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/gfp.h>
  18#include <linux/module.h>
  19
  20
  21#define RTC_TIME_REG_OFFS       0
  22#define RTC_SECONDS_OFFS        0
  23#define RTC_MINUTES_OFFS        8
  24#define RTC_HOURS_OFFS          16
  25#define RTC_WDAY_OFFS           24
  26#define RTC_HOURS_12H_MODE              (1 << 22) /* 12 hours mode */
  27
  28#define RTC_DATE_REG_OFFS       4
  29#define RTC_MDAY_OFFS           0
  30#define RTC_MONTH_OFFS          8
  31#define RTC_YEAR_OFFS           16
  32
  33#define RTC_ALARM_TIME_REG_OFFS 8
  34#define RTC_ALARM_DATE_REG_OFFS 0xc
  35#define RTC_ALARM_VALID         (1 << 7)
  36
  37#define RTC_ALARM_INTERRUPT_MASK_REG_OFFS       0x10
  38#define RTC_ALARM_INTERRUPT_CASUE_REG_OFFS      0x14
  39
  40struct rtc_plat_data {
  41        struct rtc_device *rtc;
  42        void __iomem *ioaddr;
  43        int             irq;
  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 hours 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 rtc_valid_tm(tm);
  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 hours 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        if (rtc_valid_tm(&alm->time) < 0) {
 126                dev_err(dev, "retrieved alarm date/time is not valid.\n");
 127                rtc_time_to_tm(0, &alm->time);
 128        }
 129
 130        alm->enabled = !!readl(ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 131        return 0;
 132}
 133
 134static int mv_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 135{
 136        struct rtc_plat_data *pdata = dev_get_drvdata(dev);
 137        void __iomem *ioaddr = pdata->ioaddr;
 138        u32 rtc_reg = 0;
 139
 140        if (alm->time.tm_sec >= 0)
 141                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_sec))
 142                        << RTC_SECONDS_OFFS;
 143        if (alm->time.tm_min >= 0)
 144                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_min))
 145                        << RTC_MINUTES_OFFS;
 146        if (alm->time.tm_hour >= 0)
 147                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_hour))
 148                        << RTC_HOURS_OFFS;
 149
 150        writel(rtc_reg, ioaddr + RTC_ALARM_TIME_REG_OFFS);
 151
 152        if (alm->time.tm_mday >= 0)
 153                rtc_reg = (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mday))
 154                        << RTC_MDAY_OFFS;
 155        else
 156                rtc_reg = 0;
 157
 158        if (alm->time.tm_mon >= 0)
 159                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mon + 1))
 160                        << RTC_MONTH_OFFS;
 161
 162        if (alm->time.tm_year >= 0)
 163                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_year % 100))
 164                        << RTC_YEAR_OFFS;
 165
 166        writel(rtc_reg, ioaddr + RTC_ALARM_DATE_REG_OFFS);
 167        writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
 168        writel(alm->enabled ? 1 : 0,
 169               ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 170
 171        return 0;
 172}
 173
 174static int mv_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 175{
 176        struct platform_device *pdev = to_platform_device(dev);
 177        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 178        void __iomem *ioaddr = pdata->ioaddr;
 179
 180        if (pdata->irq < 0)
 181                return -EINVAL; /* fall back into rtc-dev's emulation */
 182
 183        if (enabled)
 184                writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 185        else
 186                writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 187        return 0;
 188}
 189
 190static irqreturn_t mv_rtc_interrupt(int irq, void *data)
 191{
 192        struct rtc_plat_data *pdata = data;
 193        void __iomem *ioaddr = pdata->ioaddr;
 194
 195        /* alarm irq? */
 196        if (!readl(ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS))
 197                return IRQ_NONE;
 198
 199        /* clear interrupt */
 200        writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
 201        rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF);
 202        return IRQ_HANDLED;
 203}
 204
 205static const struct rtc_class_ops mv_rtc_ops = {
 206        .read_time      = mv_rtc_read_time,
 207        .set_time       = mv_rtc_set_time,
 208};
 209
 210static const struct rtc_class_ops mv_rtc_alarm_ops = {
 211        .read_time      = mv_rtc_read_time,
 212        .set_time       = mv_rtc_set_time,
 213        .read_alarm     = mv_rtc_read_alarm,
 214        .set_alarm      = mv_rtc_set_alarm,
 215        .alarm_irq_enable = mv_rtc_alarm_irq_enable,
 216};
 217
 218static int __devinit mv_rtc_probe(struct platform_device *pdev)
 219{
 220        struct resource *res;
 221        struct rtc_plat_data *pdata;
 222        resource_size_t size;
 223        u32 rtc_time;
 224
 225        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 226        if (!res)
 227                return -ENODEV;
 228
 229        pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 230        if (!pdata)
 231                return -ENOMEM;
 232
 233        size = resource_size(res);
 234        if (!devm_request_mem_region(&pdev->dev, res->start, size,
 235                                     pdev->name))
 236                return -EBUSY;
 237
 238        pdata->ioaddr = devm_ioremap(&pdev->dev, res->start, size);
 239        if (!pdata->ioaddr)
 240                return -ENOMEM;
 241
 242        /* make sure the 24 hours mode is enabled */
 243        rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
 244        if (rtc_time & RTC_HOURS_12H_MODE) {
 245                dev_err(&pdev->dev, "24 Hours mode not supported.\n");
 246                return -EINVAL;
 247        }
 248
 249        /* make sure it is actually functional */
 250        if (rtc_time == 0x01000000) {
 251                ssleep(1);
 252                rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
 253                if (rtc_time == 0x01000000) {
 254                        dev_err(&pdev->dev, "internal RTC not ticking\n");
 255                        return -ENODEV;
 256                }
 257        }
 258
 259        pdata->irq = platform_get_irq(pdev, 0);
 260
 261        platform_set_drvdata(pdev, pdata);
 262
 263        if (pdata->irq >= 0) {
 264                device_init_wakeup(&pdev->dev, 1);
 265                pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
 266                                                 &mv_rtc_alarm_ops,
 267                                                 THIS_MODULE);
 268        } else
 269                pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
 270                                                 &mv_rtc_ops, THIS_MODULE);
 271        if (IS_ERR(pdata->rtc))
 272                return PTR_ERR(pdata->rtc);
 273
 274        if (pdata->irq >= 0) {
 275                writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 276                if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt,
 277                                     IRQF_SHARED,
 278                                     pdev->name, pdata) < 0) {
 279                        dev_warn(&pdev->dev, "interrupt not available.\n");
 280                        pdata->irq = -1;
 281                }
 282        }
 283
 284        return 0;
 285}
 286
 287static int __exit mv_rtc_remove(struct platform_device *pdev)
 288{
 289        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 290
 291        if (pdata->irq >= 0)
 292                device_init_wakeup(&pdev->dev, 0);
 293
 294        rtc_device_unregister(pdata->rtc);
 295        return 0;
 296}
 297
 298#ifdef CONFIG_OF
 299static struct of_device_id rtc_mv_of_match_table[] = {
 300        { .compatible = "marvell,orion-rtc", },
 301        {}
 302};
 303#endif
 304
 305static struct platform_driver mv_rtc_driver = {
 306        .remove         = __exit_p(mv_rtc_remove),
 307        .driver         = {
 308                .name   = "rtc-mv",
 309                .owner  = THIS_MODULE,
 310                .of_match_table = of_match_ptr(rtc_mv_of_match_table),
 311        },
 312};
 313
 314static __init int mv_init(void)
 315{
 316        return platform_driver_probe(&mv_rtc_driver, mv_rtc_probe);
 317}
 318
 319static __exit void mv_exit(void)
 320{
 321        platform_driver_unregister(&mv_rtc_driver);
 322}
 323
 324module_init(mv_init);
 325module_exit(mv_exit);
 326
 327MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
 328MODULE_DESCRIPTION("Marvell RTC driver");
 329MODULE_LICENSE("GPL");
 330MODULE_ALIAS("platform:rtc-mv");
 331
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