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, ®); 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, ®); 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; 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); 294 295 /* Allocate memory for keypad_data and input device */ 296 keypad_data = devm_kzalloc(dev, sizeof(*keypad_data), GFP_KERNEL); 297 if (!keypad_data) 298 return -ENOMEM; 299 300 keypad_data->client = client; 301 keypad_data->row_shift = row_shift; 302 303 /* Read key lock register, if this fails assume device not present */ 304 error = tca8418_read_byte(keypad_data, REG_KEY_LCK_EC, ®); 305 if (error) 306 return -ENODEV; 307 308 /* Configure input device */ 309 input = devm_input_allocate_device(dev); 310 if (!input) 311 return -ENOMEM; 312 313 keypad_data->input = input; 314 315 input->name = client->name; 316 input->id.bustype = BUS_I2C; 317 input->id.vendor = 0x0001; 318 input->id.product = 0x001; 319 input->id.version = 0x0001; 320 321 error = matrix_keypad_build_keymap(NULL, NULL, rows, cols, NULL, input); 322 if (error) { 323 dev_err(dev, "Failed to build keymap\n"); 324 return error; 325 } 326 327 if (device_property_read_bool(dev, "keypad,autorepeat")) 328 __set_bit(EV_REP, input->evbit); 329 330 input_set_capability(input, EV_MSC, MSC_SCAN); 331 332 error = devm_request_threaded_irq(dev, client->irq, 333 NULL, tca8418_irq_handler, 334 IRQF_SHARED | IRQF_ONESHOT, 335 client->name, keypad_data); 336 if (error) { 337 dev_err(dev, "Unable to claim irq %d; error %d\n", 338 client->irq, error); 339 return error; 340 } 341 342 /* Initialize the chip */ 343 error = tca8418_configure(keypad_data, rows, cols); 344 if (error < 0) 345 return error; 346 347 error = input_register_device(input); 348 if (error) { 349 dev_err(dev, "Unable to register input device, error: %d\n", 350 error); 351 return error; 352 } 353 354 return 0; 355 } 356 357 static const struct i2c_device_id tca8418_id[] = { 358 { "tca8418", 8418, }, 359 { } 360 }; 361 MODULE_DEVICE_TABLE(i2c, tca8418_id); 362 363 static const struct of_device_id tca8418_dt_ids[] = { 364 { .compatible = "ti,tca8418", }, 365 { } 366 }; 367 MODULE_DEVICE_TABLE(of, tca8418_dt_ids); 368 369 static struct i2c_driver tca8418_keypad_driver = { 370 .driver = { 371 .name = "tca8418_keypad", 372 .of_match_table = tca8418_dt_ids, 373 }, 374 .probe = tca8418_keypad_probe, 375 .id_table = tca8418_id, 376 }; 377 378 static int __init tca8418_keypad_init(void) 379 { 380 return i2c_add_driver(&tca8418_keypad_driver); 381 } 382 subsys_initcall(tca8418_keypad_init); 383 384 static void __exit tca8418_keypad_exit(void) 385 { 386 i2c_del_driver(&tca8418_keypad_driver); 387 } 388 module_exit(tca8418_keypad_exit); 389 390 MODULE_AUTHOR("Kyle Manna <kyle.manna@fuel7.com>"); 391 MODULE_DESCRIPTION("Keypad driver for TCA8418"); 392 MODULE_LICENSE("GPL"); 393