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 ret; 211 212 ret = i2c_smbus_write_byte_data(client, reg, data); 213 if (ret < 0) 214 dev_err(&client->dev, 215 "couldn't write data. Returned %d\n", ret); 216 217 return ret; 218 } 219 220 221 static bool __devinit qt2160_identify(struct i2c_client *client) 222 { 223 int id, ver, rev; 224 225 /* Read Chid ID to check if chip is valid */ 226 id = qt2160_read(client, QT2160_CMD_CHIPID); 227 if (id != QT2160_VALID_CHIPID) { 228 dev_err(&client->dev, "ID %d not supported\n", id); 229 return false; 230 } 231 232 /* Read chip firmware version */ 233 ver = qt2160_read(client, QT2160_CMD_CODEVER); 234 if (ver < 0) { 235 dev_err(&client->dev, "could not get firmware version\n"); 236 return false; 237 } 238 239 /* Read chip firmware revision */ 240 rev = qt2160_read(client, QT2160_CMD_SUBVER); 241 if (rev < 0) { 242 dev_err(&client->dev, "could not get firmware revision\n"); 243 return false; 244 } 245 246 dev_info(&client->dev, "AT42QT2160 firmware version %d.%d.%d\n", 247 ver >> 4, ver & 0xf, rev); 248 249 return true; 250 } 251 252 static int __devinit qt2160_probe(struct i2c_client *client, 253 const struct i2c_device_id *id) 254 { 255 struct qt2160_data *qt2160; 256 struct input_dev *input; 257 int i; 258 int error; 259 260 /* Check functionality */ 261 error = i2c_check_functionality(client->adapter, 262 I2C_FUNC_SMBUS_BYTE); 263 if (!error) { 264 dev_err(&client->dev, "%s adapter not supported\n", 265 dev_driver_string(&client->adapter->dev)); 266 return -ENODEV; 267 } 268 269 if (!qt2160_identify(client)) 270 return -ENODEV; 271 272 /* Chip is valid and active. Allocate structure */ 273 qt2160 = kzalloc(sizeof(struct qt2160_data), GFP_KERNEL); 274 input = input_allocate_device(); 275 if (!qt2160 || !input) { 276 dev_err(&client->dev, "insufficient memory\n"); 277 error = -ENOMEM; 278 goto err_free_mem; 279 } 280 281 qt2160->client = client; 282 qt2160->input = input; 283 INIT_DELAYED_WORK(&qt2160->dwork, qt2160_worker); 284 spin_lock_init(&qt2160->lock); 285 286 input->name = "AT42QT2160 Touch Sense Keyboard"; 287 input->id.bustype = BUS_I2C; 288 289 input->keycode = qt2160->keycodes; 290 input->keycodesize = sizeof(qt2160->keycodes[0]); 291 input->keycodemax = ARRAY_SIZE(qt2160_key2code); 292 293 __set_bit(EV_KEY, input->evbit); 294 __clear_bit(EV_REP, input->evbit); 295 for (i = 0; i < ARRAY_SIZE(qt2160_key2code); i++) { 296 qt2160->keycodes[i] = qt2160_key2code[i]; 297 __set_bit(qt2160_key2code[i], input->keybit); 298 } 299 __clear_bit(KEY_RESERVED, input->keybit); 300 301 /* Calibrate device */ 302 error = qt2160_write(client, QT2160_CMD_CALIBRATE, 1); 303 if (error) { 304 dev_err(&client->dev, "failed to calibrate device\n"); 305 goto err_free_mem; 306 } 307 308 if (client->irq) { 309 error = request_irq(client->irq, qt2160_irq, 310 IRQF_TRIGGER_FALLING, "qt2160", qt2160); 311 if (error) { 312 dev_err(&client->dev, 313 "failed to allocate irq %d\n", client->irq); 314 goto err_free_mem; 315 } 316 } 317 318 error = input_register_device(qt2160->input); 319 if (error) { 320 dev_err(&client->dev, 321 "Failed to register input device\n"); 322 goto err_free_irq; 323 } 324 325 i2c_set_clientdata(client, qt2160); 326 qt2160_schedule_read(qt2160); 327 328 return 0; 329 330 err_free_irq: 331 if (client->irq) 332 free_irq(client->irq, qt2160); 333 err_free_mem: 334 input_free_device(input); 335 kfree(qt2160); 336 return error; 337 } 338 339 static int __devexit qt2160_remove(struct i2c_client *client) 340 { 341 struct qt2160_data *qt2160 = i2c_get_clientdata(client); 342 343 /* Release IRQ so no queue will be scheduled */ 344 if (client->irq) 345 free_irq(client->irq, qt2160); 346 347 cancel_delayed_work_sync(&qt2160->dwork); 348 349 input_unregister_device(qt2160->input); 350 kfree(qt2160); 351 352 return 0; 353 } 354 355 static const struct i2c_device_id qt2160_idtable[] = { 356 { "qt2160", 0, }, 357 { } 358 }; 359 360 MODULE_DEVICE_TABLE(i2c, qt2160_idtable); 361 362 static struct i2c_driver qt2160_driver = { 363 .driver = { 364 .name = "qt2160", 365 .owner = THIS_MODULE, 366 }, 367 368 .id_table = qt2160_idtable, 369 .probe = qt2160_probe, 370 .remove = __devexit_p(qt2160_remove), 371 }; 372 373 module_i2c_driver(qt2160_driver); 374 375 MODULE_AUTHOR("Raphael Derosso Pereira <raphaelpereira@gmail.com>"); 376 MODULE_DESCRIPTION("Driver for AT42QT2160 Touch Sensor"); 377 MODULE_LICENSE("GPL"); 378