drivers/rtc/rtc-rp5c01.c

   1 /*
   2  *  Ricoh RP5C01 RTC Driver
   3  *
   4  *  Copyright 2009 Geert Uytterhoeven
   5  *
   6  *  Based on the A3000 TOD code in arch/m68k/amiga/config.c
   7  *  Copyright (C) 1993 Hamish Macdonald
   8  */
   9
  10 #include <linux/io.h>
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/rtc.h>
  15
  16
  17 enum {
  18         RP5C01_1_SECOND         = 0x0,  /* MODE 00 */
  19         RP5C01_10_SECOND        = 0x1,  /* MODE 00 */
  20         RP5C01_1_MINUTE         = 0x2,  /* MODE 00 and MODE 01 */
  21         RP5C01_10_MINUTE        = 0x3,  /* MODE 00 and MODE 01 */
  22         RP5C01_1_HOUR           = 0x4,  /* MODE 00 and MODE 01 */
  23         RP5C01_10_HOUR          = 0x5,  /* MODE 00 and MODE 01 */
  24         RP5C01_DAY_OF_WEEK      = 0x6,  /* MODE 00 and MODE 01 */
  25         RP5C01_1_DAY            = 0x7,  /* MODE 00 and MODE 01 */
  26         RP5C01_10_DAY           = 0x8,  /* MODE 00 and MODE 01 */
  27         RP5C01_1_MONTH          = 0x9,  /* MODE 00 */
  28         RP5C01_10_MONTH         = 0xa,  /* MODE 00 */
  29         RP5C01_1_YEAR           = 0xb,  /* MODE 00 */
  30         RP5C01_10_YEAR          = 0xc,  /* MODE 00 */
  31
  32         RP5C01_12_24_SELECT     = 0xa,  /* MODE 01 */
  33         RP5C01_LEAP_YEAR        = 0xb,  /* MODE 01 */
  34
  35         RP5C01_MODE             = 0xd,  /* all modes */
  36         RP5C01_TEST             = 0xe,  /* all modes */
  37         RP5C01_RESET            = 0xf,  /* all modes */
  38 };
  39
  40 #define RP5C01_12_24_SELECT_12  (0 << 0)
  41 #define RP5C01_12_24_SELECT_24  (1 << 0)
  42
  43 #define RP5C01_10_HOUR_AM       (0 << 1)
  44 #define RP5C01_10_HOUR_PM       (1 << 1)
  45
  46 #define RP5C01_MODE_TIMER_EN    (1 << 3)        /* timer enable */
  47 #define RP5C01_MODE_ALARM_EN    (1 << 2)        /* alarm enable */
  48
  49 #define RP5C01_MODE_MODE_MASK   (3 << 0)
  50 #define RP5C01_MODE_MODE00      (0 << 0)        /* time */
  51 #define RP5C01_MODE_MODE01      (1 << 0)        /* alarm, 12h/24h, leap year */
  52 #define RP5C01_MODE_RAM_BLOCK10 (2 << 0)        /* RAM 4 bits x 13 */
  53 #define RP5C01_MODE_RAM_BLOCK11 (3 << 0)        /* RAM 4 bits x 13 */
  54
  55 #define RP5C01_RESET_1HZ_PULSE  (1 << 3)
  56 #define RP5C01_RESET_16HZ_PULSE (1 << 2)
  57 #define RP5C01_RESET_SECOND     (1 << 1)        /* reset divider stages for */
  58                                                 /* seconds or smaller units */
  59 #define RP5C01_RESET_ALARM      (1 << 0)        /* reset all alarm registers */
  60
  61
  62 struct rp5c01_priv {
  63         u32 __iomem *regs;
  64         struct rtc_device *rtc;
  65 };
  66
  67 static inline unsigned int rp5c01_read(struct rp5c01_priv *priv,
  68                                        unsigned int reg)
  69 {
  70         return __raw_readl(&priv->regs[reg]) & 0xf;
  71 }
  72
  73 static inline void rp5c01_write(struct rp5c01_priv *priv, unsigned int val,
  74                                 unsigned int reg)
  75 {
  76         return __raw_writel(val, &priv->regs[reg]);
  77 }
  78
  79 static void rp5c01_lock(struct rp5c01_priv *priv)
  80 {
  81         rp5c01_write(priv, RP5C01_MODE_MODE00, RP5C01_MODE);
  82 }
  83
  84 static void rp5c01_unlock(struct rp5c01_priv *priv)
  85 {
  86         rp5c01_write(priv, RP5C01_MODE_TIMER_EN | RP5C01_MODE_MODE01,
  87                      RP5C01_MODE);
  88 }
  89
  90 static int rp5c01_read_time(struct device *dev, struct rtc_time *tm)
  91 {
  92         struct rp5c01_priv *priv = dev_get_drvdata(dev);
  93
  94         rp5c01_lock(priv);
  95
  96         tm->tm_sec  = rp5c01_read(priv, RP5C01_10_SECOND) * 10 +
  97                       rp5c01_read(priv, RP5C01_1_SECOND);
  98         tm->tm_min  = rp5c01_read(priv, RP5C01_10_MINUTE) * 10 +
  99                       rp5c01_read(priv, RP5C01_1_MINUTE);
 100         tm->tm_hour = rp5c01_read(priv, RP5C01_10_HOUR) * 10 +
 101                       rp5c01_read(priv, RP5C01_1_HOUR);
 102         tm->tm_mday = rp5c01_read(priv, RP5C01_10_DAY) * 10 +
 103                       rp5c01_read(priv, RP5C01_1_DAY);
 104         tm->tm_wday = rp5c01_read(priv, RP5C01_DAY_OF_WEEK);
 105         tm->tm_mon  = rp5c01_read(priv, RP5C01_10_MONTH) * 10 +
 106                       rp5c01_read(priv, RP5C01_1_MONTH) - 1;
 107         tm->tm_year = rp5c01_read(priv, RP5C01_10_YEAR) * 10 +
 108                       rp5c01_read(priv, RP5C01_1_YEAR);
 109         if (tm->tm_year <= 69)
 110                 tm->tm_year += 100;
 111
 112         rp5c01_unlock(priv);
 113
 114         return rtc_valid_tm(tm);
 115 }
 116
 117 static int rp5c01_set_time(struct device *dev, struct rtc_time *tm)
 118 {
 119         struct rp5c01_priv *priv = dev_get_drvdata(dev);
 120
 121         rp5c01_lock(priv);
 122
 123         rp5c01_write(priv, tm->tm_sec / 10, RP5C01_10_SECOND);
 124         rp5c01_write(priv, tm->tm_sec % 10, RP5C01_1_SECOND);
 125         rp5c01_write(priv, tm->tm_min / 10, RP5C01_10_MINUTE);
 126         rp5c01_write(priv, tm->tm_min % 10, RP5C01_1_MINUTE);
 127         rp5c01_write(priv, tm->tm_hour / 10, RP5C01_10_HOUR);
 128         rp5c01_write(priv, tm->tm_hour % 10, RP5C01_1_HOUR);
 129         rp5c01_write(priv, tm->tm_mday / 10, RP5C01_10_DAY);
 130         rp5c01_write(priv, tm->tm_mday % 10, RP5C01_1_DAY);
 131         if (tm->tm_wday != -1)
 132                 rp5c01_write(priv, tm->tm_wday, RP5C01_DAY_OF_WEEK);
 133         rp5c01_write(priv, (tm->tm_mon + 1) / 10, RP5C01_10_MONTH);
 134         rp5c01_write(priv, (tm->tm_mon + 1) % 10, RP5C01_1_MONTH);
 135         if (tm->tm_year >= 100)
 136                 tm->tm_year -= 100;
 137         rp5c01_write(priv, tm->tm_year / 10, RP5C01_10_YEAR);
 138         rp5c01_write(priv, tm->tm_year % 10, RP5C01_1_YEAR);
 139
 140         rp5c01_unlock(priv);
 141         return 0;
 142 }
 143
 144 static const struct rtc_class_ops rp5c01_rtc_ops = {
 145         .read_time      = rp5c01_read_time,
 146         .set_time       = rp5c01_set_time,
 147 };
 148
 149 static int __init rp5c01_rtc_probe(struct platform_device *dev)
 150 {
 151         struct resource *res;
 152         struct rp5c01_priv *priv;
 153         struct rtc_device *rtc;
 154         int error;
 155
 156         res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 157         if (!res)
 158                 return -ENODEV;
 159
 160         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 161         if (!priv)
 162                 return -ENOMEM;
 163
 164         priv->regs = ioremap(res->start, resource_size(res));
 165         if (!priv->regs) {
 166                 error = -ENOMEM;
 167                 goto out_free_priv;
 168         }
 169
 170         rtc = rtc_device_register("rtc-rp5c01", &dev->dev, &rp5c01_rtc_ops,
 171                                   THIS_MODULE);
 172         if (IS_ERR(rtc)) {
 173                 error = PTR_ERR(rtc);
 174                 goto out_unmap;
 175         }
 176
 177         priv->rtc = rtc;
 178         platform_set_drvdata(dev, priv);
 179         return 0;
 180
 181 out_unmap:
 182         iounmap(priv->regs);
 183 out_free_priv:
 184         kfree(priv);
 185         return error;
 186 }
 187
 188 static int __exit rp5c01_rtc_remove(struct platform_device *dev)
 189 {
 190         struct rp5c01_priv *priv = platform_get_drvdata(dev);
 191
 192         rtc_device_unregister(priv->rtc);
 193         iounmap(priv->regs);
 194         kfree(priv);
 195         return 0;
 196 }
 197
 198 static struct platform_driver rp5c01_rtc_driver = {
 199         .driver = {
 200                 .name   = "rtc-rp5c01",
 201                 .owner  = THIS_MODULE,
 202         },
 203         .remove = __exit_p(rp5c01_rtc_remove),
 204 };
 205
 206 static int __init rp5c01_rtc_init(void)
 207 {
 208         return platform_driver_probe(&rp5c01_rtc_driver, rp5c01_rtc_probe);
 209 }
 210
 211 static void __exit rp5c01_rtc_fini(void)
 212 {
 213         platform_driver_unregister(&rp5c01_rtc_driver);
 214 }
 215
 216 module_init(rp5c01_rtc_init);
 217 module_exit(rp5c01_rtc_fini);
 218
 219 MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
 220 MODULE_LICENSE("GPL");
 221 MODULE_DESCRIPTION("Ricoh RP5C01 RTC driver");
 222 MODULE_ALIAS("platform:rtc-rp5c01");