drivers/rtc/rtc-mpc5121.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Real-time clock driver for MPC5121
   4  *
   5  * Copyright 2007, Domen Puncer <domen.puncer@telargo.com>
   6  * Copyright 2008, Freescale Semiconductor, Inc. All rights reserved.
   7  * Copyright 2011, Dmitry Eremin-Solenikov
   8  */
   9
  10 #include <linux/init.h>
  11 #include <linux/module.h>
  12 #include <linux/rtc.h>
  13 #include <linux/of.h>
  14 #include <linux/of_address.h>
  15 #include <linux/of_device.h>
  16 #include <linux/of_irq.h>
  17 #include <linux/of_platform.h>
  18 #include <linux/io.h>
  19 #include <linux/slab.h>
  20
  21 struct mpc5121_rtc_regs {
  22         u8 set_time;            /* RTC + 0x00 */
  23         u8 hour_set;            /* RTC + 0x01 */
  24         u8 minute_set;          /* RTC + 0x02 */
  25         u8 second_set;          /* RTC + 0x03 */
  26
  27         u8 set_date;            /* RTC + 0x04 */
  28         u8 month_set;           /* RTC + 0x05 */
  29         u8 weekday_set;         /* RTC + 0x06 */
  30         u8 date_set;            /* RTC + 0x07 */
  31
  32         u8 write_sw;            /* RTC + 0x08 */
  33         u8 sw_set;              /* RTC + 0x09 */
  34         u16 year_set;           /* RTC + 0x0a */
  35
  36         u8 alm_enable;          /* RTC + 0x0c */
  37         u8 alm_hour_set;        /* RTC + 0x0d */
  38         u8 alm_min_set;         /* RTC + 0x0e */
  39         u8 int_enable;          /* RTC + 0x0f */
  40
  41         u8 reserved1;
  42         u8 hour;                /* RTC + 0x11 */
  43         u8 minute;              /* RTC + 0x12 */
  44         u8 second;              /* RTC + 0x13 */
  45
  46         u8 month;               /* RTC + 0x14 */
  47         u8 wday_mday;           /* RTC + 0x15 */
  48         u16 year;               /* RTC + 0x16 */
  49
  50         u8 int_alm;             /* RTC + 0x18 */
  51         u8 int_sw;              /* RTC + 0x19 */
  52         u8 alm_status;          /* RTC + 0x1a */
  53         u8 sw_minute;           /* RTC + 0x1b */
  54
  55         u8 bus_error_1;         /* RTC + 0x1c */
  56         u8 int_day;             /* RTC + 0x1d */
  57         u8 int_min;             /* RTC + 0x1e */
  58         u8 int_sec;             /* RTC + 0x1f */
  59
  60         /*
  61          * target_time:
  62          *      intended to be used for hibernation but hibernation
  63          *      does not work on silicon rev 1.5 so use it for non-volatile
  64          *      storage of offset between the actual_time register and linux
  65          *      time
  66          */
  67         u32 target_time;        /* RTC + 0x20 */
  68         /*
  69          * actual_time:
  70          *      readonly time since VBAT_RTC was last connected
  71          */
  72         u32 actual_time;        /* RTC + 0x24 */
  73         u32 keep_alive;         /* RTC + 0x28 */
  74 };
  75
  76 struct mpc5121_rtc_data {
  77         unsigned irq;
  78         unsigned irq_periodic;
  79         struct mpc5121_rtc_regs __iomem *regs;
  80         struct rtc_device *rtc;
  81         struct rtc_wkalrm wkalarm;
  82 };
  83
  84 /*
  85  * Update second/minute/hour registers.
  86  *
  87  * This is just so alarm will work.
  88  */
  89 static void mpc5121_rtc_update_smh(struct mpc5121_rtc_regs __iomem *regs,
  90                                    struct rtc_time *tm)
  91 {
  92         out_8(&regs->second_set, tm->tm_sec);
  93         out_8(&regs->minute_set, tm->tm_min);
  94         out_8(&regs->hour_set, tm->tm_hour);
  95
  96         /* set time sequence */
  97         out_8(&regs->set_time, 0x1);
  98         out_8(&regs->set_time, 0x3);
  99         out_8(&regs->set_time, 0x1);
 100         out_8(&regs->set_time, 0x0);
 101 }
 102
 103 static int mpc5121_rtc_read_time(struct device *dev, struct rtc_time *tm)
 104 {
 105         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 106         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 107         unsigned long now;
 108
 109         /*
 110          * linux time is actual_time plus the offset saved in target_time
 111          */
 112         now = in_be32(&regs->actual_time) + in_be32(&regs->target_time);
 113
 114         rtc_time_to_tm(now, tm);
 115
 116         /*
 117          * update second minute hour registers
 118          * so alarms will work
 119          */
 120         mpc5121_rtc_update_smh(regs, tm);
 121
 122         return 0;
 123 }
 124
 125 static int mpc5121_rtc_set_time(struct device *dev, struct rtc_time *tm)
 126 {
 127         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 128         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 129         int ret;
 130         unsigned long now;
 131
 132         /*
 133          * The actual_time register is read only so we write the offset
 134          * between it and linux time to the target_time register.
 135          */
 136         ret = rtc_tm_to_time(tm, &now);
 137         if (ret == 0)
 138                 out_be32(&regs->target_time, now - in_be32(&regs->actual_time));
 139
 140         /*
 141          * update second minute hour registers
 142          * so alarms will work
 143          */
 144         mpc5121_rtc_update_smh(regs, tm);
 145
 146         return 0;
 147 }
 148
 149 static int mpc5200_rtc_read_time(struct device *dev, struct rtc_time *tm)
 150 {
 151         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 152         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 153         int tmp;
 154
 155         tm->tm_sec = in_8(&regs->second);
 156         tm->tm_min = in_8(&regs->minute);
 157
 158         /* 12 hour format? */
 159         if (in_8(&regs->hour) & 0x20)
 160                 tm->tm_hour = (in_8(&regs->hour) >> 1) +
 161                         (in_8(&regs->hour) & 1 ? 12 : 0);
 162         else
 163                 tm->tm_hour = in_8(&regs->hour);
 164
 165         tmp = in_8(&regs->wday_mday);
 166         tm->tm_mday = tmp & 0x1f;
 167         tm->tm_mon = in_8(&regs->month) - 1;
 168         tm->tm_year = in_be16(&regs->year) - 1900;
 169         tm->tm_wday = (tmp >> 5) % 7;
 170         tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
 171         tm->tm_isdst = 0;
 172
 173         return 0;
 174 }
 175
 176 static int mpc5200_rtc_set_time(struct device *dev, struct rtc_time *tm)
 177 {
 178         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 179         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 180
 181         mpc5121_rtc_update_smh(regs, tm);
 182
 183         /* date */
 184         out_8(&regs->month_set, tm->tm_mon + 1);
 185         out_8(&regs->weekday_set, tm->tm_wday ? tm->tm_wday : 7);
 186         out_8(&regs->date_set, tm->tm_mday);
 187         out_be16(&regs->year_set, tm->tm_year + 1900);
 188
 189         /* set date sequence */
 190         out_8(&regs->set_date, 0x1);
 191         out_8(&regs->set_date, 0x3);
 192         out_8(&regs->set_date, 0x1);
 193         out_8(&regs->set_date, 0x0);
 194
 195         return 0;
 196 }
 197
 198 static int mpc5121_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 199 {
 200         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 201         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 202
 203         *alarm = rtc->wkalarm;
 204
 205         alarm->pending = in_8(&regs->alm_status);
 206
 207         return 0;
 208 }
 209
 210 static int mpc5121_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 211 {
 212         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 213         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 214
 215         /*
 216          * the alarm has no seconds so deal with it
 217          */
 218         if (alarm->time.tm_sec) {
 219                 alarm->time.tm_sec = 0;
 220                 alarm->time.tm_min++;
 221                 if (alarm->time.tm_min >= 60) {
 222                         alarm->time.tm_min = 0;
 223                         alarm->time.tm_hour++;
 224                         if (alarm->time.tm_hour >= 24)
 225                                 alarm->time.tm_hour = 0;
 226                 }
 227         }
 228
 229         alarm->time.tm_mday = -1;
 230         alarm->time.tm_mon = -1;
 231         alarm->time.tm_year = -1;
 232
 233         out_8(&regs->alm_min_set, alarm->time.tm_min);
 234         out_8(&regs->alm_hour_set, alarm->time.tm_hour);
 235
 236         out_8(&regs->alm_enable, alarm->enabled);
 237
 238         rtc->wkalarm = *alarm;
 239         return 0;
 240 }
 241
 242 static irqreturn_t mpc5121_rtc_handler(int irq, void *dev)
 243 {
 244         struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
 245         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 246
 247         if (in_8(&regs->int_alm)) {
 248                 /* acknowledge and clear status */
 249                 out_8(&regs->int_alm, 1);
 250                 out_8(&regs->alm_status, 1);
 251
 252                 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
 253                 return IRQ_HANDLED;
 254         }
 255
 256         return IRQ_NONE;
 257 }
 258
 259 static irqreturn_t mpc5121_rtc_handler_upd(int irq, void *dev)
 260 {
 261         struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
 262         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 263
 264         if (in_8(&regs->int_sec) && (in_8(&regs->int_enable) & 0x1)) {
 265                 /* acknowledge */
 266                 out_8(&regs->int_sec, 1);
 267
 268                 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_UF);
 269                 return IRQ_HANDLED;
 270         }
 271
 272         return IRQ_NONE;
 273 }
 274
 275 static int mpc5121_rtc_alarm_irq_enable(struct device *dev,
 276                                         unsigned int enabled)
 277 {
 278         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 279         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 280         int val;
 281
 282         if (enabled)
 283                 val = 1;
 284         else
 285                 val = 0;
 286
 287         out_8(&regs->alm_enable, val);
 288         rtc->wkalarm.enabled = val;
 289
 290         return 0;
 291 }
 292
 293 static const struct rtc_class_ops mpc5121_rtc_ops = {
 294         .read_time = mpc5121_rtc_read_time,
 295         .set_time = mpc5121_rtc_set_time,
 296         .read_alarm = mpc5121_rtc_read_alarm,
 297         .set_alarm = mpc5121_rtc_set_alarm,
 298         .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
 299 };
 300
 301 static const struct rtc_class_ops mpc5200_rtc_ops = {
 302         .read_time = mpc5200_rtc_read_time,
 303         .set_time = mpc5200_rtc_set_time,
 304         .read_alarm = mpc5121_rtc_read_alarm,
 305         .set_alarm = mpc5121_rtc_set_alarm,
 306         .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
 307 };
 308
 309 static int mpc5121_rtc_probe(struct platform_device *op)
 310 {
 311         struct mpc5121_rtc_data *rtc;
 312         int err = 0;
 313
 314         rtc = devm_kzalloc(&op->dev, sizeof(*rtc), GFP_KERNEL);
 315         if (!rtc)
 316                 return -ENOMEM;
 317
 318         rtc->regs = of_iomap(op->dev.of_node, 0);
 319         if (!rtc->regs) {
 320                 dev_err(&op->dev, "%s: couldn't map io space\n", __func__);
 321                 return -ENOSYS;
 322         }
 323
 324         device_init_wakeup(&op->dev, 1);
 325
 326         platform_set_drvdata(op, rtc);
 327
 328         rtc->irq = irq_of_parse_and_map(op->dev.of_node, 1);
 329         err = request_irq(rtc->irq, mpc5121_rtc_handler, 0,
 330                                                 "mpc5121-rtc", &op->dev);
 331         if (err) {
 332                 dev_err(&op->dev, "%s: could not request irq: %i\n",
 333                                                         __func__, rtc->irq);
 334                 goto out_dispose;
 335         }
 336
 337         rtc->irq_periodic = irq_of_parse_and_map(op->dev.of_node, 0);
 338         err = request_irq(rtc->irq_periodic, mpc5121_rtc_handler_upd,
 339                                 0, "mpc5121-rtc_upd", &op->dev);
 340         if (err) {
 341                 dev_err(&op->dev, "%s: could not request irq: %i\n",
 342                                                 __func__, rtc->irq_periodic);
 343                 goto out_dispose2;
 344         }
 345
 346         if (of_device_is_compatible(op->dev.of_node, "fsl,mpc5121-rtc")) {
 347                 u32 ka;
 348                 ka = in_be32(&rtc->regs->keep_alive);
 349                 if (ka & 0x02) {
 350                         dev_warn(&op->dev,
 351                                 "mpc5121-rtc: Battery or oscillator failure!\n");
 352                         out_be32(&rtc->regs->keep_alive, ka);
 353                 }
 354
 355                 rtc->rtc = devm_rtc_device_register(&op->dev, "mpc5121-rtc",
 356                                                 &mpc5121_rtc_ops, THIS_MODULE);
 357         } else {
 358                 rtc->rtc = devm_rtc_device_register(&op->dev, "mpc5200-rtc",
 359                                                 &mpc5200_rtc_ops, THIS_MODULE);
 360         }
 361
 362         if (IS_ERR(rtc->rtc)) {
 363                 err = PTR_ERR(rtc->rtc);
 364                 goto out_free_irq;
 365         }
 366         rtc->rtc->uie_unsupported = 1;
 367
 368         return 0;
 369
 370 out_free_irq:
 371         free_irq(rtc->irq_periodic, &op->dev);
 372 out_dispose2:
 373         irq_dispose_mapping(rtc->irq_periodic);
 374         free_irq(rtc->irq, &op->dev);
 375 out_dispose:
 376         irq_dispose_mapping(rtc->irq);
 377         iounmap(rtc->regs);
 378
 379         return err;
 380 }
 381
 382 static int mpc5121_rtc_remove(struct platform_device *op)
 383 {
 384         struct mpc5121_rtc_data *rtc = platform_get_drvdata(op);
 385         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 386
 387         /* disable interrupt, so there are no nasty surprises */
 388         out_8(&regs->alm_enable, 0);
 389         out_8(&regs->int_enable, in_8(&regs->int_enable) & ~0x1);
 390
 391         iounmap(rtc->regs);
 392         free_irq(rtc->irq, &op->dev);
 393         free_irq(rtc->irq_periodic, &op->dev);
 394         irq_dispose_mapping(rtc->irq);
 395         irq_dispose_mapping(rtc->irq_periodic);
 396
 397         return 0;
 398 }
 399
 400 #ifdef CONFIG_OF
 401 static const struct of_device_id mpc5121_rtc_match[] = {
 402         { .compatible = "fsl,mpc5121-rtc", },
 403         { .compatible = "fsl,mpc5200-rtc", },
 404         {},
 405 };
 406 MODULE_DEVICE_TABLE(of, mpc5121_rtc_match);
 407 #endif
 408
 409 static struct platform_driver mpc5121_rtc_driver = {
 410         .driver = {
 411                 .name = "mpc5121-rtc",
 412                 .of_match_table = of_match_ptr(mpc5121_rtc_match),
 413         },
 414         .probe = mpc5121_rtc_probe,
 415         .remove = mpc5121_rtc_remove,
 416 };
 417
 418 module_platform_driver(mpc5121_rtc_driver);
 419
 420 MODULE_LICENSE("GPL");
 421 MODULE_AUTHOR("John Rigby <jcrigby@gmail.com>");