1 /*
2 * qt2160.c - Atmel AT42QT2160 Touch Sense Controller
3 *
4 * Copyright (C) 2009 Raphael Derosso Pereira <raphaelpereira@gmail.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21 #include <linux/kernel.h>
22 #include <linux/init.h>
23 #include <linux/module.h>
24 #include <linux/slab.h>
25 #include <linux/jiffies.h>
26 #include <linux/i2c.h>
27 #include <linux/irq.h>
28 #include <linux/interrupt.h>
29 #include <linux/input.h>
30
31 #define QT2160_VALID_CHIPID 0x11
32
33 #define QT2160_CMD_CHIPID 0
34 #define QT2160_CMD_CODEVER 1
35 #define QT2160_CMD_GSTAT 2
36 #define QT2160_CMD_KEYS3 3
37 #define QT2160_CMD_KEYS4 4
38 #define QT2160_CMD_SLIDE 5
39 #define QT2160_CMD_GPIOS 6
40 #define QT2160_CMD_SUBVER 7
41 #define QT2160_CMD_CALIBRATE 10
42
43 #define QT2160_CYCLE_INTERVAL (2*HZ)
44
45 static unsigned char qt2160_key2code[] = {
46 KEY_0, KEY_1, KEY_2, KEY_3,
47 KEY_4, KEY_5, KEY_6, KEY_7,
48 KEY_8, KEY_9, KEY_A, KEY_B,
49 KEY_C, KEY_D, KEY_E, KEY_F,
50 };
51
52 struct qt2160_data {
53 struct i2c_client *client;
54 struct input_dev *input;
55 struct delayed_work dwork;
56 spinlock_t lock; /* Protects canceling/rescheduling of dwork */
57 unsigned short keycodes[ARRAY_SIZE(qt2160_key2code)];
58 u16 key_matrix;
59 };
60
qt2160_read_block(struct i2c_client * client,u8 inireg,u8 * buffer,unsigned int count)61 static int qt2160_read_block(struct i2c_client *client,
62 u8 inireg, u8 *buffer, unsigned int count)
63 {
64 int error, idx = 0;
65
66 /*
67 * Can't use SMBus block data read. Check for I2C functionality to speed
68 * things up whenever possible. Otherwise we will be forced to read
69 * sequentially.
70 */
71 if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
72
73 error = i2c_smbus_write_byte(client, inireg + idx);
74 if (error) {
75 dev_err(&client->dev,
76 "couldn't send request. Returned %d\n", error);
77 return error;
78 }
79
80 error = i2c_master_recv(client, buffer, count);
81 if (error != count) {
82 dev_err(&client->dev,
83 "couldn't read registers. Returned %d bytes\n", error);
84 return error;
85 }
86 } else {
87
88 while (count--) {
89 int data;
90
91 error = i2c_smbus_write_byte(client, inireg + idx);
92 if (error) {
93 dev_err(&client->dev,
94 "couldn't send request. Returned %d\n", error);
95 return error;
96 }
97
98 data = i2c_smbus_read_byte(client);
99 if (data < 0) {
100 dev_err(&client->dev,
101 "couldn't read register. Returned %d\n", data);
102 return data;
103 }
104
105 buffer[idx++] = data;
106 }
107 }
108
109 return 0;
110 }
111
qt2160_get_key_matrix(struct qt2160_data * qt2160)112 static int qt2160_get_key_matrix(struct qt2160_data *qt2160)
113 {
114 struct i2c_client *client = qt2160->client;
115 struct input_dev *input = qt2160->input;
116 u8 regs[6];
117 u16 old_matrix, new_matrix;
118 int ret, i, mask;
119
120 dev_dbg(&client->dev, "requesting keys...\n");
121
122 /*
123 * Read all registers from General Status Register
124 * to GPIOs register
125 */
126 ret = qt2160_read_block(client, QT2160_CMD_GSTAT, regs, 6);
127 if (ret) {
128 dev_err(&client->dev,
129 "could not perform chip read.\n");
130 return ret;
131 }
132
133 old_matrix = qt2160->key_matrix;
134 qt2160->key_matrix = new_matrix = (regs[2] << 8) | regs[1];
135
136 mask = 0x01;
137 for (i = 0; i < 16; ++i, mask <<= 1) {
138 int keyval = new_matrix & mask;
139
140 if ((old_matrix & mask) != keyval) {
141 input_report_key(input, qt2160->keycodes[i], keyval);
142 dev_dbg(&client->dev, "key %d %s\n",
143 i, keyval ? "pressed" : "released");
144 }
145 }
146
147 input_sync(input);
148
149 return 0;
150 }
151
qt2160_irq(int irq,void * _qt2160)152 static irqreturn_t qt2160_irq(int irq, void *_qt2160)
153 {
154 struct qt2160_data *qt2160 = _qt2160;
155 unsigned long flags;
156
157 spin_lock_irqsave(&qt2160->lock, flags);
158
159 __cancel_delayed_work(&qt2160->dwork);
160 schedule_delayed_work(&qt2160->dwork, 0);
161
162 spin_unlock_irqrestore(&qt2160->lock, flags);
163
164 return IRQ_HANDLED;
165 }
166
qt2160_schedule_read(struct qt2160_data * qt2160)167 static void qt2160_schedule_read(struct qt2160_data *qt2160)
168 {
169 spin_lock_irq(&qt2160->lock);
170 schedule_delayed_work(&qt2160->dwork, QT2160_CYCLE_INTERVAL);
171 spin_unlock_irq(&qt2160->lock);
172 }
173
qt2160_worker(struct work_struct * work)174 static void qt2160_worker(struct work_struct *work)
175 {
176 struct qt2160_data *qt2160 =
177 container_of(work, struct qt2160_data, dwork.work);
178
179 dev_dbg(&qt2160->client->dev, "worker\n");
180
181 qt2160_get_key_matrix(qt2160);
182
183 /* Avoid device lock up by checking every so often */
184 qt2160_schedule_read(qt2160);
185 }
186
qt2160_read(struct i2c_client * client,u8 reg)187 static int __devinit qt2160_read(struct i2c_client *client, u8 reg)
188 {
189 int ret;
190
191 ret = i2c_smbus_write_byte(client, reg);
192 if (ret) {
193 dev_err(&client->dev,
194 "couldn't send request. Returned %d\n", ret);
195 return ret;
196 }
197
198 ret = i2c_smbus_read_byte(client);
199 if (ret < 0) {
200 dev_err(&client->dev,
201 "couldn't read register. Returned %d\n", ret);
202 return ret;
203 }
204
205 return ret;
206 }
207
qt2160_write(struct i2c_client * client,u8 reg,u8 data)208 static int __devinit qt2160_write(struct i2c_client *client, u8 reg, u8 data)
209 {
210 int error;
211
212 error = i2c_smbus_write_byte(client, reg);
213 if (error) {
214 dev_err(&client->dev,
215 "couldn't send request. Returned %d\n", error);
216 return error;
217 }
218
219 error = i2c_smbus_write_byte(client, data);
220 if (error) {
221 dev_err(&client->dev,
222 "couldn't write data. Returned %d\n", error);
223 return error;
224 }
225
226 return error;
227 }
228
229
qt2160_identify(struct i2c_client * client)230 static bool __devinit qt2160_identify(struct i2c_client *client)
231 {
232 int id, ver, rev;
233
234 /* Read Chid ID to check if chip is valid */
235 id = qt2160_read(client, QT2160_CMD_CHIPID);
236 if (id != QT2160_VALID_CHIPID) {
237 dev_err(&client->dev, "ID %d not supported\n", id);
238 return false;
239 }
240
241 /* Read chip firmware version */
242 ver = qt2160_read(client, QT2160_CMD_CODEVER);
243 if (ver < 0) {
244 dev_err(&client->dev, "could not get firmware version\n");
245 return false;
246 }
247
248 /* Read chip firmware revision */
249 rev = qt2160_read(client, QT2160_CMD_SUBVER);
250 if (rev < 0) {
251 dev_err(&client->dev, "could not get firmware revision\n");
252 return false;
253 }
254
255 dev_info(&client->dev, "AT42QT2160 firmware version %d.%d.%d\n",
256 ver >> 4, ver & 0xf, rev);
257
258 return true;
259 }
260
qt2160_probe(struct i2c_client * client,const struct i2c_device_id * id)261 static int __devinit qt2160_probe(struct i2c_client *client,
262 const struct i2c_device_id *id)
263 {
264 struct qt2160_data *qt2160;
265 struct input_dev *input;
266 int i;
267 int error;
268
269 /* Check functionality */
270 error = i2c_check_functionality(client->adapter,
271 I2C_FUNC_SMBUS_BYTE);
272 if (!error) {
273 dev_err(&client->dev, "%s adapter not supported\n",
274 dev_driver_string(&client->adapter->dev));
275 return -ENODEV;
276 }
277
278 if (!qt2160_identify(client))
279 return -ENODEV;
280
281 /* Chip is valid and active. Allocate structure */
282 qt2160 = kzalloc(sizeof(struct qt2160_data), GFP_KERNEL);
283 input = input_allocate_device();
284 if (!qt2160 || !input) {
285 dev_err(&client->dev, "insufficient memory\n");
286 error = -ENOMEM;
287 goto err_free_mem;
288 }
289
290 qt2160->client = client;
291 qt2160->input = input;
292 INIT_DELAYED_WORK(&qt2160->dwork, qt2160_worker);
293 spin_lock_init(&qt2160->lock);
294
295 input->name = "AT42QT2160 Touch Sense Keyboard";
296 input->id.bustype = BUS_I2C;
297
298 input->keycode = qt2160->keycodes;
299 input->keycodesize = sizeof(qt2160->keycodes[0]);
300 input->keycodemax = ARRAY_SIZE(qt2160_key2code);
301
302 __set_bit(EV_KEY, input->evbit);
303 __clear_bit(EV_REP, input->evbit);
304 for (i = 0; i < ARRAY_SIZE(qt2160_key2code); i++) {
305 qt2160->keycodes[i] = qt2160_key2code[i];
306 __set_bit(qt2160_key2code[i], input->keybit);
307 }
308 __clear_bit(KEY_RESERVED, input->keybit);
309
310 /* Calibrate device */
311 error = qt2160_write(client, QT2160_CMD_CALIBRATE, 1);
312 if (error) {
313 dev_err(&client->dev, "failed to calibrate device\n");
314 goto err_free_mem;
315 }
316
317 if (client->irq) {
318 error = request_irq(client->irq, qt2160_irq,
319 IRQF_TRIGGER_FALLING, "qt2160", qt2160);
320 if (error) {
321 dev_err(&client->dev,
322 "failed to allocate irq %d\n", client->irq);
323 goto err_free_mem;
324 }
325 }
326
327 error = input_register_device(qt2160->input);
328 if (error) {
329 dev_err(&client->dev,
330 "Failed to register input device\n");
331 goto err_free_irq;
332 }
333
334 i2c_set_clientdata(client, qt2160);
335 qt2160_schedule_read(qt2160);
336
337 return 0;
338
339 err_free_irq:
340 if (client->irq)
341 free_irq(client->irq, qt2160);
342 err_free_mem:
343 input_free_device(input);
344 kfree(qt2160);
345 return error;
346 }
347
qt2160_remove(struct i2c_client * client)348 static int __devexit qt2160_remove(struct i2c_client *client)
349 {
350 struct qt2160_data *qt2160 = i2c_get_clientdata(client);
351
352 /* Release IRQ so no queue will be scheduled */
353 if (client->irq)
354 free_irq(client->irq, qt2160);
355
356 cancel_delayed_work_sync(&qt2160->dwork);
357
358 input_unregister_device(qt2160->input);
359 kfree(qt2160);
360
361 return 0;
362 }
363
364 static const struct i2c_device_id qt2160_idtable[] = {
365 { "qt2160", 0, },
366 { }
367 };
368
369 MODULE_DEVICE_TABLE(i2c, qt2160_idtable);
370
371 static struct i2c_driver qt2160_driver = {
372 .driver = {
373 .name = "qt2160",
374 .owner = THIS_MODULE,
375 },
376
377 .id_table = qt2160_idtable,
378 .probe = qt2160_probe,
379 .remove = __devexit_p(qt2160_remove),
380 };
381
qt2160_init(void)382 static int __init qt2160_init(void)
383 {
384 return i2c_add_driver(&qt2160_driver);
385 }
386 module_init(qt2160_init);
387
qt2160_cleanup(void)388 static void __exit qt2160_cleanup(void)
389 {
390 i2c_del_driver(&qt2160_driver);
391 }
392 module_exit(qt2160_cleanup);
393
394 MODULE_AUTHOR("Raphael Derosso Pereira <raphaelpereira@gmail.com>");
395 MODULE_DESCRIPTION("Driver for AT42QT2160 Touch Sensor");
396 MODULE_LICENSE("GPL");
397