LXR linux/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
  21enum {
  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
  73struct msm6242_priv {
  74        u32 __iomem *regs;
  75        struct rtc_device *rtc;
  76};
  77
  78static inline unsigned int msm6242_read(struct msm6242_priv *priv,
  79                                       unsigned int reg)
  80{
  81        return __raw_readl(&priv->regs[reg]) & 0xf;
  82}
  83
  84static 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
  90static 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
  96static 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
 102static 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
 120static void msm6242_unlock(struct msm6242_priv *priv)
 121{
 122        msm6242_clear(priv, MSM6242_CD_HOLD, MSM6242_CD);
 123}
 124
 125static 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 rtc_valid_tm(tm);
 159}
 160
 161static 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
 194static const struct rtc_class_ops msm6242_rtc_ops = {
 195        .read_time      = msm6242_read_time,
 196        .set_time       = msm6242_set_time,
 197};
 198
 199static 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
 227static struct platform_driver msm6242_rtc_driver = {
 228        .driver = {
 229                .name   = "rtc-msm6242",
 230        },
 231};
 232
 233module_platform_driver_probe(msm6242_rtc_driver, msm6242_rtc_probe);
 234
 235MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
 236MODULE_LICENSE("GPL");
 237MODULE_DESCRIPTION("Oki MSM6242 RTC driver");
 238MODULE_ALIAS("platform:rtc-msm6242");
 239