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fde11323 RDP |
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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
fde11323 RDP |
361 | return 0; |
362 | } | |
363 | ||
ce7b39a1 | 364 | static const struct i2c_device_id qt2160_idtable[] = { |
fde11323 RDP |
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 | ||
1b92c1cf | 382 | module_i2c_driver(qt2160_driver); |
fde11323 RDP |
383 | |
384 | MODULE_AUTHOR("Raphael Derosso Pereira <raphaelpereira@gmail.com>"); | |
385 | MODULE_DESCRIPTION("Driver for AT42QT2160 Touch Sensor"); | |
386 | MODULE_LICENSE("GPL"); |