drivers/rtc/rtc-mpc5121.c

   1 /*
   2  * Real-time clock driver for MPC5121
   3  *
   4  * Copyright 2007, Domen Puncer <domen.puncer@telargo.com>
   5  * Copyright 2008, Freescale Semiconductor, Inc. All rights reserved.
   6  * Copyright 2011, Dmitry Eremin-Solenikov
   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
  13 #include <linux/init.h>
  14 #include <linux/module.h>
  15 #include <linux/rtc.h>
  16 #include <linux/of.h>
  17 #include <linux/of_address.h>
  18 #include <linux/of_device.h>
  19 #include <linux/of_irq.h>
  20 #include <linux/of_platform.h>
  21 #include <linux/io.h>
  22 #include <linux/slab.h>
  23
  24 struct mpc5121_rtc_regs {
  25         u8 set_time;            /* RTC + 0x00 */
  26         u8 hour_set;            /* RTC + 0x01 */
  27         u8 minute_set;          /* RTC + 0x02 */
  28         u8 second_set;          /* RTC + 0x03 */
  29
  30         u8 set_date;            /* RTC + 0x04 */
  31         u8 month_set;           /* RTC + 0x05 */
  32         u8 weekday_set;         /* RTC + 0x06 */
  33         u8 date_set;            /* RTC + 0x07 */
  34
  35         u8 write_sw;            /* RTC + 0x08 */
  36         u8 sw_set;              /* RTC + 0x09 */
  37         u16 year_set;           /* RTC + 0x0a */
  38
  39         u8 alm_enable;          /* RTC + 0x0c */
  40         u8 alm_hour_set;        /* RTC + 0x0d */
  41         u8 alm_min_set;         /* RTC + 0x0e */
  42         u8 int_enable;          /* RTC + 0x0f */
  43
  44         u8 reserved1;
  45         u8 hour;                /* RTC + 0x11 */
  46         u8 minute;              /* RTC + 0x12 */
  47         u8 second;              /* RTC + 0x13 */
  48
  49         u8 month;               /* RTC + 0x14 */
  50         u8 wday_mday;           /* RTC + 0x15 */
  51         u16 year;               /* RTC + 0x16 */
  52
  53         u8 int_alm;             /* RTC + 0x18 */
  54         u8 int_sw;              /* RTC + 0x19 */
  55         u8 alm_status;          /* RTC + 0x1a */
  56         u8 sw_minute;           /* RTC + 0x1b */
  57
  58         u8 bus_error_1;         /* RTC + 0x1c */
  59         u8 int_day;             /* RTC + 0x1d */
  60         u8 int_min;             /* RTC + 0x1e */
  61         u8 int_sec;             /* RTC + 0x1f */
  62
  63         /*
  64          * target_time:
  65          *      intended to be used for hibernation but hibernation
  66          *      does not work on silicon rev 1.5 so use it for non-volatile
  67          *      storage of offset between the actual_time register and linux
  68          *      time
  69          */
  70         u32 target_time;        /* RTC + 0x20 */
  71         /*
  72          * actual_time:
  73          *      readonly time since VBAT_RTC was last connected
  74          */
  75         u32 actual_time;        /* RTC + 0x24 */
  76         u32 keep_alive;         /* RTC + 0x28 */
  77 };
  78
  79 struct mpc5121_rtc_data {
  80         unsigned irq;
  81         unsigned irq_periodic;
  82         struct mpc5121_rtc_regs __iomem *regs;
  83         struct rtc_device *rtc;
  84         struct rtc_wkalrm wkalarm;
  85 };
  86
  87 /*
  88  * Update second/minute/hour registers.
  89  *
  90  * This is just so alarm will work.
  91  */
  92 static void mpc5121_rtc_update_smh(struct mpc5121_rtc_regs __iomem *regs,
  93                                    struct rtc_time *tm)
  94 {
  95         out_8(&regs->second_set, tm->tm_sec);
  96         out_8(&regs->minute_set, tm->tm_min);
  97         out_8(&regs->hour_set, tm->tm_hour);
  98
  99         /* set time sequence */
 100         out_8(&regs->set_time, 0x1);
 101         out_8(&regs->set_time, 0x3);
 102         out_8(&regs->set_time, 0x1);
 103         out_8(&regs->set_time, 0x0);
 104 }
 105
 106 static int mpc5121_rtc_read_time(struct device *dev, struct rtc_time *tm)
 107 {
 108         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 109         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 110         unsigned long now;
 111
 112         /*
 113          * linux time is actual_time plus the offset saved in target_time
 114          */
 115         now = in_be32(&regs->actual_time) + in_be32(&regs->target_time);
 116
 117         rtc_time_to_tm(now, tm);
 118
 119         /*
 120          * update second minute hour registers
 121          * so alarms will work
 122          */
 123         mpc5121_rtc_update_smh(regs, tm);
 124
 125         return rtc_valid_tm(tm);
 126 }
 127
 128 static int mpc5121_rtc_set_time(struct device *dev, struct rtc_time *tm)
 129 {
 130         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 131         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 132         int ret;
 133         unsigned long now;
 134
 135         /*
 136          * The actual_time register is read only so we write the offset
 137          * between it and linux time to the target_time register.
 138          */
 139         ret = rtc_tm_to_time(tm, &now);
 140         if (ret == 0)
 141                 out_be32(&regs->target_time, now - in_be32(&regs->actual_time));
 142
 143         /*
 144          * update second minute hour registers
 145          * so alarms will work
 146          */
 147         mpc5121_rtc_update_smh(regs, tm);
 148
 149         return 0;
 150 }
 151
 152 static int mpc5200_rtc_read_time(struct device *dev, struct rtc_time *tm)
 153 {
 154         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 155         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 156         int tmp;
 157
 158         tm->tm_sec = in_8(&regs->second);
 159         tm->tm_min = in_8(&regs->minute);
 160
 161         /* 12 hour format? */
 162         if (in_8(&regs->hour) & 0x20)
 163                 tm->tm_hour = (in_8(&regs->hour) >> 1) +
 164                         (in_8(&regs->hour) & 1 ? 12 : 0);
 165         else
 166                 tm->tm_hour = in_8(&regs->hour);
 167
 168         tmp = in_8(&regs->wday_mday);
 169         tm->tm_mday = tmp & 0x1f;
 170         tm->tm_mon = in_8(&regs->month) - 1;
 171         tm->tm_year = in_be16(&regs->year) - 1900;
 172         tm->tm_wday = (tmp >> 5) % 7;
 173         tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
 174         tm->tm_isdst = 0;
 175
 176         return 0;
 177 }
 178
 179 static int mpc5200_rtc_set_time(struct device *dev, struct rtc_time *tm)
 180 {
 181         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 182         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 183
 184         mpc5121_rtc_update_smh(regs, tm);
 185
 186         /* date */
 187         out_8(&regs->month_set, tm->tm_mon + 1);
 188         out_8(&regs->weekday_set, tm->tm_wday ? tm->tm_wday : 7);
 189         out_8(&regs->date_set, tm->tm_mday);
 190         out_be16(&regs->year_set, tm->tm_year + 1900);
 191
 192         /* set date sequence */
 193         out_8(&regs->set_date, 0x1);
 194         out_8(&regs->set_date, 0x3);
 195         out_8(&regs->set_date, 0x1);
 196         out_8(&regs->set_date, 0x0);
 197
 198         return 0;
 199 }
 200
 201 static int mpc5121_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 202 {
 203         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 204         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 205
 206         *alarm = rtc->wkalarm;
 207
 208         alarm->pending = in_8(&regs->alm_status);
 209
 210         return 0;
 211 }
 212
 213 static int mpc5121_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 214 {
 215         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 216         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 217
 218         /*
 219          * the alarm has no seconds so deal with it
 220          */
 221         if (alarm->time.tm_sec) {
 222                 alarm->time.tm_sec = 0;
 223                 alarm->time.tm_min++;
 224                 if (alarm->time.tm_min >= 60) {
 225                         alarm->time.tm_min = 0;
 226                         alarm->time.tm_hour++;
 227                         if (alarm->time.tm_hour >= 24)
 228                                 alarm->time.tm_hour = 0;
 229                 }
 230         }
 231
 232         alarm->time.tm_mday = -1;
 233         alarm->time.tm_mon = -1;
 234         alarm->time.tm_year = -1;
 235
 236         out_8(&regs->alm_min_set, alarm->time.tm_min);
 237         out_8(&regs->alm_hour_set, alarm->time.tm_hour);
 238
 239         out_8(&regs->alm_enable, alarm->enabled);
 240
 241         rtc->wkalarm = *alarm;
 242         return 0;
 243 }
 244
 245 static irqreturn_t mpc5121_rtc_handler(int irq, void *dev)
 246 {
 247         struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
 248         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 249
 250         if (in_8(&regs->int_alm)) {
 251                 /* acknowledge and clear status */
 252                 out_8(&regs->int_alm, 1);
 253                 out_8(&regs->alm_status, 1);
 254
 255                 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
 256                 return IRQ_HANDLED;
 257         }
 258
 259         return IRQ_NONE;
 260 }
 261
 262 static irqreturn_t mpc5121_rtc_handler_upd(int irq, void *dev)
 263 {
 264         struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
 265         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 266
 267         if (in_8(&regs->int_sec) && (in_8(&regs->int_enable) & 0x1)) {
 268                 /* acknowledge */
 269                 out_8(&regs->int_sec, 1);
 270
 271                 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_UF);
 272                 return IRQ_HANDLED;
 273         }
 274
 275         return IRQ_NONE;
 276 }
 277
 278 static int mpc5121_rtc_alarm_irq_enable(struct device *dev,
 279                                         unsigned int enabled)
 280 {
 281         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 282         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 283         int val;
 284
 285         if (enabled)
 286                 val = 1;
 287         else
 288                 val = 0;
 289
 290         out_8(&regs->alm_enable, val);
 291         rtc->wkalarm.enabled = val;
 292
 293         return 0;
 294 }
 295
 296 static const struct rtc_class_ops mpc5121_rtc_ops = {
 297         .read_time = mpc5121_rtc_read_time,
 298         .set_time = mpc5121_rtc_set_time,
 299         .read_alarm = mpc5121_rtc_read_alarm,
 300         .set_alarm = mpc5121_rtc_set_alarm,
 301         .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
 302 };
 303
 304 static const struct rtc_class_ops mpc5200_rtc_ops = {
 305         .read_time = mpc5200_rtc_read_time,
 306         .set_time = mpc5200_rtc_set_time,
 307         .read_alarm = mpc5121_rtc_read_alarm,
 308         .set_alarm = mpc5121_rtc_set_alarm,
 309         .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
 310 };
 311
 312 static int mpc5121_rtc_probe(struct platform_device *op)
 313 {
 314         struct mpc5121_rtc_data *rtc;
 315         int err = 0;
 316
 317         rtc = devm_kzalloc(&op->dev, sizeof(*rtc), GFP_KERNEL);
 318         if (!rtc)
 319                 return -ENOMEM;
 320
 321         rtc->regs = of_iomap(op->dev.of_node, 0);
 322         if (!rtc->regs) {
 323                 dev_err(&op->dev, "%s: couldn't map io space\n", __func__);
 324                 return -ENOSYS;
 325         }
 326
 327         device_init_wakeup(&op->dev, 1);
 328
 329         platform_set_drvdata(op, rtc);
 330
 331         rtc->irq = irq_of_parse_and_map(op->dev.of_node, 1);
 332         err = request_irq(rtc->irq, mpc5121_rtc_handler, 0,
 333                                                 "mpc5121-rtc", &op->dev);
 334         if (err) {
 335                 dev_err(&op->dev, "%s: could not request irq: %i\n",
 336                                                         __func__, rtc->irq);
 337                 goto out_dispose;
 338         }
 339
 340         rtc->irq_periodic = irq_of_parse_and_map(op->dev.of_node, 0);
 341         err = request_irq(rtc->irq_periodic, mpc5121_rtc_handler_upd,
 342                                 0, "mpc5121-rtc_upd", &op->dev);
 343         if (err) {
 344                 dev_err(&op->dev, "%s: could not request irq: %i\n",
 345                                                 __func__, rtc->irq_periodic);
 346                 goto out_dispose2;
 347         }
 348
 349         if (of_device_is_compatible(op->dev.of_node, "fsl,mpc5121-rtc")) {
 350                 u32 ka;
 351                 ka = in_be32(&rtc->regs->keep_alive);
 352                 if (ka & 0x02) {
 353                         dev_warn(&op->dev,
 354                                 "mpc5121-rtc: Battery or oscillator failure!\n");
 355                         out_be32(&rtc->regs->keep_alive, ka);
 356                 }
 357
 358                 rtc->rtc = devm_rtc_device_register(&op->dev, "mpc5121-rtc",
 359                                                 &mpc5121_rtc_ops, THIS_MODULE);
 360         } else {
 361                 rtc->rtc = devm_rtc_device_register(&op->dev, "mpc5200-rtc",
 362                                                 &mpc5200_rtc_ops, THIS_MODULE);
 363         }
 364
 365         if (IS_ERR(rtc->rtc)) {
 366                 err = PTR_ERR(rtc->rtc);
 367                 goto out_free_irq;
 368         }
 369         rtc->rtc->uie_unsupported = 1;
 370
 371         return 0;
 372
 373 out_free_irq:
 374         free_irq(rtc->irq_periodic, &op->dev);
 375 out_dispose2:
 376         irq_dispose_mapping(rtc->irq_periodic);
 377         free_irq(rtc->irq, &op->dev);
 378 out_dispose:
 379         irq_dispose_mapping(rtc->irq);
 380         iounmap(rtc->regs);
 381
 382         return err;
 383 }
 384
 385 static int mpc5121_rtc_remove(struct platform_device *op)
 386 {
 387         struct mpc5121_rtc_data *rtc = platform_get_drvdata(op);
 388         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 389
 390         /* disable interrupt, so there are no nasty surprises */
 391         out_8(&regs->alm_enable, 0);
 392         out_8(&regs->int_enable, in_8(&regs->int_enable) & ~0x1);
 393
 394         iounmap(rtc->regs);
 395         free_irq(rtc->irq, &op->dev);
 396         free_irq(rtc->irq_periodic, &op->dev);
 397         irq_dispose_mapping(rtc->irq);
 398         irq_dispose_mapping(rtc->irq_periodic);
 399
 400         return 0;
 401 }
 402
 403 #ifdef CONFIG_OF
 404 static struct of_device_id mpc5121_rtc_match[] = {
 405         { .compatible = "fsl,mpc5121-rtc", },
 406         { .compatible = "fsl,mpc5200-rtc", },
 407         {},
 408 };
 409 #endif
 410
 411 static struct platform_driver mpc5121_rtc_driver = {
 412         .driver = {
 413                 .name = "mpc5121-rtc",
 414                 .owner = THIS_MODULE,
 415                 .of_match_table = of_match_ptr(mpc5121_rtc_match),
 416         },
 417         .probe = mpc5121_rtc_probe,
 418         .remove = mpc5121_rtc_remove,
 419 };
 420
 421 module_platform_driver(mpc5121_rtc_driver);
 422
 423 MODULE_LICENSE("GPL");
 424 MODULE_AUTHOR("John Rigby <jcrigby@gmail.com>");