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 do { 168 error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, ®); 169 if (error < 0) { 170 dev_err(&keypad_data->client->dev, 171 "unable to read REG_KEY_EVENT_A\n"); 172 break; 173 } 174 175 /* Assume that key code 0 signifies empty FIFO */ 176 if (reg <= 0) 177 break; 178 179 state = reg & KEY_EVENT_VALUE; 180 code = reg & KEY_EVENT_CODE; 181 182 row = code / TCA8418_MAX_COLS; 183 col = code % TCA8418_MAX_COLS; 184 185 row = (col) ? row : row - 1; 186 col = (col) ? col - 1 : TCA8418_MAX_COLS - 1; 187 188 code = MATRIX_SCAN_CODE(row, col, keypad_data->row_shift); 189 input_event(input, EV_MSC, MSC_SCAN, code); 190 input_report_key(input, keymap[code], state); 191 192 /* Read for next loop */ 193 error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, ®); 194 } while (1); 195 196 input_sync(input); 197 } 198 199 /* 200 * Threaded IRQ handler and this can (and will) sleep. 201 */ 202 static irqreturn_t tca8418_irq_handler(int irq, void *dev_id) 203 { 204 struct tca8418_keypad *keypad_data = dev_id; 205 u8 reg; 206 int error; 207 208 error = tca8418_read_byte(keypad_data, REG_INT_STAT, ®); 209 if (error) { 210 dev_err(&keypad_data->client->dev, 211 "unable to read REG_INT_STAT\n"); 212 return IRQ_NONE; 213 } 214 215 if (!reg) 216 return IRQ_NONE; 217 218 if (reg & INT_STAT_OVR_FLOW_INT) 219 dev_warn(&keypad_data->client->dev, "overflow occurred\n"); 220 221 if (reg & INT_STAT_K_INT) 222 tca8418_read_keypad(keypad_data); 223 224 /* Clear all interrupts, even IRQs we didn't check (GPI, CAD, LCK) */ 225 reg = 0xff; 226 error = tca8418_write_byte(keypad_data, REG_INT_STAT, reg); 227 if (error) 228 dev_err(&keypad_data->client->dev, 229 "unable to clear REG_INT_STAT\n"); 230 231 return IRQ_HANDLED; 232 } 233 234 /* 235 * Configure the TCA8418 for keypad operation 236 */ 237 static int tca8418_configure(struct tca8418_keypad *keypad_data, 238 u32 rows, u32 cols) 239 { 240 int reg, error; 241 242 /* Write config register, if this fails assume device not present */ 243 error = tca8418_write_byte(keypad_data, REG_CFG, 244 CFG_INT_CFG | CFG_OVR_FLOW_IEN | CFG_KE_IEN); 245 if (error < 0) 246 return -ENODEV; 247 248 249 /* Assemble a mask for row and column registers */ 250 reg = ~(~0 << rows); 251 reg += (~(~0 << cols)) << 8; 252 253 /* Set registers to keypad mode */ 254 error |= tca8418_write_byte(keypad_data, REG_KP_GPIO1, reg); 255 error |= tca8418_write_byte(keypad_data, REG_KP_GPIO2, reg >> 8); 256 error |= tca8418_write_byte(keypad_data, REG_KP_GPIO3, reg >> 16); 257 258 /* Enable column debouncing */ 259 error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS1, reg); 260 error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS2, reg >> 8); 261 error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS3, reg >> 16); 262 263 return error; 264 } 265 266 static int tca8418_keypad_probe(struct i2c_client *client, 267 const struct i2c_device_id *id) 268 { 269 struct device *dev = &client->dev; 270 const struct tca8418_keypad_platform_data *pdata = 271 dev_get_platdata(dev); 272 struct tca8418_keypad *keypad_data; 273 struct input_dev *input; 274 const struct matrix_keymap_data *keymap_data = NULL; 275 u32 rows = 0, cols = 0; 276 bool rep = false; 277 bool irq_is_gpio = false; 278 int irq; 279 int error, row_shift, max_keys; 280 281 /* Copy the platform data */ 282 if (pdata) { 283 if (!pdata->keymap_data) { 284 dev_err(dev, "no keymap data defined\n"); 285 return -EINVAL; 286 } 287 keymap_data = pdata->keymap_data; 288 rows = pdata->rows; 289 cols = pdata->cols; 290 rep = pdata->rep; 291 irq_is_gpio = pdata->irq_is_gpio; 292 } else { 293 struct device_node *np = dev->of_node; 294 int err; 295 296 err = matrix_keypad_parse_of_params(dev, &rows, &cols); 297 if (err) 298 return err; 299 rep = of_property_read_bool(np, "keypad,autorepeat"); 300 } 301 302 if (!rows || rows > TCA8418_MAX_ROWS) { 303 dev_err(dev, "invalid rows\n"); 304 return -EINVAL; 305 } 306 307 if (!cols || cols > TCA8418_MAX_COLS) { 308 dev_err(dev, "invalid columns\n"); 309 return -EINVAL; 310 } 311 312 /* Check i2c driver capabilities */ 313 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE)) { 314 dev_err(dev, "%s adapter not supported\n", 315 dev_driver_string(&client->adapter->dev)); 316 return -ENODEV; 317 } 318 319 row_shift = get_count_order(cols); 320 max_keys = rows << row_shift; 321 322 /* Allocate memory for keypad_data and input device */ 323 keypad_data = devm_kzalloc(dev, sizeof(*keypad_data), GFP_KERNEL); 324 if (!keypad_data) 325 return -ENOMEM; 326 327 keypad_data->client = client; 328 keypad_data->row_shift = row_shift; 329 330 /* Initialize the chip or fail if chip isn't present */ 331 error = tca8418_configure(keypad_data, rows, cols); 332 if (error < 0) 333 return error; 334 335 /* Configure input device */ 336 input = devm_input_allocate_device(dev); 337 if (!input) 338 return -ENOMEM; 339 340 keypad_data->input = input; 341 342 input->name = client->name; 343 input->id.bustype = BUS_I2C; 344 input->id.vendor = 0x0001; 345 input->id.product = 0x001; 346 input->id.version = 0x0001; 347 348 error = matrix_keypad_build_keymap(keymap_data, NULL, rows, cols, 349 NULL, input); 350 if (error) { 351 dev_err(dev, "Failed to build keymap\n"); 352 return error; 353 } 354 355 if (rep) 356 __set_bit(EV_REP, input->evbit); 357 input_set_capability(input, EV_MSC, MSC_SCAN); 358 359 input_set_drvdata(input, keypad_data); 360 361 irq = client->irq; 362 if (irq_is_gpio) 363 irq = gpio_to_irq(irq); 364 365 error = devm_request_threaded_irq(dev, irq, NULL, tca8418_irq_handler, 366 IRQF_TRIGGER_FALLING | 367 IRQF_SHARED | 368 IRQF_ONESHOT, 369 client->name, keypad_data); 370 if (error) { 371 dev_err(dev, "Unable to claim irq %d; error %d\n", 372 client->irq, error); 373 return error; 374 } 375 376 error = input_register_device(input); 377 if (error) { 378 dev_err(dev, "Unable to register input device, error: %d\n", 379 error); 380 return error; 381 } 382 383 return 0; 384 } 385 386 static const struct i2c_device_id tca8418_id[] = { 387 { TCA8418_NAME, 8418, }, 388 { } 389 }; 390 MODULE_DEVICE_TABLE(i2c, tca8418_id); 391 392 #ifdef CONFIG_OF 393 static const struct of_device_id tca8418_dt_ids[] = { 394 { .compatible = "ti,tca8418", }, 395 { } 396 }; 397 MODULE_DEVICE_TABLE(of, tca8418_dt_ids); 398 399 /* 400 * The device tree based i2c loader looks for 401 * "i2c:" + second_component_of(property("compatible")) 402 * and therefore we need an alias to be found. 403 */ 404 MODULE_ALIAS("i2c:tca8418"); 405 #endif 406 407 static struct i2c_driver tca8418_keypad_driver = { 408 .driver = { 409 .name = TCA8418_NAME, 410 .of_match_table = of_match_ptr(tca8418_dt_ids), 411 }, 412 .probe = tca8418_keypad_probe, 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"); 431