drivers/rtc/rtc-rx8010.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Driver for the Epson RTC module RX-8010 SJ
   4  *
   5  * Copyright(C) Timesys Corporation 2015
   6  * Copyright(C) General Electric Company 2015
   7  */
   8
   9 #include <linux/bcd.h>
  10 #include <linux/bitops.h>
  11 #include <linux/i2c.h>
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/regmap.h>
  15 #include <linux/rtc.h>
  16
  17 #define RX8010_SEC              0x10
  18 #define RX8010_MIN              0x11
  19 #define RX8010_HOUR             0x12
  20 #define RX8010_WDAY             0x13
  21 #define RX8010_MDAY             0x14
  22 #define RX8010_MONTH            0x15
  23 #define RX8010_YEAR             0x16
  24 #define RX8010_RESV17           0x17
  25 #define RX8010_ALMIN            0x18
  26 #define RX8010_ALHOUR           0x19
  27 #define RX8010_ALWDAY           0x1A
  28 #define RX8010_TCOUNT0          0x1B
  29 #define RX8010_TCOUNT1          0x1C
  30 #define RX8010_EXT              0x1D
  31 #define RX8010_FLAG             0x1E
  32 #define RX8010_CTRL             0x1F
  33 /* 0x20 to 0x2F are user registers */
  34 #define RX8010_RESV30           0x30
  35 #define RX8010_RESV31           0x31
  36 #define RX8010_IRQ              0x32
  37
  38 #define RX8010_EXT_WADA         BIT(3)
  39
  40 #define RX8010_FLAG_VLF         BIT(1)
  41 #define RX8010_FLAG_AF          BIT(3)
  42 #define RX8010_FLAG_TF          BIT(4)
  43 #define RX8010_FLAG_UF          BIT(5)
  44
  45 #define RX8010_CTRL_AIE         BIT(3)
  46 #define RX8010_CTRL_UIE         BIT(5)
  47 #define RX8010_CTRL_STOP        BIT(6)
  48 #define RX8010_CTRL_TEST        BIT(7)
  49
  50 #define RX8010_ALARM_AE         BIT(7)
  51
  52 static const struct i2c_device_id rx8010_id[] = {
  53         { "rx8010", 0 },
  54         { }
  55 };
  56 MODULE_DEVICE_TABLE(i2c, rx8010_id);
  57
  58 static const __maybe_unused struct of_device_id rx8010_of_match[] = {
  59         { .compatible = "epson,rx8010" },
  60         { }
  61 };
  62 MODULE_DEVICE_TABLE(of, rx8010_of_match);
  63
  64 struct rx8010_data {
  65         struct regmap *regs;
  66         struct rtc_device *rtc;
  67         u8 ctrlreg;
  68 };
  69
  70 static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id)
  71 {
  72         struct i2c_client *client = dev_id;
  73         struct rx8010_data *rx8010 = i2c_get_clientdata(client);
  74         int flagreg, err;
  75
  76         rtc_lock(rx8010->rtc);
  77
  78         err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);
  79         if (err) {
  80                 rtc_unlock(rx8010->rtc);
  81                 return IRQ_NONE;
  82         }
  83
  84         if (flagreg & RX8010_FLAG_VLF)
  85                 dev_warn(&client->dev, "Frequency stop detected\n");
  86
  87         if (flagreg & RX8010_FLAG_TF) {
  88                 flagreg &= ~RX8010_FLAG_TF;
  89                 rtc_update_irq(rx8010->rtc, 1, RTC_PF | RTC_IRQF);
  90         }
  91
  92         if (flagreg & RX8010_FLAG_AF) {
  93                 flagreg &= ~RX8010_FLAG_AF;
  94                 rtc_update_irq(rx8010->rtc, 1, RTC_AF | RTC_IRQF);
  95         }
  96
  97         if (flagreg & RX8010_FLAG_UF) {
  98                 flagreg &= ~RX8010_FLAG_UF;
  99                 rtc_update_irq(rx8010->rtc, 1, RTC_UF | RTC_IRQF);
 100         }
 101
 102         err = regmap_write(rx8010->regs, RX8010_FLAG, flagreg);
 103         rtc_unlock(rx8010->rtc);
 104         return err ? IRQ_NONE : IRQ_HANDLED;
 105 }
 106
 107 static int rx8010_get_time(struct device *dev, struct rtc_time *dt)
 108 {
 109         struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 110         u8 date[RX8010_YEAR - RX8010_SEC + 1];
 111         int flagreg, err;
 112
 113         err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);
 114         if (err)
 115                 return err;
 116
 117         if (flagreg & RX8010_FLAG_VLF) {
 118                 dev_warn(dev, "Frequency stop detected\n");
 119                 return -EINVAL;
 120         }
 121
 122         err = regmap_bulk_read(rx8010->regs, RX8010_SEC, date, sizeof(date));
 123         if (err)
 124                 return err;
 125
 126         dt->tm_sec = bcd2bin(date[RX8010_SEC - RX8010_SEC] & 0x7f);
 127         dt->tm_min = bcd2bin(date[RX8010_MIN - RX8010_SEC] & 0x7f);
 128         dt->tm_hour = bcd2bin(date[RX8010_HOUR - RX8010_SEC] & 0x3f);
 129         dt->tm_mday = bcd2bin(date[RX8010_MDAY - RX8010_SEC] & 0x3f);
 130         dt->tm_mon = bcd2bin(date[RX8010_MONTH - RX8010_SEC] & 0x1f) - 1;
 131         dt->tm_year = bcd2bin(date[RX8010_YEAR - RX8010_SEC]) + 100;
 132         dt->tm_wday = ffs(date[RX8010_WDAY - RX8010_SEC] & 0x7f);
 133
 134         return 0;
 135 }
 136
 137 static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
 138 {
 139         struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 140         u8 date[RX8010_YEAR - RX8010_SEC + 1];
 141         int err;
 142
 143         /* set STOP bit before changing clock/calendar */
 144         err = regmap_set_bits(rx8010->regs, RX8010_CTRL, RX8010_CTRL_STOP);
 145         if (err)
 146                 return err;
 147
 148         date[RX8010_SEC - RX8010_SEC] = bin2bcd(dt->tm_sec);
 149         date[RX8010_MIN - RX8010_SEC] = bin2bcd(dt->tm_min);
 150         date[RX8010_HOUR - RX8010_SEC] = bin2bcd(dt->tm_hour);
 151         date[RX8010_MDAY - RX8010_SEC] = bin2bcd(dt->tm_mday);
 152         date[RX8010_MONTH - RX8010_SEC] = bin2bcd(dt->tm_mon + 1);
 153         date[RX8010_YEAR - RX8010_SEC] = bin2bcd(dt->tm_year - 100);
 154         date[RX8010_WDAY - RX8010_SEC] = bin2bcd(1 << dt->tm_wday);
 155
 156         err = regmap_bulk_write(rx8010->regs, RX8010_SEC, date, sizeof(date));
 157         if (err)
 158                 return err;
 159
 160         /* clear STOP bit after changing clock/calendar */
 161         err = regmap_clear_bits(rx8010->regs, RX8010_CTRL, RX8010_CTRL_STOP);
 162         if (err)
 163                 return err;
 164
 165         err = regmap_clear_bits(rx8010->regs, RX8010_FLAG, RX8010_FLAG_VLF);
 166         if (err)
 167                 return err;
 168
 169         return 0;
 170 }
 171
 172 static int rx8010_init(struct device *dev)
 173 {
 174         struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 175         u8 ctrl[2];
 176         int need_clear = 0, err;
 177
 178         /* Initialize reserved registers as specified in datasheet */
 179         err = regmap_write(rx8010->regs, RX8010_RESV17, 0xD8);
 180         if (err)
 181                 return err;
 182
 183         err = regmap_write(rx8010->regs, RX8010_RESV30, 0x00);
 184         if (err)
 185                 return err;
 186
 187         err = regmap_write(rx8010->regs, RX8010_RESV31, 0x08);
 188         if (err)
 189                 return err;
 190
 191         err = regmap_write(rx8010->regs, RX8010_IRQ, 0x00);
 192         if (err)
 193                 return err;
 194
 195         err = regmap_bulk_read(rx8010->regs, RX8010_FLAG, ctrl, 2);
 196         if (err)
 197                 return err;
 198
 199         if (ctrl[0] & RX8010_FLAG_VLF)
 200                 dev_warn(dev, "Frequency stop was detected\n");
 201
 202         if (ctrl[0] & RX8010_FLAG_AF) {
 203                 dev_warn(dev, "Alarm was detected\n");
 204                 need_clear = 1;
 205         }
 206
 207         if (ctrl[0] & RX8010_FLAG_TF)
 208                 need_clear = 1;
 209
 210         if (ctrl[0] & RX8010_FLAG_UF)
 211                 need_clear = 1;
 212
 213         if (need_clear) {
 214                 ctrl[0] &= ~(RX8010_FLAG_AF | RX8010_FLAG_TF | RX8010_FLAG_UF);
 215                 err = regmap_write(rx8010->regs, RX8010_FLAG, ctrl[0]);
 216                 if (err)
 217                         return err;
 218         }
 219
 220         rx8010->ctrlreg = (ctrl[1] & ~RX8010_CTRL_TEST);
 221
 222         return 0;
 223 }
 224
 225 static int rx8010_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 226 {
 227         struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 228         u8 alarmvals[3];
 229         int flagreg, err;
 230
 231         err = regmap_bulk_read(rx8010->regs, RX8010_ALMIN, alarmvals, 3);
 232         if (err)
 233                 return err;
 234
 235         err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);
 236         if (err)
 237                 return err;
 238
 239         t->time.tm_sec = 0;
 240         t->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
 241         t->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
 242
 243         if (!(alarmvals[2] & RX8010_ALARM_AE))
 244                 t->time.tm_mday = bcd2bin(alarmvals[2] & 0x7f);
 245
 246         t->enabled = !!(rx8010->ctrlreg & RX8010_CTRL_AIE);
 247         t->pending = (flagreg & RX8010_FLAG_AF) && t->enabled;
 248
 249         return 0;
 250 }
 251
 252 static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 253 {
 254         struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 255         u8 alarmvals[3];
 256         int err;
 257
 258         if (rx8010->ctrlreg & (RX8010_CTRL_AIE | RX8010_CTRL_UIE)) {
 259                 rx8010->ctrlreg &= ~(RX8010_CTRL_AIE | RX8010_CTRL_UIE);
 260                 err = regmap_write(rx8010->regs, RX8010_CTRL, rx8010->ctrlreg);
 261                 if (err)
 262                         return err;
 263         }
 264
 265         err = regmap_clear_bits(rx8010->regs, RX8010_FLAG, RX8010_FLAG_AF);
 266         if (err)
 267                 return err;
 268
 269         alarmvals[0] = bin2bcd(t->time.tm_min);
 270         alarmvals[1] = bin2bcd(t->time.tm_hour);
 271         alarmvals[2] = bin2bcd(t->time.tm_mday);
 272
 273         err = regmap_bulk_write(rx8010->regs, RX8010_ALMIN, alarmvals, 2);
 274         if (err)
 275                 return err;
 276
 277         err = regmap_clear_bits(rx8010->regs, RX8010_EXT, RX8010_EXT_WADA);
 278         if (err)
 279                 return err;
 280
 281         if (alarmvals[2] == 0)
 282                 alarmvals[2] |= RX8010_ALARM_AE;
 283
 284         err = regmap_write(rx8010->regs, RX8010_ALWDAY, alarmvals[2]);
 285         if (err)
 286                 return err;
 287
 288         if (t->enabled) {
 289                 if (rx8010->rtc->uie_rtctimer.enabled)
 290                         rx8010->ctrlreg |= RX8010_CTRL_UIE;
 291                 if (rx8010->rtc->aie_timer.enabled)
 292                         rx8010->ctrlreg |=
 293                                 (RX8010_CTRL_AIE | RX8010_CTRL_UIE);
 294
 295                 err = regmap_write(rx8010->regs, RX8010_CTRL, rx8010->ctrlreg);
 296                 if (err)
 297                         return err;
 298         }
 299
 300         return 0;
 301 }
 302
 303 static int rx8010_alarm_irq_enable(struct device *dev,
 304                                    unsigned int enabled)
 305 {
 306         struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 307         int err;
 308         u8 ctrl;
 309
 310         ctrl = rx8010->ctrlreg;
 311
 312         if (enabled) {
 313                 if (rx8010->rtc->uie_rtctimer.enabled)
 314                         ctrl |= RX8010_CTRL_UIE;
 315                 if (rx8010->rtc->aie_timer.enabled)
 316                         ctrl |= (RX8010_CTRL_AIE | RX8010_CTRL_UIE);
 317         } else {
 318                 if (!rx8010->rtc->uie_rtctimer.enabled)
 319                         ctrl &= ~RX8010_CTRL_UIE;
 320                 if (!rx8010->rtc->aie_timer.enabled)
 321                         ctrl &= ~RX8010_CTRL_AIE;
 322         }
 323
 324         err = regmap_clear_bits(rx8010->regs, RX8010_FLAG, RX8010_FLAG_AF);
 325         if (err)
 326                 return err;
 327
 328         if (ctrl != rx8010->ctrlreg) {
 329                 rx8010->ctrlreg = ctrl;
 330                 err = regmap_write(rx8010->regs, RX8010_CTRL, rx8010->ctrlreg);
 331                 if (err)
 332                         return err;
 333         }
 334
 335         return 0;
 336 }
 337
 338 static int rx8010_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 339 {
 340         struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 341         int tmp, flagreg, err;
 342
 343         switch (cmd) {
 344         case RTC_VL_READ:
 345                 err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);
 346                 if (err)
 347                         return err;
 348
 349                 tmp = flagreg & RX8010_FLAG_VLF ? RTC_VL_DATA_INVALID : 0;
 350                 return put_user(tmp, (unsigned int __user *)arg);
 351
 352         default:
 353                 return -ENOIOCTLCMD;
 354         }
 355 }
 356
 357 static const struct rtc_class_ops rx8010_rtc_ops = {
 358         .read_time = rx8010_get_time,
 359         .set_time = rx8010_set_time,
 360         .ioctl = rx8010_ioctl,
 361         .read_alarm = rx8010_read_alarm,
 362         .set_alarm = rx8010_set_alarm,
 363         .alarm_irq_enable = rx8010_alarm_irq_enable,
 364 };
 365
 366 static const struct regmap_config rx8010_regmap_config = {
 367         .name = "rx8010-rtc",
 368         .reg_bits = 8,
 369         .val_bits = 8,
 370 };
 371
 372 static int rx8010_probe(struct i2c_client *client)
 373 {
 374         struct device *dev = &client->dev;
 375         struct rx8010_data *rx8010;
 376         int err = 0;
 377
 378         rx8010 = devm_kzalloc(dev, sizeof(*rx8010), GFP_KERNEL);
 379         if (!rx8010)
 380                 return -ENOMEM;
 381
 382         i2c_set_clientdata(client, rx8010);
 383
 384         rx8010->regs = devm_regmap_init_i2c(client, &rx8010_regmap_config);
 385         if (IS_ERR(rx8010->regs))
 386                 return PTR_ERR(rx8010->regs);
 387
 388         err = rx8010_init(dev);
 389         if (err)
 390                 return err;
 391
 392         rx8010->rtc = devm_rtc_allocate_device(dev);
 393         if (IS_ERR(rx8010->rtc))
 394                 return PTR_ERR(rx8010->rtc);
 395
 396         if (client->irq > 0) {
 397                 unsigned long irqflags = IRQF_TRIGGER_LOW;
 398
 399                 if (dev_fwnode(&client->dev))
 400                         irqflags = 0;
 401
 402                 err = devm_request_threaded_irq(dev, client->irq, NULL,
 403                                                 rx8010_irq_1_handler,
 404                                                 irqflags | IRQF_ONESHOT,
 405                                                 "rx8010", client);
 406                 if (err) {
 407                         dev_err(dev, "unable to request IRQ\n");
 408                         return err;
 409                 }
 410         } else {
 411                 clear_bit(RTC_FEATURE_ALARM, rx8010->rtc->features);
 412         }
 413
 414         rx8010->rtc->ops = &rx8010_rtc_ops;
 415         rx8010->rtc->max_user_freq = 1;
 416         rx8010->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 417         rx8010->rtc->range_max = RTC_TIMESTAMP_END_2099;
 418
 419         return devm_rtc_register_device(rx8010->rtc);
 420 }
 421
 422 static struct i2c_driver rx8010_driver = {
 423         .driver = {
 424                 .name = "rtc-rx8010",
 425                 .of_match_table = of_match_ptr(rx8010_of_match),
 426         },
 427         .probe          = rx8010_probe,
 428         .id_table       = rx8010_id,
 429 };
 430
 431 module_i2c_driver(rx8010_driver);
 432
 433 MODULE_AUTHOR("Akshay Bhat <akshay.bhat@timesys.com>");
 434 MODULE_DESCRIPTION("Epson RX8010SJ RTC driver");
 435 MODULE_LICENSE("GPL v2");