linux/drivers/rtc/rtc-mv.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Driver for the RTC in Marvell SoCs.
   4 */
   5
   6#include <linux/init.h>
   7#include <linux/kernel.h>
   8#include <linux/rtc.h>
   9#include <linux/bcd.h>
  10#include <linux/bitops.h>
  11#include <linux/io.h>
  12#include <linux/platform_device.h>
  13#include <linux/of.h>
  14#include <linux/delay.h>
  15#include <linux/clk.h>
  16#include <linux/gfp.h>
  17#include <linux/module.h>
  18
  19
  20#define RTC_TIME_REG_OFFS       0
  21#define RTC_SECONDS_OFFS        0
  22#define RTC_MINUTES_OFFS        8
  23#define RTC_HOURS_OFFS          16
  24#define RTC_WDAY_OFFS           24
  25#define RTC_HOURS_12H_MODE      BIT(22) /* 12 hour mode */
  26
  27#define RTC_DATE_REG_OFFS       4
  28#define RTC_MDAY_OFFS           0
  29#define RTC_MONTH_OFFS          8
  30#define RTC_YEAR_OFFS           16
  31
  32#define RTC_ALARM_TIME_REG_OFFS 8
  33#define RTC_ALARM_DATE_REG_OFFS 0xc
  34#define RTC_ALARM_VALID         BIT(7)
  35
  36#define RTC_ALARM_INTERRUPT_MASK_REG_OFFS       0x10
  37#define RTC_ALARM_INTERRUPT_CASUE_REG_OFFS      0x14
  38
  39struct rtc_plat_data {
  40        struct rtc_device *rtc;
  41        void __iomem *ioaddr;
  42        int             irq;
  43        struct clk      *clk;
  44};
  45
  46static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm)
  47{
  48        struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  49        void __iomem *ioaddr = pdata->ioaddr;
  50        u32     rtc_reg;
  51
  52        rtc_reg = (bin2bcd(tm->tm_sec) << RTC_SECONDS_OFFS) |
  53                (bin2bcd(tm->tm_min) << RTC_MINUTES_OFFS) |
  54                (bin2bcd(tm->tm_hour) << RTC_HOURS_OFFS) |
  55                (bin2bcd(tm->tm_wday) << RTC_WDAY_OFFS);
  56        writel(rtc_reg, ioaddr + RTC_TIME_REG_OFFS);
  57
  58        rtc_reg = (bin2bcd(tm->tm_mday) << RTC_MDAY_OFFS) |
  59                (bin2bcd(tm->tm_mon + 1) << RTC_MONTH_OFFS) |
  60                (bin2bcd(tm->tm_year - 100) << RTC_YEAR_OFFS);
  61        writel(rtc_reg, ioaddr + RTC_DATE_REG_OFFS);
  62
  63        return 0;
  64}
  65
  66static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm)
  67{
  68        struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  69        void __iomem *ioaddr = pdata->ioaddr;
  70        u32     rtc_time, rtc_date;
  71        unsigned int year, month, day, hour, minute, second, wday;
  72
  73        rtc_time = readl(ioaddr + RTC_TIME_REG_OFFS);
  74        rtc_date = readl(ioaddr + RTC_DATE_REG_OFFS);
  75
  76        second = rtc_time & 0x7f;
  77        minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
  78        hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hour mode */
  79        wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
  80
  81        day = rtc_date & 0x3f;
  82        month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
  83        year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
  84
  85        tm->tm_sec = bcd2bin(second);
  86        tm->tm_min = bcd2bin(minute);
  87        tm->tm_hour = bcd2bin(hour);
  88        tm->tm_mday = bcd2bin(day);
  89        tm->tm_wday = bcd2bin(wday);
  90        tm->tm_mon = bcd2bin(month) - 1;
  91        /* hw counts from year 2000, but tm_year is relative to 1900 */
  92        tm->tm_year = bcd2bin(year) + 100;
  93
  94        return 0;
  95}
  96
  97static int mv_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
  98{
  99        struct rtc_plat_data *pdata = dev_get_drvdata(dev);
 100        void __iomem *ioaddr = pdata->ioaddr;
 101        u32     rtc_time, rtc_date;
 102        unsigned int year, month, day, hour, minute, second, wday;
 103
 104        rtc_time = readl(ioaddr + RTC_ALARM_TIME_REG_OFFS);
 105        rtc_date = readl(ioaddr + RTC_ALARM_DATE_REG_OFFS);
 106
 107        second = rtc_time & 0x7f;
 108        minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
 109        hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hour mode */
 110        wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
 111
 112        day = rtc_date & 0x3f;
 113        month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
 114        year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
 115
 116        alm->time.tm_sec = bcd2bin(second);
 117        alm->time.tm_min = bcd2bin(minute);
 118        alm->time.tm_hour = bcd2bin(hour);
 119        alm->time.tm_mday = bcd2bin(day);
 120        alm->time.tm_wday = bcd2bin(wday);
 121        alm->time.tm_mon = bcd2bin(month) - 1;
 122        /* hw counts from year 2000, but tm_year is relative to 1900 */
 123        alm->time.tm_year = bcd2bin(year) + 100;
 124
 125        alm->enabled = !!readl(ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 126
 127        return rtc_valid_tm(&alm->time);
 128}
 129
 130static int mv_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 131{
 132        struct rtc_plat_data *pdata = dev_get_drvdata(dev);
 133        void __iomem *ioaddr = pdata->ioaddr;
 134        u32 rtc_reg = 0;
 135
 136        if (alm->time.tm_sec >= 0)
 137                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_sec))
 138                        << RTC_SECONDS_OFFS;
 139        if (alm->time.tm_min >= 0)
 140                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_min))
 141                        << RTC_MINUTES_OFFS;
 142        if (alm->time.tm_hour >= 0)
 143                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_hour))
 144                        << RTC_HOURS_OFFS;
 145
 146        writel(rtc_reg, ioaddr + RTC_ALARM_TIME_REG_OFFS);
 147
 148        if (alm->time.tm_mday >= 0)
 149                rtc_reg = (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mday))
 150                        << RTC_MDAY_OFFS;
 151        else
 152                rtc_reg = 0;
 153
 154        if (alm->time.tm_mon >= 0)
 155                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mon + 1))
 156                        << RTC_MONTH_OFFS;
 157
 158        if (alm->time.tm_year >= 0)
 159                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_year - 100))
 160                        << RTC_YEAR_OFFS;
 161
 162        writel(rtc_reg, ioaddr + RTC_ALARM_DATE_REG_OFFS);
 163        writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
 164        writel(alm->enabled ? 1 : 0,
 165               ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 166
 167        return 0;
 168}
 169
 170static int mv_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 171{
 172        struct rtc_plat_data *pdata = dev_get_drvdata(dev);
 173        void __iomem *ioaddr = pdata->ioaddr;
 174
 175        if (pdata->irq < 0)
 176                return -EINVAL; /* fall back into rtc-dev's emulation */
 177
 178        if (enabled)
 179                writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 180        else
 181                writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 182        return 0;
 183}
 184
 185static irqreturn_t mv_rtc_interrupt(int irq, void *data)
 186{
 187        struct rtc_plat_data *pdata = data;
 188        void __iomem *ioaddr = pdata->ioaddr;
 189
 190        /* alarm irq? */
 191        if (!readl(ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS))
 192                return IRQ_NONE;
 193
 194        /* clear interrupt */
 195        writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
 196        rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF);
 197        return IRQ_HANDLED;
 198}
 199
 200static const struct rtc_class_ops mv_rtc_ops = {
 201        .read_time      = mv_rtc_read_time,
 202        .set_time       = mv_rtc_set_time,
 203        .read_alarm     = mv_rtc_read_alarm,
 204        .set_alarm      = mv_rtc_set_alarm,
 205        .alarm_irq_enable = mv_rtc_alarm_irq_enable,
 206};
 207
 208static int __init mv_rtc_probe(struct platform_device *pdev)
 209{
 210        struct rtc_plat_data *pdata;
 211        u32 rtc_time;
 212        int ret = 0;
 213
 214        pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 215        if (!pdata)
 216                return -ENOMEM;
 217
 218        pdata->ioaddr = devm_platform_ioremap_resource(pdev, 0);
 219        if (IS_ERR(pdata->ioaddr))
 220                return PTR_ERR(pdata->ioaddr);
 221
 222        pdata->clk = devm_clk_get(&pdev->dev, NULL);
 223        /* Not all SoCs require a clock.*/
 224        if (!IS_ERR(pdata->clk))
 225                clk_prepare_enable(pdata->clk);
 226
 227        /* make sure the 24 hour mode is enabled */
 228        rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
 229        if (rtc_time & RTC_HOURS_12H_MODE) {
 230                dev_err(&pdev->dev, "12 Hour mode is enabled but not supported.\n");
 231                ret = -EINVAL;
 232                goto out;
 233        }
 234
 235        /* make sure it is actually functional */
 236        if (rtc_time == 0x01000000) {
 237                ssleep(1);
 238                rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
 239                if (rtc_time == 0x01000000) {
 240                        dev_err(&pdev->dev, "internal RTC not ticking\n");
 241                        ret = -ENODEV;
 242                        goto out;
 243                }
 244        }
 245
 246        pdata->irq = platform_get_irq(pdev, 0);
 247
 248        platform_set_drvdata(pdev, pdata);
 249
 250        pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
 251        if (IS_ERR(pdata->rtc)) {
 252                ret = PTR_ERR(pdata->rtc);
 253                goto out;
 254        }
 255
 256        if (pdata->irq >= 0) {
 257                writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 258                if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt,
 259                                     IRQF_SHARED,
 260                                     pdev->name, pdata) < 0) {
 261                        dev_warn(&pdev->dev, "interrupt not available.\n");
 262                        pdata->irq = -1;
 263                }
 264        }
 265
 266        if (pdata->irq >= 0)
 267                device_init_wakeup(&pdev->dev, 1);
 268        else
 269                clear_bit(RTC_FEATURE_ALARM, pdata->rtc->features);
 270
 271        pdata->rtc->ops = &mv_rtc_ops;
 272        pdata->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 273        pdata->rtc->range_max = RTC_TIMESTAMP_END_2099;
 274
 275        ret = devm_rtc_register_device(pdata->rtc);
 276        if (!ret)
 277                return 0;
 278out:
 279        if (!IS_ERR(pdata->clk))
 280                clk_disable_unprepare(pdata->clk);
 281
 282        return ret;
 283}
 284
 285static int __exit mv_rtc_remove(struct platform_device *pdev)
 286{
 287        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 288
 289        if (pdata->irq >= 0)
 290                device_init_wakeup(&pdev->dev, 0);
 291
 292        if (!IS_ERR(pdata->clk))
 293                clk_disable_unprepare(pdata->clk);
 294
 295        return 0;
 296}
 297
 298#ifdef CONFIG_OF
 299static const struct of_device_id rtc_mv_of_match_table[] = {
 300        { .compatible = "marvell,orion-rtc", },
 301        {}
 302};
 303MODULE_DEVICE_TABLE(of, rtc_mv_of_match_table);
 304#endif
 305
 306static struct platform_driver mv_rtc_driver = {
 307        .remove         = __exit_p(mv_rtc_remove),
 308        .driver         = {
 309                .name   = "rtc-mv",
 310                .of_match_table = of_match_ptr(rtc_mv_of_match_table),
 311        },
 312};
 313
 314module_platform_driver_probe(mv_rtc_driver, mv_rtc_probe);
 315
 316MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
 317MODULE_DESCRIPTION("Marvell RTC driver");
 318MODULE_LICENSE("GPL");
 319MODULE_ALIAS("platform:rtc-mv");
 320