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/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
  41 struct rtc_plat_data {
  42         struct rtc_device *rtc;
  43         void __iomem *ioaddr;
  44         int             irq;
  45         struct clk      *clk;
  46 };
  47
  48 static 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
  68 static 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
  99 static 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
 136 static 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
 176 static 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
 192 static 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
 207 static const struct rtc_class_ops mv_rtc_ops = {
 208         .read_time      = mv_rtc_read_time,
 209         .set_time       = mv_rtc_set_time,
 210 };
 211
 212 static 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
 220 static int __init mv_rtc_probe(struct platform_device *pdev)
 221 {
 222         struct resource *res;
 223         struct rtc_plat_data *pdata;
 224         u32 rtc_time;
 225         u32 rtc_date;
 226         int ret = 0;
 227
 228         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 229         if (!pdata)
 230                 return -ENOMEM;
 231
 232         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 233         pdata->ioaddr = devm_ioremap_resource(&pdev->dev, res);
 234         if (IS_ERR(pdata->ioaddr))
 235                 return PTR_ERR(pdata->ioaddr);
 236
 237         pdata->clk = devm_clk_get(&pdev->dev, NULL);
 238         /* Not all SoCs require a clock.*/
 239         if (!IS_ERR(pdata->clk))
 240                 clk_prepare_enable(pdata->clk);
 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                 ret = -EINVAL;
 247                 goto out;
 248         }
 249
 250         /* make sure it is actually functional */
 251         if (rtc_time == 0x01000000) {
 252                 ssleep(1);
 253                 rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
 254                 if (rtc_time == 0x01000000) {
 255                         dev_err(&pdev->dev, "internal RTC not ticking\n");
 256                         ret = -ENODEV;
 257                         goto out;
 258                 }
 259         }
 260
 261         /*
 262          * A date after January 19th, 2038 does not fit on 32 bits and
 263          * will confuse the kernel and userspace. Reset to a sane date
 264          * (January 1st, 2013) if we're after 2038.
 265          */
 266         rtc_date = readl(pdata->ioaddr + RTC_DATE_REG_OFFS);
 267         if (bcd2bin((rtc_date >> RTC_YEAR_OFFS) & 0xff) >= 38) {
 268                 dev_info(&pdev->dev, "invalid RTC date, resetting to January 1st, 2013\n");
 269                 writel(0x130101, pdata->ioaddr + RTC_DATE_REG_OFFS);
 270         }
 271
 272         pdata->irq = platform_get_irq(pdev, 0);
 273
 274         platform_set_drvdata(pdev, pdata);
 275
 276         if (pdata->irq >= 0) {
 277                 device_init_wakeup(&pdev->dev, 1);
 278                 pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
 279                                                  &mv_rtc_alarm_ops,
 280                                                  THIS_MODULE);
 281         } else {
 282                 pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
 283                                                  &mv_rtc_ops, THIS_MODULE);
 284         }
 285         if (IS_ERR(pdata->rtc)) {
 286                 ret = PTR_ERR(pdata->rtc);
 287                 goto out;
 288         }
 289
 290         if (pdata->irq >= 0) {
 291                 writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 292                 if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt,
 293                                      IRQF_SHARED,
 294                                      pdev->name, pdata) < 0) {
 295                         dev_warn(&pdev->dev, "interrupt not available.\n");
 296                         pdata->irq = -1;
 297                 }
 298         }
 299
 300         return 0;
 301 out:
 302         if (!IS_ERR(pdata->clk))
 303                 clk_disable_unprepare(pdata->clk);
 304
 305         return ret;
 306 }
 307
 308 static int __exit mv_rtc_remove(struct platform_device *pdev)
 309 {
 310         struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 311
 312         if (pdata->irq >= 0)
 313                 device_init_wakeup(&pdev->dev, 0);
 314
 315         if (!IS_ERR(pdata->clk))
 316                 clk_disable_unprepare(pdata->clk);
 317
 318         return 0;
 319 }
 320
 321 #ifdef CONFIG_OF
 322 static const struct of_device_id rtc_mv_of_match_table[] = {
 323         { .compatible = "marvell,orion-rtc", },
 324         {}
 325 };
 326 #endif
 327
 328 static struct platform_driver mv_rtc_driver = {
 329         .remove         = __exit_p(mv_rtc_remove),
 330         .driver         = {
 331                 .name   = "rtc-mv",
 332                 .of_match_table = of_match_ptr(rtc_mv_of_match_table),
 333         },
 334 };
 335
 336 module_platform_driver_probe(mv_rtc_driver, mv_rtc_probe);
 337
 338 MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
 339 MODULE_DESCRIPTION("Marvell RTC driver");
 340 MODULE_LICENSE("GPL");
 341 MODULE_ALIAS("platform:rtc-mv");