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_time64_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         unsigned long now;
 130
 131         /*
 132          * The actual_time register is read only so we write the offset
 133          * between it and linux time to the target_time register.
 134          */
 135         now = rtc_tm_to_time64(tm);
 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 mpc5200_rtc_read_time(struct device *dev, struct rtc_time *tm)
 148 {
 149         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 150         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 151         int tmp;
 152
 153         tm->tm_sec = in_8(&regs->second);
 154         tm->tm_min = in_8(&regs->minute);
 155
 156         /* 12 hour format? */
 157         if (in_8(&regs->hour) & 0x20)
 158                 tm->tm_hour = (in_8(&regs->hour) >> 1) +
 159                         (in_8(&regs->hour) & 1 ? 12 : 0);
 160         else
 161                 tm->tm_hour = in_8(&regs->hour);
 162
 163         tmp = in_8(&regs->wday_mday);
 164         tm->tm_mday = tmp & 0x1f;
 165         tm->tm_mon = in_8(&regs->month) - 1;
 166         tm->tm_year = in_be16(&regs->year) - 1900;
 167         tm->tm_wday = (tmp >> 5) % 7;
 168         tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
 169         tm->tm_isdst = 0;
 170
 171         return 0;
 172 }
 173
 174 static int mpc5200_rtc_set_time(struct device *dev, struct rtc_time *tm)
 175 {
 176         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 177         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 178
 179         mpc5121_rtc_update_smh(regs, tm);
 180
 181         /* date */
 182         out_8(&regs->month_set, tm->tm_mon + 1);
 183         out_8(&regs->weekday_set, tm->tm_wday ? tm->tm_wday : 7);
 184         out_8(&regs->date_set, tm->tm_mday);
 185         out_be16(&regs->year_set, tm->tm_year + 1900);
 186
 187         /* set date sequence */
 188         out_8(&regs->set_date, 0x1);
 189         out_8(&regs->set_date, 0x3);
 190         out_8(&regs->set_date, 0x1);
 191         out_8(&regs->set_date, 0x0);
 192
 193         return 0;
 194 }
 195
 196 static int mpc5121_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 197 {
 198         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 199         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 200
 201         *alarm = rtc->wkalarm;
 202
 203         alarm->pending = in_8(&regs->alm_status);
 204
 205         return 0;
 206 }
 207
 208 static int mpc5121_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 209 {
 210         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 211         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 212
 213         alarm->time.tm_mday = -1;
 214         alarm->time.tm_mon = -1;
 215         alarm->time.tm_year = -1;
 216
 217         out_8(&regs->alm_min_set, alarm->time.tm_min);
 218         out_8(&regs->alm_hour_set, alarm->time.tm_hour);
 219
 220         out_8(&regs->alm_enable, alarm->enabled);
 221
 222         rtc->wkalarm = *alarm;
 223         return 0;
 224 }
 225
 226 static irqreturn_t mpc5121_rtc_handler(int irq, void *dev)
 227 {
 228         struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
 229         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 230
 231         if (in_8(&regs->int_alm)) {
 232                 /* acknowledge and clear status */
 233                 out_8(&regs->int_alm, 1);
 234                 out_8(&regs->alm_status, 1);
 235
 236                 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
 237                 return IRQ_HANDLED;
 238         }
 239
 240         return IRQ_NONE;
 241 }
 242
 243 static irqreturn_t mpc5121_rtc_handler_upd(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_sec) && (in_8(&regs->int_enable) & 0x1)) {
 249                 /* acknowledge */
 250                 out_8(&regs->int_sec, 1);
 251
 252                 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_UF);
 253                 return IRQ_HANDLED;
 254         }
 255
 256         return IRQ_NONE;
 257 }
 258
 259 static int mpc5121_rtc_alarm_irq_enable(struct device *dev,
 260                                         unsigned int enabled)
 261 {
 262         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
 263         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 264         int val;
 265
 266         if (enabled)
 267                 val = 1;
 268         else
 269                 val = 0;
 270
 271         out_8(&regs->alm_enable, val);
 272         rtc->wkalarm.enabled = val;
 273
 274         return 0;
 275 }
 276
 277 static const struct rtc_class_ops mpc5121_rtc_ops = {
 278         .read_time = mpc5121_rtc_read_time,
 279         .set_time = mpc5121_rtc_set_time,
 280         .read_alarm = mpc5121_rtc_read_alarm,
 281         .set_alarm = mpc5121_rtc_set_alarm,
 282         .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
 283 };
 284
 285 static const struct rtc_class_ops mpc5200_rtc_ops = {
 286         .read_time = mpc5200_rtc_read_time,
 287         .set_time = mpc5200_rtc_set_time,
 288         .read_alarm = mpc5121_rtc_read_alarm,
 289         .set_alarm = mpc5121_rtc_set_alarm,
 290         .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
 291 };
 292
 293 static int mpc5121_rtc_probe(struct platform_device *op)
 294 {
 295         struct mpc5121_rtc_data *rtc;
 296         int err = 0;
 297
 298         rtc = devm_kzalloc(&op->dev, sizeof(*rtc), GFP_KERNEL);
 299         if (!rtc)
 300                 return -ENOMEM;
 301
 302         rtc->regs = devm_platform_ioremap_resource(op, 0);
 303         if (IS_ERR(rtc->regs)) {
 304                 dev_err(&op->dev, "%s: couldn't map io space\n", __func__);
 305                 return PTR_ERR(rtc->regs);
 306         }
 307
 308         device_init_wakeup(&op->dev, 1);
 309
 310         platform_set_drvdata(op, rtc);
 311
 312         rtc->irq = irq_of_parse_and_map(op->dev.of_node, 1);
 313         err = devm_request_irq(&op->dev, rtc->irq, mpc5121_rtc_handler, 0,
 314                                "mpc5121-rtc", &op->dev);
 315         if (err) {
 316                 dev_err(&op->dev, "%s: could not request irq: %i\n",
 317                                                         __func__, rtc->irq);
 318                 goto out_dispose;
 319         }
 320
 321         rtc->irq_periodic = irq_of_parse_and_map(op->dev.of_node, 0);
 322         err = devm_request_irq(&op->dev, rtc->irq_periodic,
 323                                mpc5121_rtc_handler_upd, 0, "mpc5121-rtc_upd",
 324                                &op->dev);
 325         if (err) {
 326                 dev_err(&op->dev, "%s: could not request irq: %i\n",
 327                                                 __func__, rtc->irq_periodic);
 328                 goto out_dispose2;
 329         }
 330
 331         rtc->rtc = devm_rtc_allocate_device(&op->dev);
 332         if (IS_ERR(rtc->rtc)) {
 333                 err = PTR_ERR(rtc->rtc);
 334                 goto out_dispose2;
 335         }
 336
 337         rtc->rtc->ops = &mpc5200_rtc_ops;
 338         set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->rtc->features);
 339         clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->rtc->features);
 340         rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_0000;
 341         rtc->rtc->range_max = 65733206399ULL; /* 4052-12-31 23:59:59 */
 342
 343         if (of_device_is_compatible(op->dev.of_node, "fsl,mpc5121-rtc")) {
 344                 u32 ka;
 345                 ka = in_be32(&rtc->regs->keep_alive);
 346                 if (ka & 0x02) {
 347                         dev_warn(&op->dev,
 348                                 "mpc5121-rtc: Battery or oscillator failure!\n");
 349                         out_be32(&rtc->regs->keep_alive, ka);
 350                 }
 351                 rtc->rtc->ops = &mpc5121_rtc_ops;
 352                 /*
 353                  * This is a limitation of the driver that abuses the target
 354                  * time register, the actual maximum year for the mpc5121 is
 355                  * also 4052.
 356                  */
 357                 rtc->rtc->range_min = 0;
 358                 rtc->rtc->range_max = U32_MAX;
 359         }
 360
 361         err = devm_rtc_register_device(rtc->rtc);
 362         if (err)
 363                 goto out_dispose2;
 364
 365         return 0;
 366
 367 out_dispose2:
 368         irq_dispose_mapping(rtc->irq_periodic);
 369 out_dispose:
 370         irq_dispose_mapping(rtc->irq);
 371
 372         return err;
 373 }
 374
 375 static int mpc5121_rtc_remove(struct platform_device *op)
 376 {
 377         struct mpc5121_rtc_data *rtc = platform_get_drvdata(op);
 378         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
 379
 380         /* disable interrupt, so there are no nasty surprises */
 381         out_8(&regs->alm_enable, 0);
 382         out_8(&regs->int_enable, in_8(&regs->int_enable) & ~0x1);
 383
 384         irq_dispose_mapping(rtc->irq);
 385         irq_dispose_mapping(rtc->irq_periodic);
 386
 387         return 0;
 388 }
 389
 390 #ifdef CONFIG_OF
 391 static const struct of_device_id mpc5121_rtc_match[] = {
 392         { .compatible = "fsl,mpc5121-rtc", },
 393         { .compatible = "fsl,mpc5200-rtc", },
 394         {},
 395 };
 396 MODULE_DEVICE_TABLE(of, mpc5121_rtc_match);
 397 #endif
 398
 399 static struct platform_driver mpc5121_rtc_driver = {
 400         .driver = {
 401                 .name = "mpc5121-rtc",
 402                 .of_match_table = of_match_ptr(mpc5121_rtc_match),
 403         },
 404         .probe = mpc5121_rtc_probe,
 405         .remove = mpc5121_rtc_remove,
 406 };
 407
 408 module_platform_driver(mpc5121_rtc_driver);
 409
 410 MODULE_LICENSE("GPL");
 411 MODULE_AUTHOR("John Rigby <jcrigby@gmail.com>");