aboutsummaryrefslogtreecommitdiff
path: root/drivers/input/keyboard/qt2160.c
blob: 819b22897c1371050a4064ba8bf81d6d7bfd1e3d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
/*
 *  qt2160.c - Atmel AT42QT2160 Touch Sense Controller
 *
 *  Copyright (C) 2009 Raphael Derosso Pereira <raphaelpereira@gmail.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/kernel.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/input.h>

#define QT2160_VALID_CHIPID  0x11

#define QT2160_CMD_CHIPID     0
#define QT2160_CMD_CODEVER    1
#define QT2160_CMD_GSTAT      2
#define QT2160_CMD_KEYS3      3
#define QT2160_CMD_KEYS4      4
#define QT2160_CMD_SLIDE      5
#define QT2160_CMD_GPIOS      6
#define QT2160_CMD_SUBVER     7
#define QT2160_CMD_CALIBRATE  10
#define QT2160_CMD_DRIVE_X    70
#define QT2160_CMD_PWMEN_X    74
#define QT2160_CMD_PWM_DUTY   76

#define QT2160_NUM_LEDS_X	8

#define QT2160_CYCLE_INTERVAL	(2*HZ)

static unsigned char qt2160_key2code[] = {
	KEY_0, KEY_1, KEY_2, KEY_3,
	KEY_4, KEY_5, KEY_6, KEY_7,
	KEY_8, KEY_9, KEY_A, KEY_B,
	KEY_C, KEY_D, KEY_E, KEY_F,
};

#ifdef CONFIG_LEDS_CLASS
struct qt2160_led {
	struct qt2160_data *qt2160;
	struct led_classdev cdev;
	struct work_struct work;
	char name[32];
	int id;
	enum led_brightness new_brightness;
};
#endif

struct qt2160_data {
	struct i2c_client *client;
	struct input_dev *input;
	struct delayed_work dwork;
	spinlock_t lock;        /* Protects canceling/rescheduling of dwork */
	unsigned short keycodes[ARRAY_SIZE(qt2160_key2code)];
	u16 key_matrix;
#ifdef CONFIG_LEDS_CLASS
	struct qt2160_led leds[QT2160_NUM_LEDS_X];
	struct mutex led_lock;
#endif
};

static int qt2160_read(struct i2c_client *client, u8 reg);
static int qt2160_write(struct i2c_client *client, u8 reg, u8 data);

#ifdef CONFIG_LEDS_CLASS

static void qt2160_led_work(struct work_struct *work)
{
	struct qt2160_led *led = container_of(work, struct qt2160_led, work);
	struct qt2160_data *qt2160 = led->qt2160;
	struct i2c_client *client = qt2160->client;
	int value = led->new_brightness;
	u32 drive, pwmen;

	mutex_lock(&qt2160->led_lock);

	drive = qt2160_read(client, QT2160_CMD_DRIVE_X);
	pwmen = qt2160_read(client, QT2160_CMD_PWMEN_X);
	if (value != LED_OFF) {
		drive |= (1 << led->id);
		pwmen |= (1 << led->id);

	} else {
		drive &= ~(1 << led->id);
		pwmen &= ~(1 << led->id);
	}
	qt2160_write(client, QT2160_CMD_DRIVE_X, drive);
	qt2160_write(client, QT2160_CMD_PWMEN_X, pwmen);

	/*
	 * Changing this register will change the brightness
	 * of every LED in the qt2160. It's a HW limitation.
	 */
	if (value != LED_OFF)
		qt2160_write(client, QT2160_CMD_PWM_DUTY, value);

	mutex_unlock(&qt2160->led_lock);
}

static void qt2160_led_set(struct led_classdev *cdev,
			   enum led_brightness value)
{
	struct qt2160_led *led = container_of(cdev, struct qt2160_led, cdev);

	led->new_brightness = value;
	schedule_work(&led->work);
}

#endif /* CONFIG_LEDS_CLASS */

static int qt2160_read_block(struct i2c_client *client,
			     u8 inireg, u8 *buffer, unsigned int count)
{
	int error, idx = 0;

	/*
	 * Can't use SMBus block data read. Check for I2C functionality to speed
	 * things up whenever possible. Otherwise we will be forced to read
	 * sequentially.
	 */
	if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C))	{

		error = i2c_smbus_write_byte(client, inireg + idx);
		if (error) {
			dev_err(&client->dev,
				"couldn't send request. Returned %d\n", error);
			return error;
		}

		error = i2c_master_recv(client, buffer, count);
		if (error != count) {
			dev_err(&client->dev,
				"couldn't read registers. Returned %d bytes\n", error);
			return error;
		}
	} else {

		while (count--) {
			int data;

			error = i2c_smbus_write_byte(client, inireg + idx);
			if (error) {
				dev_err(&client->dev,
					"couldn't send request. Returned %d\n", error);
				return error;
			}

			data = i2c_smbus_read_byte(client);
			if (data < 0) {
				dev_err(&client->dev,
					"couldn't read register. Returned %d\n", data);
				return data;
			}

			buffer[idx++] = data;
		}
	}

	return 0;
}

static int qt2160_get_key_matrix(struct qt2160_data *qt2160)
{
	struct i2c_client *client = qt2160->client;
	struct input_dev *input = qt2160->input;
	u8 regs[6];
	u16 old_matrix, new_matrix;
	int ret, i, mask;

	dev_dbg(&client->dev, "requesting keys...\n");

	/*
	 * Read all registers from General Status Register
	 * to GPIOs register
	 */
	ret = qt2160_read_block(client, QT2160_CMD_GSTAT, regs, 6);
	if (ret) {
		dev_err(&client->dev,
			"could not perform chip read.\n");
		return ret;
	}

	old_matrix = qt2160->key_matrix;
	qt2160->key_matrix = new_matrix = (regs[2] << 8) | regs[1];

	mask = 0x01;
	for (i = 0; i < 16; ++i, mask <<= 1) {
		int keyval = new_matrix & mask;

		if ((old_matrix & mask) != keyval) {
			input_report_key(input, qt2160->keycodes[i], keyval);
			dev_dbg(&client->dev, "key %d %s\n",
				i, keyval ? "pressed" : "released");
		}
	}

	input_sync(input);

	return 0;
}

static irqreturn_t qt2160_irq(int irq, void *_qt2160)
{
	struct qt2160_data *qt2160 = _qt2160;
	unsigned long flags;

	spin_lock_irqsave(&qt2160->lock, flags);

	mod_delayed_work(system_wq, &qt2160->dwork, 0);

	spin_unlock_irqrestore(&qt2160->lock, flags);

	return IRQ_HANDLED;
}

static void qt2160_schedule_read(struct qt2160_data *qt2160)
{
	spin_lock_irq(&qt2160->lock);
	schedule_delayed_work(&qt2160->dwork, QT2160_CYCLE_INTERVAL);
	spin_unlock_irq(&qt2160->lock);
}

static void qt2160_worker(struct work_struct *work)
{
	struct qt2160_data *qt2160 =
		container_of(work, struct qt2160_data, dwork.work);

	dev_dbg(&qt2160->client->dev, "worker\n");

	qt2160_get_key_matrix(qt2160);

	/* Avoid device lock up by checking every so often */
	qt2160_schedule_read(qt2160);
}

static int qt2160_read(struct i2c_client *client, u8 reg)
{
	int ret;

	ret = i2c_smbus_write_byte(client, reg);
	if (ret) {
		dev_err(&client->dev,
			"couldn't send request. Returned %d\n", ret);
		return ret;
	}

	ret = i2c_smbus_read_byte(client);
	if (ret < 0) {
		dev_err(&client->dev,
			"couldn't read register. Returned %d\n", ret);
		return ret;
	}

	return ret;
}

static int qt2160_write(struct i2c_client *client, u8 reg, u8 data)
{
	int ret;

	ret = i2c_smbus_write_byte_data(client, reg, data);
	if (ret < 0)
		dev_err(&client->dev,
			"couldn't write data. Returned %d\n", ret);

	return ret;
}

#ifdef CONFIG_LEDS_CLASS

static int qt2160_register_leds(struct qt2160_data *qt2160)
{
	struct i2c_client *client = qt2160->client;
	int ret;
	int i;

	mutex_init(&qt2160->led_lock);

	for (i = 0; i < QT2160_NUM_LEDS_X; i++) {
		struct qt2160_led *led = &qt2160->leds[i];

		snprintf(led->name, sizeof(led->name), "qt2160:x%d", i);
		led->cdev.name = led->name;
		led->cdev.brightness_set = qt2160_led_set;
		led->cdev.brightness = LED_OFF;
		led->id = i;
		led->qt2160 = qt2160;

		INIT_WORK(&led->work, qt2160_led_work);

		ret = led_classdev_register(&client->dev, &led->cdev);
		if (ret < 0)
			return ret;
	}

	/* Tur off LEDs */
	qt2160_write(client, QT2160_CMD_DRIVE_X, 0);
	qt2160_write(client, QT2160_CMD_PWMEN_X, 0);
	qt2160_write(client, QT2160_CMD_PWM_DUTY, 0);

	return 0;
}

static void qt2160_unregister_leds(struct qt2160_data *qt2160)
{
	int i;

	for (i = 0; i < QT2160_NUM_LEDS_X; i++) {
		led_classdev_unregister(&qt2160->leds[i].cdev);
		cancel_work_sync(&qt2160->leds[i].work);
	}
}

#else

static inline int qt2160_register_leds(struct qt2160_data *qt2160)
{
	return 0;
}

static inline void qt2160_unregister_leds(struct qt2160_data *qt2160)
{
}

#endif

static bool qt2160_identify(struct i2c_client *client)
{
	int id, ver, rev;

	/* Read Chid ID to check if chip is valid */
	id = qt2160_read(client, QT2160_CMD_CHIPID);
	if (id != QT2160_VALID_CHIPID) {
		dev_err(&client->dev, "ID %d not supported\n", id);
		return false;
	}

	/* Read chip firmware version */
	ver = qt2160_read(client, QT2160_CMD_CODEVER);
	if (ver < 0) {
		dev_err(&client->dev, "could not get firmware version\n");
		return false;
	}

	/* Read chip firmware revision */
	rev = qt2160_read(client, QT2160_CMD_SUBVER);
	if (rev < 0) {
		dev_err(&client->dev, "could not get firmware revision\n");
		return false;
	}

	dev_info(&client->dev, "AT42QT2160 firmware version %d.%d.%d\n",
			ver >> 4, ver & 0xf, rev);

	return true;
}

static int qt2160_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	struct qt2160_data *qt2160;
	struct input_dev *input;
	int i;
	int error;

	/* Check functionality */
	error = i2c_check_functionality(client->adapter,
			I2C_FUNC_SMBUS_BYTE);
	if (!error) {
		dev_err(&client->dev, "%s adapter not supported\n",
				dev_driver_string(&client->adapter->dev));
		return -ENODEV;
	}

	if (!qt2160_identify(client))
		return -ENODEV;

	/* Chip is valid and active. Allocate structure */
	qt2160 = kzalloc(sizeof(struct qt2160_data), GFP_KERNEL);
	input = input_allocate_device();
	if (!qt2160 || !input) {
		dev_err(&client->dev, "insufficient memory\n");
		error = -ENOMEM;
		goto err_free_mem;
	}

	qt2160->client = client;
	qt2160->input = input;
	INIT_DELAYED_WORK(&qt2160->dwork, qt2160_worker);
	spin_lock_init(&qt2160->lock);

	input->name = "AT42QT2160 Touch Sense Keyboard";
	input->id.bustype = BUS_I2C;

	input->keycode = qt2160->keycodes;
	input->keycodesize = sizeof(qt2160->keycodes[0]);
	input->keycodemax = ARRAY_SIZE(qt2160_key2code);

	__set_bit(EV_KEY, input->evbit);
	__clear_bit(EV_REP, input->evbit);
	for (i = 0; i < ARRAY_SIZE(qt2160_key2code); i++) {
		qt2160->keycodes[i] = qt2160_key2code[i];
		__set_bit(qt2160_key2code[i], input->keybit);
	}
	__clear_bit(KEY_RESERVED, input->keybit);

	/* Calibrate device */
	error = qt2160_write(client, QT2160_CMD_CALIBRATE, 1);
	if (error) {
		dev_err(&client->dev, "failed to calibrate device\n");
		goto err_free_mem;
	}

	if (client->irq) {
		error = request_irq(client->irq, qt2160_irq,
				    IRQF_TRIGGER_FALLING, "qt2160", qt2160);
		if (error) {
			dev_err(&client->dev,
				"failed to allocate irq %d\n", client->irq);
			goto err_free_mem;
		}
	}

	error = qt2160_register_leds(qt2160);
	if (error) {
		dev_err(&client->dev, "Failed to register leds\n");
		goto err_free_irq;
	}

	error = input_register_device(qt2160->input);
	if (error) {
		dev_err(&client->dev,
			"Failed to register input device\n");
		goto err_unregister_leds;
	}

	i2c_set_clientdata(client, qt2160);
	qt2160_schedule_read(qt2160);

	return 0;

err_unregister_leds:
	qt2160_unregister_leds(qt2160);
err_free_irq:
	if (client->irq)
		free_irq(client->irq, qt2160);
err_free_mem:
	input_free_device(input);
	kfree(qt2160);
	return error;
}

static int qt2160_remove(struct i2c_client *client)
{
	struct qt2160_data *qt2160 = i2c_get_clientdata(client);

	qt2160_unregister_leds(qt2160);

	/* Release IRQ so no queue will be scheduled */
	if (client->irq)
		free_irq(client->irq, qt2160);

	cancel_delayed_work_sync(&qt2160->dwork);

	input_unregister_device(qt2160->input);
	kfree(qt2160);

	return 0;
}

static const struct i2c_device_id qt2160_idtable[] = {
	{ "qt2160", 0, },
	{ }
};

MODULE_DEVICE_TABLE(i2c, qt2160_idtable);

static struct i2c_driver qt2160_driver = {
	.driver = {
		.name	= "qt2160",
		.owner  = THIS_MODULE,
	},

	.id_table	= qt2160_idtable,
	.probe		= qt2160_probe,
	.remove		= qt2160_remove,
};

module_i2c_driver(qt2160_driver);

MODULE_AUTHOR("Raphael Derosso Pereira <raphaelpereira@gmail.com>");
MODULE_DESCRIPTION("Driver for AT42QT2160 Touch Sensor");
MODULE_LICENSE("GPL");