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);
285 static int rs5c_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
287 struct i2c_client *client = to_i2c_client(dev);
288 struct rs5c372 *rs5c = i2c_get_clientdata(client);
292 buf = rs5c->regs[RS5C_REG_CTRL1];
297 status = rs5c_get_regs(rs5c);
301 addr = RS5C_ADDR(RS5C_REG_CTRL1);
303 buf |= RS5C_CTRL1_AALE;
305 buf &= ~RS5C_CTRL1_AALE;
307 if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
308 printk(KERN_WARNING "%s: can't update alarm\n",
312 rs5c->regs[RS5C_REG_CTRL1] = buf;
318 /* NOTE: Since RTC_WKALM_{RD,SET} were originally defined for EFI,
319 * which only exposes a polled programming interface; and since
320 * these calls map directly to those EFI requests; we don't demand
321 * we have an IRQ for this chip when we go through this API.
323 * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
324 * though, managed through RTC_AIE_{ON,OFF} requests.
327 static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
329 struct i2c_client *client = to_i2c_client(dev);
330 struct rs5c372 *rs5c = i2c_get_clientdata(client);
333 status = rs5c_get_regs(rs5c);
337 /* report alarm time */
339 t->time.tm_min = bcd2bin(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
340 t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
341 t->time.tm_mday = -1;
343 t->time.tm_year = -1;
344 t->time.tm_wday = -1;
345 t->time.tm_yday = -1;
346 t->time.tm_isdst = -1;
349 t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
350 t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
355 static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
357 struct i2c_client *client = to_i2c_client(dev);
358 struct rs5c372 *rs5c = i2c_get_clientdata(client);
360 unsigned char buf[3];
362 /* only handle up to 24 hours in the future, like RTC_ALM_SET */
363 if (t->time.tm_mday != -1
364 || t->time.tm_mon != -1
365 || t->time.tm_year != -1)
368 /* REVISIT: round up tm_sec */
370 /* if needed, disable irq (clears pending status) */
371 status = rs5c_get_regs(rs5c);
374 if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
375 addr = RS5C_ADDR(RS5C_REG_CTRL1);
376 buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
377 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
378 pr_debug("%s: can't disable alarm\n", rs5c->rtc->name);
381 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
385 buf[0] = bin2bcd(t->time.tm_min);
386 buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
387 buf[2] = 0x7f; /* any/all days */
389 for (i = 0; i < sizeof(buf); i++) {
390 addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
391 if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
392 pr_debug("%s: can't set alarm time\n", rs5c->rtc->name);
397 /* ... and maybe enable its irq */
399 addr = RS5C_ADDR(RS5C_REG_CTRL1);
400 buf[0] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
401 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0)
402 printk(KERN_WARNING "%s: can't enable alarm\n",
404 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
410 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
412 static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
416 err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
418 seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
419 osc / 1000, osc % 1000);
420 seq_printf(seq, "trim\t\t: %d\n", trim);
427 #define rs5c372_rtc_proc NULL
430 static const struct rtc_class_ops rs5c372_rtc_ops = {
431 .proc = rs5c372_rtc_proc,
432 .read_time = rs5c372_rtc_read_time,
433 .set_time = rs5c372_rtc_set_time,
434 .read_alarm = rs5c_read_alarm,
435 .set_alarm = rs5c_set_alarm,
436 .alarm_irq_enable = rs5c_rtc_alarm_irq_enable,
439 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
441 static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
442 struct device_attribute *attr, char *buf)
446 err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
450 return sprintf(buf, "%d\n", trim);
452 static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
454 static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
455 struct device_attribute *attr, char *buf)
459 err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
463 return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
465 static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
467 static int rs5c_sysfs_register(struct device *dev)
471 err = device_create_file(dev, &dev_attr_trim);
474 err = device_create_file(dev, &dev_attr_osc);
476 device_remove_file(dev, &dev_attr_trim);
481 static void rs5c_sysfs_unregister(struct device *dev)
483 device_remove_file(dev, &dev_attr_trim);
484 device_remove_file(dev, &dev_attr_osc);
488 static int rs5c_sysfs_register(struct device *dev)
493 static void rs5c_sysfs_unregister(struct device *dev)
499 static struct i2c_driver rs5c372_driver;
501 static int rs5c_oscillator_setup(struct rs5c372 *rs5c372)
503 unsigned char buf[2];
504 int addr, i, ret = 0;
506 if (rs5c372->type == rtc_r2025sd) {
507 if (!(rs5c372->regs[RS5C_REG_CTRL2] & R2025_CTRL2_XST))
509 rs5c372->regs[RS5C_REG_CTRL2] &= ~R2025_CTRL2_XST;
511 if (!(rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP))
513 rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
516 addr = RS5C_ADDR(RS5C_REG_CTRL1);
517 buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
518 buf[1] = rs5c372->regs[RS5C_REG_CTRL2];
521 switch (rs5c372->type) {
524 buf[1] |= RS5C372_CTRL2_24;
530 buf[0] |= RV5C387_CTRL1_24;
538 for (i = 0; i < sizeof(buf); i++) {
539 addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
540 ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
541 if (unlikely(ret < 0))
545 rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
546 rs5c372->regs[RS5C_REG_CTRL2] = buf[1];
551 static int rs5c372_probe(struct i2c_client *client,
552 const struct i2c_device_id *id)
556 struct rs5c372 *rs5c372;
559 dev_dbg(&client->dev, "%s\n", __func__);
561 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
562 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
564 * If we don't have any master mode adapter, try breaking
565 * it down in to the barest of capabilities.
567 if (i2c_check_functionality(client->adapter,
568 I2C_FUNC_SMBUS_BYTE_DATA |
569 I2C_FUNC_SMBUS_I2C_BLOCK))
572 /* Still no good, give up */
578 if (!(rs5c372 = kzalloc(sizeof(struct rs5c372), GFP_KERNEL))) {
583 rs5c372->client = client;
584 i2c_set_clientdata(client, rs5c372);
585 rs5c372->type = id->driver_data;
587 /* we read registers 0x0f then 0x00-0x0f; skip the first one */
588 rs5c372->regs = &rs5c372->buf[1];
589 rs5c372->smbus = smbus_mode;
591 err = rs5c_get_regs(rs5c372);
595 /* clock may be set for am/pm or 24 hr time */
596 switch (rs5c372->type) {
599 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
600 * so does periodic irq, except some 327a modes.
602 if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
608 if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
610 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
611 * irq, on both 386 and 387
615 dev_err(&client->dev, "unknown RTC type\n");
619 /* if the oscillator lost power and no other software (like
620 * the bootloader) set it up, do it here.
622 * The R2025S/D does this a little differently than the other
623 * parts, so we special case that..
625 err = rs5c_oscillator_setup(rs5c372);
626 if (unlikely(err < 0)) {
627 dev_err(&client->dev, "setup error\n");
631 if (rs5c372_get_datetime(client, &tm) < 0)
632 dev_warn(&client->dev, "clock needs to be set\n");
634 dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
635 ({ char *s; switch (rs5c372->type) {
636 case rtc_r2025sd: s = "r2025sd"; break;
637 case rtc_rs5c372a: s = "rs5c372a"; break;
638 case rtc_rs5c372b: s = "rs5c372b"; break;
639 case rtc_rv5c386: s = "rv5c386"; break;
640 case rtc_rv5c387a: s = "rv5c387a"; break;
641 default: s = "chip"; break;
643 rs5c372->time24 ? "24hr" : "am/pm"
646 /* REVISIT use client->irq to register alarm irq ... */
648 rs5c372->rtc = rtc_device_register(rs5c372_driver.driver.name,
649 &client->dev, &rs5c372_rtc_ops, THIS_MODULE);
651 if (IS_ERR(rs5c372->rtc)) {
652 err = PTR_ERR(rs5c372->rtc);
656 err = rs5c_sysfs_register(&client->dev);
663 rtc_device_unregister(rs5c372->rtc);
672 static int rs5c372_remove(struct i2c_client *client)
674 struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
676 rtc_device_unregister(rs5c372->rtc);
677 rs5c_sysfs_unregister(&client->dev);
682 static struct i2c_driver rs5c372_driver = {
684 .name = "rtc-rs5c372",
686 .probe = rs5c372_probe,
687 .remove = rs5c372_remove,
688 .id_table = rs5c372_id,
691 static __init int rs5c372_init(void)
693 return i2c_add_driver(&rs5c372_driver);
696 static __exit void rs5c372_exit(void)
698 i2c_del_driver(&rs5c372_driver);
701 module_init(rs5c372_init);
702 module_exit(rs5c372_exit);
705 "Pavel Mironchik <pmironchik@optifacio.net>, "
706 "Alessandro Zummo <a.zummo@towertech.it>, "
707 "Paul Mundt <lethal@linux-sh.org>");
708 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
709 MODULE_LICENSE("GPL");
710 MODULE_VERSION(DRV_VERSION);