drivers/rtc/rtc-rx8010.c

   1 /*
   2  * Driver for the Epson RTC module RX-8010 SJ
   3  *
   4  * Copyright(C) Timesys Corporation 2015
   5  * Copyright(C) General Electric Company 2015
   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
  13 #include <linux/bcd.h>
  14 #include <linux/bitops.h>
  15 #include <linux/i2c.h>
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/rtc.h>
  19
  20 #define RX8010_SEC     0x10
  21 #define RX8010_MIN     0x11
  22 #define RX8010_HOUR    0x12
  23 #define RX8010_WDAY    0x13
  24 #define RX8010_MDAY    0x14
  25 #define RX8010_MONTH   0x15
  26 #define RX8010_YEAR    0x16
  27 #define RX8010_YEAR    0x16
  28 #define RX8010_RESV17  0x17
  29 #define RX8010_ALMIN   0x18
  30 #define RX8010_ALHOUR  0x19
  31 #define RX8010_ALWDAY  0x1A
  32 #define RX8010_TCOUNT0 0x1B
  33 #define RX8010_TCOUNT1 0x1C
  34 #define RX8010_EXT     0x1D
  35 #define RX8010_FLAG    0x1E
  36 #define RX8010_CTRL    0x1F
  37 /* 0x20 to 0x2F are user registers */
  38 #define RX8010_RESV30  0x30
  39 #define RX8010_RESV31  0x32
  40 #define RX8010_IRQ     0x32
  41
  42 #define RX8010_EXT_WADA  BIT(3)
  43
  44 #define RX8010_FLAG_VLF  BIT(1)
  45 #define RX8010_FLAG_AF   BIT(3)
  46 #define RX8010_FLAG_TF   BIT(4)
  47 #define RX8010_FLAG_UF   BIT(5)
  48
  49 #define RX8010_CTRL_AIE  BIT(3)
  50 #define RX8010_CTRL_UIE  BIT(5)
  51 #define RX8010_CTRL_STOP BIT(6)
  52 #define RX8010_CTRL_TEST BIT(7)
  53
  54 #define RX8010_ALARM_AE  BIT(7)
  55
  56 static const struct i2c_device_id rx8010_id[] = {
  57         { "rx8010", 0 },
  58         { }
  59 };
  60 MODULE_DEVICE_TABLE(i2c, rx8010_id);
  61
  62 static const struct of_device_id rx8010_of_match[] = {
  63         { .compatible = "epson,rx8010" },
  64         { }
  65 };
  66 MODULE_DEVICE_TABLE(of, rx8010_of_match);
  67
  68 struct rx8010_data {
  69         struct i2c_client *client;
  70         struct rtc_device *rtc;
  71         u8 ctrlreg;
  72 };
  73
  74 static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id)
  75 {
  76         struct i2c_client *client = dev_id;
  77         struct rx8010_data *rx8010 = i2c_get_clientdata(client);
  78         int flagreg;
  79
  80         mutex_lock(&rx8010->rtc->ops_lock);
  81
  82         flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
  83
  84         if (flagreg <= 0) {
  85                 mutex_unlock(&rx8010->rtc->ops_lock);
  86                 return IRQ_NONE;
  87         }
  88
  89         if (flagreg & RX8010_FLAG_VLF)
  90                 dev_warn(&client->dev, "Frequency stop detected\n");
  91
  92         if (flagreg & RX8010_FLAG_TF) {
  93                 flagreg &= ~RX8010_FLAG_TF;
  94                 rtc_update_irq(rx8010->rtc, 1, RTC_PF | RTC_IRQF);
  95         }
  96
  97         if (flagreg & RX8010_FLAG_AF) {
  98                 flagreg &= ~RX8010_FLAG_AF;
  99                 rtc_update_irq(rx8010->rtc, 1, RTC_AF | RTC_IRQF);
 100         }
 101
 102         if (flagreg & RX8010_FLAG_UF) {
 103                 flagreg &= ~RX8010_FLAG_UF;
 104                 rtc_update_irq(rx8010->rtc, 1, RTC_UF | RTC_IRQF);
 105         }
 106
 107         i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg);
 108
 109         mutex_unlock(&rx8010->rtc->ops_lock);
 110         return IRQ_HANDLED;
 111 }
 112
 113 static int rx8010_get_time(struct device *dev, struct rtc_time *dt)
 114 {
 115         struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 116         u8 date[7];
 117         int flagreg;
 118         int err;
 119
 120         flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
 121         if (flagreg < 0)
 122                 return flagreg;
 123
 124         if (flagreg & RX8010_FLAG_VLF) {
 125                 dev_warn(dev, "Frequency stop detected\n");
 126                 return -EINVAL;
 127         }
 128
 129         err = i2c_smbus_read_i2c_block_data(rx8010->client, RX8010_SEC,
 130                                             7, date);
 131         if (err != 7)
 132                 return err < 0 ? err : -EIO;
 133
 134         dt->tm_sec = bcd2bin(date[RX8010_SEC - RX8010_SEC] & 0x7f);
 135         dt->tm_min = bcd2bin(date[RX8010_MIN - RX8010_SEC] & 0x7f);
 136         dt->tm_hour = bcd2bin(date[RX8010_HOUR - RX8010_SEC] & 0x3f);
 137         dt->tm_mday = bcd2bin(date[RX8010_MDAY - RX8010_SEC] & 0x3f);
 138         dt->tm_mon = bcd2bin(date[RX8010_MONTH - RX8010_SEC] & 0x1f) - 1;
 139         dt->tm_year = bcd2bin(date[RX8010_YEAR - RX8010_SEC]) + 100;
 140         dt->tm_wday = ffs(date[RX8010_WDAY - RX8010_SEC] & 0x7f);
 141
 142         return rtc_valid_tm(dt);
 143 }
 144
 145 static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
 146 {
 147         struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 148         u8 date[7];
 149         int ctrl, flagreg;
 150         int ret;
 151
 152         if ((dt->tm_year < 100) || (dt->tm_year > 199))
 153                 return -EINVAL;
 154
 155         /* set STOP bit before changing clock/calendar */
 156         ctrl = i2c_smbus_read_byte_data(rx8010->client, RX8010_CTRL);
 157         if (ctrl < 0)
 158                 return ctrl;
 159         rx8010->ctrlreg = ctrl | RX8010_CTRL_STOP;
 160         ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
 161                                         rx8010->ctrlreg);
 162         if (ret < 0)
 163                 return ret;
 164
 165         date[RX8010_SEC - RX8010_SEC] = bin2bcd(dt->tm_sec);
 166         date[RX8010_MIN - RX8010_SEC] = bin2bcd(dt->tm_min);
 167         date[RX8010_HOUR - RX8010_SEC] = bin2bcd(dt->tm_hour);
 168         date[RX8010_MDAY - RX8010_SEC] = bin2bcd(dt->tm_mday);
 169         date[RX8010_MONTH - RX8010_SEC] = bin2bcd(dt->tm_mon + 1);
 170         date[RX8010_YEAR - RX8010_SEC] = bin2bcd(dt->tm_year - 100);
 171         date[RX8010_WDAY - RX8010_SEC] = bin2bcd(1 << dt->tm_wday);
 172
 173         ret = i2c_smbus_write_i2c_block_data(rx8010->client,
 174                                              RX8010_SEC, 7, date);
 175         if (ret < 0)
 176                 return ret;
 177
 178         /* clear STOP bit after changing clock/calendar */
 179         ctrl = i2c_smbus_read_byte_data(rx8010->client, RX8010_CTRL);
 180         if (ctrl < 0)
 181                 return ctrl;
 182         rx8010->ctrlreg = ctrl & ~RX8010_CTRL_STOP;
 183         ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
 184                                         rx8010->ctrlreg);
 185         if (ret < 0)
 186                 return ret;
 187
 188         flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
 189         if (flagreg < 0) {
 190                 return flagreg;
 191         }
 192
 193         if (flagreg & RX8010_FLAG_VLF)
 194                 ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG,
 195                                                 flagreg & ~RX8010_FLAG_VLF);
 196
 197         return 0;
 198 }
 199
 200 static int rx8010_init_client(struct i2c_client *client)
 201 {
 202         struct rx8010_data *rx8010 = i2c_get_clientdata(client);
 203         u8 ctrl[2];
 204         int need_clear = 0, err = 0;
 205
 206         /* Initialize reserved registers as specified in datasheet */
 207         err = i2c_smbus_write_byte_data(client, RX8010_RESV17, 0xD8);
 208         if (err < 0)
 209                 return err;
 210
 211         err = i2c_smbus_write_byte_data(client, RX8010_RESV30, 0x00);
 212         if (err < 0)
 213                 return err;
 214
 215         err = i2c_smbus_write_byte_data(client, RX8010_RESV31, 0x08);
 216         if (err < 0)
 217                 return err;
 218
 219         err = i2c_smbus_write_byte_data(client, RX8010_IRQ, 0x00);
 220         if (err < 0)
 221                 return err;
 222
 223         err = i2c_smbus_read_i2c_block_data(rx8010->client, RX8010_FLAG,
 224                                             2, ctrl);
 225         if (err != 2)
 226                 return err < 0 ? err : -EIO;
 227
 228         if (ctrl[0] & RX8010_FLAG_VLF)
 229                 dev_warn(&client->dev, "Frequency stop was detected\n");
 230
 231         if (ctrl[0] & RX8010_FLAG_AF) {
 232                 dev_warn(&client->dev, "Alarm was detected\n");
 233                 need_clear = 1;
 234         }
 235
 236         if (ctrl[0] & RX8010_FLAG_TF)
 237                 need_clear = 1;
 238
 239         if (ctrl[0] & RX8010_FLAG_UF)
 240                 need_clear = 1;
 241
 242         if (need_clear) {
 243                 ctrl[0] &= ~(RX8010_FLAG_AF | RX8010_FLAG_TF | RX8010_FLAG_UF);
 244                 err = i2c_smbus_write_byte_data(client, RX8010_FLAG, ctrl[0]);
 245                 if (err < 0)
 246                         return err;
 247         }
 248
 249         rx8010->ctrlreg = (ctrl[1] & ~RX8010_CTRL_TEST);
 250
 251         return err;
 252 }
 253
 254 static int rx8010_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 255 {
 256         struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 257         struct i2c_client *client = rx8010->client;
 258         u8 alarmvals[3];
 259         int flagreg;
 260         int err;
 261
 262         err = i2c_smbus_read_i2c_block_data(client, RX8010_ALMIN, 3, alarmvals);
 263         if (err != 3)
 264                 return err < 0 ? err : -EIO;
 265
 266         flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
 267         if (flagreg < 0)
 268                 return flagreg;
 269
 270         t->time.tm_sec = 0;
 271         t->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
 272         t->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
 273
 274         if (!(alarmvals[2] & RX8010_ALARM_AE))
 275                 t->time.tm_mday = bcd2bin(alarmvals[2] & 0x7f);
 276
 277         t->enabled = !!(rx8010->ctrlreg & RX8010_CTRL_AIE);
 278         t->pending = (flagreg & RX8010_FLAG_AF) && t->enabled;
 279
 280         return err;
 281 }
 282
 283 static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 284 {
 285         struct i2c_client *client = to_i2c_client(dev);
 286         struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 287         u8 alarmvals[3];
 288         int extreg, flagreg;
 289         int err;
 290
 291         flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
 292         if (flagreg < 0) {
 293                 return flagreg;
 294         }
 295
 296         if (rx8010->ctrlreg & (RX8010_CTRL_AIE | RX8010_CTRL_UIE)) {
 297                 rx8010->ctrlreg &= ~(RX8010_CTRL_AIE | RX8010_CTRL_UIE);
 298                 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
 299                                                 rx8010->ctrlreg);
 300                 if (err < 0) {
 301                         return err;
 302                 }
 303         }
 304
 305         flagreg &= ~RX8010_FLAG_AF;
 306         err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg);
 307         if (err < 0)
 308                 return err;
 309
 310         alarmvals[0] = bin2bcd(t->time.tm_min);
 311         alarmvals[1] = bin2bcd(t->time.tm_hour);
 312         alarmvals[2] = bin2bcd(t->time.tm_mday);
 313
 314         err = i2c_smbus_write_i2c_block_data(rx8010->client, RX8010_ALMIN,
 315                                              2, alarmvals);
 316         if (err < 0)
 317                 return err;
 318
 319         extreg = i2c_smbus_read_byte_data(client, RX8010_EXT);
 320         if (extreg < 0)
 321                 return extreg;
 322
 323         extreg |= RX8010_EXT_WADA;
 324         err = i2c_smbus_write_byte_data(rx8010->client, RX8010_EXT, extreg);
 325         if (err < 0)
 326                 return err;
 327
 328         if (alarmvals[2] == 0)
 329                 alarmvals[2] |= RX8010_ALARM_AE;
 330
 331         err = i2c_smbus_write_byte_data(rx8010->client, RX8010_ALWDAY,
 332                                         alarmvals[2]);
 333         if (err < 0)
 334                 return err;
 335
 336         if (t->enabled) {
 337                 if (rx8010->rtc->uie_rtctimer.enabled)
 338                         rx8010->ctrlreg |= RX8010_CTRL_UIE;
 339                 if (rx8010->rtc->aie_timer.enabled)
 340                         rx8010->ctrlreg |=
 341                                 (RX8010_CTRL_AIE | RX8010_CTRL_UIE);
 342
 343                 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
 344                                                 rx8010->ctrlreg);
 345                 if (err < 0)
 346                         return err;
 347         }
 348
 349         return 0;
 350 }
 351
 352 static int rx8010_alarm_irq_enable(struct device *dev,
 353                                    unsigned int enabled)
 354 {
 355         struct i2c_client *client = to_i2c_client(dev);
 356         struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 357         int flagreg;
 358         u8 ctrl;
 359         int err;
 360
 361         ctrl = rx8010->ctrlreg;
 362
 363         if (enabled) {
 364                 if (rx8010->rtc->uie_rtctimer.enabled)
 365                         ctrl |= RX8010_CTRL_UIE;
 366                 if (rx8010->rtc->aie_timer.enabled)
 367                         ctrl |= (RX8010_CTRL_AIE | RX8010_CTRL_UIE);
 368         } else {
 369                 if (!rx8010->rtc->uie_rtctimer.enabled)
 370                         ctrl &= ~RX8010_CTRL_UIE;
 371                 if (!rx8010->rtc->aie_timer.enabled)
 372                         ctrl &= ~RX8010_CTRL_AIE;
 373         }
 374
 375         flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
 376         if (flagreg < 0)
 377                 return flagreg;
 378
 379         flagreg &= ~RX8010_FLAG_AF;
 380         err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg);
 381         if (err < 0)
 382                 return err;
 383
 384         if (ctrl != rx8010->ctrlreg) {
 385                 rx8010->ctrlreg = ctrl;
 386                 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
 387                                                 rx8010->ctrlreg);
 388                 if (err < 0)
 389                         return err;
 390         }
 391
 392         return 0;
 393 }
 394
 395 static int rx8010_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 396 {
 397         struct i2c_client *client = to_i2c_client(dev);
 398         struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 399         int ret, tmp;
 400         int flagreg;
 401
 402         switch (cmd) {
 403         case RTC_VL_READ:
 404                 flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
 405                 if (flagreg < 0)
 406                         return flagreg;
 407
 408                 tmp = !!(flagreg & RX8010_FLAG_VLF);
 409                 if (copy_to_user((void __user *)arg, &tmp, sizeof(int)))
 410                         return -EFAULT;
 411
 412                 return 0;
 413
 414         case RTC_VL_CLR:
 415                 flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
 416                 if (flagreg < 0) {
 417                         return flagreg;
 418                 }
 419
 420                 flagreg &= ~RX8010_FLAG_VLF;
 421                 ret = i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg);
 422                 if (ret < 0)
 423                         return ret;
 424
 425                 return 0;
 426
 427         default:
 428                 return -ENOIOCTLCMD;
 429         }
 430 }
 431
 432 static struct rtc_class_ops rx8010_rtc_ops = {
 433         .read_time = rx8010_get_time,
 434         .set_time = rx8010_set_time,
 435         .ioctl = rx8010_ioctl,
 436 };
 437
 438 static int rx8010_probe(struct i2c_client *client,
 439                         const struct i2c_device_id *id)
 440 {
 441         struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 442         struct rx8010_data *rx8010;
 443         int err = 0;
 444
 445         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
 446                 | I2C_FUNC_SMBUS_I2C_BLOCK)) {
 447                 dev_err(&adapter->dev, "doesn't support required functionality\n");
 448                 return -EIO;
 449         }
 450
 451         rx8010 = devm_kzalloc(&client->dev, sizeof(struct rx8010_data),
 452                               GFP_KERNEL);
 453         if (!rx8010)
 454                 return -ENOMEM;
 455
 456         rx8010->client = client;
 457         i2c_set_clientdata(client, rx8010);
 458
 459         err = rx8010_init_client(client);
 460         if (err)
 461                 return err;
 462
 463         if (client->irq > 0) {
 464                 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
 465                 err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
 466                                                 rx8010_irq_1_handler,
 467                                                 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 468                                                 "rx8010", client);
 469
 470                 if (err) {
 471                         dev_err(&client->dev, "unable to request IRQ\n");
 472                         client->irq = 0;
 473                 } else {
 474                         rx8010_rtc_ops.read_alarm = rx8010_read_alarm;
 475                         rx8010_rtc_ops.set_alarm = rx8010_set_alarm;
 476                         rx8010_rtc_ops.alarm_irq_enable = rx8010_alarm_irq_enable;
 477                 }
 478         }
 479
 480         rx8010->rtc = devm_rtc_device_register(&client->dev, client->name,
 481                 &rx8010_rtc_ops, THIS_MODULE);
 482
 483         if (IS_ERR(rx8010->rtc)) {
 484                 dev_err(&client->dev, "unable to register the class device\n");
 485                 return PTR_ERR(rx8010->rtc);
 486         }
 487
 488         rx8010->rtc->max_user_freq = 1;
 489
 490         return err;
 491 }
 492
 493 static struct i2c_driver rx8010_driver = {
 494         .driver = {
 495                 .name = "rtc-rx8010",
 496                 .of_match_table = of_match_ptr(rx8010_of_match),
 497         },
 498         .probe          = rx8010_probe,
 499         .id_table       = rx8010_id,
 500 };
 501
 502 module_i2c_driver(rx8010_driver);
 503
 504 MODULE_AUTHOR("Akshay Bhat <akshay.bhat@timesys.com>");
 505 MODULE_DESCRIPTION("Epson RX8010SJ RTC driver");
 506 MODULE_LICENSE("GPL v2");