2 * Driver for Epson's RTC module RX-8025 SA/NB
4 * Copyright (C) 2009 Wolfgang Grandegger <wg@grandegger.com>
6 * Copyright (C) 2005 by Digi International Inc.
9 * Modified by fengjh at rising.com.cn
10 * <http://lists.lm-sensors.org/mailman/listinfo/lm-sensors>
13 * Code cleanup by Sergei Poselenov, <sposelenov@emcraft.com>
14 * Converted to new style by Wolfgang Grandegger <wg@grandegger.com>
15 * Alarm and periodic interrupt added by Dmitry Rakhchev <rda@emcraft.com>
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License
19 * version 2 as published by the Free Software Foundation.
21 #include <linux/bcd.h>
22 #include <linux/bitops.h>
23 #include <linux/i2c.h>
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/rtc.h>
28 /* Register definitions */
29 #define RX8025_REG_SEC 0x00
30 #define RX8025_REG_MIN 0x01
31 #define RX8025_REG_HOUR 0x02
32 #define RX8025_REG_WDAY 0x03
33 #define RX8025_REG_MDAY 0x04
34 #define RX8025_REG_MONTH 0x05
35 #define RX8025_REG_YEAR 0x06
36 #define RX8025_REG_DIGOFF 0x07
37 #define RX8025_REG_ALWMIN 0x08
38 #define RX8025_REG_ALWHOUR 0x09
39 #define RX8025_REG_ALWWDAY 0x0a
40 #define RX8025_REG_ALDMIN 0x0b
41 #define RX8025_REG_ALDHOUR 0x0c
42 /* 0x0d is reserved */
43 #define RX8025_REG_CTRL1 0x0e
44 #define RX8025_REG_CTRL2 0x0f
46 #define RX8025_BIT_CTRL1_CT (7 << 0)
47 /* 1 Hz periodic level irq */
48 #define RX8025_BIT_CTRL1_CT_1HZ 4
49 #define RX8025_BIT_CTRL1_TEST BIT(3)
50 #define RX8025_BIT_CTRL1_1224 BIT(5)
51 #define RX8025_BIT_CTRL1_DALE BIT(6)
52 #define RX8025_BIT_CTRL1_WALE BIT(7)
54 #define RX8025_BIT_CTRL2_DAFG BIT(0)
55 #define RX8025_BIT_CTRL2_WAFG BIT(1)
56 #define RX8025_BIT_CTRL2_CTFG BIT(2)
57 #define RX8025_BIT_CTRL2_PON BIT(4)
58 #define RX8025_BIT_CTRL2_XST BIT(5)
59 #define RX8025_BIT_CTRL2_VDET BIT(6)
61 /* Clock precision adjustment */
62 #define RX8025_ADJ_RESOLUTION 3050 /* in ppb */
63 #define RX8025_ADJ_DATA_MAX 62
64 #define RX8025_ADJ_DATA_MIN -62
66 static const struct i2c_device_id rx8025_id[] = {
70 MODULE_DEVICE_TABLE(i2c, rx8025_id);
73 struct i2c_client *client;
74 struct rtc_device *rtc;
78 static s32 rx8025_read_reg(const struct i2c_client *client, u8 number)
80 return i2c_smbus_read_byte_data(client, number << 4);
83 static int rx8025_read_regs(const struct i2c_client *client,
84 u8 number, u8 length, u8 *values)
86 int ret = i2c_smbus_read_i2c_block_data(client, number << 4, length,
89 return ret < 0 ? ret : -EIO;
94 static s32 rx8025_write_reg(const struct i2c_client *client, u8 number,
97 return i2c_smbus_write_byte_data(client, number << 4, value);
100 static s32 rx8025_write_regs(const struct i2c_client *client,
101 u8 number, u8 length, const u8 *values)
103 return i2c_smbus_write_i2c_block_data(client, number << 4,
107 static irqreturn_t rx8025_handle_irq(int irq, void *dev_id)
109 struct i2c_client *client = dev_id;
110 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
113 status = rx8025_read_reg(client, RX8025_REG_CTRL2);
117 if (!(status & RX8025_BIT_CTRL2_XST))
118 dev_warn(&client->dev, "Oscillation stop was detected,"
119 "you may have to readjust the clock\n");
121 if (status & RX8025_BIT_CTRL2_CTFG) {
123 status &= ~RX8025_BIT_CTRL2_CTFG;
124 rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF);
127 if (status & RX8025_BIT_CTRL2_DAFG) {
129 status &= RX8025_BIT_CTRL2_DAFG;
130 if (rx8025_write_reg(client, RX8025_REG_CTRL1,
131 rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
133 rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF);
136 /* acknowledge IRQ */
137 rx8025_write_reg(client, RX8025_REG_CTRL2,
138 status | RX8025_BIT_CTRL2_XST);
144 static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
146 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
150 ctrl = rx8025_read_reg(rx8025->client, RX8025_REG_CTRL2);
154 if (ctrl & RX8025_BIT_CTRL2_PON) {
155 dev_warn(dev, "power-on reset detected, date is invalid\n");
159 if (!(ctrl & RX8025_BIT_CTRL2_XST)) {
160 dev_warn(dev, "crystal stopped, date is invalid\n");
164 err = rx8025_read_regs(rx8025->client, RX8025_REG_SEC, 7, date);
168 dev_dbg(dev, "%s: read 0x%02x 0x%02x "
169 "0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n", __func__,
170 date[0], date[1], date[2], date[3], date[4],
173 dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
174 dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
175 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
176 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
178 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
179 + (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
181 dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
182 dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
183 dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]) + 100;
185 dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
186 dt->tm_sec, dt->tm_min, dt->tm_hour,
187 dt->tm_mday, dt->tm_mon, dt->tm_year);
189 return rtc_valid_tm(dt);
192 static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
194 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
197 if ((dt->tm_year < 100) || (dt->tm_year > 199))
201 * Here the read-only bits are written as "0". I'm not sure if that
204 date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
205 date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
206 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
207 date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
209 date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
210 | bin2bcd((dt->tm_hour + 11) % 12 + 1);
212 date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
213 date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
214 date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
215 date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year - 100);
218 "%s: write 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",
220 date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
222 return rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);
225 static int rx8025_init_client(struct i2c_client *client)
227 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
232 err = rx8025_read_regs(rx8025->client, RX8025_REG_CTRL1, 2, ctrl);
236 /* Keep test bit zero ! */
237 rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
239 if (ctrl[1] & RX8025_BIT_CTRL2_PON) {
240 dev_warn(&client->dev, "power-on reset was detected, "
241 "you may have to readjust the clock\n");
245 if (ctrl[1] & RX8025_BIT_CTRL2_VDET) {
246 dev_warn(&client->dev, "a power voltage drop was detected, "
247 "you may have to readjust the clock\n");
251 if (!(ctrl[1] & RX8025_BIT_CTRL2_XST)) {
252 dev_warn(&client->dev, "Oscillation stop was detected,"
253 "you may have to readjust the clock\n");
257 if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) {
258 dev_warn(&client->dev, "Alarm was detected\n");
262 if (!(ctrl[1] & RX8025_BIT_CTRL2_CTFG))
267 ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET |
268 RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
269 RX8025_BIT_CTRL2_DAFG);
270 ctrl2 |= RX8025_BIT_CTRL2_XST;
272 err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
279 static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)
281 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
282 struct i2c_client *client = rx8025->client;
286 if (client->irq <= 0)
289 err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
293 ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
297 dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
298 __func__, ald[0], ald[1], ctrl2);
300 /* Hardware alarms precision is 1 minute! */
302 t->time.tm_min = bcd2bin(ald[0] & 0x7f);
303 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
304 t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
306 t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
307 + (ald[1] & 0x20 ? 12 : 0);
309 t->time.tm_wday = -1;
310 t->time.tm_mday = -1;
312 t->time.tm_year = -1;
314 dev_dbg(dev, "%s: date: %ds %dm %dh %dmd %dm %dy\n",
316 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
317 t->time.tm_mday, t->time.tm_mon, t->time.tm_year);
318 t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
319 t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
324 static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)
326 struct i2c_client *client = to_i2c_client(dev);
327 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
331 if (client->irq <= 0)
334 /* Hardware alarm precision is 1 minute! */
335 ald[0] = bin2bcd(t->time.tm_min);
336 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
337 ald[1] = bin2bcd(t->time.tm_hour);
339 ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
340 | bin2bcd((t->time.tm_hour + 11) % 12 + 1);
342 dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
344 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
345 rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
346 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
351 err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald);
356 rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
357 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
366 static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
368 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
372 ctrl1 = rx8025->ctrl1;
374 ctrl1 |= RX8025_BIT_CTRL1_DALE;
376 ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
378 if (ctrl1 != rx8025->ctrl1) {
379 rx8025->ctrl1 = ctrl1;
380 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
388 static struct rtc_class_ops rx8025_rtc_ops = {
389 .read_time = rx8025_get_time,
390 .set_time = rx8025_set_time,
391 .read_alarm = rx8025_read_alarm,
392 .set_alarm = rx8025_set_alarm,
393 .alarm_irq_enable = rx8025_alarm_irq_enable,
397 * Clock precision adjustment support
399 * According to the RX8025 SA/NB application manual the frequency and
400 * temperature characteristics can be approximated using the following
403 * df = a * (ut - t)**2
405 * df: Frequency deviation in any temperature
406 * a : Coefficient = (-35 +-5) * 10**-9
407 * ut: Ultimate temperature in degree = +25 +-5 degree
408 * t : Any temperature in degree
410 * Note that the clock adjustment in ppb must be entered (which is
411 * the negative value of the deviation).
413 static int rx8025_get_clock_adjust(struct device *dev, int *adj)
415 struct i2c_client *client = to_i2c_client(dev);
418 digoff = rx8025_read_reg(client, RX8025_REG_DIGOFF);
422 *adj = digoff >= 64 ? digoff - 128 : digoff;
425 *adj *= -RX8025_ADJ_RESOLUTION;
430 static int rx8025_set_clock_adjust(struct device *dev, int adj)
432 struct i2c_client *client = to_i2c_client(dev);
436 adj /= -RX8025_ADJ_RESOLUTION;
437 if (adj > RX8025_ADJ_DATA_MAX)
438 adj = RX8025_ADJ_DATA_MAX;
439 else if (adj < RX8025_ADJ_DATA_MIN)
440 adj = RX8025_ADJ_DATA_MIN;
447 err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
451 dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
456 static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
457 struct device_attribute *attr,
462 err = rx8025_get_clock_adjust(dev, &adj);
466 return sprintf(buf, "%d\n", adj);
469 static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
470 struct device_attribute *attr,
471 const char *buf, size_t count)
475 if (sscanf(buf, "%i", &adj) != 1)
478 err = rx8025_set_clock_adjust(dev, adj);
480 return err ? err : count;
483 static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,
484 rx8025_sysfs_show_clock_adjust,
485 rx8025_sysfs_store_clock_adjust);
487 static int rx8025_sysfs_register(struct device *dev)
489 return device_create_file(dev, &dev_attr_clock_adjust_ppb);
492 static void rx8025_sysfs_unregister(struct device *dev)
494 device_remove_file(dev, &dev_attr_clock_adjust_ppb);
497 static int rx8025_probe(struct i2c_client *client,
498 const struct i2c_device_id *id)
500 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
501 struct rx8025_data *rx8025;
504 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
505 | I2C_FUNC_SMBUS_I2C_BLOCK)) {
506 dev_err(&adapter->dev,
507 "doesn't support required functionality\n");
511 rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
516 rx8025->client = client;
517 i2c_set_clientdata(client, rx8025);
519 err = rx8025_init_client(client);
523 rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
524 &rx8025_rtc_ops, THIS_MODULE);
525 if (IS_ERR(rx8025->rtc)) {
526 dev_err(&client->dev, "unable to register the class device\n");
527 return PTR_ERR(rx8025->rtc);
530 if (client->irq > 0) {
531 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
532 err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
533 rx8025_handle_irq, 0, "rx8025",
536 dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
541 rx8025->rtc->irq_freq = 1;
542 rx8025->rtc->max_user_freq = 1;
544 err = rx8025_sysfs_register(&client->dev);
548 static int rx8025_remove(struct i2c_client *client)
550 rx8025_sysfs_unregister(&client->dev);
554 static struct i2c_driver rx8025_driver = {
556 .name = "rtc-rx8025",
558 .probe = rx8025_probe,
559 .remove = rx8025_remove,
560 .id_table = rx8025_id,
563 module_i2c_driver(rx8025_driver);
565 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
566 MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
567 MODULE_LICENSE("GPL");