drivers/rtc/rtc-nuc900.c

   1 /*
   2  * Copyright (c) 2008-2009 Nuvoton technology corporation.
   3  *
   4  * Wan ZongShun <mcuos.com@gmail.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation;version 2 of the License.
   9  *
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/slab.h>
  16 #include <linux/rtc.h>
  17 #include <linux/delay.h>
  18 #include <linux/io.h>
  19 #include <linux/bcd.h>
  20
  21 /* RTC Control Registers */
  22 #define REG_RTC_INIR            0x00
  23 #define REG_RTC_AER             0x04
  24 #define REG_RTC_FCR             0x08
  25 #define REG_RTC_TLR             0x0C
  26 #define REG_RTC_CLR             0x10
  27 #define REG_RTC_TSSR            0x14
  28 #define REG_RTC_DWR             0x18
  29 #define REG_RTC_TAR             0x1C
  30 #define REG_RTC_CAR             0x20
  31 #define REG_RTC_LIR             0x24
  32 #define REG_RTC_RIER            0x28
  33 #define REG_RTC_RIIR            0x2C
  34 #define REG_RTC_TTR             0x30
  35
  36 #define RTCSET                  0x01
  37 #define AERRWENB                0x10000
  38 #define INIRRESET               0xa5eb1357
  39 #define AERPOWERON              0xA965
  40 #define AERPOWEROFF             0x0000
  41 #define LEAPYEAR                0x0001
  42 #define TICKENB                 0x80
  43 #define TICKINTENB              0x0002
  44 #define ALARMINTENB             0x0001
  45 #define MODE24                  0x0001
  46
  47 struct nuc900_rtc {
  48         int                     irq_num;
  49         void __iomem            *rtc_reg;
  50         struct rtc_device       *rtcdev;
  51 };
  52
  53 struct nuc900_bcd_time {
  54         int bcd_sec;
  55         int bcd_min;
  56         int bcd_hour;
  57         int bcd_mday;
  58         int bcd_mon;
  59         int bcd_year;
  60 };
  61
  62 static irqreturn_t nuc900_rtc_interrupt(int irq, void *_rtc)
  63 {
  64         struct nuc900_rtc *rtc = _rtc;
  65         unsigned long events = 0, rtc_irq;
  66
  67         rtc_irq = __raw_readl(rtc->rtc_reg + REG_RTC_RIIR);
  68
  69         if (rtc_irq & ALARMINTENB) {
  70                 rtc_irq &= ~ALARMINTENB;
  71                 __raw_writel(rtc_irq, rtc->rtc_reg + REG_RTC_RIIR);
  72                 events |= RTC_AF | RTC_IRQF;
  73         }
  74
  75         if (rtc_irq & TICKINTENB) {
  76                 rtc_irq &= ~TICKINTENB;
  77                 __raw_writel(rtc_irq, rtc->rtc_reg + REG_RTC_RIIR);
  78                 events |= RTC_UF | RTC_IRQF;
  79         }
  80
  81         rtc_update_irq(rtc->rtcdev, 1, events);
  82
  83         return IRQ_HANDLED;
  84 }
  85
  86 static int *check_rtc_access_enable(struct nuc900_rtc *nuc900_rtc)
  87 {
  88         unsigned int timeout = 0x1000;
  89         __raw_writel(INIRRESET, nuc900_rtc->rtc_reg + REG_RTC_INIR);
  90
  91         mdelay(10);
  92
  93         __raw_writel(AERPOWERON, nuc900_rtc->rtc_reg + REG_RTC_AER);
  94
  95         while (!(__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_AER) & AERRWENB)
  96                                                                 && --timeout)
  97                 mdelay(1);
  98
  99         if (!timeout)
 100                 return ERR_PTR(-EPERM);
 101
 102         return NULL;
 103 }
 104
 105 static void nuc900_rtc_bcd2bin(unsigned int timereg,
 106                                unsigned int calreg, struct rtc_time *tm)
 107 {
 108         tm->tm_mday     = bcd2bin(calreg >> 0);
 109         tm->tm_mon      = bcd2bin(calreg >> 8);
 110         tm->tm_year     = bcd2bin(calreg >> 16) + 100;
 111
 112         tm->tm_sec      = bcd2bin(timereg >> 0);
 113         tm->tm_min      = bcd2bin(timereg >> 8);
 114         tm->tm_hour     = bcd2bin(timereg >> 16);
 115 }
 116
 117 static void nuc900_rtc_bin2bcd(struct device *dev, struct rtc_time *settm,
 118                                                 struct nuc900_bcd_time *gettm)
 119 {
 120         gettm->bcd_mday = bin2bcd(settm->tm_mday) << 0;
 121         gettm->bcd_mon  = bin2bcd(settm->tm_mon) << 8;
 122
 123         if (settm->tm_year < 100) {
 124                 dev_warn(dev, "The year will be between 1970-1999, right?\n");
 125                 gettm->bcd_year = bin2bcd(settm->tm_year) << 16;
 126         } else {
 127                 gettm->bcd_year = bin2bcd(settm->tm_year - 100) << 16;
 128         }
 129
 130         gettm->bcd_sec  = bin2bcd(settm->tm_sec) << 0;
 131         gettm->bcd_min  = bin2bcd(settm->tm_min) << 8;
 132         gettm->bcd_hour = bin2bcd(settm->tm_hour) << 16;
 133 }
 134
 135 static int nuc900_alarm_irq_enable(struct device *dev, unsigned int enabled)
 136 {
 137         struct nuc900_rtc *rtc = dev_get_drvdata(dev);
 138
 139         if (enabled)
 140                 __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)|
 141                                 (ALARMINTENB), rtc->rtc_reg + REG_RTC_RIER);
 142         else
 143                 __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)&
 144                                 (~ALARMINTENB), rtc->rtc_reg + REG_RTC_RIER);
 145
 146         return 0;
 147 }
 148
 149 static int nuc900_rtc_read_time(struct device *dev, struct rtc_time *tm)
 150 {
 151         struct nuc900_rtc *rtc = dev_get_drvdata(dev);
 152         unsigned int timeval, clrval;
 153
 154         timeval = __raw_readl(rtc->rtc_reg + REG_RTC_TLR);
 155         clrval  = __raw_readl(rtc->rtc_reg + REG_RTC_CLR);
 156
 157         nuc900_rtc_bcd2bin(timeval, clrval, tm);
 158
 159         return 0;
 160 }
 161
 162 static int nuc900_rtc_set_time(struct device *dev, struct rtc_time *tm)
 163 {
 164         struct nuc900_rtc *rtc = dev_get_drvdata(dev);
 165         struct nuc900_bcd_time gettm;
 166         unsigned long val;
 167         int *err;
 168
 169         nuc900_rtc_bin2bcd(dev, tm, &gettm);
 170
 171         err = check_rtc_access_enable(rtc);
 172         if (IS_ERR(err))
 173                 return PTR_ERR(err);
 174
 175         val = gettm.bcd_mday | gettm.bcd_mon | gettm.bcd_year;
 176         __raw_writel(val, rtc->rtc_reg + REG_RTC_CLR);
 177
 178         val = gettm.bcd_sec | gettm.bcd_min | gettm.bcd_hour;
 179         __raw_writel(val, rtc->rtc_reg + REG_RTC_TLR);
 180
 181         return 0;
 182 }
 183
 184 static int nuc900_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 185 {
 186         struct nuc900_rtc *rtc = dev_get_drvdata(dev);
 187         unsigned int timeval, carval;
 188
 189         timeval = __raw_readl(rtc->rtc_reg + REG_RTC_TAR);
 190         carval  = __raw_readl(rtc->rtc_reg + REG_RTC_CAR);
 191
 192         nuc900_rtc_bcd2bin(timeval, carval, &alrm->time);
 193
 194         return rtc_valid_tm(&alrm->time);
 195 }
 196
 197 static int nuc900_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 198 {
 199         struct nuc900_rtc *rtc = dev_get_drvdata(dev);
 200         struct nuc900_bcd_time tm;
 201         unsigned long val;
 202         int *err;
 203
 204         nuc900_rtc_bin2bcd(dev, &alrm->time, &tm);
 205
 206         err = check_rtc_access_enable(rtc);
 207         if (IS_ERR(err))
 208                 return PTR_ERR(err);
 209
 210         val = tm.bcd_mday | tm.bcd_mon | tm.bcd_year;
 211         __raw_writel(val, rtc->rtc_reg + REG_RTC_CAR);
 212
 213         val = tm.bcd_sec | tm.bcd_min | tm.bcd_hour;
 214         __raw_writel(val, rtc->rtc_reg + REG_RTC_TAR);
 215
 216         return 0;
 217 }
 218
 219 static const struct rtc_class_ops nuc900_rtc_ops = {
 220         .read_time = nuc900_rtc_read_time,
 221         .set_time = nuc900_rtc_set_time,
 222         .read_alarm = nuc900_rtc_read_alarm,
 223         .set_alarm = nuc900_rtc_set_alarm,
 224         .alarm_irq_enable = nuc900_alarm_irq_enable,
 225 };
 226
 227 static int __init nuc900_rtc_probe(struct platform_device *pdev)
 228 {
 229         struct resource *res;
 230         struct nuc900_rtc *nuc900_rtc;
 231
 232         nuc900_rtc = devm_kzalloc(&pdev->dev, sizeof(struct nuc900_rtc),
 233                                 GFP_KERNEL);
 234         if (!nuc900_rtc)
 235                 return -ENOMEM;
 236
 237         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 238         nuc900_rtc->rtc_reg = devm_ioremap_resource(&pdev->dev, res);
 239         if (IS_ERR(nuc900_rtc->rtc_reg))
 240                 return PTR_ERR(nuc900_rtc->rtc_reg);
 241
 242         platform_set_drvdata(pdev, nuc900_rtc);
 243
 244         nuc900_rtc->rtcdev = devm_rtc_device_register(&pdev->dev, pdev->name,
 245                                                 &nuc900_rtc_ops, THIS_MODULE);
 246         if (IS_ERR(nuc900_rtc->rtcdev)) {
 247                 dev_err(&pdev->dev, "rtc device register failed\n");
 248                 return PTR_ERR(nuc900_rtc->rtcdev);
 249         }
 250
 251         __raw_writel(__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_TSSR) | MODE24,
 252                                         nuc900_rtc->rtc_reg + REG_RTC_TSSR);
 253
 254         nuc900_rtc->irq_num = platform_get_irq(pdev, 0);
 255         if (devm_request_irq(&pdev->dev, nuc900_rtc->irq_num,
 256                         nuc900_rtc_interrupt, 0, "nuc900rtc", nuc900_rtc)) {
 257                 dev_err(&pdev->dev, "NUC900 RTC request irq failed\n");
 258                 return -EBUSY;
 259         }
 260
 261         return 0;
 262 }
 263
 264 static struct platform_driver nuc900_rtc_driver = {
 265         .driver         = {
 266                 .name   = "nuc900-rtc",
 267         },
 268 };
 269
 270 module_platform_driver_probe(nuc900_rtc_driver, nuc900_rtc_probe);
 271
 272 MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
 273 MODULE_DESCRIPTION("nuc910/nuc920 RTC driver");
 274 MODULE_LICENSE("GPL");
 275 MODULE_ALIAS("platform:nuc900-rtc");