linux/drivers/rtc/rtc-mv.c
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   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/io.h>
  14#include <linux/platform_device.h>
  15#include <linux/of.h>
  16#include <linux/delay.h>
  17#include <linux/clk.h>
  18#include <linux/gfp.h>
  19#include <linux/module.h>
  20
  21
  22#define RTC_TIME_REG_OFFS       0
  23#define RTC_SECONDS_OFFS        0
  24#define RTC_MINUTES_OFFS        8
  25#define RTC_HOURS_OFFS          16
  26#define RTC_WDAY_OFFS           24
  27#define RTC_HOURS_12H_MODE              (1 << 22) /* 12 hours mode */
  28
  29#define RTC_DATE_REG_OFFS       4
  30#define RTC_MDAY_OFFS           0
  31#define RTC_MONTH_OFFS          8
  32#define RTC_YEAR_OFFS           16
  33
  34#define RTC_ALARM_TIME_REG_OFFS 8
  35#define RTC_ALARM_DATE_REG_OFFS 0xc
  36#define RTC_ALARM_VALID         (1 << 7)
  37
  38#define RTC_ALARM_INTERRUPT_MASK_REG_OFFS       0x10
  39#define RTC_ALARM_INTERRUPT_CASUE_REG_OFFS      0x14
  40
  41struct rtc_plat_data {
  42        struct rtc_device *rtc;
  43        void __iomem *ioaddr;
  44        int             irq;
  45        struct clk      *clk;
  46};
  47
  48static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm)
  49{
  50        struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  51        void __iomem *ioaddr = pdata->ioaddr;
  52        u32     rtc_reg;
  53
  54        rtc_reg = (bin2bcd(tm->tm_sec) << RTC_SECONDS_OFFS) |
  55                (bin2bcd(tm->tm_min) << RTC_MINUTES_OFFS) |
  56                (bin2bcd(tm->tm_hour) << RTC_HOURS_OFFS) |
  57                (bin2bcd(tm->tm_wday) << RTC_WDAY_OFFS);
  58        writel(rtc_reg, ioaddr + RTC_TIME_REG_OFFS);
  59
  60        rtc_reg = (bin2bcd(tm->tm_mday) << RTC_MDAY_OFFS) |
  61                (bin2bcd(tm->tm_mon + 1) << RTC_MONTH_OFFS) |
  62                (bin2bcd(tm->tm_year % 100) << RTC_YEAR_OFFS);
  63        writel(rtc_reg, ioaddr + RTC_DATE_REG_OFFS);
  64
  65        return 0;
  66}
  67
  68static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm)
  69{
  70        struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  71        void __iomem *ioaddr = pdata->ioaddr;
  72        u32     rtc_time, rtc_date;
  73        unsigned int year, month, day, hour, minute, second, wday;
  74
  75        rtc_time = readl(ioaddr + RTC_TIME_REG_OFFS);
  76        rtc_date = readl(ioaddr + RTC_DATE_REG_OFFS);
  77
  78        second = rtc_time & 0x7f;
  79        minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
  80        hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hours mode */
  81        wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
  82
  83        day = rtc_date & 0x3f;
  84        month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
  85        year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
  86
  87        tm->tm_sec = bcd2bin(second);
  88        tm->tm_min = bcd2bin(minute);
  89        tm->tm_hour = bcd2bin(hour);
  90        tm->tm_mday = bcd2bin(day);
  91        tm->tm_wday = bcd2bin(wday);
  92        tm->tm_mon = bcd2bin(month) - 1;
  93        /* hw counts from year 2000, but tm_year is relative to 1900 */
  94        tm->tm_year = bcd2bin(year) + 100;
  95
  96        return rtc_valid_tm(tm);
  97}
  98
  99static int mv_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 100{
 101        struct rtc_plat_data *pdata = dev_get_drvdata(dev);
 102        void __iomem *ioaddr = pdata->ioaddr;
 103        u32     rtc_time, rtc_date;
 104        unsigned int year, month, day, hour, minute, second, wday;
 105
 106        rtc_time = readl(ioaddr + RTC_ALARM_TIME_REG_OFFS);
 107        rtc_date = readl(ioaddr + RTC_ALARM_DATE_REG_OFFS);
 108
 109        second = rtc_time & 0x7f;
 110        minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
 111        hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hours mode */
 112        wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
 113
 114        day = rtc_date & 0x3f;
 115        month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
 116        year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
 117
 118        alm->time.tm_sec = bcd2bin(second);
 119        alm->time.tm_min = bcd2bin(minute);
 120        alm->time.tm_hour = bcd2bin(hour);
 121        alm->time.tm_mday = bcd2bin(day);
 122        alm->time.tm_wday = bcd2bin(wday);
 123        alm->time.tm_mon = bcd2bin(month) - 1;
 124        /* hw counts from year 2000, but tm_year is relative to 1900 */
 125        alm->time.tm_year = bcd2bin(year) + 100;
 126
 127        if (rtc_valid_tm(&alm->time) < 0) {
 128                dev_err(dev, "retrieved alarm date/time is not valid.\n");
 129                rtc_time_to_tm(0, &alm->time);
 130        }
 131
 132        alm->enabled = !!readl(ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 133        return 0;
 134}
 135
 136static int mv_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 137{
 138        struct rtc_plat_data *pdata = dev_get_drvdata(dev);
 139        void __iomem *ioaddr = pdata->ioaddr;
 140        u32 rtc_reg = 0;
 141
 142        if (alm->time.tm_sec >= 0)
 143                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_sec))
 144                        << RTC_SECONDS_OFFS;
 145        if (alm->time.tm_min >= 0)
 146                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_min))
 147                        << RTC_MINUTES_OFFS;
 148        if (alm->time.tm_hour >= 0)
 149                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_hour))
 150                        << RTC_HOURS_OFFS;
 151
 152        writel(rtc_reg, ioaddr + RTC_ALARM_TIME_REG_OFFS);
 153
 154        if (alm->time.tm_mday >= 0)
 155                rtc_reg = (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mday))
 156                        << RTC_MDAY_OFFS;
 157        else
 158                rtc_reg = 0;
 159
 160        if (alm->time.tm_mon >= 0)
 161                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mon + 1))
 162                        << RTC_MONTH_OFFS;
 163
 164        if (alm->time.tm_year >= 0)
 165                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_year % 100))
 166                        << RTC_YEAR_OFFS;
 167
 168        writel(rtc_reg, ioaddr + RTC_ALARM_DATE_REG_OFFS);
 169        writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
 170        writel(alm->enabled ? 1 : 0,
 171               ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 172
 173        return 0;
 174}
 175
 176static int mv_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 177{
 178        struct platform_device *pdev = to_platform_device(dev);
 179        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 180        void __iomem *ioaddr = pdata->ioaddr;
 181
 182        if (pdata->irq < 0)
 183                return -EINVAL; /* fall back into rtc-dev's emulation */
 184
 185        if (enabled)
 186                writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 187        else
 188                writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 189        return 0;
 190}
 191
 192static irqreturn_t mv_rtc_interrupt(int irq, void *data)
 193{
 194        struct rtc_plat_data *pdata = data;
 195        void __iomem *ioaddr = pdata->ioaddr;
 196
 197        /* alarm irq? */
 198        if (!readl(ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS))
 199                return IRQ_NONE;
 200
 201        /* clear interrupt */
 202        writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
 203        rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF);
 204        return IRQ_HANDLED;
 205}
 206
 207static const struct rtc_class_ops mv_rtc_ops = {
 208        .read_time      = mv_rtc_read_time,
 209        .set_time       = mv_rtc_set_time,
 210};
 211
 212static const struct rtc_class_ops mv_rtc_alarm_ops = {
 213        .read_time      = mv_rtc_read_time,
 214        .set_time       = mv_rtc_set_time,
 215        .read_alarm     = mv_rtc_read_alarm,
 216        .set_alarm      = mv_rtc_set_alarm,
 217        .alarm_irq_enable = mv_rtc_alarm_irq_enable,
 218};
 219
 220static int mv_rtc_probe(struct platform_device *pdev)
 221{
 222        struct resource *res;
 223        struct rtc_plat_data *pdata;
 224        resource_size_t size;
 225        u32 rtc_time;
 226        int ret = 0;
 227
 228        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 229        if (!res)
 230                return -ENODEV;
 231
 232        pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 233        if (!pdata)
 234                return -ENOMEM;
 235
 236        size = resource_size(res);
 237        if (!devm_request_mem_region(&pdev->dev, res->start, size,
 238                                     pdev->name))
 239                return -EBUSY;
 240
 241        pdata->ioaddr = devm_ioremap(&pdev->dev, res->start, size);
 242        if (!pdata->ioaddr)
 243                return -ENOMEM;
 244
 245        pdata->clk = devm_clk_get(&pdev->dev, NULL);
 246        /* Not all SoCs require a clock.*/
 247        if (!IS_ERR(pdata->clk))
 248                clk_prepare_enable(pdata->clk);
 249
 250        /* make sure the 24 hours mode is enabled */
 251        rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
 252        if (rtc_time & RTC_HOURS_12H_MODE) {
 253                dev_err(&pdev->dev, "24 Hours mode not supported.\n");
 254                ret = -EINVAL;
 255                goto out;
 256        }
 257
 258        /* make sure it is actually functional */
 259        if (rtc_time == 0x01000000) {
 260                ssleep(1);
 261                rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
 262                if (rtc_time == 0x01000000) {
 263                        dev_err(&pdev->dev, "internal RTC not ticking\n");
 264                        ret = -ENODEV;
 265                        goto out;
 266                }
 267        }
 268
 269        pdata->irq = platform_get_irq(pdev, 0);
 270
 271        platform_set_drvdata(pdev, pdata);
 272
 273        if (pdata->irq >= 0) {
 274                device_init_wakeup(&pdev->dev, 1);
 275                pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
 276                                                 &mv_rtc_alarm_ops,
 277                                                 THIS_MODULE);
 278        } else
 279                pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
 280                                                 &mv_rtc_ops, THIS_MODULE);
 281        if (IS_ERR(pdata->rtc)) {
 282                ret = PTR_ERR(pdata->rtc);
 283                goto out;
 284        }
 285
 286        if (pdata->irq >= 0) {
 287                writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 288                if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt,
 289                                     IRQF_SHARED,
 290                                     pdev->name, pdata) < 0) {
 291                        dev_warn(&pdev->dev, "interrupt not available.\n");
 292                        pdata->irq = -1;
 293                }
 294        }
 295
 296        return 0;
 297out:
 298        if (!IS_ERR(pdata->clk))
 299                clk_disable_unprepare(pdata->clk);
 300
 301        return ret;
 302}
 303
 304static int __exit mv_rtc_remove(struct platform_device *pdev)
 305{
 306        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 307
 308        if (pdata->irq >= 0)
 309                device_init_wakeup(&pdev->dev, 0);
 310
 311        rtc_device_unregister(pdata->rtc);
 312        if (!IS_ERR(pdata->clk))
 313                clk_disable_unprepare(pdata->clk);
 314
 315        return 0;
 316}
 317
 318#ifdef CONFIG_OF
 319static struct of_device_id rtc_mv_of_match_table[] = {
 320        { .compatible = "marvell,orion-rtc", },
 321        {}
 322};
 323#endif
 324
 325static struct platform_driver mv_rtc_driver = {
 326        .remove         = __exit_p(mv_rtc_remove),
 327        .driver         = {
 328                .name   = "rtc-mv",
 329                .owner  = THIS_MODULE,
 330                .of_match_table = of_match_ptr(rtc_mv_of_match_table),
 331        },
 332};
 333
 334static __init int mv_init(void)
 335{
 336        return platform_driver_probe(&mv_rtc_driver, mv_rtc_probe);
 337}
 338
 339static __exit void mv_exit(void)
 340{
 341        platform_driver_unregister(&mv_rtc_driver);
 342}
 343
 344module_init(mv_init);
 345module_exit(mv_exit);
 346
 347MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
 348MODULE_DESCRIPTION("Marvell RTC driver");
 349MODULE_LICENSE("GPL");
 350MODULE_ALIAS("platform:rtc-mv");
 351
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