1 /*!***************************************************************************
3 *! FILE NAME : ds1302.c
5 *! DESCRIPTION: Implements an interface for the DS1302 RTC through Etrax I/O
7 *! Functions exported: ds1302_readreg, ds1302_writereg, ds1302_init, get_rtc_status
10 *! Revision 1.9 2003/07/04 08:27:37 starvik
11 *! Merge of Linux 2.5.74
13 *! Revision 1.8 2003/04/09 05:20:47 starvik
14 *! Merge of Linux 2.5.67
16 *! Revision 1.6 2003/01/09 14:42:51 starvik
17 *! Merge of Linux 2.5.55
19 *! Revision 1.4 2002/12/11 13:13:57 starvik
20 *! Added arch/ to v10 specific includes
21 *! Added fix from Linux 2.4 in serial.c (flush_to_flip_buffer)
23 *! Revision 1.3 2002/11/20 11:56:10 starvik
24 *! Merge of Linux 2.5.48
26 *! Revision 1.2 2002/11/18 13:16:06 starvik
27 *! Linux 2.5 port of latest 2.4 drivers
29 *! Revision 1.15 2002/10/11 16:14:33 johana
30 *! Added CONFIG_ETRAX_DS1302_TRICKLE_CHARGE and initial setting of the
31 *! trcklecharge register.
33 *! Revision 1.14 2002/10/10 12:15:38 magnusmn
34 *! Added support for having the RST signal on bit g0
36 *! Revision 1.13 2002/05/29 15:16:08 johana
37 *! Removed unused variables.
39 *! Revision 1.12 2002/04/10 15:35:25 johana
40 *! Moved probe function closer to init function and marked it __init.
42 *! Revision 1.11 2001/06/14 12:35:52 jonashg
43 *! The ATA hack is back. It is unfortunately the only way to set g27 to output.
45 *! Revision 1.9 2001/06/14 10:00:14 jonashg
46 *! No need for tempudelay to be inline anymore (had to adjust the usec to
47 *! loops conversion because of this to make it slow enough to be a udelay).
49 *! Revision 1.8 2001/06/14 08:06:32 jonashg
50 *! Made tempudelay delay usecs (well, just a tad more).
52 *! Revision 1.7 2001/06/13 14:18:11 jonashg
53 *! Only allow processes with SYS_TIME capability to set time and charge.
55 *! Revision 1.6 2001/06/12 15:22:07 jonashg
56 *! * Made init function __init.
57 *! * Parameter to out_byte() is unsigned char.
58 *! * The magic number 42 has got a name.
59 *! * Removed comment about /proc (nothing is exported there).
61 *! Revision 1.5 2001/06/12 14:35:13 jonashg
62 *! Gave the module a name and added it to printk's.
64 *! Revision 1.4 2001/05/31 14:53:40 jonashg
65 *! Made tempudelay() inline so that the watchdog doesn't reset (see
68 *! Revision 1.3 2001/03/26 16:03:06 bjornw
69 *! Needs linux/config.h
71 *! Revision 1.2 2001/03/20 19:42:00 bjornw
72 *! Use the ETRAX prefix on the DS1302 options
74 *! Revision 1.1 2001/03/20 09:13:50 magnusmn
77 *! Revision 1.10 2000/07/05 15:38:23 bjornw
78 *! Dont update kernel time when a RTC_SET_TIME is done
80 *! Revision 1.9 2000/03/02 15:42:59 macce
81 *! * Hack to make RTC work on all 2100/2400
83 *! Revision 1.8 2000/02/23 16:59:18 torbjore
84 *! added setup of R_GEN_CONFIG when RTC is connected to the generic port.
86 *! Revision 1.7 2000/01/17 15:51:43 johana
87 *! Added RTC_SET_CHARGE ioctl to enable trickle charger.
89 *! Revision 1.6 1999/10/27 13:19:47 bjornw
90 *! Added update_xtime_from_cmos which reads back the updated RTC into the kernel.
91 *! /dev/rtc calls it now.
93 *! Revision 1.5 1999/10/27 12:39:37 bjornw
94 *! Disabled superuser check. Anyone can now set the time.
96 *! Revision 1.4 1999/09/02 13:27:46 pkj
97 *! Added shadow for R_PORT_PB_CONFIG.
98 *! Renamed port_g_shadow to port_g_data_shadow.
100 *! Revision 1.3 1999/09/02 08:28:06 pkj
101 *! Made it possible to select either port PB or the generic port for the RST
102 *! signal line to the DS1302 RTC.
103 *! Also make sure the RST bit is configured as output on Port PB (if used).
105 *! Revision 1.2 1999/09/01 14:47:20 bjornw
106 *! Added support for /dev/rtc operations with ioctl RD_TIME and SET_TIME to read
107 *! and set the date. Register as major 121.
109 *! Revision 1.1 1999/09/01 09:45:29 bjornw
110 *! Implemented a DS1302 RTC driver.
113 *! ---------------------------------------------------------------------------
115 *! (C) Copyright 1999, 2000, 2001 Axis Communications AB, LUND, SWEDEN
117 *! $Id: ds1302.c,v 1.9 2003/07/04 08:27:37 starvik Exp $
119 *!***************************************************************************/
121 #include <linux/config.h>
123 #include <linux/fs.h>
124 #include <linux/init.h>
125 #include <linux/mm.h>
126 #include <linux/module.h>
127 #include <linux/miscdevice.h>
128 #include <linux/delay.h>
129 #include <linux/bcd.h>
131 #include <asm/uaccess.h>
132 #include <asm/system.h>
133 #include <asm/arch/svinto.h>
137 #define RTC_MAJOR_NR 121 /* local major, change later */
139 static const char ds1302_name[] = "ds1302";
141 /* The DS1302 might be connected to different bits on different products.
142 * It has three signals - SDA, SCL and RST. RST and SCL are always outputs,
143 * but SDA can have a selected direction.
144 * For now, only PORT_PB is hardcoded.
147 /* The RST bit may be on either the Generic Port or Port PB. */
148 #ifdef CONFIG_ETRAX_DS1302_RST_ON_GENERIC_PORT
149 #define TK_RST_OUT(x) REG_SHADOW_SET(R_PORT_G_DATA, port_g_data_shadow, CONFIG_ETRAX_DS1302_RSTBIT, x)
150 #define TK_RST_DIR(x)
152 #define TK_RST_OUT(x) REG_SHADOW_SET(R_PORT_PB_DATA, port_pb_data_shadow, CONFIG_ETRAX_DS1302_RSTBIT, x)
153 #define TK_RST_DIR(x) REG_SHADOW_SET(R_PORT_PB_DIR, port_pb_dir_shadow, CONFIG_ETRAX_DS1302_RSTBIT, x)
157 #define TK_SDA_OUT(x) REG_SHADOW_SET(R_PORT_PB_DATA, port_pb_data_shadow, CONFIG_ETRAX_DS1302_SDABIT, x)
158 #define TK_SCL_OUT(x) REG_SHADOW_SET(R_PORT_PB_DATA, port_pb_data_shadow, CONFIG_ETRAX_DS1302_SCLBIT, x)
160 #define TK_SDA_IN() ((*R_PORT_PB_READ >> CONFIG_ETRAX_DS1302_SDABIT) & 1)
161 /* 1 is out, 0 is in */
162 #define TK_SDA_DIR(x) REG_SHADOW_SET(R_PORT_PB_DIR, port_pb_dir_shadow, CONFIG_ETRAX_DS1302_SDABIT, x)
163 #define TK_SCL_DIR(x) REG_SHADOW_SET(R_PORT_PB_DIR, port_pb_dir_shadow, CONFIG_ETRAX_DS1302_SCLBIT, x)
167 * The reason for tempudelay and not udelay is that loops_per_usec
168 * (used in udelay) is not set when functions here are called from time.c
171 static void tempudelay(int usecs)
175 for(loops = usecs * 12; loops > 0; loops--)
182 out_byte(unsigned char x)
187 /* The chip latches incoming bits on the rising edge of SCL. */
204 /* Read byte. Bits come LSB first, on the falling edge of SCL.
205 * Assume SDA is in input direction already.
213 x |= (TK_SDA_IN() << 7);
221 /* Prepares for a transaction by de-activating RST (active-low). */
233 /* Ends a transaction by taking RST active again. */
242 /* Enable writing. */
248 out_byte(0x8e); /* Write control register */
249 out_byte(0x00); /* Disable write protect bit 7 = 0 */
253 /* Disable writing. */
256 ds1302_wdisable(void)
259 out_byte(0x8e); /* Write control register */
260 out_byte(0x80); /* Disable write protect bit 7 = 0 */
266 /* Read a byte from the selected register in the DS1302. */
269 ds1302_readreg(int reg)
274 out_byte(0x81 | (reg << 1)); /* read register */
281 /* Write a byte to the selected register. */
284 ds1302_writereg(int reg, unsigned char val)
288 out_byte(0x80 | (reg << 1)); /* write register */
295 get_rtc_time(struct rtc_time *rtc_tm)
299 local_irq_save(flags);
302 rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);
303 rtc_tm->tm_min = CMOS_READ(RTC_MINUTES);
304 rtc_tm->tm_hour = CMOS_READ(RTC_HOURS);
305 rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
306 rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);
307 rtc_tm->tm_year = CMOS_READ(RTC_YEAR);
309 local_irq_restore(flags);
311 BCD_TO_BIN(rtc_tm->tm_sec);
312 BCD_TO_BIN(rtc_tm->tm_min);
313 BCD_TO_BIN(rtc_tm->tm_hour);
314 BCD_TO_BIN(rtc_tm->tm_mday);
315 BCD_TO_BIN(rtc_tm->tm_mon);
316 BCD_TO_BIN(rtc_tm->tm_year);
319 * Account for differences between how the RTC uses the values
320 * and how they are defined in a struct rtc_time;
323 if (rtc_tm->tm_year <= 69)
324 rtc_tm->tm_year += 100;
329 static unsigned char days_in_mo[] =
330 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
332 /* ioctl that supports RTC_RD_TIME and RTC_SET_TIME (read and set time/date). */
335 rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
341 case RTC_RD_TIME: /* read the time/date from RTC */
343 struct rtc_time rtc_tm;
345 memset(&rtc_tm, 0, sizeof (struct rtc_time));
346 get_rtc_time(&rtc_tm);
347 if (copy_to_user((struct rtc_time*)arg, &rtc_tm, sizeof(struct rtc_time)))
352 case RTC_SET_TIME: /* set the RTC */
354 struct rtc_time rtc_tm;
355 unsigned char mon, day, hrs, min, sec, leap_yr;
358 if (!capable(CAP_SYS_TIME))
361 if (copy_from_user(&rtc_tm, (struct rtc_time*)arg, sizeof(struct rtc_time)))
364 yrs = rtc_tm.tm_year + 1900;
365 mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
366 day = rtc_tm.tm_mday;
367 hrs = rtc_tm.tm_hour;
372 if ((yrs < 1970) || (yrs > 2069))
375 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
377 if ((mon > 12) || (day == 0))
380 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
383 if ((hrs >= 24) || (min >= 60) || (sec >= 60))
387 yrs -= 2000; /* RTC (0, 1, ... 69) */
389 yrs -= 1900; /* RTC (70, 71, ... 99) */
398 local_irq_save(flags);
400 CMOS_WRITE(yrs, RTC_YEAR);
401 CMOS_WRITE(mon, RTC_MONTH);
402 CMOS_WRITE(day, RTC_DAY_OF_MONTH);
403 CMOS_WRITE(hrs, RTC_HOURS);
404 CMOS_WRITE(min, RTC_MINUTES);
405 CMOS_WRITE(sec, RTC_SECONDS);
406 local_irq_restore(flags);
408 /* Notice that at this point, the RTC is updated but
409 * the kernel is still running with the old time.
410 * You need to set that separately with settimeofday
416 case RTC_SET_CHARGE: /* set the RTC TRICKLE CHARGE register */
420 if (!capable(CAP_SYS_TIME))
423 if(copy_from_user(&tcs_val, (int*)arg, sizeof(int)))
426 tcs_val = RTC_TCR_PATTERN | (tcs_val & 0x0F);
427 ds1302_writereg(RTC_TRICKLECHARGER, tcs_val);
436 get_rtc_status(char *buf)
446 * There is no way to tell if the luser has the RTC set for local
447 * time or for Universal Standard Time (GMT). Probably local though.
451 "rtc_time\t: %02d:%02d:%02d\n"
452 "rtc_date\t: %04d-%02d-%02d\n",
453 tm.tm_hour, tm.tm_min, tm.tm_sec,
454 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
460 /* The various file operations we support. */
462 static struct file_operations rtc_fops = {
463 .owner = THIS_MODULE,
467 /* Probe for the chip by writing something to its RAM and try reading it back. */
469 #define MAGIC_PATTERN 0x42
480 /* Try to talk to timekeeper. */
484 out_byte(0xc0); /* write RAM byte 0 */
485 out_byte(MAGIC_PATTERN); /* write something magic */
487 out_byte(0xc1); /* read RAM byte 0 */
489 if((res = in_byte()) == MAGIC_PATTERN) {
493 printk("%s: RTC found.\n", ds1302_name);
494 printk("%s: SDA, SCL, RST on PB%i, PB%i, %s%i\n",
496 CONFIG_ETRAX_DS1302_SDABIT,
497 CONFIG_ETRAX_DS1302_SCLBIT,
498 #ifdef CONFIG_ETRAX_DS1302_RST_ON_GENERIC_PORT
503 CONFIG_ETRAX_DS1302_RSTBIT);
509 printk("%s: RTC not found.\n", ds1302_name);
517 /* Just probe for the RTC and register the device to handle the ioctl needed. */
522 if (!ds1302_probe()) {
523 #ifdef CONFIG_ETRAX_DS1302_RST_ON_GENERIC_PORT
524 #if CONFIG_ETRAX_DS1302_RSTBIT == 27
526 * The only way to set g27 to output is to enable ATA.
528 * Make sure that R_GEN_CONFIG is setup correct.
530 genconfig_shadow = ((genconfig_shadow &
531 ~IO_MASK(R_GEN_CONFIG, ata)) |
532 (IO_STATE(R_GEN_CONFIG, ata, select)));
533 *R_GEN_CONFIG = genconfig_shadow;
534 #elif CONFIG_ETRAX_DS1302_RSTBIT == 0
536 /* Set the direction of this bit to out. */
537 genconfig_shadow = ((genconfig_shadow &
538 ~IO_MASK(R_GEN_CONFIG, g0dir)) |
539 (IO_STATE(R_GEN_CONFIG, g0dir, out)));
540 *R_GEN_CONFIG = genconfig_shadow;
549 /* Initialise trickle charger */
550 ds1302_writereg(RTC_TRICKLECHARGER,
551 RTC_TCR_PATTERN |(CONFIG_ETRAX_DS1302_TRICKLE_CHARGE & 0x0F));
555 static int __init ds1302_register(void)
558 if (register_chrdev(RTC_MAJOR_NR, ds1302_name, &rtc_fops)) {
559 printk(KERN_INFO "%s: unable to get major %d for rtc\n",
560 ds1302_name, RTC_MAJOR_NR);
567 module_init(ds1302_register);