drivers/rtc/rtc-msm6242.c

   1 /*
   2  *  Oki MSM6242 RTC Driver
   3  *
   4  *  Copyright 2009 Geert Uytterhoeven
   5  *
   6  *  Based on the A2000 TOD code in arch/m68k/amiga/config.c
   7  *  Copyright (C) 1993 Hamish Macdonald
   8  */
   9
  10 #include <linux/delay.h>
  11 #include <linux/io.h>
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/rtc.h>
  16
  17
  18 enum {
  19         MSM6242_SECOND1         = 0x0,  /* 1-second digit register */
  20         MSM6242_SECOND10        = 0x1,  /* 10-second digit register */
  21         MSM6242_MINUTE1         = 0x2,  /* 1-minute digit register */
  22         MSM6242_MINUTE10        = 0x3,  /* 10-minute digit register */
  23         MSM6242_HOUR1           = 0x4,  /* 1-hour digit register */
  24         MSM6242_HOUR10          = 0x5,  /* PM/AM, 10-hour digit register */
  25         MSM6242_DAY1            = 0x6,  /* 1-day digit register */
  26         MSM6242_DAY10           = 0x7,  /* 10-day digit register */
  27         MSM6242_MONTH1          = 0x8,  /* 1-month digit register */
  28         MSM6242_MONTH10         = 0x9,  /* 10-month digit register */
  29         MSM6242_YEAR1           = 0xa,  /* 1-year digit register */
  30         MSM6242_YEAR10          = 0xb,  /* 10-year digit register */
  31         MSM6242_WEEK            = 0xc,  /* Week register */
  32         MSM6242_CD              = 0xd,  /* Control Register D */
  33         MSM6242_CE              = 0xe,  /* Control Register E */
  34         MSM6242_CF              = 0xf,  /* Control Register F */
  35 };
  36
  37 #define MSM6242_HOUR10_AM       (0 << 2)
  38 #define MSM6242_HOUR10_PM       (1 << 2)
  39 #define MSM6242_HOUR10_HR_MASK  (3 << 0)
  40
  41 #define MSM6242_WEEK_SUNDAY     0
  42 #define MSM6242_WEEK_MONDAY     1
  43 #define MSM6242_WEEK_TUESDAY    2
  44 #define MSM6242_WEEK_WEDNESDAY  3
  45 #define MSM6242_WEEK_THURSDAY   4
  46 #define MSM6242_WEEK_FRIDAY     5
  47 #define MSM6242_WEEK_SATURDAY   6
  48
  49 #define MSM6242_CD_30_S_ADJ     (1 << 3)        /* 30-second adjustment */
  50 #define MSM6242_CD_IRQ_FLAG     (1 << 2)
  51 #define MSM6242_CD_BUSY         (1 << 1)
  52 #define MSM6242_CD_HOLD         (1 << 0)
  53
  54 #define MSM6242_CE_T_MASK       (3 << 2)
  55 #define MSM6242_CE_T_64HZ       (0 << 2)        /* period 1/64 second */
  56 #define MSM6242_CE_T_1HZ        (1 << 2)        /* period 1 second */
  57 #define MSM6242_CE_T_1MINUTE    (2 << 2)        /* period 1 minute */
  58 #define MSM6242_CE_T_1HOUR      (3 << 2)        /* period 1 hour */
  59
  60 #define MSM6242_CE_ITRPT_STND   (1 << 1)
  61 #define MSM6242_CE_MASK         (1 << 0)        /* STD.P output control */
  62
  63 #define MSM6242_CF_TEST         (1 << 3)
  64 #define MSM6242_CF_12H          (0 << 2)
  65 #define MSM6242_CF_24H          (1 << 2)
  66 #define MSM6242_CF_STOP         (1 << 1)
  67 #define MSM6242_CF_REST         (1 << 0)        /* reset */
  68
  69
  70 struct msm6242_priv {
  71         u32 __iomem *regs;
  72         struct rtc_device *rtc;
  73 };
  74
  75 static inline unsigned int msm6242_read(struct msm6242_priv *priv,
  76                                        unsigned int reg)
  77 {
  78         return __raw_readl(&priv->regs[reg]) & 0xf;
  79 }
  80
  81 static inline void msm6242_write(struct msm6242_priv *priv, unsigned int val,
  82                                 unsigned int reg)
  83 {
  84         return __raw_writel(val, &priv->regs[reg]);
  85 }
  86
  87 static inline void msm6242_set(struct msm6242_priv *priv, unsigned int val,
  88                                unsigned int reg)
  89 {
  90         msm6242_write(priv, msm6242_read(priv, reg) | val, reg);
  91 }
  92
  93 static inline void msm6242_clear(struct msm6242_priv *priv, unsigned int val,
  94                                  unsigned int reg)
  95 {
  96         msm6242_write(priv, msm6242_read(priv, reg) & ~val, reg);
  97 }
  98
  99 static void msm6242_lock(struct msm6242_priv *priv)
 100 {
 101         int cnt = 5;
 102
 103         msm6242_set(priv, MSM6242_CD_HOLD, MSM6242_CD);
 104
 105         while ((msm6242_read(priv, MSM6242_CD) & MSM6242_CD_BUSY) && cnt) {
 106                 msm6242_clear(priv, MSM6242_CD_HOLD, MSM6242_CD);
 107                 udelay(70);
 108                 msm6242_set(priv, MSM6242_CD_HOLD, MSM6242_CD);
 109                 cnt--;
 110         }
 111
 112         if (!cnt)
 113                 pr_warning("msm6242: timed out waiting for RTC (0x%x)\n",
 114                            msm6242_read(priv, MSM6242_CD));
 115 }
 116
 117 static void msm6242_unlock(struct msm6242_priv *priv)
 118 {
 119         msm6242_clear(priv, MSM6242_CD_HOLD, MSM6242_CD);
 120 }
 121
 122 static int msm6242_read_time(struct device *dev, struct rtc_time *tm)
 123 {
 124         struct msm6242_priv *priv = dev_get_drvdata(dev);
 125
 126         msm6242_lock(priv);
 127
 128         tm->tm_sec  = msm6242_read(priv, MSM6242_SECOND10) * 10 +
 129                       msm6242_read(priv, MSM6242_SECOND1);
 130         tm->tm_min  = msm6242_read(priv, MSM6242_MINUTE10) * 10 +
 131                       msm6242_read(priv, MSM6242_MINUTE1);
 132         tm->tm_hour = (msm6242_read(priv, MSM6242_HOUR10 & 3)) * 10 +
 133                       msm6242_read(priv, MSM6242_HOUR1);
 134         tm->tm_mday = msm6242_read(priv, MSM6242_DAY10) * 10 +
 135                       msm6242_read(priv, MSM6242_DAY1);
 136         tm->tm_wday = msm6242_read(priv, MSM6242_WEEK);
 137         tm->tm_mon  = msm6242_read(priv, MSM6242_MONTH10) * 10 +
 138                       msm6242_read(priv, MSM6242_MONTH1) - 1;
 139         tm->tm_year = msm6242_read(priv, MSM6242_YEAR10) * 10 +
 140                       msm6242_read(priv, MSM6242_YEAR1);
 141         if (tm->tm_year <= 69)
 142                 tm->tm_year += 100;
 143
 144         if (!(msm6242_read(priv, MSM6242_CF) & MSM6242_CF_24H)) {
 145                 unsigned int pm = msm6242_read(priv, MSM6242_HOUR10) &
 146                                   MSM6242_HOUR10_PM;
 147                 if (!pm && tm->tm_hour == 12)
 148                         tm->tm_hour = 0;
 149                 else if (pm && tm->tm_hour != 12)
 150                         tm->tm_hour += 12;
 151         }
 152
 153         msm6242_unlock(priv);
 154
 155         return rtc_valid_tm(tm);
 156 }
 157
 158 static int msm6242_set_time(struct device *dev, struct rtc_time *tm)
 159 {
 160         struct msm6242_priv *priv = dev_get_drvdata(dev);
 161
 162         msm6242_lock(priv);
 163
 164         msm6242_write(priv, tm->tm_sec / 10, MSM6242_SECOND10);
 165         msm6242_write(priv, tm->tm_sec % 10, MSM6242_SECOND1);
 166         msm6242_write(priv, tm->tm_min / 10, MSM6242_MINUTE10);
 167         msm6242_write(priv, tm->tm_min % 10, MSM6242_MINUTE1);
 168         if (msm6242_read(priv, MSM6242_CF) & MSM6242_CF_24H)
 169                 msm6242_write(priv, tm->tm_hour / 10, MSM6242_HOUR10);
 170         else if (tm->tm_hour >= 12)
 171                 msm6242_write(priv, MSM6242_HOUR10_PM + (tm->tm_hour - 12) / 10,
 172                               MSM6242_HOUR10);
 173         else
 174                 msm6242_write(priv, tm->tm_hour / 10, MSM6242_HOUR10);
 175         msm6242_write(priv, tm->tm_hour % 10, MSM6242_HOUR1);
 176         msm6242_write(priv, tm->tm_mday / 10, MSM6242_DAY10);
 177         msm6242_write(priv, tm->tm_mday % 10, MSM6242_DAY1);
 178         if (tm->tm_wday != -1)
 179                 msm6242_write(priv, tm->tm_wday, MSM6242_WEEK);
 180         msm6242_write(priv, (tm->tm_mon + 1) / 10, MSM6242_MONTH10);
 181         msm6242_write(priv, (tm->tm_mon + 1) % 10, MSM6242_MONTH1);
 182         if (tm->tm_year >= 100)
 183                 tm->tm_year -= 100;
 184         msm6242_write(priv, tm->tm_year / 10, MSM6242_YEAR10);
 185         msm6242_write(priv, tm->tm_year % 10, MSM6242_YEAR1);
 186
 187         msm6242_unlock(priv);
 188         return 0;
 189 }
 190
 191 static const struct rtc_class_ops msm6242_rtc_ops = {
 192         .read_time      = msm6242_read_time,
 193         .set_time       = msm6242_set_time,
 194 };
 195
 196 static int __init msm6242_rtc_probe(struct platform_device *dev)
 197 {
 198         struct resource *res;
 199         struct msm6242_priv *priv;
 200         struct rtc_device *rtc;
 201         int error;
 202
 203         res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 204         if (!res)
 205                 return -ENODEV;
 206
 207         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 208         if (!priv)
 209                 return -ENOMEM;
 210
 211         priv->regs = ioremap(res->start, resource_size(res));
 212         if (!priv->regs) {
 213                 error = -ENOMEM;
 214                 goto out_free_priv;
 215         }
 216
 217         rtc = rtc_device_register("rtc-msm6242", &dev->dev, &msm6242_rtc_ops,
 218                                   THIS_MODULE);
 219         if (IS_ERR(rtc)) {
 220                 error = PTR_ERR(rtc);
 221                 goto out_unmap;
 222         }
 223
 224         priv->rtc = rtc;
 225         platform_set_drvdata(dev, priv);
 226         return 0;
 227
 228 out_unmap:
 229         iounmap(priv->regs);
 230 out_free_priv:
 231         kfree(priv);
 232         return error;
 233 }
 234
 235 static int __exit msm6242_rtc_remove(struct platform_device *dev)
 236 {
 237         struct msm6242_priv *priv = platform_get_drvdata(dev);
 238
 239         rtc_device_unregister(priv->rtc);
 240         iounmap(priv->regs);
 241         kfree(priv);
 242         return 0;
 243 }
 244
 245 static struct platform_driver msm6242_rtc_driver = {
 246         .driver = {
 247                 .name   = "rtc-msm6242",
 248                 .owner  = THIS_MODULE,
 249         },
 250         .remove = __exit_p(msm6242_rtc_remove),
 251 };
 252
 253 static int __init msm6242_rtc_init(void)
 254 {
 255         return platform_driver_probe(&msm6242_rtc_driver, msm6242_rtc_probe);
 256 }
 257
 258 static void __exit msm6242_rtc_fini(void)
 259 {
 260         platform_driver_unregister(&msm6242_rtc_driver);
 261 }
 262
 263 module_init(msm6242_rtc_init);
 264 module_exit(msm6242_rtc_fini);
 265
 266 MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
 267 MODULE_LICENSE("GPL");
 268 MODULE_DESCRIPTION("Oki MSM6242 RTC driver");
 269 MODULE_ALIAS("platform:rtc-msm6242");