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  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/init.h>
  13 #include <linux/module.h>
  14 #include <linux/rtc.h>
  15 #include <linux/of_device.h>
  16 #include <linux/of_platform.h>
  17 #include <linux/io.h>
  18
  19 struct mpc5121_rtc_regs {
  20         u8 set_time;            /* RTC + 0x00 */
  21         u8 hour_set;            /* RTC + 0x01 */
  22         u8 minute_set;          /* RTC + 0x02 */
  23         u8 second_set;          /* RTC + 0x03 */
  24
  25         u8 set_date;            /* RTC + 0x04 */
  26         u8 month_set;           /* RTC + 0x05 */
  27         u8 weekday_set;         /* RTC + 0x06 */
  28         u8 date_set;            /* RTC + 0x07 */
  29
  30         u8 write_sw;            /* RTC + 0x08 */
  31         u8 sw_set;              /* RTC + 0x09 */
  32         u16 year_set;           /* RTC + 0x0a */
  33
  34         u8 alm_enable;          /* RTC + 0x0c */
  35         u8 alm_hour_set;        /* RTC + 0x0d */
  36         u8 alm_min_set;         /* RTC + 0x0e */
  37         u8 int_enable;          /* RTC + 0x0f */
  38
  39         u8 reserved1;
  40         u8 hour;                /* RTC + 0x11 */
  41         u8 minute;              /* RTC + 0x12 */
  42         u8 second;              /* RTC + 0x13 */
  43
  44         u8 month;               /* RTC + 0x14 */
  45         u8 wday_mday;           /* RTC + 0x15 */
  46         u16 year;               /* RTC + 0x16 */
  47
  48         u8 int_alm;             /* RTC + 0x18 */
  49         u8 int_sw;              /* RTC + 0x19 */
  50         u8 alm_status;          /* RTC + 0x1a */
  51         u8 sw_minute;           /* RTC + 0x1b */
  52
  53         u8 bus_error_1;         /* RTC + 0x1c */
  54         u8 int_day;             /* RTC + 0x1d */
  55         u8 int_min;             /* RTC + 0x1e */
  56         u8 int_sec;             /* RTC + 0x1f */
  57
  58         /*
  59          * target_time:
  60          *      intended to be used for hibernation but hibernation
  61          *      does not work on silicon rev 1.5 so use it for non-volatile
  62          *      storage of offset between the actual_time register and linux
  63          *      time
  64          */
  65         u32 target_time;        /* RTC + 0x20 */
  66         /*
  67          * actual_time:
  68          *      readonly time since VBAT_RTC was last connected
  69          */
  70         u32 actual_time;        /* RTC + 0x24 */
  71         u32 keep_alive;         /* RTC + 0x28 */
  72 };
  73
  74 struct mpc5121_rtc_data {
  75         unsigned irq;
  76         unsigned irq_periodic;
  77         struct mpc5121_rtc_regs __iomem *regs;
  78         struct rtc_device *rtc;
  79         struct rtc_wkalrm wkalarm;
  80 };
  81
  82 /*
  83  * Update second/minute/hour registers.
  84  *
  85  * This is just so alarm will work.
  86  */
  87 static void mpc5121_rtc_update_smh(struct mpc5121_rtc_regs __iomem *regs,
  88                                    struct rtc_time *tm)
  89 {
  90         out_8(&regs->second_set, tm->tm_sec);
  91         out_8(&regs->minute_set, tm->tm_min);
  92         out_8(&regs->hour_set, tm->tm_hour);
  93
  94         /* set time sequence */
  95         out_8(&regs->set_time, 0x1);
  96         out_8(&regs->set_time, 0x3);
  97         out_8(&regs->set_time, 0x1);
  98         out_8(&regs->set_time, 0x0);
  99 }
 100
 101 static int mpc5121_rtc_read_time(struct device *dev, struct rtc_time *tm)
 102 {
 103         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 104         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 105         unsigned long now;
 106
 107         /*
 108          * linux time is actual_time plus the offset saved in target_time
 109          */
 110         now = in_be32(&regs->actual_time) + in_be32(&regs->target_time);
 111
 112         rtc_time_to_tm(now, tm);
 113
 114         /*
 115          * update second minute hour registers
 116          * so alarms will work
 117          */
 118         mpc5121_rtc_update_smh(regs, tm);
 119
 120         return rtc_valid_tm(tm);
 121 }
 122
 123 static int mpc5121_rtc_set_time(struct device *dev, struct rtc_time *tm)
 124 {
 125         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 126         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 127         int ret;
 128         unsigned long now;
 129
 130         /*
 131          * The actual_time register is read only so we write the offset
 132          * between it and linux time to the target_time register.
 133          */
 134         ret = rtc_tm_to_time(tm, &now);
 135         if (ret == 0)
 136                 out_be32(&regs->target_time, now - in_be32(&regs->actual_time));
 137
 138         /*
 139          * update second minute hour registers
 140          * so alarms will work
 141          */
 142         mpc5121_rtc_update_smh(regs, tm);
 143
 144         return 0;
 145 }
 146
 147 static int mpc5121_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 148 {
 149         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 150         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 151
 152         *alarm = rtc->wkalarm;
 153
 154         alarm->pending = in_8(&regs->alm_status);
 155
 156         return 0;
 157 }
 158
 159 static int mpc5121_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 160 {
 161         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 162         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 163
 164         /*
 165          * the alarm has no seconds so deal with it
 166          */
 167         if (alarm->time.tm_sec) {
 168                 alarm->time.tm_sec = 0;
 169                 alarm->time.tm_min++;
 170                 if (alarm->time.tm_min >= 60) {
 171                         alarm->time.tm_min = 0;
 172                         alarm->time.tm_hour++;
 173                         if (alarm->time.tm_hour >= 24)
 174                                 alarm->time.tm_hour = 0;
 175                 }
 176         }
 177
 178         alarm->time.tm_mday = -1;
 179         alarm->time.tm_mon = -1;
 180         alarm->time.tm_year = -1;
 181
 182         out_8(&regs->alm_min_set, alarm->time.tm_min);
 183         out_8(&regs->alm_hour_set, alarm->time.tm_hour);
 184
 185         out_8(&regs->alm_enable, alarm->enabled);
 186
 187         rtc->wkalarm = *alarm;
 188         return 0;
 189 }
 190
 191 static irqreturn_t mpc5121_rtc_handler(int irq, void *dev)
 192 {
 193         struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
 194         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 195
 196         if (in_8(&regs->int_alm)) {
 197                 /* acknowledge and clear status */
 198                 out_8(&regs->int_alm, 1);
 199                 out_8(&regs->alm_status, 1);
 200
 201                 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
 202                 return IRQ_HANDLED;
 203         }
 204
 205         return IRQ_NONE;
 206 }
 207
 208 static irqreturn_t mpc5121_rtc_handler_upd(int irq, void *dev)
 209 {
 210         struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
 211         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 212
 213         if (in_8(&regs->int_sec) && (in_8(&regs->int_enable) & 0x1)) {
 214                 /* acknowledge */
 215                 out_8(&regs->int_sec, 1);
 216
 217                 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_UF);
 218                 return IRQ_HANDLED;
 219         }
 220
 221         return IRQ_NONE;
 222 }
 223
 224 static int mpc5121_rtc_alarm_irq_enable(struct device *dev,
 225                                         unsigned int enabled)
 226 {
 227         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 228         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 229         int val;
 230
 231         if (enabled)
 232                 val = 1;
 233         else
 234                 val = 0;
 235
 236         out_8(&regs->alm_enable, val);
 237         rtc->wkalarm.enabled = val;
 238
 239         return 0;
 240 }
 241
 242 static int mpc5121_rtc_update_irq_enable(struct device *dev,
 243                                          unsigned int enabled)
 244 {
 245         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 246         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 247         int val;
 248
 249         val = in_8(&regs->int_enable);
 250
 251         if (enabled)
 252                 val = (val & ~0x8) | 0x1;
 253         else
 254                 val &= ~0x1;
 255
 256         out_8(&regs->int_enable, val);
 257
 258         return 0;
 259 }
 260
 261 static const struct rtc_class_ops mpc5121_rtc_ops = {
 262         .read_time = mpc5121_rtc_read_time,
 263         .set_time = mpc5121_rtc_set_time,
 264         .read_alarm = mpc5121_rtc_read_alarm,
 265         .set_alarm = mpc5121_rtc_set_alarm,
 266         .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
 267         .update_irq_enable = mpc5121_rtc_update_irq_enable,
 268 };
 269
 270 static int __devinit mpc5121_rtc_probe(struct of_device *op,
 271                                         const struct of_device_id *match)
 272 {
 273         struct mpc5121_rtc_data *rtc;
 274         int err = 0;
 275         u32 ka;
 276
 277         rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
 278         if (!rtc)
 279                 return -ENOMEM;
 280
 281         rtc->regs = of_iomap(op->node, 0);
 282         if (!rtc->regs) {
 283                 dev_err(&op->dev, "%s: couldn't map io space\n", __func__);
 284                 err = -ENOSYS;
 285                 goto out_free;
 286         }
 287
 288         device_init_wakeup(&op->dev, 1);
 289
 290         dev_set_drvdata(&op->dev, rtc);
 291
 292         rtc->irq = irq_of_parse_and_map(op->node, 1);
 293         err = request_irq(rtc->irq, mpc5121_rtc_handler, IRQF_DISABLED,
 294                                                 "mpc5121-rtc", &op->dev);
 295         if (err) {
 296                 dev_err(&op->dev, "%s: could not request irq: %i\n",
 297                                                         __func__, rtc->irq);
 298                 goto out_dispose;
 299         }
 300
 301         rtc->irq_periodic = irq_of_parse_and_map(op->node, 0);
 302         err = request_irq(rtc->irq_periodic, mpc5121_rtc_handler_upd,
 303                                 IRQF_DISABLED, "mpc5121-rtc_upd", &op->dev);
 304         if (err) {
 305                 dev_err(&op->dev, "%s: could not request irq: %i\n",
 306                                                 __func__, rtc->irq_periodic);
 307                 goto out_dispose2;
 308         }
 309
 310         ka = in_be32(&rtc->regs->keep_alive);
 311         if (ka & 0x02) {
 312                 dev_warn(&op->dev,
 313                         "mpc5121-rtc: Battery or oscillator failure!\n");
 314                 out_be32(&rtc->regs->keep_alive, ka);
 315         }
 316
 317         rtc->rtc = rtc_device_register("mpc5121-rtc", &op->dev,
 318                                         &mpc5121_rtc_ops, THIS_MODULE);
 319         if (IS_ERR(rtc->rtc)) {
 320                 err = PTR_ERR(rtc->rtc);
 321                 goto out_free_irq;
 322         }
 323
 324         return 0;
 325
 326 out_free_irq:
 327         free_irq(rtc->irq_periodic, &op->dev);
 328 out_dispose2:
 329         irq_dispose_mapping(rtc->irq_periodic);
 330         free_irq(rtc->irq, &op->dev);
 331 out_dispose:
 332         irq_dispose_mapping(rtc->irq);
 333         iounmap(rtc->regs);
 334 out_free:
 335         kfree(rtc);
 336
 337         return err;
 338 }
 339
 340 static int __devexit mpc5121_rtc_remove(struct of_device *op)
 341 {
 342         struct mpc5121_rtc_data *rtc = dev_get_drvdata(&op->dev);
 343         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 344
 345         /* disable interrupt, so there are no nasty surprises */
 346         out_8(&regs->alm_enable, 0);
 347         out_8(&regs->int_enable, in_8(&regs->int_enable) & ~0x1);
 348
 349         rtc_device_unregister(rtc->rtc);
 350         iounmap(rtc->regs);
 351         free_irq(rtc->irq, &op->dev);
 352         free_irq(rtc->irq_periodic, &op->dev);
 353         irq_dispose_mapping(rtc->irq);
 354         irq_dispose_mapping(rtc->irq_periodic);
 355         dev_set_drvdata(&op->dev, NULL);
 356         kfree(rtc);
 357
 358         return 0;
 359 }
 360
 361 static struct of_device_id mpc5121_rtc_match[] __devinitdata = {
 362         { .compatible = "fsl,mpc5121-rtc", },
 363         {},
 364 };
 365
 366 static struct of_platform_driver mpc5121_rtc_driver = {
 367         .owner = THIS_MODULE,
 368         .name = "mpc5121-rtc",
 369         .match_table = mpc5121_rtc_match,
 370         .probe = mpc5121_rtc_probe,
 371         .remove = __devexit_p(mpc5121_rtc_remove),
 372 };
 373
 374 static int __init mpc5121_rtc_init(void)
 375 {
 376         return of_register_platform_driver(&mpc5121_rtc_driver);
 377 }
 378 module_init(mpc5121_rtc_init);
 379
 380 static void __exit mpc5121_rtc_exit(void)
 381 {
 382         of_unregister_platform_driver(&mpc5121_rtc_driver);
 383 }
 384 module_exit(mpc5121_rtc_exit);
 385
 386 MODULE_LICENSE("GPL");
 387 MODULE_AUTHOR("John Rigby <jcrigby@gmail.com>");