1 /* 2 * Real Time Clock interface for Linux on the BVME6000 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/module.h> 20 #include <linux/mc146818rtc.h> /* For struct rtc_time and ioctls, etc */ 21 #include <linux/bcd.h> 22 #include <asm/bvme6000hw.h> 23 24 #include <asm/io.h> 25 #include <asm/uaccess.h> 26 #include <asm/system.h> 27 #include <asm/setup.h> 28 29 /* 30 * We sponge a minor off of the misc major. No need slurping 31 * up another valuable major dev number for this. If you add 32 * an ioctl, make sure you don't conflict with SPARC's RTC 33 * ioctls. 34 */ 35 36 static unsigned char days_in_mo[] = 37 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; 38 39 static char rtc_status; 40 41 static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd, 42 unsigned long arg) 43 { 44 volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE; 45 unsigned char msr; 46 unsigned long flags; 47 struct rtc_time wtime; 48 void __user *argp = (void __user *)arg; 49 50 switch (cmd) { 51 case RTC_RD_TIME: /* Read the time/date from RTC */ 52 { 53 local_irq_save(flags); 54 /* Ensure clock and real-time-mode-register are accessible */ 55 msr = rtc->msr & 0xc0; 56 rtc->msr = 0x40; 57 memset(&wtime, 0, sizeof(struct rtc_time)); 58 do { 59 wtime.tm_sec = bcd2bin(rtc->bcd_sec); 60 wtime.tm_min = bcd2bin(rtc->bcd_min); 61 wtime.tm_hour = bcd2bin(rtc->bcd_hr); 62 wtime.tm_mday = bcd2bin(rtc->bcd_dom); 63 wtime.tm_mon = bcd2bin(rtc->bcd_mth)-1; 64 wtime.tm_year = bcd2bin(rtc->bcd_year); 65 if (wtime.tm_year < 70) 66 wtime.tm_year += 100; 67 wtime.tm_wday = bcd2bin(rtc->bcd_dow)-1; 68 } while (wtime.tm_sec != bcd2bin(rtc->bcd_sec)); 69 rtc->msr = msr; 70 local_irq_restore(flags); 71 return copy_to_user(argp, &wtime, sizeof wtime) ? 72 -EFAULT : 0; 73 } 74 case RTC_SET_TIME: /* Set the RTC */ 75 { 76 struct rtc_time rtc_tm; 77 unsigned char mon, day, hrs, min, sec, leap_yr; 78 unsigned int yrs; 79 80 if (!capable(CAP_SYS_ADMIN)) 81 return -EACCES; 82 83 if (copy_from_user(&rtc_tm, argp, sizeof(struct rtc_time))) 84 return -EFAULT; 85 86 yrs = rtc_tm.tm_year; 87 if (yrs < 1900) 88 yrs += 1900; 89 mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */ 90 day = rtc_tm.tm_mday; 91 hrs = rtc_tm.tm_hour; 92 min = rtc_tm.tm_min; 93 sec = rtc_tm.tm_sec; 94 95 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400)); 96 97 if ((mon > 12) || (mon < 1) || (day == 0)) 98 return -EINVAL; 99 100 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr))) 101 return -EINVAL; 102 103 if ((hrs >= 24) || (min >= 60) || (sec >= 60)) 104 return -EINVAL; 105 106 if (yrs >= 2070) 107 return -EINVAL; 108 109 local_irq_save(flags); 110 /* Ensure clock and real-time-mode-register are accessible */ 111 msr = rtc->msr & 0xc0; 112 rtc->msr = 0x40; 113 114 rtc->t0cr_rtmr = yrs%4; 115 rtc->bcd_tenms = 0; 116 rtc->bcd_sec = bin2bcd(sec); 117 rtc->bcd_min = bin2bcd(min); 118 rtc->bcd_hr = bin2bcd(hrs); 119 rtc->bcd_dom = bin2bcd(day); 120 rtc->bcd_mth = bin2bcd(mon); 121 rtc->bcd_year = bin2bcd(yrs%100); 122 if (rtc_tm.tm_wday >= 0) 123 rtc->bcd_dow = bin2bcd(rtc_tm.tm_wday+1); 124 rtc->t0cr_rtmr = yrs%4 | 0x08; 125 126 rtc->msr = msr; 127 local_irq_restore(flags); 128 return 0; 129 } 130 default: 131 return -EINVAL; 132 } 133 } 134 135 /* 136 * We enforce only one user at a time here with the open/close. 137 * Also clear the previous interrupt data on an open, and clean 138 * up things on a close. 139 */ 140 141 static int rtc_open(struct inode *inode, struct file *file) 142 { 143 lock_kernel(); 144 if(rtc_status) { 145 unlock_kernel(); 146 return -EBUSY; 147 } 148 149 rtc_status = 1; 150 unlock_kernel(); 151 return 0; 152 } 153 154 static int rtc_release(struct inode *inode, struct file *file) 155 { 156 lock_kernel(); 157 rtc_status = 0; 158 unlock_kernel(); 159 return 0; 160 } 161 162 /* 163 * The various file operations we support. 164 */ 165 166 static const struct file_operations rtc_fops = { 167 .ioctl = rtc_ioctl, 168 .open = rtc_open, 169 .release = rtc_release, 170 }; 171 172 static struct miscdevice rtc_dev = { 173 .minor = RTC_MINOR, 174 .name = "rtc", 175 .fops = &rtc_fops 176 }; 177 178 static int __init rtc_DP8570A_init(void) 179 { 180 if (!MACH_IS_BVME6000) 181 return -ENODEV; 182 183 printk(KERN_INFO "DP8570A Real Time Clock Driver v%s\n", RTC_VERSION); 184 return misc_register(&rtc_dev); 185 } 186 module_init(rtc_DP8570A_init); 187