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 mod_delayed_work(system_wq, &qt2160->dwork, 0); 160 161 spin_unlock_irqrestore(&qt2160->lock, flags); 162 163 return IRQ_HANDLED; 164 } 165 166 static void qt2160_schedule_read(struct qt2160_data *qt2160) 167 { 168 spin_lock_irq(&qt2160->lock); 169 schedule_delayed_work(&qt2160->dwork, QT2160_CYCLE_INTERVAL); 170 spin_unlock_irq(&qt2160->lock); 171 } 172 173 static void qt2160_worker(struct work_struct *work) 174 { 175 struct qt2160_data *qt2160 = 176 container_of(work, struct qt2160_data, dwork.work); 177 178 dev_dbg(&qt2160->client->dev, "worker\n"); 179 180 qt2160_get_key_matrix(qt2160); 181 182 /* Avoid device lock up by checking every so often */ 183 qt2160_schedule_read(qt2160); 184 } 185 186 static int __devinit qt2160_read(struct i2c_client *client, u8 reg) 187 { 188 int ret; 189 190 ret = i2c_smbus_write_byte(client, reg); 191 if (ret) { 192 dev_err(&client->dev, 193 "couldn't send request. Returned %d\n", ret); 194 return ret; 195 } 196 197 ret = i2c_smbus_read_byte(client); 198 if (ret < 0) { 199 dev_err(&client->dev, 200 "couldn't read register. Returned %d\n", ret); 201 return ret; 202 } 203 204 return ret; 205 } 206 207 static int __devinit qt2160_write(struct i2c_client *client, u8 reg, u8 data) 208 { 209 int error; 210 211 error = i2c_smbus_write_byte(client, reg); 212 if (error) { 213 dev_err(&client->dev, 214 "couldn't send request. Returned %d\n", error); 215 return error; 216 } 217 218 error = i2c_smbus_write_byte(client, data); 219 if (error) { 220 dev_err(&client->dev, 221 "couldn't write data. Returned %d\n", error); 222 return error; 223 } 224 225 return error; 226 } 227 228 229 static bool __devinit qt2160_identify(struct i2c_client *client) 230 { 231 int id, ver, rev; 232 233 /* 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); 237 return false; 238 } 239 240 /* Read chip firmware version */ 241 ver = qt2160_read(client, QT2160_CMD_CODEVER); 242 if (ver < 0) { 243 dev_err(&client->dev, "could not get firmware version\n"); 244 return false; 245 } 246 247 /* Read chip firmware revision */ 248 rev = qt2160_read(client, QT2160_CMD_SUBVER); 249 if (rev < 0) { 250 dev_err(&client->dev, "could not get firmware revision\n"); 251 return false; 252 } 253 254 dev_info(&client->dev, "AT42QT2160 firmware version %d.%d.%d\n", 255 ver >> 4, ver & 0xf, rev); 256 257 return true; 258 } 259 260 static int __devinit qt2160_probe(struct i2c_client *client, 261 const struct i2c_device_id *id) 262 { 263 struct qt2160_data *qt2160; 264 struct input_dev *input; 265 int i; 266 int error; 267 268 /* Check functionality */ 269 error = i2c_check_functionality(client->adapter, 270 I2C_FUNC_SMBUS_BYTE); 271 if (!error) { 272 dev_err(&client->dev, "%s adapter not supported\n", 273 dev_driver_string(&client->adapter->dev)); 274 return -ENODEV; 275 } 276 277 if (!qt2160_identify(client)) 278 return -ENODEV; 279 280 /* 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"); 285 error = -ENOMEM; 286 goto err_free_mem; 287 } 288 289 qt2160->client = client; 290 qt2160->input = input; 291 INIT_DELAYED_WORK(&qt2160->dwork, qt2160_worker); 292 spin_lock_init(&qt2160->lock); 293 294 input->name = "AT42QT2160 Touch Sense Keyboard"; 295 input->id.bustype = BUS_I2C; 296 297 input->keycode = qt2160->keycodes; 298 input->keycodesize = sizeof(qt2160->keycodes[0]); 299 input->keycodemax = ARRAY_SIZE(qt2160_key2code); 300 301 __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); 306 } 307 __clear_bit(KEY_RESERVED, input->keybit); 308 309 /* Calibrate device */ 310 error = qt2160_write(client, QT2160_CMD_CALIBRATE, 1); 311 if (error) { 312 dev_err(&client->dev, "failed to calibrate device\n"); 313 goto err_free_mem; 314 } 315 316 if (client->irq) { 317 error = request_irq(client->irq, qt2160_irq, 318 IRQF_TRIGGER_FALLING, "qt2160", qt2160); 319 if (error) { 320 dev_err(&client->dev, 321 "failed to allocate irq %d\n", client->irq); 322 goto err_free_mem; 323 } 324 } 325 326 error = input_register_device(qt2160->input); 327 if (error) { 328 dev_err(&client->dev, 329 "Failed to register input device\n"); 330 goto err_free_irq; 331 } 332 333 i2c_set_clientdata(client, qt2160); 334 qt2160_schedule_read(qt2160); 335 336 return 0; 337 338 err_free_irq: 339 if (client->irq) 340 free_irq(client->irq, qt2160); 341 err_free_mem: 342 input_free_device(input); 343 kfree(qt2160); 344 return error; 345 } 346 347 static int __devexit qt2160_remove(struct i2c_client *client) 348 { 349 struct qt2160_data *qt2160 = i2c_get_clientdata(client); 350 351 /* Release IRQ so no queue will be scheduled */ 352 if (client->irq) 353 free_irq(client->irq, qt2160); 354 355 cancel_delayed_work_sync(&qt2160->dwork); 356 357 input_unregister_device(qt2160->input); 358 kfree(qt2160); 359 360 return 0; 361 } 362 363 static const struct i2c_device_id qt2160_idtable[] = { 364 { "qt2160", 0, }, 365 { } 366 }; 367 368 MODULE_DEVICE_TABLE(i2c, qt2160_idtable); 369 370 static struct i2c_driver qt2160_driver = { 371 .driver = { 372 .name = "qt2160", 373 .owner = THIS_MODULE, 374 }, 375 376 .id_table = qt2160_idtable, 377 .probe = qt2160_probe, 378 .remove = __devexit_p(qt2160_remove), 379 }; 380 381 module_i2c_driver(qt2160_driver); 382 383 MODULE_AUTHOR("Raphael Derosso Pereira <raphaelpereira@gmail.com>"); 384 MODULE_DESCRIPTION("Driver for AT42QT2160 Touch Sensor"); 385 MODULE_LICENSE("GPL"); 386