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/io.h>
  14#include <linux/platform_device.h>
  15#include <linux/delay.h>
  16#include <linux/gfp.h>
  17
  18
  19#define RTC_TIME_REG_OFFS       0
  20#define RTC_SECONDS_OFFS        0
  21#define RTC_MINUTES_OFFS        8
  22#define RTC_HOURS_OFFS          16
  23#define RTC_WDAY_OFFS           24
  24#define RTC_HOURS_12H_MODE              (1 << 22) /* 12 hours mode */
  25
  26#define RTC_DATE_REG_OFFS       4
  27#define RTC_MDAY_OFFS           0
  28#define RTC_MONTH_OFFS          8
  29#define RTC_YEAR_OFFS           16
  30
  31#define RTC_ALARM_TIME_REG_OFFS 8
  32#define RTC_ALARM_DATE_REG_OFFS 0xc
  33#define RTC_ALARM_VALID         (1 << 7)
  34
  35#define RTC_ALARM_INTERRUPT_MASK_REG_OFFS       0x10
  36#define RTC_ALARM_INTERRUPT_CASUE_REG_OFFS      0x14
  37
  38struct rtc_plat_data {
  39        struct rtc_device *rtc;
  40        void __iomem *ioaddr;
  41        int             irq;
  42};
  43
  44static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm)
  45{
  46        struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  47        void __iomem *ioaddr = pdata->ioaddr;
  48        u32     rtc_reg;
  49
  50        rtc_reg = (bin2bcd(tm->tm_sec) << RTC_SECONDS_OFFS) |
  51                (bin2bcd(tm->tm_min) << RTC_MINUTES_OFFS) |
  52                (bin2bcd(tm->tm_hour) << RTC_HOURS_OFFS) |
  53                (bin2bcd(tm->tm_wday) << RTC_WDAY_OFFS);
  54        writel(rtc_reg, ioaddr + RTC_TIME_REG_OFFS);
  55
  56        rtc_reg = (bin2bcd(tm->tm_mday) << RTC_MDAY_OFFS) |
  57                (bin2bcd(tm->tm_mon + 1) << RTC_MONTH_OFFS) |
  58                (bin2bcd(tm->tm_year % 100) << RTC_YEAR_OFFS);
  59        writel(rtc_reg, ioaddr + RTC_DATE_REG_OFFS);
  60
  61        return 0;
  62}
  63
  64static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm)
  65{
  66        struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  67        void __iomem *ioaddr = pdata->ioaddr;
  68        u32     rtc_time, rtc_date;
  69        unsigned int year, month, day, hour, minute, second, wday;
  70
  71        rtc_time = readl(ioaddr + RTC_TIME_REG_OFFS);
  72        rtc_date = readl(ioaddr + RTC_DATE_REG_OFFS);
  73
  74        second = rtc_time & 0x7f;
  75        minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
  76        hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hours mode */
  77        wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
  78
  79        day = rtc_date & 0x3f;
  80        month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
  81        year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
  82
  83        tm->tm_sec = bcd2bin(second);
  84        tm->tm_min = bcd2bin(minute);
  85        tm->tm_hour = bcd2bin(hour);
  86        tm->tm_mday = bcd2bin(day);
  87        tm->tm_wday = bcd2bin(wday);
  88        tm->tm_mon = bcd2bin(month) - 1;
  89        /* hw counts from year 2000, but tm_year is relative to 1900 */
  90        tm->tm_year = bcd2bin(year) + 100;
  91
  92        return rtc_valid_tm(tm);
  93}
  94
  95static int mv_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
  96{
  97        struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  98        void __iomem *ioaddr = pdata->ioaddr;
  99        u32     rtc_time, rtc_date;
 100        unsigned int year, month, day, hour, minute, second, wday;
 101
 102        rtc_time = readl(ioaddr + RTC_ALARM_TIME_REG_OFFS);
 103        rtc_date = readl(ioaddr + RTC_ALARM_DATE_REG_OFFS);
 104
 105        second = rtc_time & 0x7f;
 106        minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
 107        hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hours mode */
 108        wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
 109
 110        day = rtc_date & 0x3f;
 111        month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
 112        year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
 113
 114        alm->time.tm_sec = bcd2bin(second);
 115        alm->time.tm_min = bcd2bin(minute);
 116        alm->time.tm_hour = bcd2bin(hour);
 117        alm->time.tm_mday = bcd2bin(day);
 118        alm->time.tm_wday = bcd2bin(wday);
 119        alm->time.tm_mon = bcd2bin(month) - 1;
 120        /* hw counts from year 2000, but tm_year is relative to 1900 */
 121        alm->time.tm_year = bcd2bin(year) + 100;
 122
 123        if (rtc_valid_tm(&alm->time) < 0) {
 124                dev_err(dev, "retrieved alarm date/time is not valid.\n");
 125                rtc_time_to_tm(0, &alm->time);
 126        }
 127
 128        alm->enabled = !!readl(ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 129        return 0;
 130}
 131
 132static int mv_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 133{
 134        struct rtc_plat_data *pdata = dev_get_drvdata(dev);
 135        void __iomem *ioaddr = pdata->ioaddr;
 136        u32 rtc_reg = 0;
 137
 138        if (alm->time.tm_sec >= 0)
 139                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_sec))
 140                        << RTC_SECONDS_OFFS;
 141        if (alm->time.tm_min >= 0)
 142                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_min))
 143                        << RTC_MINUTES_OFFS;
 144        if (alm->time.tm_hour >= 0)
 145                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_hour))
 146                        << RTC_HOURS_OFFS;
 147
 148        writel(rtc_reg, ioaddr + RTC_ALARM_TIME_REG_OFFS);
 149
 150        if (alm->time.tm_mday >= 0)
 151                rtc_reg = (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mday))
 152                        << RTC_MDAY_OFFS;
 153        else
 154                rtc_reg = 0;
 155
 156        if (alm->time.tm_mon >= 0)
 157                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mon + 1))
 158                        << RTC_MONTH_OFFS;
 159
 160        if (alm->time.tm_year >= 0)
 161                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_year % 100))
 162                        << RTC_YEAR_OFFS;
 163
 164        writel(rtc_reg, ioaddr + RTC_ALARM_DATE_REG_OFFS);
 165        writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
 166        writel(alm->enabled ? 1 : 0,
 167               ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 168
 169        return 0;
 170}
 171
 172static int mv_rtc_ioctl(struct device *dev, unsigned int cmd,
 173                        unsigned long arg)
 174{
 175        struct platform_device *pdev = to_platform_device(dev);
 176        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 177        void __iomem *ioaddr = pdata->ioaddr;
 178
 179        if (pdata->irq < 0)
 180                return -ENOIOCTLCMD; /* fall back into rtc-dev's emulation */
 181        switch (cmd) {
 182        case RTC_AIE_OFF:
 183                writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 184                break;
 185        case RTC_AIE_ON:
 186                writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 187                break;
 188        default:
 189                return -ENOIOCTLCMD;
 190        }
 191        return 0;
 192}
 193
 194static irqreturn_t mv_rtc_interrupt(int irq, void *data)
 195{
 196        struct rtc_plat_data *pdata = data;
 197        void __iomem *ioaddr = pdata->ioaddr;
 198
 199        /* alarm irq? */
 200        if (!readl(ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS))
 201                return IRQ_NONE;
 202
 203        /* clear interrupt */
 204        writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
 205        rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF);
 206        return IRQ_HANDLED;
 207}
 208
 209static const struct rtc_class_ops mv_rtc_ops = {
 210        .read_time      = mv_rtc_read_time,
 211        .set_time       = mv_rtc_set_time,
 212};
 213
 214static const struct rtc_class_ops mv_rtc_alarm_ops = {
 215        .read_time      = mv_rtc_read_time,
 216        .set_time       = mv_rtc_set_time,
 217        .read_alarm     = mv_rtc_read_alarm,
 218        .set_alarm      = mv_rtc_set_alarm,
 219        .ioctl          = mv_rtc_ioctl,
 220};
 221
 222static int __devinit mv_rtc_probe(struct platform_device *pdev)
 223{
 224        struct resource *res;
 225        struct rtc_plat_data *pdata;
 226        resource_size_t size;
 227        u32 rtc_time;
 228
 229        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 230        if (!res)
 231                return -ENODEV;
 232
 233        pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 234        if (!pdata)
 235                return -ENOMEM;
 236
 237        size = resource_size(res);
 238        if (!devm_request_mem_region(&pdev->dev, res->start, size,
 239                                     pdev->name))
 240                return -EBUSY;
 241
 242        pdata->ioaddr = devm_ioremap(&pdev->dev, res->start, size);
 243        if (!pdata->ioaddr)
 244                return -ENOMEM;
 245
 246        /* make sure the 24 hours mode is enabled */
 247        rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
 248        if (rtc_time & RTC_HOURS_12H_MODE) {
 249                dev_err(&pdev->dev, "24 Hours mode not supported.\n");
 250                return -EINVAL;
 251        }
 252
 253        /* make sure it is actually functional */
 254        if (rtc_time == 0x01000000) {
 255                ssleep(1);
 256                rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
 257                if (rtc_time == 0x01000000) {
 258                        dev_err(&pdev->dev, "internal RTC not ticking\n");
 259                        return -ENODEV;
 260                }
 261        }
 262
 263        pdata->irq = platform_get_irq(pdev, 0);
 264
 265        platform_set_drvdata(pdev, pdata);
 266
 267        if (pdata->irq >= 0) {
 268                device_init_wakeup(&pdev->dev, 1);
 269                pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
 270                                                 &mv_rtc_alarm_ops,
 271                                                 THIS_MODULE);
 272        } else
 273                pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
 274                                                 &mv_rtc_ops, THIS_MODULE);
 275        if (IS_ERR(pdata->rtc))
 276                return PTR_ERR(pdata->rtc);
 277
 278        if (pdata->irq >= 0) {
 279                writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 280                if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt,
 281                                     IRQF_DISABLED | IRQF_SHARED,
 282                                     pdev->name, pdata) < 0) {
 283                        dev_warn(&pdev->dev, "interrupt not available.\n");
 284                        pdata->irq = -1;
 285                }
 286        }
 287
 288        return 0;
 289}
 290
 291static int __exit mv_rtc_remove(struct platform_device *pdev)
 292{
 293        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 294
 295        if (pdata->irq >= 0)
 296                device_init_wakeup(&pdev->dev, 0);
 297
 298        rtc_device_unregister(pdata->rtc);
 299        return 0;
 300}
 301
 302static struct platform_driver mv_rtc_driver = {
 303        .remove         = __exit_p(mv_rtc_remove),
 304        .driver         = {
 305                .name   = "rtc-mv",
 306                .owner  = THIS_MODULE,
 307        },
 308};
 309
 310static __init int mv_init(void)
 311{
 312        return platform_driver_probe(&mv_rtc_driver, mv_rtc_probe);
 313}
 314
 315static __exit void mv_exit(void)
 316{
 317        platform_driver_unregister(&mv_rtc_driver);
 318}
 319
 320module_init(mv_init);
 321module_exit(mv_exit);
 322
 323MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
 324MODULE_DESCRIPTION("Marvell RTC driver");
 325MODULE_LICENSE("GPL");
 326MODULE_ALIAS("platform:rtc-mv");
 327
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.