Sriramakrishnan Govindarajan | 30ba3ea | 2010-05-03 23:47:12 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Driver for keys on TCA6416 I2C IO expander |
| 3 | * |
| 4 | * Copyright (C) 2010 Texas Instruments |
| 5 | * |
| 6 | * Author : Sriramakrishnan.A.G. <srk@ti.com> |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License version 2 as |
| 10 | * published by the Free Software Foundation. |
| 11 | */ |
| 12 | |
| 13 | #include <linux/types.h> |
| 14 | #include <linux/module.h> |
| 15 | #include <linux/init.h> |
| 16 | #include <linux/delay.h> |
| 17 | #include <linux/slab.h> |
| 18 | #include <linux/interrupt.h> |
| 19 | #include <linux/workqueue.h> |
| 20 | #include <linux/gpio.h> |
| 21 | #include <linux/i2c.h> |
| 22 | #include <linux/input.h> |
| 23 | #include <linux/tca6416_keypad.h> |
| 24 | |
| 25 | #define TCA6416_INPUT 0 |
| 26 | #define TCA6416_OUTPUT 1 |
| 27 | #define TCA6416_INVERT 2 |
| 28 | #define TCA6416_DIRECTION 3 |
| 29 | |
| 30 | static const struct i2c_device_id tca6416_id[] = { |
| 31 | { "tca6416-keys", 16, }, |
Tony SIM | b8a3d6b | 2010-12-07 02:54:00 -0800 | [diff] [blame] | 32 | { "tca6408-keys", 8, }, |
Sriramakrishnan Govindarajan | 30ba3ea | 2010-05-03 23:47:12 -0700 | [diff] [blame] | 33 | { } |
| 34 | }; |
| 35 | MODULE_DEVICE_TABLE(i2c, tca6416_id); |
| 36 | |
| 37 | struct tca6416_drv_data { |
| 38 | struct input_dev *input; |
| 39 | struct tca6416_button data[0]; |
| 40 | }; |
| 41 | |
| 42 | struct tca6416_keypad_chip { |
| 43 | uint16_t reg_output; |
| 44 | uint16_t reg_direction; |
| 45 | uint16_t reg_input; |
| 46 | |
| 47 | struct i2c_client *client; |
| 48 | struct input_dev *input; |
| 49 | struct delayed_work dwork; |
Tony SIM | b8a3d6b | 2010-12-07 02:54:00 -0800 | [diff] [blame] | 50 | int io_size; |
Sriramakrishnan Govindarajan | 30ba3ea | 2010-05-03 23:47:12 -0700 | [diff] [blame] | 51 | int irqnum; |
Tony SIM | b8a3d6b | 2010-12-07 02:54:00 -0800 | [diff] [blame] | 52 | u16 pinmask; |
Sriramakrishnan Govindarajan | 30ba3ea | 2010-05-03 23:47:12 -0700 | [diff] [blame] | 53 | bool use_polling; |
| 54 | struct tca6416_button buttons[0]; |
| 55 | }; |
| 56 | |
| 57 | static int tca6416_write_reg(struct tca6416_keypad_chip *chip, int reg, u16 val) |
| 58 | { |
| 59 | int error; |
| 60 | |
Tony SIM | b8a3d6b | 2010-12-07 02:54:00 -0800 | [diff] [blame] | 61 | error = chip->io_size > 8 ? |
| 62 | i2c_smbus_write_word_data(chip->client, reg << 1, val) : |
| 63 | i2c_smbus_write_byte_data(chip->client, reg, val); |
Sriramakrishnan Govindarajan | 30ba3ea | 2010-05-03 23:47:12 -0700 | [diff] [blame] | 64 | if (error < 0) { |
| 65 | dev_err(&chip->client->dev, |
| 66 | "%s failed, reg: %d, val: %d, error: %d\n", |
| 67 | __func__, reg, val, error); |
| 68 | return error; |
| 69 | } |
| 70 | |
| 71 | return 0; |
| 72 | } |
| 73 | |
| 74 | static int tca6416_read_reg(struct tca6416_keypad_chip *chip, int reg, u16 *val) |
| 75 | { |
| 76 | int retval; |
| 77 | |
Tony SIM | b8a3d6b | 2010-12-07 02:54:00 -0800 | [diff] [blame] | 78 | retval = chip->io_size > 8 ? |
| 79 | i2c_smbus_read_word_data(chip->client, reg << 1) : |
| 80 | i2c_smbus_read_byte_data(chip->client, reg); |
Sriramakrishnan Govindarajan | 30ba3ea | 2010-05-03 23:47:12 -0700 | [diff] [blame] | 81 | if (retval < 0) { |
| 82 | dev_err(&chip->client->dev, "%s failed, reg: %d, error: %d\n", |
| 83 | __func__, reg, retval); |
| 84 | return retval; |
| 85 | } |
| 86 | |
| 87 | *val = (u16)retval; |
| 88 | return 0; |
| 89 | } |
| 90 | |
| 91 | static void tca6416_keys_scan(struct tca6416_keypad_chip *chip) |
| 92 | { |
| 93 | struct input_dev *input = chip->input; |
| 94 | u16 reg_val, val; |
| 95 | int error, i, pin_index; |
| 96 | |
| 97 | error = tca6416_read_reg(chip, TCA6416_INPUT, ®_val); |
| 98 | if (error) |
| 99 | return; |
| 100 | |
| 101 | reg_val &= chip->pinmask; |
| 102 | |
| 103 | /* Figure out which lines have changed */ |
| 104 | val = reg_val ^ chip->reg_input; |
| 105 | chip->reg_input = reg_val; |
| 106 | |
| 107 | for (i = 0, pin_index = 0; i < 16; i++) { |
| 108 | if (val & (1 << i)) { |
| 109 | struct tca6416_button *button = &chip->buttons[pin_index]; |
| 110 | unsigned int type = button->type ?: EV_KEY; |
| 111 | int state = ((reg_val & (1 << i)) ? 1 : 0) |
| 112 | ^ button->active_low; |
| 113 | |
| 114 | input_event(input, type, button->code, !!state); |
| 115 | input_sync(input); |
| 116 | } |
| 117 | |
| 118 | if (chip->pinmask & (1 << i)) |
| 119 | pin_index++; |
| 120 | } |
| 121 | } |
| 122 | |
| 123 | /* |
| 124 | * This is threaded IRQ handler and this can (and will) sleep. |
| 125 | */ |
| 126 | static irqreturn_t tca6416_keys_isr(int irq, void *dev_id) |
| 127 | { |
| 128 | struct tca6416_keypad_chip *chip = dev_id; |
| 129 | |
| 130 | tca6416_keys_scan(chip); |
| 131 | |
| 132 | return IRQ_HANDLED; |
| 133 | } |
| 134 | |
| 135 | static void tca6416_keys_work_func(struct work_struct *work) |
| 136 | { |
| 137 | struct tca6416_keypad_chip *chip = |
| 138 | container_of(work, struct tca6416_keypad_chip, dwork.work); |
| 139 | |
| 140 | tca6416_keys_scan(chip); |
| 141 | schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100)); |
| 142 | } |
| 143 | |
| 144 | static int tca6416_keys_open(struct input_dev *dev) |
| 145 | { |
| 146 | struct tca6416_keypad_chip *chip = input_get_drvdata(dev); |
| 147 | |
| 148 | /* Get initial device state in case it has switches */ |
| 149 | tca6416_keys_scan(chip); |
| 150 | |
| 151 | if (chip->use_polling) |
| 152 | schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100)); |
| 153 | else |
| 154 | enable_irq(chip->irqnum); |
| 155 | |
| 156 | return 0; |
| 157 | } |
| 158 | |
| 159 | static void tca6416_keys_close(struct input_dev *dev) |
| 160 | { |
| 161 | struct tca6416_keypad_chip *chip = input_get_drvdata(dev); |
| 162 | |
| 163 | if (chip->use_polling) |
| 164 | cancel_delayed_work_sync(&chip->dwork); |
| 165 | else |
| 166 | disable_irq(chip->irqnum); |
| 167 | } |
| 168 | |
| 169 | static int __devinit tca6416_setup_registers(struct tca6416_keypad_chip *chip) |
| 170 | { |
| 171 | int error; |
| 172 | |
| 173 | error = tca6416_read_reg(chip, TCA6416_OUTPUT, &chip->reg_output); |
| 174 | if (error) |
| 175 | return error; |
| 176 | |
| 177 | error = tca6416_read_reg(chip, TCA6416_DIRECTION, &chip->reg_direction); |
| 178 | if (error) |
| 179 | return error; |
| 180 | |
| 181 | /* ensure that keypad pins are set to input */ |
| 182 | error = tca6416_write_reg(chip, TCA6416_DIRECTION, |
| 183 | chip->reg_direction | chip->pinmask); |
| 184 | if (error) |
| 185 | return error; |
| 186 | |
| 187 | error = tca6416_read_reg(chip, TCA6416_DIRECTION, &chip->reg_direction); |
| 188 | if (error) |
| 189 | return error; |
| 190 | |
| 191 | error = tca6416_read_reg(chip, TCA6416_INPUT, &chip->reg_input); |
| 192 | if (error) |
| 193 | return error; |
| 194 | |
| 195 | chip->reg_input &= chip->pinmask; |
| 196 | |
| 197 | return 0; |
| 198 | } |
| 199 | |
| 200 | static int __devinit tca6416_keypad_probe(struct i2c_client *client, |
| 201 | const struct i2c_device_id *id) |
| 202 | { |
| 203 | struct tca6416_keys_platform_data *pdata; |
| 204 | struct tca6416_keypad_chip *chip; |
| 205 | struct input_dev *input; |
| 206 | int error; |
| 207 | int i; |
| 208 | |
| 209 | /* Check functionality */ |
| 210 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE)) { |
| 211 | dev_err(&client->dev, "%s adapter not supported\n", |
| 212 | dev_driver_string(&client->adapter->dev)); |
| 213 | return -ENODEV; |
| 214 | } |
| 215 | |
| 216 | pdata = client->dev.platform_data; |
| 217 | if (!pdata) { |
| 218 | dev_dbg(&client->dev, "no platform data\n"); |
| 219 | return -EINVAL; |
| 220 | } |
| 221 | |
| 222 | chip = kzalloc(sizeof(struct tca6416_keypad_chip) + |
| 223 | pdata->nbuttons * sizeof(struct tca6416_button), |
| 224 | GFP_KERNEL); |
| 225 | input = input_allocate_device(); |
| 226 | if (!chip || !input) { |
| 227 | error = -ENOMEM; |
| 228 | goto fail1; |
| 229 | } |
| 230 | |
| 231 | chip->client = client; |
| 232 | chip->input = input; |
Tony SIM | b8a3d6b | 2010-12-07 02:54:00 -0800 | [diff] [blame] | 233 | chip->io_size = id->driver_data; |
Sriramakrishnan Govindarajan | 30ba3ea | 2010-05-03 23:47:12 -0700 | [diff] [blame] | 234 | chip->pinmask = pdata->pinmask; |
| 235 | chip->use_polling = pdata->use_polling; |
| 236 | |
| 237 | INIT_DELAYED_WORK(&chip->dwork, tca6416_keys_work_func); |
| 238 | |
| 239 | input->phys = "tca6416-keys/input0"; |
| 240 | input->name = client->name; |
| 241 | input->dev.parent = &client->dev; |
| 242 | |
| 243 | input->open = tca6416_keys_open; |
| 244 | input->close = tca6416_keys_close; |
| 245 | |
| 246 | input->id.bustype = BUS_HOST; |
| 247 | input->id.vendor = 0x0001; |
| 248 | input->id.product = 0x0001; |
| 249 | input->id.version = 0x0100; |
| 250 | |
| 251 | /* Enable auto repeat feature of Linux input subsystem */ |
| 252 | if (pdata->rep) |
| 253 | __set_bit(EV_REP, input->evbit); |
| 254 | |
| 255 | for (i = 0; i < pdata->nbuttons; i++) { |
| 256 | unsigned int type; |
| 257 | |
| 258 | chip->buttons[i] = pdata->buttons[i]; |
| 259 | type = (pdata->buttons[i].type) ?: EV_KEY; |
| 260 | input_set_capability(input, type, pdata->buttons[i].code); |
| 261 | } |
| 262 | |
| 263 | input_set_drvdata(input, chip); |
| 264 | |
| 265 | /* |
| 266 | * Initialize cached registers from their original values. |
| 267 | * we can't share this chip with another i2c master. |
| 268 | */ |
| 269 | error = tca6416_setup_registers(chip); |
| 270 | if (error) |
| 271 | goto fail1; |
| 272 | |
| 273 | if (!chip->use_polling) { |
| 274 | if (pdata->irq_is_gpio) |
| 275 | chip->irqnum = gpio_to_irq(client->irq); |
| 276 | else |
| 277 | chip->irqnum = client->irq; |
| 278 | |
| 279 | error = request_threaded_irq(chip->irqnum, NULL, |
| 280 | tca6416_keys_isr, |
Lars-Peter Clausen | 9b7e31b | 2012-07-04 13:02:56 -0700 | [diff] [blame] | 281 | IRQF_TRIGGER_FALLING | |
| 282 | IRQF_ONESHOT, |
Sriramakrishnan Govindarajan | 30ba3ea | 2010-05-03 23:47:12 -0700 | [diff] [blame] | 283 | "tca6416-keypad", chip); |
| 284 | if (error) { |
| 285 | dev_dbg(&client->dev, |
| 286 | "Unable to claim irq %d; error %d\n", |
| 287 | chip->irqnum, error); |
| 288 | goto fail1; |
| 289 | } |
| 290 | disable_irq(chip->irqnum); |
| 291 | } |
| 292 | |
| 293 | error = input_register_device(input); |
| 294 | if (error) { |
| 295 | dev_dbg(&client->dev, |
| 296 | "Unable to register input device, error: %d\n", error); |
| 297 | goto fail2; |
| 298 | } |
| 299 | |
| 300 | i2c_set_clientdata(client, chip); |
Magnus Damm | 64dcddd | 2011-03-15 22:32:39 -0700 | [diff] [blame] | 301 | device_init_wakeup(&client->dev, 1); |
Sriramakrishnan Govindarajan | 30ba3ea | 2010-05-03 23:47:12 -0700 | [diff] [blame] | 302 | |
| 303 | return 0; |
| 304 | |
| 305 | fail2: |
| 306 | if (!chip->use_polling) { |
| 307 | free_irq(chip->irqnum, chip); |
| 308 | enable_irq(chip->irqnum); |
| 309 | } |
| 310 | fail1: |
| 311 | input_free_device(input); |
| 312 | kfree(chip); |
| 313 | return error; |
| 314 | } |
| 315 | |
| 316 | static int __devexit tca6416_keypad_remove(struct i2c_client *client) |
| 317 | { |
| 318 | struct tca6416_keypad_chip *chip = i2c_get_clientdata(client); |
| 319 | |
| 320 | if (!chip->use_polling) { |
| 321 | free_irq(chip->irqnum, chip); |
| 322 | enable_irq(chip->irqnum); |
| 323 | } |
| 324 | |
| 325 | input_unregister_device(chip->input); |
| 326 | kfree(chip); |
| 327 | |
Sriramakrishnan Govindarajan | 30ba3ea | 2010-05-03 23:47:12 -0700 | [diff] [blame] | 328 | return 0; |
| 329 | } |
| 330 | |
Magnus Damm | 64dcddd | 2011-03-15 22:32:39 -0700 | [diff] [blame] | 331 | #ifdef CONFIG_PM_SLEEP |
| 332 | static int tca6416_keypad_suspend(struct device *dev) |
| 333 | { |
| 334 | struct i2c_client *client = to_i2c_client(dev); |
| 335 | struct tca6416_keypad_chip *chip = i2c_get_clientdata(client); |
| 336 | |
| 337 | if (device_may_wakeup(dev)) |
| 338 | enable_irq_wake(chip->irqnum); |
| 339 | |
| 340 | return 0; |
| 341 | } |
| 342 | |
| 343 | static int tca6416_keypad_resume(struct device *dev) |
| 344 | { |
| 345 | struct i2c_client *client = to_i2c_client(dev); |
| 346 | struct tca6416_keypad_chip *chip = i2c_get_clientdata(client); |
| 347 | |
| 348 | if (device_may_wakeup(dev)) |
| 349 | disable_irq_wake(chip->irqnum); |
| 350 | |
| 351 | return 0; |
| 352 | } |
| 353 | #endif |
| 354 | |
| 355 | static SIMPLE_DEV_PM_OPS(tca6416_keypad_dev_pm_ops, |
| 356 | tca6416_keypad_suspend, tca6416_keypad_resume); |
Sriramakrishnan Govindarajan | 30ba3ea | 2010-05-03 23:47:12 -0700 | [diff] [blame] | 357 | |
| 358 | static struct i2c_driver tca6416_keypad_driver = { |
| 359 | .driver = { |
| 360 | .name = "tca6416-keypad", |
Magnus Damm | 64dcddd | 2011-03-15 22:32:39 -0700 | [diff] [blame] | 361 | .pm = &tca6416_keypad_dev_pm_ops, |
Sriramakrishnan Govindarajan | 30ba3ea | 2010-05-03 23:47:12 -0700 | [diff] [blame] | 362 | }, |
| 363 | .probe = tca6416_keypad_probe, |
Bill Pemberton | 1cb0aa8 | 2012-11-23 21:27:39 -0800 | [diff] [blame^] | 364 | .remove = tca6416_keypad_remove, |
Sriramakrishnan Govindarajan | 30ba3ea | 2010-05-03 23:47:12 -0700 | [diff] [blame] | 365 | .id_table = tca6416_id, |
| 366 | }; |
| 367 | |
| 368 | static int __init tca6416_keypad_init(void) |
| 369 | { |
| 370 | return i2c_add_driver(&tca6416_keypad_driver); |
| 371 | } |
| 372 | |
| 373 | subsys_initcall(tca6416_keypad_init); |
| 374 | |
| 375 | static void __exit tca6416_keypad_exit(void) |
| 376 | { |
| 377 | i2c_del_driver(&tca6416_keypad_driver); |
| 378 | } |
| 379 | module_exit(tca6416_keypad_exit); |
| 380 | |
| 381 | MODULE_AUTHOR("Sriramakrishnan <srk@ti.com>"); |
| 382 | MODULE_DESCRIPTION("Keypad driver over tca6146 IO expander"); |
| 383 | MODULE_LICENSE("GPL"); |