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Atsushi Nemotocaaff562007-07-17 04:05:02 -07001/*
2 * I2C client/driver for the ST M41T80 family of i2c rtc chips.
3 *
4 * Author: Alexander Bigga <ab@mycable.de>
5 *
6 * Based on m41t00.c by Mark A. Greer <mgreer@mvista.com>
7 *
8 * 2006 (c) mycable GmbH
9 *
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.
13 *
14 */
15
Maciej W. Rozycki35aa64f2008-07-23 21:30:29 -070016#include <linux/bcd.h>
17#include <linux/i2c.h>
Atsushi Nemotocaaff562007-07-17 04:05:02 -070018#include <linux/init.h>
Maciej W. Rozycki9fb1f682008-05-12 14:02:38 -070019#include <linux/kernel.h>
Maciej W. Rozycki35aa64f2008-07-23 21:30:29 -070020#include <linux/module.h>
21#include <linux/rtc.h>
Atsushi Nemotocaaff562007-07-17 04:05:02 -070022#include <linux/slab.h>
Arnd Bergmann613655f2010-06-02 14:28:52 +020023#include <linux/mutex.h>
Atsushi Nemotocaaff562007-07-17 04:05:02 -070024#include <linux/string.h>
Atsushi Nemoto617780d2007-07-17 04:05:04 -070025#ifdef CONFIG_RTC_DRV_M41T80_WDT
Atsushi Nemoto617780d2007-07-17 04:05:04 -070026#include <linux/fs.h>
27#include <linux/ioctl.h>
Maciej W. Rozycki35aa64f2008-07-23 21:30:29 -070028#include <linux/miscdevice.h>
29#include <linux/reboot.h>
30#include <linux/watchdog.h>
Atsushi Nemoto617780d2007-07-17 04:05:04 -070031#endif
Atsushi Nemotocaaff562007-07-17 04:05:02 -070032
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
48
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)
52
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 */
Steven A. Falcod3a126f2008-10-15 22:03:07 -070059#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 */
Atsushi Nemotocaaff562007-07-17 04:05:02 -070062
Steven A. Falcod3a126f2008-10-15 22:03:07 -070063#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 */
Daniel Glocknerf30281f2009-04-02 16:57:03 -070067#define M41T80_FEATURE_SQ_ALT (1 << 4) /* RSx bits are in reg 4 */
Atsushi Nemotocaaff562007-07-17 04:05:02 -070068
69#define DRV_VERSION "0.05"
70
Arnd Bergmann613655f2010-06-02 14:28:52 +020071static DEFINE_MUTEX(m41t80_rtc_mutex);
Jean Delvare3760f732008-04-29 23:11:40 +020072static const struct i2c_device_id m41t80_id[] = {
Daniel Glocknerf30281f2009-04-02 16:57:03 -070073 { "m41t62", M41T80_FEATURE_SQ | M41T80_FEATURE_SQ_ALT },
Steven A. Falcod3a126f2008-10-15 22:03:07 -070074 { "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 },
Jean Delvare3760f732008-04-29 23:11:40 +020083 { }
Atsushi Nemotocaaff562007-07-17 04:05:02 -070084};
Jean Delvare3760f732008-04-29 23:11:40 +020085MODULE_DEVICE_TABLE(i2c, m41t80_id);
Atsushi Nemotocaaff562007-07-17 04:05:02 -070086
87struct m41t80_data {
Jean Delvare3760f732008-04-29 23:11:40 +020088 u8 features;
Atsushi Nemotocaaff562007-07-17 04:05:02 -070089 struct rtc_device *rtc;
90};
91
92static int m41t80_get_datetime(struct i2c_client *client,
93 struct rtc_time *tm)
94{
95 u8 buf[M41T80_DATETIME_REG_SIZE], dt_addr[1] = { M41T80_REG_SEC };
96 struct i2c_msg msgs[] = {
97 {
98 .addr = client->addr,
99 .flags = 0,
100 .len = 1,
101 .buf = dt_addr,
102 },
103 {
104 .addr = client->addr,
105 .flags = I2C_M_RD,
106 .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
107 .buf = buf + M41T80_REG_SEC,
108 },
109 };
110
111 if (i2c_transfer(client->adapter, msgs, 2) < 0) {
112 dev_err(&client->dev, "read error\n");
113 return -EIO;
114 }
115
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700116 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);
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700120 tm->tm_wday = buf[M41T80_REG_WDAY] & 0x07;
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700121 tm->tm_mon = bcd2bin(buf[M41T80_REG_MON] & 0x1f) - 1;
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700122
123 /* assume 20YY not 19YY, and ignore the Century Bit */
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700124 tm->tm_year = bcd2bin(buf[M41T80_REG_YEAR]) + 100;
Wan ZongShunb485fe52010-08-10 18:02:15 -0700125 return rtc_valid_tm(tm);
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700126}
127
128/* Sets the given date and time to the real time clock. */
129static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm)
130{
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[] = {
135 {
136 .addr = client->addr,
137 .flags = 0,
138 .len = 1,
139 .buf = dt_addr,
140 },
141 {
142 .addr = client->addr,
143 .flags = I2C_M_RD,
144 .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
145 .buf = buf + M41T80_REG_SEC,
146 },
147 };
148 struct i2c_msg msgs[] = {
149 {
150 .addr = client->addr,
151 .flags = 0,
152 .len = 1 + M41T80_DATETIME_REG_SIZE,
153 .buf = wbuf,
154 },
155 };
156
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;
161 }
162
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] =
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700167 bin2bcd(tm->tm_sec) | (buf[M41T80_REG_SEC] & ~0x7f);
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700168 buf[M41T80_REG_MIN] =
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700169 bin2bcd(tm->tm_min) | (buf[M41T80_REG_MIN] & ~0x7f);
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700170 buf[M41T80_REG_HOUR] =
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700171 bin2bcd(tm->tm_hour) | (buf[M41T80_REG_HOUR] & ~0x3f) ;
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700172 buf[M41T80_REG_WDAY] =
173 (tm->tm_wday & 0x07) | (buf[M41T80_REG_WDAY] & ~0x07);
174 buf[M41T80_REG_DAY] =
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700175 bin2bcd(tm->tm_mday) | (buf[M41T80_REG_DAY] & ~0x3f);
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700176 buf[M41T80_REG_MON] =
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700177 bin2bcd(tm->tm_mon + 1) | (buf[M41T80_REG_MON] & ~0x1f);
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700178 /* assume 20YY not 19YY */
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700179 buf[M41T80_REG_YEAR] = bin2bcd(tm->tm_year % 100);
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700180
181 if (i2c_transfer(client->adapter, msgs, 1) != 1) {
182 dev_err(&client->dev, "write error\n");
183 return -EIO;
184 }
185 return 0;
186}
187
188#if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
189static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq)
190{
191 struct i2c_client *client = to_i2c_client(dev);
192 struct m41t80_data *clientdata = i2c_get_clientdata(client);
193 u8 reg;
194
Jean Delvare3760f732008-04-29 23:11:40 +0200195 if (clientdata->features & M41T80_FEATURE_BL) {
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700196 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");
199 }
200 return 0;
201}
202#else
203#define m41t80_rtc_proc NULL
204#endif
205
206static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm)
207{
208 return m41t80_get_datetime(to_i2c_client(dev), tm);
209}
210
211static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm)
212{
213 return m41t80_set_datetime(to_i2c_client(dev), tm);
214}
215
Paul Bolle48e97662012-10-04 17:14:35 -0700216/*
217 * XXX - m41t80 alarm functionality is reported broken.
218 * until it is fixed, don't register alarm functions.
219 */
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700220static struct rtc_class_ops m41t80_rtc_ops = {
221 .read_time = m41t80_rtc_read_time,
222 .set_time = m41t80_rtc_set_time,
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700223 .proc = m41t80_rtc_proc,
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700224};
225
226#if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
227static ssize_t m41t80_sysfs_show_flags(struct device *dev,
228 struct device_attribute *attr, char *buf)
229{
230 struct i2c_client *client = to_i2c_client(dev);
231 int val;
232
233 val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
234 if (val < 0)
235 return -EIO;
236 return sprintf(buf, "%#x\n", val);
237}
238static DEVICE_ATTR(flags, S_IRUGO, m41t80_sysfs_show_flags, NULL);
239
240static ssize_t m41t80_sysfs_show_sqwfreq(struct device *dev,
241 struct device_attribute *attr, char *buf)
242{
243 struct i2c_client *client = to_i2c_client(dev);
Steven A. Falcod3a126f2008-10-15 22:03:07 -0700244 struct m41t80_data *clientdata = i2c_get_clientdata(client);
Daniel Glocknerf30281f2009-04-02 16:57:03 -0700245 int val, reg_sqw;
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700246
Steven A. Falcod3a126f2008-10-15 22:03:07 -0700247 if (!(clientdata->features & M41T80_FEATURE_SQ))
248 return -EINVAL;
249
Daniel Glocknerf30281f2009-04-02 16:57:03 -0700250 reg_sqw = M41T80_REG_SQW;
251 if (clientdata->features & M41T80_FEATURE_SQ_ALT)
252 reg_sqw = M41T80_REG_WDAY;
253 val = i2c_smbus_read_byte_data(client, reg_sqw);
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700254 if (val < 0)
255 return -EIO;
256 val = (val >> 4) & 0xf;
257 switch (val) {
258 case 0:
259 break;
260 case 1:
261 val = 32768;
262 break;
263 default:
264 val = 32768 >> val;
265 }
266 return sprintf(buf, "%d\n", val);
267}
268static ssize_t m41t80_sysfs_set_sqwfreq(struct device *dev,
269 struct device_attribute *attr,
270 const char *buf, size_t count)
271{
272 struct i2c_client *client = to_i2c_client(dev);
Steven A. Falcod3a126f2008-10-15 22:03:07 -0700273 struct m41t80_data *clientdata = i2c_get_clientdata(client);
Daniel Glocknerf30281f2009-04-02 16:57:03 -0700274 int almon, sqw, reg_sqw;
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700275 int val = simple_strtoul(buf, NULL, 0);
276
Steven A. Falcod3a126f2008-10-15 22:03:07 -0700277 if (!(clientdata->features & M41T80_FEATURE_SQ))
278 return -EINVAL;
279
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700280 if (val) {
281 if (!is_power_of_2(val))
282 return -EINVAL;
283 val = ilog2(val);
284 if (val == 15)
285 val = 1;
286 else if (val < 14)
287 val = 15 - val;
288 else
289 return -EINVAL;
290 }
291 /* disable SQW, set SQW frequency & re-enable */
292 almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
293 if (almon < 0)
294 return -EIO;
Daniel Glocknerf30281f2009-04-02 16:57:03 -0700295 reg_sqw = M41T80_REG_SQW;
296 if (clientdata->features & M41T80_FEATURE_SQ_ALT)
297 reg_sqw = M41T80_REG_WDAY;
298 sqw = i2c_smbus_read_byte_data(client, reg_sqw);
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700299 if (sqw < 0)
300 return -EIO;
301 sqw = (sqw & 0x0f) | (val << 4);
302 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
303 almon & ~M41T80_ALMON_SQWE) < 0 ||
Daniel Glocknerf30281f2009-04-02 16:57:03 -0700304 i2c_smbus_write_byte_data(client, reg_sqw, sqw) < 0)
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700305 return -EIO;
306 if (val && i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
307 almon | M41T80_ALMON_SQWE) < 0)
308 return -EIO;
309 return count;
310}
311static DEVICE_ATTR(sqwfreq, S_IRUGO | S_IWUSR,
312 m41t80_sysfs_show_sqwfreq, m41t80_sysfs_set_sqwfreq);
313
314static struct attribute *attrs[] = {
315 &dev_attr_flags.attr,
316 &dev_attr_sqwfreq.attr,
317 NULL,
318};
319static struct attribute_group attr_group = {
320 .attrs = attrs,
321};
322
323static int m41t80_sysfs_register(struct device *dev)
324{
325 return sysfs_create_group(&dev->kobj, &attr_group);
326}
327#else
328static int m41t80_sysfs_register(struct device *dev)
329{
330 return 0;
331}
332#endif
333
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700334#ifdef CONFIG_RTC_DRV_M41T80_WDT
335/*
336 *****************************************************************************
337 *
338 * Watchdog Driver
339 *
340 *****************************************************************************
341 */
342static struct i2c_client *save_client;
343
344/* Default margin */
345#define WD_TIMO 60 /* 1..31 seconds */
346
347static int wdt_margin = WD_TIMO;
348module_param(wdt_margin, int, 0);
349MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)");
350
351static unsigned long wdt_is_open;
352static int boot_flag;
353
354/**
355 * wdt_ping:
356 *
357 * Reload counter one with the watchdog timeout. We don't bother reloading
358 * the cascade counter.
359 */
360static void wdt_ping(void)
361{
362 unsigned char i2c_data[2];
363 struct i2c_msg msgs1[1] = {
364 {
365 .addr = save_client->addr,
366 .flags = 0,
367 .len = 2,
368 .buf = i2c_data,
369 },
370 };
Steven A. Falcod3a126f2008-10-15 22:03:07 -0700371 struct m41t80_data *clientdata = i2c_get_clientdata(save_client);
372
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700373 i2c_data[0] = 0x09; /* watchdog register */
374
375 if (wdt_margin > 31)
376 i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */
377 else
378 /*
379 * WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02)
380 */
381 i2c_data[1] = wdt_margin<<2 | 0x82;
382
Steven A. Falcod3a126f2008-10-15 22:03:07 -0700383 /*
384 * M41T65 has three bits for watchdog resolution. Don't set bit 7, as
385 * that would be an invalid resolution.
386 */
387 if (clientdata->features & M41T80_FEATURE_WD)
388 i2c_data[1] &= ~M41T80_WATCHDOG_RB2;
389
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700390 i2c_transfer(save_client->adapter, msgs1, 1);
391}
392
393/**
394 * wdt_disable:
395 *
396 * disables watchdog.
397 */
398static void wdt_disable(void)
399{
400 unsigned char i2c_data[2], i2c_buf[0x10];
401 struct i2c_msg msgs0[2] = {
402 {
403 .addr = save_client->addr,
404 .flags = 0,
405 .len = 1,
406 .buf = i2c_data,
407 },
408 {
409 .addr = save_client->addr,
410 .flags = I2C_M_RD,
411 .len = 1,
412 .buf = i2c_buf,
413 },
414 };
415 struct i2c_msg msgs1[1] = {
416 {
417 .addr = save_client->addr,
418 .flags = 0,
419 .len = 2,
420 .buf = i2c_data,
421 },
422 };
423
424 i2c_data[0] = 0x09;
425 i2c_transfer(save_client->adapter, msgs0, 2);
426
427 i2c_data[0] = 0x09;
428 i2c_data[1] = 0x00;
429 i2c_transfer(save_client->adapter, msgs1, 1);
430}
431
432/**
433 * wdt_write:
434 * @file: file handle to the watchdog
435 * @buf: buffer to write (unused as data does not matter here
436 * @count: count of bytes
437 * @ppos: pointer to the position to write. No seeks allowed
438 *
439 * A write to a watchdog device is defined as a keepalive signal. Any
440 * write of data will do, as we we don't define content meaning.
441 */
442static ssize_t wdt_write(struct file *file, const char __user *buf,
443 size_t count, loff_t *ppos)
444{
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700445 if (count) {
446 wdt_ping();
447 return 1;
448 }
449 return 0;
450}
451
452static ssize_t wdt_read(struct file *file, char __user *buf,
453 size_t count, loff_t *ppos)
454{
455 return 0;
456}
457
458/**
459 * wdt_ioctl:
460 * @inode: inode of the device
461 * @file: file handle to the device
462 * @cmd: watchdog command
463 * @arg: argument pointer
464 *
465 * The watchdog API defines a common set of functions for all watchdogs
466 * according to their available features. We only actually usefully support
467 * querying capabilities and current status.
468 */
Arnd Bergmann55929332010-04-27 00:24:05 +0200469static int wdt_ioctl(struct file *file, unsigned int cmd,
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700470 unsigned long arg)
471{
472 int new_margin, rv;
473 static struct watchdog_info ident = {
474 .options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING |
475 WDIOF_SETTIMEOUT,
476 .firmware_version = 1,
477 .identity = "M41T80 WTD"
478 };
479
480 switch (cmd) {
481 case WDIOC_GETSUPPORT:
482 return copy_to_user((struct watchdog_info __user *)arg, &ident,
483 sizeof(ident)) ? -EFAULT : 0;
484
485 case WDIOC_GETSTATUS:
486 case WDIOC_GETBOOTSTATUS:
487 return put_user(boot_flag, (int __user *)arg);
488 case WDIOC_KEEPALIVE:
489 wdt_ping();
490 return 0;
491 case WDIOC_SETTIMEOUT:
492 if (get_user(new_margin, (int __user *)arg))
493 return -EFAULT;
494 /* Arbitrary, can't find the card's limits */
495 if (new_margin < 1 || new_margin > 124)
496 return -EINVAL;
497 wdt_margin = new_margin;
498 wdt_ping();
499 /* Fall */
500 case WDIOC_GETTIMEOUT:
501 return put_user(wdt_margin, (int __user *)arg);
502
503 case WDIOC_SETOPTIONS:
504 if (copy_from_user(&rv, (int __user *)arg, sizeof(int)))
505 return -EFAULT;
506
507 if (rv & WDIOS_DISABLECARD) {
Maciej W. Rozycki4c228db2008-07-23 21:30:32 -0700508 pr_info("rtc-m41t80: disable watchdog\n");
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700509 wdt_disable();
510 }
511
512 if (rv & WDIOS_ENABLECARD) {
Maciej W. Rozycki4c228db2008-07-23 21:30:32 -0700513 pr_info("rtc-m41t80: enable watchdog\n");
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700514 wdt_ping();
515 }
516
517 return -EINVAL;
518 }
519 return -ENOTTY;
520}
521
Arnd Bergmann55929332010-04-27 00:24:05 +0200522static long wdt_unlocked_ioctl(struct file *file, unsigned int cmd,
523 unsigned long arg)
524{
525 int ret;
526
Arnd Bergmann613655f2010-06-02 14:28:52 +0200527 mutex_lock(&m41t80_rtc_mutex);
Arnd Bergmann55929332010-04-27 00:24:05 +0200528 ret = wdt_ioctl(file, cmd, arg);
Arnd Bergmann613655f2010-06-02 14:28:52 +0200529 mutex_unlock(&m41t80_rtc_mutex);
Arnd Bergmann55929332010-04-27 00:24:05 +0200530
531 return ret;
532}
533
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700534/**
535 * wdt_open:
536 * @inode: inode of device
537 * @file: file handle to device
538 *
539 */
540static int wdt_open(struct inode *inode, struct file *file)
541{
542 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
Arnd Bergmann613655f2010-06-02 14:28:52 +0200543 mutex_lock(&m41t80_rtc_mutex);
Arnd Bergmann41012732008-05-20 19:16:39 +0200544 if (test_and_set_bit(0, &wdt_is_open)) {
Arnd Bergmann613655f2010-06-02 14:28:52 +0200545 mutex_unlock(&m41t80_rtc_mutex);
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700546 return -EBUSY;
Arnd Bergmann41012732008-05-20 19:16:39 +0200547 }
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700548 /*
549 * Activate
550 */
551 wdt_is_open = 1;
Arnd Bergmann613655f2010-06-02 14:28:52 +0200552 mutex_unlock(&m41t80_rtc_mutex);
Jan Blunck09eeb1f2010-05-26 14:44:47 -0700553 return nonseekable_open(inode, file);
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700554 }
555 return -ENODEV;
556}
557
558/**
559 * wdt_close:
560 * @inode: inode to board
561 * @file: file handle to board
562 *
563 */
564static int wdt_release(struct inode *inode, struct file *file)
565{
566 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR)
567 clear_bit(0, &wdt_is_open);
568 return 0;
569}
570
571/**
572 * notify_sys:
573 * @this: our notifier block
574 * @code: the event being reported
575 * @unused: unused
576 *
577 * Our notifier is called on system shutdowns. We want to turn the card
578 * off at reboot otherwise the machine will reboot again during memory
579 * test or worse yet during the following fsck. This would suck, in fact
580 * trust me - if it happens it does suck.
581 */
582static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
583 void *unused)
584{
585 if (code == SYS_DOWN || code == SYS_HALT)
586 /* Disable Watchdog */
587 wdt_disable();
588 return NOTIFY_DONE;
589}
590
591static const struct file_operations wdt_fops = {
592 .owner = THIS_MODULE,
593 .read = wdt_read,
Arnd Bergmann55929332010-04-27 00:24:05 +0200594 .unlocked_ioctl = wdt_unlocked_ioctl,
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700595 .write = wdt_write,
596 .open = wdt_open,
597 .release = wdt_release,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200598 .llseek = no_llseek,
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700599};
600
601static struct miscdevice wdt_dev = {
602 .minor = WATCHDOG_MINOR,
603 .name = "watchdog",
604 .fops = &wdt_fops,
605};
606
607/*
608 * The WDT card needs to learn about soft shutdowns in order to
609 * turn the timebomb registers off.
610 */
611static struct notifier_block wdt_notifier = {
612 .notifier_call = wdt_notify_sys,
613};
614#endif /* CONFIG_RTC_DRV_M41T80_WDT */
615
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700616/*
617 *****************************************************************************
618 *
619 * Driver Interface
620 *
621 *****************************************************************************
622 */
Jean Delvared2653e92008-04-29 23:11:39 +0200623static int m41t80_probe(struct i2c_client *client,
624 const struct i2c_device_id *id)
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700625{
Jean Delvare3760f732008-04-29 23:11:40 +0200626 int rc = 0;
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700627 struct rtc_device *rtc = NULL;
628 struct rtc_time tm;
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700629 struct m41t80_data *clientdata = NULL;
630
631 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C
632 | I2C_FUNC_SMBUS_BYTE_DATA)) {
633 rc = -ENODEV;
634 goto exit;
635 }
636
637 dev_info(&client->dev,
638 "chip found, driver version " DRV_VERSION "\n");
639
Jingoo Han4ebabb72013-04-29 16:20:42 -0700640 clientdata = devm_kzalloc(&client->dev, sizeof(*clientdata),
641 GFP_KERNEL);
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700642 if (!clientdata) {
643 rc = -ENOMEM;
644 goto exit;
645 }
646
John Stultza015dbc2011-05-06 17:24:27 -0700647 clientdata->features = id->driver_data;
648 i2c_set_clientdata(client, clientdata);
649
Jingoo Han4ebabb72013-04-29 16:20:42 -0700650 rtc = devm_rtc_device_register(&client->dev, client->name,
651 &m41t80_rtc_ops, THIS_MODULE);
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700652 if (IS_ERR(rtc)) {
653 rc = PTR_ERR(rtc);
654 rtc = NULL;
655 goto exit;
656 }
657
658 clientdata->rtc = rtc;
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700659
660 /* Make sure HT (Halt Update) bit is cleared */
661 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR);
662 if (rc < 0)
663 goto ht_err;
664
665 if (rc & M41T80_ALHOUR_HT) {
Jean Delvare3760f732008-04-29 23:11:40 +0200666 if (clientdata->features & M41T80_FEATURE_HT) {
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700667 m41t80_get_datetime(client, &tm);
668 dev_info(&client->dev, "HT bit was set!\n");
669 dev_info(&client->dev,
670 "Power Down at "
671 "%04i-%02i-%02i %02i:%02i:%02i\n",
672 tm.tm_year + 1900,
673 tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
674 tm.tm_min, tm.tm_sec);
675 }
676 if (i2c_smbus_write_byte_data(client,
677 M41T80_REG_ALARM_HOUR,
678 rc & ~M41T80_ALHOUR_HT) < 0)
679 goto ht_err;
680 }
681
682 /* Make sure ST (stop) bit is cleared */
683 rc = i2c_smbus_read_byte_data(client, M41T80_REG_SEC);
684 if (rc < 0)
685 goto st_err;
686
687 if (rc & M41T80_SEC_ST) {
688 if (i2c_smbus_write_byte_data(client, M41T80_REG_SEC,
689 rc & ~M41T80_SEC_ST) < 0)
690 goto st_err;
691 }
692
693 rc = m41t80_sysfs_register(&client->dev);
694 if (rc)
695 goto exit;
696
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700697#ifdef CONFIG_RTC_DRV_M41T80_WDT
Jean Delvare3760f732008-04-29 23:11:40 +0200698 if (clientdata->features & M41T80_FEATURE_HT) {
Maciej W. Rozycki417607d2008-05-12 14:02:35 -0700699 save_client = client;
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700700 rc = misc_register(&wdt_dev);
701 if (rc)
702 goto exit;
703 rc = register_reboot_notifier(&wdt_notifier);
704 if (rc) {
705 misc_deregister(&wdt_dev);
706 goto exit;
707 }
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700708 }
709#endif
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700710 return 0;
711
712st_err:
713 rc = -EIO;
714 dev_err(&client->dev, "Can't clear ST bit\n");
715 goto exit;
716ht_err:
717 rc = -EIO;
718 dev_err(&client->dev, "Can't clear HT bit\n");
719 goto exit;
720
721exit:
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700722 return rc;
723}
724
725static int m41t80_remove(struct i2c_client *client)
726{
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700727#ifdef CONFIG_RTC_DRV_M41T80_WDT
Jingoo Han4ebabb72013-04-29 16:20:42 -0700728 struct m41t80_data *clientdata = i2c_get_clientdata(client);
729
Jean Delvare3760f732008-04-29 23:11:40 +0200730 if (clientdata->features & M41T80_FEATURE_HT) {
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700731 misc_deregister(&wdt_dev);
732 unregister_reboot_notifier(&wdt_notifier);
733 }
734#endif
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700735
736 return 0;
737}
738
739static struct i2c_driver m41t80_driver = {
740 .driver = {
David Brownellafe1ab42007-08-22 14:01:27 -0700741 .name = "rtc-m41t80",
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700742 },
743 .probe = m41t80_probe,
744 .remove = m41t80_remove,
Jean Delvare3760f732008-04-29 23:11:40 +0200745 .id_table = m41t80_id,
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700746};
747
Axel Lin0abc9202012-03-23 15:02:31 -0700748module_i2c_driver(m41t80_driver);
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700749
750MODULE_AUTHOR("Alexander Bigga <ab@mycable.de>");
751MODULE_DESCRIPTION("ST Microelectronics M41T80 series RTC I2C Client Driver");
752MODULE_LICENSE("GPL");
753MODULE_VERSION(DRV_VERSION);