drivers/input/keyboard/tca6416-keypad.c

   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. <[email protected]>
   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, &reg_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 <[email protected]>");
 377 MODULE_DESCRIPTION("Keypad driver over tca6416 IO expander");
 378 MODULE_LICENSE("GPL");