linux/drivers/rtc/rtc-bd70528.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2//
   3// Copyright (C) 2018 ROHM Semiconductors
   4//
   5// RTC driver for ROHM BD71828 and BD71815 PMIC
   6
   7#include <linux/bcd.h>
   8#include <linux/mfd/rohm-bd71815.h>
   9#include <linux/mfd/rohm-bd71828.h>
  10#include <linux/module.h>
  11#include <linux/of.h>
  12#include <linux/platform_device.h>
  13#include <linux/regmap.h>
  14#include <linux/rtc.h>
  15
  16/*
  17 * On BD71828 and BD71815 the ALM0 MASK is 14 bytes after the ALM0
  18 * block start
  19 */
  20#define BD718XX_ALM_EN_OFFSET 14
  21
  22/*
  23 * We read regs RTC_SEC => RTC_YEAR
  24 * this struct is ordered according to chip registers.
  25 * Keep it u8 only (or packed) to avoid padding issues.
  26 */
  27struct bd70528_rtc_day {
  28        u8 sec;
  29        u8 min;
  30        u8 hour;
  31} __packed;
  32
  33struct bd70528_rtc_data {
  34        struct bd70528_rtc_day time;
  35        u8 week;
  36        u8 day;
  37        u8 month;
  38        u8 year;
  39} __packed;
  40
  41struct bd71828_rtc_alm {
  42        struct bd70528_rtc_data alm0;
  43        struct bd70528_rtc_data alm1;
  44        u8 alm_mask;
  45        u8 alm1_mask;
  46} __packed;
  47
  48struct bd70528_rtc {
  49        struct rohm_regmap_dev *parent;
  50        struct regmap *regmap;
  51        struct device *dev;
  52        u8 reg_time_start;
  53        u8 bd718xx_alm_block_start;
  54};
  55
  56static inline void tmday2rtc(struct rtc_time *t, struct bd70528_rtc_day *d)
  57{
  58        d->sec &= ~BD70528_MASK_RTC_SEC;
  59        d->min &= ~BD70528_MASK_RTC_MINUTE;
  60        d->hour &= ~BD70528_MASK_RTC_HOUR;
  61        d->sec |= bin2bcd(t->tm_sec);
  62        d->min |= bin2bcd(t->tm_min);
  63        d->hour |= bin2bcd(t->tm_hour);
  64}
  65
  66static inline void tm2rtc(struct rtc_time *t, struct bd70528_rtc_data *r)
  67{
  68        r->day &= ~BD70528_MASK_RTC_DAY;
  69        r->week &= ~BD70528_MASK_RTC_WEEK;
  70        r->month &= ~BD70528_MASK_RTC_MONTH;
  71        /*
  72         * PM and 24H bits are not used by Wake - thus we clear them
  73         * here and not in tmday2rtc() which is also used by wake.
  74         */
  75        r->time.hour &= ~(BD70528_MASK_RTC_HOUR_PM | BD70528_MASK_RTC_HOUR_24H);
  76
  77        tmday2rtc(t, &r->time);
  78        /*
  79         * We do always set time in 24H mode.
  80         */
  81        r->time.hour |= BD70528_MASK_RTC_HOUR_24H;
  82        r->day |= bin2bcd(t->tm_mday);
  83        r->week |= bin2bcd(t->tm_wday);
  84        r->month |= bin2bcd(t->tm_mon + 1);
  85        r->year = bin2bcd(t->tm_year - 100);
  86}
  87
  88static inline void rtc2tm(struct bd70528_rtc_data *r, struct rtc_time *t)
  89{
  90        t->tm_sec = bcd2bin(r->time.sec & BD70528_MASK_RTC_SEC);
  91        t->tm_min = bcd2bin(r->time.min & BD70528_MASK_RTC_MINUTE);
  92        t->tm_hour = bcd2bin(r->time.hour & BD70528_MASK_RTC_HOUR);
  93        /*
  94         * If RTC is in 12H mode, then bit BD70528_MASK_RTC_HOUR_PM
  95         * is not BCD value but tells whether it is AM or PM
  96         */
  97        if (!(r->time.hour & BD70528_MASK_RTC_HOUR_24H)) {
  98                t->tm_hour %= 12;
  99                if (r->time.hour & BD70528_MASK_RTC_HOUR_PM)
 100                        t->tm_hour += 12;
 101        }
 102        t->tm_mday = bcd2bin(r->day & BD70528_MASK_RTC_DAY);
 103        t->tm_mon = bcd2bin(r->month & BD70528_MASK_RTC_MONTH) - 1;
 104        t->tm_year = 100 + bcd2bin(r->year & BD70528_MASK_RTC_YEAR);
 105        t->tm_wday = bcd2bin(r->week & BD70528_MASK_RTC_WEEK);
 106}
 107
 108static int bd71828_set_alarm(struct device *dev, struct rtc_wkalrm *a)
 109{
 110        int ret;
 111        struct bd71828_rtc_alm alm;
 112        struct bd70528_rtc *r = dev_get_drvdata(dev);
 113
 114        ret = regmap_bulk_read(r->regmap, r->bd718xx_alm_block_start, &alm,
 115                               sizeof(alm));
 116        if (ret) {
 117                dev_err(dev, "Failed to read alarm regs\n");
 118                return ret;
 119        }
 120
 121        tm2rtc(&a->time, &alm.alm0);
 122
 123        if (!a->enabled)
 124                alm.alm_mask &= ~BD70528_MASK_ALM_EN;
 125        else
 126                alm.alm_mask |= BD70528_MASK_ALM_EN;
 127
 128        ret = regmap_bulk_write(r->regmap, r->bd718xx_alm_block_start, &alm,
 129                                sizeof(alm));
 130        if (ret)
 131                dev_err(dev, "Failed to set alarm time\n");
 132
 133        return ret;
 134
 135}
 136
 137static int bd71828_read_alarm(struct device *dev, struct rtc_wkalrm *a)
 138{
 139        int ret;
 140        struct bd71828_rtc_alm alm;
 141        struct bd70528_rtc *r = dev_get_drvdata(dev);
 142
 143        ret = regmap_bulk_read(r->regmap, r->bd718xx_alm_block_start, &alm,
 144                               sizeof(alm));
 145        if (ret) {
 146                dev_err(dev, "Failed to read alarm regs\n");
 147                return ret;
 148        }
 149
 150        rtc2tm(&alm.alm0, &a->time);
 151        a->time.tm_mday = -1;
 152        a->time.tm_mon = -1;
 153        a->time.tm_year = -1;
 154        a->enabled = !!(alm.alm_mask & BD70528_MASK_ALM_EN);
 155        a->pending = 0;
 156
 157        return 0;
 158}
 159
 160static int bd71828_set_time(struct device *dev, struct rtc_time *t)
 161{
 162        int ret;
 163        struct bd70528_rtc_data rtc_data;
 164        struct bd70528_rtc *r = dev_get_drvdata(dev);
 165
 166        ret = regmap_bulk_read(r->regmap, r->reg_time_start, &rtc_data,
 167                               sizeof(rtc_data));
 168        if (ret) {
 169                dev_err(dev, "Failed to read RTC time registers\n");
 170                return ret;
 171        }
 172        tm2rtc(t, &rtc_data);
 173
 174        ret = regmap_bulk_write(r->regmap, r->reg_time_start, &rtc_data,
 175                                sizeof(rtc_data));
 176        if (ret)
 177                dev_err(dev, "Failed to set RTC time\n");
 178
 179        return ret;
 180}
 181
 182static int bd70528_get_time(struct device *dev, struct rtc_time *t)
 183{
 184        struct bd70528_rtc *r = dev_get_drvdata(dev);
 185        struct bd70528_rtc_data rtc_data;
 186        int ret;
 187
 188        /* read the RTC date and time registers all at once */
 189        ret = regmap_bulk_read(r->regmap, r->reg_time_start, &rtc_data,
 190                               sizeof(rtc_data));
 191        if (ret) {
 192                dev_err(dev, "Failed to read RTC time (err %d)\n", ret);
 193                return ret;
 194        }
 195
 196        rtc2tm(&rtc_data, t);
 197
 198        return 0;
 199}
 200
 201static int bd71828_alm_enable(struct device *dev, unsigned int enabled)
 202{
 203        int ret;
 204        struct bd70528_rtc *r = dev_get_drvdata(dev);
 205        unsigned int enableval = BD70528_MASK_ALM_EN;
 206
 207        if (!enabled)
 208                enableval = 0;
 209
 210        ret = regmap_update_bits(r->regmap, r->bd718xx_alm_block_start +
 211                                 BD718XX_ALM_EN_OFFSET, BD70528_MASK_ALM_EN,
 212                                 enableval);
 213        if (ret)
 214                dev_err(dev, "Failed to change alarm state\n");
 215
 216        return ret;
 217}
 218
 219static const struct rtc_class_ops bd71828_rtc_ops = {
 220        .read_time              = bd70528_get_time,
 221        .set_time               = bd71828_set_time,
 222        .read_alarm             = bd71828_read_alarm,
 223        .set_alarm              = bd71828_set_alarm,
 224        .alarm_irq_enable       = bd71828_alm_enable,
 225};
 226
 227static irqreturn_t alm_hndlr(int irq, void *data)
 228{
 229        struct rtc_device *rtc = data;
 230
 231        rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF | RTC_PF);
 232        return IRQ_HANDLED;
 233}
 234
 235static int bd70528_probe(struct platform_device *pdev)
 236{
 237        struct bd70528_rtc *bd_rtc;
 238        const struct rtc_class_ops *rtc_ops;
 239        const char *irq_name;
 240        int ret;
 241        struct rtc_device *rtc;
 242        int irq;
 243        unsigned int hr;
 244        u8 hour_reg;
 245        enum rohm_chip_type chip = platform_get_device_id(pdev)->driver_data;
 246
 247        bd_rtc = devm_kzalloc(&pdev->dev, sizeof(*bd_rtc), GFP_KERNEL);
 248        if (!bd_rtc)
 249                return -ENOMEM;
 250
 251        bd_rtc->regmap = dev_get_regmap(pdev->dev.parent, NULL);
 252        if (!bd_rtc->regmap) {
 253                dev_err(&pdev->dev, "No regmap\n");
 254                return -EINVAL;
 255        }
 256
 257        bd_rtc->dev = &pdev->dev;
 258        rtc_ops = &bd71828_rtc_ops;
 259
 260        switch (chip) {
 261        case ROHM_CHIP_TYPE_BD71815:
 262                irq_name = "bd71815-rtc-alm-0";
 263                bd_rtc->reg_time_start = BD71815_REG_RTC_START;
 264
 265                /*
 266                 * See also BD718XX_ALM_EN_OFFSET:
 267                 * This works for BD71828 and BD71815 as they have same offset
 268                 * between ALM0 start and ALM0_MASK. If new ICs are to be
 269                 * added this requires proper check as ALM0_MASK is not located
 270                 * at the end of ALM0 block - but after all ALM blocks so if
 271                 * amount of ALMs differ the offset to enable/disable is likely
 272                 * to be incorrect and enable/disable must be given as own
 273                 * reg address here.
 274                 */
 275                bd_rtc->bd718xx_alm_block_start = BD71815_REG_RTC_ALM_START;
 276                hour_reg = BD71815_REG_HOUR;
 277                break;
 278        case ROHM_CHIP_TYPE_BD71828:
 279                irq_name = "bd71828-rtc-alm-0";
 280                bd_rtc->reg_time_start = BD71828_REG_RTC_START;
 281                bd_rtc->bd718xx_alm_block_start = BD71828_REG_RTC_ALM_START;
 282                hour_reg = BD71828_REG_RTC_HOUR;
 283                break;
 284        default:
 285                dev_err(&pdev->dev, "Unknown chip\n");
 286                return -ENOENT;
 287        }
 288
 289        irq = platform_get_irq_byname(pdev, irq_name);
 290
 291        if (irq < 0)
 292                return irq;
 293
 294        platform_set_drvdata(pdev, bd_rtc);
 295
 296        ret = regmap_read(bd_rtc->regmap, hour_reg, &hr);
 297
 298        if (ret) {
 299                dev_err(&pdev->dev, "Failed to reag RTC clock\n");
 300                return ret;
 301        }
 302
 303        if (!(hr & BD70528_MASK_RTC_HOUR_24H)) {
 304                struct rtc_time t;
 305
 306                ret = rtc_ops->read_time(&pdev->dev, &t);
 307
 308                if (!ret)
 309                        ret = rtc_ops->set_time(&pdev->dev, &t);
 310
 311                if (ret) {
 312                        dev_err(&pdev->dev,
 313                                "Setting 24H clock for RTC failed\n");
 314                        return ret;
 315                }
 316        }
 317
 318        device_set_wakeup_capable(&pdev->dev, true);
 319        device_wakeup_enable(&pdev->dev);
 320
 321        rtc = devm_rtc_allocate_device(&pdev->dev);
 322        if (IS_ERR(rtc)) {
 323                dev_err(&pdev->dev, "RTC device creation failed\n");
 324                return PTR_ERR(rtc);
 325        }
 326
 327        rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 328        rtc->range_max = RTC_TIMESTAMP_END_2099;
 329        rtc->ops = rtc_ops;
 330
 331        /* Request alarm IRQ prior to registerig the RTC */
 332        ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, &alm_hndlr,
 333                                        IRQF_ONESHOT, "bd70528-rtc", rtc);
 334        if (ret)
 335                return ret;
 336
 337        return devm_rtc_register_device(rtc);
 338}
 339
 340static const struct platform_device_id bd718x7_rtc_id[] = {
 341        { "bd71828-rtc", ROHM_CHIP_TYPE_BD71828 },
 342        { "bd71815-rtc", ROHM_CHIP_TYPE_BD71815 },
 343        { },
 344};
 345MODULE_DEVICE_TABLE(platform, bd718x7_rtc_id);
 346
 347static struct platform_driver bd70528_rtc = {
 348        .driver = {
 349                .name = "bd70528-rtc"
 350        },
 351        .probe = bd70528_probe,
 352        .id_table = bd718x7_rtc_id,
 353};
 354
 355module_platform_driver(bd70528_rtc);
 356
 357MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
 358MODULE_DESCRIPTION("ROHM BD71828 and BD71815 PMIC RTC driver");
 359MODULE_LICENSE("GPL");
 360MODULE_ALIAS("platform:bd70528-rtc");
 361