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 i;
  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         for (i = 0; i < 1000; i++) {
  96                 if (__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_AER) & AERRWENB)
  97                         return 0;
  98         }
  99
 100         if ((__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_AER) & AERRWENB) == 0x0)
 101                 return ERR_PTR(-ENODEV);
 102
 103         return ERR_PTR(-EPERM);
 104 }
 105
 106 static void nuc900_rtc_bcd2bin(unsigned int timereg,
 107                                 unsigned int calreg, struct rtc_time *tm)
 108 {
 109         tm->tm_mday     = bcd2bin(calreg >> 0);
 110         tm->tm_mon      = bcd2bin(calreg >> 8);
 111         tm->tm_year     = bcd2bin(calreg >> 16) + 100;
 112
 113         tm->tm_sec      = bcd2bin(timereg >> 0);
 114         tm->tm_min      = bcd2bin(timereg >> 8);
 115         tm->tm_hour     = bcd2bin(timereg >> 16);
 116
 117         rtc_valid_tm(tm);
 118 }
 119
 120 static void nuc900_rtc_bin2bcd(struct rtc_time *settm,
 121                                                 struct nuc900_bcd_time *gettm)
 122 {
 123         gettm->bcd_mday = bin2bcd(settm->tm_mday) << 0;
 124         gettm->bcd_mon  = bin2bcd(settm->tm_mon) << 8;
 125         gettm->bcd_year = bin2bcd(settm->tm_year - 100) << 16;
 126
 127         gettm->bcd_sec  = bin2bcd(settm->tm_sec) << 0;
 128         gettm->bcd_min  = bin2bcd(settm->tm_min) << 8;
 129         gettm->bcd_hour = bin2bcd(settm->tm_hour) << 16;
 130 }
 131
 132 static int nuc900_update_irq_enable(struct device *dev, unsigned int enabled)
 133 {
 134         struct nuc900_rtc *rtc = dev_get_drvdata(dev);
 135
 136         if (enabled)
 137                 __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)|
 138                                 (TICKINTENB), rtc->rtc_reg + REG_RTC_RIER);
 139         else
 140                 __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)&
 141                                 (~TICKINTENB), rtc->rtc_reg + REG_RTC_RIER);
 142
 143         return 0;
 144 }
 145
 146 static int nuc900_alarm_irq_enable(struct device *dev, unsigned int enabled)
 147 {
 148         struct nuc900_rtc *rtc = dev_get_drvdata(dev);
 149
 150         if (enabled)
 151                 __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)|
 152                                 (ALARMINTENB), rtc->rtc_reg + REG_RTC_RIER);
 153         else
 154                 __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)&
 155                                 (~ALARMINTENB), rtc->rtc_reg + REG_RTC_RIER);
 156
 157         return 0;
 158 }
 159
 160 static int nuc900_rtc_read_time(struct device *dev, struct rtc_time *tm)
 161 {
 162         struct nuc900_rtc *rtc = dev_get_drvdata(dev);
 163         unsigned int timeval, clrval;
 164
 165         timeval = __raw_readl(rtc->rtc_reg + REG_RTC_TLR);
 166         clrval  = __raw_readl(rtc->rtc_reg + REG_RTC_CLR);
 167
 168         nuc900_rtc_bcd2bin(timeval, clrval, tm);
 169
 170         return 0;
 171 }
 172
 173 static int nuc900_rtc_set_time(struct device *dev, struct rtc_time *tm)
 174 {
 175         struct nuc900_rtc *rtc = dev_get_drvdata(dev);
 176         struct nuc900_bcd_time gettm;
 177         unsigned long val;
 178         int *err;
 179
 180         nuc900_rtc_bin2bcd(tm, &gettm);
 181
 182         err = check_rtc_access_enable(rtc);
 183         if (IS_ERR(err))
 184                 return PTR_ERR(err);
 185
 186         val = gettm.bcd_mday | gettm.bcd_mon | gettm.bcd_year;
 187         __raw_writel(val, rtc->rtc_reg + REG_RTC_CLR);
 188
 189         val = gettm.bcd_sec | gettm.bcd_min | gettm.bcd_hour;
 190         __raw_writel(val, rtc->rtc_reg + REG_RTC_TLR);
 191
 192         return 0;
 193 }
 194
 195 static int nuc900_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 196 {
 197         struct nuc900_rtc *rtc = dev_get_drvdata(dev);
 198         unsigned int timeval, carval;
 199
 200         timeval = __raw_readl(rtc->rtc_reg + REG_RTC_TAR);
 201         carval  = __raw_readl(rtc->rtc_reg + REG_RTC_CAR);
 202
 203         nuc900_rtc_bcd2bin(timeval, carval, &alrm->time);
 204
 205         return 0;
 206 }
 207
 208 static int nuc900_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 209 {
 210         struct nuc900_rtc *rtc = dev_get_drvdata(dev);
 211         struct nuc900_bcd_time tm;
 212         unsigned long val;
 213         int *err;
 214
 215         nuc900_rtc_bin2bcd(&alrm->time, &tm);
 216
 217         err = check_rtc_access_enable(rtc);
 218         if (IS_ERR(err))
 219                 return PTR_ERR(err);
 220
 221         val = tm.bcd_mday | tm.bcd_mon | tm.bcd_year;
 222         __raw_writel(val, rtc->rtc_reg + REG_RTC_CAR);
 223
 224         val = tm.bcd_sec | tm.bcd_min | tm.bcd_hour;
 225         __raw_writel(val, rtc->rtc_reg + REG_RTC_TAR);
 226
 227         return 0;
 228 }
 229
 230 static struct rtc_class_ops nuc900_rtc_ops = {
 231         .read_time = nuc900_rtc_read_time,
 232         .set_time = nuc900_rtc_set_time,
 233         .read_alarm = nuc900_rtc_read_alarm,
 234         .set_alarm = nuc900_rtc_set_alarm,
 235         .alarm_irq_enable = nuc900_alarm_irq_enable,
 236         .update_irq_enable = nuc900_update_irq_enable,
 237 };
 238
 239 static int __devinit nuc900_rtc_probe(struct platform_device *pdev)
 240 {
 241         struct resource *res;
 242         struct nuc900_rtc *nuc900_rtc;
 243         int err = 0;
 244
 245         nuc900_rtc = kzalloc(sizeof(struct nuc900_rtc), GFP_KERNEL);
 246         if (!nuc900_rtc) {
 247                 dev_err(&pdev->dev, "kzalloc nuc900_rtc failed\n");
 248                 return -ENOMEM;
 249         }
 250         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 251         if (!res) {
 252                 dev_err(&pdev->dev, "platform_get_resource failed\n");
 253                 err = -ENXIO;
 254                 goto fail1;
 255         }
 256
 257         if (!request_mem_region(res->start, resource_size(res),
 258                                 pdev->name)) {
 259                 dev_err(&pdev->dev, "request_mem_region failed\n");
 260                 err = -EBUSY;
 261                 goto fail1;
 262         }
 263
 264         nuc900_rtc->rtc_reg = ioremap(res->start, resource_size(res));
 265         if (!nuc900_rtc->rtc_reg) {
 266                 dev_err(&pdev->dev, "ioremap rtc_reg failed\n");
 267                 err = -ENOMEM;
 268                 goto fail2;
 269         }
 270
 271         nuc900_rtc->irq_num = platform_get_irq(pdev, 0);
 272         if (request_irq(nuc900_rtc->irq_num, nuc900_rtc_interrupt,
 273                                 IRQF_DISABLED, "nuc900rtc", nuc900_rtc)) {
 274                 dev_err(&pdev->dev, "NUC900 RTC request irq failed\n");
 275                 err = -EBUSY;
 276                 goto fail3;
 277         }
 278
 279         nuc900_rtc->rtcdev = rtc_device_register(pdev->name, &pdev->dev,
 280                                                 &nuc900_rtc_ops, THIS_MODULE);
 281         if (IS_ERR(nuc900_rtc->rtcdev)) {
 282                 dev_err(&pdev->dev, "rtc device register faild\n");
 283                 err = PTR_ERR(nuc900_rtc->rtcdev);
 284                 goto fail4;
 285         }
 286
 287         platform_set_drvdata(pdev, nuc900_rtc);
 288         __raw_writel(__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_TSSR) | MODE24,
 289                                         nuc900_rtc->rtc_reg + REG_RTC_TSSR);
 290
 291         return 0;
 292
 293 fail4:  free_irq(nuc900_rtc->irq_num, nuc900_rtc);
 294 fail3:  iounmap(nuc900_rtc->rtc_reg);
 295 fail2:  release_mem_region(res->start, resource_size(res));
 296 fail1:  kfree(nuc900_rtc);
 297         return err;
 298 }
 299
 300 static int __devexit nuc900_rtc_remove(struct platform_device *pdev)
 301 {
 302         struct nuc900_rtc *nuc900_rtc = platform_get_drvdata(pdev);
 303         struct resource *res;
 304
 305         rtc_device_unregister(nuc900_rtc->rtcdev);
 306         free_irq(nuc900_rtc->irq_num, nuc900_rtc);
 307         iounmap(nuc900_rtc->rtc_reg);
 308
 309         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 310         release_mem_region(res->start, resource_size(res));
 311
 312         kfree(nuc900_rtc);
 313
 314         platform_set_drvdata(pdev, NULL);
 315
 316         return 0;
 317 }
 318
 319 static struct platform_driver nuc900_rtc_driver = {
 320         .remove         = __devexit_p(nuc900_rtc_remove),
 321         .driver         = {
 322                 .name   = "nuc900-rtc",
 323                 .owner  = THIS_MODULE,
 324         },
 325 };
 326
 327 static int __init nuc900_rtc_init(void)
 328 {
 329         return platform_driver_probe(&nuc900_rtc_driver, nuc900_rtc_probe);
 330 }
 331
 332 static void __exit nuc900_rtc_exit(void)
 333 {
 334         platform_driver_unregister(&nuc900_rtc_driver);
 335 }
 336
 337 module_init(nuc900_rtc_init);
 338 module_exit(nuc900_rtc_exit);
 339
 340 MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
 341 MODULE_DESCRIPTION("nuc910/nuc920 RTC driver");
 342 MODULE_LICENSE("GPL");
 343 MODULE_ALIAS("platform:nuc900-rtc");