drivers/rtc/rtc-pcf85363.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * drivers/rtc/rtc-pcf85363.c
   4  *
   5  * Driver for NXP PCF85363 real-time clock.
   6  *
   7  * Copyright (C) 2017 Eric Nelson
   8  */
   9 #include <linux/module.h>
  10 #include <linux/i2c.h>
  11 #include <linux/slab.h>
  12 #include <linux/rtc.h>
  13 #include <linux/init.h>
  14 #include <linux/err.h>
  15 #include <linux/errno.h>
  16 #include <linux/bcd.h>
  17 #include <linux/of.h>
  18 #include <linux/of_device.h>
  19 #include <linux/regmap.h>
  20
  21 /*
  22  * Date/Time registers
  23  */
  24 #define DT_100THS       0x00
  25 #define DT_SECS         0x01
  26 #define DT_MINUTES      0x02
  27 #define DT_HOURS        0x03
  28 #define DT_DAYS         0x04
  29 #define DT_WEEKDAYS     0x05
  30 #define DT_MONTHS       0x06
  31 #define DT_YEARS        0x07
  32
  33 /*
  34  * Alarm registers
  35  */
  36 #define DT_SECOND_ALM1  0x08
  37 #define DT_MINUTE_ALM1  0x09
  38 #define DT_HOUR_ALM1    0x0a
  39 #define DT_DAY_ALM1     0x0b
  40 #define DT_MONTH_ALM1   0x0c
  41 #define DT_MINUTE_ALM2  0x0d
  42 #define DT_HOUR_ALM2    0x0e
  43 #define DT_WEEKDAY_ALM2 0x0f
  44 #define DT_ALARM_EN     0x10
  45
  46 /*
  47  * Time stamp registers
  48  */
  49 #define DT_TIMESTAMP1   0x11
  50 #define DT_TIMESTAMP2   0x17
  51 #define DT_TIMESTAMP3   0x1d
  52 #define DT_TS_MODE      0x23
  53
  54 /*
  55  * control registers
  56  */
  57 #define CTRL_OFFSET     0x24
  58 #define CTRL_OSCILLATOR 0x25
  59 #define CTRL_BATTERY    0x26
  60 #define CTRL_PIN_IO     0x27
  61 #define CTRL_FUNCTION   0x28
  62 #define CTRL_INTA_EN    0x29
  63 #define CTRL_INTB_EN    0x2a
  64 #define CTRL_FLAGS      0x2b
  65 #define CTRL_RAMBYTE    0x2c
  66 #define CTRL_WDOG       0x2d
  67 #define CTRL_STOP_EN    0x2e
  68 #define CTRL_RESETS     0x2f
  69 #define CTRL_RAM        0x40
  70
  71 #define ALRM_SEC_A1E    BIT(0)
  72 #define ALRM_MIN_A1E    BIT(1)
  73 #define ALRM_HR_A1E     BIT(2)
  74 #define ALRM_DAY_A1E    BIT(3)
  75 #define ALRM_MON_A1E    BIT(4)
  76 #define ALRM_MIN_A2E    BIT(5)
  77 #define ALRM_HR_A2E     BIT(6)
  78 #define ALRM_DAY_A2E    BIT(7)
  79
  80 #define INT_WDIE        BIT(0)
  81 #define INT_BSIE        BIT(1)
  82 #define INT_TSRIE       BIT(2)
  83 #define INT_A2IE        BIT(3)
  84 #define INT_A1IE        BIT(4)
  85 #define INT_OIE         BIT(5)
  86 #define INT_PIE         BIT(6)
  87 #define INT_ILP         BIT(7)
  88
  89 #define FLAGS_TSR1F     BIT(0)
  90 #define FLAGS_TSR2F     BIT(1)
  91 #define FLAGS_TSR3F     BIT(2)
  92 #define FLAGS_BSF       BIT(3)
  93 #define FLAGS_WDF       BIT(4)
  94 #define FLAGS_A1F       BIT(5)
  95 #define FLAGS_A2F       BIT(6)
  96 #define FLAGS_PIF       BIT(7)
  97
  98 #define PIN_IO_INTAPM   GENMASK(1, 0)
  99 #define PIN_IO_INTA_CLK 0
 100 #define PIN_IO_INTA_BAT 1
 101 #define PIN_IO_INTA_OUT 2
 102 #define PIN_IO_INTA_HIZ 3
 103
 104 #define STOP_EN_STOP    BIT(0)
 105
 106 #define RESET_CPR       0xa4
 107
 108 #define NVRAM_SIZE      0x40
 109
 110 struct pcf85363 {
 111         struct rtc_device       *rtc;
 112         struct regmap           *regmap;
 113 };
 114
 115 struct pcf85x63_config {
 116         struct regmap_config regmap;
 117         unsigned int num_nvram;
 118 };
 119
 120 static int pcf85363_rtc_read_time(struct device *dev, struct rtc_time *tm)
 121 {
 122         struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
 123         unsigned char buf[DT_YEARS + 1];
 124         int ret, len = sizeof(buf);
 125
 126         /* read the RTC date and time registers all at once */
 127         ret = regmap_bulk_read(pcf85363->regmap, DT_100THS, buf, len);
 128         if (ret) {
 129                 dev_err(dev, "%s: error %d\n", __func__, ret);
 130                 return ret;
 131         }
 132
 133         tm->tm_year = bcd2bin(buf[DT_YEARS]);
 134         /* adjust for 1900 base of rtc_time */
 135         tm->tm_year += 100;
 136
 137         tm->tm_wday = buf[DT_WEEKDAYS] & 7;
 138         buf[DT_SECS] &= 0x7F;
 139         tm->tm_sec = bcd2bin(buf[DT_SECS]);
 140         buf[DT_MINUTES] &= 0x7F;
 141         tm->tm_min = bcd2bin(buf[DT_MINUTES]);
 142         tm->tm_hour = bcd2bin(buf[DT_HOURS]);
 143         tm->tm_mday = bcd2bin(buf[DT_DAYS]);
 144         tm->tm_mon = bcd2bin(buf[DT_MONTHS]) - 1;
 145
 146         return 0;
 147 }
 148
 149 static int pcf85363_rtc_set_time(struct device *dev, struct rtc_time *tm)
 150 {
 151         struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
 152         unsigned char tmp[11];
 153         unsigned char *buf = &tmp[2];
 154         int ret;
 155
 156         tmp[0] = STOP_EN_STOP;
 157         tmp[1] = RESET_CPR;
 158
 159         buf[DT_100THS] = 0;
 160         buf[DT_SECS] = bin2bcd(tm->tm_sec);
 161         buf[DT_MINUTES] = bin2bcd(tm->tm_min);
 162         buf[DT_HOURS] = bin2bcd(tm->tm_hour);
 163         buf[DT_DAYS] = bin2bcd(tm->tm_mday);
 164         buf[DT_WEEKDAYS] = tm->tm_wday;
 165         buf[DT_MONTHS] = bin2bcd(tm->tm_mon + 1);
 166         buf[DT_YEARS] = bin2bcd(tm->tm_year % 100);
 167
 168         ret = regmap_bulk_write(pcf85363->regmap, CTRL_STOP_EN,
 169                                 tmp, 2);
 170         if (ret)
 171                 return ret;
 172
 173         ret = regmap_bulk_write(pcf85363->regmap, DT_100THS,
 174                                 buf, sizeof(tmp) - 2);
 175         if (ret)
 176                 return ret;
 177
 178         return regmap_write(pcf85363->regmap, CTRL_STOP_EN, 0);
 179 }
 180
 181 static int pcf85363_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 182 {
 183         struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
 184         unsigned char buf[DT_MONTH_ALM1 - DT_SECOND_ALM1 + 1];
 185         unsigned int val;
 186         int ret;
 187
 188         ret = regmap_bulk_read(pcf85363->regmap, DT_SECOND_ALM1, buf,
 189                                sizeof(buf));
 190         if (ret)
 191                 return ret;
 192
 193         alrm->time.tm_sec = bcd2bin(buf[0]);
 194         alrm->time.tm_min = bcd2bin(buf[1]);
 195         alrm->time.tm_hour = bcd2bin(buf[2]);
 196         alrm->time.tm_mday = bcd2bin(buf[3]);
 197         alrm->time.tm_mon = bcd2bin(buf[4]) - 1;
 198
 199         ret = regmap_read(pcf85363->regmap, CTRL_INTA_EN, &val);
 200         if (ret)
 201                 return ret;
 202
 203         alrm->enabled =  !!(val & INT_A1IE);
 204
 205         return 0;
 206 }
 207
 208 static int _pcf85363_rtc_alarm_irq_enable(struct pcf85363 *pcf85363, unsigned
 209                                           int enabled)
 210 {
 211         unsigned int alarm_flags = ALRM_SEC_A1E | ALRM_MIN_A1E | ALRM_HR_A1E |
 212                                    ALRM_DAY_A1E | ALRM_MON_A1E;
 213         int ret;
 214
 215         ret = regmap_update_bits(pcf85363->regmap, DT_ALARM_EN, alarm_flags,
 216                                  enabled ? alarm_flags : 0);
 217         if (ret)
 218                 return ret;
 219
 220         ret = regmap_update_bits(pcf85363->regmap, CTRL_INTA_EN,
 221                                  INT_A1IE, enabled ? INT_A1IE : 0);
 222
 223         if (ret || enabled)
 224                 return ret;
 225
 226         /* clear current flags */
 227         return regmap_update_bits(pcf85363->regmap, CTRL_FLAGS, FLAGS_A1F, 0);
 228 }
 229
 230 static int pcf85363_rtc_alarm_irq_enable(struct device *dev,
 231                                          unsigned int enabled)
 232 {
 233         struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
 234
 235         return _pcf85363_rtc_alarm_irq_enable(pcf85363, enabled);
 236 }
 237
 238 static int pcf85363_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 239 {
 240         struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
 241         unsigned char buf[DT_MONTH_ALM1 - DT_SECOND_ALM1 + 1];
 242         int ret;
 243
 244         buf[0] = bin2bcd(alrm->time.tm_sec);
 245         buf[1] = bin2bcd(alrm->time.tm_min);
 246         buf[2] = bin2bcd(alrm->time.tm_hour);
 247         buf[3] = bin2bcd(alrm->time.tm_mday);
 248         buf[4] = bin2bcd(alrm->time.tm_mon + 1);
 249
 250         /*
 251          * Disable the alarm interrupt before changing the value to avoid
 252          * spurious interrupts
 253          */
 254         ret = _pcf85363_rtc_alarm_irq_enable(pcf85363, 0);
 255         if (ret)
 256                 return ret;
 257
 258         ret = regmap_bulk_write(pcf85363->regmap, DT_SECOND_ALM1, buf,
 259                                 sizeof(buf));
 260         if (ret)
 261                 return ret;
 262
 263         return _pcf85363_rtc_alarm_irq_enable(pcf85363, alrm->enabled);
 264 }
 265
 266 static irqreturn_t pcf85363_rtc_handle_irq(int irq, void *dev_id)
 267 {
 268         struct pcf85363 *pcf85363 = i2c_get_clientdata(dev_id);
 269         unsigned int flags;
 270         int err;
 271
 272         err = regmap_read(pcf85363->regmap, CTRL_FLAGS, &flags);
 273         if (err)
 274                 return IRQ_NONE;
 275
 276         if (flags & FLAGS_A1F) {
 277                 rtc_update_irq(pcf85363->rtc, 1, RTC_IRQF | RTC_AF);
 278                 regmap_update_bits(pcf85363->regmap, CTRL_FLAGS, FLAGS_A1F, 0);
 279                 return IRQ_HANDLED;
 280         }
 281
 282         return IRQ_NONE;
 283 }
 284
 285 static const struct rtc_class_ops rtc_ops = {
 286         .read_time      = pcf85363_rtc_read_time,
 287         .set_time       = pcf85363_rtc_set_time,
 288         .read_alarm     = pcf85363_rtc_read_alarm,
 289         .set_alarm      = pcf85363_rtc_set_alarm,
 290         .alarm_irq_enable = pcf85363_rtc_alarm_irq_enable,
 291 };
 292
 293 static int pcf85363_nvram_read(void *priv, unsigned int offset, void *val,
 294                                size_t bytes)
 295 {
 296         struct pcf85363 *pcf85363 = priv;
 297
 298         return regmap_bulk_read(pcf85363->regmap, CTRL_RAM + offset,
 299                                 val, bytes);
 300 }
 301
 302 static int pcf85363_nvram_write(void *priv, unsigned int offset, void *val,
 303                                 size_t bytes)
 304 {
 305         struct pcf85363 *pcf85363 = priv;
 306
 307         return regmap_bulk_write(pcf85363->regmap, CTRL_RAM + offset,
 308                                  val, bytes);
 309 }
 310
 311 static int pcf85x63_nvram_read(void *priv, unsigned int offset, void *val,
 312                                size_t bytes)
 313 {
 314         struct pcf85363 *pcf85363 = priv;
 315         unsigned int tmp_val;
 316         int ret;
 317
 318         ret = regmap_read(pcf85363->regmap, CTRL_RAMBYTE, &tmp_val);
 319         (*(unsigned char *) val) = (unsigned char) tmp_val;
 320
 321         return ret;
 322 }
 323
 324 static int pcf85x63_nvram_write(void *priv, unsigned int offset, void *val,
 325                                 size_t bytes)
 326 {
 327         struct pcf85363 *pcf85363 = priv;
 328         unsigned char tmp_val;
 329
 330         tmp_val = *((unsigned char *)val);
 331         return regmap_write(pcf85363->regmap, CTRL_RAMBYTE,
 332                                 (unsigned int)tmp_val);
 333 }
 334
 335 static const struct pcf85x63_config pcf_85263_config = {
 336         .regmap = {
 337                 .reg_bits = 8,
 338                 .val_bits = 8,
 339                 .max_register = 0x2f,
 340         },
 341         .num_nvram = 1
 342 };
 343
 344 static const struct pcf85x63_config pcf_85363_config = {
 345         .regmap = {
 346                 .reg_bits = 8,
 347                 .val_bits = 8,
 348                 .max_register = 0x7f,
 349         },
 350         .num_nvram = 2
 351 };
 352
 353 static int pcf85363_probe(struct i2c_client *client,
 354                           const struct i2c_device_id *id)
 355 {
 356         struct pcf85363 *pcf85363;
 357         const struct pcf85x63_config *config = &pcf_85363_config;
 358         const void *data = of_device_get_match_data(&client->dev);
 359         static struct nvmem_config nvmem_cfg[] = {
 360                 {
 361                         .name = "pcf85x63-",
 362                         .word_size = 1,
 363                         .stride = 1,
 364                         .size = 1,
 365                         .reg_read = pcf85x63_nvram_read,
 366                         .reg_write = pcf85x63_nvram_write,
 367                 }, {
 368                         .name = "pcf85363-",
 369                         .word_size = 1,
 370                         .stride = 1,
 371                         .size = NVRAM_SIZE,
 372                         .reg_read = pcf85363_nvram_read,
 373                         .reg_write = pcf85363_nvram_write,
 374                 },
 375         };
 376         int ret, i;
 377
 378         if (data)
 379                 config = data;
 380
 381         pcf85363 = devm_kzalloc(&client->dev, sizeof(struct pcf85363),
 382                                 GFP_KERNEL);
 383         if (!pcf85363)
 384                 return -ENOMEM;
 385
 386         pcf85363->regmap = devm_regmap_init_i2c(client, &config->regmap);
 387         if (IS_ERR(pcf85363->regmap)) {
 388                 dev_err(&client->dev, "regmap allocation failed\n");
 389                 return PTR_ERR(pcf85363->regmap);
 390         }
 391
 392         i2c_set_clientdata(client, pcf85363);
 393
 394         pcf85363->rtc = devm_rtc_allocate_device(&client->dev);
 395         if (IS_ERR(pcf85363->rtc))
 396                 return PTR_ERR(pcf85363->rtc);
 397
 398         pcf85363->rtc->ops = &rtc_ops;
 399         pcf85363->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 400         pcf85363->rtc->range_max = RTC_TIMESTAMP_END_2099;
 401         clear_bit(RTC_FEATURE_ALARM, pcf85363->rtc->features);
 402
 403         if (client->irq > 0) {
 404                 regmap_write(pcf85363->regmap, CTRL_FLAGS, 0);
 405                 regmap_update_bits(pcf85363->regmap, CTRL_PIN_IO,
 406                                    PIN_IO_INTA_OUT, PIN_IO_INTAPM);
 407                 ret = devm_request_threaded_irq(&client->dev, client->irq,
 408                                                 NULL, pcf85363_rtc_handle_irq,
 409                                                 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 410                                                 "pcf85363", client);
 411                 if (ret)
 412                         dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
 413                 else
 414                         set_bit(RTC_FEATURE_ALARM, pcf85363->rtc->features);
 415         }
 416
 417         ret = devm_rtc_register_device(pcf85363->rtc);
 418
 419         for (i = 0; i < config->num_nvram; i++) {
 420                 nvmem_cfg[i].priv = pcf85363;
 421                 devm_rtc_nvmem_register(pcf85363->rtc, &nvmem_cfg[i]);
 422         }
 423
 424         return ret;
 425 }
 426
 427 static const __maybe_unused struct of_device_id dev_ids[] = {
 428         { .compatible = "nxp,pcf85263", .data = &pcf_85263_config },
 429         { .compatible = "nxp,pcf85363", .data = &pcf_85363_config },
 430         { /* sentinel */ }
 431 };
 432 MODULE_DEVICE_TABLE(of, dev_ids);
 433
 434 static struct i2c_driver pcf85363_driver = {
 435         .driver = {
 436                 .name   = "pcf85363",
 437                 .of_match_table = of_match_ptr(dev_ids),
 438         },
 439         .probe  = pcf85363_probe,
 440 };
 441
 442 module_i2c_driver(pcf85363_driver);
 443
 444 MODULE_AUTHOR("Eric Nelson");
 445 MODULE_DESCRIPTION("pcf85263/pcf85363 I2C RTC driver");
 446 MODULE_LICENSE("GPL");