drivers/input/keyboard/qt2160.c

   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/leds.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 #define QT2160_CMD_DRIVE_X    70
  43 #define QT2160_CMD_PWMEN_X    74
  44 #define QT2160_CMD_PWM_DUTY   76
  45
  46 #define QT2160_NUM_LEDS_X       8
  47
  48 #define QT2160_CYCLE_INTERVAL   (2*HZ)
  49
  50 static unsigned char qt2160_key2code[] = {
  51         KEY_0, KEY_1, KEY_2, KEY_3,
  52         KEY_4, KEY_5, KEY_6, KEY_7,
  53         KEY_8, KEY_9, KEY_A, KEY_B,
  54         KEY_C, KEY_D, KEY_E, KEY_F,
  55 };
  56
  57 #ifdef CONFIG_LEDS_CLASS
  58 struct qt2160_led {
  59         struct qt2160_data *qt2160;
  60         struct led_classdev cdev;
  61         char name[32];
  62         int id;
  63         enum led_brightness brightness;
  64 };
  65 #endif
  66
  67 struct qt2160_data {
  68         struct i2c_client *client;
  69         struct input_dev *input;
  70         struct delayed_work dwork;
  71         spinlock_t lock;        /* Protects canceling/rescheduling of dwork */
  72         unsigned short keycodes[ARRAY_SIZE(qt2160_key2code)];
  73         u16 key_matrix;
  74 #ifdef CONFIG_LEDS_CLASS
  75         struct qt2160_led leds[QT2160_NUM_LEDS_X];
  76 #endif
  77 };
  78
  79 static int qt2160_read(struct i2c_client *client, u8 reg);
  80 static int qt2160_write(struct i2c_client *client, u8 reg, u8 data);
  81
  82 #ifdef CONFIG_LEDS_CLASS
  83
  84 static int qt2160_led_set(struct led_classdev *cdev,
  85                           enum led_brightness value)
  86 {
  87         struct qt2160_led *led = container_of(cdev, struct qt2160_led, cdev);
  88         struct qt2160_data *qt2160 = led->qt2160;
  89         struct i2c_client *client = qt2160->client;
  90         u32 drive, pwmen;
  91
  92         if (value != led->brightness) {
  93                 drive = qt2160_read(client, QT2160_CMD_DRIVE_X);
  94                 pwmen = qt2160_read(client, QT2160_CMD_PWMEN_X);
  95                 if (value != LED_OFF) {
  96                         drive |= BIT(led->id);
  97                         pwmen |= BIT(led->id);
  98
  99                 } else {
 100                         drive &= ~BIT(led->id);
 101                         pwmen &= ~BIT(led->id);
 102                 }
 103                 qt2160_write(client, QT2160_CMD_DRIVE_X, drive);
 104                 qt2160_write(client, QT2160_CMD_PWMEN_X, pwmen);
 105
 106                 /*
 107                  * Changing this register will change the brightness
 108                  * of every LED in the qt2160. It's a HW limitation.
 109                  */
 110                 if (value != LED_OFF)
 111                         qt2160_write(client, QT2160_CMD_PWM_DUTY, value);
 112
 113                 led->brightness = value;
 114         }
 115
 116         return 0;
 117 }
 118
 119 #endif /* CONFIG_LEDS_CLASS */
 120
 121 static int qt2160_read_block(struct i2c_client *client,
 122                              u8 inireg, u8 *buffer, unsigned int count)
 123 {
 124         int error, idx = 0;
 125
 126         /*
 127          * Can't use SMBus block data read. Check for I2C functionality to speed
 128          * things up whenever possible. Otherwise we will be forced to read
 129          * sequentially.
 130          */
 131         if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C))     {
 132
 133                 error = i2c_smbus_write_byte(client, inireg + idx);
 134                 if (error) {
 135                         dev_err(&client->dev,
 136                                 "couldn't send request. Returned %d\n", error);
 137                         return error;
 138                 }
 139
 140                 error = i2c_master_recv(client, buffer, count);
 141                 if (error != count) {
 142                         dev_err(&client->dev,
 143                                 "couldn't read registers. Returned %d bytes\n", error);
 144                         return error;
 145                 }
 146         } else {
 147
 148                 while (count--) {
 149                         int data;
 150
 151                         error = i2c_smbus_write_byte(client, inireg + idx);
 152                         if (error) {
 153                                 dev_err(&client->dev,
 154                                         "couldn't send request. Returned %d\n", error);
 155                                 return error;
 156                         }
 157
 158                         data = i2c_smbus_read_byte(client);
 159                         if (data < 0) {
 160                                 dev_err(&client->dev,
 161                                         "couldn't read register. Returned %d\n", data);
 162                                 return data;
 163                         }
 164
 165                         buffer[idx++] = data;
 166                 }
 167         }
 168
 169         return 0;
 170 }
 171
 172 static int qt2160_get_key_matrix(struct qt2160_data *qt2160)
 173 {
 174         struct i2c_client *client = qt2160->client;
 175         struct input_dev *input = qt2160->input;
 176         u8 regs[6];
 177         u16 old_matrix, new_matrix;
 178         int ret, i, mask;
 179
 180         dev_dbg(&client->dev, "requesting keys...\n");
 181
 182         /*
 183          * Read all registers from General Status Register
 184          * to GPIOs register
 185          */
 186         ret = qt2160_read_block(client, QT2160_CMD_GSTAT, regs, 6);
 187         if (ret) {
 188                 dev_err(&client->dev,
 189                         "could not perform chip read.\n");
 190                 return ret;
 191         }
 192
 193         old_matrix = qt2160->key_matrix;
 194         qt2160->key_matrix = new_matrix = (regs[2] << 8) | regs[1];
 195
 196         mask = 0x01;
 197         for (i = 0; i < 16; ++i, mask <<= 1) {
 198                 int keyval = new_matrix & mask;
 199
 200                 if ((old_matrix & mask) != keyval) {
 201                         input_report_key(input, qt2160->keycodes[i], keyval);
 202                         dev_dbg(&client->dev, "key %d %s\n",
 203                                 i, keyval ? "pressed" : "released");
 204                 }
 205         }
 206
 207         input_sync(input);
 208
 209         return 0;
 210 }
 211
 212 static irqreturn_t qt2160_irq(int irq, void *_qt2160)
 213 {
 214         struct qt2160_data *qt2160 = _qt2160;
 215         unsigned long flags;
 216
 217         spin_lock_irqsave(&qt2160->lock, flags);
 218
 219         mod_delayed_work(system_wq, &qt2160->dwork, 0);
 220
 221         spin_unlock_irqrestore(&qt2160->lock, flags);
 222
 223         return IRQ_HANDLED;
 224 }
 225
 226 static void qt2160_schedule_read(struct qt2160_data *qt2160)
 227 {
 228         spin_lock_irq(&qt2160->lock);
 229         schedule_delayed_work(&qt2160->dwork, QT2160_CYCLE_INTERVAL);
 230         spin_unlock_irq(&qt2160->lock);
 231 }
 232
 233 static void qt2160_worker(struct work_struct *work)
 234 {
 235         struct qt2160_data *qt2160 =
 236                 container_of(work, struct qt2160_data, dwork.work);
 237
 238         dev_dbg(&qt2160->client->dev, "worker\n");
 239
 240         qt2160_get_key_matrix(qt2160);
 241
 242         /* Avoid device lock up by checking every so often */
 243         qt2160_schedule_read(qt2160);
 244 }
 245
 246 static int qt2160_read(struct i2c_client *client, u8 reg)
 247 {
 248         int ret;
 249
 250         ret = i2c_smbus_write_byte(client, reg);
 251         if (ret) {
 252                 dev_err(&client->dev,
 253                         "couldn't send request. Returned %d\n", ret);
 254                 return ret;
 255         }
 256
 257         ret = i2c_smbus_read_byte(client);
 258         if (ret < 0) {
 259                 dev_err(&client->dev,
 260                         "couldn't read register. Returned %d\n", ret);
 261                 return ret;
 262         }
 263
 264         return ret;
 265 }
 266
 267 static int qt2160_write(struct i2c_client *client, u8 reg, u8 data)
 268 {
 269         int ret;
 270
 271         ret = i2c_smbus_write_byte_data(client, reg, data);
 272         if (ret < 0)
 273                 dev_err(&client->dev,
 274                         "couldn't write data. Returned %d\n", ret);
 275
 276         return ret;
 277 }
 278
 279 #ifdef CONFIG_LEDS_CLASS
 280
 281 static int qt2160_register_leds(struct qt2160_data *qt2160)
 282 {
 283         struct i2c_client *client = qt2160->client;
 284         int ret;
 285         int i;
 286
 287         for (i = 0; i < QT2160_NUM_LEDS_X; i++) {
 288                 struct qt2160_led *led = &qt2160->leds[i];
 289
 290                 snprintf(led->name, sizeof(led->name), "qt2160:x%d", i);
 291                 led->cdev.name = led->name;
 292                 led->cdev.brightness_set_blocking = qt2160_led_set;
 293                 led->cdev.brightness = LED_OFF;
 294                 led->id = i;
 295                 led->qt2160 = qt2160;
 296
 297                 ret = led_classdev_register(&client->dev, &led->cdev);
 298                 if (ret < 0)
 299                         return ret;
 300         }
 301
 302         /* Tur off LEDs */
 303         qt2160_write(client, QT2160_CMD_DRIVE_X, 0);
 304         qt2160_write(client, QT2160_CMD_PWMEN_X, 0);
 305         qt2160_write(client, QT2160_CMD_PWM_DUTY, 0);
 306
 307         return 0;
 308 }
 309
 310 static void qt2160_unregister_leds(struct qt2160_data *qt2160)
 311 {
 312         int i;
 313
 314         for (i = 0; i < QT2160_NUM_LEDS_X; i++)
 315                 led_classdev_unregister(&qt2160->leds[i].cdev);
 316 }
 317
 318 #else
 319
 320 static inline int qt2160_register_leds(struct qt2160_data *qt2160)
 321 {
 322         return 0;
 323 }
 324
 325 static inline void qt2160_unregister_leds(struct qt2160_data *qt2160)
 326 {
 327 }
 328
 329 #endif
 330
 331 static bool qt2160_identify(struct i2c_client *client)
 332 {
 333         int id, ver, rev;
 334
 335         /* Read Chid ID to check if chip is valid */
 336         id = qt2160_read(client, QT2160_CMD_CHIPID);
 337         if (id != QT2160_VALID_CHIPID) {
 338                 dev_err(&client->dev, "ID %d not supported\n", id);
 339                 return false;
 340         }
 341
 342         /* Read chip firmware version */
 343         ver = qt2160_read(client, QT2160_CMD_CODEVER);
 344         if (ver < 0) {
 345                 dev_err(&client->dev, "could not get firmware version\n");
 346                 return false;
 347         }
 348
 349         /* Read chip firmware revision */
 350         rev = qt2160_read(client, QT2160_CMD_SUBVER);
 351         if (rev < 0) {
 352                 dev_err(&client->dev, "could not get firmware revision\n");
 353                 return false;
 354         }
 355
 356         dev_info(&client->dev, "AT42QT2160 firmware version %d.%d.%d\n",
 357                         ver >> 4, ver & 0xf, rev);
 358
 359         return true;
 360 }
 361
 362 static int qt2160_probe(struct i2c_client *client,
 363                         const struct i2c_device_id *id)
 364 {
 365         struct qt2160_data *qt2160;
 366         struct input_dev *input;
 367         int i;
 368         int error;
 369
 370         /* Check functionality */
 371         error = i2c_check_functionality(client->adapter,
 372                         I2C_FUNC_SMBUS_BYTE);
 373         if (!error) {
 374                 dev_err(&client->dev, "%s adapter not supported\n",
 375                                 dev_driver_string(&client->adapter->dev));
 376                 return -ENODEV;
 377         }
 378
 379         if (!qt2160_identify(client))
 380                 return -ENODEV;
 381
 382         /* Chip is valid and active. Allocate structure */
 383         qt2160 = kzalloc(sizeof(struct qt2160_data), GFP_KERNEL);
 384         input = input_allocate_device();
 385         if (!qt2160 || !input) {
 386                 dev_err(&client->dev, "insufficient memory\n");
 387                 error = -ENOMEM;
 388                 goto err_free_mem;
 389         }
 390
 391         qt2160->client = client;
 392         qt2160->input = input;
 393         INIT_DELAYED_WORK(&qt2160->dwork, qt2160_worker);
 394         spin_lock_init(&qt2160->lock);
 395
 396         input->name = "AT42QT2160 Touch Sense Keyboard";
 397         input->id.bustype = BUS_I2C;
 398
 399         input->keycode = qt2160->keycodes;
 400         input->keycodesize = sizeof(qt2160->keycodes[0]);
 401         input->keycodemax = ARRAY_SIZE(qt2160_key2code);
 402
 403         __set_bit(EV_KEY, input->evbit);
 404         __clear_bit(EV_REP, input->evbit);
 405         for (i = 0; i < ARRAY_SIZE(qt2160_key2code); i++) {
 406                 qt2160->keycodes[i] = qt2160_key2code[i];
 407                 __set_bit(qt2160_key2code[i], input->keybit);
 408         }
 409         __clear_bit(KEY_RESERVED, input->keybit);
 410
 411         /* Calibrate device */
 412         error = qt2160_write(client, QT2160_CMD_CALIBRATE, 1);
 413         if (error) {
 414                 dev_err(&client->dev, "failed to calibrate device\n");
 415                 goto err_free_mem;
 416         }
 417
 418         if (client->irq) {
 419                 error = request_irq(client->irq, qt2160_irq,
 420                                     IRQF_TRIGGER_FALLING, "qt2160", qt2160);
 421                 if (error) {
 422                         dev_err(&client->dev,
 423                                 "failed to allocate irq %d\n", client->irq);
 424                         goto err_free_mem;
 425                 }
 426         }
 427
 428         error = qt2160_register_leds(qt2160);
 429         if (error) {
 430                 dev_err(&client->dev, "Failed to register leds\n");
 431                 goto err_free_irq;
 432         }
 433
 434         error = input_register_device(qt2160->input);
 435         if (error) {
 436                 dev_err(&client->dev,
 437                         "Failed to register input device\n");
 438                 goto err_unregister_leds;
 439         }
 440
 441         i2c_set_clientdata(client, qt2160);
 442         qt2160_schedule_read(qt2160);
 443
 444         return 0;
 445
 446 err_unregister_leds:
 447         qt2160_unregister_leds(qt2160);
 448 err_free_irq:
 449         if (client->irq)
 450                 free_irq(client->irq, qt2160);
 451 err_free_mem:
 452         input_free_device(input);
 453         kfree(qt2160);
 454         return error;
 455 }
 456
 457 static int qt2160_remove(struct i2c_client *client)
 458 {
 459         struct qt2160_data *qt2160 = i2c_get_clientdata(client);
 460
 461         qt2160_unregister_leds(qt2160);
 462
 463         /* Release IRQ so no queue will be scheduled */
 464         if (client->irq)
 465                 free_irq(client->irq, qt2160);
 466
 467         cancel_delayed_work_sync(&qt2160->dwork);
 468
 469         input_unregister_device(qt2160->input);
 470         kfree(qt2160);
 471
 472         return 0;
 473 }
 474
 475 static const struct i2c_device_id qt2160_idtable[] = {
 476         { "qt2160", 0, },
 477         { }
 478 };
 479
 480 MODULE_DEVICE_TABLE(i2c, qt2160_idtable);
 481
 482 static struct i2c_driver qt2160_driver = {
 483         .driver = {
 484                 .name   = "qt2160",
 485         },
 486
 487         .id_table       = qt2160_idtable,
 488         .probe          = qt2160_probe,
 489         .remove         = qt2160_remove,
 490 };
 491
 492 module_i2c_driver(qt2160_driver);
 493
 494 MODULE_AUTHOR("Raphael Derosso Pereira <raphaelpereira@gmail.com>");
 495 MODULE_DESCRIPTION("Driver for AT42QT2160 Touch Sensor");
 496 MODULE_LICENSE("GPL");