drivers/input/keyboard/tca8418_keypad.c

   1 /*
   2  * Driver for TCA8418 I2C keyboard
   3  *
   4  * Copyright (C) 2011 Fuel7, Inc.  All rights reserved.
   5  *
   6  * Author: Kyle Manna <kyle.manna@fuel7.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public
  10  * License v2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public
  18  * License along with this program; if not, write to the
  19  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20  * Boston, MA 021110-1307, USA.
  21  *
  22  * If you can't comply with GPLv2, alternative licensing terms may be
  23  * arranged. Please contact Fuel7, Inc. (http://fuel7.com/) for proprietary
  24  * alternative licensing inquiries.
  25  */
  26
  27 #include <linux/types.h>
  28 #include <linux/module.h>
  29 #include <linux/init.h>
  30 #include <linux/delay.h>
  31 #include <linux/slab.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/workqueue.h>
  34 #include <linux/gpio.h>
  35 #include <linux/i2c.h>
  36 #include <linux/input.h>
  37 #include <linux/input/tca8418_keypad.h>
  38
  39 /* TCA8418 hardware limits */
  40 #define TCA8418_MAX_ROWS        8
  41 #define TCA8418_MAX_COLS        10
  42
  43 /* TCA8418 register offsets */
  44 #define REG_CFG                 0x01
  45 #define REG_INT_STAT            0x02
  46 #define REG_KEY_LCK_EC          0x03
  47 #define REG_KEY_EVENT_A         0x04
  48 #define REG_KEY_EVENT_B         0x05
  49 #define REG_KEY_EVENT_C         0x06
  50 #define REG_KEY_EVENT_D         0x07
  51 #define REG_KEY_EVENT_E         0x08
  52 #define REG_KEY_EVENT_F         0x09
  53 #define REG_KEY_EVENT_G         0x0A
  54 #define REG_KEY_EVENT_H         0x0B
  55 #define REG_KEY_EVENT_I         0x0C
  56 #define REG_KEY_EVENT_J         0x0D
  57 #define REG_KP_LCK_TIMER        0x0E
  58 #define REG_UNLOCK1             0x0F
  59 #define REG_UNLOCK2             0x10
  60 #define REG_GPIO_INT_STAT1      0x11
  61 #define REG_GPIO_INT_STAT2      0x12
  62 #define REG_GPIO_INT_STAT3      0x13
  63 #define REG_GPIO_DAT_STAT1      0x14
  64 #define REG_GPIO_DAT_STAT2      0x15
  65 #define REG_GPIO_DAT_STAT3      0x16
  66 #define REG_GPIO_DAT_OUT1       0x17
  67 #define REG_GPIO_DAT_OUT2       0x18
  68 #define REG_GPIO_DAT_OUT3       0x19
  69 #define REG_GPIO_INT_EN1        0x1A
  70 #define REG_GPIO_INT_EN2        0x1B
  71 #define REG_GPIO_INT_EN3        0x1C
  72 #define REG_KP_GPIO1            0x1D
  73 #define REG_KP_GPIO2            0x1E
  74 #define REG_KP_GPIO3            0x1F
  75 #define REG_GPI_EM1             0x20
  76 #define REG_GPI_EM2             0x21
  77 #define REG_GPI_EM3             0x22
  78 #define REG_GPIO_DIR1           0x23
  79 #define REG_GPIO_DIR2           0x24
  80 #define REG_GPIO_DIR3           0x25
  81 #define REG_GPIO_INT_LVL1       0x26
  82 #define REG_GPIO_INT_LVL2       0x27
  83 #define REG_GPIO_INT_LVL3       0x28
  84 #define REG_DEBOUNCE_DIS1       0x29
  85 #define REG_DEBOUNCE_DIS2       0x2A
  86 #define REG_DEBOUNCE_DIS3       0x2B
  87 #define REG_GPIO_PULL1          0x2C
  88 #define REG_GPIO_PULL2          0x2D
  89 #define REG_GPIO_PULL3          0x2E
  90
  91 /* TCA8418 bit definitions */
  92 #define CFG_AI                  BIT(7)
  93 #define CFG_GPI_E_CFG           BIT(6)
  94 #define CFG_OVR_FLOW_M          BIT(5)
  95 #define CFG_INT_CFG             BIT(4)
  96 #define CFG_OVR_FLOW_IEN        BIT(3)
  97 #define CFG_K_LCK_IEN           BIT(2)
  98 #define CFG_GPI_IEN             BIT(1)
  99 #define CFG_KE_IEN              BIT(0)
 100
 101 #define INT_STAT_CAD_INT        BIT(4)
 102 #define INT_STAT_OVR_FLOW_INT   BIT(3)
 103 #define INT_STAT_K_LCK_INT      BIT(2)
 104 #define INT_STAT_GPI_INT        BIT(1)
 105 #define INT_STAT_K_INT          BIT(0)
 106
 107 /* TCA8418 register masks */
 108 #define KEY_LCK_EC_KEC          0x7
 109 #define KEY_EVENT_CODE          0x7f
 110 #define KEY_EVENT_VALUE         0x80
 111
 112
 113 static const struct i2c_device_id tca8418_id[] = {
 114         { TCA8418_NAME, 8418, },
 115         { }
 116 };
 117 MODULE_DEVICE_TABLE(i2c, tca8418_id);
 118
 119 struct tca8418_keypad {
 120         unsigned int rows;
 121         unsigned int cols;
 122         unsigned int keypad_mask; /* Mask for keypad col/rol regs */
 123         unsigned int irq;
 124         unsigned int row_shift;
 125
 126         struct i2c_client *client;
 127         struct input_dev *input;
 128
 129         /* Flexible array member, must be at end of struct */
 130         unsigned short keymap[];
 131 };
 132
 133 /*
 134  * Write a byte to the TCA8418
 135  */
 136 static int tca8418_write_byte(struct tca8418_keypad *keypad_data,
 137                               int reg, u8 val)
 138 {
 139         int error;
 140
 141         error = i2c_smbus_write_byte_data(keypad_data->client, reg, val);
 142         if (error < 0) {
 143                 dev_err(&keypad_data->client->dev,
 144                         "%s failed, reg: %d, val: %d, error: %d\n",
 145                         __func__, reg, val, error);
 146                 return error;
 147         }
 148
 149         return 0;
 150 }
 151
 152 /*
 153  * Read a byte from the TCA8418
 154  */
 155 static int tca8418_read_byte(struct tca8418_keypad *keypad_data,
 156                              int reg, u8 *val)
 157 {
 158         int error;
 159
 160         error = i2c_smbus_read_byte_data(keypad_data->client, reg);
 161         if (error < 0) {
 162                 dev_err(&keypad_data->client->dev,
 163                                 "%s failed, reg: %d, error: %d\n",
 164                                 __func__, reg, error);
 165                 return error;
 166         }
 167
 168         *val = (u8)error;
 169
 170         return 0;
 171 }
 172
 173 static void tca8418_read_keypad(struct tca8418_keypad *keypad_data)
 174 {
 175         int error, col, row;
 176         u8 reg, state, code;
 177
 178         /* Initial read of the key event FIFO */
 179         error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, &reg);
 180
 181         /* Assume that key code 0 signifies empty FIFO */
 182         while (error >= 0 && reg > 0) {
 183                 state = reg & KEY_EVENT_VALUE;
 184                 code  = reg & KEY_EVENT_CODE;
 185
 186                 row = code / TCA8418_MAX_COLS;
 187                 col = code % TCA8418_MAX_COLS;
 188
 189                 row = (col) ? row : row - 1;
 190                 col = (col) ? col - 1 : TCA8418_MAX_COLS - 1;
 191
 192                 code = MATRIX_SCAN_CODE(row, col, keypad_data->row_shift);
 193                 input_event(keypad_data->input, EV_MSC, MSC_SCAN, code);
 194                 input_report_key(keypad_data->input,
 195                                 keypad_data->keymap[code], state);
 196
 197                 /* Read for next loop */
 198                 error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, &reg);
 199         }
 200
 201         if (error < 0)
 202                 dev_err(&keypad_data->client->dev,
 203                         "unable to read REG_KEY_EVENT_A\n");
 204
 205         input_sync(keypad_data->input);
 206 }
 207
 208 /*
 209  * Threaded IRQ handler and this can (and will) sleep.
 210  */
 211 static irqreturn_t tca8418_irq_handler(int irq, void *dev_id)
 212 {
 213         struct tca8418_keypad *keypad_data = dev_id;
 214         u8 reg;
 215         int error;
 216
 217         error = tca8418_read_byte(keypad_data, REG_INT_STAT, &reg);
 218         if (error) {
 219                 dev_err(&keypad_data->client->dev,
 220                         "unable to read REG_INT_STAT\n");
 221                 goto exit;
 222         }
 223
 224         if (reg & INT_STAT_OVR_FLOW_INT)
 225                 dev_warn(&keypad_data->client->dev, "overflow occurred\n");
 226
 227         if (reg & INT_STAT_K_INT)
 228                 tca8418_read_keypad(keypad_data);
 229
 230 exit:
 231         /* Clear all interrupts, even IRQs we didn't check (GPI, CAD, LCK) */
 232         reg = 0xff;
 233         error = tca8418_write_byte(keypad_data, REG_INT_STAT, reg);
 234         if (error)
 235                 dev_err(&keypad_data->client->dev,
 236                         "unable to clear REG_INT_STAT\n");
 237
 238         return IRQ_HANDLED;
 239 }
 240
 241 /*
 242  * Configure the TCA8418 for keypad operation
 243  */
 244 static int __devinit tca8418_configure(struct tca8418_keypad *keypad_data)
 245 {
 246         int reg, error;
 247
 248         /* Write config register, if this fails assume device not present */
 249         error = tca8418_write_byte(keypad_data, REG_CFG,
 250                                 CFG_INT_CFG | CFG_OVR_FLOW_IEN | CFG_KE_IEN);
 251         if (error < 0)
 252                 return -ENODEV;
 253
 254
 255         /* Assemble a mask for row and column registers */
 256         reg  =  ~(~0 << keypad_data->rows);
 257         reg += (~(~0 << keypad_data->cols)) << 8;
 258         keypad_data->keypad_mask = reg;
 259
 260         /* Set registers to keypad mode */
 261         error |= tca8418_write_byte(keypad_data, REG_KP_GPIO1, reg);
 262         error |= tca8418_write_byte(keypad_data, REG_KP_GPIO2, reg >> 8);
 263         error |= tca8418_write_byte(keypad_data, REG_KP_GPIO3, reg >> 16);
 264
 265         /* Enable column debouncing */
 266         error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS1, reg);
 267         error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS2, reg >> 8);
 268         error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS3, reg >> 16);
 269
 270         return error;
 271 }
 272
 273 static int __devinit tca8418_keypad_probe(struct i2c_client *client,
 274                                           const struct i2c_device_id *id)
 275 {
 276         const struct tca8418_keypad_platform_data *pdata =
 277                                                 client->dev.platform_data;
 278         struct tca8418_keypad *keypad_data;
 279         struct input_dev *input;
 280         int error, row_shift, max_keys;
 281
 282         /* Copy the platform data */
 283         if (!pdata) {
 284                 dev_dbg(&client->dev, "no platform data\n");
 285                 return -EINVAL;
 286         }
 287
 288         if (!pdata->keymap_data) {
 289                 dev_err(&client->dev, "no keymap data defined\n");
 290                 return -EINVAL;
 291         }
 292
 293         if (!pdata->rows || pdata->rows > TCA8418_MAX_ROWS) {
 294                 dev_err(&client->dev, "invalid rows\n");
 295                 return -EINVAL;
 296         }
 297
 298         if (!pdata->cols || pdata->cols > TCA8418_MAX_COLS) {
 299                 dev_err(&client->dev, "invalid columns\n");
 300                 return -EINVAL;
 301         }
 302
 303         /* Check i2c driver capabilities */
 304         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE)) {
 305                 dev_err(&client->dev, "%s adapter not supported\n",
 306                         dev_driver_string(&client->adapter->dev));
 307                 return -ENODEV;
 308         }
 309
 310         row_shift = get_count_order(pdata->cols);
 311         max_keys = pdata->rows << row_shift;
 312
 313         /* Allocate memory for keypad_data, keymap and input device */
 314         keypad_data = kzalloc(sizeof(*keypad_data) +
 315                         max_keys * sizeof(keypad_data->keymap[0]), GFP_KERNEL);
 316         if (!keypad_data)
 317                 return -ENOMEM;
 318
 319         keypad_data->rows = pdata->rows;
 320         keypad_data->cols = pdata->cols;
 321         keypad_data->client = client;
 322         keypad_data->row_shift = row_shift;
 323
 324         /* Initialize the chip or fail if chip isn't present */
 325         error = tca8418_configure(keypad_data);
 326         if (error < 0)
 327                 goto fail1;
 328
 329         /* Configure input device */
 330         input = input_allocate_device();
 331         if (!input) {
 332                 error = -ENOMEM;
 333                 goto fail1;
 334         }
 335         keypad_data->input = input;
 336
 337         input->name = client->name;
 338         input->dev.parent = &client->dev;
 339
 340         input->id.bustype = BUS_I2C;
 341         input->id.vendor  = 0x0001;
 342         input->id.product = 0x001;
 343         input->id.version = 0x0001;
 344
 345         input->keycode     = keypad_data->keymap;
 346         input->keycodesize = sizeof(keypad_data->keymap[0]);
 347         input->keycodemax  = max_keys;
 348
 349         __set_bit(EV_KEY, input->evbit);
 350         if (pdata->rep)
 351                 __set_bit(EV_REP, input->evbit);
 352
 353         input_set_capability(input, EV_MSC, MSC_SCAN);
 354
 355         input_set_drvdata(input, keypad_data);
 356
 357         matrix_keypad_build_keymap(pdata->keymap_data, row_shift,
 358                         input->keycode, input->keybit);
 359
 360         if (pdata->irq_is_gpio)
 361                 client->irq = gpio_to_irq(client->irq);
 362
 363         error = request_threaded_irq(client->irq, NULL, tca8418_irq_handler,
 364                                      IRQF_TRIGGER_FALLING,
 365                                      client->name, keypad_data);
 366         if (error) {
 367                 dev_dbg(&client->dev,
 368                         "Unable to claim irq %d; error %d\n",
 369                         client->irq, error);
 370                 goto fail2;
 371         }
 372
 373         error = input_register_device(input);
 374         if (error) {
 375                 dev_dbg(&client->dev,
 376                         "Unable to register input device, error: %d\n", error);
 377                 goto fail3;
 378         }
 379
 380         i2c_set_clientdata(client, keypad_data);
 381         return 0;
 382
 383 fail3:
 384         free_irq(client->irq, keypad_data);
 385 fail2:
 386         input_free_device(input);
 387 fail1:
 388         kfree(keypad_data);
 389         return error;
 390 }
 391
 392 static int __devexit tca8418_keypad_remove(struct i2c_client *client)
 393 {
 394         struct tca8418_keypad *keypad_data = i2c_get_clientdata(client);
 395
 396         free_irq(keypad_data->client->irq, keypad_data);
 397
 398         input_unregister_device(keypad_data->input);
 399
 400         kfree(keypad_data);
 401
 402         return 0;
 403 }
 404
 405
 406 static struct i2c_driver tca8418_keypad_driver = {
 407         .driver = {
 408                 .name   = TCA8418_NAME,
 409                 .owner  = THIS_MODULE,
 410         },
 411         .probe          = tca8418_keypad_probe,
 412         .remove         = __devexit_p(tca8418_keypad_remove),
 413         .id_table       = tca8418_id,
 414 };
 415
 416 static int __init tca8418_keypad_init(void)
 417 {
 418         return i2c_add_driver(&tca8418_keypad_driver);
 419 }
 420 subsys_initcall(tca8418_keypad_init);
 421
 422 static void __exit tca8418_keypad_exit(void)
 423 {
 424         i2c_del_driver(&tca8418_keypad_driver);
 425 }
 426 module_exit(tca8418_keypad_exit);
 427
 428 MODULE_AUTHOR("Kyle Manna <kyle.manna@fuel7.com>");
 429 MODULE_DESCRIPTION("Keypad driver for TCA8418");
 430 MODULE_LICENSE("GPL");