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/kernel.h>
22 #include <linux/module.h>
23 #include <linux/slab.h>
24 #include <linux/init.h>
25 #include <linux/bcd.h>
26 #include <linux/i2c.h>
27 #include <linux/list.h>
28 #include <linux/rtc.h>
30 /* Register definitions */
31 #define RX8025_REG_SEC 0x00
32 #define RX8025_REG_MIN 0x01
33 #define RX8025_REG_HOUR 0x02
34 #define RX8025_REG_WDAY 0x03
35 #define RX8025_REG_MDAY 0x04
36 #define RX8025_REG_MONTH 0x05
37 #define RX8025_REG_YEAR 0x06
38 #define RX8025_REG_DIGOFF 0x07
39 #define RX8025_REG_ALWMIN 0x08
40 #define RX8025_REG_ALWHOUR 0x09
41 #define RX8025_REG_ALWWDAY 0x0a
42 #define RX8025_REG_ALDMIN 0x0b
43 #define RX8025_REG_ALDHOUR 0x0c
44 /* 0x0d is reserved */
45 #define RX8025_REG_CTRL1 0x0e
46 #define RX8025_REG_CTRL2 0x0f
48 #define RX8025_BIT_CTRL1_CT (7 << 0)
49 /* 1 Hz periodic level irq */
50 #define RX8025_BIT_CTRL1_CT_1HZ 4
51 #define RX8025_BIT_CTRL1_TEST (1 << 3)
52 #define RX8025_BIT_CTRL1_1224 (1 << 5)
53 #define RX8025_BIT_CTRL1_DALE (1 << 6)
54 #define RX8025_BIT_CTRL1_WALE (1 << 7)
56 #define RX8025_BIT_CTRL2_DAFG (1 << 0)
57 #define RX8025_BIT_CTRL2_WAFG (1 << 1)
58 #define RX8025_BIT_CTRL2_CTFG (1 << 2)
59 #define RX8025_BIT_CTRL2_PON (1 << 4)
60 #define RX8025_BIT_CTRL2_XST (1 << 5)
61 #define RX8025_BIT_CTRL2_VDET (1 << 6)
63 /* Clock precision adjustment */
64 #define RX8025_ADJ_RESOLUTION 3050 /* in ppb */
65 #define RX8025_ADJ_DATA_MAX 62
66 #define RX8025_ADJ_DATA_MIN -62
68 static const struct i2c_device_id rx8025_id[] = {
72 MODULE_DEVICE_TABLE(i2c, rx8025_id);
75 struct i2c_client *client;
76 struct rtc_device *rtc;
77 struct work_struct work;
82 static int rx8025_read_reg(struct i2c_client *client, int number, u8 *value)
84 int ret = i2c_smbus_read_byte_data(client, (number << 4) | 0x08);
87 dev_err(&client->dev, "Unable to read register #%d\n", number);
95 static int rx8025_read_regs(struct i2c_client *client,
96 int number, u8 length, u8 *values)
98 int ret = i2c_smbus_read_i2c_block_data(client, (number << 4) | 0x08,
102 dev_err(&client->dev, "Unable to read registers #%d..#%d\n",
103 number, number + length - 1);
104 return ret < 0 ? ret : -EIO;
110 static int rx8025_write_reg(struct i2c_client *client, int number, u8 value)
112 int ret = i2c_smbus_write_byte_data(client, number << 4, value);
115 dev_err(&client->dev, "Unable to write register #%d\n",
121 static int rx8025_write_regs(struct i2c_client *client,
122 int number, u8 length, u8 *values)
124 int ret = i2c_smbus_write_i2c_block_data(client, (number << 4) | 0x08,
128 dev_err(&client->dev, "Unable to write registers #%d..#%d\n",
129 number, number + length - 1);
134 static irqreturn_t rx8025_irq(int irq, void *dev_id)
136 struct i2c_client *client = dev_id;
137 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
139 disable_irq_nosync(irq);
140 schedule_work(&rx8025->work);
144 static void rx8025_work(struct work_struct *work)
146 struct rx8025_data *rx8025 = container_of(work, struct rx8025_data,
148 struct i2c_client *client = rx8025->client;
149 struct mutex *lock = &rx8025->rtc->ops_lock;
154 if (rx8025_read_reg(client, RX8025_REG_CTRL2, &status))
157 if (!(status & RX8025_BIT_CTRL2_XST))
158 dev_warn(&client->dev, "Oscillation stop was detected,"
159 "you may have to readjust the clock\n");
161 if (status & RX8025_BIT_CTRL2_CTFG) {
163 status &= ~RX8025_BIT_CTRL2_CTFG;
164 rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF);
167 if (status & RX8025_BIT_CTRL2_DAFG) {
169 status &= RX8025_BIT_CTRL2_DAFG;
170 if (rx8025_write_reg(client, RX8025_REG_CTRL1,
171 rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
173 rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF);
176 /* acknowledge IRQ */
177 rx8025_write_reg(client, RX8025_REG_CTRL2,
178 status | RX8025_BIT_CTRL2_XST);
181 if (!rx8025->exiting)
182 enable_irq(client->irq);
187 static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
189 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
193 err = rx8025_read_regs(rx8025->client, RX8025_REG_SEC, 7, date);
197 dev_dbg(dev, "%s: read 0x%02x 0x%02x "
198 "0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n", __func__,
199 date[0], date[1], date[2], date[3], date[4],
202 dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
203 dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
204 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
205 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
207 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
208 + (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
210 dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
211 dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
212 dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]);
214 if (dt->tm_year < 70)
217 dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
218 dt->tm_sec, dt->tm_min, dt->tm_hour,
219 dt->tm_mday, dt->tm_mon, dt->tm_year);
221 return rtc_valid_tm(dt);
224 static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
226 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
230 * BUG: The HW assumes every year that is a multiple of 4 to be a leap
231 * year. Next time this is wrong is 2100, which will not be a leap
236 * Here the read-only bits are written as "0". I'm not sure if that
239 date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
240 date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
241 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
242 date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
244 date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
245 | bin2bcd((dt->tm_hour + 11) % 12 + 1);
247 date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
248 date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
249 date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
250 date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year % 100);
253 "%s: write 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",
255 date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
257 return rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);
260 static int rx8025_init_client(struct i2c_client *client, int *need_reset)
262 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
267 err = rx8025_read_regs(rx8025->client, RX8025_REG_CTRL1, 2, ctrl);
271 /* Keep test bit zero ! */
272 rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
274 if (ctrl[1] & RX8025_BIT_CTRL2_PON) {
275 dev_warn(&client->dev, "power-on reset was detected, "
276 "you may have to readjust the clock\n");
280 if (ctrl[1] & RX8025_BIT_CTRL2_VDET) {
281 dev_warn(&client->dev, "a power voltage drop was detected, "
282 "you may have to readjust the clock\n");
286 if (!(ctrl[1] & RX8025_BIT_CTRL2_XST)) {
287 dev_warn(&client->dev, "Oscillation stop was detected,"
288 "you may have to readjust the clock\n");
292 if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) {
293 dev_warn(&client->dev, "Alarm was detected\n");
297 if (!(ctrl[1] & RX8025_BIT_CTRL2_CTFG))
300 if (*need_reset || need_clear) {
302 ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET |
303 RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
304 RX8025_BIT_CTRL2_DAFG);
305 ctrl2 |= RX8025_BIT_CTRL2_XST;
307 err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
314 static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)
316 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
317 struct i2c_client *client = rx8025->client;
321 if (client->irq <= 0)
324 err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
328 err = rx8025_read_reg(client, RX8025_REG_CTRL2, &ctrl2);
332 dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
333 __func__, ald[0], ald[1], ctrl2);
335 /* Hardware alarms precision is 1 minute! */
337 t->time.tm_min = bcd2bin(ald[0] & 0x7f);
338 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
339 t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
341 t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
342 + (ald[1] & 0x20 ? 12 : 0);
344 t->time.tm_wday = -1;
345 t->time.tm_mday = -1;
347 t->time.tm_year = -1;
349 dev_dbg(dev, "%s: date: %ds %dm %dh %dmd %dm %dy\n",
351 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
352 t->time.tm_mday, t->time.tm_mon, t->time.tm_year);
353 t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
354 t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
359 static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)
361 struct i2c_client *client = to_i2c_client(dev);
362 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
366 if (client->irq <= 0)
369 /* Hardware alarm precision is 1 minute! */
370 ald[0] = bin2bcd(t->time.tm_min);
371 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
372 ald[1] = bin2bcd(t->time.tm_hour);
374 ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
375 | bin2bcd((t->time.tm_hour + 11) % 12 + 1);
377 dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
379 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
380 rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
381 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
386 err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald);
391 rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
392 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
401 static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
403 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
407 ctrl1 = rx8025->ctrl1;
409 ctrl1 |= RX8025_BIT_CTRL1_DALE;
411 ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
413 if (ctrl1 != rx8025->ctrl1) {
414 rx8025->ctrl1 = ctrl1;
415 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
423 static struct rtc_class_ops rx8025_rtc_ops = {
424 .read_time = rx8025_get_time,
425 .set_time = rx8025_set_time,
426 .read_alarm = rx8025_read_alarm,
427 .set_alarm = rx8025_set_alarm,
428 .alarm_irq_enable = rx8025_alarm_irq_enable,
432 * Clock precision adjustment support
434 * According to the RX8025 SA/NB application manual the frequency and
435 * temperature characteristics can be approximated using the following
438 * df = a * (ut - t)**2
440 * df: Frequency deviation in any temperature
441 * a : Coefficient = (-35 +-5) * 10**-9
442 * ut: Ultimate temperature in degree = +25 +-5 degree
443 * t : Any temperature in degree
445 * Note that the clock adjustment in ppb must be entered (which is
446 * the negative value of the deviation).
448 static int rx8025_get_clock_adjust(struct device *dev, int *adj)
450 struct i2c_client *client = to_i2c_client(dev);
454 err = rx8025_read_reg(client, RX8025_REG_DIGOFF, &digoff);
458 *adj = digoff >= 64 ? digoff - 128 : digoff;
461 *adj *= -RX8025_ADJ_RESOLUTION;
466 static int rx8025_set_clock_adjust(struct device *dev, int adj)
468 struct i2c_client *client = to_i2c_client(dev);
472 adj /= -RX8025_ADJ_RESOLUTION;
473 if (adj > RX8025_ADJ_DATA_MAX)
474 adj = RX8025_ADJ_DATA_MAX;
475 else if (adj < RX8025_ADJ_DATA_MIN)
476 adj = RX8025_ADJ_DATA_MIN;
483 err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
487 dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
492 static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
493 struct device_attribute *attr,
498 err = rx8025_get_clock_adjust(dev, &adj);
502 return sprintf(buf, "%d\n", adj);
505 static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
506 struct device_attribute *attr,
507 const char *buf, size_t count)
511 if (sscanf(buf, "%i", &adj) != 1)
514 err = rx8025_set_clock_adjust(dev, adj);
516 return err ? err : count;
519 static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,
520 rx8025_sysfs_show_clock_adjust,
521 rx8025_sysfs_store_clock_adjust);
523 static int rx8025_sysfs_register(struct device *dev)
525 return device_create_file(dev, &dev_attr_clock_adjust_ppb);
528 static void rx8025_sysfs_unregister(struct device *dev)
530 device_remove_file(dev, &dev_attr_clock_adjust_ppb);
533 static int rx8025_probe(struct i2c_client *client,
534 const struct i2c_device_id *id)
536 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
537 struct rx8025_data *rx8025;
538 int err, need_reset = 0;
540 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
541 | I2C_FUNC_SMBUS_I2C_BLOCK)) {
542 dev_err(&adapter->dev,
543 "doesn't support required functionality\n");
548 rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
554 rx8025->client = client;
555 i2c_set_clientdata(client, rx8025);
556 INIT_WORK(&rx8025->work, rx8025_work);
558 err = rx8025_init_client(client, &need_reset);
564 dev_info(&client->dev,
565 "bad conditions detected, resetting date\n");
566 rtc_time_to_tm(0, &tm); /* 1970/1/1 */
567 rx8025_set_time(&client->dev, &tm);
570 rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
571 &rx8025_rtc_ops, THIS_MODULE);
572 if (IS_ERR(rx8025->rtc)) {
573 err = PTR_ERR(rx8025->rtc);
574 dev_err(&client->dev, "unable to register the class device\n");
578 if (client->irq > 0) {
579 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
580 err = request_irq(client->irq, rx8025_irq,
581 0, "rx8025", client);
583 dev_err(&client->dev, "unable to request IRQ\n");
588 rx8025->rtc->irq_freq = 1;
589 rx8025->rtc->max_user_freq = 1;
591 err = rx8025_sysfs_register(&client->dev);
599 free_irq(client->irq, client);
602 dev_err(&adapter->dev, "probing for rx8025 failed\n");
606 static int rx8025_remove(struct i2c_client *client)
608 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
609 struct mutex *lock = &rx8025->rtc->ops_lock;
611 if (client->irq > 0) {
616 free_irq(client->irq, client);
617 cancel_work_sync(&rx8025->work);
620 rx8025_sysfs_unregister(&client->dev);
624 static struct i2c_driver rx8025_driver = {
626 .name = "rtc-rx8025",
628 .probe = rx8025_probe,
629 .remove = rx8025_remove,
630 .id_table = rx8025_id,
633 module_i2c_driver(rx8025_driver);
635 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
636 MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
637 MODULE_LICENSE("GPL");