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>
44 #include <asm/iSeries/LparData.h>
45 #include <asm/iSeries/mf.h>
46 #include <asm/machdep.h>
47 #include <asm/iSeries/ItSpCommArea.h>
49 extern int piranha_simulator;
52 * We sponge a minor off of the misc major. No need slurping
53 * up another valuable major dev number for this. If you add
54 * an ioctl, make sure you don't conflict with SPARC's RTC
58 static loff_t rtc_llseek(struct file *file, loff_t offset, int origin);
60 static ssize_t rtc_read(struct file *file, char *buf,
61 size_t count, loff_t *ppos);
63 static int rtc_ioctl(struct inode *inode, struct file *file,
64 unsigned int cmd, unsigned long arg);
66 static int rtc_read_proc(char *page, char **start, off_t off,
67 int count, int *eof, void *data);
70 * If this driver ever becomes modularised, it will be really nice
71 * to make the epoch retain its value across module reload...
74 static unsigned long epoch = 1900; /* year corresponding to 0x00 */
76 static const unsigned char days_in_mo[] =
77 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
80 * Now all the various file operations that we export.
83 static loff_t rtc_llseek(struct file *file, loff_t offset, int origin)
88 static ssize_t rtc_read(struct file *file, char *buf,
89 size_t count, loff_t *ppos)
94 static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
97 struct rtc_time wtime;
100 case RTC_RD_TIME: /* Read the time/date from RTC */
102 memset(&wtime, 0, sizeof(struct rtc_time));
103 ppc_md.get_rtc_time(&wtime);
106 case RTC_SET_TIME: /* Set the RTC */
108 struct rtc_time rtc_tm;
109 unsigned char mon, day, hrs, min, sec, leap_yr;
112 if (!capable(CAP_SYS_TIME))
115 if (copy_from_user(&rtc_tm, (struct rtc_time*)arg,
116 sizeof(struct rtc_time)))
119 yrs = rtc_tm.tm_year;
120 mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
121 day = rtc_tm.tm_mday;
122 hrs = rtc_tm.tm_hour;
129 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
131 if ((mon > 12) || (day == 0))
134 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
137 if ((hrs >= 24) || (min >= 60) || (sec >= 60))
143 ppc_md.set_rtc_time(&rtc_tm);
147 case RTC_EPOCH_READ: /* Read the epoch. */
149 return put_user (epoch, (unsigned long *)arg);
151 case RTC_EPOCH_SET: /* Set the epoch. */
154 * There were no RTC clocks before 1900.
159 if (!capable(CAP_SYS_TIME))
168 return copy_to_user((void *)arg, &wtime, sizeof wtime) ? -EFAULT : 0;
171 static int rtc_open(struct inode *inode, struct file *file)
176 static int rtc_release(struct inode *inode, struct file *file)
182 * The various file operations we support.
184 static struct file_operations rtc_fops = {
185 .owner = THIS_MODULE,
186 .llseek = rtc_llseek,
190 .release = rtc_release,
193 static struct miscdevice rtc_dev=
200 static int __init rtc_init(void)
204 retval = misc_register(&rtc_dev);
208 #ifdef CONFIG_PROC_FS
209 if(create_proc_read_entry ("driver/rtc", 0, 0, rtc_read_proc, NULL) == NULL)
210 misc_deregister(&rtc_dev);
214 printk(KERN_INFO "i/pSeries Real Time Clock Driver v" RTC_VERSION "\n");
219 static void __exit rtc_exit (void)
221 remove_proc_entry ("driver/rtc", NULL);
222 misc_deregister(&rtc_dev);
225 module_init(rtc_init);
226 module_exit(rtc_exit);
229 * Info exported via "/proc/driver/rtc".
232 static int rtc_proc_output (char *buf)
240 ppc_md.get_rtc_time(&tm);
243 * There is no way to tell if the luser has the RTC set for local
244 * time or for Universal Standard Time (GMT). Probably local though.
247 "rtc_time\t: %02d:%02d:%02d\n"
248 "rtc_date\t: %04d-%02d-%02d\n"
249 "rtc_epoch\t: %04lu\n",
250 tm.tm_hour, tm.tm_min, tm.tm_sec,
251 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch);
261 static int rtc_read_proc(char *page, char **start, off_t off,
262 int count, int *eof, void *data)
264 int len = rtc_proc_output (page);
265 if (len <= off+count) *eof = 1;
268 if (len>count) len = count;
273 #ifdef CONFIG_PPC_ISERIES
275 * Get the RTC from the virtual service processor
276 * This requires flowing LpEvents to the primary partition
278 void iSeries_get_rtc_time(struct rtc_time *rtc_tm)
280 if (piranha_simulator)
288 * Set the RTC in the virtual service processor
289 * This requires flowing LpEvents to the primary partition
291 int iSeries_set_rtc_time(struct rtc_time *tm)
297 void iSeries_get_boot_time(struct rtc_time *tm)
300 static unsigned long lastsec = 1;
302 u32 dataWord1 = *((u32 *)(&xSpCommArea.xBcdTimeAtIplStart));
303 u32 dataWord2 = *(((u32 *)&(xSpCommArea.xBcdTimeAtIplStart)) + 1);
305 int year1 = ( dataWord1 >> 24 ) & 0x000000FF;
306 int year2 = ( dataWord1 >> 16 ) & 0x000000FF;
307 int sec = ( dataWord1 >> 8 ) & 0x000000FF;
308 int min = dataWord1 & 0x000000FF;
309 int hour = ( dataWord2 >> 24 ) & 0x000000FF;
310 int day = ( dataWord2 >> 8 ) & 0x000000FF;
311 int mon = dataWord2 & 0x000000FF;
313 if ( piranha_simulator )
323 year = year1 * 100 + year2;
325 time = mktime(year, mon, day, hour, min, sec);
326 time += ( jiffies / HZ );
328 /* Now THIS is a nasty hack!
329 * It ensures that the first two calls get different answers.
330 * That way the loop in init_time (time.c) will not think
331 * the clock is stuck.
344 #ifdef CONFIG_PPC_PSERIES
345 #define MAX_RTC_WAIT 5000 /* 5 sec */
346 #define RTAS_CLOCK_BUSY (-2)
347 void pSeries_get_boot_time(struct rtc_time *rtc_tm)
349 unsigned long ret[8];
350 int error, wait_time;
351 unsigned long max_wait_tb;
353 max_wait_tb = __get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
355 error = rtas_call(rtas_token("get-time-of-day"), 0, 8, (void *)&ret);
356 if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) {
357 wait_time = rtas_extended_busy_delay_time(error);
358 /* This is boot time so we spin. */
359 udelay(wait_time*1000);
360 error = RTAS_CLOCK_BUSY;
362 } while (error == RTAS_CLOCK_BUSY && (__get_tb() < max_wait_tb));
365 printk(KERN_WARNING "error: reading the clock failed (%d)\n",
370 rtc_tm->tm_sec = ret[5];
371 rtc_tm->tm_min = ret[4];
372 rtc_tm->tm_hour = ret[3];
373 rtc_tm->tm_mday = ret[2];
374 rtc_tm->tm_mon = ret[1] - 1;
375 rtc_tm->tm_year = ret[0] - 1900;
378 /* NOTE: get_rtc_time will get an error if executed in interrupt context
379 * and if a delay is needed to read the clock. In this case we just
380 * silently return without updating rtc_tm.
382 void pSeries_get_rtc_time(struct rtc_time *rtc_tm)
384 unsigned long ret[8];
385 int error, wait_time;
386 unsigned long max_wait_tb;
388 max_wait_tb = __get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
390 error = rtas_call(rtas_token("get-time-of-day"), 0, 8, (void *)&ret);
391 if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) {
392 if (in_interrupt()) {
393 printk(KERN_WARNING "error: reading clock would delay interrupt\n");
394 return; /* delay not allowed */
396 wait_time = rtas_extended_busy_delay_time(error);
397 set_current_state(TASK_INTERRUPTIBLE);
398 schedule_timeout(wait_time);
399 error = RTAS_CLOCK_BUSY;
401 } while (error == RTAS_CLOCK_BUSY && (__get_tb() < max_wait_tb));
404 printk(KERN_WARNING "error: reading the clock failed (%d)\n",
409 rtc_tm->tm_sec = ret[5];
410 rtc_tm->tm_min = ret[4];
411 rtc_tm->tm_hour = ret[3];
412 rtc_tm->tm_mday = ret[2];
413 rtc_tm->tm_mon = ret[1] - 1;
414 rtc_tm->tm_year = ret[0] - 1900;
417 int pSeries_set_rtc_time(struct rtc_time *tm)
419 int error, wait_time;
420 unsigned long max_wait_tb;
422 max_wait_tb = __get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
424 error = rtas_call(rtas_token("set-time-of-day"), 7, 1, NULL,
425 tm->tm_year + 1900, tm->tm_mon + 1,
426 tm->tm_mday, tm->tm_hour, tm->tm_min,
428 if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) {
430 return 1; /* probably decrementer */
431 wait_time = rtas_extended_busy_delay_time(error);
432 set_current_state(TASK_INTERRUPTIBLE);
433 schedule_timeout(wait_time);
434 error = RTAS_CLOCK_BUSY;
436 } while (error == RTAS_CLOCK_BUSY && (__get_tb() < max_wait_tb));
439 printk(KERN_WARNING "error: setting the clock failed (%d)\n",