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/bitops.h>
  14 #include <linux/io.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/of.h>
  17 #include <linux/delay.h>
  18 #include <linux/clk.h>
  19 #include <linux/gfp.h>
  20 #include <linux/module.h>
  21
  22
  23 #define RTC_TIME_REG_OFFS       0
  24 #define RTC_SECONDS_OFFS        0
  25 #define RTC_MINUTES_OFFS        8
  26 #define RTC_HOURS_OFFS          16
  27 #define RTC_WDAY_OFFS           24
  28 #define RTC_HOURS_12H_MODE      BIT(22) /* 12 hour mode */
  29
  30 #define RTC_DATE_REG_OFFS       4
  31 #define RTC_MDAY_OFFS           0
  32 #define RTC_MONTH_OFFS          8
  33 #define RTC_YEAR_OFFS           16
  34
  35 #define RTC_ALARM_TIME_REG_OFFS 8
  36 #define RTC_ALARM_DATE_REG_OFFS 0xc
  37 #define RTC_ALARM_VALID         BIT(7)
  38
  39 #define RTC_ALARM_INTERRUPT_MASK_REG_OFFS       0x10
  40 #define RTC_ALARM_INTERRUPT_CASUE_REG_OFFS      0x14
  41
  42 struct rtc_plat_data {
  43         struct rtc_device *rtc;
  44         void __iomem *ioaddr;
  45         int             irq;
  46         struct clk      *clk;
  47 };
  48
  49 static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm)
  50 {
  51         struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  52         void __iomem *ioaddr = pdata->ioaddr;
  53         u32     rtc_reg;
  54
  55         rtc_reg = (bin2bcd(tm->tm_sec) << RTC_SECONDS_OFFS) |
  56                 (bin2bcd(tm->tm_min) << RTC_MINUTES_OFFS) |
  57                 (bin2bcd(tm->tm_hour) << RTC_HOURS_OFFS) |
  58                 (bin2bcd(tm->tm_wday) << RTC_WDAY_OFFS);
  59         writel(rtc_reg, ioaddr + RTC_TIME_REG_OFFS);
  60
  61         rtc_reg = (bin2bcd(tm->tm_mday) << RTC_MDAY_OFFS) |
  62                 (bin2bcd(tm->tm_mon + 1) << RTC_MONTH_OFFS) |
  63                 (bin2bcd(tm->tm_year % 100) << RTC_YEAR_OFFS);
  64         writel(rtc_reg, ioaddr + RTC_DATE_REG_OFFS);
  65
  66         return 0;
  67 }
  68
  69 static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm)
  70 {
  71         struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  72         void __iomem *ioaddr = pdata->ioaddr;
  73         u32     rtc_time, rtc_date;
  74         unsigned int year, month, day, hour, minute, second, wday;
  75
  76         rtc_time = readl(ioaddr + RTC_TIME_REG_OFFS);
  77         rtc_date = readl(ioaddr + RTC_DATE_REG_OFFS);
  78
  79         second = rtc_time & 0x7f;
  80         minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
  81         hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hour mode */
  82         wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
  83
  84         day = rtc_date & 0x3f;
  85         month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
  86         year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
  87
  88         tm->tm_sec = bcd2bin(second);
  89         tm->tm_min = bcd2bin(minute);
  90         tm->tm_hour = bcd2bin(hour);
  91         tm->tm_mday = bcd2bin(day);
  92         tm->tm_wday = bcd2bin(wday);
  93         tm->tm_mon = bcd2bin(month) - 1;
  94         /* hw counts from year 2000, but tm_year is relative to 1900 */
  95         tm->tm_year = bcd2bin(year) + 100;
  96
  97         return rtc_valid_tm(tm);
  98 }
  99
 100 static int mv_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 101 {
 102         struct rtc_plat_data *pdata = dev_get_drvdata(dev);
 103         void __iomem *ioaddr = pdata->ioaddr;
 104         u32     rtc_time, rtc_date;
 105         unsigned int year, month, day, hour, minute, second, wday;
 106
 107         rtc_time = readl(ioaddr + RTC_ALARM_TIME_REG_OFFS);
 108         rtc_date = readl(ioaddr + RTC_ALARM_DATE_REG_OFFS);
 109
 110         second = rtc_time & 0x7f;
 111         minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
 112         hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hour mode */
 113         wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
 114
 115         day = rtc_date & 0x3f;
 116         month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
 117         year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
 118
 119         alm->time.tm_sec = bcd2bin(second);
 120         alm->time.tm_min = bcd2bin(minute);
 121         alm->time.tm_hour = bcd2bin(hour);
 122         alm->time.tm_mday = bcd2bin(day);
 123         alm->time.tm_wday = bcd2bin(wday);
 124         alm->time.tm_mon = bcd2bin(month) - 1;
 125         /* hw counts from year 2000, but tm_year is relative to 1900 */
 126         alm->time.tm_year = bcd2bin(year) + 100;
 127
 128         if (rtc_valid_tm(&alm->time) < 0) {
 129                 dev_err(dev, "retrieved alarm date/time is not valid.\n");
 130                 rtc_time_to_tm(0, &alm->time);
 131         }
 132
 133         alm->enabled = !!readl(ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 134         return 0;
 135 }
 136
 137 static int mv_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 138 {
 139         struct rtc_plat_data *pdata = dev_get_drvdata(dev);
 140         void __iomem *ioaddr = pdata->ioaddr;
 141         u32 rtc_reg = 0;
 142
 143         if (alm->time.tm_sec >= 0)
 144                 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_sec))
 145                         << RTC_SECONDS_OFFS;
 146         if (alm->time.tm_min >= 0)
 147                 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_min))
 148                         << RTC_MINUTES_OFFS;
 149         if (alm->time.tm_hour >= 0)
 150                 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_hour))
 151                         << RTC_HOURS_OFFS;
 152
 153         writel(rtc_reg, ioaddr + RTC_ALARM_TIME_REG_OFFS);
 154
 155         if (alm->time.tm_mday >= 0)
 156                 rtc_reg = (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mday))
 157                         << RTC_MDAY_OFFS;
 158         else
 159                 rtc_reg = 0;
 160
 161         if (alm->time.tm_mon >= 0)
 162                 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mon + 1))
 163                         << RTC_MONTH_OFFS;
 164
 165         if (alm->time.tm_year >= 0)
 166                 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_year % 100))
 167                         << RTC_YEAR_OFFS;
 168
 169         writel(rtc_reg, ioaddr + RTC_ALARM_DATE_REG_OFFS);
 170         writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
 171         writel(alm->enabled ? 1 : 0,
 172                ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 173
 174         return 0;
 175 }
 176
 177 static int mv_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 178 {
 179         struct platform_device *pdev = to_platform_device(dev);
 180         struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 181         void __iomem *ioaddr = pdata->ioaddr;
 182
 183         if (pdata->irq < 0)
 184                 return -EINVAL; /* fall back into rtc-dev's emulation */
 185
 186         if (enabled)
 187                 writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 188         else
 189                 writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 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         .alarm_irq_enable = mv_rtc_alarm_irq_enable,
 219 };
 220
 221 static int __init mv_rtc_probe(struct platform_device *pdev)
 222 {
 223         struct resource *res;
 224         struct rtc_plat_data *pdata;
 225         u32 rtc_time;
 226         u32 rtc_date;
 227         int ret = 0;
 228
 229         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 230         if (!pdata)
 231                 return -ENOMEM;
 232
 233         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 234         pdata->ioaddr = devm_ioremap_resource(&pdev->dev, res);
 235         if (IS_ERR(pdata->ioaddr))
 236                 return PTR_ERR(pdata->ioaddr);
 237
 238         pdata->clk = devm_clk_get(&pdev->dev, NULL);
 239         /* Not all SoCs require a clock.*/
 240         if (!IS_ERR(pdata->clk))
 241                 clk_prepare_enable(pdata->clk);
 242
 243         /* make sure the 24 hour mode is enabled */
 244         rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
 245         if (rtc_time & RTC_HOURS_12H_MODE) {
 246                 dev_err(&pdev->dev, "12 Hour mode is enabled but not supported.\n");
 247                 ret = -EINVAL;
 248                 goto out;
 249         }
 250
 251         /* make sure it is actually functional */
 252         if (rtc_time == 0x01000000) {
 253                 ssleep(1);
 254                 rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
 255                 if (rtc_time == 0x01000000) {
 256                         dev_err(&pdev->dev, "internal RTC not ticking\n");
 257                         ret = -ENODEV;
 258                         goto out;
 259                 }
 260         }
 261
 262         /*
 263          * A date after January 19th, 2038 does not fit on 32 bits and
 264          * will confuse the kernel and userspace. Reset to a sane date
 265          * (January 1st, 2013) if we're after 2038.
 266          */
 267         rtc_date = readl(pdata->ioaddr + RTC_DATE_REG_OFFS);
 268         if (bcd2bin((rtc_date >> RTC_YEAR_OFFS) & 0xff) >= 38) {
 269                 dev_info(&pdev->dev, "invalid RTC date, resetting to January 1st, 2013\n");
 270                 writel(0x130101, pdata->ioaddr + RTC_DATE_REG_OFFS);
 271         }
 272
 273         pdata->irq = platform_get_irq(pdev, 0);
 274
 275         platform_set_drvdata(pdev, pdata);
 276
 277         if (pdata->irq >= 0) {
 278                 device_init_wakeup(&pdev->dev, 1);
 279                 pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
 280                                                  &mv_rtc_alarm_ops,
 281                                                  THIS_MODULE);
 282         } else {
 283                 pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
 284                                                  &mv_rtc_ops, THIS_MODULE);
 285         }
 286         if (IS_ERR(pdata->rtc)) {
 287                 ret = PTR_ERR(pdata->rtc);
 288                 goto out;
 289         }
 290
 291         if (pdata->irq >= 0) {
 292                 writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 293                 if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt,
 294                                      IRQF_SHARED,
 295                                      pdev->name, pdata) < 0) {
 296                         dev_warn(&pdev->dev, "interrupt not available.\n");
 297                         pdata->irq = -1;
 298                 }
 299         }
 300
 301         return 0;
 302 out:
 303         if (!IS_ERR(pdata->clk))
 304                 clk_disable_unprepare(pdata->clk);
 305
 306         return ret;
 307 }
 308
 309 static int __exit mv_rtc_remove(struct platform_device *pdev)
 310 {
 311         struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 312
 313         if (pdata->irq >= 0)
 314                 device_init_wakeup(&pdev->dev, 0);
 315
 316         if (!IS_ERR(pdata->clk))
 317                 clk_disable_unprepare(pdata->clk);
 318
 319         return 0;
 320 }
 321
 322 #ifdef CONFIG_OF
 323 static const struct of_device_id rtc_mv_of_match_table[] = {
 324         { .compatible = "marvell,orion-rtc", },
 325         {}
 326 };
 327 MODULE_DEVICE_TABLE(of, rtc_mv_of_match_table);
 328 #endif
 329
 330 static struct platform_driver mv_rtc_driver = {
 331         .remove         = __exit_p(mv_rtc_remove),
 332         .driver         = {
 333                 .name   = "rtc-mv",
 334                 .of_match_table = of_match_ptr(rtc_mv_of_match_table),
 335         },
 336 };
 337
 338 module_platform_driver_probe(mv_rtc_driver, mv_rtc_probe);
 339
 340 MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
 341 MODULE_DESCRIPTION("Marvell RTC driver");
 342 MODULE_LICENSE("GPL");
 343 MODULE_ALIAS("platform:rtc-mv");