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