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[] = {
71 MODULE_DEVICE_TABLE(i2c, rx8025_id);
74 struct i2c_client *client;
75 struct rtc_device *rtc;
79 static s32 rx8025_read_reg(const struct i2c_client *client, u8 number)
81 return i2c_smbus_read_byte_data(client, number << 4);
84 static int rx8025_read_regs(const struct i2c_client *client,
85 u8 number, u8 length, u8 *values)
87 int ret = i2c_smbus_read_i2c_block_data(client, number << 4, length,
90 return ret < 0 ? ret : -EIO;
95 static s32 rx8025_write_reg(const struct i2c_client *client, u8 number,
98 return i2c_smbus_write_byte_data(client, number << 4, value);
101 static s32 rx8025_write_regs(const struct i2c_client *client,
102 u8 number, u8 length, const u8 *values)
104 return i2c_smbus_write_i2c_block_data(client, number << 4,
108 static int rx8025_check_validity(struct device *dev)
110 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
113 ctrl2 = rx8025_read_reg(rx8025->client, RX8025_REG_CTRL2);
117 if (ctrl2 & RX8025_BIT_CTRL2_VDET)
118 dev_warn(dev, "power voltage drop detected\n");
120 if (ctrl2 & RX8025_BIT_CTRL2_PON) {
121 dev_warn(dev, "power-on reset detected, date is invalid\n");
125 if (!(ctrl2 & RX8025_BIT_CTRL2_XST)) {
126 dev_warn(dev, "crystal stopped, date is invalid\n");
133 static int rx8025_reset_validity(struct i2c_client *client)
135 int ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
140 ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET);
142 return rx8025_write_reg(client, RX8025_REG_CTRL2,
143 ctrl2 | RX8025_BIT_CTRL2_XST);
146 static irqreturn_t rx8025_handle_irq(int irq, void *dev_id)
148 struct i2c_client *client = dev_id;
149 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
152 status = rx8025_read_reg(client, RX8025_REG_CTRL2);
156 if (!(status & RX8025_BIT_CTRL2_XST))
157 dev_warn(&client->dev, "Oscillation stop was detected,"
158 "you may have to readjust the clock\n");
160 if (status & RX8025_BIT_CTRL2_CTFG) {
162 status &= ~RX8025_BIT_CTRL2_CTFG;
163 rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF);
166 if (status & RX8025_BIT_CTRL2_DAFG) {
168 status &= RX8025_BIT_CTRL2_DAFG;
169 if (rx8025_write_reg(client, RX8025_REG_CTRL1,
170 rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
172 rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF);
179 static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
181 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
185 err = rx8025_check_validity(dev);
189 err = rx8025_read_regs(rx8025->client, RX8025_REG_SEC, 7, date);
193 dev_dbg(dev, "%s: read 0x%02x 0x%02x "
194 "0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n", __func__,
195 date[0], date[1], date[2], date[3], date[4],
198 dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
199 dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
200 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
201 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
203 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
204 + (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
206 dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
207 dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
208 dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]) + 100;
210 dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
211 dt->tm_sec, dt->tm_min, dt->tm_hour,
212 dt->tm_mday, dt->tm_mon, dt->tm_year);
214 return rtc_valid_tm(dt);
217 static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
219 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
223 if ((dt->tm_year < 100) || (dt->tm_year > 199))
227 * Here the read-only bits are written as "0". I'm not sure if that
230 date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
231 date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
232 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
233 date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
235 date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
236 | bin2bcd((dt->tm_hour + 11) % 12 + 1);
238 date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
239 date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
240 date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
241 date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year - 100);
244 "%s: write 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",
246 date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
248 ret = rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);
252 return rx8025_reset_validity(rx8025->client);
255 static int rx8025_init_client(struct i2c_client *client)
257 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
262 err = rx8025_read_regs(rx8025->client, RX8025_REG_CTRL1, 2, ctrl);
266 /* Keep test bit zero ! */
267 rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
269 if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) {
270 dev_warn(&client->dev, "Alarm was detected\n");
274 if (ctrl[1] & RX8025_BIT_CTRL2_CTFG)
279 ctrl2 &= ~(RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
280 RX8025_BIT_CTRL2_DAFG);
282 err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
289 static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)
291 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
292 struct i2c_client *client = rx8025->client;
296 if (client->irq <= 0)
299 err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
303 ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
307 dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
308 __func__, ald[0], ald[1], ctrl2);
310 /* Hardware alarms precision is 1 minute! */
312 t->time.tm_min = bcd2bin(ald[0] & 0x7f);
313 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
314 t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
316 t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
317 + (ald[1] & 0x20 ? 12 : 0);
319 t->time.tm_wday = -1;
320 t->time.tm_mday = -1;
322 t->time.tm_year = -1;
324 dev_dbg(dev, "%s: date: %ds %dm %dh %dmd %dm %dy\n",
326 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
327 t->time.tm_mday, t->time.tm_mon, t->time.tm_year);
328 t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
329 t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
334 static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)
336 struct i2c_client *client = to_i2c_client(dev);
337 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
341 if (client->irq <= 0)
344 /* Hardware alarm precision is 1 minute! */
345 ald[0] = bin2bcd(t->time.tm_min);
346 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
347 ald[1] = bin2bcd(t->time.tm_hour);
349 ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
350 | bin2bcd((t->time.tm_hour + 11) % 12 + 1);
352 dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
354 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
355 rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
356 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
361 err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald);
366 rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
367 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
376 static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
378 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
382 ctrl1 = rx8025->ctrl1;
384 ctrl1 |= RX8025_BIT_CTRL1_DALE;
386 ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
388 if (ctrl1 != rx8025->ctrl1) {
389 rx8025->ctrl1 = ctrl1;
390 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
398 static struct rtc_class_ops rx8025_rtc_ops = {
399 .read_time = rx8025_get_time,
400 .set_time = rx8025_set_time,
401 .read_alarm = rx8025_read_alarm,
402 .set_alarm = rx8025_set_alarm,
403 .alarm_irq_enable = rx8025_alarm_irq_enable,
407 * Clock precision adjustment support
409 * According to the RX8025 SA/NB application manual the frequency and
410 * temperature characteristics can be approximated using the following
413 * df = a * (ut - t)**2
415 * df: Frequency deviation in any temperature
416 * a : Coefficient = (-35 +-5) * 10**-9
417 * ut: Ultimate temperature in degree = +25 +-5 degree
418 * t : Any temperature in degree
420 * Note that the clock adjustment in ppb must be entered (which is
421 * the negative value of the deviation).
423 static int rx8025_get_clock_adjust(struct device *dev, int *adj)
425 struct i2c_client *client = to_i2c_client(dev);
428 digoff = rx8025_read_reg(client, RX8025_REG_DIGOFF);
432 *adj = digoff >= 64 ? digoff - 128 : digoff;
435 *adj *= -RX8025_ADJ_RESOLUTION;
440 static int rx8025_set_clock_adjust(struct device *dev, int adj)
442 struct i2c_client *client = to_i2c_client(dev);
446 adj /= -RX8025_ADJ_RESOLUTION;
447 if (adj > RX8025_ADJ_DATA_MAX)
448 adj = RX8025_ADJ_DATA_MAX;
449 else if (adj < RX8025_ADJ_DATA_MIN)
450 adj = RX8025_ADJ_DATA_MIN;
457 err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
461 dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
466 static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
467 struct device_attribute *attr,
472 err = rx8025_get_clock_adjust(dev, &adj);
476 return sprintf(buf, "%d\n", adj);
479 static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
480 struct device_attribute *attr,
481 const char *buf, size_t count)
485 if (sscanf(buf, "%i", &adj) != 1)
488 err = rx8025_set_clock_adjust(dev, adj);
490 return err ? err : count;
493 static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,
494 rx8025_sysfs_show_clock_adjust,
495 rx8025_sysfs_store_clock_adjust);
497 static int rx8025_sysfs_register(struct device *dev)
499 return device_create_file(dev, &dev_attr_clock_adjust_ppb);
502 static void rx8025_sysfs_unregister(struct device *dev)
504 device_remove_file(dev, &dev_attr_clock_adjust_ppb);
507 static int rx8025_probe(struct i2c_client *client,
508 const struct i2c_device_id *id)
510 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
511 struct rx8025_data *rx8025;
514 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
515 | I2C_FUNC_SMBUS_I2C_BLOCK)) {
516 dev_err(&adapter->dev,
517 "doesn't support required functionality\n");
521 rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
525 rx8025->client = client;
526 i2c_set_clientdata(client, rx8025);
528 err = rx8025_init_client(client);
532 rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
533 &rx8025_rtc_ops, THIS_MODULE);
534 if (IS_ERR(rx8025->rtc)) {
535 dev_err(&client->dev, "unable to register the class device\n");
536 return PTR_ERR(rx8025->rtc);
539 if (client->irq > 0) {
540 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
541 err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
542 rx8025_handle_irq, 0, "rx8025",
545 dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
550 rx8025->rtc->max_user_freq = 1;
552 err = rx8025_sysfs_register(&client->dev);
556 static int rx8025_remove(struct i2c_client *client)
558 rx8025_sysfs_unregister(&client->dev);
562 static struct i2c_driver rx8025_driver = {
564 .name = "rtc-rx8025",
566 .probe = rx8025_probe,
567 .remove = rx8025_remove,
568 .id_table = rx8025_id,
571 module_i2c_driver(rx8025_driver);
573 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
574 MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
575 MODULE_LICENSE("GPL");