2 * I2C client/driver for the ST M41T80 family of i2c rtc chips.
4 * Author: Alexander Bigga <ab@mycable.de>
6 * Based on m41t00.c by Mark A. Greer <mgreer@mvista.com>
8 * 2006 (c) mycable GmbH
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 #include <linux/bcd.h>
19 #include <linux/i2c.h>
20 #include <linux/init.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/of_device.h>
24 #include <linux/rtc.h>
25 #include <linux/slab.h>
26 #include <linux/mutex.h>
27 #include <linux/string.h>
28 #ifdef CONFIG_RTC_DRV_M41T80_WDT
30 #include <linux/ioctl.h>
31 #include <linux/miscdevice.h>
32 #include <linux/reboot.h>
33 #include <linux/watchdog.h>
36 #define M41T80_REG_SSEC 0x00
37 #define M41T80_REG_SEC 0x01
38 #define M41T80_REG_MIN 0x02
39 #define M41T80_REG_HOUR 0x03
40 #define M41T80_REG_WDAY 0x04
41 #define M41T80_REG_DAY 0x05
42 #define M41T80_REG_MON 0x06
43 #define M41T80_REG_YEAR 0x07
44 #define M41T80_REG_ALARM_MON 0x0a
45 #define M41T80_REG_ALARM_DAY 0x0b
46 #define M41T80_REG_ALARM_HOUR 0x0c
47 #define M41T80_REG_ALARM_MIN 0x0d
48 #define M41T80_REG_ALARM_SEC 0x0e
49 #define M41T80_REG_FLAGS 0x0f
50 #define M41T80_REG_SQW 0x13
52 #define M41T80_DATETIME_REG_SIZE (M41T80_REG_YEAR + 1)
53 #define M41T80_ALARM_REG_SIZE \
54 (M41T80_REG_ALARM_SEC + 1 - M41T80_REG_ALARM_MON)
56 #define M41T80_SEC_ST BIT(7) /* ST: Stop Bit */
57 #define M41T80_ALMON_AFE BIT(7) /* AFE: AF Enable Bit */
58 #define M41T80_ALMON_SQWE BIT(6) /* SQWE: SQW Enable Bit */
59 #define M41T80_ALHOUR_HT BIT(6) /* HT: Halt Update Bit */
60 #define M41T80_FLAGS_OF BIT(2) /* OF: Oscillator Failure Bit */
61 #define M41T80_FLAGS_AF BIT(6) /* AF: Alarm Flag Bit */
62 #define M41T80_FLAGS_BATT_LOW BIT(4) /* BL: Battery Low Bit */
63 #define M41T80_WATCHDOG_RB2 BIT(7) /* RB: Watchdog resolution */
64 #define M41T80_WATCHDOG_RB1 BIT(1) /* RB: Watchdog resolution */
65 #define M41T80_WATCHDOG_RB0 BIT(0) /* RB: Watchdog resolution */
67 #define M41T80_FEATURE_HT BIT(0) /* Halt feature */
68 #define M41T80_FEATURE_BL BIT(1) /* Battery low indicator */
69 #define M41T80_FEATURE_SQ BIT(2) /* Squarewave feature */
70 #define M41T80_FEATURE_WD BIT(3) /* Extra watchdog resolution */
71 #define M41T80_FEATURE_SQ_ALT BIT(4) /* RSx bits are in reg 4 */
73 static DEFINE_MUTEX(m41t80_rtc_mutex);
74 static const struct i2c_device_id m41t80_id[] = {
75 { "m41t62", M41T80_FEATURE_SQ | M41T80_FEATURE_SQ_ALT },
76 { "m41t65", M41T80_FEATURE_HT | M41T80_FEATURE_WD },
77 { "m41t80", M41T80_FEATURE_SQ },
78 { "m41t81", M41T80_FEATURE_HT | M41T80_FEATURE_SQ},
79 { "m41t81s", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
80 { "m41t82", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
81 { "m41t83", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
82 { "m41st84", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
83 { "m41st85", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
84 { "m41st87", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
85 { "rv4162", M41T80_FEATURE_SQ | M41T80_FEATURE_WD | M41T80_FEATURE_SQ_ALT },
88 MODULE_DEVICE_TABLE(i2c, m41t80_id);
90 static const struct of_device_id m41t80_of_match[] = {
92 .compatible = "st,m41t62",
93 .data = (void *)(M41T80_FEATURE_SQ | M41T80_FEATURE_SQ_ALT)
96 .compatible = "st,m41t65",
97 .data = (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_WD)
100 .compatible = "st,m41t80",
101 .data = (void *)(M41T80_FEATURE_SQ)
104 .compatible = "st,m41t81",
105 .data = (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_SQ)
108 .compatible = "st,m41t81s",
109 .data = (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ)
112 .compatible = "st,m41t82",
113 .data = (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ)
116 .compatible = "st,m41t83",
117 .data = (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ)
120 .compatible = "st,m41t84",
121 .data = (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ)
124 .compatible = "st,m41t85",
125 .data = (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ)
128 .compatible = "st,m41t87",
129 .data = (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ)
132 .compatible = "microcrystal,rv4162",
133 .data = (void *)(M41T80_FEATURE_SQ | M41T80_FEATURE_WD | M41T80_FEATURE_SQ_ALT)
135 /* DT compatibility only, do not use compatibles below: */
137 .compatible = "st,rv4162",
138 .data = (void *)(M41T80_FEATURE_SQ | M41T80_FEATURE_WD | M41T80_FEATURE_SQ_ALT)
141 .compatible = "rv4162",
142 .data = (void *)(M41T80_FEATURE_SQ | M41T80_FEATURE_WD | M41T80_FEATURE_SQ_ALT)
146 MODULE_DEVICE_TABLE(of, m41t80_of_match);
149 unsigned long features;
150 struct rtc_device *rtc;
153 static irqreturn_t m41t80_handle_irq(int irq, void *dev_id)
155 struct i2c_client *client = dev_id;
156 struct m41t80_data *m41t80 = i2c_get_clientdata(client);
157 struct mutex *lock = &m41t80->rtc->ops_lock;
158 unsigned long events = 0;
159 int flags, flags_afe;
163 flags_afe = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
169 flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
175 if (flags & M41T80_FLAGS_AF) {
176 flags &= ~M41T80_FLAGS_AF;
177 flags_afe &= ~M41T80_ALMON_AFE;
182 rtc_update_irq(m41t80->rtc, 1, events);
183 i2c_smbus_write_byte_data(client, M41T80_REG_FLAGS, flags);
184 i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
193 static int m41t80_get_datetime(struct i2c_client *client,
196 unsigned char buf[8];
199 flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
203 if (flags & M41T80_FLAGS_OF) {
204 dev_err(&client->dev, "Oscillator failure, data is invalid.\n");
208 err = i2c_smbus_read_i2c_block_data(client, M41T80_REG_SSEC,
211 dev_err(&client->dev, "Unable to read date\n");
215 tm->tm_sec = bcd2bin(buf[M41T80_REG_SEC] & 0x7f);
216 tm->tm_min = bcd2bin(buf[M41T80_REG_MIN] & 0x7f);
217 tm->tm_hour = bcd2bin(buf[M41T80_REG_HOUR] & 0x3f);
218 tm->tm_mday = bcd2bin(buf[M41T80_REG_DAY] & 0x3f);
219 tm->tm_wday = buf[M41T80_REG_WDAY] & 0x07;
220 tm->tm_mon = bcd2bin(buf[M41T80_REG_MON] & 0x1f) - 1;
222 /* assume 20YY not 19YY, and ignore the Century Bit */
223 tm->tm_year = bcd2bin(buf[M41T80_REG_YEAR]) + 100;
224 return rtc_valid_tm(tm);
227 /* Sets the given date and time to the real time clock. */
228 static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm)
230 unsigned char buf[8];
233 if (tm->tm_year < 100 || tm->tm_year > 199)
236 buf[M41T80_REG_SSEC] = 0;
237 buf[M41T80_REG_SEC] = bin2bcd(tm->tm_sec);
238 buf[M41T80_REG_MIN] = bin2bcd(tm->tm_min);
239 buf[M41T80_REG_HOUR] = bin2bcd(tm->tm_hour);
240 buf[M41T80_REG_DAY] = bin2bcd(tm->tm_mday);
241 buf[M41T80_REG_MON] = bin2bcd(tm->tm_mon + 1);
242 buf[M41T80_REG_YEAR] = bin2bcd(tm->tm_year - 100);
243 buf[M41T80_REG_WDAY] = tm->tm_wday;
245 err = i2c_smbus_write_i2c_block_data(client, M41T80_REG_SSEC,
248 dev_err(&client->dev, "Unable to write to date registers\n");
252 /* Clear the OF bit of Flags Register */
253 flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
257 if (i2c_smbus_write_byte_data(client, M41T80_REG_FLAGS,
258 flags & ~M41T80_FLAGS_OF)) {
259 dev_err(&client->dev, "Unable to write flags register\n");
266 static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq)
268 struct i2c_client *client = to_i2c_client(dev);
269 struct m41t80_data *clientdata = i2c_get_clientdata(client);
272 if (clientdata->features & M41T80_FEATURE_BL) {
273 reg = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
274 seq_printf(seq, "battery\t\t: %s\n",
275 (reg & M41T80_FLAGS_BATT_LOW) ? "exhausted" : "ok");
280 static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm)
282 return m41t80_get_datetime(to_i2c_client(dev), tm);
285 static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm)
287 return m41t80_set_datetime(to_i2c_client(dev), tm);
290 static int m41t80_alarm_irq_enable(struct device *dev, unsigned int enabled)
292 struct i2c_client *client = to_i2c_client(dev);
295 flags = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
300 flags |= M41T80_ALMON_AFE;
302 flags &= ~M41T80_ALMON_AFE;
304 retval = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, flags);
306 dev_err(dev, "Unable to enable alarm IRQ %d\n", retval);
312 static int m41t80_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
314 struct i2c_client *client = to_i2c_client(dev);
318 alarmvals[0] = bin2bcd(alrm->time.tm_mon + 1);
319 alarmvals[1] = bin2bcd(alrm->time.tm_mday);
320 alarmvals[2] = bin2bcd(alrm->time.tm_hour);
321 alarmvals[3] = bin2bcd(alrm->time.tm_min);
322 alarmvals[4] = bin2bcd(alrm->time.tm_sec);
324 /* Clear AF and AFE flags */
325 ret = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
328 err = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
329 ret & ~(M41T80_ALMON_AFE));
331 dev_err(dev, "Unable to clear AFE bit\n");
335 /* Keep SQWE bit value */
336 alarmvals[0] |= (ret & M41T80_ALMON_SQWE);
338 ret = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
342 err = i2c_smbus_write_byte_data(client, M41T80_REG_FLAGS,
343 ret & ~(M41T80_FLAGS_AF));
345 dev_err(dev, "Unable to clear AF bit\n");
349 /* Write the alarm */
350 err = i2c_smbus_write_i2c_block_data(client, M41T80_REG_ALARM_MON,
355 /* Enable the alarm interrupt */
357 alarmvals[0] |= M41T80_ALMON_AFE;
358 err = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
367 static int m41t80_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
369 struct i2c_client *client = to_i2c_client(dev);
373 ret = i2c_smbus_read_i2c_block_data(client, M41T80_REG_ALARM_MON,
376 return ret < 0 ? ret : -EIO;
378 flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
382 alrm->time.tm_sec = bcd2bin(alarmvals[4] & 0x7f);
383 alrm->time.tm_min = bcd2bin(alarmvals[3] & 0x7f);
384 alrm->time.tm_hour = bcd2bin(alarmvals[2] & 0x3f);
385 alrm->time.tm_mday = bcd2bin(alarmvals[1] & 0x3f);
386 alrm->time.tm_mon = bcd2bin(alarmvals[0] & 0x3f);
388 alrm->enabled = !!(alarmvals[0] & M41T80_ALMON_AFE);
389 alrm->pending = (flags & M41T80_FLAGS_AF) && alrm->enabled;
394 static struct rtc_class_ops m41t80_rtc_ops = {
395 .read_time = m41t80_rtc_read_time,
396 .set_time = m41t80_rtc_set_time,
397 .proc = m41t80_rtc_proc,
400 #ifdef CONFIG_PM_SLEEP
401 static int m41t80_suspend(struct device *dev)
403 struct i2c_client *client = to_i2c_client(dev);
405 if (client->irq >= 0 && device_may_wakeup(dev))
406 enable_irq_wake(client->irq);
411 static int m41t80_resume(struct device *dev)
413 struct i2c_client *client = to_i2c_client(dev);
415 if (client->irq >= 0 && device_may_wakeup(dev))
416 disable_irq_wake(client->irq);
422 static SIMPLE_DEV_PM_OPS(m41t80_pm, m41t80_suspend, m41t80_resume);
424 static ssize_t flags_show(struct device *dev,
425 struct device_attribute *attr, char *buf)
427 struct i2c_client *client = to_i2c_client(dev);
430 val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
433 return sprintf(buf, "%#x\n", val);
435 static DEVICE_ATTR_RO(flags);
437 static ssize_t sqwfreq_show(struct device *dev,
438 struct device_attribute *attr, char *buf)
440 struct i2c_client *client = to_i2c_client(dev);
441 struct m41t80_data *clientdata = i2c_get_clientdata(client);
444 if (!(clientdata->features & M41T80_FEATURE_SQ))
447 reg_sqw = M41T80_REG_SQW;
448 if (clientdata->features & M41T80_FEATURE_SQ_ALT)
449 reg_sqw = M41T80_REG_WDAY;
450 val = i2c_smbus_read_byte_data(client, reg_sqw);
453 val = (val >> 4) & 0xf;
463 return sprintf(buf, "%d\n", val);
466 static ssize_t sqwfreq_store(struct device *dev,
467 struct device_attribute *attr,
468 const char *buf, size_t count)
470 struct i2c_client *client = to_i2c_client(dev);
471 struct m41t80_data *clientdata = i2c_get_clientdata(client);
472 int almon, sqw, reg_sqw, rc;
475 rc = kstrtoul(buf, 0, &val);
479 if (!(clientdata->features & M41T80_FEATURE_SQ))
483 if (!is_power_of_2(val))
493 /* disable SQW, set SQW frequency & re-enable */
494 almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
497 reg_sqw = M41T80_REG_SQW;
498 if (clientdata->features & M41T80_FEATURE_SQ_ALT)
499 reg_sqw = M41T80_REG_WDAY;
500 sqw = i2c_smbus_read_byte_data(client, reg_sqw);
503 sqw = (sqw & 0x0f) | (val << 4);
505 rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
506 almon & ~M41T80_ALMON_SQWE);
511 rc = i2c_smbus_write_byte_data(client, reg_sqw, sqw);
515 rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
516 almon | M41T80_ALMON_SQWE);
522 static DEVICE_ATTR_RW(sqwfreq);
524 static struct attribute *attrs[] = {
525 &dev_attr_flags.attr,
526 &dev_attr_sqwfreq.attr,
530 static struct attribute_group attr_group = {
534 #ifdef CONFIG_RTC_DRV_M41T80_WDT
536 *****************************************************************************
540 *****************************************************************************
542 static struct i2c_client *save_client;
545 #define WD_TIMO 60 /* 1..31 seconds */
547 static int wdt_margin = WD_TIMO;
548 module_param(wdt_margin, int, 0);
549 MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)");
551 static unsigned long wdt_is_open;
552 static int boot_flag;
557 * Reload counter one with the watchdog timeout. We don't bother reloading
558 * the cascade counter.
560 static void wdt_ping(void)
562 unsigned char i2c_data[2];
563 struct i2c_msg msgs1[1] = {
565 .addr = save_client->addr,
571 struct m41t80_data *clientdata = i2c_get_clientdata(save_client);
573 i2c_data[0] = 0x09; /* watchdog register */
576 i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */
579 * WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02)
581 i2c_data[1] = wdt_margin << 2 | 0x82;
584 * M41T65 has three bits for watchdog resolution. Don't set bit 7, as
585 * that would be an invalid resolution.
587 if (clientdata->features & M41T80_FEATURE_WD)
588 i2c_data[1] &= ~M41T80_WATCHDOG_RB2;
590 i2c_transfer(save_client->adapter, msgs1, 1);
598 static void wdt_disable(void)
600 unsigned char i2c_data[2], i2c_buf[0x10];
601 struct i2c_msg msgs0[2] = {
603 .addr = save_client->addr,
609 .addr = save_client->addr,
615 struct i2c_msg msgs1[1] = {
617 .addr = save_client->addr,
625 i2c_transfer(save_client->adapter, msgs0, 2);
629 i2c_transfer(save_client->adapter, msgs1, 1);
634 * @file: file handle to the watchdog
635 * @buf: buffer to write (unused as data does not matter here
636 * @count: count of bytes
637 * @ppos: pointer to the position to write. No seeks allowed
639 * A write to a watchdog device is defined as a keepalive signal. Any
640 * write of data will do, as we we don't define content meaning.
642 static ssize_t wdt_write(struct file *file, const char __user *buf,
643 size_t count, loff_t *ppos)
652 static ssize_t wdt_read(struct file *file, char __user *buf,
653 size_t count, loff_t *ppos)
660 * @inode: inode of the device
661 * @file: file handle to the device
662 * @cmd: watchdog command
663 * @arg: argument pointer
665 * The watchdog API defines a common set of functions for all watchdogs
666 * according to their available features. We only actually usefully support
667 * querying capabilities and current status.
669 static int wdt_ioctl(struct file *file, unsigned int cmd,
673 static struct watchdog_info ident = {
674 .options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING |
676 .firmware_version = 1,
677 .identity = "M41T80 WTD"
681 case WDIOC_GETSUPPORT:
682 return copy_to_user((struct watchdog_info __user *)arg, &ident,
683 sizeof(ident)) ? -EFAULT : 0;
685 case WDIOC_GETSTATUS:
686 case WDIOC_GETBOOTSTATUS:
687 return put_user(boot_flag, (int __user *)arg);
688 case WDIOC_KEEPALIVE:
691 case WDIOC_SETTIMEOUT:
692 if (get_user(new_margin, (int __user *)arg))
694 /* Arbitrary, can't find the card's limits */
695 if (new_margin < 1 || new_margin > 124)
697 wdt_margin = new_margin;
700 case WDIOC_GETTIMEOUT:
701 return put_user(wdt_margin, (int __user *)arg);
703 case WDIOC_SETOPTIONS:
704 if (copy_from_user(&rv, (int __user *)arg, sizeof(int)))
707 if (rv & WDIOS_DISABLECARD) {
708 pr_info("disable watchdog\n");
712 if (rv & WDIOS_ENABLECARD) {
713 pr_info("enable watchdog\n");
722 static long wdt_unlocked_ioctl(struct file *file, unsigned int cmd,
727 mutex_lock(&m41t80_rtc_mutex);
728 ret = wdt_ioctl(file, cmd, arg);
729 mutex_unlock(&m41t80_rtc_mutex);
736 * @inode: inode of device
737 * @file: file handle to device
740 static int wdt_open(struct inode *inode, struct file *file)
742 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
743 mutex_lock(&m41t80_rtc_mutex);
744 if (test_and_set_bit(0, &wdt_is_open)) {
745 mutex_unlock(&m41t80_rtc_mutex);
752 mutex_unlock(&m41t80_rtc_mutex);
753 return nonseekable_open(inode, file);
760 * @inode: inode to board
761 * @file: file handle to board
764 static int wdt_release(struct inode *inode, struct file *file)
766 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR)
767 clear_bit(0, &wdt_is_open);
773 * @this: our notifier block
774 * @code: the event being reported
777 * Our notifier is called on system shutdowns. We want to turn the card
778 * off at reboot otherwise the machine will reboot again during memory
779 * test or worse yet during the following fsck. This would suck, in fact
780 * trust me - if it happens it does suck.
782 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
785 if (code == SYS_DOWN || code == SYS_HALT)
786 /* Disable Watchdog */
791 static const struct file_operations wdt_fops = {
792 .owner = THIS_MODULE,
794 .unlocked_ioctl = wdt_unlocked_ioctl,
797 .release = wdt_release,
801 static struct miscdevice wdt_dev = {
802 .minor = WATCHDOG_MINOR,
808 * The WDT card needs to learn about soft shutdowns in order to
809 * turn the timebomb registers off.
811 static struct notifier_block wdt_notifier = {
812 .notifier_call = wdt_notify_sys,
814 #endif /* CONFIG_RTC_DRV_M41T80_WDT */
817 *****************************************************************************
821 *****************************************************************************
824 static void m41t80_remove_sysfs_group(void *_dev)
826 struct device *dev = _dev;
828 sysfs_remove_group(&dev->kobj, &attr_group);
831 static int m41t80_probe(struct i2c_client *client,
832 const struct i2c_device_id *id)
834 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
836 struct rtc_device *rtc = NULL;
838 struct m41t80_data *m41t80_data = NULL;
840 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK |
841 I2C_FUNC_SMBUS_BYTE_DATA)) {
842 dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK\n");
846 m41t80_data = devm_kzalloc(&client->dev, sizeof(*m41t80_data),
851 if (client->dev.of_node)
852 m41t80_data->features = (unsigned long)
853 of_device_get_match_data(&client->dev);
855 m41t80_data->features = id->driver_data;
856 i2c_set_clientdata(client, m41t80_data);
858 if (client->irq > 0) {
859 rc = devm_request_threaded_irq(&client->dev, client->irq,
860 NULL, m41t80_handle_irq,
861 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
864 dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
867 m41t80_rtc_ops.read_alarm = m41t80_read_alarm;
868 m41t80_rtc_ops.set_alarm = m41t80_set_alarm;
869 m41t80_rtc_ops.alarm_irq_enable = m41t80_alarm_irq_enable;
870 /* Enable the wakealarm */
871 device_init_wakeup(&client->dev, true);
875 rtc = devm_rtc_device_register(&client->dev, client->name,
876 &m41t80_rtc_ops, THIS_MODULE);
880 m41t80_data->rtc = rtc;
882 /* Make sure HT (Halt Update) bit is cleared */
883 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR);
885 if (rc >= 0 && rc & M41T80_ALHOUR_HT) {
886 if (m41t80_data->features & M41T80_FEATURE_HT) {
887 m41t80_get_datetime(client, &tm);
888 dev_info(&client->dev, "HT bit was set!\n");
889 dev_info(&client->dev,
890 "Power Down at %04i-%02i-%02i %02i:%02i:%02i\n",
892 tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
893 tm.tm_min, tm.tm_sec);
895 rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_HOUR,
896 rc & ~M41T80_ALHOUR_HT);
900 dev_err(&client->dev, "Can't clear HT bit\n");
904 /* Make sure ST (stop) bit is cleared */
905 rc = i2c_smbus_read_byte_data(client, M41T80_REG_SEC);
907 if (rc >= 0 && rc & M41T80_SEC_ST)
908 rc = i2c_smbus_write_byte_data(client, M41T80_REG_SEC,
909 rc & ~M41T80_SEC_ST);
911 dev_err(&client->dev, "Can't clear ST bit\n");
915 /* Export sysfs entries */
916 rc = sysfs_create_group(&(&client->dev)->kobj, &attr_group);
918 dev_err(&client->dev, "Failed to create sysfs group: %d\n", rc);
922 rc = devm_add_action_or_reset(&client->dev, m41t80_remove_sysfs_group,
925 dev_err(&client->dev,
926 "Failed to add sysfs cleanup action: %d\n", rc);
930 #ifdef CONFIG_RTC_DRV_M41T80_WDT
931 if (m41t80_data->features & M41T80_FEATURE_HT) {
932 save_client = client;
933 rc = misc_register(&wdt_dev);
936 rc = register_reboot_notifier(&wdt_notifier);
938 misc_deregister(&wdt_dev);
946 static int m41t80_remove(struct i2c_client *client)
948 #ifdef CONFIG_RTC_DRV_M41T80_WDT
949 struct m41t80_data *clientdata = i2c_get_clientdata(client);
951 if (clientdata->features & M41T80_FEATURE_HT) {
952 misc_deregister(&wdt_dev);
953 unregister_reboot_notifier(&wdt_notifier);
960 static struct i2c_driver m41t80_driver = {
962 .name = "rtc-m41t80",
963 .of_match_table = of_match_ptr(m41t80_of_match),
966 .probe = m41t80_probe,
967 .remove = m41t80_remove,
968 .id_table = m41t80_id,
971 module_i2c_driver(m41t80_driver);
973 MODULE_AUTHOR("Alexander Bigga <ab@mycable.de>");
974 MODULE_DESCRIPTION("ST Microelectronics M41T80 series RTC I2C Client Driver");
975 MODULE_LICENSE("GPL");