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/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>
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
43 #define QT2160_CYCLE_INTERVAL (2*HZ)
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
,
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
)];
61 static int qt2160_read_block(struct i2c_client
*client
,
62 u8 inireg
, u8
*buffer
, unsigned int count
)
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
71 if (i2c_check_functionality(client
->adapter
, I2C_FUNC_I2C
)) {
73 error
= i2c_smbus_write_byte(client
, inireg
+ idx
);
76 "couldn't send request. Returned %d\n", error
);
80 error
= i2c_master_recv(client
, buffer
, count
);
83 "couldn't read registers. Returned %d bytes\n", error
);
91 error
= i2c_smbus_write_byte(client
, inireg
+ idx
);
94 "couldn't send request. Returned %d\n", error
);
98 data
= i2c_smbus_read_byte(client
);
100 dev_err(&client
->dev
,
101 "couldn't read register. Returned %d\n", data
);
105 buffer
[idx
++] = data
;
112 static int qt2160_get_key_matrix(struct qt2160_data
*qt2160
)
114 struct i2c_client
*client
= qt2160
->client
;
115 struct input_dev
*input
= qt2160
->input
;
117 u16 old_matrix
, new_matrix
;
120 dev_dbg(&client
->dev
, "requesting keys...\n");
123 * Read all registers from General Status Register
126 ret
= qt2160_read_block(client
, QT2160_CMD_GSTAT
, regs
, 6);
128 dev_err(&client
->dev
,
129 "could not perform chip read.\n");
133 old_matrix
= qt2160
->key_matrix
;
134 qt2160
->key_matrix
= new_matrix
= (regs
[2] << 8) | regs
[1];
137 for (i
= 0; i
< 16; ++i
, mask
<<= 1) {
138 int keyval
= new_matrix
& mask
;
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");
152 static irqreturn_t
qt2160_irq(int irq
, void *_qt2160
)
154 struct qt2160_data
*qt2160
= _qt2160
;
157 spin_lock_irqsave(&qt2160
->lock
, flags
);
159 mod_delayed_work(system_wq
, &qt2160
->dwork
, 0);
161 spin_unlock_irqrestore(&qt2160
->lock
, flags
);
166 static void qt2160_schedule_read(struct qt2160_data
*qt2160
)
168 spin_lock_irq(&qt2160
->lock
);
169 schedule_delayed_work(&qt2160
->dwork
, QT2160_CYCLE_INTERVAL
);
170 spin_unlock_irq(&qt2160
->lock
);
173 static void qt2160_worker(struct work_struct
*work
)
175 struct qt2160_data
*qt2160
=
176 container_of(work
, struct qt2160_data
, dwork
.work
);
178 dev_dbg(&qt2160
->client
->dev
, "worker\n");
180 qt2160_get_key_matrix(qt2160
);
182 /* Avoid device lock up by checking every so often */
183 qt2160_schedule_read(qt2160
);
186 static int __devinit
qt2160_read(struct i2c_client
*client
, u8 reg
)
190 ret
= i2c_smbus_write_byte(client
, reg
);
192 dev_err(&client
->dev
,
193 "couldn't send request. Returned %d\n", ret
);
197 ret
= i2c_smbus_read_byte(client
);
199 dev_err(&client
->dev
,
200 "couldn't read register. Returned %d\n", ret
);
207 static int __devinit
qt2160_write(struct i2c_client
*client
, u8 reg
, u8 data
)
211 error
= i2c_smbus_write_byte(client
, reg
);
213 dev_err(&client
->dev
,
214 "couldn't send request. Returned %d\n", error
);
218 error
= i2c_smbus_write_byte(client
, data
);
220 dev_err(&client
->dev
,
221 "couldn't write data. Returned %d\n", error
);
229 static bool __devinit
qt2160_identify(struct i2c_client
*client
)
233 /* Read Chid ID to check if chip is valid */
234 id
= qt2160_read(client
, QT2160_CMD_CHIPID
);
235 if (id
!= QT2160_VALID_CHIPID
) {
236 dev_err(&client
->dev
, "ID %d not supported\n", id
);
240 /* Read chip firmware version */
241 ver
= qt2160_read(client
, QT2160_CMD_CODEVER
);
243 dev_err(&client
->dev
, "could not get firmware version\n");
247 /* Read chip firmware revision */
248 rev
= qt2160_read(client
, QT2160_CMD_SUBVER
);
250 dev_err(&client
->dev
, "could not get firmware revision\n");
254 dev_info(&client
->dev
, "AT42QT2160 firmware version %d.%d.%d\n",
255 ver
>> 4, ver
& 0xf, rev
);
260 static int __devinit
qt2160_probe(struct i2c_client
*client
,
261 const struct i2c_device_id
*id
)
263 struct qt2160_data
*qt2160
;
264 struct input_dev
*input
;
268 /* Check functionality */
269 error
= i2c_check_functionality(client
->adapter
,
270 I2C_FUNC_SMBUS_BYTE
);
272 dev_err(&client
->dev
, "%s adapter not supported\n",
273 dev_driver_string(&client
->adapter
->dev
));
277 if (!qt2160_identify(client
))
280 /* Chip is valid and active. Allocate structure */
281 qt2160
= kzalloc(sizeof(struct qt2160_data
), GFP_KERNEL
);
282 input
= input_allocate_device();
283 if (!qt2160
|| !input
) {
284 dev_err(&client
->dev
, "insufficient memory\n");
289 qt2160
->client
= client
;
290 qt2160
->input
= input
;
291 INIT_DELAYED_WORK(&qt2160
->dwork
, qt2160_worker
);
292 spin_lock_init(&qt2160
->lock
);
294 input
->name
= "AT42QT2160 Touch Sense Keyboard";
295 input
->id
.bustype
= BUS_I2C
;
297 input
->keycode
= qt2160
->keycodes
;
298 input
->keycodesize
= sizeof(qt2160
->keycodes
[0]);
299 input
->keycodemax
= ARRAY_SIZE(qt2160_key2code
);
301 __set_bit(EV_KEY
, input
->evbit
);
302 __clear_bit(EV_REP
, input
->evbit
);
303 for (i
= 0; i
< ARRAY_SIZE(qt2160_key2code
); i
++) {
304 qt2160
->keycodes
[i
] = qt2160_key2code
[i
];
305 __set_bit(qt2160_key2code
[i
], input
->keybit
);
307 __clear_bit(KEY_RESERVED
, input
->keybit
);
309 /* Calibrate device */
310 error
= qt2160_write(client
, QT2160_CMD_CALIBRATE
, 1);
312 dev_err(&client
->dev
, "failed to calibrate device\n");
317 error
= request_irq(client
->irq
, qt2160_irq
,
318 IRQF_TRIGGER_FALLING
, "qt2160", qt2160
);
320 dev_err(&client
->dev
,
321 "failed to allocate irq %d\n", client
->irq
);
326 error
= input_register_device(qt2160
->input
);
328 dev_err(&client
->dev
,
329 "Failed to register input device\n");
333 i2c_set_clientdata(client
, qt2160
);
334 qt2160_schedule_read(qt2160
);
340 free_irq(client
->irq
, qt2160
);
342 input_free_device(input
);
347 static int __devexit
qt2160_remove(struct i2c_client
*client
)
349 struct qt2160_data
*qt2160
= i2c_get_clientdata(client
);
351 /* Release IRQ so no queue will be scheduled */
353 free_irq(client
->irq
, qt2160
);
355 cancel_delayed_work_sync(&qt2160
->dwork
);
357 input_unregister_device(qt2160
->input
);
363 static const struct i2c_device_id qt2160_idtable
[] = {
368 MODULE_DEVICE_TABLE(i2c
, qt2160_idtable
);
370 static struct i2c_driver qt2160_driver
= {
373 .owner
= THIS_MODULE
,
376 .id_table
= qt2160_idtable
,
377 .probe
= qt2160_probe
,
378 .remove
= __devexit_p(qt2160_remove
),
381 module_i2c_driver(qt2160_driver
);
383 MODULE_AUTHOR("Raphael Derosso Pereira <raphaelpereira@gmail.com>");
384 MODULE_DESCRIPTION("Driver for AT42QT2160 Touch Sensor");
385 MODULE_LICENSE("GPL");