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