2 * Real Time Clock interface for PPC64.
4 * Based on rtc.c by Paul Gortmaker
6 * This driver allows use of the real time clock
7 * from user space. It exports the /dev/rtc
8 * interface supporting various ioctl() and also the
9 * /proc/driver/rtc pseudo-file for status information.
11 * Interface does not support RTC interrupts nor an alarm.
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License
15 * as published by the Free Software Foundation; either version
16 * 2 of the License, or (at your option) any later version.
18 * 1.0 Mike Corrigan: IBM iSeries rtc support
19 * 1.1 Dave Engebretsen: IBM pSeries rtc support
22 #define RTC_VERSION "1.1"
24 #include <linux/config.h>
25 #include <linux/module.h>
26 #include <linux/kernel.h>
27 #include <linux/types.h>
28 #include <linux/miscdevice.h>
29 #include <linux/ioport.h>
30 #include <linux/fcntl.h>
31 #include <linux/mc146818rtc.h>
32 #include <linux/init.h>
33 #include <linux/poll.h>
34 #include <linux/proc_fs.h>
35 #include <linux/spinlock.h>
36 #include <linux/bcd.h>
38 #include <asm/hardirq.h>
40 #include <asm/uaccess.h>
41 #include <asm/system.h>
45 #include <asm/iSeries/LparData.h>
46 #include <asm/iSeries/mf.h>
47 #include <asm/machdep.h>
48 #include <asm/iSeries/ItSpCommArea.h>
50 extern int piranha_simulator;
53 * We sponge a minor off of the misc major. No need slurping
54 * up another valuable major dev number for this. If you add
55 * an ioctl, make sure you don't conflict with SPARC's RTC
59 static loff_t rtc_llseek(struct file *file, loff_t offset, int origin);
61 static ssize_t rtc_read(struct file *file, char *buf,
62 size_t count, loff_t *ppos);
64 static int rtc_ioctl(struct inode *inode, struct file *file,
65 unsigned int cmd, unsigned long arg);
67 static int rtc_read_proc(char *page, char **start, off_t off,
68 int count, int *eof, void *data);
71 * If this driver ever becomes modularised, it will be really nice
72 * to make the epoch retain its value across module reload...
75 static unsigned long epoch = 1900; /* year corresponding to 0x00 */
77 static const unsigned char days_in_mo[] =
78 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
81 * Now all the various file operations that we export.
84 static loff_t rtc_llseek(struct file *file, loff_t offset, int origin)
89 static ssize_t rtc_read(struct file *file, char *buf,
90 size_t count, loff_t *ppos)
95 static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
98 struct rtc_time wtime;
101 case RTC_RD_TIME: /* Read the time/date from RTC */
103 memset(&wtime, 0, sizeof(struct rtc_time));
104 ppc_md.get_rtc_time(&wtime);
107 case RTC_SET_TIME: /* Set the RTC */
109 struct rtc_time rtc_tm;
110 unsigned char mon, day, hrs, min, sec, leap_yr;
113 if (!capable(CAP_SYS_TIME))
116 if (copy_from_user(&rtc_tm, (struct rtc_time*)arg,
117 sizeof(struct rtc_time)))
120 yrs = rtc_tm.tm_year;
121 mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
122 day = rtc_tm.tm_mday;
123 hrs = rtc_tm.tm_hour;
130 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
132 if ((mon > 12) || (day == 0))
135 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
138 if ((hrs >= 24) || (min >= 60) || (sec >= 60))
144 ppc_md.set_rtc_time(&rtc_tm);
148 case RTC_EPOCH_READ: /* Read the epoch. */
150 return put_user (epoch, (unsigned long *)arg);
152 case RTC_EPOCH_SET: /* Set the epoch. */
155 * There were no RTC clocks before 1900.
160 if (!capable(CAP_SYS_TIME))
169 return copy_to_user((void *)arg, &wtime, sizeof wtime) ? -EFAULT : 0;
172 static int rtc_open(struct inode *inode, struct file *file)
177 static int rtc_release(struct inode *inode, struct file *file)
183 * The various file operations we support.
185 static struct file_operations rtc_fops = {
186 .owner = THIS_MODULE,
187 .llseek = rtc_llseek,
191 .release = rtc_release,
194 static struct miscdevice rtc_dev=
201 static int __init rtc_init(void)
205 retval = misc_register(&rtc_dev);
209 #ifdef CONFIG_PROC_FS
210 if(create_proc_read_entry ("driver/rtc", 0, 0, rtc_read_proc, NULL) == NULL)
211 misc_deregister(&rtc_dev);
215 printk(KERN_INFO "i/pSeries Real Time Clock Driver v" RTC_VERSION "\n");
220 static void __exit rtc_exit (void)
222 remove_proc_entry ("driver/rtc", NULL);
223 misc_deregister(&rtc_dev);
226 module_init(rtc_init);
227 module_exit(rtc_exit);
230 * Info exported via "/proc/driver/rtc".
233 static int rtc_proc_output (char *buf)
241 ppc_md.get_rtc_time(&tm);
244 * There is no way to tell if the luser has the RTC set for local
245 * time or for Universal Standard Time (GMT). Probably local though.
248 "rtc_time\t: %02d:%02d:%02d\n"
249 "rtc_date\t: %04d-%02d-%02d\n"
250 "rtc_epoch\t: %04lu\n",
251 tm.tm_hour, tm.tm_min, tm.tm_sec,
252 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch);
262 static int rtc_read_proc(char *page, char **start, off_t off,
263 int count, int *eof, void *data)
265 int len = rtc_proc_output (page);
266 if (len <= off+count) *eof = 1;
269 if (len>count) len = count;
274 #ifdef CONFIG_PPC_ISERIES
276 * Get the RTC from the virtual service processor
277 * This requires flowing LpEvents to the primary partition
279 void iSeries_get_rtc_time(struct rtc_time *rtc_tm)
281 if (piranha_simulator)
289 * Set the RTC in the virtual service processor
290 * This requires flowing LpEvents to the primary partition
292 int iSeries_set_rtc_time(struct rtc_time *tm)
298 void iSeries_get_boot_time(struct rtc_time *tm)
301 static unsigned long lastsec = 1;
303 u32 dataWord1 = *((u32 *)(&xSpCommArea.xBcdTimeAtIplStart));
304 u32 dataWord2 = *(((u32 *)&(xSpCommArea.xBcdTimeAtIplStart)) + 1);
306 int year1 = ( dataWord1 >> 24 ) & 0x000000FF;
307 int year2 = ( dataWord1 >> 16 ) & 0x000000FF;
308 int sec = ( dataWord1 >> 8 ) & 0x000000FF;
309 int min = dataWord1 & 0x000000FF;
310 int hour = ( dataWord2 >> 24 ) & 0x000000FF;
311 int day = ( dataWord2 >> 8 ) & 0x000000FF;
312 int mon = dataWord2 & 0x000000FF;
314 if ( piranha_simulator )
324 year = year1 * 100 + year2;
326 time = mktime(year, mon, day, hour, min, sec);
327 time += ( jiffies / HZ );
329 /* Now THIS is a nasty hack!
330 * It ensures that the first two calls get different answers.
331 * That way the loop in init_time (time.c) will not think
332 * the clock is stuck.
345 #ifdef CONFIG_PPC_PSERIES
346 #define MAX_RTC_WAIT 5000 /* 5 sec */
347 #define RTAS_CLOCK_BUSY (-2)
348 void pSeries_get_boot_time(struct rtc_time *rtc_tm)
351 int error, wait_time;
352 unsigned long max_wait_tb;
354 max_wait_tb = __get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
356 error = rtas_call(rtas_token("get-time-of-day"), 0, 8, ret);
357 if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) {
358 wait_time = rtas_extended_busy_delay_time(error);
359 /* This is boot time so we spin. */
360 udelay(wait_time*1000);
361 error = RTAS_CLOCK_BUSY;
363 } while (error == RTAS_CLOCK_BUSY && (__get_tb() < max_wait_tb));
366 printk(KERN_WARNING "error: reading the clock failed (%d)\n",
371 rtc_tm->tm_sec = ret[5];
372 rtc_tm->tm_min = ret[4];
373 rtc_tm->tm_hour = ret[3];
374 rtc_tm->tm_mday = ret[2];
375 rtc_tm->tm_mon = ret[1] - 1;
376 rtc_tm->tm_year = ret[0] - 1900;
379 /* NOTE: get_rtc_time will get an error if executed in interrupt context
380 * and if a delay is needed to read the clock. In this case we just
381 * silently return without updating rtc_tm.
383 void pSeries_get_rtc_time(struct rtc_time *rtc_tm)
386 int error, wait_time;
387 unsigned long max_wait_tb;
389 max_wait_tb = __get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
391 error = rtas_call(rtas_token("get-time-of-day"), 0, 8, ret);
392 if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) {
393 if (in_interrupt()) {
394 printk(KERN_WARNING "error: reading clock would delay interrupt\n");
395 return; /* delay not allowed */
397 wait_time = rtas_extended_busy_delay_time(error);
398 set_current_state(TASK_INTERRUPTIBLE);
399 schedule_timeout(wait_time);
400 error = RTAS_CLOCK_BUSY;
402 } while (error == RTAS_CLOCK_BUSY && (__get_tb() < max_wait_tb));
405 printk(KERN_WARNING "error: reading the clock failed (%d)\n",
410 rtc_tm->tm_sec = ret[5];
411 rtc_tm->tm_min = ret[4];
412 rtc_tm->tm_hour = ret[3];
413 rtc_tm->tm_mday = ret[2];
414 rtc_tm->tm_mon = ret[1] - 1;
415 rtc_tm->tm_year = ret[0] - 1900;
418 int pSeries_set_rtc_time(struct rtc_time *tm)
420 int error, wait_time;
421 unsigned long max_wait_tb;
423 max_wait_tb = __get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
425 error = rtas_call(rtas_token("set-time-of-day"), 7, 1, NULL,
426 tm->tm_year + 1900, tm->tm_mon + 1,
427 tm->tm_mday, tm->tm_hour, tm->tm_min,
429 if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) {
431 return 1; /* probably decrementer */
432 wait_time = rtas_extended_busy_delay_time(error);
433 set_current_state(TASK_INTERRUPTIBLE);
434 schedule_timeout(wait_time);
435 error = RTAS_CLOCK_BUSY;
437 } while (error == RTAS_CLOCK_BUSY && (__get_tb() < max_wait_tb));
440 printk(KERN_WARNING "error: setting the clock failed (%d)\n",