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