drivers/rtc/rtc-nuc900.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2008-2009 Nuvoton technology corporation.
   4  *
   5  * Wan ZongShun <mcuos.com@gmail.com>
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/init.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/slab.h>
  12 #include <linux/rtc.h>
  13 #include <linux/delay.h>
  14 #include <linux/io.h>
  15 #include <linux/bcd.h>
  16
  17 /* RTC Control Registers */
  18 #define REG_RTC_INIR            0x00
  19 #define REG_RTC_AER             0x04
  20 #define REG_RTC_FCR             0x08
  21 #define REG_RTC_TLR             0x0C
  22 #define REG_RTC_CLR             0x10
  23 #define REG_RTC_TSSR            0x14
  24 #define REG_RTC_DWR             0x18
  25 #define REG_RTC_TAR             0x1C
  26 #define REG_RTC_CAR             0x20
  27 #define REG_RTC_LIR             0x24
  28 #define REG_RTC_RIER            0x28
  29 #define REG_RTC_RIIR            0x2C
  30 #define REG_RTC_TTR             0x30
  31
  32 #define RTCSET                  0x01
  33 #define AERRWENB                0x10000
  34 #define INIRRESET               0xa5eb1357
  35 #define AERPOWERON              0xA965
  36 #define AERPOWEROFF             0x0000
  37 #define LEAPYEAR                0x0001
  38 #define TICKENB                 0x80
  39 #define TICKINTENB              0x0002
  40 #define ALARMINTENB             0x0001
  41 #define MODE24                  0x0001
  42
  43 struct nuc900_rtc {
  44         int                     irq_num;
  45         void __iomem            *rtc_reg;
  46         struct rtc_device       *rtcdev;
  47 };
  48
  49 struct nuc900_bcd_time {
  50         int bcd_sec;
  51         int bcd_min;
  52         int bcd_hour;
  53         int bcd_mday;
  54         int bcd_mon;
  55         int bcd_year;
  56 };
  57
  58 static irqreturn_t nuc900_rtc_interrupt(int irq, void *_rtc)
  59 {
  60         struct nuc900_rtc *rtc = _rtc;
  61         unsigned long events = 0, rtc_irq;
  62
  63         rtc_irq = __raw_readl(rtc->rtc_reg + REG_RTC_RIIR);
  64
  65         if (rtc_irq & ALARMINTENB) {
  66                 rtc_irq &= ~ALARMINTENB;
  67                 __raw_writel(rtc_irq, rtc->rtc_reg + REG_RTC_RIIR);
  68                 events |= RTC_AF | RTC_IRQF;
  69         }
  70
  71         if (rtc_irq & TICKINTENB) {
  72                 rtc_irq &= ~TICKINTENB;
  73                 __raw_writel(rtc_irq, rtc->rtc_reg + REG_RTC_RIIR);
  74                 events |= RTC_UF | RTC_IRQF;
  75         }
  76
  77         rtc_update_irq(rtc->rtcdev, 1, events);
  78
  79         return IRQ_HANDLED;
  80 }
  81
  82 static int *check_rtc_access_enable(struct nuc900_rtc *nuc900_rtc)
  83 {
  84         unsigned int timeout = 0x1000;
  85         __raw_writel(INIRRESET, nuc900_rtc->rtc_reg + REG_RTC_INIR);
  86
  87         mdelay(10);
  88
  89         __raw_writel(AERPOWERON, nuc900_rtc->rtc_reg + REG_RTC_AER);
  90
  91         while (!(__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_AER) & AERRWENB)
  92                                                                 && --timeout)
  93                 mdelay(1);
  94
  95         if (!timeout)
  96                 return ERR_PTR(-EPERM);
  97
  98         return NULL;
  99 }
 100
 101 static void nuc900_rtc_bcd2bin(unsigned int timereg,
 102                                unsigned int calreg, struct rtc_time *tm)
 103 {
 104         tm->tm_mday     = bcd2bin(calreg >> 0);
 105         tm->tm_mon      = bcd2bin(calreg >> 8);
 106         tm->tm_year     = bcd2bin(calreg >> 16) + 100;
 107
 108         tm->tm_sec      = bcd2bin(timereg >> 0);
 109         tm->tm_min      = bcd2bin(timereg >> 8);
 110         tm->tm_hour     = bcd2bin(timereg >> 16);
 111 }
 112
 113 static void nuc900_rtc_bin2bcd(struct device *dev, struct rtc_time *settm,
 114                                                 struct nuc900_bcd_time *gettm)
 115 {
 116         gettm->bcd_mday = bin2bcd(settm->tm_mday) << 0;
 117         gettm->bcd_mon  = bin2bcd(settm->tm_mon) << 8;
 118
 119         if (settm->tm_year < 100) {
 120                 dev_warn(dev, "The year will be between 1970-1999, right?\n");
 121                 gettm->bcd_year = bin2bcd(settm->tm_year) << 16;
 122         } else {
 123                 gettm->bcd_year = bin2bcd(settm->tm_year - 100) << 16;
 124         }
 125
 126         gettm->bcd_sec  = bin2bcd(settm->tm_sec) << 0;
 127         gettm->bcd_min  = bin2bcd(settm->tm_min) << 8;
 128         gettm->bcd_hour = bin2bcd(settm->tm_hour) << 16;
 129 }
 130
 131 static int nuc900_alarm_irq_enable(struct device *dev, unsigned int enabled)
 132 {
 133         struct nuc900_rtc *rtc = dev_get_drvdata(dev);
 134
 135         if (enabled)
 136                 __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)|
 137                                 (ALARMINTENB), rtc->rtc_reg + REG_RTC_RIER);
 138         else
 139                 __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)&
 140                                 (~ALARMINTENB), rtc->rtc_reg + REG_RTC_RIER);
 141
 142         return 0;
 143 }
 144
 145 static int nuc900_rtc_read_time(struct device *dev, struct rtc_time *tm)
 146 {
 147         struct nuc900_rtc *rtc = dev_get_drvdata(dev);
 148         unsigned int timeval, clrval;
 149
 150         timeval = __raw_readl(rtc->rtc_reg + REG_RTC_TLR);
 151         clrval  = __raw_readl(rtc->rtc_reg + REG_RTC_CLR);
 152
 153         nuc900_rtc_bcd2bin(timeval, clrval, tm);
 154
 155         return 0;
 156 }
 157
 158 static int nuc900_rtc_set_time(struct device *dev, struct rtc_time *tm)
 159 {
 160         struct nuc900_rtc *rtc = dev_get_drvdata(dev);
 161         struct nuc900_bcd_time gettm;
 162         unsigned long val;
 163         int *err;
 164
 165         nuc900_rtc_bin2bcd(dev, tm, &gettm);
 166
 167         err = check_rtc_access_enable(rtc);
 168         if (IS_ERR(err))
 169                 return PTR_ERR(err);
 170
 171         val = gettm.bcd_mday | gettm.bcd_mon | gettm.bcd_year;
 172         __raw_writel(val, rtc->rtc_reg + REG_RTC_CLR);
 173
 174         val = gettm.bcd_sec | gettm.bcd_min | gettm.bcd_hour;
 175         __raw_writel(val, rtc->rtc_reg + REG_RTC_TLR);
 176
 177         return 0;
 178 }
 179
 180 static int nuc900_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 181 {
 182         struct nuc900_rtc *rtc = dev_get_drvdata(dev);
 183         unsigned int timeval, carval;
 184
 185         timeval = __raw_readl(rtc->rtc_reg + REG_RTC_TAR);
 186         carval  = __raw_readl(rtc->rtc_reg + REG_RTC_CAR);
 187
 188         nuc900_rtc_bcd2bin(timeval, carval, &alrm->time);
 189
 190         return rtc_valid_tm(&alrm->time);
 191 }
 192
 193 static int nuc900_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 194 {
 195         struct nuc900_rtc *rtc = dev_get_drvdata(dev);
 196         struct nuc900_bcd_time tm;
 197         unsigned long val;
 198         int *err;
 199
 200         nuc900_rtc_bin2bcd(dev, &alrm->time, &tm);
 201
 202         err = check_rtc_access_enable(rtc);
 203         if (IS_ERR(err))
 204                 return PTR_ERR(err);
 205
 206         val = tm.bcd_mday | tm.bcd_mon | tm.bcd_year;
 207         __raw_writel(val, rtc->rtc_reg + REG_RTC_CAR);
 208
 209         val = tm.bcd_sec | tm.bcd_min | tm.bcd_hour;
 210         __raw_writel(val, rtc->rtc_reg + REG_RTC_TAR);
 211
 212         return 0;
 213 }
 214
 215 static const struct rtc_class_ops nuc900_rtc_ops = {
 216         .read_time = nuc900_rtc_read_time,
 217         .set_time = nuc900_rtc_set_time,
 218         .read_alarm = nuc900_rtc_read_alarm,
 219         .set_alarm = nuc900_rtc_set_alarm,
 220         .alarm_irq_enable = nuc900_alarm_irq_enable,
 221 };
 222
 223 static int __init nuc900_rtc_probe(struct platform_device *pdev)
 224 {
 225         struct resource *res;
 226         struct nuc900_rtc *nuc900_rtc;
 227
 228         nuc900_rtc = devm_kzalloc(&pdev->dev, sizeof(struct nuc900_rtc),
 229                                 GFP_KERNEL);
 230         if (!nuc900_rtc)
 231                 return -ENOMEM;
 232
 233         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 234         nuc900_rtc->rtc_reg = devm_ioremap_resource(&pdev->dev, res);
 235         if (IS_ERR(nuc900_rtc->rtc_reg))
 236                 return PTR_ERR(nuc900_rtc->rtc_reg);
 237
 238         platform_set_drvdata(pdev, nuc900_rtc);
 239
 240         nuc900_rtc->rtcdev = devm_rtc_device_register(&pdev->dev, pdev->name,
 241                                                 &nuc900_rtc_ops, THIS_MODULE);
 242         if (IS_ERR(nuc900_rtc->rtcdev)) {
 243                 dev_err(&pdev->dev, "rtc device register failed\n");
 244                 return PTR_ERR(nuc900_rtc->rtcdev);
 245         }
 246
 247         __raw_writel(__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_TSSR) | MODE24,
 248                                         nuc900_rtc->rtc_reg + REG_RTC_TSSR);
 249
 250         nuc900_rtc->irq_num = platform_get_irq(pdev, 0);
 251         if (devm_request_irq(&pdev->dev, nuc900_rtc->irq_num,
 252                         nuc900_rtc_interrupt, 0, "nuc900rtc", nuc900_rtc)) {
 253                 dev_err(&pdev->dev, "NUC900 RTC request irq failed\n");
 254                 return -EBUSY;
 255         }
 256
 257         return 0;
 258 }
 259
 260 static struct platform_driver nuc900_rtc_driver = {
 261         .driver         = {
 262                 .name   = "nuc900-rtc",
 263         },
 264 };
 265
 266 module_platform_driver_probe(nuc900_rtc_driver, nuc900_rtc_probe);
 267
 268 MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
 269 MODULE_DESCRIPTION("nuc910/nuc920 RTC driver");
 270 MODULE_LICENSE("GPL");
 271 MODULE_ALIAS("platform:nuc900-rtc");