linux/drivers/rtc/rtc-mv.c
<<
>>
Prefs
   1/*
   2 * Driver for the RTC in Marvell SoCs.
   3 *
   4 * This file is licensed under the terms of the GNU General Public
   5 * License version 2.  This program is licensed "as is" without any
   6 * warranty of any kind, whether express or implied.
   7 */
   8
   9#include <linux/init.h>
  10#include <linux/kernel.h>
  11#include <linux/rtc.h>
  12#include <linux/bcd.h>
  13#include <linux/bitops.h>
  14#include <linux/io.h>
  15#include <linux/platform_device.h>
  16#include <linux/of.h>
  17#include <linux/delay.h>
  18#include <linux/clk.h>
  19#include <linux/gfp.h>
  20#include <linux/module.h>
  21
  22
  23#define RTC_TIME_REG_OFFS       0
  24#define RTC_SECONDS_OFFS        0
  25#define RTC_MINUTES_OFFS        8
  26#define RTC_HOURS_OFFS          16
  27#define RTC_WDAY_OFFS           24
  28#define RTC_HOURS_12H_MODE      BIT(22) /* 12 hour mode */
  29
  30#define RTC_DATE_REG_OFFS       4
  31#define RTC_MDAY_OFFS           0
  32#define RTC_MONTH_OFFS          8
  33#define RTC_YEAR_OFFS           16
  34
  35#define RTC_ALARM_TIME_REG_OFFS 8
  36#define RTC_ALARM_DATE_REG_OFFS 0xc
  37#define RTC_ALARM_VALID         BIT(7)
  38
  39#define RTC_ALARM_INTERRUPT_MASK_REG_OFFS       0x10
  40#define RTC_ALARM_INTERRUPT_CASUE_REG_OFFS      0x14
  41
  42struct rtc_plat_data {
  43        struct rtc_device *rtc;
  44        void __iomem *ioaddr;
  45        int             irq;
  46        struct clk      *clk;
  47};
  48
  49static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm)
  50{
  51        struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  52        void __iomem *ioaddr = pdata->ioaddr;
  53        u32     rtc_reg;
  54
  55        rtc_reg = (bin2bcd(tm->tm_sec) << RTC_SECONDS_OFFS) |
  56                (bin2bcd(tm->tm_min) << RTC_MINUTES_OFFS) |
  57                (bin2bcd(tm->tm_hour) << RTC_HOURS_OFFS) |
  58                (bin2bcd(tm->tm_wday) << RTC_WDAY_OFFS);
  59        writel(rtc_reg, ioaddr + RTC_TIME_REG_OFFS);
  60
  61        rtc_reg = (bin2bcd(tm->tm_mday) << RTC_MDAY_OFFS) |
  62                (bin2bcd(tm->tm_mon + 1) << RTC_MONTH_OFFS) |
  63                (bin2bcd(tm->tm_year % 100) << RTC_YEAR_OFFS);
  64        writel(rtc_reg, ioaddr + RTC_DATE_REG_OFFS);
  65
  66        return 0;
  67}
  68
  69static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm)
  70{
  71        struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  72        void __iomem *ioaddr = pdata->ioaddr;
  73        u32     rtc_time, rtc_date;
  74        unsigned int year, month, day, hour, minute, second, wday;
  75
  76        rtc_time = readl(ioaddr + RTC_TIME_REG_OFFS);
  77        rtc_date = readl(ioaddr + RTC_DATE_REG_OFFS);
  78
  79        second = rtc_time & 0x7f;
  80        minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
  81        hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hour mode */
  82        wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
  83
  84        day = rtc_date & 0x3f;
  85        month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
  86        year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
  87
  88        tm->tm_sec = bcd2bin(second);
  89        tm->tm_min = bcd2bin(minute);
  90        tm->tm_hour = bcd2bin(hour);
  91        tm->tm_mday = bcd2bin(day);
  92        tm->tm_wday = bcd2bin(wday);
  93        tm->tm_mon = bcd2bin(month) - 1;
  94        /* hw counts from year 2000, but tm_year is relative to 1900 */
  95        tm->tm_year = bcd2bin(year) + 100;
  96
  97        return rtc_valid_tm(tm);
  98}
  99
 100static int mv_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 101{
 102        struct rtc_plat_data *pdata = dev_get_drvdata(dev);
 103        void __iomem *ioaddr = pdata->ioaddr;
 104        u32     rtc_time, rtc_date;
 105        unsigned int year, month, day, hour, minute, second, wday;
 106
 107        rtc_time = readl(ioaddr + RTC_ALARM_TIME_REG_OFFS);
 108        rtc_date = readl(ioaddr + RTC_ALARM_DATE_REG_OFFS);
 109
 110        second = rtc_time & 0x7f;
 111        minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
 112        hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hour mode */
 113        wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
 114
 115        day = rtc_date & 0x3f;
 116        month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
 117        year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
 118
 119        alm->time.tm_sec = bcd2bin(second);
 120        alm->time.tm_min = bcd2bin(minute);
 121        alm->time.tm_hour = bcd2bin(hour);
 122        alm->time.tm_mday = bcd2bin(day);
 123        alm->time.tm_wday = bcd2bin(wday);
 124        alm->time.tm_mon = bcd2bin(month) - 1;
 125        /* hw counts from year 2000, but tm_year is relative to 1900 */
 126        alm->time.tm_year = bcd2bin(year) + 100;
 127
 128        if (rtc_valid_tm(&alm->time) < 0) {
 129                dev_err(dev, "retrieved alarm date/time is not valid.\n");
 130                rtc_time_to_tm(0, &alm->time);
 131        }
 132
 133        alm->enabled = !!readl(ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 134        return 0;
 135}
 136
 137static int mv_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 138{
 139        struct rtc_plat_data *pdata = dev_get_drvdata(dev);
 140        void __iomem *ioaddr = pdata->ioaddr;
 141        u32 rtc_reg = 0;
 142
 143        if (alm->time.tm_sec >= 0)
 144                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_sec))
 145                        << RTC_SECONDS_OFFS;
 146        if (alm->time.tm_min >= 0)
 147                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_min))
 148                        << RTC_MINUTES_OFFS;
 149        if (alm->time.tm_hour >= 0)
 150                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_hour))
 151                        << RTC_HOURS_OFFS;
 152
 153        writel(rtc_reg, ioaddr + RTC_ALARM_TIME_REG_OFFS);
 154
 155        if (alm->time.tm_mday >= 0)
 156                rtc_reg = (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mday))
 157                        << RTC_MDAY_OFFS;
 158        else
 159                rtc_reg = 0;
 160
 161        if (alm->time.tm_mon >= 0)
 162                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mon + 1))
 163                        << RTC_MONTH_OFFS;
 164
 165        if (alm->time.tm_year >= 0)
 166                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_year % 100))
 167                        << RTC_YEAR_OFFS;
 168
 169        writel(rtc_reg, ioaddr + RTC_ALARM_DATE_REG_OFFS);
 170        writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
 171        writel(alm->enabled ? 1 : 0,
 172               ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 173
 174        return 0;
 175}
 176
 177static int mv_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 178{
 179        struct platform_device *pdev = to_platform_device(dev);
 180        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 181        void __iomem *ioaddr = pdata->ioaddr;
 182
 183        if (pdata->irq < 0)
 184                return -EINVAL; /* fall back into rtc-dev's emulation */
 185
 186        if (enabled)
 187                writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 188        else
 189                writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 190        return 0;
 191}
 192
 193static irqreturn_t mv_rtc_interrupt(int irq, void *data)
 194{
 195        struct rtc_plat_data *pdata = data;
 196        void __iomem *ioaddr = pdata->ioaddr;
 197
 198        /* alarm irq? */
 199        if (!readl(ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS))
 200                return IRQ_NONE;
 201
 202        /* clear interrupt */
 203        writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
 204        rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF);
 205        return IRQ_HANDLED;
 206}
 207
 208static const struct rtc_class_ops mv_rtc_ops = {
 209        .read_time      = mv_rtc_read_time,
 210        .set_time       = mv_rtc_set_time,
 211};
 212
 213static const struct rtc_class_ops mv_rtc_alarm_ops = {
 214        .read_time      = mv_rtc_read_time,
 215        .set_time       = mv_rtc_set_time,
 216        .read_alarm     = mv_rtc_read_alarm,
 217        .set_alarm      = mv_rtc_set_alarm,
 218        .alarm_irq_enable = mv_rtc_alarm_irq_enable,
 219};
 220
 221static int __init mv_rtc_probe(struct platform_device *pdev)
 222{
 223        struct resource *res;
 224        struct rtc_plat_data *pdata;
 225        u32 rtc_time;
 226        u32 rtc_date;
 227        int ret = 0;
 228
 229        pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 230        if (!pdata)
 231                return -ENOMEM;
 232
 233        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 234        pdata->ioaddr = devm_ioremap_resource(&pdev->dev, res);
 235        if (IS_ERR(pdata->ioaddr))
 236                return PTR_ERR(pdata->ioaddr);
 237
 238        pdata->clk = devm_clk_get(&pdev->dev, NULL);
 239        /* Not all SoCs require a clock.*/
 240        if (!IS_ERR(pdata->clk))
 241                clk_prepare_enable(pdata->clk);
 242
 243        /* make sure the 24 hour mode is enabled */
 244        rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
 245        if (rtc_time & RTC_HOURS_12H_MODE) {
 246                dev_err(&pdev->dev, "12 Hour mode is enabled but not supported.\n");
 247                ret = -EINVAL;
 248                goto out;
 249        }
 250
 251        /* make sure it is actually functional */
 252        if (rtc_time == 0x01000000) {
 253                ssleep(1);
 254                rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
 255                if (rtc_time == 0x01000000) {
 256                        dev_err(&pdev->dev, "internal RTC not ticking\n");
 257                        ret = -ENODEV;
 258                        goto out;
 259                }
 260        }
 261
 262        /*
 263         * A date after January 19th, 2038 does not fit on 32 bits and
 264         * will confuse the kernel and userspace. Reset to a sane date
 265         * (January 1st, 2013) if we're after 2038.
 266         */
 267        rtc_date = readl(pdata->ioaddr + RTC_DATE_REG_OFFS);
 268        if (bcd2bin((rtc_date >> RTC_YEAR_OFFS) & 0xff) >= 38) {
 269                dev_info(&pdev->dev, "invalid RTC date, resetting to January 1st, 2013\n");
 270                writel(0x130101, pdata->ioaddr + RTC_DATE_REG_OFFS);
 271        }
 272
 273        pdata->irq = platform_get_irq(pdev, 0);
 274
 275        platform_set_drvdata(pdev, pdata);
 276
 277        if (pdata->irq >= 0) {
 278                device_init_wakeup(&pdev->dev, 1);
 279                pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
 280                                                 &mv_rtc_alarm_ops,
 281                                                 THIS_MODULE);
 282        } else {
 283                pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
 284                                                 &mv_rtc_ops, THIS_MODULE);
 285        }
 286        if (IS_ERR(pdata->rtc)) {
 287                ret = PTR_ERR(pdata->rtc);
 288                goto out;
 289        }
 290
 291        if (pdata->irq >= 0) {
 292                writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 293                if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt,
 294                                     IRQF_SHARED,
 295                                     pdev->name, pdata) < 0) {
 296                        dev_warn(&pdev->dev, "interrupt not available.\n");
 297                        pdata->irq = -1;
 298                }
 299        }
 300
 301        return 0;
 302out:
 303        if (!IS_ERR(pdata->clk))
 304                clk_disable_unprepare(pdata->clk);
 305
 306        return ret;
 307}
 308
 309static int __exit mv_rtc_remove(struct platform_device *pdev)
 310{
 311        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 312
 313        if (pdata->irq >= 0)
 314                device_init_wakeup(&pdev->dev, 0);
 315
 316        if (!IS_ERR(pdata->clk))
 317                clk_disable_unprepare(pdata->clk);
 318
 319        return 0;
 320}
 321
 322#ifdef CONFIG_OF
 323static const struct of_device_id rtc_mv_of_match_table[] = {
 324        { .compatible = "marvell,orion-rtc", },
 325        {}
 326};
 327MODULE_DEVICE_TABLE(of, rtc_mv_of_match_table);
 328#endif
 329
 330static struct platform_driver mv_rtc_driver = {
 331        .remove         = __exit_p(mv_rtc_remove),
 332        .driver         = {
 333                .name   = "rtc-mv",
 334                .of_match_table = of_match_ptr(rtc_mv_of_match_table),
 335        },
 336};
 337
 338module_platform_driver_probe(mv_rtc_driver, mv_rtc_probe);
 339
 340MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
 341MODULE_DESCRIPTION("Marvell RTC driver");
 342MODULE_LICENSE("GPL");
 343MODULE_ALIAS("platform:rtc-mv");
 344