drivers/rtc/rtc-88pm860x.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Real Time Clock driver for Marvell 88PM860x PMIC
   4  *
   5  * Copyright (c) 2010 Marvell International Ltd.
   6  * Author:      Haojian Zhuang <haojian.zhuang@marvell.com>
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/of.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/slab.h>
  14 #include <linux/mutex.h>
  15 #include <linux/rtc.h>
  16 #include <linux/delay.h>
  17 #include <linux/mfd/core.h>
  18 #include <linux/mfd/88pm860x.h>
  19
  20 #define VRTC_CALIBRATION
  21
  22 struct pm860x_rtc_info {
  23         struct pm860x_chip      *chip;
  24         struct i2c_client       *i2c;
  25         struct rtc_device       *rtc_dev;
  26         struct device           *dev;
  27         struct delayed_work     calib_work;
  28
  29         int                     irq;
  30         int                     vrtc;
  31         int                     (*sync)(unsigned int ticks);
  32 };
  33
  34 #define REG_VRTC_MEAS1          0x7D
  35
  36 #define REG0_ADDR               0xB0
  37 #define REG1_ADDR               0xB2
  38 #define REG2_ADDR               0xB4
  39 #define REG3_ADDR               0xB6
  40
  41 #define REG0_DATA               0xB1
  42 #define REG1_DATA               0xB3
  43 #define REG2_DATA               0xB5
  44 #define REG3_DATA               0xB7
  45
  46 /* bit definitions of Measurement Enable Register 2 (0x51) */
  47 #define MEAS2_VRTC              (1 << 0)
  48
  49 /* bit definitions of RTC Register 1 (0xA0) */
  50 #define ALARM_EN                (1 << 3)
  51 #define ALARM_WAKEUP            (1 << 4)
  52 #define ALARM                   (1 << 5)
  53 #define RTC1_USE_XO             (1 << 7)
  54
  55 #define VRTC_CALIB_INTERVAL     (HZ * 60 * 10)          /* 10 minutes */
  56
  57 static irqreturn_t rtc_update_handler(int irq, void *data)
  58 {
  59         struct pm860x_rtc_info *info = (struct pm860x_rtc_info *)data;
  60         int mask;
  61
  62         mask = ALARM | ALARM_WAKEUP;
  63         pm860x_set_bits(info->i2c, PM8607_RTC1, mask | ALARM_EN, mask);
  64         rtc_update_irq(info->rtc_dev, 1, RTC_AF);
  65         return IRQ_HANDLED;
  66 }
  67
  68 static int pm860x_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
  69 {
  70         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
  71
  72         if (enabled)
  73                 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, ALARM_EN);
  74         else
  75                 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0);
  76         return 0;
  77 }
  78
  79 /*
  80  * Calculate the next alarm time given the requested alarm time mask
  81  * and the current time.
  82  */
  83 static void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now,
  84                                 struct rtc_time *alrm)
  85 {
  86         unsigned long next_time;
  87         unsigned long now_time;
  88
  89         next->tm_year = now->tm_year;
  90         next->tm_mon = now->tm_mon;
  91         next->tm_mday = now->tm_mday;
  92         next->tm_hour = alrm->tm_hour;
  93         next->tm_min = alrm->tm_min;
  94         next->tm_sec = alrm->tm_sec;
  95
  96         rtc_tm_to_time(now, &now_time);
  97         rtc_tm_to_time(next, &next_time);
  98
  99         if (next_time < now_time) {
 100                 /* Advance one day */
 101                 next_time += 60 * 60 * 24;
 102                 rtc_time_to_tm(next_time, next);
 103         }
 104 }
 105
 106 static int pm860x_rtc_read_time(struct device *dev, struct rtc_time *tm)
 107 {
 108         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
 109         unsigned char buf[8];
 110         unsigned long ticks, base, data;
 111
 112         pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
 113         dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
 114                 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
 115         base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
 116                 (buf[5] << 8) | buf[7];
 117
 118         /* load 32-bit read-only counter */
 119         pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
 120         data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
 121                 (buf[1] << 8) | buf[0];
 122         ticks = base + data;
 123         dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
 124                 base, data, ticks);
 125
 126         rtc_time_to_tm(ticks, tm);
 127
 128         return 0;
 129 }
 130
 131 static int pm860x_rtc_set_time(struct device *dev, struct rtc_time *tm)
 132 {
 133         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
 134         unsigned char buf[4];
 135         unsigned long ticks, base, data;
 136
 137         if (tm->tm_year > 206) {
 138                 dev_dbg(info->dev, "Set time %d out of range. "
 139                         "Please set time between 1970 to 2106.\n",
 140                         1900 + tm->tm_year);
 141                 return -EINVAL;
 142         }
 143         rtc_tm_to_time(tm, &ticks);
 144
 145         /* load 32-bit read-only counter */
 146         pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
 147         data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
 148                 (buf[1] << 8) | buf[0];
 149         base = ticks - data;
 150         dev_dbg(info->dev, "set base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
 151                 base, data, ticks);
 152
 153         pm860x_page_reg_write(info->i2c, REG0_DATA, (base >> 24) & 0xFF);
 154         pm860x_page_reg_write(info->i2c, REG1_DATA, (base >> 16) & 0xFF);
 155         pm860x_page_reg_write(info->i2c, REG2_DATA, (base >> 8) & 0xFF);
 156         pm860x_page_reg_write(info->i2c, REG3_DATA, base & 0xFF);
 157
 158         if (info->sync)
 159                 info->sync(ticks);
 160         return 0;
 161 }
 162
 163 static int pm860x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 164 {
 165         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
 166         unsigned char buf[8];
 167         unsigned long ticks, base, data;
 168         int ret;
 169
 170         pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
 171         dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
 172                 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
 173         base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
 174                 (buf[5] << 8) | buf[7];
 175
 176         pm860x_bulk_read(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
 177         data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
 178                 (buf[1] << 8) | buf[0];
 179         ticks = base + data;
 180         dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
 181                 base, data, ticks);
 182
 183         rtc_time_to_tm(ticks, &alrm->time);
 184         ret = pm860x_reg_read(info->i2c, PM8607_RTC1);
 185         alrm->enabled = (ret & ALARM_EN) ? 1 : 0;
 186         alrm->pending = (ret & (ALARM | ALARM_WAKEUP)) ? 1 : 0;
 187         return 0;
 188 }
 189
 190 static int pm860x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 191 {
 192         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
 193         struct rtc_time now_tm, alarm_tm;
 194         unsigned long ticks, base, data;
 195         unsigned char buf[8];
 196         int mask;
 197
 198         pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0);
 199
 200         pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
 201         dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
 202                 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
 203         base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
 204                 (buf[5] << 8) | buf[7];
 205
 206         /* load 32-bit read-only counter */
 207         pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
 208         data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
 209                 (buf[1] << 8) | buf[0];
 210         ticks = base + data;
 211         dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
 212                 base, data, ticks);
 213
 214         rtc_time_to_tm(ticks, &now_tm);
 215         rtc_next_alarm_time(&alarm_tm, &now_tm, &alrm->time);
 216         /* get new ticks for alarm in 24 hours */
 217         rtc_tm_to_time(&alarm_tm, &ticks);
 218         data = ticks - base;
 219
 220         buf[0] = data & 0xff;
 221         buf[1] = (data >> 8) & 0xff;
 222         buf[2] = (data >> 16) & 0xff;
 223         buf[3] = (data >> 24) & 0xff;
 224         pm860x_bulk_write(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
 225         if (alrm->enabled) {
 226                 mask = ALARM | ALARM_WAKEUP | ALARM_EN;
 227                 pm860x_set_bits(info->i2c, PM8607_RTC1, mask, mask);
 228         } else {
 229                 mask = ALARM | ALARM_WAKEUP | ALARM_EN;
 230                 pm860x_set_bits(info->i2c, PM8607_RTC1, mask,
 231                                 ALARM | ALARM_WAKEUP);
 232         }
 233         return 0;
 234 }
 235
 236 static const struct rtc_class_ops pm860x_rtc_ops = {
 237         .read_time      = pm860x_rtc_read_time,
 238         .set_time       = pm860x_rtc_set_time,
 239         .read_alarm     = pm860x_rtc_read_alarm,
 240         .set_alarm      = pm860x_rtc_set_alarm,
 241         .alarm_irq_enable = pm860x_rtc_alarm_irq_enable,
 242 };
 243
 244 #ifdef VRTC_CALIBRATION
 245 static void calibrate_vrtc_work(struct work_struct *work)
 246 {
 247         struct pm860x_rtc_info *info = container_of(work,
 248                 struct pm860x_rtc_info, calib_work.work);
 249         unsigned char buf[2];
 250         unsigned int sum, data, mean, vrtc_set;
 251         int i;
 252
 253         for (i = 0, sum = 0; i < 16; i++) {
 254                 msleep(100);
 255                 pm860x_bulk_read(info->i2c, REG_VRTC_MEAS1, 2, buf);
 256                 data = (buf[0] << 4) | buf[1];
 257                 data = (data * 5400) >> 12;     /* convert to mv */
 258                 sum += data;
 259         }
 260         mean = sum >> 4;
 261         vrtc_set = 2700 + (info->vrtc & 0x3) * 200;
 262         dev_dbg(info->dev, "mean:%d, vrtc_set:%d\n", mean, vrtc_set);
 263
 264         sum = pm860x_reg_read(info->i2c, PM8607_RTC_MISC1);
 265         data = sum & 0x3;
 266         if ((mean + 200) < vrtc_set) {
 267                 /* try higher voltage */
 268                 if (++data == 4)
 269                         goto out;
 270                 data = (sum & 0xf8) | (data & 0x3);
 271                 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
 272         } else if ((mean - 200) > vrtc_set) {
 273                 /* try lower voltage */
 274                 if (data-- == 0)
 275                         goto out;
 276                 data = (sum & 0xf8) | (data & 0x3);
 277                 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
 278         } else
 279                 goto out;
 280         dev_dbg(info->dev, "set 0x%x to RTC_MISC1\n", data);
 281         /* trigger next calibration since VRTC is updated */
 282         schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
 283         return;
 284 out:
 285         /* disable measurement */
 286         pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
 287         dev_dbg(info->dev, "finish VRTC calibration\n");
 288         return;
 289 }
 290 #endif
 291
 292 #ifdef CONFIG_OF
 293 static int pm860x_rtc_dt_init(struct platform_device *pdev,
 294                               struct pm860x_rtc_info *info)
 295 {
 296         struct device_node *np = pdev->dev.parent->of_node;
 297         int ret;
 298         if (!np)
 299                 return -ENODEV;
 300         np = of_get_child_by_name(np, "rtc");
 301         if (!np) {
 302                 dev_err(&pdev->dev, "failed to find rtc node\n");
 303                 return -ENODEV;
 304         }
 305         ret = of_property_read_u32(np, "marvell,88pm860x-vrtc", &info->vrtc);
 306         if (ret)
 307                 info->vrtc = 0;
 308         of_node_put(np);
 309         return 0;
 310 }
 311 #else
 312 #define pm860x_rtc_dt_init(x, y)        (-1)
 313 #endif
 314
 315 static int pm860x_rtc_probe(struct platform_device *pdev)
 316 {
 317         struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
 318         struct pm860x_rtc_pdata *pdata = NULL;
 319         struct pm860x_rtc_info *info;
 320         struct rtc_time tm;
 321         unsigned long ticks = 0;
 322         int ret;
 323
 324         pdata = dev_get_platdata(&pdev->dev);
 325
 326         info = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_rtc_info),
 327                             GFP_KERNEL);
 328         if (!info)
 329                 return -ENOMEM;
 330         info->irq = platform_get_irq(pdev, 0);
 331         if (info->irq < 0)
 332                 return info->irq;
 333
 334         info->chip = chip;
 335         info->i2c = (chip->id == CHIP_PM8607) ? chip->client : chip->companion;
 336         info->dev = &pdev->dev;
 337         dev_set_drvdata(&pdev->dev, info);
 338
 339         ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
 340                                         rtc_update_handler, IRQF_ONESHOT, "rtc",
 341                                         info);
 342         if (ret < 0) {
 343                 dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
 344                         info->irq, ret);
 345                 return ret;
 346         }
 347
 348         /* set addresses of 32-bit base value for RTC time */
 349         pm860x_page_reg_write(info->i2c, REG0_ADDR, REG0_DATA);
 350         pm860x_page_reg_write(info->i2c, REG1_ADDR, REG1_DATA);
 351         pm860x_page_reg_write(info->i2c, REG2_ADDR, REG2_DATA);
 352         pm860x_page_reg_write(info->i2c, REG3_ADDR, REG3_DATA);
 353
 354         ret = pm860x_rtc_read_time(&pdev->dev, &tm);
 355         if (ret < 0) {
 356                 dev_err(&pdev->dev, "Failed to read initial time.\n");
 357                 return ret;
 358         }
 359         if ((tm.tm_year < 70) || (tm.tm_year > 138)) {
 360                 tm.tm_year = 70;
 361                 tm.tm_mon = 0;
 362                 tm.tm_mday = 1;
 363                 tm.tm_hour = 0;
 364                 tm.tm_min = 0;
 365                 tm.tm_sec = 0;
 366                 ret = pm860x_rtc_set_time(&pdev->dev, &tm);
 367                 if (ret < 0) {
 368                         dev_err(&pdev->dev, "Failed to set initial time.\n");
 369                         return ret;
 370                 }
 371         }
 372         rtc_tm_to_time(&tm, &ticks);
 373         if (pm860x_rtc_dt_init(pdev, info)) {
 374                 if (pdata && pdata->sync) {
 375                         pdata->sync(ticks);
 376                         info->sync = pdata->sync;
 377                 }
 378         }
 379
 380         info->rtc_dev = devm_rtc_device_register(&pdev->dev, "88pm860x-rtc",
 381                                             &pm860x_rtc_ops, THIS_MODULE);
 382         ret = PTR_ERR(info->rtc_dev);
 383         if (IS_ERR(info->rtc_dev)) {
 384                 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
 385                 return ret;
 386         }
 387
 388         /*
 389          * enable internal XO instead of internal 3.25MHz clock since it can
 390          * free running in PMIC power-down state.
 391          */
 392         pm860x_set_bits(info->i2c, PM8607_RTC1, RTC1_USE_XO, RTC1_USE_XO);
 393
 394 #ifdef VRTC_CALIBRATION
 395         /* <00> -- 2.7V, <01> -- 2.9V, <10> -- 3.1V, <11> -- 3.3V */
 396         if (pm860x_rtc_dt_init(pdev, info)) {
 397                 if (pdata && pdata->vrtc)
 398                         info->vrtc = pdata->vrtc & 0x3;
 399                 else
 400                         info->vrtc = 1;
 401         }
 402         pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, MEAS2_VRTC);
 403
 404         /* calibrate VRTC */
 405         INIT_DELAYED_WORK(&info->calib_work, calibrate_vrtc_work);
 406         schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
 407 #endif  /* VRTC_CALIBRATION */
 408
 409         device_init_wakeup(&pdev->dev, 1);
 410
 411         return 0;
 412 }
 413
 414 static int pm860x_rtc_remove(struct platform_device *pdev)
 415 {
 416         struct pm860x_rtc_info *info = platform_get_drvdata(pdev);
 417
 418 #ifdef VRTC_CALIBRATION
 419         cancel_delayed_work_sync(&info->calib_work);
 420         /* disable measurement */
 421         pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
 422 #endif  /* VRTC_CALIBRATION */
 423
 424         return 0;
 425 }
 426
 427 #ifdef CONFIG_PM_SLEEP
 428 static int pm860x_rtc_suspend(struct device *dev)
 429 {
 430         struct platform_device *pdev = to_platform_device(dev);
 431         struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
 432
 433         if (device_may_wakeup(dev))
 434                 chip->wakeup_flag |= 1 << PM8607_IRQ_RTC;
 435         return 0;
 436 }
 437 static int pm860x_rtc_resume(struct device *dev)
 438 {
 439         struct platform_device *pdev = to_platform_device(dev);
 440         struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
 441
 442         if (device_may_wakeup(dev))
 443                 chip->wakeup_flag &= ~(1 << PM8607_IRQ_RTC);
 444         return 0;
 445 }
 446 #endif
 447
 448 static SIMPLE_DEV_PM_OPS(pm860x_rtc_pm_ops, pm860x_rtc_suspend, pm860x_rtc_resume);
 449
 450 static struct platform_driver pm860x_rtc_driver = {
 451         .driver         = {
 452                 .name   = "88pm860x-rtc",
 453                 .pm     = &pm860x_rtc_pm_ops,
 454         },
 455         .probe          = pm860x_rtc_probe,
 456         .remove         = pm860x_rtc_remove,
 457 };
 458
 459 module_platform_driver(pm860x_rtc_driver);
 460
 461 MODULE_DESCRIPTION("Marvell 88PM860x RTC driver");
 462 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
 463 MODULE_LICENSE("GPL");