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/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/module.h> 18 #include <linux/rtc.h> /* For struct rtc_time and ioctls, etc */ 19 #include <linux/bcd.h> 20 #include <asm/bvme6000hw.h> 21 22 #include <asm/io.h> 23 #include <linux/uaccess.h> 24 #include <asm/setup.h> 25 26 /* 27 * We sponge a minor off of the misc major. No need slurping 28 * up another valuable major dev number for this. If you add 29 * an ioctl, make sure you don't conflict with SPARC's RTC 30 * ioctls. 31 */ 32 33 static unsigned char days_in_mo[] = 34 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; 35 36 static atomic_t rtc_status = ATOMIC_INIT(1); 37 38 static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 39 { 40 volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE; 41 unsigned char msr; 42 unsigned long flags; 43 struct rtc_time wtime; 44 void __user *argp = (void __user *)arg; 45 46 switch (cmd) { 47 case RTC_RD_TIME: /* Read the time/date from RTC */ 48 { 49 local_irq_save(flags); 50 /* Ensure clock and real-time-mode-register are accessible */ 51 msr = rtc->msr & 0xc0; 52 rtc->msr = 0x40; 53 memset(&wtime, 0, sizeof(struct rtc_time)); 54 do { 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 } while (wtime.tm_sec != bcd2bin(rtc->bcd_sec)); 65 rtc->msr = msr; 66 local_irq_restore(flags); 67 return copy_to_user(argp, &wtime, sizeof wtime) ? 68 -EFAULT : 0; 69 } 70 case RTC_SET_TIME: /* Set the RTC */ 71 { 72 struct rtc_time rtc_tm; 73 unsigned char mon, day, hrs, min, sec, leap_yr; 74 unsigned int yrs; 75 76 if (!capable(CAP_SYS_ADMIN)) 77 return -EACCES; 78 79 if (copy_from_user(&rtc_tm, argp, sizeof(struct rtc_time))) 80 return -EFAULT; 81 82 yrs = rtc_tm.tm_year; 83 if (yrs < 1900) 84 yrs += 1900; 85 mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */ 86 day = rtc_tm.tm_mday; 87 hrs = rtc_tm.tm_hour; 88 min = rtc_tm.tm_min; 89 sec = rtc_tm.tm_sec; 90 91 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400)); 92 93 if ((mon > 12) || (mon < 1) || (day == 0)) 94 return -EINVAL; 95 96 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr))) 97 return -EINVAL; 98 99 if ((hrs >= 24) || (min >= 60) || (sec >= 60)) 100 return -EINVAL; 101 102 if (yrs >= 2070) 103 return -EINVAL; 104 105 local_irq_save(flags); 106 /* Ensure clock and real-time-mode-register are accessible */ 107 msr = rtc->msr & 0xc0; 108 rtc->msr = 0x40; 109 110 rtc->t0cr_rtmr = yrs%4; 111 rtc->bcd_tenms = 0; 112 rtc->bcd_sec = bin2bcd(sec); 113 rtc->bcd_min = bin2bcd(min); 114 rtc->bcd_hr = bin2bcd(hrs); 115 rtc->bcd_dom = bin2bcd(day); 116 rtc->bcd_mth = bin2bcd(mon); 117 rtc->bcd_year = bin2bcd(yrs%100); 118 if (rtc_tm.tm_wday >= 0) 119 rtc->bcd_dow = bin2bcd(rtc_tm.tm_wday+1); 120 rtc->t0cr_rtmr = yrs%4 | 0x08; 121 122 rtc->msr = msr; 123 local_irq_restore(flags); 124 return 0; 125 } 126 default: 127 return -EINVAL; 128 } 129 } 130 131 /* 132 * We enforce only one user at a time here with the open/close. 133 */ 134 static int rtc_open(struct inode *inode, struct file *file) 135 { 136 if (!atomic_dec_and_test(&rtc_status)) { 137 atomic_inc(&rtc_status); 138 return -EBUSY; 139 } 140 return 0; 141 } 142 143 static int rtc_release(struct inode *inode, struct file *file) 144 { 145 atomic_inc(&rtc_status); 146 return 0; 147 } 148 149 /* 150 * The various file operations we support. 151 */ 152 153 static const struct file_operations rtc_fops = { 154 .unlocked_ioctl = rtc_ioctl, 155 .open = rtc_open, 156 .release = rtc_release, 157 .llseek = noop_llseek, 158 }; 159 160 static struct miscdevice rtc_dev = { 161 .minor = RTC_MINOR, 162 .name = "rtc", 163 .fops = &rtc_fops 164 }; 165 166 static int __init rtc_DP8570A_init(void) 167 { 168 if (!MACH_IS_BVME6000) 169 return -ENODEV; 170 171 pr_info("DP8570A Real Time Clock Driver v%s\n", RTC_VERSION); 172 return misc_register(&rtc_dev); 173 } 174 module_init(rtc_DP8570A_init); 175