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 #include <linux/of.h>
  39
  40 /* TCA8418 hardware limits */
  41 #define TCA8418_MAX_ROWS        8
  42 #define TCA8418_MAX_COLS        10
  43
  44 /* TCA8418 register offsets */
  45 #define REG_CFG                 0x01
  46 #define REG_INT_STAT            0x02
  47 #define REG_KEY_LCK_EC          0x03
  48 #define REG_KEY_EVENT_A         0x04
  49 #define REG_KEY_EVENT_B         0x05
  50 #define REG_KEY_EVENT_C         0x06
  51 #define REG_KEY_EVENT_D         0x07
  52 #define REG_KEY_EVENT_E         0x08
  53 #define REG_KEY_EVENT_F         0x09
  54 #define REG_KEY_EVENT_G         0x0A
  55 #define REG_KEY_EVENT_H         0x0B
  56 #define REG_KEY_EVENT_I         0x0C
  57 #define REG_KEY_EVENT_J         0x0D
  58 #define REG_KP_LCK_TIMER        0x0E
  59 #define REG_UNLOCK1             0x0F
  60 #define REG_UNLOCK2             0x10
  61 #define REG_GPIO_INT_STAT1      0x11
  62 #define REG_GPIO_INT_STAT2      0x12
  63 #define REG_GPIO_INT_STAT3      0x13
  64 #define REG_GPIO_DAT_STAT1      0x14
  65 #define REG_GPIO_DAT_STAT2      0x15
  66 #define REG_GPIO_DAT_STAT3      0x16
  67 #define REG_GPIO_DAT_OUT1       0x17
  68 #define REG_GPIO_DAT_OUT2       0x18
  69 #define REG_GPIO_DAT_OUT3       0x19
  70 #define REG_GPIO_INT_EN1        0x1A
  71 #define REG_GPIO_INT_EN2        0x1B
  72 #define REG_GPIO_INT_EN3        0x1C
  73 #define REG_KP_GPIO1            0x1D
  74 #define REG_KP_GPIO2            0x1E
  75 #define REG_KP_GPIO3            0x1F
  76 #define REG_GPI_EM1             0x20
  77 #define REG_GPI_EM2             0x21
  78 #define REG_GPI_EM3             0x22
  79 #define REG_GPIO_DIR1           0x23
  80 #define REG_GPIO_DIR2           0x24
  81 #define REG_GPIO_DIR3           0x25
  82 #define REG_GPIO_INT_LVL1       0x26
  83 #define REG_GPIO_INT_LVL2       0x27
  84 #define REG_GPIO_INT_LVL3       0x28
  85 #define REG_DEBOUNCE_DIS1       0x29
  86 #define REG_DEBOUNCE_DIS2       0x2A
  87 #define REG_DEBOUNCE_DIS3       0x2B
  88 #define REG_GPIO_PULL1          0x2C
  89 #define REG_GPIO_PULL2          0x2D
  90 #define REG_GPIO_PULL3          0x2E
  91
  92 /* TCA8418 bit definitions */
  93 #define CFG_AI                  BIT(7)
  94 #define CFG_GPI_E_CFG           BIT(6)
  95 #define CFG_OVR_FLOW_M          BIT(5)
  96 #define CFG_INT_CFG             BIT(4)
  97 #define CFG_OVR_FLOW_IEN        BIT(3)
  98 #define CFG_K_LCK_IEN           BIT(2)
  99 #define CFG_GPI_IEN             BIT(1)
 100 #define CFG_KE_IEN              BIT(0)
 101
 102 #define INT_STAT_CAD_INT        BIT(4)
 103 #define INT_STAT_OVR_FLOW_INT   BIT(3)
 104 #define INT_STAT_K_LCK_INT      BIT(2)
 105 #define INT_STAT_GPI_INT        BIT(1)
 106 #define INT_STAT_K_INT          BIT(0)
 107
 108 /* TCA8418 register masks */
 109 #define KEY_LCK_EC_KEC          0x7
 110 #define KEY_EVENT_CODE          0x7f
 111 #define KEY_EVENT_VALUE         0x80
 112
 113 struct tca8418_keypad {
 114         struct i2c_client *client;
 115         struct input_dev *input;
 116
 117         unsigned int row_shift;
 118 };
 119
 120 /*
 121  * Write a byte to the TCA8418
 122  */
 123 static int tca8418_write_byte(struct tca8418_keypad *keypad_data,
 124                               int reg, u8 val)
 125 {
 126         int error;
 127
 128         error = i2c_smbus_write_byte_data(keypad_data->client, reg, val);
 129         if (error < 0) {
 130                 dev_err(&keypad_data->client->dev,
 131                         "%s failed, reg: %d, val: %d, error: %d\n",
 132                         __func__, reg, val, error);
 133                 return error;
 134         }
 135
 136         return 0;
 137 }
 138
 139 /*
 140  * Read a byte from the TCA8418
 141  */
 142 static int tca8418_read_byte(struct tca8418_keypad *keypad_data,
 143                              int reg, u8 *val)
 144 {
 145         int error;
 146
 147         error = i2c_smbus_read_byte_data(keypad_data->client, reg);
 148         if (error < 0) {
 149                 dev_err(&keypad_data->client->dev,
 150                                 "%s failed, reg: %d, error: %d\n",
 151                                 __func__, reg, error);
 152                 return error;
 153         }
 154
 155         *val = (u8)error;
 156
 157         return 0;
 158 }
 159
 160 static void tca8418_read_keypad(struct tca8418_keypad *keypad_data)
 161 {
 162         struct input_dev *input = keypad_data->input;
 163         unsigned short *keymap = input->keycode;
 164         int error, col, row;
 165         u8 reg, state, code;
 166
 167         /* Initial read of the key event FIFO */
 168         error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, &reg);
 169
 170         /* Assume that key code 0 signifies empty FIFO */
 171         while (error >= 0 && reg > 0) {
 172                 state = reg & KEY_EVENT_VALUE;
 173                 code  = reg & KEY_EVENT_CODE;
 174
 175                 row = code / TCA8418_MAX_COLS;
 176                 col = code % TCA8418_MAX_COLS;
 177
 178                 row = (col) ? row : row - 1;
 179                 col = (col) ? col - 1 : TCA8418_MAX_COLS - 1;
 180
 181                 code = MATRIX_SCAN_CODE(row, col, keypad_data->row_shift);
 182                 input_event(input, EV_MSC, MSC_SCAN, code);
 183                 input_report_key(input, keymap[code], state);
 184
 185                 /* Read for next loop */
 186                 error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, &reg);
 187         }
 188
 189         if (error < 0)
 190                 dev_err(&keypad_data->client->dev,
 191                         "unable to read REG_KEY_EVENT_A\n");
 192
 193         input_sync(input);
 194 }
 195
 196 /*
 197  * Threaded IRQ handler and this can (and will) sleep.
 198  */
 199 static irqreturn_t tca8418_irq_handler(int irq, void *dev_id)
 200 {
 201         struct tca8418_keypad *keypad_data = dev_id;
 202         u8 reg;
 203         int error;
 204
 205         error = tca8418_read_byte(keypad_data, REG_INT_STAT, &reg);
 206         if (error) {
 207                 dev_err(&keypad_data->client->dev,
 208                         "unable to read REG_INT_STAT\n");
 209                 return IRQ_NONE;
 210         }
 211
 212         if (!reg)
 213                 return IRQ_NONE;
 214
 215         if (reg & INT_STAT_OVR_FLOW_INT)
 216                 dev_warn(&keypad_data->client->dev, "overflow occurred\n");
 217
 218         if (reg & INT_STAT_K_INT)
 219                 tca8418_read_keypad(keypad_data);
 220
 221         /* Clear all interrupts, even IRQs we didn't check (GPI, CAD, LCK) */
 222         reg = 0xff;
 223         error = tca8418_write_byte(keypad_data, REG_INT_STAT, reg);
 224         if (error)
 225                 dev_err(&keypad_data->client->dev,
 226                         "unable to clear REG_INT_STAT\n");
 227
 228         return IRQ_HANDLED;
 229 }
 230
 231 /*
 232  * Configure the TCA8418 for keypad operation
 233  */
 234 static int tca8418_configure(struct tca8418_keypad *keypad_data,
 235                              u32 rows, u32 cols)
 236 {
 237         int reg, error;
 238
 239         /* Write config register, if this fails assume device not present */
 240         error = tca8418_write_byte(keypad_data, REG_CFG,
 241                                 CFG_INT_CFG | CFG_OVR_FLOW_IEN | CFG_KE_IEN);
 242         if (error < 0)
 243                 return -ENODEV;
 244
 245
 246         /* Assemble a mask for row and column registers */
 247         reg  =  ~(~0 << rows);
 248         reg += (~(~0 << cols)) << 8;
 249
 250         /* Set registers to keypad mode */
 251         error |= tca8418_write_byte(keypad_data, REG_KP_GPIO1, reg);
 252         error |= tca8418_write_byte(keypad_data, REG_KP_GPIO2, reg >> 8);
 253         error |= tca8418_write_byte(keypad_data, REG_KP_GPIO3, reg >> 16);
 254
 255         /* Enable column debouncing */
 256         error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS1, reg);
 257         error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS2, reg >> 8);
 258         error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS3, reg >> 16);
 259
 260         return error;
 261 }
 262
 263 static int tca8418_keypad_probe(struct i2c_client *client,
 264                                           const struct i2c_device_id *id)
 265 {
 266         struct device *dev = &client->dev;
 267         const struct tca8418_keypad_platform_data *pdata =
 268                                                 dev_get_platdata(dev);
 269         struct tca8418_keypad *keypad_data;
 270         struct input_dev *input;
 271         const struct matrix_keymap_data *keymap_data = NULL;
 272         u32 rows = 0, cols = 0;
 273         bool rep = false;
 274         bool irq_is_gpio = false;
 275         int irq;
 276         int error, row_shift, max_keys;
 277
 278         /* Copy the platform data */
 279         if (pdata) {
 280                 if (!pdata->keymap_data) {
 281                         dev_err(dev, "no keymap data defined\n");
 282                         return -EINVAL;
 283                 }
 284                 keymap_data = pdata->keymap_data;
 285                 rows = pdata->rows;
 286                 cols = pdata->cols;
 287                 rep  = pdata->rep;
 288                 irq_is_gpio = pdata->irq_is_gpio;
 289         } else {
 290                 struct device_node *np = dev->of_node;
 291                 int err;
 292
 293                 err = matrix_keypad_parse_of_params(dev, &rows, &cols);
 294                 if (err)
 295                         return err;
 296                 rep = of_property_read_bool(np, "keypad,autorepeat");
 297         }
 298
 299         if (!rows || rows > TCA8418_MAX_ROWS) {
 300                 dev_err(dev, "invalid rows\n");
 301                 return -EINVAL;
 302         }
 303
 304         if (!cols || cols > TCA8418_MAX_COLS) {
 305                 dev_err(dev, "invalid columns\n");
 306                 return -EINVAL;
 307         }
 308
 309         /* Check i2c driver capabilities */
 310         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE)) {
 311                 dev_err(dev, "%s adapter not supported\n",
 312                         dev_driver_string(&client->adapter->dev));
 313                 return -ENODEV;
 314         }
 315
 316         row_shift = get_count_order(cols);
 317         max_keys = rows << row_shift;
 318
 319         /* Allocate memory for keypad_data and input device */
 320         keypad_data = devm_kzalloc(dev, sizeof(*keypad_data), GFP_KERNEL);
 321         if (!keypad_data)
 322                 return -ENOMEM;
 323
 324         keypad_data->client = client;
 325         keypad_data->row_shift = row_shift;
 326
 327         /* Initialize the chip or fail if chip isn't present */
 328         error = tca8418_configure(keypad_data, rows, cols);
 329         if (error < 0)
 330                 return error;
 331
 332         /* Configure input device */
 333         input = devm_input_allocate_device(dev);
 334         if (!input)
 335                 return -ENOMEM;
 336
 337         keypad_data->input = input;
 338
 339         input->name = client->name;
 340         input->id.bustype = BUS_I2C;
 341         input->id.vendor  = 0x0001;
 342         input->id.product = 0x001;
 343         input->id.version = 0x0001;
 344
 345         error = matrix_keypad_build_keymap(keymap_data, NULL, rows, cols,
 346                                            NULL, input);
 347         if (error) {
 348                 dev_err(dev, "Failed to build keymap\n");
 349                 return error;
 350         }
 351
 352         if (rep)
 353                 __set_bit(EV_REP, input->evbit);
 354         input_set_capability(input, EV_MSC, MSC_SCAN);
 355
 356         input_set_drvdata(input, keypad_data);
 357
 358         irq = client->irq;
 359         if (irq_is_gpio)
 360                 irq = gpio_to_irq(irq);
 361
 362         error = devm_request_threaded_irq(dev, irq, NULL, tca8418_irq_handler,
 363                                           IRQF_TRIGGER_FALLING |
 364                                                 IRQF_SHARED |
 365                                                 IRQF_ONESHOT,
 366                                           client->name, keypad_data);
 367         if (error) {
 368                 dev_err(dev, "Unable to claim irq %d; error %d\n",
 369                         client->irq, error);
 370                 return error;
 371         }
 372
 373         error = input_register_device(input);
 374         if (error) {
 375                 dev_err(dev, "Unable to register input device, error: %d\n",
 376                         error);
 377                 return error;
 378         }
 379
 380         return 0;
 381 }
 382
 383 static const struct i2c_device_id tca8418_id[] = {
 384         { TCA8418_NAME, 8418, },
 385         { }
 386 };
 387 MODULE_DEVICE_TABLE(i2c, tca8418_id);
 388
 389 #ifdef CONFIG_OF
 390 static const struct of_device_id tca8418_dt_ids[] = {
 391         { .compatible = "ti,tca8418", },
 392         { }
 393 };
 394 MODULE_DEVICE_TABLE(of, tca8418_dt_ids);
 395
 396 /*
 397  * The device tree based i2c loader looks for
 398  * "i2c:" + second_component_of(property("compatible"))
 399  * and therefore we need an alias to be found.
 400  */
 401 MODULE_ALIAS("i2c:tca8418");
 402 #endif
 403
 404 static struct i2c_driver tca8418_keypad_driver = {
 405         .driver = {
 406                 .name   = TCA8418_NAME,
 407                 .of_match_table = of_match_ptr(tca8418_dt_ids),
 408         },
 409         .probe          = tca8418_keypad_probe,
 410         .id_table       = tca8418_id,
 411 };
 412
 413 static int __init tca8418_keypad_init(void)
 414 {
 415         return i2c_add_driver(&tca8418_keypad_driver);
 416 }
 417 subsys_initcall(tca8418_keypad_init);
 418
 419 static void __exit tca8418_keypad_exit(void)
 420 {
 421         i2c_del_driver(&tca8418_keypad_driver);
 422 }
 423 module_exit(tca8418_keypad_exit);
 424
 425 MODULE_AUTHOR("Kyle Manna <kyle.manna@fuel7.com>");
 426 MODULE_DESCRIPTION("Keypad driver for TCA8418");
 427 MODULE_LICENSE("GPL");