2 * An I2C driver for Ricoh RS5C372, R2025S/D and RV5C38[67] RTCs
4 * Copyright (C) 2005 Pavel Mironchik <pmironchik@optifacio.net>
5 * Copyright (C) 2006 Tower Technologies
6 * Copyright (C) 2008 Paul Mundt
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
13 #include <linux/i2c.h>
14 #include <linux/rtc.h>
15 #include <linux/bcd.h>
17 #define DRV_VERSION "0.6"
21 * Ricoh has a family of I2C based RTCs, which differ only slightly from
22 * each other. Differences center on pinout (e.g. how many interrupts,
23 * output clock, etc) and how the control registers are used. The '372
24 * is significant only because that's the one this driver first supported.
26 #define RS5C372_REG_SECS 0
27 #define RS5C372_REG_MINS 1
28 #define RS5C372_REG_HOURS 2
29 #define RS5C372_REG_WDAY 3
30 #define RS5C372_REG_DAY 4
31 #define RS5C372_REG_MONTH 5
32 #define RS5C372_REG_YEAR 6
33 #define RS5C372_REG_TRIM 7
34 # define RS5C372_TRIM_XSL 0x80
35 # define RS5C372_TRIM_MASK 0x7F
37 #define RS5C_REG_ALARM_A_MIN 8 /* or ALARM_W */
38 #define RS5C_REG_ALARM_A_HOURS 9
39 #define RS5C_REG_ALARM_A_WDAY 10
41 #define RS5C_REG_ALARM_B_MIN 11 /* or ALARM_D */
42 #define RS5C_REG_ALARM_B_HOURS 12
43 #define RS5C_REG_ALARM_B_WDAY 13 /* (ALARM_B only) */
45 #define RS5C_REG_CTRL1 14
46 # define RS5C_CTRL1_AALE (1 << 7) /* or WALE */
47 # define RS5C_CTRL1_BALE (1 << 6) /* or DALE */
48 # define RV5C387_CTRL1_24 (1 << 5)
49 # define RS5C372A_CTRL1_SL1 (1 << 5)
50 # define RS5C_CTRL1_CT_MASK (7 << 0)
51 # define RS5C_CTRL1_CT0 (0 << 0) /* no periodic irq */
52 # define RS5C_CTRL1_CT4 (4 << 0) /* 1 Hz level irq */
53 #define RS5C_REG_CTRL2 15
54 # define RS5C372_CTRL2_24 (1 << 5)
55 # define R2025_CTRL2_XST (1 << 5)
56 # define RS5C_CTRL2_XSTP (1 << 4) /* only if !R2025S/D */
57 # define RS5C_CTRL2_CTFG (1 << 2)
58 # define RS5C_CTRL2_AAFG (1 << 1) /* or WAFG */
59 # define RS5C_CTRL2_BAFG (1 << 0) /* or DAFG */
62 /* to read (style 1) or write registers starting at R */
63 #define RS5C_ADDR(R) (((R) << 4) | 0)
75 static const struct i2c_device_id rs5c372_id[] = {
76 { "r2025sd", rtc_r2025sd },
77 { "rs5c372a", rtc_rs5c372a },
78 { "rs5c372b", rtc_rs5c372b },
79 { "rv5c386", rtc_rv5c386 },
80 { "rv5c387a", rtc_rv5c387a },
83 MODULE_DEVICE_TABLE(i2c, rs5c372_id);
85 /* REVISIT: this assumes that:
86 * - we're in the 21st century, so it's safe to ignore the century
87 * bit for rv5c38[67] (REG_MONTH bit 7);
88 * - we should use ALARM_A not ALARM_B (may be wrong on some boards)
91 struct i2c_client *client;
92 struct rtc_device *rtc;
101 static int rs5c_get_regs(struct rs5c372 *rs5c)
103 struct i2c_client *client = rs5c->client;
104 struct i2c_msg msgs[] = {
105 { client->addr, I2C_M_RD, sizeof rs5c->buf, rs5c->buf },
108 /* This implements the third reading method from the datasheet, using
109 * an internal address that's reset after each transaction (by STOP)
110 * to 0x0f ... so we read extra registers, and skip the first one.
112 * The first method doesn't work with the iop3xx adapter driver, on at
113 * least 80219 chips; this works around that bug.
115 * The third method on the other hand doesn't work for the SMBus-only
116 * configurations, so we use the the first method there, stripping off
117 * the extra register in the process.
120 int addr = RS5C_ADDR(RS5C372_REG_SECS);
121 int size = sizeof(rs5c->buf) - 1;
123 if (i2c_smbus_read_i2c_block_data(client, addr, size,
124 rs5c->buf + 1) != size) {
125 dev_warn(&client->dev, "can't read registers\n");
129 if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
130 dev_warn(&client->dev, "can't read registers\n");
135 dev_dbg(&client->dev,
136 "%02x %02x %02x (%02x) %02x %02x %02x (%02x), "
137 "%02x %02x %02x, %02x %02x %02x; %02x %02x\n",
138 rs5c->regs[0], rs5c->regs[1], rs5c->regs[2], rs5c->regs[3],
139 rs5c->regs[4], rs5c->regs[5], rs5c->regs[6], rs5c->regs[7],
140 rs5c->regs[8], rs5c->regs[9], rs5c->regs[10], rs5c->regs[11],
141 rs5c->regs[12], rs5c->regs[13], rs5c->regs[14], rs5c->regs[15]);
146 static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
151 return bcd2bin(reg & 0x3f);
153 hour = bcd2bin(reg & 0x1f);
161 static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
164 return bin2bcd(hour);
167 return 0x20 | bin2bcd(hour - 12);
169 return 0x20 | bin2bcd(12);
172 return bin2bcd(hour);
175 static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
177 struct rs5c372 *rs5c = i2c_get_clientdata(client);
178 int status = rs5c_get_regs(rs5c);
183 tm->tm_sec = bcd2bin(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
184 tm->tm_min = bcd2bin(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
185 tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
187 tm->tm_wday = bcd2bin(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
188 tm->tm_mday = bcd2bin(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
190 /* tm->tm_mon is zero-based */
191 tm->tm_mon = bcd2bin(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
193 /* year is 1900 + tm->tm_year */
194 tm->tm_year = bcd2bin(rs5c->regs[RS5C372_REG_YEAR]) + 100;
196 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
197 "mday=%d, mon=%d, year=%d, wday=%d\n",
199 tm->tm_sec, tm->tm_min, tm->tm_hour,
200 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
202 /* rtc might need initialization */
203 return rtc_valid_tm(tm);
206 static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
208 struct rs5c372 *rs5c = i2c_get_clientdata(client);
209 unsigned char buf[8];
212 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
213 "mday=%d, mon=%d, year=%d, wday=%d\n",
215 tm->tm_sec, tm->tm_min, tm->tm_hour,
216 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
218 addr = RS5C_ADDR(RS5C372_REG_SECS);
219 buf[0] = bin2bcd(tm->tm_sec);
220 buf[1] = bin2bcd(tm->tm_min);
221 buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour);
222 buf[3] = bin2bcd(tm->tm_wday);
223 buf[4] = bin2bcd(tm->tm_mday);
224 buf[5] = bin2bcd(tm->tm_mon + 1);
225 buf[6] = bin2bcd(tm->tm_year - 100);
227 if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) {
228 dev_err(&client->dev, "%s: write error\n", __func__);
235 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
239 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
244 static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
246 struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
247 u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
250 *osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
253 dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
254 tmp &= RS5C372_TRIM_MASK;
259 t = (~t | (s8)0xc0) + 1;
273 static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
275 return rs5c372_get_datetime(to_i2c_client(dev), tm);
278 static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
280 return rs5c372_set_datetime(to_i2c_client(dev), tm);
283 #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
286 rs5c_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
288 struct i2c_client *client = to_i2c_client(dev);
289 struct rs5c372 *rs5c = i2c_get_clientdata(client);
293 buf = rs5c->regs[RS5C_REG_CTRL1];
297 /* some 327a modes use a different IRQ pin for 1Hz irqs */
298 if (rs5c->type == rtc_rs5c372a
299 && (buf & RS5C372A_CTRL1_SL1))
303 /* these irq management calls only make sense for chips
304 * which are wired up to an IRQ.
313 status = rs5c_get_regs(rs5c);
317 addr = RS5C_ADDR(RS5C_REG_CTRL1);
319 case RTC_AIE_OFF: /* alarm off */
320 buf &= ~RS5C_CTRL1_AALE;
322 case RTC_AIE_ON: /* alarm on */
323 buf |= RS5C_CTRL1_AALE;
325 case RTC_UIE_OFF: /* update off */
326 buf &= ~RS5C_CTRL1_CT_MASK;
328 case RTC_UIE_ON: /* update on */
329 buf &= ~RS5C_CTRL1_CT_MASK;
330 buf |= RS5C_CTRL1_CT4;
334 if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
335 printk(KERN_WARNING "%s: can't update alarm\n",
339 rs5c->regs[RS5C_REG_CTRL1] = buf;
345 #define rs5c_rtc_ioctl NULL
349 /* NOTE: Since RTC_WKALM_{RD,SET} were originally defined for EFI,
350 * which only exposes a polled programming interface; and since
351 * these calls map directly to those EFI requests; we don't demand
352 * we have an IRQ for this chip when we go through this API.
354 * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
355 * though, managed through RTC_AIE_{ON,OFF} requests.
358 static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
360 struct i2c_client *client = to_i2c_client(dev);
361 struct rs5c372 *rs5c = i2c_get_clientdata(client);
364 status = rs5c_get_regs(rs5c);
368 /* report alarm time */
370 t->time.tm_min = bcd2bin(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
371 t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
372 t->time.tm_mday = -1;
374 t->time.tm_year = -1;
375 t->time.tm_wday = -1;
376 t->time.tm_yday = -1;
377 t->time.tm_isdst = -1;
380 t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
381 t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
386 static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
388 struct i2c_client *client = to_i2c_client(dev);
389 struct rs5c372 *rs5c = i2c_get_clientdata(client);
391 unsigned char buf[3];
393 /* only handle up to 24 hours in the future, like RTC_ALM_SET */
394 if (t->time.tm_mday != -1
395 || t->time.tm_mon != -1
396 || t->time.tm_year != -1)
399 /* REVISIT: round up tm_sec */
401 /* if needed, disable irq (clears pending status) */
402 status = rs5c_get_regs(rs5c);
405 if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
406 addr = RS5C_ADDR(RS5C_REG_CTRL1);
407 buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
408 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
409 pr_debug("%s: can't disable alarm\n", rs5c->rtc->name);
412 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
416 buf[0] = bin2bcd(t->time.tm_min);
417 buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
418 buf[2] = 0x7f; /* any/all days */
420 for (i = 0; i < sizeof(buf); i++) {
421 addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
422 if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
423 pr_debug("%s: can't set alarm time\n", rs5c->rtc->name);
428 /* ... and maybe enable its irq */
430 addr = RS5C_ADDR(RS5C_REG_CTRL1);
431 buf[0] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
432 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0)
433 printk(KERN_WARNING "%s: can't enable alarm\n",
435 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
441 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
443 static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
447 err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
449 seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
450 osc / 1000, osc % 1000);
451 seq_printf(seq, "trim\t\t: %d\n", trim);
458 #define rs5c372_rtc_proc NULL
461 static const struct rtc_class_ops rs5c372_rtc_ops = {
462 .proc = rs5c372_rtc_proc,
463 .ioctl = rs5c_rtc_ioctl,
464 .read_time = rs5c372_rtc_read_time,
465 .set_time = rs5c372_rtc_set_time,
466 .read_alarm = rs5c_read_alarm,
467 .set_alarm = rs5c_set_alarm,
470 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
472 static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
473 struct device_attribute *attr, char *buf)
477 err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
481 return sprintf(buf, "%d\n", trim);
483 static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
485 static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
486 struct device_attribute *attr, char *buf)
490 err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
494 return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
496 static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
498 static int rs5c_sysfs_register(struct device *dev)
502 err = device_create_file(dev, &dev_attr_trim);
505 err = device_create_file(dev, &dev_attr_osc);
507 device_remove_file(dev, &dev_attr_trim);
512 static void rs5c_sysfs_unregister(struct device *dev)
514 device_remove_file(dev, &dev_attr_trim);
515 device_remove_file(dev, &dev_attr_osc);
519 static int rs5c_sysfs_register(struct device *dev)
524 static void rs5c_sysfs_unregister(struct device *dev)
530 static struct i2c_driver rs5c372_driver;
532 static int rs5c_oscillator_setup(struct rs5c372 *rs5c372)
534 unsigned char buf[2];
535 int addr, i, ret = 0;
537 if (rs5c372->type == rtc_r2025sd) {
538 if (!(rs5c372->regs[RS5C_REG_CTRL2] & R2025_CTRL2_XST))
540 rs5c372->regs[RS5C_REG_CTRL2] &= ~R2025_CTRL2_XST;
542 if (!(rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP))
544 rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
547 addr = RS5C_ADDR(RS5C_REG_CTRL1);
548 buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
549 buf[1] = rs5c372->regs[RS5C_REG_CTRL2];
552 switch (rs5c372->type) {
555 buf[1] |= RS5C372_CTRL2_24;
561 buf[0] |= RV5C387_CTRL1_24;
569 for (i = 0; i < sizeof(buf); i++) {
570 addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
571 ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
572 if (unlikely(ret < 0))
576 rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
577 rs5c372->regs[RS5C_REG_CTRL2] = buf[1];
582 static int rs5c372_probe(struct i2c_client *client,
583 const struct i2c_device_id *id)
587 struct rs5c372 *rs5c372;
590 dev_dbg(&client->dev, "%s\n", __func__);
592 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
593 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
595 * If we don't have any master mode adapter, try breaking
596 * it down in to the barest of capabilities.
598 if (i2c_check_functionality(client->adapter,
599 I2C_FUNC_SMBUS_BYTE_DATA |
600 I2C_FUNC_SMBUS_I2C_BLOCK))
603 /* Still no good, give up */
609 if (!(rs5c372 = kzalloc(sizeof(struct rs5c372), GFP_KERNEL))) {
614 rs5c372->client = client;
615 i2c_set_clientdata(client, rs5c372);
616 rs5c372->type = id->driver_data;
618 /* we read registers 0x0f then 0x00-0x0f; skip the first one */
619 rs5c372->regs = &rs5c372->buf[1];
620 rs5c372->smbus = smbus_mode;
622 err = rs5c_get_regs(rs5c372);
626 /* clock may be set for am/pm or 24 hr time */
627 switch (rs5c372->type) {
630 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
631 * so does periodic irq, except some 327a modes.
633 if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
639 if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
641 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
642 * irq, on both 386 and 387
646 dev_err(&client->dev, "unknown RTC type\n");
650 /* if the oscillator lost power and no other software (like
651 * the bootloader) set it up, do it here.
653 * The R2025S/D does this a little differently than the other
654 * parts, so we special case that..
656 err = rs5c_oscillator_setup(rs5c372);
657 if (unlikely(err < 0)) {
658 dev_err(&client->dev, "setup error\n");
662 if (rs5c372_get_datetime(client, &tm) < 0)
663 dev_warn(&client->dev, "clock needs to be set\n");
665 dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
666 ({ char *s; switch (rs5c372->type) {
667 case rtc_r2025sd: s = "r2025sd"; break;
668 case rtc_rs5c372a: s = "rs5c372a"; break;
669 case rtc_rs5c372b: s = "rs5c372b"; break;
670 case rtc_rv5c386: s = "rv5c386"; break;
671 case rtc_rv5c387a: s = "rv5c387a"; break;
672 default: s = "chip"; break;
674 rs5c372->time24 ? "24hr" : "am/pm"
677 /* REVISIT use client->irq to register alarm irq ... */
679 rs5c372->rtc = rtc_device_register(rs5c372_driver.driver.name,
680 &client->dev, &rs5c372_rtc_ops, THIS_MODULE);
682 if (IS_ERR(rs5c372->rtc)) {
683 err = PTR_ERR(rs5c372->rtc);
687 err = rs5c_sysfs_register(&client->dev);
694 rtc_device_unregister(rs5c372->rtc);
703 static int rs5c372_remove(struct i2c_client *client)
705 struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
707 rtc_device_unregister(rs5c372->rtc);
708 rs5c_sysfs_unregister(&client->dev);
713 static struct i2c_driver rs5c372_driver = {
715 .name = "rtc-rs5c372",
717 .probe = rs5c372_probe,
718 .remove = rs5c372_remove,
719 .id_table = rs5c372_id,
722 static __init int rs5c372_init(void)
724 return i2c_add_driver(&rs5c372_driver);
727 static __exit void rs5c372_exit(void)
729 i2c_del_driver(&rs5c372_driver);
732 module_init(rs5c372_init);
733 module_exit(rs5c372_exit);
736 "Pavel Mironchik <pmironchik@optifacio.net>, "
737 "Alessandro Zummo <a.zummo@towertech.it>, "
738 "Paul Mundt <lethal@linux-sh.org>");
739 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
740 MODULE_LICENSE("GPL");
741 MODULE_VERSION(DRV_VERSION);