nilfs2: unbreak compat ioctl
[zen-stable.git] / drivers / rtc / rtc-m41t80.c
blobeda128fc1d38729ebb1a385c10fd30e6345e852b
1 /*
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 #include <linux/bcd.h>
17 #include <linux/i2c.h>
18 #include <linux/init.h>
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/rtc.h>
22 #include <linux/slab.h>
23 #include <linux/mutex.h>
24 #include <linux/string.h>
25 #ifdef CONFIG_RTC_DRV_M41T80_WDT
26 #include <linux/fs.h>
27 #include <linux/ioctl.h>
28 #include <linux/miscdevice.h>
29 #include <linux/reboot.h>
30 #include <linux/watchdog.h>
31 #endif
33 #define M41T80_REG_SSEC 0
34 #define M41T80_REG_SEC 1
35 #define M41T80_REG_MIN 2
36 #define M41T80_REG_HOUR 3
37 #define M41T80_REG_WDAY 4
38 #define M41T80_REG_DAY 5
39 #define M41T80_REG_MON 6
40 #define M41T80_REG_YEAR 7
41 #define M41T80_REG_ALARM_MON 0xa
42 #define M41T80_REG_ALARM_DAY 0xb
43 #define M41T80_REG_ALARM_HOUR 0xc
44 #define M41T80_REG_ALARM_MIN 0xd
45 #define M41T80_REG_ALARM_SEC 0xe
46 #define M41T80_REG_FLAGS 0xf
47 #define M41T80_REG_SQW 0x13
49 #define M41T80_DATETIME_REG_SIZE (M41T80_REG_YEAR + 1)
50 #define M41T80_ALARM_REG_SIZE \
51 (M41T80_REG_ALARM_SEC + 1 - M41T80_REG_ALARM_MON)
53 #define M41T80_SEC_ST (1 << 7) /* ST: Stop Bit */
54 #define M41T80_ALMON_AFE (1 << 7) /* AFE: AF Enable Bit */
55 #define M41T80_ALMON_SQWE (1 << 6) /* SQWE: SQW Enable Bit */
56 #define M41T80_ALHOUR_HT (1 << 6) /* HT: Halt Update Bit */
57 #define M41T80_FLAGS_AF (1 << 6) /* AF: Alarm Flag Bit */
58 #define M41T80_FLAGS_BATT_LOW (1 << 4) /* BL: Battery Low Bit */
59 #define M41T80_WATCHDOG_RB2 (1 << 7) /* RB: Watchdog resolution */
60 #define M41T80_WATCHDOG_RB1 (1 << 1) /* RB: Watchdog resolution */
61 #define M41T80_WATCHDOG_RB0 (1 << 0) /* RB: Watchdog resolution */
63 #define M41T80_FEATURE_HT (1 << 0) /* Halt feature */
64 #define M41T80_FEATURE_BL (1 << 1) /* Battery low indicator */
65 #define M41T80_FEATURE_SQ (1 << 2) /* Squarewave feature */
66 #define M41T80_FEATURE_WD (1 << 3) /* Extra watchdog resolution */
67 #define M41T80_FEATURE_SQ_ALT (1 << 4) /* RSx bits are in reg 4 */
69 #define DRV_VERSION "0.05"
71 static DEFINE_MUTEX(m41t80_rtc_mutex);
72 static const struct i2c_device_id m41t80_id[] = {
73 { "m41t62", M41T80_FEATURE_SQ | M41T80_FEATURE_SQ_ALT },
74 { "m41t65", M41T80_FEATURE_HT | M41T80_FEATURE_WD },
75 { "m41t80", M41T80_FEATURE_SQ },
76 { "m41t81", M41T80_FEATURE_HT | M41T80_FEATURE_SQ},
77 { "m41t81s", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
78 { "m41t82", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
79 { "m41t83", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
80 { "m41st84", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
81 { "m41st85", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
82 { "m41st87", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
83 { }
85 MODULE_DEVICE_TABLE(i2c, m41t80_id);
87 struct m41t80_data {
88 u8 features;
89 struct rtc_device *rtc;
92 static int m41t80_get_datetime(struct i2c_client *client,
93 struct rtc_time *tm)
95 u8 buf[M41T80_DATETIME_REG_SIZE], dt_addr[1] = { M41T80_REG_SEC };
96 struct i2c_msg msgs[] = {
98 .addr = client->addr,
99 .flags = 0,
100 .len = 1,
101 .buf = dt_addr,
104 .addr = client->addr,
105 .flags = I2C_M_RD,
106 .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
107 .buf = buf + M41T80_REG_SEC,
111 if (i2c_transfer(client->adapter, msgs, 2) < 0) {
112 dev_err(&client->dev, "read error\n");
113 return -EIO;
116 tm->tm_sec = bcd2bin(buf[M41T80_REG_SEC] & 0x7f);
117 tm->tm_min = bcd2bin(buf[M41T80_REG_MIN] & 0x7f);
118 tm->tm_hour = bcd2bin(buf[M41T80_REG_HOUR] & 0x3f);
119 tm->tm_mday = bcd2bin(buf[M41T80_REG_DAY] & 0x3f);
120 tm->tm_wday = buf[M41T80_REG_WDAY] & 0x07;
121 tm->tm_mon = bcd2bin(buf[M41T80_REG_MON] & 0x1f) - 1;
123 /* assume 20YY not 19YY, and ignore the Century Bit */
124 tm->tm_year = bcd2bin(buf[M41T80_REG_YEAR]) + 100;
125 return rtc_valid_tm(tm);
128 /* Sets the given date and time to the real time clock. */
129 static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm)
131 u8 wbuf[1 + M41T80_DATETIME_REG_SIZE];
132 u8 *buf = &wbuf[1];
133 u8 dt_addr[1] = { M41T80_REG_SEC };
134 struct i2c_msg msgs_in[] = {
136 .addr = client->addr,
137 .flags = 0,
138 .len = 1,
139 .buf = dt_addr,
142 .addr = client->addr,
143 .flags = I2C_M_RD,
144 .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
145 .buf = buf + M41T80_REG_SEC,
148 struct i2c_msg msgs[] = {
150 .addr = client->addr,
151 .flags = 0,
152 .len = 1 + M41T80_DATETIME_REG_SIZE,
153 .buf = wbuf,
157 /* Read current reg values into buf[1..7] */
158 if (i2c_transfer(client->adapter, msgs_in, 2) < 0) {
159 dev_err(&client->dev, "read error\n");
160 return -EIO;
163 wbuf[0] = 0; /* offset into rtc's regs */
164 /* Merge time-data and register flags into buf[0..7] */
165 buf[M41T80_REG_SSEC] = 0;
166 buf[M41T80_REG_SEC] =
167 bin2bcd(tm->tm_sec) | (buf[M41T80_REG_SEC] & ~0x7f);
168 buf[M41T80_REG_MIN] =
169 bin2bcd(tm->tm_min) | (buf[M41T80_REG_MIN] & ~0x7f);
170 buf[M41T80_REG_HOUR] =
171 bin2bcd(tm->tm_hour) | (buf[M41T80_REG_HOUR] & ~0x3f) ;
172 buf[M41T80_REG_WDAY] =
173 (tm->tm_wday & 0x07) | (buf[M41T80_REG_WDAY] & ~0x07);
174 buf[M41T80_REG_DAY] =
175 bin2bcd(tm->tm_mday) | (buf[M41T80_REG_DAY] & ~0x3f);
176 buf[M41T80_REG_MON] =
177 bin2bcd(tm->tm_mon + 1) | (buf[M41T80_REG_MON] & ~0x1f);
178 /* assume 20YY not 19YY */
179 buf[M41T80_REG_YEAR] = bin2bcd(tm->tm_year % 100);
181 if (i2c_transfer(client->adapter, msgs, 1) != 1) {
182 dev_err(&client->dev, "write error\n");
183 return -EIO;
185 return 0;
188 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
189 static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq)
191 struct i2c_client *client = to_i2c_client(dev);
192 struct m41t80_data *clientdata = i2c_get_clientdata(client);
193 u8 reg;
195 if (clientdata->features & M41T80_FEATURE_BL) {
196 reg = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
197 seq_printf(seq, "battery\t\t: %s\n",
198 (reg & M41T80_FLAGS_BATT_LOW) ? "exhausted" : "ok");
200 return 0;
202 #else
203 #define m41t80_rtc_proc NULL
204 #endif
206 static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm)
208 return m41t80_get_datetime(to_i2c_client(dev), tm);
211 static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm)
213 return m41t80_set_datetime(to_i2c_client(dev), tm);
216 static int m41t80_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
218 struct i2c_client *client = to_i2c_client(dev);
219 int rc;
221 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
222 if (rc < 0)
223 goto err;
225 if (enabled)
226 rc |= M41T80_ALMON_AFE;
227 else
228 rc &= ~M41T80_ALMON_AFE;
230 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, rc) < 0)
231 goto err;
233 return 0;
234 err:
235 return -EIO;
238 static int m41t80_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *t)
240 struct i2c_client *client = to_i2c_client(dev);
241 u8 wbuf[1 + M41T80_ALARM_REG_SIZE];
242 u8 *buf = &wbuf[1];
243 u8 *reg = buf - M41T80_REG_ALARM_MON;
244 u8 dt_addr[1] = { M41T80_REG_ALARM_MON };
245 struct i2c_msg msgs_in[] = {
247 .addr = client->addr,
248 .flags = 0,
249 .len = 1,
250 .buf = dt_addr,
253 .addr = client->addr,
254 .flags = I2C_M_RD,
255 .len = M41T80_ALARM_REG_SIZE,
256 .buf = buf,
259 struct i2c_msg msgs[] = {
261 .addr = client->addr,
262 .flags = 0,
263 .len = 1 + M41T80_ALARM_REG_SIZE,
264 .buf = wbuf,
268 if (i2c_transfer(client->adapter, msgs_in, 2) < 0) {
269 dev_err(&client->dev, "read error\n");
270 return -EIO;
272 reg[M41T80_REG_ALARM_MON] &= ~(0x1f | M41T80_ALMON_AFE);
273 reg[M41T80_REG_ALARM_DAY] = 0;
274 reg[M41T80_REG_ALARM_HOUR] &= ~(0x3f | 0x80);
275 reg[M41T80_REG_ALARM_MIN] = 0;
276 reg[M41T80_REG_ALARM_SEC] = 0;
278 wbuf[0] = M41T80_REG_ALARM_MON; /* offset into rtc's regs */
279 reg[M41T80_REG_ALARM_SEC] |= t->time.tm_sec >= 0 ?
280 bin2bcd(t->time.tm_sec) : 0x80;
281 reg[M41T80_REG_ALARM_MIN] |= t->time.tm_min >= 0 ?
282 bin2bcd(t->time.tm_min) : 0x80;
283 reg[M41T80_REG_ALARM_HOUR] |= t->time.tm_hour >= 0 ?
284 bin2bcd(t->time.tm_hour) : 0x80;
285 reg[M41T80_REG_ALARM_DAY] |= t->time.tm_mday >= 0 ?
286 bin2bcd(t->time.tm_mday) : 0x80;
287 if (t->time.tm_mon >= 0)
288 reg[M41T80_REG_ALARM_MON] |= bin2bcd(t->time.tm_mon + 1);
289 else
290 reg[M41T80_REG_ALARM_DAY] |= 0x40;
292 if (i2c_transfer(client->adapter, msgs, 1) != 1) {
293 dev_err(&client->dev, "write error\n");
294 return -EIO;
297 if (t->enabled) {
298 reg[M41T80_REG_ALARM_MON] |= M41T80_ALMON_AFE;
299 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
300 reg[M41T80_REG_ALARM_MON]) < 0) {
301 dev_err(&client->dev, "write error\n");
302 return -EIO;
305 return 0;
308 static int m41t80_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *t)
310 struct i2c_client *client = to_i2c_client(dev);
311 u8 buf[M41T80_ALARM_REG_SIZE + 1]; /* all alarm regs and flags */
312 u8 dt_addr[1] = { M41T80_REG_ALARM_MON };
313 u8 *reg = buf - M41T80_REG_ALARM_MON;
314 struct i2c_msg msgs[] = {
316 .addr = client->addr,
317 .flags = 0,
318 .len = 1,
319 .buf = dt_addr,
322 .addr = client->addr,
323 .flags = I2C_M_RD,
324 .len = M41T80_ALARM_REG_SIZE + 1,
325 .buf = buf,
329 if (i2c_transfer(client->adapter, msgs, 2) < 0) {
330 dev_err(&client->dev, "read error\n");
331 return -EIO;
333 t->time.tm_sec = -1;
334 t->time.tm_min = -1;
335 t->time.tm_hour = -1;
336 t->time.tm_mday = -1;
337 t->time.tm_mon = -1;
338 if (!(reg[M41T80_REG_ALARM_SEC] & 0x80))
339 t->time.tm_sec = bcd2bin(reg[M41T80_REG_ALARM_SEC] & 0x7f);
340 if (!(reg[M41T80_REG_ALARM_MIN] & 0x80))
341 t->time.tm_min = bcd2bin(reg[M41T80_REG_ALARM_MIN] & 0x7f);
342 if (!(reg[M41T80_REG_ALARM_HOUR] & 0x80))
343 t->time.tm_hour = bcd2bin(reg[M41T80_REG_ALARM_HOUR] & 0x3f);
344 if (!(reg[M41T80_REG_ALARM_DAY] & 0x80))
345 t->time.tm_mday = bcd2bin(reg[M41T80_REG_ALARM_DAY] & 0x3f);
346 if (!(reg[M41T80_REG_ALARM_DAY] & 0x40))
347 t->time.tm_mon = bcd2bin(reg[M41T80_REG_ALARM_MON] & 0x1f) - 1;
348 t->time.tm_year = -1;
349 t->time.tm_wday = -1;
350 t->time.tm_yday = -1;
351 t->time.tm_isdst = -1;
352 t->enabled = !!(reg[M41T80_REG_ALARM_MON] & M41T80_ALMON_AFE);
353 t->pending = !!(reg[M41T80_REG_FLAGS] & M41T80_FLAGS_AF);
354 return 0;
357 static struct rtc_class_ops m41t80_rtc_ops = {
358 .read_time = m41t80_rtc_read_time,
359 .set_time = m41t80_rtc_set_time,
360 .read_alarm = m41t80_rtc_read_alarm,
361 .set_alarm = m41t80_rtc_set_alarm,
362 .proc = m41t80_rtc_proc,
363 .alarm_irq_enable = m41t80_rtc_alarm_irq_enable,
366 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
367 static ssize_t m41t80_sysfs_show_flags(struct device *dev,
368 struct device_attribute *attr, char *buf)
370 struct i2c_client *client = to_i2c_client(dev);
371 int val;
373 val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
374 if (val < 0)
375 return -EIO;
376 return sprintf(buf, "%#x\n", val);
378 static DEVICE_ATTR(flags, S_IRUGO, m41t80_sysfs_show_flags, NULL);
380 static ssize_t m41t80_sysfs_show_sqwfreq(struct device *dev,
381 struct device_attribute *attr, char *buf)
383 struct i2c_client *client = to_i2c_client(dev);
384 struct m41t80_data *clientdata = i2c_get_clientdata(client);
385 int val, reg_sqw;
387 if (!(clientdata->features & M41T80_FEATURE_SQ))
388 return -EINVAL;
390 reg_sqw = M41T80_REG_SQW;
391 if (clientdata->features & M41T80_FEATURE_SQ_ALT)
392 reg_sqw = M41T80_REG_WDAY;
393 val = i2c_smbus_read_byte_data(client, reg_sqw);
394 if (val < 0)
395 return -EIO;
396 val = (val >> 4) & 0xf;
397 switch (val) {
398 case 0:
399 break;
400 case 1:
401 val = 32768;
402 break;
403 default:
404 val = 32768 >> val;
406 return sprintf(buf, "%d\n", val);
408 static ssize_t m41t80_sysfs_set_sqwfreq(struct device *dev,
409 struct device_attribute *attr,
410 const char *buf, size_t count)
412 struct i2c_client *client = to_i2c_client(dev);
413 struct m41t80_data *clientdata = i2c_get_clientdata(client);
414 int almon, sqw, reg_sqw;
415 int val = simple_strtoul(buf, NULL, 0);
417 if (!(clientdata->features & M41T80_FEATURE_SQ))
418 return -EINVAL;
420 if (val) {
421 if (!is_power_of_2(val))
422 return -EINVAL;
423 val = ilog2(val);
424 if (val == 15)
425 val = 1;
426 else if (val < 14)
427 val = 15 - val;
428 else
429 return -EINVAL;
431 /* disable SQW, set SQW frequency & re-enable */
432 almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
433 if (almon < 0)
434 return -EIO;
435 reg_sqw = M41T80_REG_SQW;
436 if (clientdata->features & M41T80_FEATURE_SQ_ALT)
437 reg_sqw = M41T80_REG_WDAY;
438 sqw = i2c_smbus_read_byte_data(client, reg_sqw);
439 if (sqw < 0)
440 return -EIO;
441 sqw = (sqw & 0x0f) | (val << 4);
442 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
443 almon & ~M41T80_ALMON_SQWE) < 0 ||
444 i2c_smbus_write_byte_data(client, reg_sqw, sqw) < 0)
445 return -EIO;
446 if (val && i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
447 almon | M41T80_ALMON_SQWE) < 0)
448 return -EIO;
449 return count;
451 static DEVICE_ATTR(sqwfreq, S_IRUGO | S_IWUSR,
452 m41t80_sysfs_show_sqwfreq, m41t80_sysfs_set_sqwfreq);
454 static struct attribute *attrs[] = {
455 &dev_attr_flags.attr,
456 &dev_attr_sqwfreq.attr,
457 NULL,
459 static struct attribute_group attr_group = {
460 .attrs = attrs,
463 static int m41t80_sysfs_register(struct device *dev)
465 return sysfs_create_group(&dev->kobj, &attr_group);
467 #else
468 static int m41t80_sysfs_register(struct device *dev)
470 return 0;
472 #endif
474 #ifdef CONFIG_RTC_DRV_M41T80_WDT
476 *****************************************************************************
478 * Watchdog Driver
480 *****************************************************************************
482 static struct i2c_client *save_client;
484 /* Default margin */
485 #define WD_TIMO 60 /* 1..31 seconds */
487 static int wdt_margin = WD_TIMO;
488 module_param(wdt_margin, int, 0);
489 MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)");
491 static unsigned long wdt_is_open;
492 static int boot_flag;
495 * wdt_ping:
497 * Reload counter one with the watchdog timeout. We don't bother reloading
498 * the cascade counter.
500 static void wdt_ping(void)
502 unsigned char i2c_data[2];
503 struct i2c_msg msgs1[1] = {
505 .addr = save_client->addr,
506 .flags = 0,
507 .len = 2,
508 .buf = i2c_data,
511 struct m41t80_data *clientdata = i2c_get_clientdata(save_client);
513 i2c_data[0] = 0x09; /* watchdog register */
515 if (wdt_margin > 31)
516 i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */
517 else
519 * WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02)
521 i2c_data[1] = wdt_margin<<2 | 0x82;
524 * M41T65 has three bits for watchdog resolution. Don't set bit 7, as
525 * that would be an invalid resolution.
527 if (clientdata->features & M41T80_FEATURE_WD)
528 i2c_data[1] &= ~M41T80_WATCHDOG_RB2;
530 i2c_transfer(save_client->adapter, msgs1, 1);
534 * wdt_disable:
536 * disables watchdog.
538 static void wdt_disable(void)
540 unsigned char i2c_data[2], i2c_buf[0x10];
541 struct i2c_msg msgs0[2] = {
543 .addr = save_client->addr,
544 .flags = 0,
545 .len = 1,
546 .buf = i2c_data,
549 .addr = save_client->addr,
550 .flags = I2C_M_RD,
551 .len = 1,
552 .buf = i2c_buf,
555 struct i2c_msg msgs1[1] = {
557 .addr = save_client->addr,
558 .flags = 0,
559 .len = 2,
560 .buf = i2c_data,
564 i2c_data[0] = 0x09;
565 i2c_transfer(save_client->adapter, msgs0, 2);
567 i2c_data[0] = 0x09;
568 i2c_data[1] = 0x00;
569 i2c_transfer(save_client->adapter, msgs1, 1);
573 * wdt_write:
574 * @file: file handle to the watchdog
575 * @buf: buffer to write (unused as data does not matter here
576 * @count: count of bytes
577 * @ppos: pointer to the position to write. No seeks allowed
579 * A write to a watchdog device is defined as a keepalive signal. Any
580 * write of data will do, as we we don't define content meaning.
582 static ssize_t wdt_write(struct file *file, const char __user *buf,
583 size_t count, loff_t *ppos)
585 if (count) {
586 wdt_ping();
587 return 1;
589 return 0;
592 static ssize_t wdt_read(struct file *file, char __user *buf,
593 size_t count, loff_t *ppos)
595 return 0;
599 * wdt_ioctl:
600 * @inode: inode of the device
601 * @file: file handle to the device
602 * @cmd: watchdog command
603 * @arg: argument pointer
605 * The watchdog API defines a common set of functions for all watchdogs
606 * according to their available features. We only actually usefully support
607 * querying capabilities and current status.
609 static int wdt_ioctl(struct file *file, unsigned int cmd,
610 unsigned long arg)
612 int new_margin, rv;
613 static struct watchdog_info ident = {
614 .options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING |
615 WDIOF_SETTIMEOUT,
616 .firmware_version = 1,
617 .identity = "M41T80 WTD"
620 switch (cmd) {
621 case WDIOC_GETSUPPORT:
622 return copy_to_user((struct watchdog_info __user *)arg, &ident,
623 sizeof(ident)) ? -EFAULT : 0;
625 case WDIOC_GETSTATUS:
626 case WDIOC_GETBOOTSTATUS:
627 return put_user(boot_flag, (int __user *)arg);
628 case WDIOC_KEEPALIVE:
629 wdt_ping();
630 return 0;
631 case WDIOC_SETTIMEOUT:
632 if (get_user(new_margin, (int __user *)arg))
633 return -EFAULT;
634 /* Arbitrary, can't find the card's limits */
635 if (new_margin < 1 || new_margin > 124)
636 return -EINVAL;
637 wdt_margin = new_margin;
638 wdt_ping();
639 /* Fall */
640 case WDIOC_GETTIMEOUT:
641 return put_user(wdt_margin, (int __user *)arg);
643 case WDIOC_SETOPTIONS:
644 if (copy_from_user(&rv, (int __user *)arg, sizeof(int)))
645 return -EFAULT;
647 if (rv & WDIOS_DISABLECARD) {
648 pr_info("rtc-m41t80: disable watchdog\n");
649 wdt_disable();
652 if (rv & WDIOS_ENABLECARD) {
653 pr_info("rtc-m41t80: enable watchdog\n");
654 wdt_ping();
657 return -EINVAL;
659 return -ENOTTY;
662 static long wdt_unlocked_ioctl(struct file *file, unsigned int cmd,
663 unsigned long arg)
665 int ret;
667 mutex_lock(&m41t80_rtc_mutex);
668 ret = wdt_ioctl(file, cmd, arg);
669 mutex_unlock(&m41t80_rtc_mutex);
671 return ret;
675 * wdt_open:
676 * @inode: inode of device
677 * @file: file handle to device
680 static int wdt_open(struct inode *inode, struct file *file)
682 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
683 mutex_lock(&m41t80_rtc_mutex);
684 if (test_and_set_bit(0, &wdt_is_open)) {
685 mutex_unlock(&m41t80_rtc_mutex);
686 return -EBUSY;
689 * Activate
691 wdt_is_open = 1;
692 mutex_unlock(&m41t80_rtc_mutex);
693 return nonseekable_open(inode, file);
695 return -ENODEV;
699 * wdt_close:
700 * @inode: inode to board
701 * @file: file handle to board
704 static int wdt_release(struct inode *inode, struct file *file)
706 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR)
707 clear_bit(0, &wdt_is_open);
708 return 0;
712 * notify_sys:
713 * @this: our notifier block
714 * @code: the event being reported
715 * @unused: unused
717 * Our notifier is called on system shutdowns. We want to turn the card
718 * off at reboot otherwise the machine will reboot again during memory
719 * test or worse yet during the following fsck. This would suck, in fact
720 * trust me - if it happens it does suck.
722 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
723 void *unused)
725 if (code == SYS_DOWN || code == SYS_HALT)
726 /* Disable Watchdog */
727 wdt_disable();
728 return NOTIFY_DONE;
731 static const struct file_operations wdt_fops = {
732 .owner = THIS_MODULE,
733 .read = wdt_read,
734 .unlocked_ioctl = wdt_unlocked_ioctl,
735 .write = wdt_write,
736 .open = wdt_open,
737 .release = wdt_release,
738 .llseek = no_llseek,
741 static struct miscdevice wdt_dev = {
742 .minor = WATCHDOG_MINOR,
743 .name = "watchdog",
744 .fops = &wdt_fops,
748 * The WDT card needs to learn about soft shutdowns in order to
749 * turn the timebomb registers off.
751 static struct notifier_block wdt_notifier = {
752 .notifier_call = wdt_notify_sys,
754 #endif /* CONFIG_RTC_DRV_M41T80_WDT */
757 *****************************************************************************
759 * Driver Interface
761 *****************************************************************************
763 static int m41t80_probe(struct i2c_client *client,
764 const struct i2c_device_id *id)
766 int rc = 0;
767 struct rtc_device *rtc = NULL;
768 struct rtc_time tm;
769 struct m41t80_data *clientdata = NULL;
771 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C
772 | I2C_FUNC_SMBUS_BYTE_DATA)) {
773 rc = -ENODEV;
774 goto exit;
777 dev_info(&client->dev,
778 "chip found, driver version " DRV_VERSION "\n");
780 clientdata = kzalloc(sizeof(*clientdata), GFP_KERNEL);
781 if (!clientdata) {
782 rc = -ENOMEM;
783 goto exit;
786 clientdata->features = id->driver_data;
787 i2c_set_clientdata(client, clientdata);
789 rtc = rtc_device_register(client->name, &client->dev,
790 &m41t80_rtc_ops, THIS_MODULE);
791 if (IS_ERR(rtc)) {
792 rc = PTR_ERR(rtc);
793 rtc = NULL;
794 goto exit;
797 clientdata->rtc = rtc;
799 /* Make sure HT (Halt Update) bit is cleared */
800 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR);
801 if (rc < 0)
802 goto ht_err;
804 if (rc & M41T80_ALHOUR_HT) {
805 if (clientdata->features & M41T80_FEATURE_HT) {
806 m41t80_get_datetime(client, &tm);
807 dev_info(&client->dev, "HT bit was set!\n");
808 dev_info(&client->dev,
809 "Power Down at "
810 "%04i-%02i-%02i %02i:%02i:%02i\n",
811 tm.tm_year + 1900,
812 tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
813 tm.tm_min, tm.tm_sec);
815 if (i2c_smbus_write_byte_data(client,
816 M41T80_REG_ALARM_HOUR,
817 rc & ~M41T80_ALHOUR_HT) < 0)
818 goto ht_err;
821 /* Make sure ST (stop) bit is cleared */
822 rc = i2c_smbus_read_byte_data(client, M41T80_REG_SEC);
823 if (rc < 0)
824 goto st_err;
826 if (rc & M41T80_SEC_ST) {
827 if (i2c_smbus_write_byte_data(client, M41T80_REG_SEC,
828 rc & ~M41T80_SEC_ST) < 0)
829 goto st_err;
832 rc = m41t80_sysfs_register(&client->dev);
833 if (rc)
834 goto exit;
836 #ifdef CONFIG_RTC_DRV_M41T80_WDT
837 if (clientdata->features & M41T80_FEATURE_HT) {
838 save_client = client;
839 rc = misc_register(&wdt_dev);
840 if (rc)
841 goto exit;
842 rc = register_reboot_notifier(&wdt_notifier);
843 if (rc) {
844 misc_deregister(&wdt_dev);
845 goto exit;
848 #endif
849 return 0;
851 st_err:
852 rc = -EIO;
853 dev_err(&client->dev, "Can't clear ST bit\n");
854 goto exit;
855 ht_err:
856 rc = -EIO;
857 dev_err(&client->dev, "Can't clear HT bit\n");
858 goto exit;
860 exit:
861 if (rtc)
862 rtc_device_unregister(rtc);
863 kfree(clientdata);
864 return rc;
867 static int m41t80_remove(struct i2c_client *client)
869 struct m41t80_data *clientdata = i2c_get_clientdata(client);
870 struct rtc_device *rtc = clientdata->rtc;
872 #ifdef CONFIG_RTC_DRV_M41T80_WDT
873 if (clientdata->features & M41T80_FEATURE_HT) {
874 misc_deregister(&wdt_dev);
875 unregister_reboot_notifier(&wdt_notifier);
877 #endif
878 if (rtc)
879 rtc_device_unregister(rtc);
880 kfree(clientdata);
882 return 0;
885 static struct i2c_driver m41t80_driver = {
886 .driver = {
887 .name = "rtc-m41t80",
889 .probe = m41t80_probe,
890 .remove = m41t80_remove,
891 .id_table = m41t80_id,
894 static int __init m41t80_rtc_init(void)
896 return i2c_add_driver(&m41t80_driver);
899 static void __exit m41t80_rtc_exit(void)
901 i2c_del_driver(&m41t80_driver);
904 MODULE_AUTHOR("Alexander Bigga <ab@mycable.de>");
905 MODULE_DESCRIPTION("ST Microelectronics M41T80 series RTC I2C Client Driver");
906 MODULE_LICENSE("GPL");
907 MODULE_VERSION(DRV_VERSION);
909 module_init(m41t80_rtc_init);
910 module_exit(m41t80_rtc_exit);