drivers/sbus/char/rtc.c

   1 /* $Id: rtc.c,v 1.28 2001/10/08 22:19:51 davem Exp $
   2  *
   3  * Linux/SPARC Real Time Clock Driver
   4  * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu)
   5  *
   6  * This is a little driver that lets a user-level program access
   7  * the SPARC Mostek real time clock chip. It is no use unless you
   8  * use the modified clock utility.
   9  *
  10  * Get the modified clock utility from:
  11  *   ftp://vger.kernel.org/pub/linux/Sparc/userland/clock.c
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/types.h>
  16 #include <linux/errno.h>
  17 #include <linux/miscdevice.h>
  18 #include <linux/slab.h>
  19 #include <linux/fcntl.h>
  20 #include <linux/poll.h>
  21 #include <linux/init.h>
  22 #include <asm/io.h>
  23 #include <asm/mostek.h>
  24 #include <asm/system.h>
  25 #include <asm/uaccess.h>
  26 #include <asm/rtc.h>
  27
  28 static int rtc_busy = 0;
  29
  30 /* This is the structure layout used by drivers/char/rtc.c, we
  31  * support that driver's ioctls so that things are less messy in
  32  * userspace.
  33  */
  34 struct rtc_time_generic {
  35         int tm_sec;
  36         int tm_min;
  37         int tm_hour;
  38         int tm_mday;
  39         int tm_mon;
  40         int tm_year;
  41         int tm_wday;
  42         int tm_yday;
  43         int tm_isdst;
  44 };
  45 #define RTC_AIE_ON      _IO('p', 0x01)  /* Alarm int. enable on         */
  46 #define RTC_AIE_OFF     _IO('p', 0x02)  /* ... off                      */
  47 #define RTC_UIE_ON      _IO('p', 0x03)  /* Update int. enable on        */
  48 #define RTC_UIE_OFF     _IO('p', 0x04)  /* ... off                      */
  49 #define RTC_PIE_ON      _IO('p', 0x05)  /* Periodic int. enable on      */
  50 #define RTC_PIE_OFF     _IO('p', 0x06)  /* ... off                      */
  51 #define RTC_WIE_ON      _IO('p', 0x0f)  /* Watchdog int. enable on      */
  52 #define RTC_WIE_OFF     _IO('p', 0x10)  /* ... off                      */
  53 #define RTC_RD_TIME     _IOR('p', 0x09, struct rtc_time_generic) /* Read RTC time   */
  54 #define RTC_SET_TIME    _IOW('p', 0x0a, struct rtc_time_generic) /* Set RTC time    */
  55 #define RTC_ALM_SET     _IOW('p', 0x07, struct rtc_time) /* Set alarm time  */
  56 #define RTC_ALM_READ    _IOR('p', 0x08, struct rtc_time) /* Read alarm time */
  57 #define RTC_IRQP_READ   _IOR('p', 0x0b, unsigned long)   /* Read IRQ rate   */
  58 #define RTC_IRQP_SET    _IOW('p', 0x0c, unsigned long)   /* Set IRQ rate    */
  59 #define RTC_EPOCH_READ  _IOR('p', 0x0d, unsigned long)   /* Read epoch      */
  60 #define RTC_EPOCH_SET   _IOW('p', 0x0e, unsigned long)   /* Set epoch       */
  61 #define RTC_WKALM_SET   _IOW('p', 0x0f, struct rtc_wkalrm)/* Set wakeup alarm*/
  62 #define RTC_WKALM_RD    _IOR('p', 0x10, struct rtc_wkalrm)/* Get wakeup alarm*/
  63 #define RTC_PLL_GET     _IOR('p', 0x11, struct rtc_pll_info)  /* Get PLL correction */
  64 #define RTC_PLL_SET     _IOW('p', 0x12, struct rtc_pll_info)  /* Set PLL correction */
  65
  66 /* Retrieve the current date and time from the real time clock. */
  67 static void get_rtc_time(struct rtc_time *t)
  68 {
  69         void __iomem *regs = mstk48t02_regs;
  70         u8 tmp;
  71
  72         spin_lock_irq(&mostek_lock);
  73
  74         tmp = mostek_read(regs + MOSTEK_CREG);
  75         tmp |= MSTK_CREG_READ;
  76         mostek_write(regs + MOSTEK_CREG, tmp);
  77
  78         t->sec = MSTK_REG_SEC(regs);
  79         t->min = MSTK_REG_MIN(regs);
  80         t->hour = MSTK_REG_HOUR(regs);
  81         t->dow = MSTK_REG_DOW(regs);
  82         t->dom = MSTK_REG_DOM(regs);
  83         t->month = MSTK_REG_MONTH(regs);
  84         t->year = MSTK_CVT_YEAR( MSTK_REG_YEAR(regs) );
  85
  86         tmp = mostek_read(regs + MOSTEK_CREG);
  87         tmp &= ~MSTK_CREG_READ;
  88         mostek_write(regs + MOSTEK_CREG, tmp);
  89
  90         spin_unlock_irq(&mostek_lock);
  91 }
  92
  93 /* Set the current date and time inthe real time clock. */
  94 void set_rtc_time(struct rtc_time *t)
  95 {
  96         void __iomem *regs = mstk48t02_regs;
  97         u8 tmp;
  98
  99         spin_lock_irq(&mostek_lock);
 100
 101         tmp = mostek_read(regs + MOSTEK_CREG);
 102         tmp |= MSTK_CREG_WRITE;
 103         mostek_write(regs + MOSTEK_CREG, tmp);
 104
 105         MSTK_SET_REG_SEC(regs,t->sec);
 106         MSTK_SET_REG_MIN(regs,t->min);
 107         MSTK_SET_REG_HOUR(regs,t->hour);
 108         MSTK_SET_REG_DOW(regs,t->dow);
 109         MSTK_SET_REG_DOM(regs,t->dom);
 110         MSTK_SET_REG_MONTH(regs,t->month);
 111         MSTK_SET_REG_YEAR(regs,t->year - MSTK_YEAR_ZERO);
 112
 113         tmp = mostek_read(regs + MOSTEK_CREG);
 114         tmp &= ~MSTK_CREG_WRITE;
 115         mostek_write(regs + MOSTEK_CREG, tmp);
 116
 117         spin_unlock_irq(&mostek_lock);
 118 }
 119
 120 static int put_rtc_time_generic(void __user *argp, struct rtc_time *tm)
 121 {
 122         struct rtc_time_generic __user *utm = argp;
 123
 124         if (__put_user(tm->sec, &utm->tm_sec) ||
 125             __put_user(tm->min, &utm->tm_min) ||
 126             __put_user(tm->hour, &utm->tm_hour) ||
 127             __put_user(tm->dom, &utm->tm_mday) ||
 128             __put_user(tm->month, &utm->tm_mon) ||
 129             __put_user(tm->year, &utm->tm_year) ||
 130             __put_user(tm->dow, &utm->tm_wday) ||
 131             __put_user(0, &utm->tm_yday) ||
 132             __put_user(0, &utm->tm_isdst))
 133                 return -EFAULT;
 134
 135         return 0;
 136 }
 137
 138 static int get_rtc_time_generic(struct rtc_time *tm, void __user *argp)
 139 {
 140         struct rtc_time_generic __user *utm = argp;
 141
 142         if (__get_user(tm->sec, &utm->tm_sec) ||
 143             __get_user(tm->min, &utm->tm_min) ||
 144             __get_user(tm->hour, &utm->tm_hour) ||
 145             __get_user(tm->dom, &utm->tm_mday) ||
 146             __get_user(tm->month, &utm->tm_mon) ||
 147             __get_user(tm->year, &utm->tm_year) ||
 148             __get_user(tm->dow, &utm->tm_wday))
 149                 return -EFAULT;
 150
 151         return 0;
 152 }
 153
 154 static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 155         unsigned long arg)
 156 {
 157         struct rtc_time rtc_tm;
 158         void __user *argp = (void __user *)arg;
 159
 160         switch (cmd) {
 161         /* No interrupt support, return an error
 162          * compatible with drivers/char/rtc.c
 163          */
 164         case RTC_AIE_OFF:
 165         case RTC_AIE_ON:
 166         case RTC_PIE_OFF:
 167         case RTC_PIE_ON:
 168         case RTC_UIE_OFF:
 169         case RTC_UIE_ON:
 170         case RTC_IRQP_READ:
 171         case RTC_IRQP_SET:
 172         case RTC_EPOCH_SET:
 173         case RTC_EPOCH_READ:
 174                 return -EINVAL;
 175
 176         case RTCGET:
 177         case RTC_RD_TIME:
 178                 memset(&rtc_tm, 0, sizeof(struct rtc_time));
 179                 get_rtc_time(&rtc_tm);
 180
 181                 if (cmd == RTCGET) {
 182                         if (copy_to_user(argp, &rtc_tm,
 183                                          sizeof(struct rtc_time)))
 184                                 return -EFAULT;
 185                 } else if (put_rtc_time_generic(argp, &rtc_tm))
 186                         return -EFAULT;
 187
 188                 return 0;
 189
 190
 191         case RTCSET:
 192         case RTC_SET_TIME:
 193                 if (!capable(CAP_SYS_TIME))
 194                         return -EPERM;
 195
 196                 if (cmd == RTCSET) {
 197                         if (copy_from_user(&rtc_tm, argp,
 198                                            sizeof(struct rtc_time)))
 199                                 return -EFAULT;
 200                 } else if (get_rtc_time_generic(&rtc_tm, argp))
 201                         return -EFAULT;
 202
 203                 set_rtc_time(&rtc_tm);
 204
 205                 return 0;
 206
 207         default:
 208                 return -EINVAL;
 209         }
 210 }
 211
 212 static int rtc_open(struct inode *inode, struct file *file)
 213 {
 214         int ret;
 215
 216         spin_lock_irq(&mostek_lock);
 217         if (rtc_busy) {
 218                 ret = -EBUSY;
 219         } else {
 220                 rtc_busy = 1;
 221                 ret = 0;
 222         }
 223         spin_unlock_irq(&mostek_lock);
 224
 225         return ret;
 226 }
 227
 228 static int rtc_release(struct inode *inode, struct file *file)
 229 {
 230         rtc_busy = 0;
 231
 232         return 0;
 233 }
 234
 235 static const struct file_operations rtc_fops = {
 236         .owner =        THIS_MODULE,
 237         .llseek =       no_llseek,
 238         .ioctl =        rtc_ioctl,
 239         .open =         rtc_open,
 240         .release =      rtc_release,
 241 };
 242
 243 static struct miscdevice rtc_dev = { RTC_MINOR, "rtc", &rtc_fops };
 244
 245 static int __init rtc_sun_init(void)
 246 {
 247         int error;
 248
 249         /* It is possible we are being driven by some other RTC chip
 250          * and thus another RTC driver is handling things.
 251          */
 252         if (!mstk48t02_regs)
 253                 return -ENODEV;
 254
 255         error = misc_register(&rtc_dev);
 256         if (error) {
 257                 printk(KERN_ERR "rtc: unable to get misc minor for Mostek\n");
 258                 return error;
 259         }
 260         printk("rtc_sun_init: Registered Mostek RTC driver.\n");
 261
 262         return 0;
 263 }
 264
 265 static void __exit rtc_sun_cleanup(void)
 266 {
 267         misc_deregister(&rtc_dev);
 268 }
 269
 270 module_init(rtc_sun_init);
 271 module_exit(rtc_sun_cleanup);
 272 MODULE_LICENSE("GPL");