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