1 /*
2 * Real Time Clock interface for PPC64.
3 *
4 * Based on rtc.c by Paul Gortmaker
5 *
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.
10 *
11 * Interface does not support RTC interrupts nor an alarm.
12 *
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.
17 *
18 * 1.0 Mike Corrigan: IBM iSeries rtc support
19 * 1.1 Dave Engebretsen: IBM pSeries rtc support
20 */
21
22 #define RTC_VERSION "1.1"
23
24 #include <linux/module.h>
25 #include <linux/kernel.h>
26 #include <linux/types.h>
27 #include <linux/miscdevice.h>
28 #include <linux/ioport.h>
29 #include <linux/fcntl.h>
30 #include <linux/mc146818rtc.h>
31 #include <linux/init.h>
32 #include <linux/poll.h>
33 #include <linux/proc_fs.h>
34 #include <linux/spinlock.h>
35
36 #include <asm/hardirq.h>
37 #include <asm/io.h>
38 #include <asm/uaccess.h>
39 #include <asm/system.h>
40 #include <asm/time.h>
41
42 #include <asm/iSeries/LparData.h>
43 #include <asm/iSeries/mf.h>
44 #include <asm/machdep.h>
45 #include <asm/iSeries/ItSpCommArea.h>
46
47 extern int piranha_simulator;
48
49 /*
50 * We sponge a minor off of the misc major. No need slurping
51 * up another valuable major dev number for this. If you add
52 * an ioctl, make sure you don't conflict with SPARC's RTC
53 * ioctls.
54 */
55
56 static loff_t rtc_llseek(struct file *file, loff_t offset, int origin);
57
58 static ssize_t rtc_read(struct file *file, char *buf,
59 size_t count, loff_t *ppos);
60
61 static int rtc_ioctl(struct inode *inode, struct file *file,
62 unsigned int cmd, unsigned long arg);
63
64 static int rtc_read_proc(char *page, char **start, off_t off,
65 int count, int *eof, void *data);
66
67 /*
68 * If this driver ever becomes modularised, it will be really nice
69 * to make the epoch retain its value across module reload...
70 */
71
72 static unsigned long epoch = 1900; /* year corresponding to 0x00 */
73
74 static const unsigned char days_in_mo[] =
75 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
76
77 /*
78 * Now all the various file operations that we export.
79 */
80
rtc_llseek(struct file * file,loff_t offset,int origin)81 static loff_t rtc_llseek(struct file *file, loff_t offset, int origin)
82 {
83 return -ESPIPE;
84 }
85
rtc_read(struct file * file,char * buf,size_t count,loff_t * ppos)86 static ssize_t rtc_read(struct file *file, char *buf,
87 size_t count, loff_t *ppos)
88 {
89 return -EIO;
90 }
91
rtc_ioctl(struct inode * inode,struct file * file,unsigned int cmd,unsigned long arg)92 static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
93 unsigned long arg)
94 {
95 struct rtc_time wtime;
96
97 switch (cmd) {
98 case RTC_RD_TIME: /* Read the time/date from RTC */
99 {
100 memset(&wtime, 0, sizeof(struct rtc_time));
101 ppc_md.get_rtc_time(&wtime);
102 break;
103 }
104 case RTC_SET_TIME: /* Set the RTC */
105 {
106 struct rtc_time rtc_tm;
107 unsigned char mon, day, hrs, min, sec, leap_yr;
108 unsigned int yrs;
109
110 if (!capable(CAP_SYS_TIME))
111 return -EACCES;
112
113 if (copy_from_user(&rtc_tm, (struct rtc_time*)arg,
114 sizeof(struct rtc_time)))
115 return -EFAULT;
116
117 yrs = rtc_tm.tm_year;
118 mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
119 day = rtc_tm.tm_mday;
120 hrs = rtc_tm.tm_hour;
121 min = rtc_tm.tm_min;
122 sec = rtc_tm.tm_sec;
123
124 if (yrs < 70)
125 return -EINVAL;
126
127 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
128
129 if ((mon > 12) || (day == 0))
130 return -EINVAL;
131
132 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
133 return -EINVAL;
134
135 if ((hrs >= 24) || (min >= 60) || (sec >= 60))
136 return -EINVAL;
137
138 if ( yrs > 169 )
139 return -EINVAL;
140
141 ppc_md.set_rtc_time(&rtc_tm);
142
143 return 0;
144 }
145 case RTC_EPOCH_READ: /* Read the epoch. */
146 {
147 return put_user (epoch, (unsigned long *)arg);
148 }
149 case RTC_EPOCH_SET: /* Set the epoch. */
150 {
151 /*
152 * There were no RTC clocks before 1900.
153 */
154 if (arg < 1900)
155 return -EINVAL;
156
157 if (!capable(CAP_SYS_TIME))
158 return -EACCES;
159
160 epoch = arg;
161 return 0;
162 }
163 default:
164 return -EINVAL;
165 }
166 return copy_to_user((void *)arg, &wtime, sizeof wtime) ? -EFAULT : 0;
167 }
168
rtc_open(struct inode * inode,struct file * file)169 static int rtc_open(struct inode *inode, struct file *file)
170 {
171 return 0;
172 }
173
rtc_release(struct inode * inode,struct file * file)174 static int rtc_release(struct inode *inode, struct file *file)
175 {
176 return 0;
177 }
178
179 /*
180 * The various file operations we support.
181 */
182 static struct file_operations rtc_fops = {
183 .owner = THIS_MODULE,
184 .llseek = rtc_llseek,
185 .read = rtc_read,
186 .ioctl = rtc_ioctl,
187 .open = rtc_open,
188 .release = rtc_release,
189 };
190
191 static struct miscdevice rtc_dev=
192 {
193 RTC_MINOR,
194 "rtc",
195 &rtc_fops
196 };
197
rtc_init(void)198 static int __init rtc_init(void)
199 {
200 misc_register(&rtc_dev);
201 create_proc_read_entry ("driver/rtc", 0, 0, rtc_read_proc, NULL);
202
203 printk(KERN_INFO "i/pSeries Real Time Clock Driver v" RTC_VERSION "\n");
204
205 return 0;
206 }
207
rtc_exit(void)208 static void __exit rtc_exit (void)
209 {
210 remove_proc_entry ("driver/rtc", NULL);
211 misc_deregister(&rtc_dev);
212 }
213
214 module_init(rtc_init);
215 module_exit(rtc_exit);
216 EXPORT_NO_SYMBOLS;
217
218 /*
219 * Info exported via "/proc/driver/rtc".
220 */
221
rtc_proc_output(char * buf)222 static int rtc_proc_output (char *buf)
223 {
224
225 char *p;
226 struct rtc_time tm;
227
228 p = buf;
229
230 ppc_md.get_rtc_time(&tm);
231
232 /*
233 * There is no way to tell if the luser has the RTC set for local
234 * time or for Universal Standard Time (GMT). Probably local though.
235 */
236 p += sprintf(p,
237 "rtc_time\t: %02d:%02d:%02d\n"
238 "rtc_date\t: %04d-%02d-%02d\n"
239 "rtc_epoch\t: %04lu\n",
240 tm.tm_hour, tm.tm_min, tm.tm_sec,
241 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch);
242
243 p += sprintf(p,
244 "DST_enable\t: no\n"
245 "BCD\t\t: yes\n"
246 "24hr\t\t: yes\n" );
247
248 return p - buf;
249 }
250
rtc_read_proc(char * page,char ** start,off_t off,int count,int * eof,void * data)251 static int rtc_read_proc(char *page, char **start, off_t off,
252 int count, int *eof, void *data)
253 {
254 int len = rtc_proc_output (page);
255 if (len <= off+count) *eof = 1;
256 *start = page + off;
257 len -= off;
258 if (len>count) len = count;
259 if (len<0) len = 0;
260 return len;
261 }
262
263 /*
264 * Get the RTC from the virtual service processor
265 * This requires flowing LpEvents to the primary partition
266 */
iSeries_get_rtc_time(struct rtc_time * rtc_tm)267 void iSeries_get_rtc_time(struct rtc_time *rtc_tm)
268 {
269 if (piranha_simulator)
270 return;
271
272 mf_getRtc(rtc_tm);
273 rtc_tm->tm_mon--;
274 }
275
276
277 #define MAX_RTC_WAIT 5000 /* 5 sec */
278 #define RTAS_CLOCK_BUSY (-2)
pSeries_get_boot_time(struct rtc_time * rtc_tm)279 void pSeries_get_boot_time(struct rtc_time *rtc_tm)
280 {
281 unsigned long ret[8];
282 int error, wait_time;
283 unsigned long max_wait_tb;
284
285 max_wait_tb = __get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
286 do {
287 error = rtas_call(rtas_token("get-time-of-day"), 0, 8, (void *)&ret);
288 if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) {
289 wait_time = rtas_extended_busy_delay_time(error);
290 /* This is boot time so we spin. */
291 udelay(wait_time*1000);
292 error = RTAS_CLOCK_BUSY;
293 }
294 } while (error == RTAS_CLOCK_BUSY && (__get_tb() < max_wait_tb));
295
296 if (error != 0) {
297 printk(KERN_WARNING "error: reading the clock failed (%d)\n",
298 error);
299 return;
300 }
301
302 rtc_tm->tm_sec = ret[5];
303 rtc_tm->tm_min = ret[4];
304 rtc_tm->tm_hour = ret[3];
305 rtc_tm->tm_mday = ret[2];
306 rtc_tm->tm_mon = ret[1] - 1;
307 rtc_tm->tm_year = ret[0] - 1900;
308 }
309
310 /* NOTE: get_rtc_time will get an error if executed in interrupt context
311 * and if a delay is needed to read the clock. In this case we just
312 * silently return without updating rtc_tm.
313 */
pSeries_get_rtc_time(struct rtc_time * rtc_tm)314 void pSeries_get_rtc_time(struct rtc_time *rtc_tm)
315 {
316 unsigned long ret[8];
317 int error, wait_time;
318 unsigned long max_wait_tb;
319
320 max_wait_tb = __get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
321 do {
322 error = rtas_call(rtas_token("get-time-of-day"), 0, 8, (void *)&ret);
323 if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) {
324 if (in_interrupt()) {
325 printk(KERN_WARNING "error: reading clock would delay interrupt\n");
326 return; /* delay not allowed */
327 }
328 wait_time = rtas_extended_busy_delay_time(error);
329 set_current_state(TASK_INTERRUPTIBLE);
330 schedule_timeout(wait_time);
331 error = RTAS_CLOCK_BUSY;
332 }
333 } while (error == RTAS_CLOCK_BUSY && (__get_tb() < max_wait_tb));
334
335 if (error != 0) {
336 printk(KERN_WARNING "error: reading the clock failed (%d)\n",
337 error);
338 return;
339 }
340
341 rtc_tm->tm_sec = ret[5];
342 rtc_tm->tm_min = ret[4];
343 rtc_tm->tm_hour = ret[3];
344 rtc_tm->tm_mday = ret[2];
345 rtc_tm->tm_mon = ret[1] - 1;
346 rtc_tm->tm_year = ret[0] - 1900;
347 }
348
pSeries_set_rtc_time(struct rtc_time * tm)349 int pSeries_set_rtc_time(struct rtc_time *tm)
350 {
351 int error, wait_time;
352 unsigned long max_wait_tb;
353
354 max_wait_tb = __get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
355 do {
356 error = rtas_call(rtas_token("set-time-of-day"), 7, 1, NULL,
357 tm->tm_year + 1900, tm->tm_mon + 1,
358 tm->tm_mday, tm->tm_hour, tm->tm_min,
359 tm->tm_sec, 0);
360 if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) {
361 if (in_interrupt())
362 return 1; /* probably decrementer */
363 wait_time = rtas_extended_busy_delay_time(error);
364 set_current_state(TASK_INTERRUPTIBLE);
365 schedule_timeout(wait_time);
366 error = RTAS_CLOCK_BUSY;
367 }
368 } while (error == RTAS_CLOCK_BUSY && (__get_tb() < max_wait_tb));
369
370 if (error != 0)
371 printk(KERN_WARNING "error: setting the clock failed (%d)\n",
372 error);
373
374 return 0;
375 }
376
377 /*
378 * Set the RTC in the virtual service processor
379 * This requires flowing LpEvents to the primary partition
380 */
iSeries_set_rtc_time(struct rtc_time * tm)381 int iSeries_set_rtc_time(struct rtc_time *tm)
382 {
383 mf_setRtc(tm);
384 return 0;
385 }
386
iSeries_get_boot_time(struct rtc_time * tm)387 void iSeries_get_boot_time(struct rtc_time *tm)
388 {
389 unsigned long time;
390 static unsigned long lastsec = 1;
391
392 u32 dataWord1 = *((u32 *)(&xSpCommArea.xBcdTimeAtIplStart));
393 u32 dataWord2 = *(((u32 *)&(xSpCommArea.xBcdTimeAtIplStart)) + 1);
394 int year = 1970;
395 int year1 = ( dataWord1 >> 24 ) & 0x000000FF;
396 int year2 = ( dataWord1 >> 16 ) & 0x000000FF;
397 int sec = ( dataWord1 >> 8 ) & 0x000000FF;
398 int min = dataWord1 & 0x000000FF;
399 int hour = ( dataWord2 >> 24 ) & 0x000000FF;
400 int day = ( dataWord2 >> 8 ) & 0x000000FF;
401 int mon = dataWord2 & 0x000000FF;
402
403 if ( piranha_simulator )
404 return;
405
406 BCD_TO_BIN(sec);
407 BCD_TO_BIN(min);
408 BCD_TO_BIN(hour);
409 BCD_TO_BIN(day);
410 BCD_TO_BIN(mon);
411 BCD_TO_BIN(year1);
412 BCD_TO_BIN(year2);
413 year = year1 * 100 + year2;
414
415 time = mktime(year, mon, day, hour, min, sec);
416 time += ( jiffies / HZ );
417
418 /* Now THIS is a nasty hack!
419 * It ensures that the first two calls get different answers.
420 * That way the loop in init_time (time.c) will not think
421 * the clock is stuck.
422 */
423 if ( lastsec ) {
424 time -= lastsec;
425 --lastsec;
426 }
427
428 to_tm(time, tm);
429 tm->tm_year -= 1900;
430 tm->tm_mon -= 1;
431 }
432