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
  16
  17 #define RTC_TIME_REG_OFFS       0
  18 #define RTC_SECONDS_OFFS        0
  19 #define RTC_MINUTES_OFFS        8
  20 #define RTC_HOURS_OFFS          16
  21 #define RTC_WDAY_OFFS           24
  22 #define RTC_HOURS_12H_MODE              (1 << 22) /* 12 hours mode */
  23
  24 #define RTC_DATE_REG_OFFS       4
  25 #define RTC_MDAY_OFFS           0
  26 #define RTC_MONTH_OFFS          8
  27 #define RTC_YEAR_OFFS           16
  28
  29
  30 struct rtc_plat_data {
  31         struct rtc_device *rtc;
  32         void __iomem *ioaddr;
  33 };
  34
  35 static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm)
  36 {
  37         struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  38         void __iomem *ioaddr = pdata->ioaddr;
  39         u32     rtc_reg;
  40
  41         rtc_reg = (bin2bcd(tm->tm_sec) << RTC_SECONDS_OFFS) |
  42                 (bin2bcd(tm->tm_min) << RTC_MINUTES_OFFS) |
  43                 (bin2bcd(tm->tm_hour) << RTC_HOURS_OFFS) |
  44                 (bin2bcd(tm->tm_wday) << RTC_WDAY_OFFS);
  45         writel(rtc_reg, ioaddr + RTC_TIME_REG_OFFS);
  46
  47         rtc_reg = (bin2bcd(tm->tm_mday) << RTC_MDAY_OFFS) |
  48                 (bin2bcd(tm->tm_mon + 1) << RTC_MONTH_OFFS) |
  49                 (bin2bcd(tm->tm_year % 100) << RTC_YEAR_OFFS);
  50         writel(rtc_reg, ioaddr + RTC_DATE_REG_OFFS);
  51
  52         return 0;
  53 }
  54
  55 static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm)
  56 {
  57         struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  58         void __iomem *ioaddr = pdata->ioaddr;
  59         u32     rtc_time, rtc_date;
  60         unsigned int year, month, day, hour, minute, second, wday;
  61
  62         rtc_time = readl(ioaddr + RTC_TIME_REG_OFFS);
  63         rtc_date = readl(ioaddr + RTC_DATE_REG_OFFS);
  64
  65         second = rtc_time & 0x7f;
  66         minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
  67         hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hours mode */
  68         wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
  69
  70         day = rtc_date & 0x3f;
  71         month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
  72         year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
  73
  74         tm->tm_sec = bcd2bin(second);
  75         tm->tm_min = bcd2bin(minute);
  76         tm->tm_hour = bcd2bin(hour);
  77         tm->tm_mday = bcd2bin(day);
  78         tm->tm_wday = bcd2bin(wday);
  79         tm->tm_mon = bcd2bin(month) - 1;
  80         /* hw counts from year 2000, but tm_year is relative to 1900 */
  81         tm->tm_year = bcd2bin(year) + 100;
  82
  83         return rtc_valid_tm(tm);
  84 }
  85
  86 static const struct rtc_class_ops mv_rtc_ops = {
  87         .read_time      = mv_rtc_read_time,
  88         .set_time       = mv_rtc_set_time,
  89 };
  90
  91 static int __init mv_rtc_probe(struct platform_device *pdev)
  92 {
  93         struct resource *res;
  94         struct rtc_plat_data *pdata;
  95         resource_size_t size;
  96         u32 rtc_time;
  97
  98         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  99         if (!res)
 100                 return -ENODEV;
 101
 102         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 103         if (!pdata)
 104                 return -ENOMEM;
 105
 106         size = resource_size(res);
 107         if (!devm_request_mem_region(&pdev->dev, res->start, size,
 108                                      pdev->name))
 109                 return -EBUSY;
 110
 111         pdata->ioaddr = devm_ioremap(&pdev->dev, res->start, size);
 112         if (!pdata->ioaddr)
 113                 return -ENOMEM;
 114
 115         /* make sure the 24 hours mode is enabled */
 116         rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
 117         if (rtc_time & RTC_HOURS_12H_MODE) {
 118                 dev_err(&pdev->dev, "24 Hours mode not supported.\n");
 119                 return -EINVAL;
 120         }
 121
 122         platform_set_drvdata(pdev, pdata);
 123         pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
 124                                          &mv_rtc_ops, THIS_MODULE);
 125         if (IS_ERR(pdata->rtc))
 126                 return PTR_ERR(pdata->rtc);
 127
 128         return 0;
 129 }
 130
 131 static int __exit mv_rtc_remove(struct platform_device *pdev)
 132 {
 133         struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 134
 135         rtc_device_unregister(pdata->rtc);
 136         return 0;
 137 }
 138
 139 static struct platform_driver mv_rtc_driver = {
 140         .remove         = __exit_p(mv_rtc_remove),
 141         .driver         = {
 142                 .name   = "rtc-mv",
 143                 .owner  = THIS_MODULE,
 144         },
 145 };
 146
 147 static __init int mv_init(void)
 148 {
 149         return platform_driver_probe(&mv_rtc_driver, mv_rtc_probe);
 150 }
 151
 152 static __exit void mv_exit(void)
 153 {
 154         platform_driver_unregister(&mv_rtc_driver);
 155 }
 156
 157 module_init(mv_init);
 158 module_exit(mv_exit);
 159
 160 MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
 161 MODULE_DESCRIPTION("Marvell RTC driver");
 162 MODULE_LICENSE("GPL");
 163 MODULE_ALIAS("platform:rtc-mv");