
106 ver = qt1070_read(client, FW_VERSION);
107 if (ver < 0) {
108 dev_err(&client->dev, "could not read the firmware version\n");
109 return false;
110 }
111
112 dev_info(&client->dev, "AT42QT1070 firmware version %x\n", ver);
113
114 return true;
115}
116
117static irqreturn_t qt1070_interrupt(int irq, void *dev_id)
118{
119 struct qt1070_data *data = dev_id;
120 struct i2c_client *client = data->client;
121 struct input_dev *input = data->input;
122 int i;
123 u8 new_keys, keyval, mask = 0x01;
124
125 /* Read the detected status register, thus clearing interrupt */
126 qt1070_read(client, DET_STATUS);
127
128 /* Read which key changed */
129 new_keys = qt1070_read(client, KEY_STATUS);
130
131 for (i = 0; i < ARRAY_SIZE(qt1070_key2code); i++) {
132 keyval = new_keys & mask;
133 if ((data->last_keys & mask) != keyval)
134 input_report_key(input, data->keycodes[i], keyval);
135 mask <<= 1;
136 }
137 input_sync(input);
138
139 data->last_keys = new_keys;
140 return IRQ_HANDLED;
141}
142
143static int __devinit qt1070_probe(struct i2c_client *client,
144 const struct i2c_device_id *id)
145{
146 struct qt1070_data *data;
147 struct input_dev *input;
148 int i;
149 int err;
150
151 err = i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE);
152 if (!err) {
153 dev_err(&client->dev, "%s adapter not supported\n",
154 dev_driver_string(&client->adapter->dev));
155 return -ENODEV;
156 }
157
158 if (!client->irq) {
159 dev_err(&client->dev, "please assign the irq to this device\n");
160 return -EINVAL;
161 }
162
163 /* Identify the qt1070 chip */
164 if (!qt1070_identify(client))
165 return -ENODEV;
166
167 data = kzalloc(sizeof(struct qt1070_data), GFP_KERNEL);
168 input = input_allocate_device();
169 if (!data || !input) {
170 dev_err(&client->dev, "insufficient memory\n");
171 err = -ENOMEM;
172 goto err_free_mem;
173 }
174
175 data->client = client;
176 data->input = input;
177 data->irq = client->irq;
178
179 input->name = "AT42QT1070 QTouch Sensor";
180 input->dev.parent = &client->dev;
181 input->id.bustype = BUS_I2C;
182
183 /* Add the keycode */
184 input->keycode = data->keycodes;
185 input->keycodesize = sizeof(data->keycodes[0]);
186 input->keycodemax = ARRAY_SIZE(qt1070_key2code);
187
188 __set_bit(EV_KEY, input->evbit);
189
190 for (i = 0; i < ARRAY_SIZE(qt1070_key2code); i++) {
191 data->keycodes[i] = qt1070_key2code[i];
192 __set_bit(qt1070_key2code[i], input->keybit);
193 }
194
195 /* Calibrate device */
196 qt1070_write(client, CALIBRATE_CMD, 1);
197 msleep(QT1070_CAL_TIME);
198
199 /* Soft reset */
200 qt1070_write(client, RESET, 1);
201 msleep(QT1070_RESET_TIME);
202
203 err = request_threaded_irq(client->irq, NULL, qt1070_interrupt,
204 IRQF_TRIGGER_NONE, client->dev.driver->name, data);
205 if (err) {
206 dev_err(&client->dev, "fail to request irq\n");
207 goto err_free_mem;
208 }
209
210 /* Register the input device */
211 err = input_register_device(data->input);
212 if (err) {
213 dev_err(&client->dev, "Failed to register input device\n");
214 goto err_free_irq;
215 }
216
217 i2c_set_clientdata(client, data);
218
219 /* Read to clear the chang line */
220 qt1070_read(client, DET_STATUS);
221
222 return 0;
223
224err_free_irq:
225 free_irq(client->irq, data);
226err_free_mem:
227 input_free_device(input);
228 kfree(data);
229 return err;
230}
231
232static int __devexit qt1070_remove(struct i2c_client *client)
233{
234 struct qt1070_data *data = i2c_get_clientdata(client);
235
236 /* Release IRQ */
237 free_irq(client->irq, data);
238
239 input_unregister_device(data->input);
240 kfree(data);
241
242 i2c_set_clientdata(client, NULL);
243
244 return 0;
245}
246
247static const struct i2c_device_id qt1070_id[] = {
248 { "qt1070", 0 },
249 { },
250};
251
252static struct i2c_driver qt1070_driver = {
253 .driver = {
254 .name = "qt1070",
255 .owner = THIS_MODULE,
256 },
257 .id_table = qt1070_id,
258 .probe = qt1070_probe,
259 .remove = __devexit_p(qt1070_remove),
260};
261
262static int __init qt1070_init(void)
263{
264 return i2c_add_driver(&qt1070_driver);
265}
266module_init(qt1070_init);
267
268static void __exit qt1070_exit(void)
269{
270 i2c_del_driver(&qt1070_driver);
271}
272module_exit(qt1070_exit);
273
274MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>");
275MODULE_DESCRIPTION("Driver for AT42QT1070 QTouch sensor");
276MODULE_LICENSE("GPL");