1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Driver for keys on TCA6416 I2C IO expander 4 * 5 * Copyright (C) 2010 Texas Instruments 6 * 7 * Author : Sriramakrishnan.A.G. <srk@ti.com> 8 */ 9 10 #include <linux/types.h> 11 #include <linux/module.h> 12 #include <linux/init.h> 13 #include <linux/delay.h> 14 #include <linux/slab.h> 15 #include <linux/interrupt.h> 16 #include <linux/workqueue.h> 17 #include <linux/gpio.h> 18 #include <linux/i2c.h> 19 #include <linux/input.h> 20 #include <linux/tca6416_keypad.h> 21 22 #define TCA6416_INPUT 0 23 #define TCA6416_OUTPUT 1 24 #define TCA6416_INVERT 2 25 #define TCA6416_DIRECTION 3 26 27 static const struct i2c_device_id tca6416_id[] = { 28 { "tca6416-keys", 16, }, 29 { "tca6408-keys", 8, }, 30 { } 31 }; 32 MODULE_DEVICE_TABLE(i2c, tca6416_id); 33 34 struct tca6416_drv_data { 35 struct input_dev *input; 36 struct tca6416_button data[]; 37 }; 38 39 struct tca6416_keypad_chip { 40 uint16_t reg_output; 41 uint16_t reg_direction; 42 uint16_t reg_input; 43 44 struct i2c_client *client; 45 struct input_dev *input; 46 struct delayed_work dwork; 47 int io_size; 48 int irqnum; 49 u16 pinmask; 50 bool use_polling; 51 struct tca6416_button buttons[]; 52 }; 53 54 static int tca6416_write_reg(struct tca6416_keypad_chip *chip, int reg, u16 val) 55 { 56 int error; 57 58 error = chip->io_size > 8 ? 59 i2c_smbus_write_word_data(chip->client, reg << 1, val) : 60 i2c_smbus_write_byte_data(chip->client, reg, val); 61 if (error < 0) { 62 dev_err(&chip->client->dev, 63 "%s failed, reg: %d, val: %d, error: %d\n", 64 __func__, reg, val, error); 65 return error; 66 } 67 68 return 0; 69 } 70 71 static int tca6416_read_reg(struct tca6416_keypad_chip *chip, int reg, u16 *val) 72 { 73 int retval; 74 75 retval = chip->io_size > 8 ? 76 i2c_smbus_read_word_data(chip->client, reg << 1) : 77 i2c_smbus_read_byte_data(chip->client, reg); 78 if (retval < 0) { 79 dev_err(&chip->client->dev, "%s failed, reg: %d, error: %d\n", 80 __func__, reg, retval); 81 return retval; 82 } 83 84 *val = (u16)retval; 85 return 0; 86 } 87 88 static void tca6416_keys_scan(struct tca6416_keypad_chip *chip) 89 { 90 struct input_dev *input = chip->input; 91 u16 reg_val, val; 92 int error, i, pin_index; 93 94 error = tca6416_read_reg(chip, TCA6416_INPUT, ®_val); 95 if (error) 96 return; 97 98 reg_val &= chip->pinmask; 99 100 /* Figure out which lines have changed */ 101 val = reg_val ^ chip->reg_input; 102 chip->reg_input = reg_val; 103 104 for (i = 0, pin_index = 0; i < 16; i++) { 105 if (val & (1 << i)) { 106 struct tca6416_button *button = &chip->buttons[pin_index]; 107 unsigned int type = button->type ?: EV_KEY; 108 int state = ((reg_val & (1 << i)) ? 1 : 0) 109 ^ button->active_low; 110 111 input_event(input, type, button->code, !!state); 112 input_sync(input); 113 } 114 115 if (chip->pinmask & (1 << i)) 116 pin_index++; 117 } 118 } 119 120 /* 121 * This is threaded IRQ handler and this can (and will) sleep. 122 */ 123 static irqreturn_t tca6416_keys_isr(int irq, void *dev_id) 124 { 125 struct tca6416_keypad_chip *chip = dev_id; 126 127 tca6416_keys_scan(chip); 128 129 return IRQ_HANDLED; 130 } 131 132 static void tca6416_keys_work_func(struct work_struct *work) 133 { 134 struct tca6416_keypad_chip *chip = 135 container_of(work, struct tca6416_keypad_chip, dwork.work); 136 137 tca6416_keys_scan(chip); 138 schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100)); 139 } 140 141 static int tca6416_keys_open(struct input_dev *dev) 142 { 143 struct tca6416_keypad_chip *chip = input_get_drvdata(dev); 144 145 /* Get initial device state in case it has switches */ 146 tca6416_keys_scan(chip); 147 148 if (chip->use_polling) 149 schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100)); 150 else 151 enable_irq(chip->irqnum); 152 153 return 0; 154 } 155 156 static void tca6416_keys_close(struct input_dev *dev) 157 { 158 struct tca6416_keypad_chip *chip = input_get_drvdata(dev); 159 160 if (chip->use_polling) 161 cancel_delayed_work_sync(&chip->dwork); 162 else 163 disable_irq(chip->irqnum); 164 } 165 166 static int tca6416_setup_registers(struct tca6416_keypad_chip *chip) 167 { 168 int error; 169 170 error = tca6416_read_reg(chip, TCA6416_OUTPUT, &chip->reg_output); 171 if (error) 172 return error; 173 174 error = tca6416_read_reg(chip, TCA6416_DIRECTION, &chip->reg_direction); 175 if (error) 176 return error; 177 178 /* ensure that keypad pins are set to input */ 179 error = tca6416_write_reg(chip, TCA6416_DIRECTION, 180 chip->reg_direction | chip->pinmask); 181 if (error) 182 return error; 183 184 error = tca6416_read_reg(chip, TCA6416_DIRECTION, &chip->reg_direction); 185 if (error) 186 return error; 187 188 error = tca6416_read_reg(chip, TCA6416_INPUT, &chip->reg_input); 189 if (error) 190 return error; 191 192 chip->reg_input &= chip->pinmask; 193 194 return 0; 195 } 196 197 static int tca6416_keypad_probe(struct i2c_client *client, 198 const struct i2c_device_id *id) 199 { 200 struct tca6416_keys_platform_data *pdata; 201 struct tca6416_keypad_chip *chip; 202 struct input_dev *input; 203 int error; 204 int i; 205 206 /* Check functionality */ 207 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE)) { 208 dev_err(&client->dev, "%s adapter not supported\n", 209 dev_driver_string(&client->adapter->dev)); 210 return -ENODEV; 211 } 212 213 pdata = dev_get_platdata(&client->dev); 214 if (!pdata) { 215 dev_dbg(&client->dev, "no platform data\n"); 216 return -EINVAL; 217 } 218 219 chip = kzalloc(struct_size(chip, buttons, pdata->nbuttons), GFP_KERNEL); 220 input = input_allocate_device(); 221 if (!chip || !input) { 222 error = -ENOMEM; 223 goto fail1; 224 } 225 226 chip->client = client; 227 chip->input = input; 228 chip->io_size = id->driver_data; 229 chip->pinmask = pdata->pinmask; 230 chip->use_polling = pdata->use_polling; 231 232 INIT_DELAYED_WORK(&chip->dwork, tca6416_keys_work_func); 233 234 input->phys = "tca6416-keys/input0"; 235 input->name = client->name; 236 input->dev.parent = &client->dev; 237 238 input->open = tca6416_keys_open; 239 input->close = tca6416_keys_close; 240 241 input->id.bustype = BUS_HOST; 242 input->id.vendor = 0x0001; 243 input->id.product = 0x0001; 244 input->id.version = 0x0100; 245 246 /* Enable auto repeat feature of Linux input subsystem */ 247 if (pdata->rep) 248 __set_bit(EV_REP, input->evbit); 249 250 for (i = 0; i < pdata->nbuttons; i++) { 251 unsigned int type; 252 253 chip->buttons[i] = pdata->buttons[i]; 254 type = (pdata->buttons[i].type) ?: EV_KEY; 255 input_set_capability(input, type, pdata->buttons[i].code); 256 } 257 258 input_set_drvdata(input, chip); 259 260 /* 261 * Initialize cached registers from their original values. 262 * we can't share this chip with another i2c master. 263 */ 264 error = tca6416_setup_registers(chip); 265 if (error) 266 goto fail1; 267 268 if (!chip->use_polling) { 269 if (pdata->irq_is_gpio) 270 chip->irqnum = gpio_to_irq(client->irq); 271 else 272 chip->irqnum = client->irq; 273 274 error = request_threaded_irq(chip->irqnum, NULL, 275 tca6416_keys_isr, 276 IRQF_TRIGGER_FALLING | 277 IRQF_ONESHOT, 278 "tca6416-keypad", chip); 279 if (error) { 280 dev_dbg(&client->dev, 281 "Unable to claim irq %d; error %d\n", 282 chip->irqnum, error); 283 goto fail1; 284 } 285 disable_irq(chip->irqnum); 286 } 287 288 error = input_register_device(input); 289 if (error) { 290 dev_dbg(&client->dev, 291 "Unable to register input device, error: %d\n", error); 292 goto fail2; 293 } 294 295 i2c_set_clientdata(client, chip); 296 device_init_wakeup(&client->dev, 1); 297 298 return 0; 299 300 fail2: 301 if (!chip->use_polling) { 302 free_irq(chip->irqnum, chip); 303 enable_irq(chip->irqnum); 304 } 305 fail1: 306 input_free_device(input); 307 kfree(chip); 308 return error; 309 } 310 311 static int tca6416_keypad_remove(struct i2c_client *client) 312 { 313 struct tca6416_keypad_chip *chip = i2c_get_clientdata(client); 314 315 if (!chip->use_polling) { 316 free_irq(chip->irqnum, chip); 317 enable_irq(chip->irqnum); 318 } 319 320 input_unregister_device(chip->input); 321 kfree(chip); 322 323 return 0; 324 } 325 326 #ifdef CONFIG_PM_SLEEP 327 static int tca6416_keypad_suspend(struct device *dev) 328 { 329 struct i2c_client *client = to_i2c_client(dev); 330 struct tca6416_keypad_chip *chip = i2c_get_clientdata(client); 331 332 if (device_may_wakeup(dev)) 333 enable_irq_wake(chip->irqnum); 334 335 return 0; 336 } 337 338 static int tca6416_keypad_resume(struct device *dev) 339 { 340 struct i2c_client *client = to_i2c_client(dev); 341 struct tca6416_keypad_chip *chip = i2c_get_clientdata(client); 342 343 if (device_may_wakeup(dev)) 344 disable_irq_wake(chip->irqnum); 345 346 return 0; 347 } 348 #endif 349 350 static SIMPLE_DEV_PM_OPS(tca6416_keypad_dev_pm_ops, 351 tca6416_keypad_suspend, tca6416_keypad_resume); 352 353 static struct i2c_driver tca6416_keypad_driver = { 354 .driver = { 355 .name = "tca6416-keypad", 356 .pm = &tca6416_keypad_dev_pm_ops, 357 }, 358 .probe = tca6416_keypad_probe, 359 .remove = tca6416_keypad_remove, 360 .id_table = tca6416_id, 361 }; 362 363 static int __init tca6416_keypad_init(void) 364 { 365 return i2c_add_driver(&tca6416_keypad_driver); 366 } 367 368 subsys_initcall(tca6416_keypad_init); 369 370 static void __exit tca6416_keypad_exit(void) 371 { 372 i2c_del_driver(&tca6416_keypad_driver); 373 } 374 module_exit(tca6416_keypad_exit); 375 376 MODULE_AUTHOR("Sriramakrishnan <srk@ti.com>"); 377 MODULE_DESCRIPTION("Keypad driver over tca6416 IO expander"); 378 MODULE_LICENSE("GPL"); 379