linux/drivers/rtc/rtc-pcf85363.c
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   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
 110struct pcf85363 {
 111        struct rtc_device       *rtc;
 112        struct regmap           *regmap;
 113};
 114
 115struct pcf85x63_config {
 116        struct regmap_config regmap;
 117        unsigned int num_nvram;
 118};
 119
 120static 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
 149static 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
 181static 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
 208static 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
 230static 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
 238static 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
 266static 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
 285static const struct rtc_class_ops rtc_ops = {
 286        .read_time      = pcf85363_rtc_read_time,
 287        .set_time       = pcf85363_rtc_set_time,
 288};
 289
 290static const struct rtc_class_ops rtc_ops_alarm = {
 291        .read_time      = pcf85363_rtc_read_time,
 292        .set_time       = pcf85363_rtc_set_time,
 293        .read_alarm     = pcf85363_rtc_read_alarm,
 294        .set_alarm      = pcf85363_rtc_set_alarm,
 295        .alarm_irq_enable = pcf85363_rtc_alarm_irq_enable,
 296};
 297
 298static int pcf85363_nvram_read(void *priv, unsigned int offset, void *val,
 299                               size_t bytes)
 300{
 301        struct pcf85363 *pcf85363 = priv;
 302
 303        return regmap_bulk_read(pcf85363->regmap, CTRL_RAM + offset,
 304                                val, bytes);
 305}
 306
 307static int pcf85363_nvram_write(void *priv, unsigned int offset, void *val,
 308                                size_t bytes)
 309{
 310        struct pcf85363 *pcf85363 = priv;
 311
 312        return regmap_bulk_write(pcf85363->regmap, CTRL_RAM + offset,
 313                                 val, bytes);
 314}
 315
 316static int pcf85x63_nvram_read(void *priv, unsigned int offset, void *val,
 317                               size_t bytes)
 318{
 319        struct pcf85363 *pcf85363 = priv;
 320        unsigned int tmp_val;
 321        int ret;
 322
 323        ret = regmap_read(pcf85363->regmap, CTRL_RAMBYTE, &tmp_val);
 324        (*(unsigned char *) val) = (unsigned char) tmp_val;
 325
 326        return ret;
 327}
 328
 329static int pcf85x63_nvram_write(void *priv, unsigned int offset, void *val,
 330                                size_t bytes)
 331{
 332        struct pcf85363 *pcf85363 = priv;
 333        unsigned char tmp_val;
 334
 335        tmp_val = *((unsigned char *)val);
 336        return regmap_write(pcf85363->regmap, CTRL_RAMBYTE,
 337                                (unsigned int)tmp_val);
 338}
 339
 340static const struct pcf85x63_config pcf_85263_config = {
 341        .regmap = {
 342                .reg_bits = 8,
 343                .val_bits = 8,
 344                .max_register = 0x2f,
 345        },
 346        .num_nvram = 1
 347};
 348
 349static const struct pcf85x63_config pcf_85363_config = {
 350        .regmap = {
 351                .reg_bits = 8,
 352                .val_bits = 8,
 353                .max_register = 0x7f,
 354        },
 355        .num_nvram = 2
 356};
 357
 358static int pcf85363_probe(struct i2c_client *client,
 359                          const struct i2c_device_id *id)
 360{
 361        struct pcf85363 *pcf85363;
 362        const struct pcf85x63_config *config = &pcf_85363_config;
 363        const void *data = of_device_get_match_data(&client->dev);
 364        static struct nvmem_config nvmem_cfg[] = {
 365                {
 366                        .name = "pcf85x63-",
 367                        .word_size = 1,
 368                        .stride = 1,
 369                        .size = 1,
 370                        .reg_read = pcf85x63_nvram_read,
 371                        .reg_write = pcf85x63_nvram_write,
 372                }, {
 373                        .name = "pcf85363-",
 374                        .word_size = 1,
 375                        .stride = 1,
 376                        .size = NVRAM_SIZE,
 377                        .reg_read = pcf85363_nvram_read,
 378                        .reg_write = pcf85363_nvram_write,
 379                },
 380        };
 381        int ret, i;
 382
 383        if (data)
 384                config = data;
 385
 386        pcf85363 = devm_kzalloc(&client->dev, sizeof(struct pcf85363),
 387                                GFP_KERNEL);
 388        if (!pcf85363)
 389                return -ENOMEM;
 390
 391        pcf85363->regmap = devm_regmap_init_i2c(client, &config->regmap);
 392        if (IS_ERR(pcf85363->regmap)) {
 393                dev_err(&client->dev, "regmap allocation failed\n");
 394                return PTR_ERR(pcf85363->regmap);
 395        }
 396
 397        i2c_set_clientdata(client, pcf85363);
 398
 399        pcf85363->rtc = devm_rtc_allocate_device(&client->dev);
 400        if (IS_ERR(pcf85363->rtc))
 401                return PTR_ERR(pcf85363->rtc);
 402
 403        pcf85363->rtc->ops = &rtc_ops;
 404        pcf85363->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 405        pcf85363->rtc->range_max = RTC_TIMESTAMP_END_2099;
 406
 407        if (client->irq > 0) {
 408                regmap_write(pcf85363->regmap, CTRL_FLAGS, 0);
 409                regmap_update_bits(pcf85363->regmap, CTRL_PIN_IO,
 410                                   PIN_IO_INTA_OUT, PIN_IO_INTAPM);
 411                ret = devm_request_threaded_irq(&client->dev, client->irq,
 412                                                NULL, pcf85363_rtc_handle_irq,
 413                                                IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 414                                                "pcf85363", client);
 415                if (ret)
 416                        dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
 417                else
 418                        pcf85363->rtc->ops = &rtc_ops_alarm;
 419        }
 420
 421        ret = rtc_register_device(pcf85363->rtc);
 422
 423        for (i = 0; i < config->num_nvram; i++) {
 424                nvmem_cfg[i].priv = pcf85363;
 425                rtc_nvmem_register(pcf85363->rtc, &nvmem_cfg[i]);
 426        }
 427
 428        return ret;
 429}
 430
 431static const struct of_device_id dev_ids[] = {
 432        { .compatible = "nxp,pcf85263", .data = &pcf_85263_config },
 433        { .compatible = "nxp,pcf85363", .data = &pcf_85363_config },
 434        { /* sentinel */ }
 435};
 436MODULE_DEVICE_TABLE(of, dev_ids);
 437
 438static struct i2c_driver pcf85363_driver = {
 439        .driver = {
 440                .name   = "pcf85363",
 441                .of_match_table = of_match_ptr(dev_ids),
 442        },
 443        .probe  = pcf85363_probe,
 444};
 445
 446module_i2c_driver(pcf85363_driver);
 447
 448MODULE_AUTHOR("Eric Nelson");
 449MODULE_DESCRIPTION("pcf85263/pcf85363 I2C RTC driver");
 450MODULE_LICENSE("GPL");
 451