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_device.h>
  18 #include <linux/of_platform.h>
  19 #include <linux/io.h>
  20 #include <linux/slab.h>
  21
  22 struct mpc5121_rtc_regs {
  23         u8 set_time;            /* RTC + 0x00 */
  24         u8 hour_set;            /* RTC + 0x01 */
  25         u8 minute_set;          /* RTC + 0x02 */
  26         u8 second_set;          /* RTC + 0x03 */
  27
  28         u8 set_date;            /* RTC + 0x04 */
  29         u8 month_set;           /* RTC + 0x05 */
  30         u8 weekday_set;         /* RTC + 0x06 */
  31         u8 date_set;            /* RTC + 0x07 */
  32
  33         u8 write_sw;            /* RTC + 0x08 */
  34         u8 sw_set;              /* RTC + 0x09 */
  35         u16 year_set;           /* RTC + 0x0a */
  36
  37         u8 alm_enable;          /* RTC + 0x0c */
  38         u8 alm_hour_set;        /* RTC + 0x0d */
  39         u8 alm_min_set;         /* RTC + 0x0e */
  40         u8 int_enable;          /* RTC + 0x0f */
  41
  42         u8 reserved1;
  43         u8 hour;                /* RTC + 0x11 */
  44         u8 minute;              /* RTC + 0x12 */
  45         u8 second;              /* RTC + 0x13 */
  46
  47         u8 month;               /* RTC + 0x14 */
  48         u8 wday_mday;           /* RTC + 0x15 */
  49         u16 year;               /* RTC + 0x16 */
  50
  51         u8 int_alm;             /* RTC + 0x18 */
  52         u8 int_sw;              /* RTC + 0x19 */
  53         u8 alm_status;          /* RTC + 0x1a */
  54         u8 sw_minute;           /* RTC + 0x1b */
  55
  56         u8 bus_error_1;         /* RTC + 0x1c */
  57         u8 int_day;             /* RTC + 0x1d */
  58         u8 int_min;             /* RTC + 0x1e */
  59         u8 int_sec;             /* RTC + 0x1f */
  60
  61         /*
  62          * target_time:
  63          *      intended to be used for hibernation but hibernation
  64          *      does not work on silicon rev 1.5 so use it for non-volatile
  65          *      storage of offset between the actual_time register and linux
  66          *      time
  67          */
  68         u32 target_time;        /* RTC + 0x20 */
  69         /*
  70          * actual_time:
  71          *      readonly time since VBAT_RTC was last connected
  72          */
  73         u32 actual_time;        /* RTC + 0x24 */
  74         u32 keep_alive;         /* RTC + 0x28 */
  75 };
  76
  77 struct mpc5121_rtc_data {
  78         unsigned irq;
  79         unsigned irq_periodic;
  80         struct mpc5121_rtc_regs __iomem *regs;
  81         struct rtc_device *rtc;
  82         struct rtc_wkalrm wkalarm;
  83 };
  84
  85 /*
  86  * Update second/minute/hour registers.
  87  *
  88  * This is just so alarm will work.
  89  */
  90 static void mpc5121_rtc_update_smh(struct mpc5121_rtc_regs __iomem *regs,
  91                                    struct rtc_time *tm)
  92 {
  93         out_8(&regs->second_set, tm->tm_sec);
  94         out_8(&regs->minute_set, tm->tm_min);
  95         out_8(&regs->hour_set, tm->tm_hour);
  96
  97         /* set time sequence */
  98         out_8(&regs->set_time, 0x1);
  99         out_8(&regs->set_time, 0x3);
 100         out_8(&regs->set_time, 0x1);
 101         out_8(&regs->set_time, 0x0);
 102 }
 103
 104 static int mpc5121_rtc_read_time(struct device *dev, struct rtc_time *tm)
 105 {
 106         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 107         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 108         unsigned long now;
 109
 110         /*
 111          * linux time is actual_time plus the offset saved in target_time
 112          */
 113         now = in_be32(&regs->actual_time) + in_be32(&regs->target_time);
 114
 115         rtc_time_to_tm(now, tm);
 116
 117         /*
 118          * update second minute hour registers
 119          * so alarms will work
 120          */
 121         mpc5121_rtc_update_smh(regs, tm);
 122
 123         return rtc_valid_tm(tm);
 124 }
 125
 126 static int mpc5121_rtc_set_time(struct device *dev, struct rtc_time *tm)
 127 {
 128         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 129         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 130         int ret;
 131         unsigned long now;
 132
 133         /*
 134          * The actual_time register is read only so we write the offset
 135          * between it and linux time to the target_time register.
 136          */
 137         ret = rtc_tm_to_time(tm, &now);
 138         if (ret == 0)
 139                 out_be32(&regs->target_time, now - in_be32(&regs->actual_time));
 140
 141         /*
 142          * update second minute hour registers
 143          * so alarms will work
 144          */
 145         mpc5121_rtc_update_smh(regs, tm);
 146
 147         return 0;
 148 }
 149
 150 static int mpc5200_rtc_read_time(struct device *dev, struct rtc_time *tm)
 151 {
 152         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 153         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 154         int tmp;
 155
 156         tm->tm_sec = in_8(&regs->second);
 157         tm->tm_min = in_8(&regs->minute);
 158
 159         /* 12 hour format? */
 160         if (in_8(&regs->hour) & 0x20)
 161                 tm->tm_hour = (in_8(&regs->hour) >> 1) +
 162                         (in_8(&regs->hour) & 1 ? 12 : 0);
 163         else
 164                 tm->tm_hour = in_8(&regs->hour);
 165
 166         tmp = in_8(&regs->wday_mday);
 167         tm->tm_mday = tmp & 0x1f;
 168         tm->tm_mon = in_8(&regs->month) - 1;
 169         tm->tm_year = in_be16(&regs->year) - 1900;
 170         tm->tm_wday = (tmp >> 5) % 7;
 171         tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
 172         tm->tm_isdst = 0;
 173
 174         return 0;
 175 }
 176
 177 static int mpc5200_rtc_set_time(struct device *dev, struct rtc_time *tm)
 178 {
 179         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 180         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 181
 182         mpc5121_rtc_update_smh(regs, tm);
 183
 184         /* date */
 185         out_8(&regs->month_set, tm->tm_mon + 1);
 186         out_8(&regs->weekday_set, tm->tm_wday ? tm->tm_wday : 7);
 187         out_8(&regs->date_set, tm->tm_mday);
 188         out_be16(&regs->year_set, tm->tm_year + 1900);
 189
 190         /* set date sequence */
 191         out_8(&regs->set_date, 0x1);
 192         out_8(&regs->set_date, 0x3);
 193         out_8(&regs->set_date, 0x1);
 194         out_8(&regs->set_date, 0x0);
 195
 196         return 0;
 197 }
 198
 199 static int mpc5121_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 200 {
 201         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 202         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 203
 204         *alarm = rtc->wkalarm;
 205
 206         alarm->pending = in_8(&regs->alm_status);
 207
 208         return 0;
 209 }
 210
 211 static int mpc5121_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 212 {
 213         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 214         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 215
 216         /*
 217          * the alarm has no seconds so deal with it
 218          */
 219         if (alarm->time.tm_sec) {
 220                 alarm->time.tm_sec = 0;
 221                 alarm->time.tm_min++;
 222                 if (alarm->time.tm_min >= 60) {
 223                         alarm->time.tm_min = 0;
 224                         alarm->time.tm_hour++;
 225                         if (alarm->time.tm_hour >= 24)
 226                                 alarm->time.tm_hour = 0;
 227                 }
 228         }
 229
 230         alarm->time.tm_mday = -1;
 231         alarm->time.tm_mon = -1;
 232         alarm->time.tm_year = -1;
 233
 234         out_8(&regs->alm_min_set, alarm->time.tm_min);
 235         out_8(&regs->alm_hour_set, alarm->time.tm_hour);
 236
 237         out_8(&regs->alm_enable, alarm->enabled);
 238
 239         rtc->wkalarm = *alarm;
 240         return 0;
 241 }
 242
 243 static irqreturn_t mpc5121_rtc_handler(int irq, void *dev)
 244 {
 245         struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
 246         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 247
 248         if (in_8(&regs->int_alm)) {
 249                 /* acknowledge and clear status */
 250                 out_8(&regs->int_alm, 1);
 251                 out_8(&regs->alm_status, 1);
 252
 253                 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
 254                 return IRQ_HANDLED;
 255         }
 256
 257         return IRQ_NONE;
 258 }
 259
 260 static irqreturn_t mpc5121_rtc_handler_upd(int irq, void *dev)
 261 {
 262         struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
 263         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 264
 265         if (in_8(&regs->int_sec) && (in_8(&regs->int_enable) & 0x1)) {
 266                 /* acknowledge */
 267                 out_8(&regs->int_sec, 1);
 268
 269                 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_UF);
 270                 return IRQ_HANDLED;
 271         }
 272
 273         return IRQ_NONE;
 274 }
 275
 276 static int mpc5121_rtc_alarm_irq_enable(struct device *dev,
 277                                         unsigned int enabled)
 278 {
 279         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 280         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 281         int val;
 282
 283         if (enabled)
 284                 val = 1;
 285         else
 286                 val = 0;
 287
 288         out_8(&regs->alm_enable, val);
 289         rtc->wkalarm.enabled = val;
 290
 291         return 0;
 292 }
 293
 294 static const struct rtc_class_ops mpc5121_rtc_ops = {
 295         .read_time = mpc5121_rtc_read_time,
 296         .set_time = mpc5121_rtc_set_time,
 297         .read_alarm = mpc5121_rtc_read_alarm,
 298         .set_alarm = mpc5121_rtc_set_alarm,
 299         .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
 300 };
 301
 302 static const struct rtc_class_ops mpc5200_rtc_ops = {
 303         .read_time = mpc5200_rtc_read_time,
 304         .set_time = mpc5200_rtc_set_time,
 305         .read_alarm = mpc5121_rtc_read_alarm,
 306         .set_alarm = mpc5121_rtc_set_alarm,
 307         .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
 308 };
 309
 310 static int mpc5121_rtc_probe(struct platform_device *op)
 311 {
 312         struct mpc5121_rtc_data *rtc;
 313         int err = 0;
 314
 315         rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
 316         if (!rtc)
 317                 return -ENOMEM;
 318
 319         rtc->regs = of_iomap(op->dev.of_node, 0);
 320         if (!rtc->regs) {
 321                 dev_err(&op->dev, "%s: couldn't map io space\n", __func__);
 322                 err = -ENOSYS;
 323                 goto out_free;
 324         }
 325
 326         device_init_wakeup(&op->dev, 1);
 327
 328         dev_set_drvdata(&op->dev, rtc);
 329
 330         rtc->irq = irq_of_parse_and_map(op->dev.of_node, 1);
 331         err = request_irq(rtc->irq, mpc5121_rtc_handler, 0,
 332                                                 "mpc5121-rtc", &op->dev);
 333         if (err) {
 334                 dev_err(&op->dev, "%s: could not request irq: %i\n",
 335                                                         __func__, rtc->irq);
 336                 goto out_dispose;
 337         }
 338
 339         rtc->irq_periodic = irq_of_parse_and_map(op->dev.of_node, 0);
 340         err = request_irq(rtc->irq_periodic, mpc5121_rtc_handler_upd,
 341                                 0, "mpc5121-rtc_upd", &op->dev);
 342         if (err) {
 343                 dev_err(&op->dev, "%s: could not request irq: %i\n",
 344                                                 __func__, rtc->irq_periodic);
 345                 goto out_dispose2;
 346         }
 347
 348         if (of_device_is_compatible(op->dev.of_node, "fsl,mpc5121-rtc")) {
 349                 u32 ka;
 350                 ka = in_be32(&rtc->regs->keep_alive);
 351                 if (ka & 0x02) {
 352                         dev_warn(&op->dev,
 353                                 "mpc5121-rtc: Battery or oscillator failure!\n");
 354                         out_be32(&rtc->regs->keep_alive, ka);
 355                 }
 356
 357                 rtc->rtc = rtc_device_register("mpc5121-rtc", &op->dev,
 358                                                 &mpc5121_rtc_ops, THIS_MODULE);
 359         } else {
 360                 rtc->rtc = rtc_device_register("mpc5200-rtc", &op->dev,
 361                                                 &mpc5200_rtc_ops, THIS_MODULE);
 362         }
 363
 364         if (IS_ERR(rtc->rtc)) {
 365                 err = PTR_ERR(rtc->rtc);
 366                 goto out_free_irq;
 367         }
 368         rtc->rtc->uie_unsupported = 1;
 369
 370         return 0;
 371
 372 out_free_irq:
 373         free_irq(rtc->irq_periodic, &op->dev);
 374 out_dispose2:
 375         irq_dispose_mapping(rtc->irq_periodic);
 376         free_irq(rtc->irq, &op->dev);
 377 out_dispose:
 378         irq_dispose_mapping(rtc->irq);
 379         iounmap(rtc->regs);
 380 out_free:
 381         kfree(rtc);
 382
 383         return err;
 384 }
 385
 386 static int mpc5121_rtc_remove(struct platform_device *op)
 387 {
 388         struct mpc5121_rtc_data *rtc = dev_get_drvdata(&op->dev);
 389         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 390
 391         /* disable interrupt, so there are no nasty surprises */
 392         out_8(&regs->alm_enable, 0);
 393         out_8(&regs->int_enable, in_8(&regs->int_enable) & ~0x1);
 394
 395         rtc_device_unregister(rtc->rtc);
 396         iounmap(rtc->regs);
 397         free_irq(rtc->irq, &op->dev);
 398         free_irq(rtc->irq_periodic, &op->dev);
 399         irq_dispose_mapping(rtc->irq);
 400         irq_dispose_mapping(rtc->irq_periodic);
 401         dev_set_drvdata(&op->dev, NULL);
 402         kfree(rtc);
 403
 404         return 0;
 405 }
 406
 407 #ifdef CONFIG_OF
 408 static struct of_device_id mpc5121_rtc_match[] = {
 409         { .compatible = "fsl,mpc5121-rtc", },
 410         { .compatible = "fsl,mpc5200-rtc", },
 411         {},
 412 };
 413 #endif
 414
 415 static struct platform_driver mpc5121_rtc_driver = {
 416         .driver = {
 417                 .name = "mpc5121-rtc",
 418                 .owner = THIS_MODULE,
 419                 .of_match_table = of_match_ptr(mpc5121_rtc_match),
 420         },
 421         .probe = mpc5121_rtc_probe,
 422         .remove = mpc5121_rtc_remove,
 423 };
 424
 425 module_platform_driver(mpc5121_rtc_driver);
 426
 427 MODULE_LICENSE("GPL");
 428 MODULE_AUTHOR("John Rigby <jcrigby@gmail.com>");