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/ioport.h> 14 #include <linux/capability.h> 15 #include <linux/fcntl.h> 16 #include <linux/init.h> 17 #include <linux/poll.h> 18 #include <linux/mc146818rtc.h> /* For struct rtc_time and ioctls, etc */ 19 #include <linux/bcd.h> 20 #include <asm/mvme16xhw.h> 21 22 #include <asm/io.h> 23 #include <asm/uaccess.h> 24 #include <asm/system.h> 25 #include <asm/setup.h> 26 27 /* 28 * We sponge a minor off of the misc major. No need slurping 29 * up another valuable major dev number for this. If you add 30 * an ioctl, make sure you don't conflict with SPARC's RTC 31 * ioctls. 32 */ 33 34 static const unsigned char days_in_mo[] = 35 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; 36 37 static atomic_t rtc_ready = ATOMIC_INIT(1); 38 39 static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd, 40 unsigned long arg) 41 { 42 volatile MK48T08ptr_t rtc = (MK48T08ptr_t)MVME_RTC_BASE; 43 unsigned long flags; 44 struct rtc_time wtime; 45 void __user *argp = (void __user *)arg; 46 47 switch (cmd) { 48 case RTC_RD_TIME: /* Read the time/date from RTC */ 49 { 50 local_irq_save(flags); 51 /* Ensure clock and real-time-mode-register are accessible */ 52 rtc->ctrl = RTC_READ; 53 memset(&wtime, 0, sizeof(struct rtc_time)); 54 wtime.tm_sec = BCD2BIN(rtc->bcd_sec); 55 wtime.tm_min = BCD2BIN(rtc->bcd_min); 56 wtime.tm_hour = BCD2BIN(rtc->bcd_hr); 57 wtime.tm_mday = BCD2BIN(rtc->bcd_dom); 58 wtime.tm_mon = BCD2BIN(rtc->bcd_mth)-1; 59 wtime.tm_year = BCD2BIN(rtc->bcd_year); 60 if (wtime.tm_year < 70) 61 wtime.tm_year += 100; 62 wtime.tm_wday = BCD2BIN(rtc->bcd_dow)-1; 63 rtc->ctrl = 0; 64 local_irq_restore(flags); 65 return copy_to_user(argp, &wtime, sizeof wtime) ? 66 -EFAULT : 0; 67 } 68 case RTC_SET_TIME: /* Set the RTC */ 69 { 70 struct rtc_time rtc_tm; 71 unsigned char mon, day, hrs, min, sec, leap_yr; 72 unsigned int yrs; 73 74 if (!capable(CAP_SYS_ADMIN)) 75 return -EACCES; 76 77 if (copy_from_user(&rtc_tm, argp, sizeof(struct rtc_time))) 78 return -EFAULT; 79 80 yrs = rtc_tm.tm_year; 81 if (yrs < 1900) 82 yrs += 1900; 83 mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */ 84 day = rtc_tm.tm_mday; 85 hrs = rtc_tm.tm_hour; 86 min = rtc_tm.tm_min; 87 sec = rtc_tm.tm_sec; 88 89 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400)); 90 91 if ((mon > 12) || (day == 0)) 92 return -EINVAL; 93 94 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr))) 95 return -EINVAL; 96 97 if ((hrs >= 24) || (min >= 60) || (sec >= 60)) 98 return -EINVAL; 99 100 if (yrs >= 2070) 101 return -EINVAL; 102 103 local_irq_save(flags); 104 rtc->ctrl = RTC_WRITE; 105 106 rtc->bcd_sec = BIN2BCD(sec); 107 rtc->bcd_min = BIN2BCD(min); 108 rtc->bcd_hr = BIN2BCD(hrs); 109 rtc->bcd_dom = BIN2BCD(day); 110 rtc->bcd_mth = BIN2BCD(mon); 111 rtc->bcd_year = BIN2BCD(yrs%100); 112 113 rtc->ctrl = 0; 114 local_irq_restore(flags); 115 return 0; 116 } 117 default: 118 return -EINVAL; 119 } 120 } 121 122 /* 123 * We enforce only one user at a time here with the open/close. 124 * Also clear the previous interrupt data on an open, and clean 125 * up things on a close. 126 */ 127 128 static int rtc_open(struct inode *inode, struct file *file) 129 { 130 if( !atomic_dec_and_test(&rtc_ready) ) 131 { 132 atomic_inc( &rtc_ready ); 133 return -EBUSY; 134 } 135 136 return 0; 137 } 138 139 static int rtc_release(struct inode *inode, struct file *file) 140 { 141 atomic_inc( &rtc_ready ); 142 return 0; 143 } 144 145 /* 146 * The various file operations we support. 147 */ 148 149 static const struct file_operations rtc_fops = { 150 .ioctl = rtc_ioctl, 151 .open = rtc_open, 152 .release = rtc_release, 153 }; 154 155 static struct miscdevice rtc_dev= 156 { 157 .minor = RTC_MINOR, 158 .name = "rtc", 159 .fops = &rtc_fops 160 }; 161 162 static int __init rtc_MK48T08_init(void) 163 { 164 if (!MACH_IS_MVME16x) 165 return -ENODEV; 166 167 printk(KERN_INFO "MK48T08 Real Time Clock Driver v%s\n", RTC_VERSION); 168 return misc_register(&rtc_dev); 169 } 170 module_init(rtc_MK48T08_init); 171