aboutsummaryrefslogtreecommitdiffstats
path: root/arch/cris/arch-v10/drivers/ds1302.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/cris/arch-v10/drivers/ds1302.c')
-rw-r--r--arch/cris/arch-v10/drivers/ds1302.c602
1 files changed, 602 insertions, 0 deletions
diff --git a/arch/cris/arch-v10/drivers/ds1302.c b/arch/cris/arch-v10/drivers/ds1302.c
new file mode 100644
index 000000000000..fba530fcfaeb
--- /dev/null
+++ b/arch/cris/arch-v10/drivers/ds1302.c
@@ -0,0 +1,602 @@
1/*!***************************************************************************
2*!
3*! FILE NAME : ds1302.c
4*!
5*! DESCRIPTION: Implements an interface for the DS1302 RTC through Etrax I/O
6*!
7*! Functions exported: ds1302_readreg, ds1302_writereg, ds1302_init
8*!
9*! $Log: ds1302.c,v $
10*! Revision 1.14 2004/08/24 06:48:43 starvik
11*! Whitespace cleanup
12*!
13*! Revision 1.13 2004/05/28 09:26:59 starvik
14*! Modified I2C initialization to work in 2.6.
15*!
16*! Revision 1.12 2004/05/14 07:58:03 starvik
17*! Merge of changes from 2.4
18*!
19*! Revision 1.10 2004/02/04 09:25:12 starvik
20*! Merge of Linux 2.6.2
21*!
22*! Revision 1.9 2003/07/04 08:27:37 starvik
23*! Merge of Linux 2.5.74
24*!
25*! Revision 1.8 2003/04/09 05:20:47 starvik
26*! Merge of Linux 2.5.67
27*!
28*! Revision 1.6 2003/01/09 14:42:51 starvik
29*! Merge of Linux 2.5.55
30*!
31*! Revision 1.4 2002/12/11 13:13:57 starvik
32*! Added arch/ to v10 specific includes
33*! Added fix from Linux 2.4 in serial.c (flush_to_flip_buffer)
34*!
35*! Revision 1.3 2002/11/20 11:56:10 starvik
36*! Merge of Linux 2.5.48
37*!
38*! Revision 1.2 2002/11/18 13:16:06 starvik
39*! Linux 2.5 port of latest 2.4 drivers
40*!
41*! Revision 1.15 2002/10/11 16:14:33 johana
42*! Added CONFIG_ETRAX_DS1302_TRICKLE_CHARGE and initial setting of the
43*! trcklecharge register.
44*!
45*! Revision 1.14 2002/10/10 12:15:38 magnusmn
46*! Added support for having the RST signal on bit g0
47*!
48*! Revision 1.13 2002/05/29 15:16:08 johana
49*! Removed unused variables.
50*!
51*! Revision 1.12 2002/04/10 15:35:25 johana
52*! Moved probe function closer to init function and marked it __init.
53*!
54*! Revision 1.11 2001/06/14 12:35:52 jonashg
55*! The ATA hack is back. It is unfortunately the only way to set g27 to output.
56*!
57*! Revision 1.9 2001/06/14 10:00:14 jonashg
58*! No need for tempudelay to be inline anymore (had to adjust the usec to
59*! loops conversion because of this to make it slow enough to be a udelay).
60*!
61*! Revision 1.8 2001/06/14 08:06:32 jonashg
62*! Made tempudelay delay usecs (well, just a tad more).
63*!
64*! Revision 1.7 2001/06/13 14:18:11 jonashg
65*! Only allow processes with SYS_TIME capability to set time and charge.
66*!
67*! Revision 1.6 2001/06/12 15:22:07 jonashg
68*! * Made init function __init.
69*! * Parameter to out_byte() is unsigned char.
70*! * The magic number 42 has got a name.
71*! * Removed comment about /proc (nothing is exported there).
72*!
73*! Revision 1.5 2001/06/12 14:35:13 jonashg
74*! Gave the module a name and added it to printk's.
75*!
76*! Revision 1.4 2001/05/31 14:53:40 jonashg
77*! Made tempudelay() inline so that the watchdog doesn't reset (see
78*! function comment).
79*!
80*! Revision 1.3 2001/03/26 16:03:06 bjornw
81*! Needs linux/config.h
82*!
83*! Revision 1.2 2001/03/20 19:42:00 bjornw
84*! Use the ETRAX prefix on the DS1302 options
85*!
86*! Revision 1.1 2001/03/20 09:13:50 magnusmn
87*! Linux 2.4 port
88*!
89*! Revision 1.10 2000/07/05 15:38:23 bjornw
90*! Dont update kernel time when a RTC_SET_TIME is done
91*!
92*! Revision 1.9 2000/03/02 15:42:59 macce
93*! * Hack to make RTC work on all 2100/2400
94*!
95*! Revision 1.8 2000/02/23 16:59:18 torbjore
96*! added setup of R_GEN_CONFIG when RTC is connected to the generic port.
97*!
98*! Revision 1.7 2000/01/17 15:51:43 johana
99*! Added RTC_SET_CHARGE ioctl to enable trickle charger.
100*!
101*! Revision 1.6 1999/10/27 13:19:47 bjornw
102*! Added update_xtime_from_cmos which reads back the updated RTC into the kernel.
103*! /dev/rtc calls it now.
104*!
105*! Revision 1.5 1999/10/27 12:39:37 bjornw
106*! Disabled superuser check. Anyone can now set the time.
107*!
108*! Revision 1.4 1999/09/02 13:27:46 pkj
109*! Added shadow for R_PORT_PB_CONFIG.
110*! Renamed port_g_shadow to port_g_data_shadow.
111*!
112*! Revision 1.3 1999/09/02 08:28:06 pkj
113*! Made it possible to select either port PB or the generic port for the RST
114*! signal line to the DS1302 RTC.
115*! Also make sure the RST bit is configured as output on Port PB (if used).
116*!
117*! Revision 1.2 1999/09/01 14:47:20 bjornw
118*! Added support for /dev/rtc operations with ioctl RD_TIME and SET_TIME to read
119*! and set the date. Register as major 121.
120*!
121*! Revision 1.1 1999/09/01 09:45:29 bjornw
122*! Implemented a DS1302 RTC driver.
123*!
124*!
125*! ---------------------------------------------------------------------------
126*!
127*! (C) Copyright 1999, 2000, 2001 Axis Communications AB, LUND, SWEDEN
128*!
129*! $Id: ds1302.c,v 1.14 2004/08/24 06:48:43 starvik Exp $
130*!
131*!***************************************************************************/
132
133#include <linux/config.h>
134
135#include <linux/fs.h>
136#include <linux/init.h>
137#include <linux/mm.h>
138#include <linux/module.h>
139#include <linux/miscdevice.h>
140#include <linux/delay.h>
141#include <linux/bcd.h>
142
143#include <asm/uaccess.h>
144#include <asm/system.h>
145#include <asm/arch/svinto.h>
146#include <asm/io.h>
147#include <asm/rtc.h>
148
149#define RTC_MAJOR_NR 121 /* local major, change later */
150
151static const char ds1302_name[] = "ds1302";
152
153/* The DS1302 might be connected to different bits on different products.
154 * It has three signals - SDA, SCL and RST. RST and SCL are always outputs,
155 * but SDA can have a selected direction.
156 * For now, only PORT_PB is hardcoded.
157 */
158
159/* The RST bit may be on either the Generic Port or Port PB. */
160#ifdef CONFIG_ETRAX_DS1302_RST_ON_GENERIC_PORT
161#define TK_RST_OUT(x) REG_SHADOW_SET(R_PORT_G_DATA, port_g_data_shadow, CONFIG_ETRAX_DS1302_RSTBIT, x)
162#define TK_RST_DIR(x)
163#else
164#define TK_RST_OUT(x) REG_SHADOW_SET(R_PORT_PB_DATA, port_pb_data_shadow, CONFIG_ETRAX_DS1302_RSTBIT, x)
165#define TK_RST_DIR(x) REG_SHADOW_SET(R_PORT_PB_DIR, port_pb_dir_shadow, CONFIG_ETRAX_DS1302_RSTBIT, x)
166#endif
167
168
169#define TK_SDA_OUT(x) REG_SHADOW_SET(R_PORT_PB_DATA, port_pb_data_shadow, CONFIG_ETRAX_DS1302_SDABIT, x)
170#define TK_SCL_OUT(x) REG_SHADOW_SET(R_PORT_PB_DATA, port_pb_data_shadow, CONFIG_ETRAX_DS1302_SCLBIT, x)
171
172#define TK_SDA_IN() ((*R_PORT_PB_READ >> CONFIG_ETRAX_DS1302_SDABIT) & 1)
173/* 1 is out, 0 is in */
174#define TK_SDA_DIR(x) REG_SHADOW_SET(R_PORT_PB_DIR, port_pb_dir_shadow, CONFIG_ETRAX_DS1302_SDABIT, x)
175#define TK_SCL_DIR(x) REG_SHADOW_SET(R_PORT_PB_DIR, port_pb_dir_shadow, CONFIG_ETRAX_DS1302_SCLBIT, x)
176
177
178/*
179 * The reason for tempudelay and not udelay is that loops_per_usec
180 * (used in udelay) is not set when functions here are called from time.c
181 */
182
183static void tempudelay(int usecs)
184{
185 volatile int loops;
186
187 for(loops = usecs * 12; loops > 0; loops--)
188 /* nothing */;
189}
190
191
192/* Send 8 bits. */
193static void
194out_byte(unsigned char x)
195{
196 int i;
197 TK_SDA_DIR(1);
198 for (i = 8; i--;) {
199 /* The chip latches incoming bits on the rising edge of SCL. */
200 TK_SCL_OUT(0);
201 TK_SDA_OUT(x & 1);
202 tempudelay(1);
203 TK_SCL_OUT(1);
204 tempudelay(1);
205 x >>= 1;
206 }
207 TK_SDA_DIR(0);
208}
209
210static unsigned char
211in_byte(void)
212{
213 unsigned char x = 0;
214 int i;
215
216 /* Read byte. Bits come LSB first, on the falling edge of SCL.
217 * Assume SDA is in input direction already.
218 */
219 TK_SDA_DIR(0);
220
221 for (i = 8; i--;) {
222 TK_SCL_OUT(0);
223 tempudelay(1);
224 x >>= 1;
225 x |= (TK_SDA_IN() << 7);
226 TK_SCL_OUT(1);
227 tempudelay(1);
228 }
229
230 return x;
231}
232
233/* Prepares for a transaction by de-activating RST (active-low). */
234
235static void
236start(void)
237{
238 TK_SCL_OUT(0);
239 tempudelay(1);
240 TK_RST_OUT(0);
241 tempudelay(5);
242 TK_RST_OUT(1);
243}
244
245/* Ends a transaction by taking RST active again. */
246
247static void
248stop(void)
249{
250 tempudelay(2);
251 TK_RST_OUT(0);
252}
253
254/* Enable writing. */
255
256static void
257ds1302_wenable(void)
258{
259 start();
260 out_byte(0x8e); /* Write control register */
261 out_byte(0x00); /* Disable write protect bit 7 = 0 */
262 stop();
263}
264
265/* Disable writing. */
266
267static void
268ds1302_wdisable(void)
269{
270 start();
271 out_byte(0x8e); /* Write control register */
272 out_byte(0x80); /* Disable write protect bit 7 = 0 */
273 stop();
274}
275
276
277
278/* Read a byte from the selected register in the DS1302. */
279
280unsigned char
281ds1302_readreg(int reg)
282{
283 unsigned char x;
284
285 start();
286 out_byte(0x81 | (reg << 1)); /* read register */
287 x = in_byte();
288 stop();
289
290 return x;
291}
292
293/* Write a byte to the selected register. */
294
295void
296ds1302_writereg(int reg, unsigned char val)
297{
298#ifndef CONFIG_ETRAX_RTC_READONLY
299 int do_writereg = 1;
300#else
301 int do_writereg = 0;
302
303 if (reg == RTC_TRICKLECHARGER)
304 do_writereg = 1;
305#endif
306
307 if (do_writereg) {
308 ds1302_wenable();
309 start();
310 out_byte(0x80 | (reg << 1)); /* write register */
311 out_byte(val);
312 stop();
313 ds1302_wdisable();
314 }
315}
316
317void
318get_rtc_time(struct rtc_time *rtc_tm)
319{
320 unsigned long flags;
321
322 local_irq_save(flags);
323 local_irq_disable();
324
325 rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);
326 rtc_tm->tm_min = CMOS_READ(RTC_MINUTES);
327 rtc_tm->tm_hour = CMOS_READ(RTC_HOURS);
328 rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
329 rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);
330 rtc_tm->tm_year = CMOS_READ(RTC_YEAR);
331
332 local_irq_restore(flags);
333
334 BCD_TO_BIN(rtc_tm->tm_sec);
335 BCD_TO_BIN(rtc_tm->tm_min);
336 BCD_TO_BIN(rtc_tm->tm_hour);
337 BCD_TO_BIN(rtc_tm->tm_mday);
338 BCD_TO_BIN(rtc_tm->tm_mon);
339 BCD_TO_BIN(rtc_tm->tm_year);
340
341 /*
342 * Account for differences between how the RTC uses the values
343 * and how they are defined in a struct rtc_time;
344 */
345
346 if (rtc_tm->tm_year <= 69)
347 rtc_tm->tm_year += 100;
348
349 rtc_tm->tm_mon--;
350}
351
352static unsigned char days_in_mo[] =
353 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
354
355/* ioctl that supports RTC_RD_TIME and RTC_SET_TIME (read and set time/date). */
356
357static int
358rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
359 unsigned long arg)
360{
361 unsigned long flags;
362
363 switch(cmd) {
364 case RTC_RD_TIME: /* read the time/date from RTC */
365 {
366 struct rtc_time rtc_tm;
367
368 memset(&rtc_tm, 0, sizeof (struct rtc_time));
369 get_rtc_time(&rtc_tm);
370 if (copy_to_user((struct rtc_time*)arg, &rtc_tm, sizeof(struct rtc_time)))
371 return -EFAULT;
372 return 0;
373 }
374
375 case RTC_SET_TIME: /* set the RTC */
376 {
377 struct rtc_time rtc_tm;
378 unsigned char mon, day, hrs, min, sec, leap_yr;
379 unsigned int yrs;
380
381 if (!capable(CAP_SYS_TIME))
382 return -EPERM;
383
384 if (copy_from_user(&rtc_tm, (struct rtc_time*)arg, sizeof(struct rtc_time)))
385 return -EFAULT;
386
387 yrs = rtc_tm.tm_year + 1900;
388 mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
389 day = rtc_tm.tm_mday;
390 hrs = rtc_tm.tm_hour;
391 min = rtc_tm.tm_min;
392 sec = rtc_tm.tm_sec;
393
394
395 if ((yrs < 1970) || (yrs > 2069))
396 return -EINVAL;
397
398 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
399
400 if ((mon > 12) || (day == 0))
401 return -EINVAL;
402
403 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
404 return -EINVAL;
405
406 if ((hrs >= 24) || (min >= 60) || (sec >= 60))
407 return -EINVAL;
408
409 if (yrs >= 2000)
410 yrs -= 2000; /* RTC (0, 1, ... 69) */
411 else
412 yrs -= 1900; /* RTC (70, 71, ... 99) */
413
414 BIN_TO_BCD(sec);
415 BIN_TO_BCD(min);
416 BIN_TO_BCD(hrs);
417 BIN_TO_BCD(day);
418 BIN_TO_BCD(mon);
419 BIN_TO_BCD(yrs);
420
421 local_irq_save(flags);
422 local_irq_disable();
423 CMOS_WRITE(yrs, RTC_YEAR);
424 CMOS_WRITE(mon, RTC_MONTH);
425 CMOS_WRITE(day, RTC_DAY_OF_MONTH);
426 CMOS_WRITE(hrs, RTC_HOURS);
427 CMOS_WRITE(min, RTC_MINUTES);
428 CMOS_WRITE(sec, RTC_SECONDS);
429 local_irq_restore(flags);
430
431 /* Notice that at this point, the RTC is updated but
432 * the kernel is still running with the old time.
433 * You need to set that separately with settimeofday
434 * or adjtimex.
435 */
436 return 0;
437 }
438
439 case RTC_SET_CHARGE: /* set the RTC TRICKLE CHARGE register */
440 {
441 int tcs_val;
442
443 if (!capable(CAP_SYS_TIME))
444 return -EPERM;
445
446 if(copy_from_user(&tcs_val, (int*)arg, sizeof(int)))
447 return -EFAULT;
448
449 tcs_val = RTC_TCR_PATTERN | (tcs_val & 0x0F);
450 ds1302_writereg(RTC_TRICKLECHARGER, tcs_val);
451 return 0;
452 }
453 case RTC_VLOW_RD:
454 {
455 /* TODO:
456 * Implement voltage low detection support
457 */
458 printk(KERN_WARNING "DS1302: RTC Voltage Low detection"
459 " is not supported\n");
460 return 0;
461 }
462 case RTC_VLOW_SET:
463 {
464 /* TODO:
465 * Nothing to do since Voltage Low detection is not supported
466 */
467 return 0;
468 }
469 default:
470 return -ENOIOCTLCMD;
471 }
472}
473
474static void
475print_rtc_status(void)
476{
477 struct rtc_time tm;
478
479 get_rtc_time(&tm);
480
481 /*
482 * There is no way to tell if the luser has the RTC set for local
483 * time or for Universal Standard Time (GMT). Probably local though.
484 */
485
486 printk(KERN_INFO "rtc_time\t: %02d:%02d:%02d\n",
487 tm.tm_hour, tm.tm_min, tm.tm_sec);
488 printk(KERN_INFO "rtc_date\t: %04d-%02d-%02d\n",
489 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
490}
491
492/* The various file operations we support. */
493
494static struct file_operations rtc_fops = {
495 .owner = THIS_MODULE,
496 .ioctl = rtc_ioctl,
497};
498
499/* Probe for the chip by writing something to its RAM and try reading it back. */
500
501#define MAGIC_PATTERN 0x42
502
503static int __init
504ds1302_probe(void)
505{
506 int retval, res;
507
508 TK_RST_DIR(1);
509 TK_SCL_DIR(1);
510 TK_SDA_DIR(0);
511
512 /* Try to talk to timekeeper. */
513
514 ds1302_wenable();
515 start();
516 out_byte(0xc0); /* write RAM byte 0 */
517 out_byte(MAGIC_PATTERN); /* write something magic */
518 start();
519 out_byte(0xc1); /* read RAM byte 0 */
520
521 if((res = in_byte()) == MAGIC_PATTERN) {
522 stop();
523 ds1302_wdisable();
524 printk(KERN_INFO "%s: RTC found.\n", ds1302_name);
525 printk(KERN_INFO "%s: SDA, SCL, RST on PB%i, PB%i, %s%i\n",
526 ds1302_name,
527 CONFIG_ETRAX_DS1302_SDABIT,
528 CONFIG_ETRAX_DS1302_SCLBIT,
529#ifdef CONFIG_ETRAX_DS1302_RST_ON_GENERIC_PORT
530 "GENIO",
531#else
532 "PB",
533#endif
534 CONFIG_ETRAX_DS1302_RSTBIT);
535 print_rtc_status();
536 retval = 1;
537 } else {
538 stop();
539 retval = 0;
540 }
541
542 return retval;
543}
544
545
546/* Just probe for the RTC and register the device to handle the ioctl needed. */
547
548int __init
549ds1302_init(void)
550{
551 i2c_init();
552
553 if (!ds1302_probe()) {
554#ifdef CONFIG_ETRAX_DS1302_RST_ON_GENERIC_PORT
555#if CONFIG_ETRAX_DS1302_RSTBIT == 27
556 /*
557 * The only way to set g27 to output is to enable ATA.
558 *
559 * Make sure that R_GEN_CONFIG is setup correct.
560 */
561 genconfig_shadow = ((genconfig_shadow &
562 ~IO_MASK(R_GEN_CONFIG, ata)) |
563 (IO_STATE(R_GEN_CONFIG, ata, select)));
564 *R_GEN_CONFIG = genconfig_shadow;
565#elif CONFIG_ETRAX_DS1302_RSTBIT == 0
566
567 /* Set the direction of this bit to out. */
568 genconfig_shadow = ((genconfig_shadow &
569 ~IO_MASK(R_GEN_CONFIG, g0dir)) |
570 (IO_STATE(R_GEN_CONFIG, g0dir, out)));
571 *R_GEN_CONFIG = genconfig_shadow;
572#endif
573 if (!ds1302_probe()) {
574 printk(KERN_WARNING "%s: RTC not found.\n", ds1302_name);
575 return -1;
576 }
577#else
578 printk(KERN_WARNING "%s: RTC not found.\n", ds1302_name);
579 return -1;
580#endif
581 }
582 /* Initialise trickle charger */
583 ds1302_writereg(RTC_TRICKLECHARGER,
584 RTC_TCR_PATTERN |(CONFIG_ETRAX_DS1302_TRICKLE_CHARGE & 0x0F));
585 /* Start clock by resetting CLOCK_HALT */
586 ds1302_writereg(RTC_SECONDS, (ds1302_readreg(RTC_SECONDS) & 0x7F));
587 return 0;
588}
589
590static int __init ds1302_register(void)
591{
592 ds1302_init();
593 if (register_chrdev(RTC_MAJOR_NR, ds1302_name, &rtc_fops)) {
594 printk(KERN_INFO "%s: unable to get major %d for rtc\n",
595 ds1302_name, RTC_MAJOR_NR);
596 return -1;
597 }
598 return 0;
599
600}
601
602module_init(ds1302_register);
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-03 17:29:37 -0500