patch-2.3.43 linux/drivers/char/efirtc.c

• Lines: 357
• Date: Thu Feb 10 12:38:03 2000
• Orig file: v2.3.42/linux/drivers/char/efirtc.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.42/linux/drivers/char/efirtc.c linux/drivers/char/efirtc.c
@@ -0,0 +1,356 @@
+/*
+ * EFI Time Services Driver for Linux
+ *
+ * Copyright (C) 1999 Hewlett-Packard Co
+ * Copyright (C) 1999 Stephane Eranian <eranian@hpl.hp.com>
+ *
+ * Based on skeleton from the drivers/char/rtc.c driver by P. Gortmaker
+ *
+ * This code provides a architected & portable interface to the real time 
+ * clock by using EFI instead of direct bit fiddling. The functionalities are 
+ * quite different from the rtc.c driver. The only way to talk to the device 
+ * is by using ioctl(). There is a /proc interface which provides the raw 
+ * information.
+ *
+ * Please note that we have kept the API as close as possible from the 
+ * legacy RTC. The standard /sbin/hwclock program should work normally 
+ * when used to get/set the time.
+ *
+ * NOTES:
+ *	- Locking is required for safe execution of EFI calls with regards
+ *	  to interrrupts and SMP.
+ *
+ * TODO (December 1999):
+ * 	- provide the API to set/get the WakeUp Alarm (different from the
+ *	  rtc.c alarm).
+ *	- SMP testing
+ * 	- Add module support
+ */
+
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/miscdevice.h>
+#include <linux/init.h>
+#include <linux/rtc.h>
+#include <linux/proc_fs.h>
+
+#include <asm/efi.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+#define EFI_RTC_VERSION		"0.1"
+
+#define EFI_ISDST (EFI_TIME_ADJUST_DAYLIGHT|EFI_TIME_IN_DAYLIGHT)
+/*
+ * EFI Epoch is 1/1/1998
+ */
+#define EFI_RTC_EPOCH		1998
+
+static spinlock_t efi_rtc_lock;
+
+static int efi_rtc_ioctl(struct inode *inode, struct file *file,
+		     unsigned int cmd, unsigned long arg);
+
+#define is_leap(year) \
+          ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
+
+static const unsigned short int __mon_yday[2][13] =
+{
+	/* Normal years.  */
+	{ 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
+	/* Leap years.  */  
+	{ 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
+};
+
+/*
+ * returns day of the year [0-365]
+ */
+static inline int
+compute_yday(efi_time_t *eft)
+{
+	/* efi_time_t.month is in the [1-12] so, we need -1 */
+	return  __mon_yday[is_leap(eft->year)][eft->month-1]+ eft->day -1;
+}
+/*
+ * returns day of the week [0-6] 0=Sunday
+ *
+ * Don't try to provide a year that's before 1998, please !
+ */
+static int
+compute_wday(efi_time_t *eft)
+{
+	int y;
+	int ndays = 0;
+
+	if ( eft->year < 1998 ) {
+		printk(KERN_ERR "efirtc: EFI year < 1998, invalid date\n");
+		return -1;
+	}
+
+	for(y=EFI_RTC_EPOCH; y < eft->year; y++ ) {
+		ndays += 365 + (is_leap(y) ? 1 : 0);
+	}
+	ndays += compute_yday(eft);
+
+	/*
+	 * 4=1/1/1998 was a Thursday
+	 */
+	return (ndays + 4) % 7;
+}
+
+static void
+convert_to_efi_time(struct rtc_time *wtime, efi_time_t *eft)
+{
+
+	eft->year	= wtime->tm_year + 1900;
+	eft->month	= wtime->tm_mon + 1; 
+	eft->day	= wtime->tm_mday;
+	eft->hour	= wtime->tm_hour;
+	eft->minute	= wtime->tm_min;
+	eft->second 	= wtime->tm_sec;
+	eft->nanosecond = 0; 
+	eft->daylight	= wtime->tm_isdst ? EFI_ISDST: 0;
+	eft->timezone	= EFI_UNSPECIFIED_TIMEZONE;
+}
+
+static void
+convert_from_efi_time(efi_time_t *eft, struct rtc_time *wtime)
+{
+	wtime->tm_sec  = eft->second;
+	wtime->tm_min  = eft->minute;
+	wtime->tm_hour = eft->hour;
+	wtime->tm_mday = eft->day;
+	wtime->tm_mon  = eft->month - 1;
+	wtime->tm_year = eft->year - 1900;
+
+	/* day of the week [0-6], Sunday=0 */
+	wtime->tm_wday = compute_wday(eft);
+
+	/* day in the year [1-365]*/
+	wtime->tm_yday = compute_yday(eft);
+
+
+	switch (eft->daylight & EFI_ISDST) {
+		case EFI_ISDST:
+			wtime->tm_isdst = 1;
+			break;
+		case EFI_TIME_ADJUST_DAYLIGHT:
+			wtime->tm_isdst = 0;
+			break;
+		default:
+			wtime->tm_isdst = -1;
+	}
+}
+
+static int
+efi_rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+		     unsigned long arg)
+{
+
+	efi_status_t	status;
+	unsigned long	flags;
+	efi_time_t	eft;
+	efi_time_cap_t	cap;
+	struct rtc_time	wtime;
+
+	switch (cmd) {
+		case RTC_UIE_ON:
+		case RTC_UIE_OFF:
+		case RTC_PIE_ON:
+		case RTC_PIE_OFF:
+		case RTC_AIE_ON:
+		case RTC_AIE_OFF:
+		case RTC_ALM_SET:
+		case RTC_ALM_READ:
+		case RTC_IRQP_READ:
+		case RTC_IRQP_SET:
+		case RTC_EPOCH_READ:
+		case RTC_EPOCH_SET:
+			return -EINVAL;
+
+		case RTC_RD_TIME:
+
+			spin_lock_irqsave(&efi_rtc_lock, flags);
+
+			status = efi.get_time(&eft, &cap);
+
+			spin_unlock_irqrestore(&efi_rtc_lock,flags);
+
+			if (status != EFI_SUCCESS) {
+				/* should never happen */
+				printk(KERN_ERR "efitime: can't read time\n");
+				return -EINVAL;
+			}
+
+			convert_from_efi_time(&eft, &wtime);
+
+ 			return copy_to_user((void *)arg, &wtime, sizeof (struct rtc_time)) ? - EFAULT : 0;
+
+		case RTC_SET_TIME:
+
+			if (!capable(CAP_SYS_TIME)) return -EACCES;
+
+			if (copy_from_user(&wtime, (struct rtc_time *)arg, sizeof(struct rtc_time)) )
+				return -EFAULT;
+
+			convert_to_efi_time(&wtime, &eft);
+
+			spin_lock_irqsave(&efi_rtc_lock, flags);
+
+			status = efi.set_time(&eft);
+
+			spin_unlock_irqrestore(&efi_rtc_lock,flags);
+
+			return status == EFI_SUCCESS ? 0 : -EINVAL;
+	}
+	return -EINVAL;
+}
+
+/*
+ *	We enforce only one user at a time here with the open/close.
+ *	Also clear the previous interrupt data on an open, and clean
+ *	up things on a close.
+ */
+
+static int
+efi_rtc_open(struct inode *inode, struct file *file)
+{
+	/*
+	 * nothing special to do here
+	 * We do accept multiple open files at the same time as we
+	 * synchronize on the per call operation.
+	 */
+	return 0;
+}
+
+static int
+efi_rtc_close(struct inode *inode, struct file *file)
+{
+	return 0;
+}
+
+/*
+ *	The various file operations we support.
+ */
+
+static struct file_operations efi_rtc_fops = {
+	ioctl:		efi_rtc_ioctl,
+	open:		efi_rtc_open,
+	release:	efi_rtc_close,
+};
+
+static struct miscdevice efi_rtc_dev=
+{
+	EFI_RTC_MINOR,
+	"efirtc",
+	&efi_rtc_fops
+};
+
+/*
+ *	We export RAW EFI information to /proc/efirtc
+ */
+static int
+efi_rtc_get_status(char *buf)
+{
+	efi_time_t 	eft, alm;
+	efi_time_cap_t	cap;
+	char		*p = buf;
+	efi_bool_t	enabled, pending;	
+	unsigned long	flags;
+
+	spin_lock_irqsave(&efi_rtc_lock, flags);
+
+	efi.get_time(&eft, &cap);
+	efi.get_wakeup_time(&enabled, &pending, &alm);
+
+	spin_unlock_irqrestore(&efi_rtc_lock,flags);
+
+	p += sprintf(p,
+		     "Time      :\n"
+		     "Year      : %u\n"
+		     "Month     : %u\n"
+		     "Day       : %u\n"
+		     "Hour      : %u\n"
+		     "Minute    : %u\n"
+		     "Second    : %u\n"
+		     "Nanosecond: %u\n"
+		     "Daylight  : %u\n",
+		     eft.year, eft.month, eft.day, eft.hour, eft.minute,
+		     eft.second, eft.nanosecond, eft.daylight);
+
+	if ( eft.timezone == EFI_UNSPECIFIED_TIMEZONE)
+		p += sprintf(p, "Timezone  : unspecified\n");
+	else
+		/* XXX fixme: convert to string? */
+		p += sprintf(p, "Timezone  : %u\n", eft.timezone);
+		
+
+	p += sprintf(p,
+		     "\nWakeup Alm:\n"
+		     "Enabled   : %s\n"
+		     "Pending   : %s\n"
+		     "Year      : %u\n"
+		     "Month     : %u\n"
+		     "Day       : %u\n"
+		     "Hour      : %u\n"
+		     "Minute    : %u\n"
+		     "Second    : %u\n"
+		     "Nanosecond: %u\n"
+		     "Daylight  : %u\n",
+		     enabled == 1 ? "Yes" : "No",
+		     pending == 1 ? "Yes" : "No",
+		     alm.year, alm.month, alm.day, alm.hour, alm.minute,
+		     alm.second, alm.nanosecond, alm.daylight);
+
+	if ( eft.timezone == EFI_UNSPECIFIED_TIMEZONE)
+		p += sprintf(p, "Timezone  : unspecified\n");
+	else
+		/* XXX fixme: convert to string? */
+		p += sprintf(p, "Timezone  : %u\n", eft.timezone);
+
+	/*
+	 * now prints the capabilities
+	 */
+	p += sprintf(p,
+		     "\nClock Cap :\n"
+		     "Resolution: %u\n"
+		     "Accuracy  : %u\n"
+		     "SetstoZero: %u\n",
+		      cap.resolution, cap.accuracy, cap.sets_to_zero);
+
+	return  p - buf;
+}
+
+static int
+efi_rtc_read_proc(char *page, char **start, off_t off,
+                                 int count, int *eof, void *data)
+{
+        int len = efi_rtc_get_status(page);
+        if (len <= off+count) *eof = 1;
+        *start = page + off;
+        len -= off;
+        if (len>count) len = count;
+        if (len<0) len = 0;
+        return len;
+}
+static int __init 
+efi_rtc_init(void)
+{
+	printk(KERN_INFO "EFI Time Services Driver v%s\n", EFI_RTC_VERSION);
+
+	misc_register(&efi_rtc_dev);
+
+	create_proc_read_entry ("efirtc", 0, NULL, efi_rtc_read_proc, NULL);
+
+	return 0;
+}
+static int __exit
+efi_rtc_exit(void)
+{
+	/* not yet used */
+	return 0;
+}
+
+module_init(efi_rtc_init);
+module_exit(efi_rtc_exit);