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>
16 #include <linux/slab.h>
18 #define DRV_VERSION "0.6"
22 * Ricoh has a family of I2C based RTCs, which differ only slightly from
23 * each other. Differences center on pinout (e.g. how many interrupts,
24 * output clock, etc) and how the control registers are used. The '372
25 * is significant only because that's the one this driver first supported.
27 #define RS5C372_REG_SECS 0
28 #define RS5C372_REG_MINS 1
29 #define RS5C372_REG_HOURS 2
30 #define RS5C372_REG_WDAY 3
31 #define RS5C372_REG_DAY 4
32 #define RS5C372_REG_MONTH 5
33 #define RS5C372_REG_YEAR 6
34 #define RS5C372_REG_TRIM 7
35 # define RS5C372_TRIM_XSL 0x80
36 # define RS5C372_TRIM_MASK 0x7F
38 #define RS5C_REG_ALARM_A_MIN 8 /* or ALARM_W */
39 #define RS5C_REG_ALARM_A_HOURS 9
40 #define RS5C_REG_ALARM_A_WDAY 10
42 #define RS5C_REG_ALARM_B_MIN 11 /* or ALARM_D */
43 #define RS5C_REG_ALARM_B_HOURS 12
44 #define RS5C_REG_ALARM_B_WDAY 13 /* (ALARM_B only) */
46 #define RS5C_REG_CTRL1 14
47 # define RS5C_CTRL1_AALE (1 << 7) /* or WALE */
48 # define RS5C_CTRL1_BALE (1 << 6) /* or DALE */
49 # define RV5C387_CTRL1_24 (1 << 5)
50 # define RS5C372A_CTRL1_SL1 (1 << 5)
51 # define RS5C_CTRL1_CT_MASK (7 << 0)
52 # define RS5C_CTRL1_CT0 (0 << 0) /* no periodic irq */
53 # define RS5C_CTRL1_CT4 (4 << 0) /* 1 Hz level irq */
54 #define RS5C_REG_CTRL2 15
55 # define RS5C372_CTRL2_24 (1 << 5)
56 # define R2025_CTRL2_XST (1 << 5)
57 # define RS5C_CTRL2_XSTP (1 << 4) /* only if !R2025S/D */
58 # define RS5C_CTRL2_CTFG (1 << 2)
59 # define RS5C_CTRL2_AAFG (1 << 1) /* or WAFG */
60 # define RS5C_CTRL2_BAFG (1 << 0) /* or DAFG */
63 /* to read (style 1) or write registers starting at R */
64 #define RS5C_ADDR(R) (((R) << 4) | 0)
76 static const struct i2c_device_id rs5c372_id[] = {
77 { "r2025sd", rtc_r2025sd },
78 { "rs5c372a", rtc_rs5c372a },
79 { "rs5c372b", rtc_rs5c372b },
80 { "rv5c386", rtc_rv5c386 },
81 { "rv5c387a", rtc_rv5c387a },
84 MODULE_DEVICE_TABLE(i2c, rs5c372_id);
86 /* REVISIT: this assumes that:
87 * - we're in the 21st century, so it's safe to ignore the century
88 * bit for rv5c38[67] (REG_MONTH bit 7);
89 * - we should use ALARM_A not ALARM_B (may be wrong on some boards)
92 struct i2c_client *client;
93 struct rtc_device *rtc;
102 static int rs5c_get_regs(struct rs5c372 *rs5c)
104 struct i2c_client *client = rs5c->client;
105 struct i2c_msg msgs[] = {
106 { client->addr, I2C_M_RD, sizeof rs5c->buf, rs5c->buf },
109 /* This implements the third reading method from the datasheet, using
110 * an internal address that's reset after each transaction (by STOP)
111 * to 0x0f ... so we read extra registers, and skip the first one.
113 * The first method doesn't work with the iop3xx adapter driver, on at
114 * least 80219 chips; this works around that bug.
116 * The third method on the other hand doesn't work for the SMBus-only
117 * configurations, so we use the the first method there, stripping off
118 * the extra register in the process.
121 int addr = RS5C_ADDR(RS5C372_REG_SECS);
122 int size = sizeof(rs5c->buf) - 1;
124 if (i2c_smbus_read_i2c_block_data(client, addr, size,
125 rs5c->buf + 1) != size) {
126 dev_warn(&client->dev, "can't read registers\n");
130 if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
131 dev_warn(&client->dev, "can't read registers\n");
136 dev_dbg(&client->dev,
137 "%02x %02x %02x (%02x) %02x %02x %02x (%02x), "
138 "%02x %02x %02x, %02x %02x %02x; %02x %02x\n",
139 rs5c->regs[0], rs5c->regs[1], rs5c->regs[2], rs5c->regs[3],
140 rs5c->regs[4], rs5c->regs[5], rs5c->regs[6], rs5c->regs[7],
141 rs5c->regs[8], rs5c->regs[9], rs5c->regs[10], rs5c->regs[11],
142 rs5c->regs[12], rs5c->regs[13], rs5c->regs[14], rs5c->regs[15]);
147 static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
152 return bcd2bin(reg & 0x3f);
154 hour = bcd2bin(reg & 0x1f);
162 static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
165 return bin2bcd(hour);
168 return 0x20 | bin2bcd(hour - 12);
170 return 0x20 | bin2bcd(12);
173 return bin2bcd(hour);
176 static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
178 struct rs5c372 *rs5c = i2c_get_clientdata(client);
179 int status = rs5c_get_regs(rs5c);
184 tm->tm_sec = bcd2bin(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
185 tm->tm_min = bcd2bin(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
186 tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
188 tm->tm_wday = bcd2bin(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
189 tm->tm_mday = bcd2bin(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
191 /* tm->tm_mon is zero-based */
192 tm->tm_mon = bcd2bin(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
194 /* year is 1900 + tm->tm_year */
195 tm->tm_year = bcd2bin(rs5c->regs[RS5C372_REG_YEAR]) + 100;
197 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
198 "mday=%d, mon=%d, year=%d, wday=%d\n",
200 tm->tm_sec, tm->tm_min, tm->tm_hour,
201 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
203 /* rtc might need initialization */
204 return rtc_valid_tm(tm);
207 static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
209 struct rs5c372 *rs5c = i2c_get_clientdata(client);
210 unsigned char buf[7];
213 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
214 "mday=%d, mon=%d, year=%d, wday=%d\n",
216 tm->tm_sec, tm->tm_min, tm->tm_hour,
217 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
219 addr = RS5C_ADDR(RS5C372_REG_SECS);
220 buf[0] = bin2bcd(tm->tm_sec);
221 buf[1] = bin2bcd(tm->tm_min);
222 buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour);
223 buf[3] = bin2bcd(tm->tm_wday);
224 buf[4] = bin2bcd(tm->tm_mday);
225 buf[5] = bin2bcd(tm->tm_mon + 1);
226 buf[6] = bin2bcd(tm->tm_year - 100);
228 if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) {
229 dev_err(&client->dev, "%s: write error\n", __func__);
236 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
240 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
245 static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
247 struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
248 u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
251 *osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
254 dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
255 tmp &= RS5C372_TRIM_MASK;
260 t = (~t | (s8)0xc0) + 1;
274 static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
276 return rs5c372_get_datetime(to_i2c_client(dev), tm);
279 static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
281 return rs5c372_set_datetime(to_i2c_client(dev), tm);
284 #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
287 rs5c_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
289 struct i2c_client *client = to_i2c_client(dev);
290 struct rs5c372 *rs5c = i2c_get_clientdata(client);
294 buf = rs5c->regs[RS5C_REG_CTRL1];
298 /* some 327a modes use a different IRQ pin for 1Hz irqs */
299 if (rs5c->type == rtc_rs5c372a
300 && (buf & RS5C372A_CTRL1_SL1))
304 /* these irq management calls only make sense for chips
305 * which are wired up to an IRQ.
314 status = rs5c_get_regs(rs5c);
318 addr = RS5C_ADDR(RS5C_REG_CTRL1);
320 case RTC_AIE_OFF: /* alarm off */
321 buf &= ~RS5C_CTRL1_AALE;
323 case RTC_AIE_ON: /* alarm on */
324 buf |= RS5C_CTRL1_AALE;
326 case RTC_UIE_OFF: /* update off */
327 buf &= ~RS5C_CTRL1_CT_MASK;
329 case RTC_UIE_ON: /* update on */
330 buf &= ~RS5C_CTRL1_CT_MASK;
331 buf |= RS5C_CTRL1_CT4;
335 if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
336 printk(KERN_WARNING "%s: can't update alarm\n",
340 rs5c->regs[RS5C_REG_CTRL1] = buf;
346 #define rs5c_rtc_ioctl NULL
350 /* NOTE: Since RTC_WKALM_{RD,SET} were originally defined for EFI,
351 * which only exposes a polled programming interface; and since
352 * these calls map directly to those EFI requests; we don't demand
353 * we have an IRQ for this chip when we go through this API.
355 * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
356 * though, managed through RTC_AIE_{ON,OFF} requests.
359 static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
361 struct i2c_client *client = to_i2c_client(dev);
362 struct rs5c372 *rs5c = i2c_get_clientdata(client);
365 status = rs5c_get_regs(rs5c);
369 /* report alarm time */
371 t->time.tm_min = bcd2bin(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
372 t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
373 t->time.tm_mday = -1;
375 t->time.tm_year = -1;
376 t->time.tm_wday = -1;
377 t->time.tm_yday = -1;
378 t->time.tm_isdst = -1;
381 t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
382 t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
387 static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
389 struct i2c_client *client = to_i2c_client(dev);
390 struct rs5c372 *rs5c = i2c_get_clientdata(client);
392 unsigned char buf[3];
394 /* only handle up to 24 hours in the future, like RTC_ALM_SET */
395 if (t->time.tm_mday != -1
396 || t->time.tm_mon != -1
397 || t->time.tm_year != -1)
400 /* REVISIT: round up tm_sec */
402 /* if needed, disable irq (clears pending status) */
403 status = rs5c_get_regs(rs5c);
406 if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
407 addr = RS5C_ADDR(RS5C_REG_CTRL1);
408 buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
409 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
410 pr_debug("%s: can't disable alarm\n", rs5c->rtc->name);
413 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
417 buf[0] = bin2bcd(t->time.tm_min);
418 buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
419 buf[2] = 0x7f; /* any/all days */
421 for (i = 0; i < sizeof(buf); i++) {
422 addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
423 if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
424 pr_debug("%s: can't set alarm time\n", rs5c->rtc->name);
429 /* ... and maybe enable its irq */
431 addr = RS5C_ADDR(RS5C_REG_CTRL1);
432 buf[0] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
433 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0)
434 printk(KERN_WARNING "%s: can't enable alarm\n",
436 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
442 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
444 static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
448 err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
450 seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
451 osc / 1000, osc % 1000);
452 seq_printf(seq, "trim\t\t: %d\n", trim);
459 #define rs5c372_rtc_proc NULL
462 static const struct rtc_class_ops rs5c372_rtc_ops = {
463 .proc = rs5c372_rtc_proc,
464 .ioctl = rs5c_rtc_ioctl,
465 .read_time = rs5c372_rtc_read_time,
466 .set_time = rs5c372_rtc_set_time,
467 .read_alarm = rs5c_read_alarm,
468 .set_alarm = rs5c_set_alarm,
471 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
473 static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
474 struct device_attribute *attr, char *buf)
478 err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
482 return sprintf(buf, "%d\n", trim);
484 static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
486 static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
487 struct device_attribute *attr, char *buf)
491 err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
495 return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
497 static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
499 static int rs5c_sysfs_register(struct device *dev)
503 err = device_create_file(dev, &dev_attr_trim);
506 err = device_create_file(dev, &dev_attr_osc);
508 device_remove_file(dev, &dev_attr_trim);
513 static void rs5c_sysfs_unregister(struct device *dev)
515 device_remove_file(dev, &dev_attr_trim);
516 device_remove_file(dev, &dev_attr_osc);
520 static int rs5c_sysfs_register(struct device *dev)
525 static void rs5c_sysfs_unregister(struct device *dev)
531 static struct i2c_driver rs5c372_driver;
533 static int rs5c_oscillator_setup(struct rs5c372 *rs5c372)
535 unsigned char buf[2];
536 int addr, i, ret = 0;
538 if (rs5c372->type == rtc_r2025sd) {
539 if (!(rs5c372->regs[RS5C_REG_CTRL2] & R2025_CTRL2_XST))
541 rs5c372->regs[RS5C_REG_CTRL2] &= ~R2025_CTRL2_XST;
543 if (!(rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP))
545 rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
548 addr = RS5C_ADDR(RS5C_REG_CTRL1);
549 buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
550 buf[1] = rs5c372->regs[RS5C_REG_CTRL2];
553 switch (rs5c372->type) {
556 buf[1] |= RS5C372_CTRL2_24;
562 buf[0] |= RV5C387_CTRL1_24;
570 for (i = 0; i < sizeof(buf); i++) {
571 addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
572 ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
573 if (unlikely(ret < 0))
577 rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
578 rs5c372->regs[RS5C_REG_CTRL2] = buf[1];
583 static int rs5c372_probe(struct i2c_client *client,
584 const struct i2c_device_id *id)
588 struct rs5c372 *rs5c372;
591 dev_dbg(&client->dev, "%s\n", __func__);
593 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
594 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
596 * If we don't have any master mode adapter, try breaking
597 * it down in to the barest of capabilities.
599 if (i2c_check_functionality(client->adapter,
600 I2C_FUNC_SMBUS_BYTE_DATA |
601 I2C_FUNC_SMBUS_I2C_BLOCK))
604 /* Still no good, give up */
610 if (!(rs5c372 = kzalloc(sizeof(struct rs5c372), GFP_KERNEL))) {
615 rs5c372->client = client;
616 i2c_set_clientdata(client, rs5c372);
617 rs5c372->type = id->driver_data;
619 /* we read registers 0x0f then 0x00-0x0f; skip the first one */
620 rs5c372->regs = &rs5c372->buf[1];
621 rs5c372->smbus = smbus_mode;
623 err = rs5c_get_regs(rs5c372);
627 /* clock may be set for am/pm or 24 hr time */
628 switch (rs5c372->type) {
631 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
632 * so does periodic irq, except some 327a modes.
634 if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
640 if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
642 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
643 * irq, on both 386 and 387
647 dev_err(&client->dev, "unknown RTC type\n");
651 /* if the oscillator lost power and no other software (like
652 * the bootloader) set it up, do it here.
654 * The R2025S/D does this a little differently than the other
655 * parts, so we special case that..
657 err = rs5c_oscillator_setup(rs5c372);
658 if (unlikely(err < 0)) {
659 dev_err(&client->dev, "setup error\n");
663 if (rs5c372_get_datetime(client, &tm) < 0)
664 dev_warn(&client->dev, "clock needs to be set\n");
666 dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
667 ({ char *s; switch (rs5c372->type) {
668 case rtc_r2025sd: s = "r2025sd"; break;
669 case rtc_rs5c372a: s = "rs5c372a"; break;
670 case rtc_rs5c372b: s = "rs5c372b"; break;
671 case rtc_rv5c386: s = "rv5c386"; break;
672 case rtc_rv5c387a: s = "rv5c387a"; break;
673 default: s = "chip"; break;
675 rs5c372->time24 ? "24hr" : "am/pm"
678 /* REVISIT use client->irq to register alarm irq ... */
680 rs5c372->rtc = rtc_device_register(rs5c372_driver.driver.name,
681 &client->dev, &rs5c372_rtc_ops, THIS_MODULE);
683 if (IS_ERR(rs5c372->rtc)) {
684 err = PTR_ERR(rs5c372->rtc);
688 err = rs5c_sysfs_register(&client->dev);
695 rtc_device_unregister(rs5c372->rtc);
704 static int rs5c372_remove(struct i2c_client *client)
706 struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
708 rtc_device_unregister(rs5c372->rtc);
709 rs5c_sysfs_unregister(&client->dev);
714 static struct i2c_driver rs5c372_driver = {
716 .name = "rtc-rs5c372",
718 .probe = rs5c372_probe,
719 .remove = rs5c372_remove,
720 .id_table = rs5c372_id,
723 static __init int rs5c372_init(void)
725 return i2c_add_driver(&rs5c372_driver);
728 static __exit void rs5c372_exit(void)
730 i2c_del_driver(&rs5c372_driver);
733 module_init(rs5c372_init);
734 module_exit(rs5c372_exit);
737 "Pavel Mironchik <pmironchik@optifacio.net>, "
738 "Alessandro Zummo <a.zummo@towertech.it>, "
739 "Paul Mundt <lethal@linux-sh.org>");
740 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
741 MODULE_LICENSE("GPL");
742 MODULE_VERSION(DRV_VERSION);