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Diffstat (limited to 'drivers/char/efirtc.c')
-rw-r--r--drivers/char/efirtc.c417
1 files changed, 417 insertions, 0 deletions
diff --git a/drivers/char/efirtc.c b/drivers/char/efirtc.c
new file mode 100644
index 00000000000..0090e7a4fcd
--- /dev/null
+++ b/drivers/char/efirtc.c
@@ -0,0 +1,417 @@
+/*
+ * 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 an 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 to 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/module.h>
+#include <linux/init.h>
+#include <linux/rtc.h>
+#include <linux/proc_fs.h>
+#include <linux/efi.h>
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+#define EFI_RTC_VERSION "0.4"
+
+#define EFI_ISDST (EFI_TIME_ADJUST_DAYLIGHT|EFI_TIME_IN_DAYLIGHT)
+/*
+ * EFI Epoch is 1/1/1998
+ */
+#define EFI_RTC_EPOCH 1998
+
+static DEFINE_SPINLOCK(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)
+{
+ memset(wtime, 0, sizeof(*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;
+ struct rtc_wkalrm __user *ewp;
+ unsigned char enabled, pending;
+
+ 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 __user *)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 __user *)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;
+
+ case RTC_WKALM_SET:
+
+ if (!capable(CAP_SYS_TIME)) return -EACCES;
+
+ ewp = (struct rtc_wkalrm __user *)arg;
+
+ if ( get_user(enabled, &ewp->enabled)
+ || copy_from_user(&wtime, &ewp->time, sizeof(struct rtc_time)) )
+ return -EFAULT;
+
+ convert_to_efi_time(&wtime, &eft);
+
+ spin_lock_irqsave(&efi_rtc_lock, flags);
+ /*
+ * XXX Fixme:
+ * As of EFI 0.92 with the firmware I have on my
+ * machine this call does not seem to work quite
+ * right
+ */
+ status = efi.set_wakeup_time((efi_bool_t)enabled, &eft);
+
+ spin_unlock_irqrestore(&efi_rtc_lock,flags);
+
+ return status == EFI_SUCCESS ? 0 : -EINVAL;
+
+ case RTC_WKALM_RD:
+
+ spin_lock_irqsave(&efi_rtc_lock, flags);
+
+ status = efi.get_wakeup_time((efi_bool_t *)&enabled, (efi_bool_t *)&pending, &eft);
+
+ spin_unlock_irqrestore(&efi_rtc_lock,flags);
+
+ if (status != EFI_SUCCESS) return -EINVAL;
+
+ ewp = (struct rtc_wkalrm __user *)arg;
+
+ if ( put_user(enabled, &ewp->enabled)
+ || put_user(pending, &ewp->pending)) return -EFAULT;
+
+ convert_from_efi_time(&eft, &wtime);
+
+ return copy_to_user(&ewp->time, &wtime,
+ sizeof(struct rtc_time)) ? -EFAULT : 0;
+ }
+ 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 = {
+ .owner = THIS_MODULE,
+ .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/driver/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;
+
+ memset(&eft, 0, sizeof(eft));
+ memset(&alm, 0, sizeof(alm));
+ memset(&cap, 0, sizeof(cap));
+
+ 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 : %u:%u:%u.%09u\n"
+ "Date : %u-%u-%u\n"
+ "Daylight : %u\n",
+ eft.hour, eft.minute, eft.second, eft.nanosecond,
+ eft.year, eft.month, eft.day,
+ 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,
+ "Alarm Time : %u:%u:%u.%09u\n"
+ "Alarm Date : %u-%u-%u\n"
+ "Alarm Daylight : %u\n"
+ "Enabled : %s\n"
+ "Pending : %s\n",
+ alm.hour, alm.minute, alm.second, alm.nanosecond,
+ alm.year, alm.month, alm.day,
+ alm.daylight,
+ enabled == 1 ? "yes" : "no",
+ pending == 1 ? "yes" : "no");
+
+ if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE)
+ p += sprintf(p, "Timezone : unspecified\n");
+ else
+ /* XXX fixme: convert to string? */
+ p += sprintf(p, "Timezone : %u\n", alm.timezone);
+
+ /*
+ * now prints the capabilities
+ */
+ p += sprintf(p,
+ "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)
+{
+ int ret;
+ struct proc_dir_entry *dir;
+
+ printk(KERN_INFO "EFI Time Services Driver v%s\n", EFI_RTC_VERSION);
+
+ ret = misc_register(&efi_rtc_dev);
+ if (ret) {
+ printk(KERN_ERR "efirtc: can't misc_register on minor=%d\n",
+ EFI_RTC_MINOR);
+ return ret;
+ }
+
+ dir = create_proc_read_entry ("driver/efirtc", 0, NULL,
+ efi_rtc_read_proc, NULL);
+ if (dir == NULL) {
+ printk(KERN_ERR "efirtc: can't create /proc/driver/efirtc.\n");
+ misc_deregister(&efi_rtc_dev);
+ return -1;
+ }
+ return 0;
+}
+
+static void __exit
+efi_rtc_exit(void)
+{
+ /* not yet used */
+}
+
+module_init(efi_rtc_init);
+module_exit(efi_rtc_exit);
+
+MODULE_LICENSE("GPL");
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-24 13:54:10 +0000