linux/drivers/rtc/rtc-msm6242.c
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   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#include <linux/slab.h>
  17
  18
  19enum {
  20        MSM6242_SECOND1         = 0x0,  /* 1-second digit register */
  21        MSM6242_SECOND10        = 0x1,  /* 10-second digit register */
  22        MSM6242_MINUTE1         = 0x2,  /* 1-minute digit register */
  23        MSM6242_MINUTE10        = 0x3,  /* 10-minute digit register */
  24        MSM6242_HOUR1           = 0x4,  /* 1-hour digit register */
  25        MSM6242_HOUR10          = 0x5,  /* PM/AM, 10-hour digit register */
  26        MSM6242_DAY1            = 0x6,  /* 1-day digit register */
  27        MSM6242_DAY10           = 0x7,  /* 10-day digit register */
  28        MSM6242_MONTH1          = 0x8,  /* 1-month digit register */
  29        MSM6242_MONTH10         = 0x9,  /* 10-month digit register */
  30        MSM6242_YEAR1           = 0xa,  /* 1-year digit register */
  31        MSM6242_YEAR10          = 0xb,  /* 10-year digit register */
  32        MSM6242_WEEK            = 0xc,  /* Week register */
  33        MSM6242_CD              = 0xd,  /* Control Register D */
  34        MSM6242_CE              = 0xe,  /* Control Register E */
  35        MSM6242_CF              = 0xf,  /* Control Register F */
  36};
  37
  38#define MSM6242_HOUR10_AM       (0 << 2)
  39#define MSM6242_HOUR10_PM       (1 << 2)
  40#define MSM6242_HOUR10_HR_MASK  (3 << 0)
  41
  42#define MSM6242_WEEK_SUNDAY     0
  43#define MSM6242_WEEK_MONDAY     1
  44#define MSM6242_WEEK_TUESDAY    2
  45#define MSM6242_WEEK_WEDNESDAY  3
  46#define MSM6242_WEEK_THURSDAY   4
  47#define MSM6242_WEEK_FRIDAY     5
  48#define MSM6242_WEEK_SATURDAY   6
  49
  50#define MSM6242_CD_30_S_ADJ     (1 << 3)        /* 30-second adjustment */
  51#define MSM6242_CD_IRQ_FLAG     (1 << 2)
  52#define MSM6242_CD_BUSY         (1 << 1)
  53#define MSM6242_CD_HOLD         (1 << 0)
  54
  55#define MSM6242_CE_T_MASK       (3 << 2)
  56#define MSM6242_CE_T_64HZ       (0 << 2)        /* period 1/64 second */
  57#define MSM6242_CE_T_1HZ        (1 << 2)        /* period 1 second */
  58#define MSM6242_CE_T_1MINUTE    (2 << 2)        /* period 1 minute */
  59#define MSM6242_CE_T_1HOUR      (3 << 2)        /* period 1 hour */
  60
  61#define MSM6242_CE_ITRPT_STND   (1 << 1)
  62#define MSM6242_CE_MASK         (1 << 0)        /* STD.P output control */
  63
  64#define MSM6242_CF_TEST         (1 << 3)
  65#define MSM6242_CF_12H          (0 << 2)
  66#define MSM6242_CF_24H          (1 << 2)
  67#define MSM6242_CF_STOP         (1 << 1)
  68#define MSM6242_CF_REST         (1 << 0)        /* reset */
  69
  70
  71struct msm6242_priv {
  72        u32 __iomem *regs;
  73        struct rtc_device *rtc;
  74};
  75
  76static inline unsigned int msm6242_read(struct msm6242_priv *priv,
  77                                       unsigned int reg)
  78{
  79        return __raw_readl(&priv->regs[reg]) & 0xf;
  80}
  81
  82static inline void msm6242_write(struct msm6242_priv *priv, unsigned int val,
  83                                unsigned int reg)
  84{
  85        __raw_writel(val, &priv->regs[reg]);
  86}
  87
  88static inline void msm6242_set(struct msm6242_priv *priv, unsigned int val,
  89                               unsigned int reg)
  90{
  91        msm6242_write(priv, msm6242_read(priv, reg) | val, reg);
  92}
  93
  94static inline void msm6242_clear(struct msm6242_priv *priv, unsigned int val,
  95                                 unsigned int reg)
  96{
  97        msm6242_write(priv, msm6242_read(priv, reg) & ~val, reg);
  98}
  99
 100static void msm6242_lock(struct msm6242_priv *priv)
 101{
 102        int cnt = 5;
 103
 104        msm6242_set(priv, MSM6242_CD_HOLD, MSM6242_CD);
 105
 106        while ((msm6242_read(priv, MSM6242_CD) & MSM6242_CD_BUSY) && cnt) {
 107                msm6242_clear(priv, MSM6242_CD_HOLD, MSM6242_CD);
 108                udelay(70);
 109                msm6242_set(priv, MSM6242_CD_HOLD, MSM6242_CD);
 110                cnt--;
 111        }
 112
 113        if (!cnt)
 114                pr_warning("msm6242: timed out waiting for RTC (0x%x)\n",
 115                           msm6242_read(priv, MSM6242_CD));
 116}
 117
 118static void msm6242_unlock(struct msm6242_priv *priv)
 119{
 120        msm6242_clear(priv, MSM6242_CD_HOLD, MSM6242_CD);
 121}
 122
 123static int msm6242_read_time(struct device *dev, struct rtc_time *tm)
 124{
 125        struct msm6242_priv *priv = dev_get_drvdata(dev);
 126
 127        msm6242_lock(priv);
 128
 129        tm->tm_sec  = msm6242_read(priv, MSM6242_SECOND10) * 10 +
 130                      msm6242_read(priv, MSM6242_SECOND1);
 131        tm->tm_min  = msm6242_read(priv, MSM6242_MINUTE10) * 10 +
 132                      msm6242_read(priv, MSM6242_MINUTE1);
 133        tm->tm_hour = (msm6242_read(priv, MSM6242_HOUR10 & 3)) * 10 +
 134                      msm6242_read(priv, MSM6242_HOUR1);
 135        tm->tm_mday = msm6242_read(priv, MSM6242_DAY10) * 10 +
 136                      msm6242_read(priv, MSM6242_DAY1);
 137        tm->tm_wday = msm6242_read(priv, MSM6242_WEEK);
 138        tm->tm_mon  = msm6242_read(priv, MSM6242_MONTH10) * 10 +
 139                      msm6242_read(priv, MSM6242_MONTH1) - 1;
 140        tm->tm_year = msm6242_read(priv, MSM6242_YEAR10) * 10 +
 141                      msm6242_read(priv, MSM6242_YEAR1);
 142        if (tm->tm_year <= 69)
 143                tm->tm_year += 100;
 144
 145        if (!(msm6242_read(priv, MSM6242_CF) & MSM6242_CF_24H)) {
 146                unsigned int pm = msm6242_read(priv, MSM6242_HOUR10) &
 147                                  MSM6242_HOUR10_PM;
 148                if (!pm && tm->tm_hour == 12)
 149                        tm->tm_hour = 0;
 150                else if (pm && tm->tm_hour != 12)
 151                        tm->tm_hour += 12;
 152        }
 153
 154        msm6242_unlock(priv);
 155
 156        return rtc_valid_tm(tm);
 157}
 158
 159static int msm6242_set_time(struct device *dev, struct rtc_time *tm)
 160{
 161        struct msm6242_priv *priv = dev_get_drvdata(dev);
 162
 163        msm6242_lock(priv);
 164
 165        msm6242_write(priv, tm->tm_sec / 10, MSM6242_SECOND10);
 166        msm6242_write(priv, tm->tm_sec % 10, MSM6242_SECOND1);
 167        msm6242_write(priv, tm->tm_min / 10, MSM6242_MINUTE10);
 168        msm6242_write(priv, tm->tm_min % 10, MSM6242_MINUTE1);
 169        if (msm6242_read(priv, MSM6242_CF) & MSM6242_CF_24H)
 170                msm6242_write(priv, tm->tm_hour / 10, MSM6242_HOUR10);
 171        else if (tm->tm_hour >= 12)
 172                msm6242_write(priv, MSM6242_HOUR10_PM + (tm->tm_hour - 12) / 10,
 173                              MSM6242_HOUR10);
 174        else
 175                msm6242_write(priv, tm->tm_hour / 10, MSM6242_HOUR10);
 176        msm6242_write(priv, tm->tm_hour % 10, MSM6242_HOUR1);
 177        msm6242_write(priv, tm->tm_mday / 10, MSM6242_DAY10);
 178        msm6242_write(priv, tm->tm_mday % 10, MSM6242_DAY1);
 179        if (tm->tm_wday != -1)
 180                msm6242_write(priv, tm->tm_wday, MSM6242_WEEK);
 181        msm6242_write(priv, (tm->tm_mon + 1) / 10, MSM6242_MONTH10);
 182        msm6242_write(priv, (tm->tm_mon + 1) % 10, MSM6242_MONTH1);
 183        if (tm->tm_year >= 100)
 184                tm->tm_year -= 100;
 185        msm6242_write(priv, tm->tm_year / 10, MSM6242_YEAR10);
 186        msm6242_write(priv, tm->tm_year % 10, MSM6242_YEAR1);
 187
 188        msm6242_unlock(priv);
 189        return 0;
 190}
 191
 192static const struct rtc_class_ops msm6242_rtc_ops = {
 193        .read_time      = msm6242_read_time,
 194        .set_time       = msm6242_set_time,
 195};
 196
 197static int __init msm6242_rtc_probe(struct platform_device *dev)
 198{
 199        struct resource *res;
 200        struct msm6242_priv *priv;
 201        struct rtc_device *rtc;
 202        int error;
 203
 204        res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 205        if (!res)
 206                return -ENODEV;
 207
 208        priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 209        if (!priv)
 210                return -ENOMEM;
 211
 212        priv->regs = ioremap(res->start, resource_size(res));
 213        if (!priv->regs) {
 214                error = -ENOMEM;
 215                goto out_free_priv;
 216        }
 217        platform_set_drvdata(dev, priv);
 218
 219        rtc = rtc_device_register("rtc-msm6242", &dev->dev, &msm6242_rtc_ops,
 220                                  THIS_MODULE);
 221        if (IS_ERR(rtc)) {
 222                error = PTR_ERR(rtc);
 223                goto out_unmap;
 224        }
 225
 226        priv->rtc = rtc;
 227        return 0;
 228
 229out_unmap:
 230        platform_set_drvdata(dev, NULL);
 231        iounmap(priv->regs);
 232out_free_priv:
 233        kfree(priv);
 234        return error;
 235}
 236
 237static int __exit msm6242_rtc_remove(struct platform_device *dev)
 238{
 239        struct msm6242_priv *priv = platform_get_drvdata(dev);
 240
 241        rtc_device_unregister(priv->rtc);
 242        iounmap(priv->regs);
 243        kfree(priv);
 244        return 0;
 245}
 246
 247static struct platform_driver msm6242_rtc_driver = {
 248        .driver = {
 249                .name   = "rtc-msm6242",
 250                .owner  = THIS_MODULE,
 251        },
 252        .remove = __exit_p(msm6242_rtc_remove),
 253};
 254
 255static int __init msm6242_rtc_init(void)
 256{
 257        return platform_driver_probe(&msm6242_rtc_driver, msm6242_rtc_probe);
 258}
 259
 260static void __exit msm6242_rtc_fini(void)
 261{
 262        platform_driver_unregister(&msm6242_rtc_driver);
 263}
 264
 265module_init(msm6242_rtc_init);
 266module_exit(msm6242_rtc_fini);
 267
 268MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
 269MODULE_LICENSE("GPL");
 270MODULE_DESCRIPTION("Oki MSM6242 RTC driver");
 271MODULE_ALIAS("platform:rtc-msm6242");
 272
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