drivers/rtc/rtc-pcf85363.c

   1 /*
   2  * drivers/rtc/rtc-pcf85363.c
   3  *
   4  * Driver for NXP PCF85363 real-time clock.
   5  *
   6  * Copyright (C) 2017 Eric Nelson
   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  * Based loosely on rtc-8583 by Russell King, Wolfram Sang and Juergen Beisert
  13  */
  14 #include <linux/module.h>
  15 #include <linux/i2c.h>
  16 #include <linux/slab.h>
  17 #include <linux/rtc.h>
  18 #include <linux/init.h>
  19 #include <linux/err.h>
  20 #include <linux/errno.h>
  21 #include <linux/bcd.h>
  22 #include <linux/of.h>
  23 #include <linux/of_device.h>
  24 #include <linux/regmap.h>
  25
  26 /*
  27  * Date/Time registers
  28  */
  29 #define DT_100THS       0x00
  30 #define DT_SECS         0x01
  31 #define DT_MINUTES      0x02
  32 #define DT_HOURS        0x03
  33 #define DT_DAYS         0x04
  34 #define DT_WEEKDAYS     0x05
  35 #define DT_MONTHS       0x06
  36 #define DT_YEARS        0x07
  37
  38 /*
  39  * Alarm registers
  40  */
  41 #define DT_SECOND_ALM1  0x08
  42 #define DT_MINUTE_ALM1  0x09
  43 #define DT_HOUR_ALM1    0x0a
  44 #define DT_DAY_ALM1     0x0b
  45 #define DT_MONTH_ALM1   0x0c
  46 #define DT_MINUTE_ALM2  0x0d
  47 #define DT_HOUR_ALM2    0x0e
  48 #define DT_WEEKDAY_ALM2 0x0f
  49 #define DT_ALARM_EN     0x10
  50
  51 /*
  52  * Time stamp registers
  53  */
  54 #define DT_TIMESTAMP1   0x11
  55 #define DT_TIMESTAMP2   0x17
  56 #define DT_TIMESTAMP3   0x1d
  57 #define DT_TS_MODE      0x23
  58
  59 /*
  60  * control registers
  61  */
  62 #define CTRL_OFFSET     0x24
  63 #define CTRL_OSCILLATOR 0x25
  64 #define CTRL_BATTERY    0x26
  65 #define CTRL_PIN_IO     0x27
  66 #define CTRL_FUNCTION   0x28
  67 #define CTRL_INTA_EN    0x29
  68 #define CTRL_INTB_EN    0x2a
  69 #define CTRL_FLAGS      0x2b
  70 #define CTRL_RAMBYTE    0x2c
  71 #define CTRL_WDOG       0x2d
  72 #define CTRL_STOP_EN    0x2e
  73 #define CTRL_RESETS     0x2f
  74 #define CTRL_RAM        0x40
  75
  76 #define ALRM_SEC_A1E    BIT(0)
  77 #define ALRM_MIN_A1E    BIT(1)
  78 #define ALRM_HR_A1E     BIT(2)
  79 #define ALRM_DAY_A1E    BIT(3)
  80 #define ALRM_MON_A1E    BIT(4)
  81 #define ALRM_MIN_A2E    BIT(5)
  82 #define ALRM_HR_A2E     BIT(6)
  83 #define ALRM_DAY_A2E    BIT(7)
  84
  85 #define INT_WDIE        BIT(0)
  86 #define INT_BSIE        BIT(1)
  87 #define INT_TSRIE       BIT(2)
  88 #define INT_A2IE        BIT(3)
  89 #define INT_A1IE        BIT(4)
  90 #define INT_OIE         BIT(5)
  91 #define INT_PIE         BIT(6)
  92 #define INT_ILP         BIT(7)
  93
  94 #define FLAGS_TSR1F     BIT(0)
  95 #define FLAGS_TSR2F     BIT(1)
  96 #define FLAGS_TSR3F     BIT(2)
  97 #define FLAGS_BSF       BIT(3)
  98 #define FLAGS_WDF       BIT(4)
  99 #define FLAGS_A1F       BIT(5)
 100 #define FLAGS_A2F       BIT(6)
 101 #define FLAGS_PIF       BIT(7)
 102
 103 #define PIN_IO_INTAPM   GENMASK(1, 0)
 104 #define PIN_IO_INTA_CLK 0
 105 #define PIN_IO_INTA_BAT 1
 106 #define PIN_IO_INTA_OUT 2
 107 #define PIN_IO_INTA_HIZ 3
 108
 109 #define STOP_EN_STOP    BIT(0)
 110
 111 #define RESET_CPR       0xa4
 112
 113 #define NVRAM_SIZE      0x40
 114
 115 static struct i2c_driver pcf85363_driver;
 116
 117 struct pcf85363 {
 118         struct device           *dev;
 119         struct rtc_device       *rtc;
 120         struct regmap           *regmap;
 121 };
 122
 123 struct pcf85x63_config {
 124         struct regmap_config regmap;
 125         unsigned int num_nvram;
 126 };
 127
 128 static int pcf85363_rtc_read_time(struct device *dev, struct rtc_time *tm)
 129 {
 130         struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
 131         unsigned char buf[DT_YEARS + 1];
 132         int ret, len = sizeof(buf);
 133
 134         /* read the RTC date and time registers all at once */
 135         ret = regmap_bulk_read(pcf85363->regmap, DT_100THS, buf, len);
 136         if (ret) {
 137                 dev_err(dev, "%s: error %d\n", __func__, ret);
 138                 return ret;
 139         }
 140
 141         tm->tm_year = bcd2bin(buf[DT_YEARS]);
 142         /* adjust for 1900 base of rtc_time */
 143         tm->tm_year += 100;
 144
 145         tm->tm_wday = buf[DT_WEEKDAYS] & 7;
 146         buf[DT_SECS] &= 0x7F;
 147         tm->tm_sec = bcd2bin(buf[DT_SECS]);
 148         buf[DT_MINUTES] &= 0x7F;
 149         tm->tm_min = bcd2bin(buf[DT_MINUTES]);
 150         tm->tm_hour = bcd2bin(buf[DT_HOURS]);
 151         tm->tm_mday = bcd2bin(buf[DT_DAYS]);
 152         tm->tm_mon = bcd2bin(buf[DT_MONTHS]) - 1;
 153
 154         return 0;
 155 }
 156
 157 static int pcf85363_rtc_set_time(struct device *dev, struct rtc_time *tm)
 158 {
 159         struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
 160         unsigned char tmp[11];
 161         unsigned char *buf = &tmp[2];
 162         int ret;
 163
 164         tmp[0] = STOP_EN_STOP;
 165         tmp[1] = RESET_CPR;
 166
 167         buf[DT_100THS] = 0;
 168         buf[DT_SECS] = bin2bcd(tm->tm_sec);
 169         buf[DT_MINUTES] = bin2bcd(tm->tm_min);
 170         buf[DT_HOURS] = bin2bcd(tm->tm_hour);
 171         buf[DT_DAYS] = bin2bcd(tm->tm_mday);
 172         buf[DT_WEEKDAYS] = tm->tm_wday;
 173         buf[DT_MONTHS] = bin2bcd(tm->tm_mon + 1);
 174         buf[DT_YEARS] = bin2bcd(tm->tm_year % 100);
 175
 176         ret = regmap_bulk_write(pcf85363->regmap, CTRL_STOP_EN,
 177                                 tmp, sizeof(tmp));
 178         if (ret)
 179                 return ret;
 180
 181         return regmap_write(pcf85363->regmap, CTRL_STOP_EN, 0);
 182 }
 183
 184 static int pcf85363_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 185 {
 186         struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
 187         unsigned char buf[DT_MONTH_ALM1 - DT_SECOND_ALM1 + 1];
 188         unsigned int val;
 189         int ret;
 190
 191         ret = regmap_bulk_read(pcf85363->regmap, DT_SECOND_ALM1, buf,
 192                                sizeof(buf));
 193         if (ret)
 194                 return ret;
 195
 196         alrm->time.tm_sec = bcd2bin(buf[0]);
 197         alrm->time.tm_min = bcd2bin(buf[1]);
 198         alrm->time.tm_hour = bcd2bin(buf[2]);
 199         alrm->time.tm_mday = bcd2bin(buf[3]);
 200         alrm->time.tm_mon = bcd2bin(buf[4]) - 1;
 201
 202         ret = regmap_read(pcf85363->regmap, CTRL_INTA_EN, &val);
 203         if (ret)
 204                 return ret;
 205
 206         alrm->enabled =  !!(val & INT_A1IE);
 207
 208         return 0;
 209 }
 210
 211 static int _pcf85363_rtc_alarm_irq_enable(struct pcf85363 *pcf85363, unsigned
 212                                           int enabled)
 213 {
 214         unsigned int alarm_flags = ALRM_SEC_A1E | ALRM_MIN_A1E | ALRM_HR_A1E |
 215                                    ALRM_DAY_A1E | ALRM_MON_A1E;
 216         int ret;
 217
 218         ret = regmap_update_bits(pcf85363->regmap, DT_ALARM_EN, alarm_flags,
 219                                  enabled ? alarm_flags : 0);
 220         if (ret)
 221                 return ret;
 222
 223         ret = regmap_update_bits(pcf85363->regmap, CTRL_INTA_EN,
 224                                  INT_A1IE, enabled ? INT_A1IE : 0);
 225
 226         if (ret || enabled)
 227                 return ret;
 228
 229         /* clear current flags */
 230         return regmap_update_bits(pcf85363->regmap, CTRL_FLAGS, FLAGS_A1F, 0);
 231 }
 232
 233 static int pcf85363_rtc_alarm_irq_enable(struct device *dev,
 234                                          unsigned int enabled)
 235 {
 236         struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
 237
 238         return _pcf85363_rtc_alarm_irq_enable(pcf85363, enabled);
 239 }
 240
 241 static int pcf85363_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 242 {
 243         struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
 244         unsigned char buf[DT_MONTH_ALM1 - DT_SECOND_ALM1 + 1];
 245         int ret;
 246
 247         buf[0] = bin2bcd(alrm->time.tm_sec);
 248         buf[1] = bin2bcd(alrm->time.tm_min);
 249         buf[2] = bin2bcd(alrm->time.tm_hour);
 250         buf[3] = bin2bcd(alrm->time.tm_mday);
 251         buf[4] = bin2bcd(alrm->time.tm_mon + 1);
 252
 253         /*
 254          * Disable the alarm interrupt before changing the value to avoid
 255          * spurious interrupts
 256          */
 257         ret = _pcf85363_rtc_alarm_irq_enable(pcf85363, 0);
 258         if (ret)
 259                 return ret;
 260
 261         ret = regmap_bulk_write(pcf85363->regmap, DT_SECOND_ALM1, buf,
 262                                 sizeof(buf));
 263         if (ret)
 264                 return ret;
 265
 266         return _pcf85363_rtc_alarm_irq_enable(pcf85363, alrm->enabled);
 267 }
 268
 269 static irqreturn_t pcf85363_rtc_handle_irq(int irq, void *dev_id)
 270 {
 271         struct pcf85363 *pcf85363 = i2c_get_clientdata(dev_id);
 272         unsigned int flags;
 273         int err;
 274
 275         err = regmap_read(pcf85363->regmap, CTRL_FLAGS, &flags);
 276         if (err)
 277                 return IRQ_NONE;
 278
 279         if (flags & FLAGS_A1F) {
 280                 rtc_update_irq(pcf85363->rtc, 1, RTC_IRQF | RTC_AF);
 281                 regmap_update_bits(pcf85363->regmap, CTRL_FLAGS, FLAGS_A1F, 0);
 282                 return IRQ_HANDLED;
 283         }
 284
 285         return IRQ_NONE;
 286 }
 287
 288 static const struct rtc_class_ops rtc_ops = {
 289         .read_time      = pcf85363_rtc_read_time,
 290         .set_time       = pcf85363_rtc_set_time,
 291 };
 292
 293 static const struct rtc_class_ops rtc_ops_alarm = {
 294         .read_time      = pcf85363_rtc_read_time,
 295         .set_time       = pcf85363_rtc_set_time,
 296         .read_alarm     = pcf85363_rtc_read_alarm,
 297         .set_alarm      = pcf85363_rtc_set_alarm,
 298         .alarm_irq_enable = pcf85363_rtc_alarm_irq_enable,
 299 };
 300
 301 static int pcf85363_nvram_read(void *priv, unsigned int offset, void *val,
 302                                size_t bytes)
 303 {
 304         struct pcf85363 *pcf85363 = priv;
 305
 306         return regmap_bulk_read(pcf85363->regmap, CTRL_RAM + offset,
 307                                 val, bytes);
 308 }
 309
 310 static int pcf85363_nvram_write(void *priv, unsigned int offset, void *val,
 311                                 size_t bytes)
 312 {
 313         struct pcf85363 *pcf85363 = priv;
 314
 315         return regmap_bulk_write(pcf85363->regmap, CTRL_RAM + offset,
 316                                  val, bytes);
 317 }
 318
 319 static int pcf85x63_nvram_read(void *priv, unsigned int offset, void *val,
 320                                size_t bytes)
 321 {
 322         struct pcf85363 *pcf85363 = priv;
 323         unsigned int tmp_val;
 324         int ret;
 325
 326         ret = regmap_read(pcf85363->regmap, CTRL_RAMBYTE, &tmp_val);
 327         (*(unsigned char *) val) = (unsigned char) tmp_val;
 328
 329         return ret;
 330 }
 331
 332 static int pcf85x63_nvram_write(void *priv, unsigned int offset, void *val,
 333                                 size_t bytes)
 334 {
 335         struct pcf85363 *pcf85363 = priv;
 336         unsigned char tmp_val;
 337
 338         tmp_val = *((unsigned char *)val);
 339         return regmap_write(pcf85363->regmap, CTRL_RAMBYTE,
 340                                 (unsigned int)tmp_val);
 341 }
 342
 343 static const struct pcf85x63_config pcf_85263_config = {
 344         .regmap = {
 345                 .reg_bits = 8,
 346                 .val_bits = 8,
 347                 .max_register = 0x2f,
 348         },
 349         .num_nvram = 1
 350 };
 351
 352 static const struct pcf85x63_config pcf_85363_config = {
 353         .regmap = {
 354                 .reg_bits = 8,
 355                 .val_bits = 8,
 356                 .max_register = 0x7f,
 357         },
 358         .num_nvram = 2
 359 };
 360
 361 static int pcf85363_probe(struct i2c_client *client,
 362                           const struct i2c_device_id *id)
 363 {
 364         struct pcf85363 *pcf85363;
 365         const struct pcf85x63_config *config = &pcf_85363_config;
 366         const void *data = of_device_get_match_data(&client->dev);
 367         static struct nvmem_config nvmem_cfg[] = {
 368                 {
 369                         .name = "pcf85x63-",
 370                         .word_size = 1,
 371                         .stride = 1,
 372                         .size = 1,
 373                         .reg_read = pcf85x63_nvram_read,
 374                         .reg_write = pcf85x63_nvram_write,
 375                 }, {
 376                         .name = "pcf85363-",
 377                         .word_size = 1,
 378                         .stride = 1,
 379                         .size = NVRAM_SIZE,
 380                         .reg_read = pcf85363_nvram_read,
 381                         .reg_write = pcf85363_nvram_write,
 382                 },
 383         };
 384         int ret, i;
 385
 386         if (data)
 387                 config = data;
 388
 389         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
 390                 return -ENODEV;
 391
 392         pcf85363 = devm_kzalloc(&client->dev, sizeof(struct pcf85363),
 393                                 GFP_KERNEL);
 394         if (!pcf85363)
 395                 return -ENOMEM;
 396
 397         pcf85363->regmap = devm_regmap_init_i2c(client, &config->regmap);
 398         if (IS_ERR(pcf85363->regmap)) {
 399                 dev_err(&client->dev, "regmap allocation failed\n");
 400                 return PTR_ERR(pcf85363->regmap);
 401         }
 402
 403         pcf85363->dev = &client->dev;
 404         i2c_set_clientdata(client, pcf85363);
 405
 406         pcf85363->rtc = devm_rtc_allocate_device(pcf85363->dev);
 407         if (IS_ERR(pcf85363->rtc))
 408                 return PTR_ERR(pcf85363->rtc);
 409
 410         pcf85363->rtc->ops = &rtc_ops;
 411
 412         if (client->irq > 0) {
 413                 regmap_write(pcf85363->regmap, CTRL_FLAGS, 0);
 414                 regmap_update_bits(pcf85363->regmap, CTRL_PIN_IO,
 415                                    PIN_IO_INTA_OUT, PIN_IO_INTAPM);
 416                 ret = devm_request_threaded_irq(pcf85363->dev, client->irq,
 417                                                 NULL, pcf85363_rtc_handle_irq,
 418                                                 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 419                                                 "pcf85363", client);
 420                 if (ret)
 421                         dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
 422                 else
 423                         pcf85363->rtc->ops = &rtc_ops_alarm;
 424         }
 425
 426         ret = rtc_register_device(pcf85363->rtc);
 427
 428         for (i = 0; i < config->num_nvram; i++) {
 429                 nvmem_cfg[i].priv = pcf85363;
 430                 rtc_nvmem_register(pcf85363->rtc, &nvmem_cfg[i]);
 431         }
 432
 433         return ret;
 434 }
 435
 436 static const struct of_device_id dev_ids[] = {
 437         { .compatible = "nxp,pcf85263", .data = &pcf_85263_config },
 438         { .compatible = "nxp,pcf85363", .data = &pcf_85363_config },
 439         { /* sentinel */ }
 440 };
 441 MODULE_DEVICE_TABLE(of, dev_ids);
 442
 443 static struct i2c_driver pcf85363_driver = {
 444         .driver = {
 445                 .name   = "pcf85363",
 446                 .of_match_table = of_match_ptr(dev_ids),
 447         },
 448         .probe  = pcf85363_probe,
 449 };
 450
 451 module_i2c_driver(pcf85363_driver);
 452
 453 MODULE_AUTHOR("Eric Nelson");
 454 MODULE_DESCRIPTION("pcf85263/pcf85363 I2C RTC driver");
 455 MODULE_LICENSE("GPL");