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 45static 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 52struct 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 61static 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 112static 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 152static 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 167static 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 174static 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 187static 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 208static 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 230static 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 261static 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 339err_free_irq: 340 if (client->irq) 341 free_irq(client->irq, qt2160); 342err_free_mem: 343 input_free_device(input); 344 kfree(qt2160); 345 return error; 346} 347 348static 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 364static const struct i2c_device_id qt2160_idtable[] = { 365 { "qt2160", 0, }, 366 { } 367}; 368 369MODULE_DEVICE_TABLE(i2c, qt2160_idtable); 370 371static 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 382static int __init qt2160_init(void) 383{ 384 return i2c_add_driver(&qt2160_driver); 385} 386module_init(qt2160_init); 387 388static void __exit qt2160_cleanup(void) 389{ 390 i2c_del_driver(&qt2160_driver); 391} 392module_exit(qt2160_cleanup); 393 394MODULE_AUTHOR("Raphael Derosso Pereira <raphaelpereira@gmail.com>"); 395MODULE_DESCRIPTION("Driver for AT42QT2160 Touch Sensor"); 396MODULE_LICENSE("GPL"); 397