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_alarm_irq_enable(struct device *dev, unsigned int enabled)
 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 -EINVAL; /* fall back into rtc-dev's emulation */
 180
 181         if (enabled)
 182                 writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 183         else
 184                 writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 185         return 0;
 186 }
 187
 188 static irqreturn_t mv_rtc_interrupt(int irq, void *data)
 189 {
 190         struct rtc_plat_data *pdata = data;
 191         void __iomem *ioaddr = pdata->ioaddr;
 192
 193         /* alarm irq? */
 194         if (!readl(ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS))
 195                 return IRQ_NONE;
 196
 197         /* clear interrupt */
 198         writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
 199         rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF);
 200         return IRQ_HANDLED;
 201 }
 202
 203 static const struct rtc_class_ops mv_rtc_ops = {
 204         .read_time      = mv_rtc_read_time,
 205         .set_time       = mv_rtc_set_time,
 206 };
 207
 208 static const struct rtc_class_ops mv_rtc_alarm_ops = {
 209         .read_time      = mv_rtc_read_time,
 210         .set_time       = mv_rtc_set_time,
 211         .read_alarm     = mv_rtc_read_alarm,
 212         .set_alarm      = mv_rtc_set_alarm,
 213         .alarm_irq_enable = mv_rtc_alarm_irq_enable,
 214 };
 215
 216 static int __devinit mv_rtc_probe(struct platform_device *pdev)
 217 {
 218         struct resource *res;
 219         struct rtc_plat_data *pdata;
 220         resource_size_t size;
 221         u32 rtc_time;
 222
 223         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 224         if (!res)
 225                 return -ENODEV;
 226
 227         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 228         if (!pdata)
 229                 return -ENOMEM;
 230
 231         size = resource_size(res);
 232         if (!devm_request_mem_region(&pdev->dev, res->start, size,
 233                                      pdev->name))
 234                 return -EBUSY;
 235
 236         pdata->ioaddr = devm_ioremap(&pdev->dev, res->start, size);
 237         if (!pdata->ioaddr)
 238                 return -ENOMEM;
 239
 240         /* make sure the 24 hours mode is enabled */
 241         rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
 242         if (rtc_time & RTC_HOURS_12H_MODE) {
 243                 dev_err(&pdev->dev, "24 Hours mode not supported.\n");
 244                 return -EINVAL;
 245         }
 246
 247         /* make sure it is actually functional */
 248         if (rtc_time == 0x01000000) {
 249                 ssleep(1);
 250                 rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
 251                 if (rtc_time == 0x01000000) {
 252                         dev_err(&pdev->dev, "internal RTC not ticking\n");
 253                         return -ENODEV;
 254                 }
 255         }
 256
 257         pdata->irq = platform_get_irq(pdev, 0);
 258
 259         platform_set_drvdata(pdev, pdata);
 260
 261         if (pdata->irq >= 0) {
 262                 device_init_wakeup(&pdev->dev, 1);
 263                 pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
 264                                                  &mv_rtc_alarm_ops,
 265                                                  THIS_MODULE);
 266         } else
 267                 pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
 268                                                  &mv_rtc_ops, THIS_MODULE);
 269         if (IS_ERR(pdata->rtc))
 270                 return PTR_ERR(pdata->rtc);
 271
 272         if (pdata->irq >= 0) {
 273                 writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 274                 if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt,
 275                                      IRQF_DISABLED | IRQF_SHARED,
 276                                      pdev->name, pdata) < 0) {
 277                         dev_warn(&pdev->dev, "interrupt not available.\n");
 278                         pdata->irq = -1;
 279                 }
 280         }
 281
 282         return 0;
 283 }
 284
 285 static int __exit mv_rtc_remove(struct platform_device *pdev)
 286 {
 287         struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 288
 289         if (pdata->irq >= 0)
 290                 device_init_wakeup(&pdev->dev, 0);
 291
 292         rtc_device_unregister(pdata->rtc);
 293         return 0;
 294 }
 295
 296 static struct platform_driver mv_rtc_driver = {
 297         .remove         = __exit_p(mv_rtc_remove),
 298         .driver         = {
 299                 .name   = "rtc-mv",
 300                 .owner  = THIS_MODULE,
 301         },
 302 };
 303
 304 static __init int mv_init(void)
 305 {
 306         return platform_driver_probe(&mv_rtc_driver, mv_rtc_probe);
 307 }
 308
 309 static __exit void mv_exit(void)
 310 {
 311         platform_driver_unregister(&mv_rtc_driver);
 312 }
 313
 314 module_init(mv_init);
 315 module_exit(mv_exit);
 316
 317 MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
 318 MODULE_DESCRIPTION("Marvell RTC driver");
 319 MODULE_LICENSE("GPL");
 320 MODULE_ALIAS("platform:rtc-mv");