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 #include <linux/module.h>
  18
  19
  20 #define RTC_TIME_REG_OFFS       0
  21 #define RTC_SECONDS_OFFS        0
  22 #define RTC_MINUTES_OFFS        8
  23 #define RTC_HOURS_OFFS          16
  24 #define RTC_WDAY_OFFS           24
  25 #define RTC_HOURS_12H_MODE              (1 << 22) /* 12 hours mode */
  26
  27 #define RTC_DATE_REG_OFFS       4
  28 #define RTC_MDAY_OFFS           0
  29 #define RTC_MONTH_OFFS          8
  30 #define RTC_YEAR_OFFS           16
  31
  32 #define RTC_ALARM_TIME_REG_OFFS 8
  33 #define RTC_ALARM_DATE_REG_OFFS 0xc
  34 #define RTC_ALARM_VALID         (1 << 7)
  35
  36 #define RTC_ALARM_INTERRUPT_MASK_REG_OFFS       0x10
  37 #define RTC_ALARM_INTERRUPT_CASUE_REG_OFFS      0x14
  38
  39 struct rtc_plat_data {
  40         struct rtc_device *rtc;
  41         void __iomem *ioaddr;
  42         int             irq;
  43 };
  44
  45 static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm)
  46 {
  47         struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  48         void __iomem *ioaddr = pdata->ioaddr;
  49         u32     rtc_reg;
  50
  51         rtc_reg = (bin2bcd(tm->tm_sec) << RTC_SECONDS_OFFS) |
  52                 (bin2bcd(tm->tm_min) << RTC_MINUTES_OFFS) |
  53                 (bin2bcd(tm->tm_hour) << RTC_HOURS_OFFS) |
  54                 (bin2bcd(tm->tm_wday) << RTC_WDAY_OFFS);
  55         writel(rtc_reg, ioaddr + RTC_TIME_REG_OFFS);
  56
  57         rtc_reg = (bin2bcd(tm->tm_mday) << RTC_MDAY_OFFS) |
  58                 (bin2bcd(tm->tm_mon + 1) << RTC_MONTH_OFFS) |
  59                 (bin2bcd(tm->tm_year % 100) << RTC_YEAR_OFFS);
  60         writel(rtc_reg, ioaddr + RTC_DATE_REG_OFFS);
  61
  62         return 0;
  63 }
  64
  65 static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm)
  66 {
  67         struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  68         void __iomem *ioaddr = pdata->ioaddr;
  69         u32     rtc_time, rtc_date;
  70         unsigned int year, month, day, hour, minute, second, wday;
  71
  72         rtc_time = readl(ioaddr + RTC_TIME_REG_OFFS);
  73         rtc_date = readl(ioaddr + RTC_DATE_REG_OFFS);
  74
  75         second = rtc_time & 0x7f;
  76         minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
  77         hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hours mode */
  78         wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
  79
  80         day = rtc_date & 0x3f;
  81         month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
  82         year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
  83
  84         tm->tm_sec = bcd2bin(second);
  85         tm->tm_min = bcd2bin(minute);
  86         tm->tm_hour = bcd2bin(hour);
  87         tm->tm_mday = bcd2bin(day);
  88         tm->tm_wday = bcd2bin(wday);
  89         tm->tm_mon = bcd2bin(month) - 1;
  90         /* hw counts from year 2000, but tm_year is relative to 1900 */
  91         tm->tm_year = bcd2bin(year) + 100;
  92
  93         return rtc_valid_tm(tm);
  94 }
  95
  96 static int mv_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
  97 {
  98         struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  99         void __iomem *ioaddr = pdata->ioaddr;
 100         u32     rtc_time, rtc_date;
 101         unsigned int year, month, day, hour, minute, second, wday;
 102
 103         rtc_time = readl(ioaddr + RTC_ALARM_TIME_REG_OFFS);
 104         rtc_date = readl(ioaddr + RTC_ALARM_DATE_REG_OFFS);
 105
 106         second = rtc_time & 0x7f;
 107         minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
 108         hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hours mode */
 109         wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
 110
 111         day = rtc_date & 0x3f;
 112         month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
 113         year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
 114
 115         alm->time.tm_sec = bcd2bin(second);
 116         alm->time.tm_min = bcd2bin(minute);
 117         alm->time.tm_hour = bcd2bin(hour);
 118         alm->time.tm_mday = bcd2bin(day);
 119         alm->time.tm_wday = bcd2bin(wday);
 120         alm->time.tm_mon = bcd2bin(month) - 1;
 121         /* hw counts from year 2000, but tm_year is relative to 1900 */
 122         alm->time.tm_year = bcd2bin(year) + 100;
 123
 124         if (rtc_valid_tm(&alm->time) < 0) {
 125                 dev_err(dev, "retrieved alarm date/time is not valid.\n");
 126                 rtc_time_to_tm(0, &alm->time);
 127         }
 128
 129         alm->enabled = !!readl(ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 130         return 0;
 131 }
 132
 133 static int mv_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 134 {
 135         struct rtc_plat_data *pdata = dev_get_drvdata(dev);
 136         void __iomem *ioaddr = pdata->ioaddr;
 137         u32 rtc_reg = 0;
 138
 139         if (alm->time.tm_sec >= 0)
 140                 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_sec))
 141                         << RTC_SECONDS_OFFS;
 142         if (alm->time.tm_min >= 0)
 143                 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_min))
 144                         << RTC_MINUTES_OFFS;
 145         if (alm->time.tm_hour >= 0)
 146                 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_hour))
 147                         << RTC_HOURS_OFFS;
 148
 149         writel(rtc_reg, ioaddr + RTC_ALARM_TIME_REG_OFFS);
 150
 151         if (alm->time.tm_mday >= 0)
 152                 rtc_reg = (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mday))
 153                         << RTC_MDAY_OFFS;
 154         else
 155                 rtc_reg = 0;
 156
 157         if (alm->time.tm_mon >= 0)
 158                 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mon + 1))
 159                         << RTC_MONTH_OFFS;
 160
 161         if (alm->time.tm_year >= 0)
 162                 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_year % 100))
 163                         << RTC_YEAR_OFFS;
 164
 165         writel(rtc_reg, ioaddr + RTC_ALARM_DATE_REG_OFFS);
 166         writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
 167         writel(alm->enabled ? 1 : 0,
 168                ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 169
 170         return 0;
 171 }
 172
 173 static int mv_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 174 {
 175         struct platform_device *pdev = to_platform_device(dev);
 176         struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 177         void __iomem *ioaddr = pdata->ioaddr;
 178
 179         if (pdata->irq < 0)
 180                 return -EINVAL; /* fall back into rtc-dev's emulation */
 181
 182         if (enabled)
 183                 writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 184         else
 185                 writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 186         return 0;
 187 }
 188
 189 static irqreturn_t mv_rtc_interrupt(int irq, void *data)
 190 {
 191         struct rtc_plat_data *pdata = data;
 192         void __iomem *ioaddr = pdata->ioaddr;
 193
 194         /* alarm irq? */
 195         if (!readl(ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS))
 196                 return IRQ_NONE;
 197
 198         /* clear interrupt */
 199         writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
 200         rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF);
 201         return IRQ_HANDLED;
 202 }
 203
 204 static const struct rtc_class_ops mv_rtc_ops = {
 205         .read_time      = mv_rtc_read_time,
 206         .set_time       = mv_rtc_set_time,
 207 };
 208
 209 static const struct rtc_class_ops mv_rtc_alarm_ops = {
 210         .read_time      = mv_rtc_read_time,
 211         .set_time       = mv_rtc_set_time,
 212         .read_alarm     = mv_rtc_read_alarm,
 213         .set_alarm      = mv_rtc_set_alarm,
 214         .alarm_irq_enable = mv_rtc_alarm_irq_enable,
 215 };
 216
 217 static int __devinit mv_rtc_probe(struct platform_device *pdev)
 218 {
 219         struct resource *res;
 220         struct rtc_plat_data *pdata;
 221         resource_size_t size;
 222         u32 rtc_time;
 223
 224         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 225         if (!res)
 226                 return -ENODEV;
 227
 228         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 229         if (!pdata)
 230                 return -ENOMEM;
 231
 232         size = resource_size(res);
 233         if (!devm_request_mem_region(&pdev->dev, res->start, size,
 234                                      pdev->name))
 235                 return -EBUSY;
 236
 237         pdata->ioaddr = devm_ioremap(&pdev->dev, res->start, size);
 238         if (!pdata->ioaddr)
 239                 return -ENOMEM;
 240
 241         /* make sure the 24 hours mode is enabled */
 242         rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
 243         if (rtc_time & RTC_HOURS_12H_MODE) {
 244                 dev_err(&pdev->dev, "24 Hours mode not supported.\n");
 245                 return -EINVAL;
 246         }
 247
 248         /* make sure it is actually functional */
 249         if (rtc_time == 0x01000000) {
 250                 ssleep(1);
 251                 rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
 252                 if (rtc_time == 0x01000000) {
 253                         dev_err(&pdev->dev, "internal RTC not ticking\n");
 254                         return -ENODEV;
 255                 }
 256         }
 257
 258         pdata->irq = platform_get_irq(pdev, 0);
 259
 260         platform_set_drvdata(pdev, pdata);
 261
 262         if (pdata->irq >= 0) {
 263                 device_init_wakeup(&pdev->dev, 1);
 264                 pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
 265                                                  &mv_rtc_alarm_ops,
 266                                                  THIS_MODULE);
 267         } else
 268                 pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
 269                                                  &mv_rtc_ops, THIS_MODULE);
 270         if (IS_ERR(pdata->rtc))
 271                 return PTR_ERR(pdata->rtc);
 272
 273         if (pdata->irq >= 0) {
 274                 writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
 275                 if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt,
 276                                      IRQF_DISABLED | IRQF_SHARED,
 277                                      pdev->name, pdata) < 0) {
 278                         dev_warn(&pdev->dev, "interrupt not available.\n");
 279                         pdata->irq = -1;
 280                 }
 281         }
 282
 283         return 0;
 284 }
 285
 286 static int __exit mv_rtc_remove(struct platform_device *pdev)
 287 {
 288         struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 289
 290         if (pdata->irq >= 0)
 291                 device_init_wakeup(&pdev->dev, 0);
 292
 293         rtc_device_unregister(pdata->rtc);
 294         return 0;
 295 }
 296
 297 static struct platform_driver mv_rtc_driver = {
 298         .remove         = __exit_p(mv_rtc_remove),
 299         .driver         = {
 300                 .name   = "rtc-mv",
 301                 .owner  = THIS_MODULE,
 302         },
 303 };
 304
 305 static __init int mv_init(void)
 306 {
 307         return platform_driver_probe(&mv_rtc_driver, mv_rtc_probe);
 308 }
 309
 310 static __exit void mv_exit(void)
 311 {
 312         platform_driver_unregister(&mv_rtc_driver);
 313 }
 314
 315 module_init(mv_init);
 316 module_exit(mv_exit);
 317
 318 MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
 319 MODULE_DESCRIPTION("Marvell RTC driver");
 320 MODULE_LICENSE("GPL");
 321 MODULE_ALIAS("platform:rtc-mv");