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