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/delay.h>
  28 #include <linux/i2c.h>
  29 #include <linux/init.h>
  30 #include <linux/input.h>
  31 #include <linux/input/matrix_keypad.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/module.h>
  34 #include <linux/of.h>
  35 #include <linux/property.h>
  36 #include <linux/slab.h>
  37 #include <linux/types.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 struct tca8418_keypad {
 113         struct i2c_client *client;
 114         struct input_dev *input;
 115
 116         unsigned int row_shift;
 117 };
 118
 119 /*
 120  * Write a byte to the TCA8418
 121  */
 122 static int tca8418_write_byte(struct tca8418_keypad *keypad_data,
 123                               int reg, u8 val)
 124 {
 125         int error;
 126
 127         error = i2c_smbus_write_byte_data(keypad_data->client, reg, val);
 128         if (error < 0) {
 129                 dev_err(&keypad_data->client->dev,
 130                         "%s failed, reg: %d, val: %d, error: %d\n",
 131                         __func__, reg, val, error);
 132                 return error;
 133         }
 134
 135         return 0;
 136 }
 137
 138 /*
 139  * Read a byte from the TCA8418
 140  */
 141 static int tca8418_read_byte(struct tca8418_keypad *keypad_data,
 142                              int reg, u8 *val)
 143 {
 144         int error;
 145
 146         error = i2c_smbus_read_byte_data(keypad_data->client, reg);
 147         if (error < 0) {
 148                 dev_err(&keypad_data->client->dev,
 149                                 "%s failed, reg: %d, error: %d\n",
 150                                 __func__, reg, error);
 151                 return error;
 152         }
 153
 154         *val = (u8)error;
 155
 156         return 0;
 157 }
 158
 159 static void tca8418_read_keypad(struct tca8418_keypad *keypad_data)
 160 {
 161         struct input_dev *input = keypad_data->input;
 162         unsigned short *keymap = input->keycode;
 163         int error, col, row;
 164         u8 reg, state, code;
 165
 166         do {
 167                 error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, &reg);
 168                 if (error < 0) {
 169                         dev_err(&keypad_data->client->dev,
 170                                 "unable to read REG_KEY_EVENT_A\n");
 171                         break;
 172                 }
 173
 174                 /* Assume that key code 0 signifies empty FIFO */
 175                 if (reg <= 0)
 176                         break;
 177
 178                 state = reg & KEY_EVENT_VALUE;
 179                 code  = reg & KEY_EVENT_CODE;
 180
 181                 row = code / TCA8418_MAX_COLS;
 182                 col = code % TCA8418_MAX_COLS;
 183
 184                 row = (col) ? row : row - 1;
 185                 col = (col) ? col - 1 : TCA8418_MAX_COLS - 1;
 186
 187                 code = MATRIX_SCAN_CODE(row, col, keypad_data->row_shift);
 188                 input_event(input, EV_MSC, MSC_SCAN, code);
 189                 input_report_key(input, keymap[code], state);
 190
 191         } while (1);
 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 = 0;
 238
 239         /* Assemble a mask for row and column registers */
 240         reg  =  ~(~0 << rows);
 241         reg += (~(~0 << cols)) << 8;
 242
 243         /* Set registers to keypad mode */
 244         error |= tca8418_write_byte(keypad_data, REG_KP_GPIO1, reg);
 245         error |= tca8418_write_byte(keypad_data, REG_KP_GPIO2, reg >> 8);
 246         error |= tca8418_write_byte(keypad_data, REG_KP_GPIO3, reg >> 16);
 247
 248         /* Enable column debouncing */
 249         error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS1, reg);
 250         error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS2, reg >> 8);
 251         error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS3, reg >> 16);
 252
 253         if (error)
 254                 return error;
 255
 256         error = tca8418_write_byte(keypad_data, REG_CFG,
 257                                 CFG_INT_CFG | CFG_OVR_FLOW_IEN | CFG_KE_IEN);
 258
 259         return error;
 260 }
 261
 262 static int tca8418_keypad_probe(struct i2c_client *client,
 263                                 const struct i2c_device_id *id)
 264 {
 265         struct device *dev = &client->dev;
 266         struct tca8418_keypad *keypad_data;
 267         struct input_dev *input;
 268         u32 rows = 0, cols = 0;
 269         int error, row_shift, max_keys;
 270         u8 reg;
 271
 272         /* Check i2c driver capabilities */
 273         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE)) {
 274                 dev_err(dev, "%s adapter not supported\n",
 275                         dev_driver_string(&client->adapter->dev));
 276                 return -ENODEV;
 277         }
 278
 279         error = matrix_keypad_parse_properties(dev, &rows, &cols);
 280         if (error)
 281                 return error;
 282
 283         if (!rows || rows > TCA8418_MAX_ROWS) {
 284                 dev_err(dev, "invalid rows\n");
 285                 return -EINVAL;
 286         }
 287
 288         if (!cols || cols > TCA8418_MAX_COLS) {
 289                 dev_err(dev, "invalid columns\n");
 290                 return -EINVAL;
 291         }
 292
 293         row_shift = get_count_order(cols);
 294         max_keys = rows << row_shift;
 295
 296         /* Allocate memory for keypad_data and input device */
 297         keypad_data = devm_kzalloc(dev, sizeof(*keypad_data), GFP_KERNEL);
 298         if (!keypad_data)
 299                 return -ENOMEM;
 300
 301         keypad_data->client = client;
 302         keypad_data->row_shift = row_shift;
 303
 304         /* Read key lock register, if this fails assume device not present */
 305         error = tca8418_read_byte(keypad_data, REG_KEY_LCK_EC, &reg);
 306         if (error)
 307                 return -ENODEV;
 308
 309         /* Configure input device */
 310         input = devm_input_allocate_device(dev);
 311         if (!input)
 312                 return -ENOMEM;
 313
 314         keypad_data->input = input;
 315
 316         input->name = client->name;
 317         input->id.bustype = BUS_I2C;
 318         input->id.vendor  = 0x0001;
 319         input->id.product = 0x001;
 320         input->id.version = 0x0001;
 321
 322         error = matrix_keypad_build_keymap(NULL, NULL, rows, cols, NULL, input);
 323         if (error) {
 324                 dev_err(dev, "Failed to build keymap\n");
 325                 return error;
 326         }
 327
 328         if (device_property_read_bool(dev, "keypad,autorepeat"))
 329                 __set_bit(EV_REP, input->evbit);
 330
 331         input_set_capability(input, EV_MSC, MSC_SCAN);
 332
 333         error = devm_request_threaded_irq(dev, client->irq,
 334                                           NULL, tca8418_irq_handler,
 335                                           IRQF_SHARED | IRQF_ONESHOT,
 336                                           client->name, keypad_data);
 337         if (error) {
 338                 dev_err(dev, "Unable to claim irq %d; error %d\n",
 339                         client->irq, error);
 340                 return error;
 341         }
 342
 343         /* Initialize the chip */
 344         error = tca8418_configure(keypad_data, rows, cols);
 345         if (error < 0)
 346                 return error;
 347
 348         error = input_register_device(input);
 349         if (error) {
 350                 dev_err(dev, "Unable to register input device, error: %d\n",
 351                         error);
 352                 return error;
 353         }
 354
 355         return 0;
 356 }
 357
 358 static const struct i2c_device_id tca8418_id[] = {
 359         { "tca8418", 8418, },
 360         { }
 361 };
 362 MODULE_DEVICE_TABLE(i2c, tca8418_id);
 363
 364 static const struct of_device_id tca8418_dt_ids[] = {
 365         { .compatible = "ti,tca8418", },
 366         { }
 367 };
 368 MODULE_DEVICE_TABLE(of, tca8418_dt_ids);
 369
 370 static struct i2c_driver tca8418_keypad_driver = {
 371         .driver = {
 372                 .name   = "tca8418_keypad",
 373                 .of_match_table = tca8418_dt_ids,
 374         },
 375         .probe          = tca8418_keypad_probe,
 376         .id_table       = tca8418_id,
 377 };
 378
 379 static int __init tca8418_keypad_init(void)
 380 {
 381         return i2c_add_driver(&tca8418_keypad_driver);
 382 }
 383 subsys_initcall(tca8418_keypad_init);
 384
 385 static void __exit tca8418_keypad_exit(void)
 386 {
 387         i2c_del_driver(&tca8418_keypad_driver);
 388 }
 389 module_exit(tca8418_keypad_exit);
 390
 391 MODULE_AUTHOR("Kyle Manna <kyle.manna@fuel7.com>");
 392 MODULE_DESCRIPTION("Keypad driver for TCA8418");
 393 MODULE_LICENSE("GPL");