2 * qt2160.c - Atmel AT42QT2160 Touch Sense Controller
4 * Copyright (C) 2009 Raphael Derosso Pereira <raphaelpereira@gmail.com>
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.
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.
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.
21 #include <linux/kernel.h>
22 #include <linux/leds.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>
31 #define QT2160_VALID_CHIPID 0x11
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 #define QT2160_CMD_DRIVE_X 70
43 #define QT2160_CMD_PWMEN_X 74
44 #define QT2160_CMD_PWM_DUTY 76
46 #define QT2160_NUM_LEDS_X 8
48 #define QT2160_CYCLE_INTERVAL (2*HZ)
50 static unsigned char qt2160_key2code
[] = {
51 KEY_0
, KEY_1
, KEY_2
, KEY_3
,
52 KEY_4
, KEY_5
, KEY_6
, KEY_7
,
53 KEY_8
, KEY_9
, KEY_A
, KEY_B
,
54 KEY_C
, KEY_D
, KEY_E
, KEY_F
,
57 #ifdef CONFIG_LEDS_CLASS
59 struct qt2160_data
*qt2160
;
60 struct led_classdev cdev
;
63 enum led_brightness brightness
;
68 struct i2c_client
*client
;
69 struct input_dev
*input
;
70 struct delayed_work dwork
;
71 spinlock_t lock
; /* Protects canceling/rescheduling of dwork */
72 unsigned short keycodes
[ARRAY_SIZE(qt2160_key2code
)];
74 #ifdef CONFIG_LEDS_CLASS
75 struct qt2160_led leds
[QT2160_NUM_LEDS_X
];
79 static int qt2160_read(struct i2c_client
*client
, u8 reg
);
80 static int qt2160_write(struct i2c_client
*client
, u8 reg
, u8 data
);
82 #ifdef CONFIG_LEDS_CLASS
84 static int qt2160_led_set(struct led_classdev
*cdev
,
85 enum led_brightness value
)
87 struct qt2160_led
*led
= container_of(cdev
, struct qt2160_led
, cdev
);
88 struct qt2160_data
*qt2160
= led
->qt2160
;
89 struct i2c_client
*client
= qt2160
->client
;
92 if (value
!= led
->brightness
) {
93 drive
= qt2160_read(client
, QT2160_CMD_DRIVE_X
);
94 pwmen
= qt2160_read(client
, QT2160_CMD_PWMEN_X
);
95 if (value
!= LED_OFF
) {
96 drive
|= BIT(led
->id
);
97 pwmen
|= BIT(led
->id
);
100 drive
&= ~BIT(led
->id
);
101 pwmen
&= ~BIT(led
->id
);
103 qt2160_write(client
, QT2160_CMD_DRIVE_X
, drive
);
104 qt2160_write(client
, QT2160_CMD_PWMEN_X
, pwmen
);
107 * Changing this register will change the brightness
108 * of every LED in the qt2160. It's a HW limitation.
110 if (value
!= LED_OFF
)
111 qt2160_write(client
, QT2160_CMD_PWM_DUTY
, value
);
113 led
->brightness
= value
;
119 #endif /* CONFIG_LEDS_CLASS */
121 static int qt2160_read_block(struct i2c_client
*client
,
122 u8 inireg
, u8
*buffer
, unsigned int count
)
127 * Can't use SMBus block data read. Check for I2C functionality to speed
128 * things up whenever possible. Otherwise we will be forced to read
131 if (i2c_check_functionality(client
->adapter
, I2C_FUNC_I2C
)) {
133 error
= i2c_smbus_write_byte(client
, inireg
+ idx
);
135 dev_err(&client
->dev
,
136 "couldn't send request. Returned %d\n", error
);
140 error
= i2c_master_recv(client
, buffer
, count
);
141 if (error
!= count
) {
142 dev_err(&client
->dev
,
143 "couldn't read registers. Returned %d bytes\n", error
);
151 error
= i2c_smbus_write_byte(client
, inireg
+ idx
);
153 dev_err(&client
->dev
,
154 "couldn't send request. Returned %d\n", error
);
158 data
= i2c_smbus_read_byte(client
);
160 dev_err(&client
->dev
,
161 "couldn't read register. Returned %d\n", data
);
165 buffer
[idx
++] = data
;
172 static int qt2160_get_key_matrix(struct qt2160_data
*qt2160
)
174 struct i2c_client
*client
= qt2160
->client
;
175 struct input_dev
*input
= qt2160
->input
;
177 u16 old_matrix
, new_matrix
;
180 dev_dbg(&client
->dev
, "requesting keys...\n");
183 * Read all registers from General Status Register
186 ret
= qt2160_read_block(client
, QT2160_CMD_GSTAT
, regs
, 6);
188 dev_err(&client
->dev
,
189 "could not perform chip read.\n");
193 old_matrix
= qt2160
->key_matrix
;
194 qt2160
->key_matrix
= new_matrix
= (regs
[2] << 8) | regs
[1];
197 for (i
= 0; i
< 16; ++i
, mask
<<= 1) {
198 int keyval
= new_matrix
& mask
;
200 if ((old_matrix
& mask
) != keyval
) {
201 input_report_key(input
, qt2160
->keycodes
[i
], keyval
);
202 dev_dbg(&client
->dev
, "key %d %s\n",
203 i
, keyval
? "pressed" : "released");
212 static irqreturn_t
qt2160_irq(int irq
, void *_qt2160
)
214 struct qt2160_data
*qt2160
= _qt2160
;
217 spin_lock_irqsave(&qt2160
->lock
, flags
);
219 mod_delayed_work(system_wq
, &qt2160
->dwork
, 0);
221 spin_unlock_irqrestore(&qt2160
->lock
, flags
);
226 static void qt2160_schedule_read(struct qt2160_data
*qt2160
)
228 spin_lock_irq(&qt2160
->lock
);
229 schedule_delayed_work(&qt2160
->dwork
, QT2160_CYCLE_INTERVAL
);
230 spin_unlock_irq(&qt2160
->lock
);
233 static void qt2160_worker(struct work_struct
*work
)
235 struct qt2160_data
*qt2160
=
236 container_of(work
, struct qt2160_data
, dwork
.work
);
238 dev_dbg(&qt2160
->client
->dev
, "worker\n");
240 qt2160_get_key_matrix(qt2160
);
242 /* Avoid device lock up by checking every so often */
243 qt2160_schedule_read(qt2160
);
246 static int qt2160_read(struct i2c_client
*client
, u8 reg
)
250 ret
= i2c_smbus_write_byte(client
, reg
);
252 dev_err(&client
->dev
,
253 "couldn't send request. Returned %d\n", ret
);
257 ret
= i2c_smbus_read_byte(client
);
259 dev_err(&client
->dev
,
260 "couldn't read register. Returned %d\n", ret
);
267 static int qt2160_write(struct i2c_client
*client
, u8 reg
, u8 data
)
271 ret
= i2c_smbus_write_byte_data(client
, reg
, data
);
273 dev_err(&client
->dev
,
274 "couldn't write data. Returned %d\n", ret
);
279 #ifdef CONFIG_LEDS_CLASS
281 static int qt2160_register_leds(struct qt2160_data
*qt2160
)
283 struct i2c_client
*client
= qt2160
->client
;
287 for (i
= 0; i
< QT2160_NUM_LEDS_X
; i
++) {
288 struct qt2160_led
*led
= &qt2160
->leds
[i
];
290 snprintf(led
->name
, sizeof(led
->name
), "qt2160:x%d", i
);
291 led
->cdev
.name
= led
->name
;
292 led
->cdev
.brightness_set_blocking
= qt2160_led_set
;
293 led
->cdev
.brightness
= LED_OFF
;
295 led
->qt2160
= qt2160
;
297 ret
= led_classdev_register(&client
->dev
, &led
->cdev
);
303 qt2160_write(client
, QT2160_CMD_DRIVE_X
, 0);
304 qt2160_write(client
, QT2160_CMD_PWMEN_X
, 0);
305 qt2160_write(client
, QT2160_CMD_PWM_DUTY
, 0);
310 static void qt2160_unregister_leds(struct qt2160_data
*qt2160
)
314 for (i
= 0; i
< QT2160_NUM_LEDS_X
; i
++)
315 led_classdev_unregister(&qt2160
->leds
[i
].cdev
);
320 static inline int qt2160_register_leds(struct qt2160_data
*qt2160
)
325 static inline void qt2160_unregister_leds(struct qt2160_data
*qt2160
)
331 static bool qt2160_identify(struct i2c_client
*client
)
335 /* Read Chid ID to check if chip is valid */
336 id
= qt2160_read(client
, QT2160_CMD_CHIPID
);
337 if (id
!= QT2160_VALID_CHIPID
) {
338 dev_err(&client
->dev
, "ID %d not supported\n", id
);
342 /* Read chip firmware version */
343 ver
= qt2160_read(client
, QT2160_CMD_CODEVER
);
345 dev_err(&client
->dev
, "could not get firmware version\n");
349 /* Read chip firmware revision */
350 rev
= qt2160_read(client
, QT2160_CMD_SUBVER
);
352 dev_err(&client
->dev
, "could not get firmware revision\n");
356 dev_info(&client
->dev
, "AT42QT2160 firmware version %d.%d.%d\n",
357 ver
>> 4, ver
& 0xf, rev
);
362 static int qt2160_probe(struct i2c_client
*client
,
363 const struct i2c_device_id
*id
)
365 struct qt2160_data
*qt2160
;
366 struct input_dev
*input
;
370 /* Check functionality */
371 error
= i2c_check_functionality(client
->adapter
,
372 I2C_FUNC_SMBUS_BYTE
);
374 dev_err(&client
->dev
, "%s adapter not supported\n",
375 dev_driver_string(&client
->adapter
->dev
));
379 if (!qt2160_identify(client
))
382 /* Chip is valid and active. Allocate structure */
383 qt2160
= kzalloc(sizeof(struct qt2160_data
), GFP_KERNEL
);
384 input
= input_allocate_device();
385 if (!qt2160
|| !input
) {
386 dev_err(&client
->dev
, "insufficient memory\n");
391 qt2160
->client
= client
;
392 qt2160
->input
= input
;
393 INIT_DELAYED_WORK(&qt2160
->dwork
, qt2160_worker
);
394 spin_lock_init(&qt2160
->lock
);
396 input
->name
= "AT42QT2160 Touch Sense Keyboard";
397 input
->id
.bustype
= BUS_I2C
;
399 input
->keycode
= qt2160
->keycodes
;
400 input
->keycodesize
= sizeof(qt2160
->keycodes
[0]);
401 input
->keycodemax
= ARRAY_SIZE(qt2160_key2code
);
403 __set_bit(EV_KEY
, input
->evbit
);
404 __clear_bit(EV_REP
, input
->evbit
);
405 for (i
= 0; i
< ARRAY_SIZE(qt2160_key2code
); i
++) {
406 qt2160
->keycodes
[i
] = qt2160_key2code
[i
];
407 __set_bit(qt2160_key2code
[i
], input
->keybit
);
409 __clear_bit(KEY_RESERVED
, input
->keybit
);
411 /* Calibrate device */
412 error
= qt2160_write(client
, QT2160_CMD_CALIBRATE
, 1);
414 dev_err(&client
->dev
, "failed to calibrate device\n");
419 error
= request_irq(client
->irq
, qt2160_irq
,
420 IRQF_TRIGGER_FALLING
, "qt2160", qt2160
);
422 dev_err(&client
->dev
,
423 "failed to allocate irq %d\n", client
->irq
);
428 error
= qt2160_register_leds(qt2160
);
430 dev_err(&client
->dev
, "Failed to register leds\n");
434 error
= input_register_device(qt2160
->input
);
436 dev_err(&client
->dev
,
437 "Failed to register input device\n");
438 goto err_unregister_leds
;
441 i2c_set_clientdata(client
, qt2160
);
442 qt2160_schedule_read(qt2160
);
447 qt2160_unregister_leds(qt2160
);
450 free_irq(client
->irq
, qt2160
);
452 input_free_device(input
);
457 static int qt2160_remove(struct i2c_client
*client
)
459 struct qt2160_data
*qt2160
= i2c_get_clientdata(client
);
461 qt2160_unregister_leds(qt2160
);
463 /* Release IRQ so no queue will be scheduled */
465 free_irq(client
->irq
, qt2160
);
467 cancel_delayed_work_sync(&qt2160
->dwork
);
469 input_unregister_device(qt2160
->input
);
475 static const struct i2c_device_id qt2160_idtable
[] = {
480 MODULE_DEVICE_TABLE(i2c
, qt2160_idtable
);
482 static struct i2c_driver qt2160_driver
= {
487 .id_table
= qt2160_idtable
,
488 .probe
= qt2160_probe
,
489 .remove
= qt2160_remove
,
492 module_i2c_driver(qt2160_driver
);
494 MODULE_AUTHOR("Raphael Derosso Pereira <raphaelpereira@gmail.com>");
495 MODULE_DESCRIPTION("Driver for AT42QT2160 Touch Sensor");
496 MODULE_LICENSE("GPL");