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401 lines
9.4 KiB
401 lines
9.4 KiB
/*
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* Real Time Clock interface for PPC64.
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*
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* Based on rtc.c by Paul Gortmaker
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*
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* This driver allows use of the real time clock
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* from user space. It exports the /dev/rtc
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* interface supporting various ioctl() and also the
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* /proc/driver/rtc pseudo-file for status information.
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*
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* Interface does not support RTC interrupts nor an alarm.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* 1.0 Mike Corrigan: IBM iSeries rtc support
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* 1.1 Dave Engebretsen: IBM pSeries rtc support
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*/
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#define RTC_VERSION "1.1"
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#include <linux/config.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/miscdevice.h>
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#include <linux/ioport.h>
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#include <linux/fcntl.h>
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#include <linux/mc146818rtc.h>
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#include <linux/init.h>
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#include <linux/poll.h>
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#include <linux/proc_fs.h>
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#include <linux/spinlock.h>
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#include <linux/bcd.h>
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#include <linux/interrupt.h>
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#include <asm/io.h>
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#include <asm/uaccess.h>
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#include <asm/system.h>
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#include <asm/time.h>
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#include <asm/rtas.h>
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#include <asm/iSeries/mf.h>
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#include <asm/machdep.h>
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extern int piranha_simulator;
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/*
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* We sponge a minor off of the misc major. No need slurping
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* up another valuable major dev number for this. If you add
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* an ioctl, make sure you don't conflict with SPARC's RTC
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* ioctls.
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*/
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static ssize_t rtc_read(struct file *file, char __user *buf,
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size_t count, loff_t *ppos);
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static int rtc_ioctl(struct inode *inode, struct file *file,
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unsigned int cmd, unsigned long arg);
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static int rtc_read_proc(char *page, char **start, off_t off,
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int count, int *eof, void *data);
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/*
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* If this driver ever becomes modularised, it will be really nice
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* to make the epoch retain its value across module reload...
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*/
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static unsigned long epoch = 1900; /* year corresponding to 0x00 */
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static const unsigned char days_in_mo[] =
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{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
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/*
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* Now all the various file operations that we export.
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*/
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static ssize_t rtc_read(struct file *file, char __user *buf,
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size_t count, loff_t *ppos)
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{
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return -EIO;
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}
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static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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struct rtc_time wtime;
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switch (cmd) {
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case RTC_RD_TIME: /* Read the time/date from RTC */
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{
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memset(&wtime, 0, sizeof(struct rtc_time));
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ppc_md.get_rtc_time(&wtime);
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break;
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}
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case RTC_SET_TIME: /* Set the RTC */
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{
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struct rtc_time rtc_tm;
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unsigned char mon, day, hrs, min, sec, leap_yr;
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unsigned int yrs;
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if (!capable(CAP_SYS_TIME))
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return -EACCES;
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if (copy_from_user(&rtc_tm, (struct rtc_time __user *)arg,
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sizeof(struct rtc_time)))
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return -EFAULT;
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yrs = rtc_tm.tm_year;
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mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
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day = rtc_tm.tm_mday;
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hrs = rtc_tm.tm_hour;
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min = rtc_tm.tm_min;
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sec = rtc_tm.tm_sec;
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if (yrs < 70)
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return -EINVAL;
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leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
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if ((mon > 12) || (day == 0))
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return -EINVAL;
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if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
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return -EINVAL;
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if ((hrs >= 24) || (min >= 60) || (sec >= 60))
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return -EINVAL;
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if ( yrs > 169 )
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return -EINVAL;
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ppc_md.set_rtc_time(&rtc_tm);
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return 0;
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}
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case RTC_EPOCH_READ: /* Read the epoch. */
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{
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return put_user (epoch, (unsigned long __user *)arg);
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}
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case RTC_EPOCH_SET: /* Set the epoch. */
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{
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/*
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* There were no RTC clocks before 1900.
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*/
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if (arg < 1900)
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return -EINVAL;
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if (!capable(CAP_SYS_TIME))
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return -EACCES;
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epoch = arg;
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return 0;
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}
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default:
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return -EINVAL;
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}
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return copy_to_user((void __user *)arg, &wtime, sizeof wtime) ? -EFAULT : 0;
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}
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static int rtc_open(struct inode *inode, struct file *file)
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{
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nonseekable_open(inode, file);
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return 0;
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}
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static int rtc_release(struct inode *inode, struct file *file)
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{
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return 0;
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}
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/*
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* The various file operations we support.
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*/
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static struct file_operations rtc_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.read = rtc_read,
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.ioctl = rtc_ioctl,
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.open = rtc_open,
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.release = rtc_release,
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};
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static struct miscdevice rtc_dev = {
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.minor = RTC_MINOR,
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.name = "rtc",
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.fops = &rtc_fops
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};
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static int __init rtc_init(void)
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{
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int retval;
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retval = misc_register(&rtc_dev);
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if(retval < 0)
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return retval;
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#ifdef CONFIG_PROC_FS
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if (create_proc_read_entry("driver/rtc", 0, NULL, rtc_read_proc, NULL)
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== NULL) {
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misc_deregister(&rtc_dev);
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return -ENOMEM;
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}
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#endif
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printk(KERN_INFO "i/pSeries Real Time Clock Driver v" RTC_VERSION "\n");
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return 0;
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}
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static void __exit rtc_exit (void)
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{
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remove_proc_entry ("driver/rtc", NULL);
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misc_deregister(&rtc_dev);
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}
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module_init(rtc_init);
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module_exit(rtc_exit);
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/*
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* Info exported via "/proc/driver/rtc".
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*/
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static int rtc_proc_output (char *buf)
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{
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char *p;
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struct rtc_time tm;
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p = buf;
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ppc_md.get_rtc_time(&tm);
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/*
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* There is no way to tell if the luser has the RTC set for local
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* time or for Universal Standard Time (GMT). Probably local though.
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*/
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p += sprintf(p,
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"rtc_time\t: %02d:%02d:%02d\n"
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"rtc_date\t: %04d-%02d-%02d\n"
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"rtc_epoch\t: %04lu\n",
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tm.tm_hour, tm.tm_min, tm.tm_sec,
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tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch);
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p += sprintf(p,
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"DST_enable\t: no\n"
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"BCD\t\t: yes\n"
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"24hr\t\t: yes\n" );
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return p - buf;
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}
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static int rtc_read_proc(char *page, char **start, off_t off,
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int count, int *eof, void *data)
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{
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int len = rtc_proc_output (page);
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if (len <= off+count) *eof = 1;
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*start = page + off;
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len -= off;
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if (len>count) len = count;
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if (len<0) len = 0;
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return len;
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}
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#ifdef CONFIG_PPC_ISERIES
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/*
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* Get the RTC from the virtual service processor
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* This requires flowing LpEvents to the primary partition
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*/
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void iSeries_get_rtc_time(struct rtc_time *rtc_tm)
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{
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if (piranha_simulator)
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return;
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mf_get_rtc(rtc_tm);
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rtc_tm->tm_mon--;
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}
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/*
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* Set the RTC in the virtual service processor
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* This requires flowing LpEvents to the primary partition
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*/
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int iSeries_set_rtc_time(struct rtc_time *tm)
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{
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mf_set_rtc(tm);
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return 0;
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}
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void iSeries_get_boot_time(struct rtc_time *tm)
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{
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if ( piranha_simulator )
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return;
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mf_get_boot_rtc(tm);
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tm->tm_mon -= 1;
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}
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#endif
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#ifdef CONFIG_PPC_RTAS
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#define MAX_RTC_WAIT 5000 /* 5 sec */
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#define RTAS_CLOCK_BUSY (-2)
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void pSeries_get_boot_time(struct rtc_time *rtc_tm)
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{
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int ret[8];
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int error, wait_time;
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unsigned long max_wait_tb;
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max_wait_tb = __get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
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do {
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error = rtas_call(rtas_token("get-time-of-day"), 0, 8, ret);
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if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) {
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wait_time = rtas_extended_busy_delay_time(error);
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/* This is boot time so we spin. */
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udelay(wait_time*1000);
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error = RTAS_CLOCK_BUSY;
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}
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} while (error == RTAS_CLOCK_BUSY && (__get_tb() < max_wait_tb));
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if (error != 0 && printk_ratelimit()) {
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printk(KERN_WARNING "error: reading the clock failed (%d)\n",
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error);
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return;
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}
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rtc_tm->tm_sec = ret[5];
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rtc_tm->tm_min = ret[4];
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rtc_tm->tm_hour = ret[3];
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rtc_tm->tm_mday = ret[2];
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rtc_tm->tm_mon = ret[1] - 1;
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rtc_tm->tm_year = ret[0] - 1900;
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}
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/* NOTE: get_rtc_time will get an error if executed in interrupt context
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* and if a delay is needed to read the clock. In this case we just
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* silently return without updating rtc_tm.
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*/
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void pSeries_get_rtc_time(struct rtc_time *rtc_tm)
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{
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int ret[8];
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int error, wait_time;
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unsigned long max_wait_tb;
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max_wait_tb = __get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
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do {
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error = rtas_call(rtas_token("get-time-of-day"), 0, 8, ret);
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if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) {
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if (in_interrupt() && printk_ratelimit()) {
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printk(KERN_WARNING "error: reading clock would delay interrupt\n");
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return; /* delay not allowed */
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}
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wait_time = rtas_extended_busy_delay_time(error);
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set_current_state(TASK_INTERRUPTIBLE);
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schedule_timeout(wait_time);
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error = RTAS_CLOCK_BUSY;
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}
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} while (error == RTAS_CLOCK_BUSY && (__get_tb() < max_wait_tb));
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if (error != 0 && printk_ratelimit()) {
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printk(KERN_WARNING "error: reading the clock failed (%d)\n",
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error);
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return;
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}
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rtc_tm->tm_sec = ret[5];
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rtc_tm->tm_min = ret[4];
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rtc_tm->tm_hour = ret[3];
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rtc_tm->tm_mday = ret[2];
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rtc_tm->tm_mon = ret[1] - 1;
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rtc_tm->tm_year = ret[0] - 1900;
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}
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int pSeries_set_rtc_time(struct rtc_time *tm)
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{
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int error, wait_time;
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unsigned long max_wait_tb;
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max_wait_tb = __get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
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do {
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error = rtas_call(rtas_token("set-time-of-day"), 7, 1, NULL,
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tm->tm_year + 1900, tm->tm_mon + 1,
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tm->tm_mday, tm->tm_hour, tm->tm_min,
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tm->tm_sec, 0);
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if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) {
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if (in_interrupt())
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return 1; /* probably decrementer */
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wait_time = rtas_extended_busy_delay_time(error);
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set_current_state(TASK_INTERRUPTIBLE);
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schedule_timeout(wait_time);
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error = RTAS_CLOCK_BUSY;
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}
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} while (error == RTAS_CLOCK_BUSY && (__get_tb() < max_wait_tb));
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if (error != 0 && printk_ratelimit())
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printk(KERN_WARNING "error: setting the clock failed (%d)\n",
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error);
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return 0;
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}
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#endif
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