xref: /openbmc/linux/drivers/input/misc/hp_sdc_rtc.c (revision 9a29ad52)
1 /*
2  * HP i8042 SDC + MSM-58321 BBRTC driver.
3  *
4  * Copyright (c) 2001 Brian S. Julin
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions, and the following disclaimer,
12  *    without modification.
13  * 2. The name of the author may not be used to endorse or promote products
14  *    derived from this software without specific prior written permission.
15  *
16  * Alternatively, this software may be distributed under the terms of the
17  * GNU General Public License ("GPL").
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
23  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  *
29  * References:
30  * System Device Controller Microprocessor Firmware Theory of Operation
31  *      for Part Number 1820-4784 Revision B.  Dwg No. A-1820-4784-2
32  * efirtc.c by Stephane Eranian/Hewlett Packard
33  *
34  */
35 
36 #include <linux/hp_sdc.h>
37 #include <linux/errno.h>
38 #include <linux/types.h>
39 #include <linux/init.h>
40 #include <linux/module.h>
41 #include <linux/time.h>
42 #include <linux/miscdevice.h>
43 #include <linux/proc_fs.h>
44 #include <linux/seq_file.h>
45 #include <linux/poll.h>
46 #include <linux/rtc.h>
47 #include <linux/mutex.h>
48 #include <linux/semaphore.h>
49 
50 MODULE_AUTHOR("Brian S. Julin <bri@calyx.com>");
51 MODULE_DESCRIPTION("HP i8042 SDC + MSM-58321 RTC Driver");
52 MODULE_LICENSE("Dual BSD/GPL");
53 
54 #define RTC_VERSION "1.10d"
55 
56 static DEFINE_MUTEX(hp_sdc_rtc_mutex);
57 static unsigned long epoch = 2000;
58 
59 static struct semaphore i8042tregs;
60 
61 static hp_sdc_irqhook hp_sdc_rtc_isr;
62 
63 static struct fasync_struct *hp_sdc_rtc_async_queue;
64 
65 static DECLARE_WAIT_QUEUE_HEAD(hp_sdc_rtc_wait);
66 
67 static ssize_t hp_sdc_rtc_read(struct file *file, char __user *buf,
68 			       size_t count, loff_t *ppos);
69 
70 static long hp_sdc_rtc_unlocked_ioctl(struct file *file,
71 				      unsigned int cmd, unsigned long arg);
72 
73 static unsigned int hp_sdc_rtc_poll(struct file *file, poll_table *wait);
74 
75 static int hp_sdc_rtc_open(struct inode *inode, struct file *file);
76 static int hp_sdc_rtc_fasync (int fd, struct file *filp, int on);
77 
78 static void hp_sdc_rtc_isr (int irq, void *dev_id,
79 			    uint8_t status, uint8_t data)
80 {
81 	return;
82 }
83 
84 static int hp_sdc_rtc_do_read_bbrtc (struct rtc_time *rtctm)
85 {
86 	struct semaphore tsem;
87 	hp_sdc_transaction t;
88 	uint8_t tseq[91];
89 	int i;
90 
91 	i = 0;
92 	while (i < 91) {
93 		tseq[i++] = HP_SDC_ACT_DATAREG |
94 			HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN;
95 		tseq[i++] = 0x01;			/* write i8042[0x70] */
96 	  	tseq[i]   = i / 7;			/* BBRTC reg address */
97 		i++;
98 		tseq[i++] = HP_SDC_CMD_DO_RTCR;		/* Trigger command   */
99 		tseq[i++] = 2;		/* expect 1 stat/dat pair back.   */
100 		i++; i++;               /* buffer for stat/dat pair       */
101 	}
102 	tseq[84] |= HP_SDC_ACT_SEMAPHORE;
103 	t.endidx =		91;
104 	t.seq =			tseq;
105 	t.act.semaphore =	&tsem;
106 	sema_init(&tsem, 0);
107 
108 	if (hp_sdc_enqueue_transaction(&t)) return -1;
109 
110 	/* Put ourselves to sleep for results. */
111 	if (WARN_ON(down_interruptible(&tsem)))
112 		return -1;
113 
114 	/* Check for nonpresence of BBRTC */
115 	if (!((tseq[83] | tseq[90] | tseq[69] | tseq[76] |
116 	       tseq[55] | tseq[62] | tseq[34] | tseq[41] |
117 	       tseq[20] | tseq[27] | tseq[6]  | tseq[13]) & 0x0f))
118 		return -1;
119 
120 	memset(rtctm, 0, sizeof(struct rtc_time));
121 	rtctm->tm_year = (tseq[83] & 0x0f) + (tseq[90] & 0x0f) * 10;
122 	rtctm->tm_mon  = (tseq[69] & 0x0f) + (tseq[76] & 0x0f) * 10;
123 	rtctm->tm_mday = (tseq[55] & 0x0f) + (tseq[62] & 0x0f) * 10;
124 	rtctm->tm_wday = (tseq[48] & 0x0f);
125 	rtctm->tm_hour = (tseq[34] & 0x0f) + (tseq[41] & 0x0f) * 10;
126 	rtctm->tm_min  = (tseq[20] & 0x0f) + (tseq[27] & 0x0f) * 10;
127 	rtctm->tm_sec  = (tseq[6]  & 0x0f) + (tseq[13] & 0x0f) * 10;
128 
129 	return 0;
130 }
131 
132 static int hp_sdc_rtc_read_bbrtc (struct rtc_time *rtctm)
133 {
134 	struct rtc_time tm, tm_last;
135 	int i = 0;
136 
137 	/* MSM-58321 has no read latch, so must read twice and compare. */
138 
139 	if (hp_sdc_rtc_do_read_bbrtc(&tm_last)) return -1;
140 	if (hp_sdc_rtc_do_read_bbrtc(&tm)) return -1;
141 
142 	while (memcmp(&tm, &tm_last, sizeof(struct rtc_time))) {
143 		if (i++ > 4) return -1;
144 		memcpy(&tm_last, &tm, sizeof(struct rtc_time));
145 		if (hp_sdc_rtc_do_read_bbrtc(&tm)) return -1;
146 	}
147 
148 	memcpy(rtctm, &tm, sizeof(struct rtc_time));
149 
150 	return 0;
151 }
152 
153 
154 static int64_t hp_sdc_rtc_read_i8042timer (uint8_t loadcmd, int numreg)
155 {
156 	hp_sdc_transaction t;
157 	uint8_t tseq[26] = {
158 		HP_SDC_ACT_PRECMD | HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN,
159 		0,
160 		HP_SDC_CMD_READ_T1, 2, 0, 0,
161 		HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN,
162 		HP_SDC_CMD_READ_T2, 2, 0, 0,
163 		HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN,
164 		HP_SDC_CMD_READ_T3, 2, 0, 0,
165 		HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN,
166 		HP_SDC_CMD_READ_T4, 2, 0, 0,
167 		HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN,
168 		HP_SDC_CMD_READ_T5, 2, 0, 0
169 	};
170 
171 	t.endidx = numreg * 5;
172 
173 	tseq[1] = loadcmd;
174 	tseq[t.endidx - 4] |= HP_SDC_ACT_SEMAPHORE; /* numreg assumed > 1 */
175 
176 	t.seq =			tseq;
177 	t.act.semaphore =	&i8042tregs;
178 
179 	/* Sleep if output regs in use. */
180 	if (WARN_ON(down_interruptible(&i8042tregs)))
181 		return -1;
182 
183 	if (hp_sdc_enqueue_transaction(&t)) {
184 		up(&i8042tregs);
185 		return -1;
186 	}
187 
188 	/* Sleep until results come back. */
189 	if (WARN_ON(down_interruptible(&i8042tregs)))
190 		return -1;
191 
192 	up(&i8042tregs);
193 
194 	return (tseq[5] |
195 		((uint64_t)(tseq[10]) << 8)  | ((uint64_t)(tseq[15]) << 16) |
196 		((uint64_t)(tseq[20]) << 24) | ((uint64_t)(tseq[25]) << 32));
197 }
198 
199 
200 /* Read the i8042 real-time clock */
201 static inline int hp_sdc_rtc_read_rt(struct timespec64 *res) {
202 	int64_t raw;
203 	uint32_t tenms;
204 	unsigned int days;
205 
206 	raw = hp_sdc_rtc_read_i8042timer(HP_SDC_CMD_LOAD_RT, 5);
207 	if (raw < 0) return -1;
208 
209 	tenms = (uint32_t)raw & 0xffffff;
210 	days  = (unsigned int)(raw >> 24) & 0xffff;
211 
212 	res->tv_nsec = (long)(tenms % 100) * 10000 * 1000;
213 	res->tv_sec =  (tenms / 100) + (time64_t)days * 86400;
214 
215 	return 0;
216 }
217 
218 
219 /* Read the i8042 fast handshake timer */
220 static inline int hp_sdc_rtc_read_fhs(struct timespec64 *res) {
221 	int64_t raw;
222 	unsigned int tenms;
223 
224 	raw = hp_sdc_rtc_read_i8042timer(HP_SDC_CMD_LOAD_FHS, 2);
225 	if (raw < 0) return -1;
226 
227 	tenms = (unsigned int)raw & 0xffff;
228 
229 	res->tv_nsec = (long)(tenms % 100) * 10000 * 1000;
230 	res->tv_sec  = (time64_t)(tenms / 100);
231 
232 	return 0;
233 }
234 
235 
236 /* Read the i8042 match timer (a.k.a. alarm) */
237 static inline int hp_sdc_rtc_read_mt(struct timespec64 *res) {
238 	int64_t raw;
239 	uint32_t tenms;
240 
241 	raw = hp_sdc_rtc_read_i8042timer(HP_SDC_CMD_LOAD_MT, 3);
242 	if (raw < 0) return -1;
243 
244 	tenms = (uint32_t)raw & 0xffffff;
245 
246 	res->tv_nsec = (long)(tenms % 100) * 10000 * 1000;
247 	res->tv_sec  = (time64_t)(tenms / 100);
248 
249 	return 0;
250 }
251 
252 
253 /* Read the i8042 delay timer */
254 static inline int hp_sdc_rtc_read_dt(struct timespec64 *res) {
255 	int64_t raw;
256 	uint32_t tenms;
257 
258 	raw = hp_sdc_rtc_read_i8042timer(HP_SDC_CMD_LOAD_DT, 3);
259 	if (raw < 0) return -1;
260 
261 	tenms = (uint32_t)raw & 0xffffff;
262 
263 	res->tv_nsec = (long)(tenms % 100) * 10000 * 1000;
264 	res->tv_sec  = (time64_t)(tenms / 100);
265 
266 	return 0;
267 }
268 
269 
270 /* Read the i8042 cycle timer (a.k.a. periodic) */
271 static inline int hp_sdc_rtc_read_ct(struct timespec64 *res) {
272 	int64_t raw;
273 	uint32_t tenms;
274 
275 	raw = hp_sdc_rtc_read_i8042timer(HP_SDC_CMD_LOAD_CT, 3);
276 	if (raw < 0) return -1;
277 
278 	tenms = (uint32_t)raw & 0xffffff;
279 
280 	res->tv_nsec = (long)(tenms % 100) * 10000 * 1000;
281 	res->tv_sec  = (time64_t)(tenms / 100);
282 
283 	return 0;
284 }
285 
286 
287 #if 0 /* not used yet */
288 /* Set the i8042 real-time clock */
289 static int hp_sdc_rtc_set_rt (struct timeval *setto)
290 {
291 	uint32_t tenms;
292 	unsigned int days;
293 	hp_sdc_transaction t;
294 	uint8_t tseq[11] = {
295 		HP_SDC_ACT_PRECMD | HP_SDC_ACT_DATAOUT,
296 		HP_SDC_CMD_SET_RTMS, 3, 0, 0, 0,
297 		HP_SDC_ACT_PRECMD | HP_SDC_ACT_DATAOUT,
298 		HP_SDC_CMD_SET_RTD, 2, 0, 0
299 	};
300 
301 	t.endidx = 10;
302 
303 	if (0xffff < setto->tv_sec / 86400) return -1;
304 	days = setto->tv_sec / 86400;
305 	if (0xffff < setto->tv_usec / 1000000 / 86400) return -1;
306 	days += ((setto->tv_sec % 86400) + setto->tv_usec / 1000000) / 86400;
307 	if (days > 0xffff) return -1;
308 
309 	if (0xffffff < setto->tv_sec) return -1;
310 	tenms  = setto->tv_sec * 100;
311 	if (0xffffff < setto->tv_usec / 10000) return -1;
312 	tenms += setto->tv_usec / 10000;
313 	if (tenms > 0xffffff) return -1;
314 
315 	tseq[3] = (uint8_t)(tenms & 0xff);
316 	tseq[4] = (uint8_t)((tenms >> 8)  & 0xff);
317 	tseq[5] = (uint8_t)((tenms >> 16) & 0xff);
318 
319 	tseq[9] = (uint8_t)(days & 0xff);
320 	tseq[10] = (uint8_t)((days >> 8) & 0xff);
321 
322 	t.seq =	tseq;
323 
324 	if (hp_sdc_enqueue_transaction(&t)) return -1;
325 	return 0;
326 }
327 
328 /* Set the i8042 fast handshake timer */
329 static int hp_sdc_rtc_set_fhs (struct timeval *setto)
330 {
331 	uint32_t tenms;
332 	hp_sdc_transaction t;
333 	uint8_t tseq[5] = {
334 		HP_SDC_ACT_PRECMD | HP_SDC_ACT_DATAOUT,
335 		HP_SDC_CMD_SET_FHS, 2, 0, 0
336 	};
337 
338 	t.endidx = 4;
339 
340 	if (0xffff < setto->tv_sec) return -1;
341 	tenms  = setto->tv_sec * 100;
342 	if (0xffff < setto->tv_usec / 10000) return -1;
343 	tenms += setto->tv_usec / 10000;
344 	if (tenms > 0xffff) return -1;
345 
346 	tseq[3] = (uint8_t)(tenms & 0xff);
347 	tseq[4] = (uint8_t)((tenms >> 8)  & 0xff);
348 
349 	t.seq =	tseq;
350 
351 	if (hp_sdc_enqueue_transaction(&t)) return -1;
352 	return 0;
353 }
354 
355 
356 /* Set the i8042 match timer (a.k.a. alarm) */
357 #define hp_sdc_rtc_set_mt (setto) \
358 	hp_sdc_rtc_set_i8042timer(setto, HP_SDC_CMD_SET_MT)
359 
360 /* Set the i8042 delay timer */
361 #define hp_sdc_rtc_set_dt (setto) \
362 	hp_sdc_rtc_set_i8042timer(setto, HP_SDC_CMD_SET_DT)
363 
364 /* Set the i8042 cycle timer (a.k.a. periodic) */
365 #define hp_sdc_rtc_set_ct (setto) \
366 	hp_sdc_rtc_set_i8042timer(setto, HP_SDC_CMD_SET_CT)
367 
368 /* Set one of the i8042 3-byte wide timers */
369 static int hp_sdc_rtc_set_i8042timer (struct timeval *setto, uint8_t setcmd)
370 {
371 	uint32_t tenms;
372 	hp_sdc_transaction t;
373 	uint8_t tseq[6] = {
374 		HP_SDC_ACT_PRECMD | HP_SDC_ACT_DATAOUT,
375 		0, 3, 0, 0, 0
376 	};
377 
378 	t.endidx = 6;
379 
380 	if (0xffffff < setto->tv_sec) return -1;
381 	tenms  = setto->tv_sec * 100;
382 	if (0xffffff < setto->tv_usec / 10000) return -1;
383 	tenms += setto->tv_usec / 10000;
384 	if (tenms > 0xffffff) return -1;
385 
386 	tseq[1] = setcmd;
387 	tseq[3] = (uint8_t)(tenms & 0xff);
388 	tseq[4] = (uint8_t)((tenms >> 8)  & 0xff);
389 	tseq[5] = (uint8_t)((tenms >> 16)  & 0xff);
390 
391 	t.seq =			tseq;
392 
393 	if (hp_sdc_enqueue_transaction(&t)) {
394 		return -1;
395 	}
396 	return 0;
397 }
398 #endif
399 
400 static ssize_t hp_sdc_rtc_read(struct file *file, char __user *buf,
401 			       size_t count, loff_t *ppos) {
402 	ssize_t retval;
403 
404         if (count < sizeof(unsigned long))
405                 return -EINVAL;
406 
407 	retval = put_user(68, (unsigned long __user *)buf);
408 	return retval;
409 }
410 
411 static __poll_t hp_sdc_rtc_poll(struct file *file, poll_table *wait)
412 {
413         unsigned long l;
414 
415 	l = 0;
416         if (l != 0)
417                 return EPOLLIN | EPOLLRDNORM;
418         return 0;
419 }
420 
421 static int hp_sdc_rtc_open(struct inode *inode, struct file *file)
422 {
423         return 0;
424 }
425 
426 static int hp_sdc_rtc_fasync (int fd, struct file *filp, int on)
427 {
428         return fasync_helper (fd, filp, on, &hp_sdc_rtc_async_queue);
429 }
430 
431 static int hp_sdc_rtc_proc_show(struct seq_file *m, void *v)
432 {
433 #define YN(bit) ("no")
434 #define NY(bit) ("yes")
435         struct rtc_time tm;
436 	struct timespec64 tv;
437 
438 	memset(&tm, 0, sizeof(struct rtc_time));
439 
440 	if (hp_sdc_rtc_read_bbrtc(&tm)) {
441 		seq_puts(m, "BBRTC\t\t: READ FAILED!\n");
442 	} else {
443 		seq_printf(m,
444 			     "rtc_time\t: %02d:%02d:%02d\n"
445 			     "rtc_date\t: %04d-%02d-%02d\n"
446 			     "rtc_epoch\t: %04lu\n",
447 			     tm.tm_hour, tm.tm_min, tm.tm_sec,
448 			     tm.tm_year + 1900, tm.tm_mon + 1,
449 			     tm.tm_mday, epoch);
450 	}
451 
452 	if (hp_sdc_rtc_read_rt(&tv)) {
453 		seq_puts(m, "i8042 rtc\t: READ FAILED!\n");
454 	} else {
455 		seq_printf(m, "i8042 rtc\t: %lld.%02ld seconds\n",
456 			     (s64)tv.tv_sec, (long)tv.tv_nsec/1000000L);
457 	}
458 
459 	if (hp_sdc_rtc_read_fhs(&tv)) {
460 		seq_puts(m, "handshake\t: READ FAILED!\n");
461 	} else {
462 		seq_printf(m, "handshake\t: %lld.%02ld seconds\n",
463 			     (s64)tv.tv_sec, (long)tv.tv_nsec/1000000L);
464 	}
465 
466 	if (hp_sdc_rtc_read_mt(&tv)) {
467 		seq_puts(m, "alarm\t\t: READ FAILED!\n");
468 	} else {
469 		seq_printf(m, "alarm\t\t: %lld.%02ld seconds\n",
470 			     (s64)tv.tv_sec, (long)tv.tv_nsec/1000000L);
471 	}
472 
473 	if (hp_sdc_rtc_read_dt(&tv)) {
474 		seq_puts(m, "delay\t\t: READ FAILED!\n");
475 	} else {
476 		seq_printf(m, "delay\t\t: %lld.%02ld seconds\n",
477 			     (s64)tv.tv_sec, (long)tv.tv_nsec/1000000L);
478 	}
479 
480 	if (hp_sdc_rtc_read_ct(&tv)) {
481 		seq_puts(m, "periodic\t: READ FAILED!\n");
482 	} else {
483 		seq_printf(m, "periodic\t: %lld.%02ld seconds\n",
484 			     (s64)tv.tv_sec, (long)tv.tv_nsec/1000000L);
485 	}
486 
487         seq_printf(m,
488                      "DST_enable\t: %s\n"
489                      "BCD\t\t: %s\n"
490                      "24hr\t\t: %s\n"
491                      "square_wave\t: %s\n"
492                      "alarm_IRQ\t: %s\n"
493                      "update_IRQ\t: %s\n"
494                      "periodic_IRQ\t: %s\n"
495 		     "periodic_freq\t: %ld\n"
496                      "batt_status\t: %s\n",
497                      YN(RTC_DST_EN),
498                      NY(RTC_DM_BINARY),
499                      YN(RTC_24H),
500                      YN(RTC_SQWE),
501                      YN(RTC_AIE),
502                      YN(RTC_UIE),
503                      YN(RTC_PIE),
504                      1UL,
505                      1 ? "okay" : "dead");
506 
507         return 0;
508 #undef YN
509 #undef NY
510 }
511 
512 static int hp_sdc_rtc_ioctl(struct file *file,
513 			    unsigned int cmd, unsigned long arg)
514 {
515 #if 1
516 	return -EINVAL;
517 #else
518 
519         struct rtc_time wtime;
520 	struct timeval ttime;
521 	int use_wtime = 0;
522 
523 	/* This needs major work. */
524 
525         switch (cmd) {
526 
527         case RTC_AIE_OFF:       /* Mask alarm int. enab. bit    */
528         case RTC_AIE_ON:        /* Allow alarm interrupts.      */
529 	case RTC_PIE_OFF:       /* Mask periodic int. enab. bit */
530         case RTC_PIE_ON:        /* Allow periodic ints          */
531         case RTC_UIE_ON:        /* Allow ints for RTC updates.  */
532         case RTC_UIE_OFF:       /* Allow ints for RTC updates.  */
533         {
534 		/* We cannot mask individual user timers and we
535 		   cannot tell them apart when they occur, so it
536 		   would be disingenuous to succeed these IOCTLs */
537 		return -EINVAL;
538         }
539         case RTC_ALM_READ:      /* Read the present alarm time */
540         {
541 		if (hp_sdc_rtc_read_mt(&ttime)) return -EFAULT;
542 		if (hp_sdc_rtc_read_bbrtc(&wtime)) return -EFAULT;
543 
544 		wtime.tm_hour = ttime.tv_sec / 3600;  ttime.tv_sec %= 3600;
545 		wtime.tm_min  = ttime.tv_sec / 60;    ttime.tv_sec %= 60;
546 		wtime.tm_sec  = ttime.tv_sec;
547 
548 		break;
549         }
550         case RTC_IRQP_READ:     /* Read the periodic IRQ rate.  */
551         {
552                 return put_user(hp_sdc_rtc_freq, (unsigned long *)arg);
553         }
554         case RTC_IRQP_SET:      /* Set periodic IRQ rate.       */
555         {
556                 /*
557                  * The max we can do is 100Hz.
558 		 */
559 
560                 if ((arg < 1) || (arg > 100)) return -EINVAL;
561 		ttime.tv_sec = 0;
562 		ttime.tv_usec = 1000000 / arg;
563 		if (hp_sdc_rtc_set_ct(&ttime)) return -EFAULT;
564 		hp_sdc_rtc_freq = arg;
565                 return 0;
566         }
567         case RTC_ALM_SET:       /* Store a time into the alarm */
568         {
569                 /*
570                  * This expects a struct hp_sdc_rtc_time. Writing 0xff means
571                  * "don't care" or "match all" for PC timers.  The HP SDC
572 		 * does not support that perk, but it could be emulated fairly
573 		 * easily.  Only the tm_hour, tm_min and tm_sec are used.
574 		 * We could do it with 10ms accuracy with the HP SDC, if the
575 		 * rtc interface left us a way to do that.
576                  */
577                 struct hp_sdc_rtc_time alm_tm;
578 
579                 if (copy_from_user(&alm_tm, (struct hp_sdc_rtc_time*)arg,
580                                    sizeof(struct hp_sdc_rtc_time)))
581                        return -EFAULT;
582 
583                 if (alm_tm.tm_hour > 23) return -EINVAL;
584 		if (alm_tm.tm_min  > 59) return -EINVAL;
585 		if (alm_tm.tm_sec  > 59) return -EINVAL;
586 
587 		ttime.sec = alm_tm.tm_hour * 3600 +
588 		  alm_tm.tm_min * 60 + alm_tm.tm_sec;
589 		ttime.usec = 0;
590 		if (hp_sdc_rtc_set_mt(&ttime)) return -EFAULT;
591                 return 0;
592         }
593         case RTC_RD_TIME:       /* Read the time/date from RTC  */
594         {
595 		if (hp_sdc_rtc_read_bbrtc(&wtime)) return -EFAULT;
596                 break;
597         }
598         case RTC_SET_TIME:      /* Set the RTC */
599         {
600                 struct rtc_time hp_sdc_rtc_tm;
601                 unsigned char mon, day, hrs, min, sec, leap_yr;
602                 unsigned int yrs;
603 
604                 if (!capable(CAP_SYS_TIME))
605                         return -EACCES;
606 		if (copy_from_user(&hp_sdc_rtc_tm, (struct rtc_time *)arg,
607                                    sizeof(struct rtc_time)))
608                         return -EFAULT;
609 
610                 yrs = hp_sdc_rtc_tm.tm_year + 1900;
611                 mon = hp_sdc_rtc_tm.tm_mon + 1;   /* tm_mon starts at zero */
612                 day = hp_sdc_rtc_tm.tm_mday;
613                 hrs = hp_sdc_rtc_tm.tm_hour;
614                 min = hp_sdc_rtc_tm.tm_min;
615                 sec = hp_sdc_rtc_tm.tm_sec;
616 
617                 if (yrs < 1970)
618                         return -EINVAL;
619 
620                 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
621 
622                 if ((mon > 12) || (day == 0))
623                         return -EINVAL;
624                 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
625                         return -EINVAL;
626 		if ((hrs >= 24) || (min >= 60) || (sec >= 60))
627                         return -EINVAL;
628 
629                 if ((yrs -= eH) > 255)    /* They are unsigned */
630                         return -EINVAL;
631 
632 
633                 return 0;
634         }
635         case RTC_EPOCH_READ:    /* Read the epoch.      */
636         {
637                 return put_user (epoch, (unsigned long *)arg);
638         }
639         case RTC_EPOCH_SET:     /* Set the epoch.       */
640         {
641                 /*
642                  * There were no RTC clocks before 1900.
643                  */
644                 if (arg < 1900)
645 		  return -EINVAL;
646 		if (!capable(CAP_SYS_TIME))
647 		  return -EACCES;
648 
649                 epoch = arg;
650                 return 0;
651         }
652         default:
653                 return -EINVAL;
654         }
655         return copy_to_user((void *)arg, &wtime, sizeof wtime) ? -EFAULT : 0;
656 #endif
657 }
658 
659 static long hp_sdc_rtc_unlocked_ioctl(struct file *file,
660 				      unsigned int cmd, unsigned long arg)
661 {
662 	int ret;
663 
664 	mutex_lock(&hp_sdc_rtc_mutex);
665 	ret = hp_sdc_rtc_ioctl(file, cmd, arg);
666 	mutex_unlock(&hp_sdc_rtc_mutex);
667 
668 	return ret;
669 }
670 
671 
672 static const struct file_operations hp_sdc_rtc_fops = {
673         .owner =		THIS_MODULE,
674         .llseek =		no_llseek,
675         .read =			hp_sdc_rtc_read,
676         .poll =			hp_sdc_rtc_poll,
677         .unlocked_ioctl =	hp_sdc_rtc_unlocked_ioctl,
678         .open =			hp_sdc_rtc_open,
679         .fasync =		hp_sdc_rtc_fasync,
680 };
681 
682 static struct miscdevice hp_sdc_rtc_dev = {
683         .minor =	RTC_MINOR,
684         .name =		"rtc_HIL",
685         .fops =		&hp_sdc_rtc_fops
686 };
687 
688 static int __init hp_sdc_rtc_init(void)
689 {
690 	int ret;
691 
692 #ifdef __mc68000__
693 	if (!MACH_IS_HP300)
694 		return -ENODEV;
695 #endif
696 
697 	sema_init(&i8042tregs, 1);
698 
699 	if ((ret = hp_sdc_request_timer_irq(&hp_sdc_rtc_isr)))
700 		return ret;
701 	if (misc_register(&hp_sdc_rtc_dev) != 0)
702 		printk(KERN_INFO "Could not register misc. dev for i8042 rtc\n");
703 
704         proc_create_single("driver/rtc", 0, NULL, hp_sdc_rtc_proc_show);
705 
706 	printk(KERN_INFO "HP i8042 SDC + MSM-58321 RTC support loaded "
707 			 "(RTC v " RTC_VERSION ")\n");
708 
709 	return 0;
710 }
711 
712 static void __exit hp_sdc_rtc_exit(void)
713 {
714 	remove_proc_entry ("driver/rtc", NULL);
715         misc_deregister(&hp_sdc_rtc_dev);
716 	hp_sdc_release_timer_irq(hp_sdc_rtc_isr);
717         printk(KERN_INFO "HP i8042 SDC + MSM-58321 RTC support unloaded\n");
718 }
719 
720 module_init(hp_sdc_rtc_init);
721 module_exit(hp_sdc_rtc_exit);
722