drivers/input/keyboard/rk_keys.c

   1 /*
   2  * Driver for keys on GPIO lines capable of generating interrupts.
   3  *
   4  * Copyright (C) 2015, Fuzhou Rockchip Electronics Co., Ltd
   5  * Copyright 2005 Phil Blundell
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/fs.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/irq.h>
  17 #include <linux/sched.h>
  18 #include <linux/pm.h>
  19 #include <linux/sysctl.h>
  20 #include <linux/proc_fs.h>
  21 #include <linux/delay.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/input.h>
  24 #include <linux/adc.h>
  25 #include <linux/slab.h>
  26 #include <linux/wakelock.h>
  27
  28 #include <linux/iio/iio.h>
  29 #include <linux/iio/machine.h>
  30 #include <linux/iio/driver.h>
  31 #include <linux/iio/consumer.h>
  32
  33 #include <linux/gpio.h>
  34 #include <linux/of.h>
  35 #include <linux/of_irq.h>
  36 #include <linux/of_gpio.h>
  37 #include <linux/of_platform.h>
  38
  39 #define EMPTY_ADVALUE                   950
  40 #define DRIFT_ADVALUE                   70
  41 #define INVALID_ADVALUE                 -1
  42 #define EV_ENCALL                       KEY_F4
  43 #define EV_MENU                         KEY_F1
  44
  45 #if 0
  46 #define key_dbg(bdata, format, arg...)          \
  47         dev_info(&bdata->input->dev, format, ##arg)
  48 #else
  49 #define key_dbg(bdata, format, arg...)
  50 #endif
  51
  52 #define DEBOUNCE_JIFFIES        (10 / (MSEC_PER_SEC / HZ))      /* 10ms */
  53 #define ADC_SAMPLE_JIFFIES      (100 / (MSEC_PER_SEC / HZ))     /* 100ms */
  54 #define WAKE_LOCK_JIFFIES       (1 * HZ)                        /* 1s */
  55
  56 enum rk_key_type {
  57         TYPE_GPIO = 1,
  58         TYPE_ADC
  59 };
  60
  61 struct rk_keys_button {
  62         u32 type;               /* TYPE_GPIO, TYPE_ADC */
  63         u32 code;               /* key code */
  64         const char *desc;       /* key label */
  65         u32 state;              /* key up & down state */
  66         int gpio;               /* gpio only */
  67         int adc_value;          /* adc only */
  68         int adc_state;          /* adc only */
  69         int active_low;         /* gpio only */
  70         int wakeup;             /* gpio only */
  71         struct timer_list timer;
  72 };
  73
  74 struct rk_keys_drvdata {
  75         int nbuttons;
  76         /* flag to indicate if we're suspending/resuming */
  77         bool in_suspend;
  78         int result;
  79         int rep;
  80         struct wake_lock wake_lock;
  81         struct input_dev *input;
  82         struct delayed_work adc_poll_work;
  83         struct iio_channel *chan;
  84         struct rk_keys_button button[0];
  85 };
  86
  87 static struct input_dev *sinput_dev;
  88 static struct rk_keys_drvdata *spdata;
  89
  90 static void *rk_key_get_drvdata(void)
  91 {
  92         BUG_ON(!spdata);
  93         return spdata;
  94 }
  95
  96 void rk_send_power_key(int state)
  97 {
  98         if (!sinput_dev)
  99                 return;
 100         if (state) {
 101                 input_report_key(sinput_dev, KEY_POWER, 1);
 102                 input_sync(sinput_dev);
 103         } else {
 104                 input_report_key(sinput_dev, KEY_POWER, 0);
 105                 input_sync(sinput_dev);
 106         }
 107 }
 108 EXPORT_SYMBOL(rk_send_power_key);
 109
 110 void rk_send_wakeup_key(void)
 111 {
 112         if (!sinput_dev)
 113                 return;
 114
 115         input_report_key(sinput_dev, KEY_WAKEUP, 1);
 116         input_sync(sinput_dev);
 117         input_report_key(sinput_dev, KEY_WAKEUP, 0);
 118         input_sync(sinput_dev);
 119 }
 120 EXPORT_SYMBOL(rk_send_wakeup_key);
 121
 122 static void keys_timer(unsigned long _data)
 123 {
 124         struct rk_keys_drvdata *pdata = rk_key_get_drvdata();
 125         struct rk_keys_button *button = (struct rk_keys_button *)_data;
 126         struct input_dev *input = pdata->input;
 127         int state;
 128
 129         if (button->type == TYPE_GPIO)
 130                 state = !!((gpio_get_value(button->gpio) ? 1 : 0) ^
 131                            button->active_low);
 132         else
 133                 state = !!button->adc_state;
 134
 135         if (button->state != state) {
 136                 button->state = state;
 137                 input_event(input, EV_KEY, button->code, button->state);
 138                 key_dbg(pdata, "%skey[%s]: report event[%d] state[%d]\n",
 139                         button->type == TYPE_ADC ? "adc" : "gpio",
 140                         button->desc, button->code, button->state);
 141                 input_event(input, EV_KEY, button->code, button->state);
 142                 input_sync(input);
 143         }
 144
 145         if (state)
 146                 mod_timer(&button->timer, jiffies + DEBOUNCE_JIFFIES);
 147 }
 148
 149 static irqreturn_t keys_isr(int irq, void *dev_id)
 150 {
 151         struct rk_keys_drvdata *pdata = rk_key_get_drvdata();
 152         struct rk_keys_button *button = (struct rk_keys_button *)dev_id;
 153         struct input_dev *input = pdata->input;
 154
 155         BUG_ON(irq != gpio_to_irq(button->gpio));
 156
 157         if (button->wakeup && pdata->in_suspend) {
 158                 button->state = 1;
 159                 key_dbg(pdata,
 160                         "wakeup: %skey[%s]: report event[%d] state[%d]\n",
 161                         (button->type == TYPE_ADC) ? "adc" : "gpio",
 162                         button->desc, button->code, button->state);
 163                 input_event(input, EV_KEY, button->code, button->state);
 164                 input_sync(input);
 165         }
 166         if (button->wakeup)
 167                 wake_lock_timeout(&pdata->wake_lock, WAKE_LOCK_JIFFIES);
 168         mod_timer(&button->timer, jiffies + DEBOUNCE_JIFFIES);
 169
 170         return IRQ_HANDLED;
 171 }
 172
 173 /*
 174 static ssize_t adc_value_show(struct device *dev, struct device_attribute *attr,
 175                               char *buf)
 176 {
 177         struct rk_keys_drvdata *ddata = dev_get_drvdata(dev);
 178
 179         return sprintf(buf, "adc_value: %d\n", ddata->result);
 180 }
 181 static DEVICE_ATTR(get_adc_value, S_IRUGO | S_IWUSR, adc_value_show, NULL);
 182 */
 183
 184 static const struct of_device_id rk_key_match[] = {
 185         { .compatible = "rockchip,key", .data = NULL},
 186         {},
 187 };
 188 MODULE_DEVICE_TABLE(of, rk_key_match);
 189
 190 static int rk_key_adc_iio_read(struct rk_keys_drvdata *data)
 191 {
 192         struct iio_channel *channel = data->chan;
 193         int val, ret;
 194
 195         if (!channel)
 196                 return INVALID_ADVALUE;
 197         ret = iio_read_channel_raw(channel, &val);
 198         if (ret < 0) {
 199                 pr_err("read channel() error: %d\n", ret);
 200                 return ret;
 201         }
 202         return val;
 203 }
 204
 205 static void adc_key_poll(struct work_struct *work)
 206 {
 207         struct rk_keys_drvdata *ddata;
 208         int i, result = -1;
 209
 210         ddata = container_of(work, struct rk_keys_drvdata, adc_poll_work.work);
 211         if (!ddata->in_suspend) {
 212                 result = rk_key_adc_iio_read(ddata);
 213                 if (result > INVALID_ADVALUE && result < EMPTY_ADVALUE)
 214                         ddata->result = result;
 215                 for (i = 0; i < ddata->nbuttons; i++) {
 216                         struct rk_keys_button *button = &ddata->button[i];
 217
 218                         if (!button->adc_value)
 219                                 continue;
 220                         if (result < button->adc_value + DRIFT_ADVALUE &&
 221                             result > button->adc_value - DRIFT_ADVALUE)
 222                                 button->adc_state = 1;
 223                         else
 224                                 button->adc_state = 0;
 225                         if (button->state != button->adc_state)
 226                                 mod_timer(&button->timer,
 227                                           jiffies + DEBOUNCE_JIFFIES);
 228                 }
 229         }
 230
 231         schedule_delayed_work(&ddata->adc_poll_work, ADC_SAMPLE_JIFFIES);
 232 }
 233
 234 static int rk_key_type_get(struct device_node *node,
 235                            struct rk_keys_button *button)
 236 {
 237         u32 adc_value;
 238
 239         if (!of_property_read_u32(node, "rockchip,adc_value", &adc_value))
 240                 return TYPE_ADC;
 241         else if (of_get_gpio(node, 0) >= 0)
 242                 return TYPE_GPIO;
 243         else
 244                 return -1;
 245 }
 246
 247 static int rk_keys_parse_dt(struct rk_keys_drvdata *pdata,
 248                             struct platform_device *pdev)
 249 {
 250         struct device_node *node = pdev->dev.of_node;
 251         struct device_node *child_node;
 252         struct iio_channel *chan;
 253         int ret, gpio, i = 0;
 254         u32 code, adc_value, flags;
 255
 256         chan = iio_channel_get(&pdev->dev, NULL);
 257         if (IS_ERR(chan)) {
 258                 dev_info(&pdev->dev, "no io-channels defined\n");
 259                 chan = NULL;
 260         }
 261         pdata->chan = chan;
 262
 263         for_each_child_of_node(node, child_node) {
 264                 if (of_property_read_u32(child_node, "linux,code", &code)) {
 265                         dev_err(&pdev->dev,
 266                                 "Missing linux,code property in the DT.\n");
 267                         ret = -EINVAL;
 268                         goto error_ret;
 269                 }
 270                 pdata->button[i].code = code;
 271                 pdata->button[i].desc =
 272                     of_get_property(child_node, "label", NULL);
 273                 pdata->button[i].type =
 274                     rk_key_type_get(child_node, &pdata->button[i]);
 275                 switch (pdata->button[i].type) {
 276                 case TYPE_GPIO:
 277                         gpio = of_get_gpio_flags(child_node, 0, &flags);
 278                         if (gpio < 0) {
 279                                 ret = gpio;
 280                                 if (ret != -EPROBE_DEFER)
 281                                         dev_err(&pdev->dev,
 282                                                 "Failed to get gpio flags, error: %d\n",
 283                                                 ret);
 284                                 goto error_ret;
 285                         }
 286
 287                         pdata->button[i].gpio = gpio;
 288                         pdata->button[i].active_low =
 289                             flags & OF_GPIO_ACTIVE_LOW;
 290                         pdata->button[i].wakeup =
 291                             !!of_get_property(child_node, "gpio-key,wakeup",
 292                                               NULL);
 293                         break;
 294
 295                 case TYPE_ADC:
 296                         if (of_property_read_u32
 297                             (child_node, "rockchip,adc_value", &adc_value)) {
 298                                 dev_err(&pdev->dev,
 299                                         "Missing rockchip,adc_value property in the DT.\n");
 300                                 ret = -EINVAL;
 301                                 goto error_ret;
 302                         }
 303                         pdata->button[i].adc_value = adc_value;
 304                         break;
 305
 306                 default:
 307                         dev_err(&pdev->dev,
 308                                 "Error rockchip,type property in the DT.\n");
 309                         ret = -EINVAL;
 310                         goto error_ret;
 311                 }
 312                 i++;
 313         }
 314
 315         return 0;
 316
 317 error_ret:
 318         return ret;
 319 }
 320
 321 static int keys_probe(struct platform_device *pdev)
 322 {
 323         struct device *dev = &pdev->dev;
 324         struct device_node *np = pdev->dev.of_node;
 325         struct rk_keys_drvdata *ddata = NULL;
 326         struct input_dev *input = NULL;
 327         int i, error = 0;
 328         int wakeup, key_num = 0;
 329
 330         key_num = of_get_child_count(np);
 331         if (key_num == 0)
 332                 dev_info(&pdev->dev, "no key defined\n");
 333
 334         ddata = devm_kzalloc(dev, sizeof(struct rk_keys_drvdata) +
 335                              key_num * sizeof(struct rk_keys_button),
 336                              GFP_KERNEL);
 337
 338         input = devm_input_allocate_device(dev);
 339         if (!ddata || !input) {
 340                 error = -ENOMEM;
 341                 return error;
 342         }
 343         platform_set_drvdata(pdev, ddata);
 344
 345         input->name = "rk29-keypad";    /* pdev->name; */
 346         input->phys = "gpio-keys/input0";
 347         input->dev.parent = dev;
 348
 349         input->id.bustype = BUS_HOST;
 350         input->id.vendor = 0x0001;
 351         input->id.product = 0x0001;
 352         input->id.version = 0x0100;
 353         ddata->input = input;
 354
 355         /* parse info from dt */
 356         ddata->nbuttons = key_num;
 357         error = rk_keys_parse_dt(ddata, pdev);
 358         if (error)
 359                 goto fail0;
 360
 361         /* Enable auto repeat feature of Linux input subsystem */
 362         if (ddata->rep)
 363                 __set_bit(EV_REP, input->evbit);
 364
 365         for (i = 0; i < ddata->nbuttons; i++) {
 366                 struct rk_keys_button *button = &ddata->button[i];
 367
 368                 if (button->code) {
 369                         setup_timer(&button->timer,
 370                                     keys_timer, (unsigned long)button);
 371                 }
 372
 373                 if (button->wakeup)
 374                         wakeup = 1;
 375
 376                 input_set_capability(input, EV_KEY, button->code);
 377         }
 378
 379         wake_lock_init(&ddata->wake_lock, WAKE_LOCK_SUSPEND, input->name);
 380
 381         for (i = 0; i < ddata->nbuttons; i++) {
 382                 struct rk_keys_button *button = &ddata->button[i];
 383
 384                 if (button->type == TYPE_GPIO) {
 385                         int irq;
 386
 387                         error =
 388                             devm_gpio_request(dev, button->gpio,
 389                                               button->desc ? : "keys");
 390                         if (error < 0) {
 391                                 pr_err("gpio-keys: failed to request GPIO %d, error %d\n",
 392                                        button->gpio, error);
 393                                 goto fail1;
 394                         }
 395
 396                         error = gpio_direction_input(button->gpio);
 397                         if (error < 0) {
 398                                 pr_err("gpio-keys: failed to configure input direction for GPIO %d, error %d\n",
 399                                        button->gpio, error);
 400                                 gpio_free(button->gpio);
 401                                 goto fail1;
 402                         }
 403
 404                         irq = gpio_to_irq(button->gpio);
 405                         if (irq < 0) {
 406                                 error = irq;
 407                                 pr_err("gpio-keys: Unable to get irq number for GPIO %d, error %d\n",
 408                                        button->gpio, error);
 409                                 gpio_free(button->gpio);
 410                                 goto fail1;
 411                         }
 412
 413                         error = devm_request_irq(dev, irq, keys_isr,
 414                                                  button->active_low ?
 415                                                  IRQF_TRIGGER_FALLING :
 416                                                  IRQF_TRIGGER_RISING,
 417                                                  button->desc ?
 418                                                  button->desc : "keys",
 419                                                  button);
 420                         if (error) {
 421                                 pr_err("gpio-keys: Unable to claim irq %d; error %d\n",
 422                                        irq, error);
 423                                 gpio_free(button->gpio);
 424                                 goto fail1;
 425                         }
 426                 }
 427         }
 428
 429         input_set_capability(input, EV_KEY, KEY_WAKEUP);
 430         device_init_wakeup(dev, wakeup);
 431
 432         error = input_register_device(input);
 433         if (error) {
 434                 pr_err("gpio-keys: Unable to register input device, error: %d\n",
 435                        error);
 436                 goto fail2;
 437         }
 438
 439         /* adc polling work */
 440         if (ddata->chan) {
 441                 INIT_DELAYED_WORK(&ddata->adc_poll_work, adc_key_poll);
 442                 schedule_delayed_work(&ddata->adc_poll_work,
 443                                       ADC_SAMPLE_JIFFIES);
 444         }
 445
 446         spdata = ddata;
 447         sinput_dev = input;
 448         return error;
 449
 450 fail2:
 451         device_init_wakeup(dev, 0);
 452 fail1:
 453         wake_lock_destroy(&ddata->wake_lock);
 454         while (--i >= 0)
 455                 del_timer_sync(&ddata->button[i].timer);
 456 fail0:
 457         platform_set_drvdata(pdev, NULL);
 458
 459         return error;
 460 }
 461
 462 static int keys_remove(struct platform_device *pdev)
 463 {
 464         struct device *dev = &pdev->dev;
 465         struct rk_keys_drvdata *ddata = dev_get_drvdata(dev);
 466         struct input_dev *input = ddata->input;
 467         int i;
 468
 469         device_init_wakeup(dev, 0);
 470         for (i = 0; i < ddata->nbuttons; i++)
 471                 del_timer_sync(&ddata->button[i].timer);
 472         if (ddata->chan)
 473                 cancel_delayed_work_sync(&ddata->adc_poll_work);
 474         input_unregister_device(input);
 475         wake_lock_destroy(&ddata->wake_lock);
 476
 477         sinput_dev = NULL;
 478         spdata = NULL;
 479
 480         return 0;
 481 }
 482
 483 #ifdef CONFIG_PM
 484 static int keys_suspend(struct device *dev)
 485 {
 486         struct rk_keys_drvdata *ddata = dev_get_drvdata(dev);
 487         int i;
 488
 489         ddata->in_suspend = true;
 490         if (device_may_wakeup(dev)) {
 491                 for (i = 0; i < ddata->nbuttons; i++) {
 492                         struct rk_keys_button *button = ddata->button + i;
 493
 494                         if (button->wakeup)
 495                                 enable_irq_wake(gpio_to_irq(button->gpio));
 496                 }
 497         }
 498
 499         return 0;
 500 }
 501
 502 static int keys_resume(struct device *dev)
 503 {
 504         struct rk_keys_drvdata *ddata = dev_get_drvdata(dev);
 505         int i;
 506
 507         if (device_may_wakeup(dev)) {
 508                 for (i = 0; i < ddata->nbuttons; i++) {
 509                         struct rk_keys_button *button = ddata->button + i;
 510
 511                         if (button->wakeup)
 512                                 disable_irq_wake(gpio_to_irq(button->gpio));
 513                 }
 514                 preempt_disable();
 515                 /* for call resend_irqs, which may call keys_isr */
 516                 if (local_softirq_pending())
 517                         do_softirq();
 518                 preempt_enable_no_resched();
 519         }
 520
 521         ddata->in_suspend = false;
 522
 523         return 0;
 524 }
 525
 526 static const struct dev_pm_ops keys_pm_ops = {
 527         .suspend        = keys_suspend,
 528         .resume         = keys_resume,
 529 };
 530 #endif
 531
 532 static struct platform_driver keys_device_driver = {
 533         .probe          = keys_probe,
 534         .remove         = keys_remove,
 535         .driver         = {
 536                 .name   = "rk-keypad",
 537                 .owner  = THIS_MODULE,
 538                 .of_match_table = rk_key_match,
 539 #ifdef CONFIG_PM
 540                 .pm     = &keys_pm_ops,
 541 #endif
 542         }
 543 };
 544
 545 module_platform_driver(keys_device_driver);