xref: /openbmc/linux/drivers/input/keyboard/qt1070.c (revision 0d456bad) 
1 /*
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 */
57 static const unsigned short qt1070_key2code[] = {
58 	KEY_0, KEY_1, KEY_2, KEY_3,
59 	KEY_4, KEY_5, KEY_6,
60 };
61 
62 struct 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 
70 static 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 
82 static 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 
94 static bool 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 
117 static 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 
143 static int 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 | IRQF_ONESHOT,
205 				   client->dev.driver->name, data);
206 	if (err) {
207 		dev_err(&client->dev, "fail to request irq\n");
208 		goto err_free_mem;
209 	}
210 
211 	/* Register the input device */
212 	err = input_register_device(data->input);
213 	if (err) {
214 		dev_err(&client->dev, "Failed to register input device\n");
215 		goto err_free_irq;
216 	}
217 
218 	i2c_set_clientdata(client, data);
219 
220 	/* Read to clear the chang line */
221 	qt1070_read(client, DET_STATUS);
222 
223 	return 0;
224 
225 err_free_irq:
226 	free_irq(client->irq, data);
227 err_free_mem:
228 	input_free_device(input);
229 	kfree(data);
230 	return err;
231 }
232 
233 static int qt1070_remove(struct i2c_client *client)
234 {
235 	struct qt1070_data *data = i2c_get_clientdata(client);
236 
237 	/* Release IRQ */
238 	free_irq(client->irq, data);
239 
240 	input_unregister_device(data->input);
241 	kfree(data);
242 
243 	return 0;
244 }
245 
246 static const struct i2c_device_id qt1070_id[] = {
247 	{ "qt1070", 0 },
248 	{ },
249 };
250 MODULE_DEVICE_TABLE(i2c, qt1070_id);
251 
252 static 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		= qt1070_remove,
260 };
261 
262 module_i2c_driver(qt1070_driver);
263 
264 MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>");
265 MODULE_DESCRIPTION("Driver for AT42QT1070 QTouch sensor");
266 MODULE_LICENSE("GPL");
267