drivers/rtc/rtc-mv.c

   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
  38 struct rtc_plat_data {
  39         struct rtc_device *rtc;
  40         void __iomem *ioaddr;
  41         int             irq;
  42 };
  43
  44 static 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
  64 static 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
  95 static 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
 132 static 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
 172 static 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
 194 static 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
 209 static const struct rtc_class_ops mv_rtc_ops = {
 210         .read_time      = mv_rtc_read_time,
 211         .set_time       = mv_rtc_set_time,
 212 };
 213
 214 static 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
 222 static 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
 291 static 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
 302 static 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
 310 static __init int mv_init(void)
 311 {
 312         return platform_driver_probe(&mv_rtc_driver, mv_rtc_probe);
 313 }
 314
 315 static __exit void mv_exit(void)
 316 {
 317         platform_driver_unregister(&mv_rtc_driver);
 318 }
 319
 320 module_init(mv_init);
 321 module_exit(mv_exit);
 322
 323 MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
 324 MODULE_DESCRIPTION("Marvell RTC driver");
 325 MODULE_LICENSE("GPL");
 326 MODULE_ALIAS("platform:rtc-mv");