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, ®); 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, ®); 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, ®); 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 error = matrix_keypad_build_keymap(pdata->keymap_data, NULL, 346 pdata->rows, pdata->cols, 347 keypad_data->keymap, input); 348 if (error) { 349 dev_dbg(&client->dev, "Failed to build keymap\n"); 350 goto fail2; 351 } 352 353 if (pdata->rep) 354 __set_bit(EV_REP, input->evbit); 355 input_set_capability(input, EV_MSC, MSC_SCAN); 356 357 input_set_drvdata(input, keypad_data); 358 359 if (pdata->irq_is_gpio) 360 client->irq = gpio_to_irq(client->irq); 361 362 error = request_threaded_irq(client->irq, NULL, tca8418_irq_handler, 363 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, 364 client->name, keypad_data); 365 if (error) { 366 dev_dbg(&client->dev, 367 "Unable to claim irq %d; error %d\n", 368 client->irq, error); 369 goto fail2; 370 } 371 372 error = input_register_device(input); 373 if (error) { 374 dev_dbg(&client->dev, 375 "Unable to register input device, error: %d\n", error); 376 goto fail3; 377 } 378 379 i2c_set_clientdata(client, keypad_data); 380 return 0; 381 382 fail3: 383 free_irq(client->irq, keypad_data); 384 fail2: 385 input_free_device(input); 386 fail1: 387 kfree(keypad_data); 388 return error; 389 } 390 391 static int __devexit tca8418_keypad_remove(struct i2c_client *client) 392 { 393 struct tca8418_keypad *keypad_data = i2c_get_clientdata(client); 394 395 free_irq(keypad_data->client->irq, keypad_data); 396 397 input_unregister_device(keypad_data->input); 398 399 kfree(keypad_data); 400 401 return 0; 402 } 403 404 405 static struct i2c_driver tca8418_keypad_driver = { 406 .driver = { 407 .name = TCA8418_NAME, 408 .owner = THIS_MODULE, 409 }, 410 .probe = tca8418_keypad_probe, 411 .remove = __devexit_p(tca8418_keypad_remove), 412 .id_table = tca8418_id, 413 }; 414 415 static int __init tca8418_keypad_init(void) 416 { 417 return i2c_add_driver(&tca8418_keypad_driver); 418 } 419 subsys_initcall(tca8418_keypad_init); 420 421 static void __exit tca8418_keypad_exit(void) 422 { 423 i2c_del_driver(&tca8418_keypad_driver); 424 } 425 module_exit(tca8418_keypad_exit); 426 427 MODULE_AUTHOR("Kyle Manna <kyle.manna@fuel7.com>"); 428 MODULE_DESCRIPTION("Keypad driver for TCA8418"); 429 MODULE_LICENSE("GPL"); 430