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/ioport.h> 14 #include <linux/fcntl.h> 15 #include <linux/init.h> 16 #include <linux/poll.h> 17 #include <linux/module.h> 18 #include <linux/mc146818rtc.h> /* For struct rtc_time and ioctls, etc */ 19 #include <linux/smp_lock.h> 20 #include <asm/bvme6000hw.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 #define BCD2BIN(val) (((val)&15) + ((val)>>4)*10) 35 #define BIN2BCD(val) ((((val)/10)<<4) + (val)%10) 36 37 static unsigned char days_in_mo[] = 38 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; 39 40 static char rtc_status; 41 42 static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd, 43 unsigned long arg) 44 { 45 volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE; 46 unsigned char msr; 47 unsigned long flags; 48 struct rtc_time wtime; 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((void *)arg, &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, (struct rtc_time*)arg, 84 sizeof(struct rtc_time))) 85 return -EFAULT; 86 87 yrs = rtc_tm.tm_year; 88 if (yrs < 1900) 89 yrs += 1900; 90 mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */ 91 day = rtc_tm.tm_mday; 92 hrs = rtc_tm.tm_hour; 93 min = rtc_tm.tm_min; 94 sec = rtc_tm.tm_sec; 95 96 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400)); 97 98 if ((mon > 12) || (mon < 1) || (day == 0)) 99 return -EINVAL; 100 101 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr))) 102 return -EINVAL; 103 104 if ((hrs >= 24) || (min >= 60) || (sec >= 60)) 105 return -EINVAL; 106 107 if (yrs >= 2070) 108 return -EINVAL; 109 110 local_irq_save(flags); 111 /* Ensure clock and real-time-mode-register are accessible */ 112 msr = rtc->msr & 0xc0; 113 rtc->msr = 0x40; 114 115 rtc->t0cr_rtmr = yrs%4; 116 rtc->bcd_tenms = 0; 117 rtc->bcd_sec = BIN2BCD(sec); 118 rtc->bcd_min = BIN2BCD(min); 119 rtc->bcd_hr = BIN2BCD(hrs); 120 rtc->bcd_dom = BIN2BCD(day); 121 rtc->bcd_mth = BIN2BCD(mon); 122 rtc->bcd_year = BIN2BCD(yrs%100); 123 if (rtc_tm.tm_wday >= 0) 124 rtc->bcd_dow = BIN2BCD(rtc_tm.tm_wday+1); 125 rtc->t0cr_rtmr = yrs%4 | 0x08; 126 127 rtc->msr = msr; 128 local_irq_restore(flags); 129 return 0; 130 } 131 default: 132 return -EINVAL; 133 } 134 } 135 136 /* 137 * We enforce only one user at a time here with the open/close. 138 * Also clear the previous interrupt data on an open, and clean 139 * up things on a close. 140 */ 141 142 static int rtc_open(struct inode *inode, struct file *file) 143 { 144 if(rtc_status) 145 return -EBUSY; 146 147 rtc_status = 1; 148 return 0; 149 } 150 151 static int rtc_release(struct inode *inode, struct file *file) 152 { 153 lock_kernel(); 154 rtc_status = 0; 155 unlock_kernel(); 156 return 0; 157 } 158 159 /* 160 * The various file operations we support. 161 */ 162 163 static struct file_operations rtc_fops = { 164 .ioctl = rtc_ioctl, 165 .open = rtc_open, 166 .release = rtc_release, 167 }; 168 169 static struct miscdevice rtc_dev = { 170 .minor = RTC_MINOR, 171 .name = "rtc", 172 .fops = &rtc_fops 173 }; 174 175 static int __init rtc_DP8570A_init(void) 176 { 177 if (!MACH_IS_BVME6000) 178 return -ENODEV; 179 180 printk(KERN_INFO "DP8570A Real Time Clock Driver v%s\n", RTC_VERSION); 181 return misc_register(&rtc_dev); 182 } 183 module_init(rtc_DP8570A_init); 184