drivers/rtc/rtc-pcf2127.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * An I2C and SPI driver for the NXP PCF2127/29 RTC
   4  * Copyright 2013 Til-Technologies
   5  *
   6  * Author: Renaud Cerrato <r.cerrato@til-technologies.fr>
   7  *
   8  * Watchdog and tamper functions
   9  * Author: Bruno Thomsen <bruno.thomsen@gmail.com>
  10  *
  11  * based on the other drivers in this same directory.
  12  *
  13  * Datasheet: http://cache.nxp.com/documents/data_sheet/PCF2127.pdf
  14  */
  15
  16 #include <linux/i2c.h>
  17 #include <linux/spi/spi.h>
  18 #include <linux/bcd.h>
  19 #include <linux/rtc.h>
  20 #include <linux/slab.h>
  21 #include <linux/module.h>
  22 #include <linux/of.h>
  23 #include <linux/regmap.h>
  24 #include <linux/watchdog.h>
  25
  26 /* Control register 1 */
  27 #define PCF2127_REG_CTRL1               0x00
  28 #define PCF2127_BIT_CTRL1_TSF1                  BIT(4)
  29 /* Control register 2 */
  30 #define PCF2127_REG_CTRL2               0x01
  31 #define PCF2127_BIT_CTRL2_TSIE                  BIT(2)
  32 #define PCF2127_BIT_CTRL2_TSF2                  BIT(5)
  33 /* Control register 3 */
  34 #define PCF2127_REG_CTRL3               0x02
  35 #define PCF2127_BIT_CTRL3_BLIE                  BIT(0)
  36 #define PCF2127_BIT_CTRL3_BIE                   BIT(1)
  37 #define PCF2127_BIT_CTRL3_BLF                   BIT(2)
  38 #define PCF2127_BIT_CTRL3_BF                    BIT(3)
  39 #define PCF2127_BIT_CTRL3_BTSE                  BIT(4)
  40 /* Time and date registers */
  41 #define PCF2127_REG_SC                  0x03
  42 #define PCF2127_BIT_SC_OSF                      BIT(7)
  43 #define PCF2127_REG_MN                  0x04
  44 #define PCF2127_REG_HR                  0x05
  45 #define PCF2127_REG_DM                  0x06
  46 #define PCF2127_REG_DW                  0x07
  47 #define PCF2127_REG_MO                  0x08
  48 #define PCF2127_REG_YR                  0x09
  49 /* Watchdog registers */
  50 #define PCF2127_REG_WD_CTL              0x10
  51 #define PCF2127_BIT_WD_CTL_TF0                  BIT(0)
  52 #define PCF2127_BIT_WD_CTL_TF1                  BIT(1)
  53 #define PCF2127_BIT_WD_CTL_CD0                  BIT(6)
  54 #define PCF2127_BIT_WD_CTL_CD1                  BIT(7)
  55 #define PCF2127_REG_WD_VAL              0x11
  56 /* Tamper timestamp registers */
  57 #define PCF2127_REG_TS_CTRL             0x12
  58 #define PCF2127_BIT_TS_CTRL_TSOFF               BIT(6)
  59 #define PCF2127_BIT_TS_CTRL_TSM                 BIT(7)
  60 #define PCF2127_REG_TS_SC               0x13
  61 #define PCF2127_REG_TS_MN               0x14
  62 #define PCF2127_REG_TS_HR               0x15
  63 #define PCF2127_REG_TS_DM               0x16
  64 #define PCF2127_REG_TS_MO               0x17
  65 #define PCF2127_REG_TS_YR               0x18
  66 /*
  67  * RAM registers
  68  * PCF2127 has 512 bytes general-purpose static RAM (SRAM) that is
  69  * battery backed and can survive a power outage.
  70  * PCF2129 doesn't have this feature.
  71  */
  72 #define PCF2127_REG_RAM_ADDR_MSB        0x1A
  73 #define PCF2127_REG_RAM_WRT_CMD         0x1C
  74 #define PCF2127_REG_RAM_RD_CMD          0x1D
  75
  76 /* Watchdog timer value constants */
  77 #define PCF2127_WD_VAL_STOP             0
  78 #define PCF2127_WD_VAL_MIN              2
  79 #define PCF2127_WD_VAL_MAX              255
  80 #define PCF2127_WD_VAL_DEFAULT          60
  81
  82 struct pcf2127 {
  83         struct rtc_device *rtc;
  84         struct watchdog_device wdd;
  85         struct regmap *regmap;
  86 };
  87
  88 /*
  89  * In the routines that deal directly with the pcf2127 hardware, we use
  90  * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
  91  */
  92 static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm)
  93 {
  94         struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
  95         unsigned char buf[10];
  96         int ret;
  97
  98         /*
  99          * Avoid reading CTRL2 register as it causes WD_VAL register
 100          * value to reset to 0 which means watchdog is stopped.
 101          */
 102         ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_CTRL3,
 103                                (buf + PCF2127_REG_CTRL3),
 104                                ARRAY_SIZE(buf) - PCF2127_REG_CTRL3);
 105         if (ret) {
 106                 dev_err(dev, "%s: read error\n", __func__);
 107                 return ret;
 108         }
 109
 110         if (buf[PCF2127_REG_CTRL3] & PCF2127_BIT_CTRL3_BLF)
 111                 dev_info(dev,
 112                         "low voltage detected, check/replace RTC battery.\n");
 113
 114         /* Clock integrity is not guaranteed when OSF flag is set. */
 115         if (buf[PCF2127_REG_SC] & PCF2127_BIT_SC_OSF) {
 116                 /*
 117                  * no need clear the flag here,
 118                  * it will be cleared once the new date is saved
 119                  */
 120                 dev_warn(dev,
 121                          "oscillator stop detected, date/time is not reliable\n");
 122                 return -EINVAL;
 123         }
 124
 125         dev_dbg(dev,
 126                 "%s: raw data is cr3=%02x, sec=%02x, min=%02x, hr=%02x, "
 127                 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
 128                 __func__, buf[PCF2127_REG_CTRL3], buf[PCF2127_REG_SC],
 129                 buf[PCF2127_REG_MN], buf[PCF2127_REG_HR],
 130                 buf[PCF2127_REG_DM], buf[PCF2127_REG_DW],
 131                 buf[PCF2127_REG_MO], buf[PCF2127_REG_YR]);
 132
 133         tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F);
 134         tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F);
 135         tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F); /* rtc hr 0-23 */
 136         tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F);
 137         tm->tm_wday = buf[PCF2127_REG_DW] & 0x07;
 138         tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
 139         tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]);
 140         tm->tm_year += 100;
 141
 142         dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
 143                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 144                 __func__,
 145                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 146                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 147
 148         return 0;
 149 }
 150
 151 static int pcf2127_rtc_set_time(struct device *dev, struct rtc_time *tm)
 152 {
 153         struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
 154         unsigned char buf[7];
 155         int i = 0, err;
 156
 157         dev_dbg(dev, "%s: secs=%d, mins=%d, hours=%d, "
 158                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 159                 __func__,
 160                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 161                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 162
 163         /* hours, minutes and seconds */
 164         buf[i++] = bin2bcd(tm->tm_sec); /* this will also clear OSF flag */
 165         buf[i++] = bin2bcd(tm->tm_min);
 166         buf[i++] = bin2bcd(tm->tm_hour);
 167         buf[i++] = bin2bcd(tm->tm_mday);
 168         buf[i++] = tm->tm_wday & 0x07;
 169
 170         /* month, 1 - 12 */
 171         buf[i++] = bin2bcd(tm->tm_mon + 1);
 172
 173         /* year */
 174         buf[i++] = bin2bcd(tm->tm_year - 100);
 175
 176         /* write register's data */
 177         err = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_SC, buf, i);
 178         if (err) {
 179                 dev_err(dev,
 180                         "%s: err=%d", __func__, err);
 181                 return err;
 182         }
 183
 184         return 0;
 185 }
 186
 187 static int pcf2127_rtc_ioctl(struct device *dev,
 188                                 unsigned int cmd, unsigned long arg)
 189 {
 190         struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
 191         int val, touser = 0;
 192         int ret;
 193
 194         switch (cmd) {
 195         case RTC_VL_READ:
 196                 ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL3, &val);
 197                 if (ret)
 198                         return ret;
 199
 200                 if (val & PCF2127_BIT_CTRL3_BLF)
 201                         touser |= RTC_VL_BACKUP_LOW;
 202
 203                 if (val & PCF2127_BIT_CTRL3_BF)
 204                         touser |= RTC_VL_BACKUP_SWITCH;
 205
 206                 return put_user(touser, (unsigned int __user *)arg);
 207
 208         case RTC_VL_CLR:
 209                 return regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL3,
 210                                           PCF2127_BIT_CTRL3_BF, 0);
 211
 212         default:
 213                 return -ENOIOCTLCMD;
 214         }
 215 }
 216
 217 static const struct rtc_class_ops pcf2127_rtc_ops = {
 218         .ioctl          = pcf2127_rtc_ioctl,
 219         .read_time      = pcf2127_rtc_read_time,
 220         .set_time       = pcf2127_rtc_set_time,
 221 };
 222
 223 static int pcf2127_nvmem_read(void *priv, unsigned int offset,
 224                               void *val, size_t bytes)
 225 {
 226         struct pcf2127 *pcf2127 = priv;
 227         int ret;
 228         unsigned char offsetbuf[] = { offset >> 8, offset };
 229
 230         ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_ADDR_MSB,
 231                                 offsetbuf, 2);
 232         if (ret)
 233                 return ret;
 234
 235         ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_RAM_RD_CMD,
 236                                val, bytes);
 237
 238         return ret ?: bytes;
 239 }
 240
 241 static int pcf2127_nvmem_write(void *priv, unsigned int offset,
 242                                void *val, size_t bytes)
 243 {
 244         struct pcf2127 *pcf2127 = priv;
 245         int ret;
 246         unsigned char offsetbuf[] = { offset >> 8, offset };
 247
 248         ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_ADDR_MSB,
 249                                 offsetbuf, 2);
 250         if (ret)
 251                 return ret;
 252
 253         ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_WRT_CMD,
 254                                 val, bytes);
 255
 256         return ret ?: bytes;
 257 }
 258
 259 /* watchdog driver */
 260
 261 static int pcf2127_wdt_ping(struct watchdog_device *wdd)
 262 {
 263         struct pcf2127 *pcf2127 = watchdog_get_drvdata(wdd);
 264
 265         return regmap_write(pcf2127->regmap, PCF2127_REG_WD_VAL, wdd->timeout);
 266 }
 267
 268 /*
 269  * Restart watchdog timer if feature is active.
 270  *
 271  * Note: Reading CTRL2 register causes watchdog to stop which is unfortunate,
 272  * since register also contain control/status flags for other features.
 273  * Always call this function after reading CTRL2 register.
 274  */
 275 static int pcf2127_wdt_active_ping(struct watchdog_device *wdd)
 276 {
 277         int ret = 0;
 278
 279         if (watchdog_active(wdd)) {
 280                 ret = pcf2127_wdt_ping(wdd);
 281                 if (ret)
 282                         dev_err(wdd->parent,
 283                                 "%s: watchdog restart failed, ret=%d\n",
 284                                 __func__, ret);
 285         }
 286
 287         return ret;
 288 }
 289
 290 static int pcf2127_wdt_start(struct watchdog_device *wdd)
 291 {
 292         return pcf2127_wdt_ping(wdd);
 293 }
 294
 295 static int pcf2127_wdt_stop(struct watchdog_device *wdd)
 296 {
 297         struct pcf2127 *pcf2127 = watchdog_get_drvdata(wdd);
 298
 299         return regmap_write(pcf2127->regmap, PCF2127_REG_WD_VAL,
 300                             PCF2127_WD_VAL_STOP);
 301 }
 302
 303 static int pcf2127_wdt_set_timeout(struct watchdog_device *wdd,
 304                                    unsigned int new_timeout)
 305 {
 306         dev_dbg(wdd->parent, "new watchdog timeout: %is (old: %is)\n",
 307                 new_timeout, wdd->timeout);
 308
 309         wdd->timeout = new_timeout;
 310
 311         return pcf2127_wdt_active_ping(wdd);
 312 }
 313
 314 static const struct watchdog_info pcf2127_wdt_info = {
 315         .identity = "NXP PCF2127/PCF2129 Watchdog",
 316         .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT,
 317 };
 318
 319 static const struct watchdog_ops pcf2127_watchdog_ops = {
 320         .owner = THIS_MODULE,
 321         .start = pcf2127_wdt_start,
 322         .stop = pcf2127_wdt_stop,
 323         .ping = pcf2127_wdt_ping,
 324         .set_timeout = pcf2127_wdt_set_timeout,
 325 };
 326
 327 /* sysfs interface */
 328
 329 static ssize_t timestamp0_store(struct device *dev,
 330                                 struct device_attribute *attr,
 331                                 const char *buf, size_t count)
 332 {
 333         struct pcf2127 *pcf2127 = dev_get_drvdata(dev->parent);
 334         int ret;
 335
 336         ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL1,
 337                                  PCF2127_BIT_CTRL1_TSF1, 0);
 338         if (ret) {
 339                 dev_err(dev, "%s: update ctrl1 ret=%d\n", __func__, ret);
 340                 return ret;
 341         }
 342
 343         ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL2,
 344                                  PCF2127_BIT_CTRL2_TSF2, 0);
 345         if (ret) {
 346                 dev_err(dev, "%s: update ctrl2 ret=%d\n", __func__, ret);
 347                 return ret;
 348         }
 349
 350         ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
 351         if (ret)
 352                 return ret;
 353
 354         return count;
 355 };
 356
 357 static ssize_t timestamp0_show(struct device *dev,
 358                                struct device_attribute *attr, char *buf)
 359 {
 360         struct pcf2127 *pcf2127 = dev_get_drvdata(dev->parent);
 361         struct rtc_time tm;
 362         int ret;
 363         unsigned char data[25];
 364
 365         ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_CTRL1, data,
 366                                sizeof(data));
 367         if (ret) {
 368                 dev_err(dev, "%s: read error ret=%d\n", __func__, ret);
 369                 return ret;
 370         }
 371
 372         dev_dbg(dev,
 373                 "%s: raw data is cr1=%02x, cr2=%02x, cr3=%02x, ts_sc=%02x, "
 374                 "ts_mn=%02x, ts_hr=%02x, ts_dm=%02x, ts_mo=%02x, ts_yr=%02x\n",
 375                 __func__, data[PCF2127_REG_CTRL1], data[PCF2127_REG_CTRL2],
 376                 data[PCF2127_REG_CTRL3], data[PCF2127_REG_TS_SC],
 377                 data[PCF2127_REG_TS_MN], data[PCF2127_REG_TS_HR],
 378                 data[PCF2127_REG_TS_DM], data[PCF2127_REG_TS_MO],
 379                 data[PCF2127_REG_TS_YR]);
 380
 381         ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
 382         if (ret)
 383                 return ret;
 384
 385         if (!(data[PCF2127_REG_CTRL1] & PCF2127_BIT_CTRL1_TSF1) &&
 386             !(data[PCF2127_REG_CTRL2] & PCF2127_BIT_CTRL2_TSF2))
 387                 return 0;
 388
 389         tm.tm_sec = bcd2bin(data[PCF2127_REG_TS_SC] & 0x7F);
 390         tm.tm_min = bcd2bin(data[PCF2127_REG_TS_MN] & 0x7F);
 391         tm.tm_hour = bcd2bin(data[PCF2127_REG_TS_HR] & 0x3F);
 392         tm.tm_mday = bcd2bin(data[PCF2127_REG_TS_DM] & 0x3F);
 393         /* TS_MO register (month) value range: 1-12 */
 394         tm.tm_mon = bcd2bin(data[PCF2127_REG_TS_MO] & 0x1F) - 1;
 395         tm.tm_year = bcd2bin(data[PCF2127_REG_TS_YR]);
 396         if (tm.tm_year < 70)
 397                 tm.tm_year += 100; /* assume we are in 1970...2069 */
 398
 399         ret = rtc_valid_tm(&tm);
 400         if (ret)
 401                 return ret;
 402
 403         return sprintf(buf, "%llu\n",
 404                        (unsigned long long)rtc_tm_to_time64(&tm));
 405 };
 406
 407 static DEVICE_ATTR_RW(timestamp0);
 408
 409 static struct attribute *pcf2127_attrs[] = {
 410         &dev_attr_timestamp0.attr,
 411         NULL
 412 };
 413
 414 static const struct attribute_group pcf2127_attr_group = {
 415         .attrs  = pcf2127_attrs,
 416 };
 417
 418 static int pcf2127_probe(struct device *dev, struct regmap *regmap,
 419                         const char *name, bool has_nvmem)
 420 {
 421         struct pcf2127 *pcf2127;
 422         u32 wdd_timeout;
 423         int ret = 0;
 424
 425         dev_dbg(dev, "%s\n", __func__);
 426
 427         pcf2127 = devm_kzalloc(dev, sizeof(*pcf2127), GFP_KERNEL);
 428         if (!pcf2127)
 429                 return -ENOMEM;
 430
 431         pcf2127->regmap = regmap;
 432
 433         dev_set_drvdata(dev, pcf2127);
 434
 435         pcf2127->rtc = devm_rtc_allocate_device(dev);
 436         if (IS_ERR(pcf2127->rtc))
 437                 return PTR_ERR(pcf2127->rtc);
 438
 439         pcf2127->rtc->ops = &pcf2127_rtc_ops;
 440         pcf2127->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 441         pcf2127->rtc->range_max = RTC_TIMESTAMP_END_2099;
 442         pcf2127->rtc->set_start_time = true; /* Sets actual start to 1970 */
 443
 444         pcf2127->wdd.parent = dev;
 445         pcf2127->wdd.info = &pcf2127_wdt_info;
 446         pcf2127->wdd.ops = &pcf2127_watchdog_ops;
 447         pcf2127->wdd.min_timeout = PCF2127_WD_VAL_MIN;
 448         pcf2127->wdd.max_timeout = PCF2127_WD_VAL_MAX;
 449         pcf2127->wdd.timeout = PCF2127_WD_VAL_DEFAULT;
 450         pcf2127->wdd.min_hw_heartbeat_ms = 500;
 451         pcf2127->wdd.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
 452
 453         watchdog_set_drvdata(&pcf2127->wdd, pcf2127);
 454
 455         if (has_nvmem) {
 456                 struct nvmem_config nvmem_cfg = {
 457                         .priv = pcf2127,
 458                         .reg_read = pcf2127_nvmem_read,
 459                         .reg_write = pcf2127_nvmem_write,
 460                         .size = 512,
 461                 };
 462
 463                 ret = rtc_nvmem_register(pcf2127->rtc, &nvmem_cfg);
 464         }
 465
 466         /*
 467          * Watchdog timer enabled and reset pin /RST activated when timed out.
 468          * Select 1Hz clock source for watchdog timer.
 469          * Note: Countdown timer disabled and not available.
 470          */
 471         ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_WD_CTL,
 472                                  PCF2127_BIT_WD_CTL_CD1 |
 473                                  PCF2127_BIT_WD_CTL_CD0 |
 474                                  PCF2127_BIT_WD_CTL_TF1 |
 475                                  PCF2127_BIT_WD_CTL_TF0,
 476                                  PCF2127_BIT_WD_CTL_CD1 |
 477                                  PCF2127_BIT_WD_CTL_CD0 |
 478                                  PCF2127_BIT_WD_CTL_TF1);
 479         if (ret) {
 480                 dev_err(dev, "%s: watchdog config (wd_ctl) failed\n", __func__);
 481                 return ret;
 482         }
 483
 484         /* Test if watchdog timer is started by bootloader */
 485         ret = regmap_read(pcf2127->regmap, PCF2127_REG_WD_VAL, &wdd_timeout);
 486         if (ret)
 487                 return ret;
 488
 489         if (wdd_timeout)
 490                 set_bit(WDOG_HW_RUNNING, &pcf2127->wdd.status);
 491
 492 #ifdef CONFIG_WATCHDOG
 493         ret = devm_watchdog_register_device(dev, &pcf2127->wdd);
 494         if (ret)
 495                 return ret;
 496 #endif /* CONFIG_WATCHDOG */
 497
 498         /*
 499          * Disable battery low/switch-over timestamp and interrupts.
 500          * Clear battery interrupt flags which can block new trigger events.
 501          * Note: This is the default chip behaviour but added to ensure
 502          * correct tamper timestamp and interrupt function.
 503          */
 504         ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL3,
 505                                  PCF2127_BIT_CTRL3_BTSE |
 506                                  PCF2127_BIT_CTRL3_BIE |
 507                                  PCF2127_BIT_CTRL3_BLIE, 0);
 508         if (ret) {
 509                 dev_err(dev, "%s: interrupt config (ctrl3) failed\n",
 510                         __func__);
 511                 return ret;
 512         }
 513
 514         /*
 515          * Enable timestamp function and store timestamp of first trigger
 516          * event until TSF1 and TFS2 interrupt flags are cleared.
 517          */
 518         ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_TS_CTRL,
 519                                  PCF2127_BIT_TS_CTRL_TSOFF |
 520                                  PCF2127_BIT_TS_CTRL_TSM,
 521                                  PCF2127_BIT_TS_CTRL_TSM);
 522         if (ret) {
 523                 dev_err(dev, "%s: tamper detection config (ts_ctrl) failed\n",
 524                         __func__);
 525                 return ret;
 526         }
 527
 528         /*
 529          * Enable interrupt generation when TSF1 or TSF2 timestamp flags
 530          * are set. Interrupt signal is an open-drain output and can be
 531          * left floating if unused.
 532          */
 533         ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL2,
 534                                  PCF2127_BIT_CTRL2_TSIE,
 535                                  PCF2127_BIT_CTRL2_TSIE);
 536         if (ret) {
 537                 dev_err(dev, "%s: tamper detection config (ctrl2) failed\n",
 538                         __func__);
 539                 return ret;
 540         }
 541
 542         ret = rtc_add_group(pcf2127->rtc, &pcf2127_attr_group);
 543         if (ret) {
 544                 dev_err(dev, "%s: tamper sysfs registering failed\n",
 545                         __func__);
 546                 return ret;
 547         }
 548
 549         return rtc_register_device(pcf2127->rtc);
 550 }
 551
 552 #ifdef CONFIG_OF
 553 static const struct of_device_id pcf2127_of_match[] = {
 554         { .compatible = "nxp,pcf2127" },
 555         { .compatible = "nxp,pcf2129" },
 556         {}
 557 };
 558 MODULE_DEVICE_TABLE(of, pcf2127_of_match);
 559 #endif
 560
 561 #if IS_ENABLED(CONFIG_I2C)
 562
 563 static int pcf2127_i2c_write(void *context, const void *data, size_t count)
 564 {
 565         struct device *dev = context;
 566         struct i2c_client *client = to_i2c_client(dev);
 567         int ret;
 568
 569         ret = i2c_master_send(client, data, count);
 570         if (ret != count)
 571                 return ret < 0 ? ret : -EIO;
 572
 573         return 0;
 574 }
 575
 576 static int pcf2127_i2c_gather_write(void *context,
 577                                 const void *reg, size_t reg_size,
 578                                 const void *val, size_t val_size)
 579 {
 580         struct device *dev = context;
 581         struct i2c_client *client = to_i2c_client(dev);
 582         int ret;
 583         void *buf;
 584
 585         if (WARN_ON(reg_size != 1))
 586                 return -EINVAL;
 587
 588         buf = kmalloc(val_size + 1, GFP_KERNEL);
 589         if (!buf)
 590                 return -ENOMEM;
 591
 592         memcpy(buf, reg, 1);
 593         memcpy(buf + 1, val, val_size);
 594
 595         ret = i2c_master_send(client, buf, val_size + 1);
 596
 597         kfree(buf);
 598
 599         if (ret != val_size + 1)
 600                 return ret < 0 ? ret : -EIO;
 601
 602         return 0;
 603 }
 604
 605 static int pcf2127_i2c_read(void *context, const void *reg, size_t reg_size,
 606                                 void *val, size_t val_size)
 607 {
 608         struct device *dev = context;
 609         struct i2c_client *client = to_i2c_client(dev);
 610         int ret;
 611
 612         if (WARN_ON(reg_size != 1))
 613                 return -EINVAL;
 614
 615         ret = i2c_master_send(client, reg, 1);
 616         if (ret != 1)
 617                 return ret < 0 ? ret : -EIO;
 618
 619         ret = i2c_master_recv(client, val, val_size);
 620         if (ret != val_size)
 621                 return ret < 0 ? ret : -EIO;
 622
 623         return 0;
 624 }
 625
 626 /*
 627  * The reason we need this custom regmap_bus instead of using regmap_init_i2c()
 628  * is that the STOP condition is required between set register address and
 629  * read register data when reading from registers.
 630  */
 631 static const struct regmap_bus pcf2127_i2c_regmap = {
 632         .write = pcf2127_i2c_write,
 633         .gather_write = pcf2127_i2c_gather_write,
 634         .read = pcf2127_i2c_read,
 635 };
 636
 637 static struct i2c_driver pcf2127_i2c_driver;
 638
 639 static int pcf2127_i2c_probe(struct i2c_client *client,
 640                                 const struct i2c_device_id *id)
 641 {
 642         struct regmap *regmap;
 643         static const struct regmap_config config = {
 644                 .reg_bits = 8,
 645                 .val_bits = 8,
 646                 .max_register = 0x1d,
 647         };
 648
 649         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
 650                 return -ENODEV;
 651
 652         regmap = devm_regmap_init(&client->dev, &pcf2127_i2c_regmap,
 653                                         &client->dev, &config);
 654         if (IS_ERR(regmap)) {
 655                 dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
 656                         __func__, PTR_ERR(regmap));
 657                 return PTR_ERR(regmap);
 658         }
 659
 660         return pcf2127_probe(&client->dev, regmap,
 661                              pcf2127_i2c_driver.driver.name, id->driver_data);
 662 }
 663
 664 static const struct i2c_device_id pcf2127_i2c_id[] = {
 665         { "pcf2127", 1 },
 666         { "pcf2129", 0 },
 667         { }
 668 };
 669 MODULE_DEVICE_TABLE(i2c, pcf2127_i2c_id);
 670
 671 static struct i2c_driver pcf2127_i2c_driver = {
 672         .driver         = {
 673                 .name   = "rtc-pcf2127-i2c",
 674                 .of_match_table = of_match_ptr(pcf2127_of_match),
 675         },
 676         .probe          = pcf2127_i2c_probe,
 677         .id_table       = pcf2127_i2c_id,
 678 };
 679
 680 static int pcf2127_i2c_register_driver(void)
 681 {
 682         return i2c_add_driver(&pcf2127_i2c_driver);
 683 }
 684
 685 static void pcf2127_i2c_unregister_driver(void)
 686 {
 687         i2c_del_driver(&pcf2127_i2c_driver);
 688 }
 689
 690 #else
 691
 692 static int pcf2127_i2c_register_driver(void)
 693 {
 694         return 0;
 695 }
 696
 697 static void pcf2127_i2c_unregister_driver(void)
 698 {
 699 }
 700
 701 #endif
 702
 703 #if IS_ENABLED(CONFIG_SPI_MASTER)
 704
 705 static struct spi_driver pcf2127_spi_driver;
 706
 707 static int pcf2127_spi_probe(struct spi_device *spi)
 708 {
 709         static const struct regmap_config config = {
 710                 .reg_bits = 8,
 711                 .val_bits = 8,
 712                 .read_flag_mask = 0xa0,
 713                 .write_flag_mask = 0x20,
 714                 .max_register = 0x1d,
 715         };
 716         struct regmap *regmap;
 717
 718         regmap = devm_regmap_init_spi(spi, &config);
 719         if (IS_ERR(regmap)) {
 720                 dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
 721                         __func__, PTR_ERR(regmap));
 722                 return PTR_ERR(regmap);
 723         }
 724
 725         return pcf2127_probe(&spi->dev, regmap, pcf2127_spi_driver.driver.name,
 726                              spi_get_device_id(spi)->driver_data);
 727 }
 728
 729 static const struct spi_device_id pcf2127_spi_id[] = {
 730         { "pcf2127", 1 },
 731         { "pcf2129", 0 },
 732         { }
 733 };
 734 MODULE_DEVICE_TABLE(spi, pcf2127_spi_id);
 735
 736 static struct spi_driver pcf2127_spi_driver = {
 737         .driver         = {
 738                 .name   = "rtc-pcf2127-spi",
 739                 .of_match_table = of_match_ptr(pcf2127_of_match),
 740         },
 741         .probe          = pcf2127_spi_probe,
 742         .id_table       = pcf2127_spi_id,
 743 };
 744
 745 static int pcf2127_spi_register_driver(void)
 746 {
 747         return spi_register_driver(&pcf2127_spi_driver);
 748 }
 749
 750 static void pcf2127_spi_unregister_driver(void)
 751 {
 752         spi_unregister_driver(&pcf2127_spi_driver);
 753 }
 754
 755 #else
 756
 757 static int pcf2127_spi_register_driver(void)
 758 {
 759         return 0;
 760 }
 761
 762 static void pcf2127_spi_unregister_driver(void)
 763 {
 764 }
 765
 766 #endif
 767
 768 static int __init pcf2127_init(void)
 769 {
 770         int ret;
 771
 772         ret = pcf2127_i2c_register_driver();
 773         if (ret) {
 774                 pr_err("Failed to register pcf2127 i2c driver: %d\n", ret);
 775                 return ret;
 776         }
 777
 778         ret = pcf2127_spi_register_driver();
 779         if (ret) {
 780                 pr_err("Failed to register pcf2127 spi driver: %d\n", ret);
 781                 pcf2127_i2c_unregister_driver();
 782         }
 783
 784         return ret;
 785 }
 786 module_init(pcf2127_init)
 787
 788 static void __exit pcf2127_exit(void)
 789 {
 790         pcf2127_spi_unregister_driver();
 791         pcf2127_i2c_unregister_driver();
 792 }
 793 module_exit(pcf2127_exit)
 794
 795 MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>");
 796 MODULE_DESCRIPTION("NXP PCF2127/29 RTC driver");
 797 MODULE_LICENSE("GPL v2");