1 /* 2 * Real Time Clock interface for Linux on the MVME16x 3 * 4 * Based on the PC driver by Paul Gortmaker. 5 */ 6 7 #define RTC_VERSION "1.00" 8 9 #include <linux/types.h> 10 #include <linux/errno.h> 11 #include <linux/miscdevice.h> 12 #include <linux/slab.h> 13 #include <linux/smp_lock.h> 14 #include <linux/ioport.h> 15 #include <linux/capability.h> 16 #include <linux/fcntl.h> 17 #include <linux/init.h> 18 #include <linux/poll.h> 19 #include <linux/mc146818rtc.h> /* For struct rtc_time and ioctls, etc */ 20 #include <linux/bcd.h> 21 #include <asm/mvme16xhw.h> 22 23 #include <asm/io.h> 24 #include <asm/uaccess.h> 25 #include <asm/system.h> 26 #include <asm/setup.h> 27 28 /* 29 * We sponge a minor off of the misc major. No need slurping 30 * up another valuable major dev number for this. If you add 31 * an ioctl, make sure you don't conflict with SPARC's RTC 32 * ioctls. 33 */ 34 35 static const unsigned char days_in_mo[] = 36 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; 37 38 static atomic_t rtc_ready = ATOMIC_INIT(1); 39 40 static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd, 41 unsigned long arg) 42 { 43 volatile MK48T08ptr_t rtc = (MK48T08ptr_t)MVME_RTC_BASE; 44 unsigned long flags; 45 struct rtc_time wtime; 46 void __user *argp = (void __user *)arg; 47 48 switch (cmd) { 49 case RTC_RD_TIME: /* Read the time/date from RTC */ 50 { 51 local_irq_save(flags); 52 /* Ensure clock and real-time-mode-register are accessible */ 53 rtc->ctrl = RTC_READ; 54 memset(&wtime, 0, sizeof(struct rtc_time)); 55 wtime.tm_sec = bcd2bin(rtc->bcd_sec); 56 wtime.tm_min = bcd2bin(rtc->bcd_min); 57 wtime.tm_hour = bcd2bin(rtc->bcd_hr); 58 wtime.tm_mday = bcd2bin(rtc->bcd_dom); 59 wtime.tm_mon = bcd2bin(rtc->bcd_mth)-1; 60 wtime.tm_year = bcd2bin(rtc->bcd_year); 61 if (wtime.tm_year < 70) 62 wtime.tm_year += 100; 63 wtime.tm_wday = bcd2bin(rtc->bcd_dow)-1; 64 rtc->ctrl = 0; 65 local_irq_restore(flags); 66 return copy_to_user(argp, &wtime, sizeof wtime) ? 67 -EFAULT : 0; 68 } 69 case RTC_SET_TIME: /* Set the RTC */ 70 { 71 struct rtc_time rtc_tm; 72 unsigned char mon, day, hrs, min, sec, leap_yr; 73 unsigned int yrs; 74 75 if (!capable(CAP_SYS_ADMIN)) 76 return -EACCES; 77 78 if (copy_from_user(&rtc_tm, argp, sizeof(struct rtc_time))) 79 return -EFAULT; 80 81 yrs = rtc_tm.tm_year; 82 if (yrs < 1900) 83 yrs += 1900; 84 mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */ 85 day = rtc_tm.tm_mday; 86 hrs = rtc_tm.tm_hour; 87 min = rtc_tm.tm_min; 88 sec = rtc_tm.tm_sec; 89 90 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400)); 91 92 if ((mon > 12) || (day == 0)) 93 return -EINVAL; 94 95 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr))) 96 return -EINVAL; 97 98 if ((hrs >= 24) || (min >= 60) || (sec >= 60)) 99 return -EINVAL; 100 101 if (yrs >= 2070) 102 return -EINVAL; 103 104 local_irq_save(flags); 105 rtc->ctrl = RTC_WRITE; 106 107 rtc->bcd_sec = bin2bcd(sec); 108 rtc->bcd_min = bin2bcd(min); 109 rtc->bcd_hr = bin2bcd(hrs); 110 rtc->bcd_dom = bin2bcd(day); 111 rtc->bcd_mth = bin2bcd(mon); 112 rtc->bcd_year = bin2bcd(yrs%100); 113 114 rtc->ctrl = 0; 115 local_irq_restore(flags); 116 return 0; 117 } 118 default: 119 return -EINVAL; 120 } 121 } 122 123 /* 124 * We enforce only one user at a time here with the open/close. 125 * Also clear the previous interrupt data on an open, and clean 126 * up things on a close. 127 */ 128 129 static int rtc_open(struct inode *inode, struct file *file) 130 { 131 lock_kernel(); 132 if( !atomic_dec_and_test(&rtc_ready) ) 133 { 134 atomic_inc( &rtc_ready ); 135 unlock_kernel(); 136 return -EBUSY; 137 } 138 unlock_kernel(); 139 140 return 0; 141 } 142 143 static int rtc_release(struct inode *inode, struct file *file) 144 { 145 atomic_inc( &rtc_ready ); 146 return 0; 147 } 148 149 /* 150 * The various file operations we support. 151 */ 152 153 static const struct file_operations rtc_fops = { 154 .ioctl = rtc_ioctl, 155 .open = rtc_open, 156 .release = rtc_release, 157 }; 158 159 static struct miscdevice rtc_dev= 160 { 161 .minor = RTC_MINOR, 162 .name = "rtc", 163 .fops = &rtc_fops 164 }; 165 166 static int __init rtc_MK48T08_init(void) 167 { 168 if (!MACH_IS_MVME16x) 169 return -ENODEV; 170 171 printk(KERN_INFO "MK48T08 Real Time Clock Driver v%s\n", RTC_VERSION); 172 return misc_register(&rtc_dev); 173 } 174 module_init(rtc_MK48T08_init); 175