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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
John Stultz16380c12011-02-02 17:02:41 -0800216static int m41t80_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700217{
218 struct i2c_client *client = to_i2c_client(dev);
219 int rc;
220
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700221 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
222 if (rc < 0)
223 goto err;
John Stultz16380c12011-02-02 17:02:41 -0800224
225 if (enabled)
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700226 rc |= M41T80_ALMON_AFE;
John Stultz16380c12011-02-02 17:02:41 -0800227 else
228 rc &= ~M41T80_ALMON_AFE;
229
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700230 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, rc) < 0)
231 goto err;
John Stultz16380c12011-02-02 17:02:41 -0800232
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700233 return 0;
234err:
235 return -EIO;
236}
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700237
238static int m41t80_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *t)
239{
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[] = {
246 {
247 .addr = client->addr,
248 .flags = 0,
249 .len = 1,
250 .buf = dt_addr,
251 },
252 {
253 .addr = client->addr,
254 .flags = I2C_M_RD,
255 .len = M41T80_ALARM_REG_SIZE,
256 .buf = buf,
257 },
258 };
259 struct i2c_msg msgs[] = {
260 {
261 .addr = client->addr,
262 .flags = 0,
263 .len = 1 + M41T80_ALARM_REG_SIZE,
264 .buf = wbuf,
265 },
266 };
267
268 if (i2c_transfer(client->adapter, msgs_in, 2) < 0) {
269 dev_err(&client->dev, "read error\n");
270 return -EIO;
271 }
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;
277
278 wbuf[0] = M41T80_REG_ALARM_MON; /* offset into rtc's regs */
279 reg[M41T80_REG_ALARM_SEC] |= t->time.tm_sec >= 0 ?
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700280 bin2bcd(t->time.tm_sec) : 0x80;
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700281 reg[M41T80_REG_ALARM_MIN] |= t->time.tm_min >= 0 ?
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700282 bin2bcd(t->time.tm_min) : 0x80;
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700283 reg[M41T80_REG_ALARM_HOUR] |= t->time.tm_hour >= 0 ?
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700284 bin2bcd(t->time.tm_hour) : 0x80;
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700285 reg[M41T80_REG_ALARM_DAY] |= t->time.tm_mday >= 0 ?
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700286 bin2bcd(t->time.tm_mday) : 0x80;
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700287 if (t->time.tm_mon >= 0)
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700288 reg[M41T80_REG_ALARM_MON] |= bin2bcd(t->time.tm_mon + 1);
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700289 else
290 reg[M41T80_REG_ALARM_DAY] |= 0x40;
291
292 if (i2c_transfer(client->adapter, msgs, 1) != 1) {
293 dev_err(&client->dev, "write error\n");
294 return -EIO;
295 }
296
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;
303 }
304 }
305 return 0;
306}
307
308static int m41t80_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *t)
309{
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[] = {
315 {
316 .addr = client->addr,
317 .flags = 0,
318 .len = 1,
319 .buf = dt_addr,
320 },
321 {
322 .addr = client->addr,
323 .flags = I2C_M_RD,
324 .len = M41T80_ALARM_REG_SIZE + 1,
325 .buf = buf,
326 },
327 };
328
329 if (i2c_transfer(client->adapter, msgs, 2) < 0) {
330 dev_err(&client->dev, "read error\n");
331 return -EIO;
332 }
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))
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700339 t->time.tm_sec = bcd2bin(reg[M41T80_REG_ALARM_SEC] & 0x7f);
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700340 if (!(reg[M41T80_REG_ALARM_MIN] & 0x80))
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700341 t->time.tm_min = bcd2bin(reg[M41T80_REG_ALARM_MIN] & 0x7f);
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700342 if (!(reg[M41T80_REG_ALARM_HOUR] & 0x80))
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700343 t->time.tm_hour = bcd2bin(reg[M41T80_REG_ALARM_HOUR] & 0x3f);
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700344 if (!(reg[M41T80_REG_ALARM_DAY] & 0x80))
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700345 t->time.tm_mday = bcd2bin(reg[M41T80_REG_ALARM_DAY] & 0x3f);
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700346 if (!(reg[M41T80_REG_ALARM_DAY] & 0x40))
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700347 t->time.tm_mon = bcd2bin(reg[M41T80_REG_ALARM_MON] & 0x1f) - 1;
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700348 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);
Atsushi Nemoto408929b2010-09-09 16:37:56 -0700354 return 0;
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700355}
356
357static struct rtc_class_ops m41t80_rtc_ops = {
358 .read_time = m41t80_rtc_read_time,
359 .set_time = m41t80_rtc_set_time,
John Stultzc3b79772011-12-12 13:57:52 -0800360 /*
361 * XXX - m41t80 alarm functionality is reported broken.
362 * until it is fixed, don't register alarm functions.
363 *
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700364 .read_alarm = m41t80_rtc_read_alarm,
365 .set_alarm = m41t80_rtc_set_alarm,
John Stultzc3b79772011-12-12 13:57:52 -0800366 */
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700367 .proc = m41t80_rtc_proc,
John Stultzc3b79772011-12-12 13:57:52 -0800368 /*
369 * See above comment on broken alarm
370 *
John Stultz16380c12011-02-02 17:02:41 -0800371 .alarm_irq_enable = m41t80_rtc_alarm_irq_enable,
John Stultzc3b79772011-12-12 13:57:52 -0800372 */
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700373};
374
375#if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
376static ssize_t m41t80_sysfs_show_flags(struct device *dev,
377 struct device_attribute *attr, char *buf)
378{
379 struct i2c_client *client = to_i2c_client(dev);
380 int val;
381
382 val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
383 if (val < 0)
384 return -EIO;
385 return sprintf(buf, "%#x\n", val);
386}
387static DEVICE_ATTR(flags, S_IRUGO, m41t80_sysfs_show_flags, NULL);
388
389static ssize_t m41t80_sysfs_show_sqwfreq(struct device *dev,
390 struct device_attribute *attr, char *buf)
391{
392 struct i2c_client *client = to_i2c_client(dev);
Steven A. Falcod3a126f2008-10-15 22:03:07 -0700393 struct m41t80_data *clientdata = i2c_get_clientdata(client);
Daniel Glocknerf30281f2009-04-02 16:57:03 -0700394 int val, reg_sqw;
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700395
Steven A. Falcod3a126f2008-10-15 22:03:07 -0700396 if (!(clientdata->features & M41T80_FEATURE_SQ))
397 return -EINVAL;
398
Daniel Glocknerf30281f2009-04-02 16:57:03 -0700399 reg_sqw = M41T80_REG_SQW;
400 if (clientdata->features & M41T80_FEATURE_SQ_ALT)
401 reg_sqw = M41T80_REG_WDAY;
402 val = i2c_smbus_read_byte_data(client, reg_sqw);
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700403 if (val < 0)
404 return -EIO;
405 val = (val >> 4) & 0xf;
406 switch (val) {
407 case 0:
408 break;
409 case 1:
410 val = 32768;
411 break;
412 default:
413 val = 32768 >> val;
414 }
415 return sprintf(buf, "%d\n", val);
416}
417static ssize_t m41t80_sysfs_set_sqwfreq(struct device *dev,
418 struct device_attribute *attr,
419 const char *buf, size_t count)
420{
421 struct i2c_client *client = to_i2c_client(dev);
Steven A. Falcod3a126f2008-10-15 22:03:07 -0700422 struct m41t80_data *clientdata = i2c_get_clientdata(client);
Daniel Glocknerf30281f2009-04-02 16:57:03 -0700423 int almon, sqw, reg_sqw;
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700424 int val = simple_strtoul(buf, NULL, 0);
425
Steven A. Falcod3a126f2008-10-15 22:03:07 -0700426 if (!(clientdata->features & M41T80_FEATURE_SQ))
427 return -EINVAL;
428
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700429 if (val) {
430 if (!is_power_of_2(val))
431 return -EINVAL;
432 val = ilog2(val);
433 if (val == 15)
434 val = 1;
435 else if (val < 14)
436 val = 15 - val;
437 else
438 return -EINVAL;
439 }
440 /* disable SQW, set SQW frequency & re-enable */
441 almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
442 if (almon < 0)
443 return -EIO;
Daniel Glocknerf30281f2009-04-02 16:57:03 -0700444 reg_sqw = M41T80_REG_SQW;
445 if (clientdata->features & M41T80_FEATURE_SQ_ALT)
446 reg_sqw = M41T80_REG_WDAY;
447 sqw = i2c_smbus_read_byte_data(client, reg_sqw);
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700448 if (sqw < 0)
449 return -EIO;
450 sqw = (sqw & 0x0f) | (val << 4);
451 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
452 almon & ~M41T80_ALMON_SQWE) < 0 ||
Daniel Glocknerf30281f2009-04-02 16:57:03 -0700453 i2c_smbus_write_byte_data(client, reg_sqw, sqw) < 0)
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700454 return -EIO;
455 if (val && i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
456 almon | M41T80_ALMON_SQWE) < 0)
457 return -EIO;
458 return count;
459}
460static DEVICE_ATTR(sqwfreq, S_IRUGO | S_IWUSR,
461 m41t80_sysfs_show_sqwfreq, m41t80_sysfs_set_sqwfreq);
462
463static struct attribute *attrs[] = {
464 &dev_attr_flags.attr,
465 &dev_attr_sqwfreq.attr,
466 NULL,
467};
468static struct attribute_group attr_group = {
469 .attrs = attrs,
470};
471
472static int m41t80_sysfs_register(struct device *dev)
473{
474 return sysfs_create_group(&dev->kobj, &attr_group);
475}
476#else
477static int m41t80_sysfs_register(struct device *dev)
478{
479 return 0;
480}
481#endif
482
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700483#ifdef CONFIG_RTC_DRV_M41T80_WDT
484/*
485 *****************************************************************************
486 *
487 * Watchdog Driver
488 *
489 *****************************************************************************
490 */
491static struct i2c_client *save_client;
492
493/* Default margin */
494#define WD_TIMO 60 /* 1..31 seconds */
495
496static int wdt_margin = WD_TIMO;
497module_param(wdt_margin, int, 0);
498MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)");
499
500static unsigned long wdt_is_open;
501static int boot_flag;
502
503/**
504 * wdt_ping:
505 *
506 * Reload counter one with the watchdog timeout. We don't bother reloading
507 * the cascade counter.
508 */
509static void wdt_ping(void)
510{
511 unsigned char i2c_data[2];
512 struct i2c_msg msgs1[1] = {
513 {
514 .addr = save_client->addr,
515 .flags = 0,
516 .len = 2,
517 .buf = i2c_data,
518 },
519 };
Steven A. Falcod3a126f2008-10-15 22:03:07 -0700520 struct m41t80_data *clientdata = i2c_get_clientdata(save_client);
521
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700522 i2c_data[0] = 0x09; /* watchdog register */
523
524 if (wdt_margin > 31)
525 i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */
526 else
527 /*
528 * WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02)
529 */
530 i2c_data[1] = wdt_margin<<2 | 0x82;
531
Steven A. Falcod3a126f2008-10-15 22:03:07 -0700532 /*
533 * M41T65 has three bits for watchdog resolution. Don't set bit 7, as
534 * that would be an invalid resolution.
535 */
536 if (clientdata->features & M41T80_FEATURE_WD)
537 i2c_data[1] &= ~M41T80_WATCHDOG_RB2;
538
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700539 i2c_transfer(save_client->adapter, msgs1, 1);
540}
541
542/**
543 * wdt_disable:
544 *
545 * disables watchdog.
546 */
547static void wdt_disable(void)
548{
549 unsigned char i2c_data[2], i2c_buf[0x10];
550 struct i2c_msg msgs0[2] = {
551 {
552 .addr = save_client->addr,
553 .flags = 0,
554 .len = 1,
555 .buf = i2c_data,
556 },
557 {
558 .addr = save_client->addr,
559 .flags = I2C_M_RD,
560 .len = 1,
561 .buf = i2c_buf,
562 },
563 };
564 struct i2c_msg msgs1[1] = {
565 {
566 .addr = save_client->addr,
567 .flags = 0,
568 .len = 2,
569 .buf = i2c_data,
570 },
571 };
572
573 i2c_data[0] = 0x09;
574 i2c_transfer(save_client->adapter, msgs0, 2);
575
576 i2c_data[0] = 0x09;
577 i2c_data[1] = 0x00;
578 i2c_transfer(save_client->adapter, msgs1, 1);
579}
580
581/**
582 * wdt_write:
583 * @file: file handle to the watchdog
584 * @buf: buffer to write (unused as data does not matter here
585 * @count: count of bytes
586 * @ppos: pointer to the position to write. No seeks allowed
587 *
588 * A write to a watchdog device is defined as a keepalive signal. Any
589 * write of data will do, as we we don't define content meaning.
590 */
591static ssize_t wdt_write(struct file *file, const char __user *buf,
592 size_t count, loff_t *ppos)
593{
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700594 if (count) {
595 wdt_ping();
596 return 1;
597 }
598 return 0;
599}
600
601static ssize_t wdt_read(struct file *file, char __user *buf,
602 size_t count, loff_t *ppos)
603{
604 return 0;
605}
606
607/**
608 * wdt_ioctl:
609 * @inode: inode of the device
610 * @file: file handle to the device
611 * @cmd: watchdog command
612 * @arg: argument pointer
613 *
614 * The watchdog API defines a common set of functions for all watchdogs
615 * according to their available features. We only actually usefully support
616 * querying capabilities and current status.
617 */
Arnd Bergmann55929332010-04-27 00:24:05 +0200618static int wdt_ioctl(struct file *file, unsigned int cmd,
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700619 unsigned long arg)
620{
621 int new_margin, rv;
622 static struct watchdog_info ident = {
623 .options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING |
624 WDIOF_SETTIMEOUT,
625 .firmware_version = 1,
626 .identity = "M41T80 WTD"
627 };
628
629 switch (cmd) {
630 case WDIOC_GETSUPPORT:
631 return copy_to_user((struct watchdog_info __user *)arg, &ident,
632 sizeof(ident)) ? -EFAULT : 0;
633
634 case WDIOC_GETSTATUS:
635 case WDIOC_GETBOOTSTATUS:
636 return put_user(boot_flag, (int __user *)arg);
637 case WDIOC_KEEPALIVE:
638 wdt_ping();
639 return 0;
640 case WDIOC_SETTIMEOUT:
641 if (get_user(new_margin, (int __user *)arg))
642 return -EFAULT;
643 /* Arbitrary, can't find the card's limits */
644 if (new_margin < 1 || new_margin > 124)
645 return -EINVAL;
646 wdt_margin = new_margin;
647 wdt_ping();
648 /* Fall */
649 case WDIOC_GETTIMEOUT:
650 return put_user(wdt_margin, (int __user *)arg);
651
652 case WDIOC_SETOPTIONS:
653 if (copy_from_user(&rv, (int __user *)arg, sizeof(int)))
654 return -EFAULT;
655
656 if (rv & WDIOS_DISABLECARD) {
Maciej W. Rozycki4c228db2008-07-23 21:30:32 -0700657 pr_info("rtc-m41t80: disable watchdog\n");
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700658 wdt_disable();
659 }
660
661 if (rv & WDIOS_ENABLECARD) {
Maciej W. Rozycki4c228db2008-07-23 21:30:32 -0700662 pr_info("rtc-m41t80: enable watchdog\n");
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700663 wdt_ping();
664 }
665
666 return -EINVAL;
667 }
668 return -ENOTTY;
669}
670
Arnd Bergmann55929332010-04-27 00:24:05 +0200671static long wdt_unlocked_ioctl(struct file *file, unsigned int cmd,
672 unsigned long arg)
673{
674 int ret;
675
Arnd Bergmann613655f2010-06-02 14:28:52 +0200676 mutex_lock(&m41t80_rtc_mutex);
Arnd Bergmann55929332010-04-27 00:24:05 +0200677 ret = wdt_ioctl(file, cmd, arg);
Arnd Bergmann613655f2010-06-02 14:28:52 +0200678 mutex_unlock(&m41t80_rtc_mutex);
Arnd Bergmann55929332010-04-27 00:24:05 +0200679
680 return ret;
681}
682
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700683/**
684 * wdt_open:
685 * @inode: inode of device
686 * @file: file handle to device
687 *
688 */
689static int wdt_open(struct inode *inode, struct file *file)
690{
691 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
Arnd Bergmann613655f2010-06-02 14:28:52 +0200692 mutex_lock(&m41t80_rtc_mutex);
Arnd Bergmann41012732008-05-20 19:16:39 +0200693 if (test_and_set_bit(0, &wdt_is_open)) {
Arnd Bergmann613655f2010-06-02 14:28:52 +0200694 mutex_unlock(&m41t80_rtc_mutex);
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700695 return -EBUSY;
Arnd Bergmann41012732008-05-20 19:16:39 +0200696 }
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700697 /*
698 * Activate
699 */
700 wdt_is_open = 1;
Arnd Bergmann613655f2010-06-02 14:28:52 +0200701 mutex_unlock(&m41t80_rtc_mutex);
Jan Blunck09eeb1f2010-05-26 14:44:47 -0700702 return nonseekable_open(inode, file);
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700703 }
704 return -ENODEV;
705}
706
707/**
708 * wdt_close:
709 * @inode: inode to board
710 * @file: file handle to board
711 *
712 */
713static int wdt_release(struct inode *inode, struct file *file)
714{
715 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR)
716 clear_bit(0, &wdt_is_open);
717 return 0;
718}
719
720/**
721 * notify_sys:
722 * @this: our notifier block
723 * @code: the event being reported
724 * @unused: unused
725 *
726 * Our notifier is called on system shutdowns. We want to turn the card
727 * off at reboot otherwise the machine will reboot again during memory
728 * test or worse yet during the following fsck. This would suck, in fact
729 * trust me - if it happens it does suck.
730 */
731static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
732 void *unused)
733{
734 if (code == SYS_DOWN || code == SYS_HALT)
735 /* Disable Watchdog */
736 wdt_disable();
737 return NOTIFY_DONE;
738}
739
740static const struct file_operations wdt_fops = {
741 .owner = THIS_MODULE,
742 .read = wdt_read,
Arnd Bergmann55929332010-04-27 00:24:05 +0200743 .unlocked_ioctl = wdt_unlocked_ioctl,
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700744 .write = wdt_write,
745 .open = wdt_open,
746 .release = wdt_release,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200747 .llseek = no_llseek,
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700748};
749
750static struct miscdevice wdt_dev = {
751 .minor = WATCHDOG_MINOR,
752 .name = "watchdog",
753 .fops = &wdt_fops,
754};
755
756/*
757 * The WDT card needs to learn about soft shutdowns in order to
758 * turn the timebomb registers off.
759 */
760static struct notifier_block wdt_notifier = {
761 .notifier_call = wdt_notify_sys,
762};
763#endif /* CONFIG_RTC_DRV_M41T80_WDT */
764
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700765/*
766 *****************************************************************************
767 *
768 * Driver Interface
769 *
770 *****************************************************************************
771 */
Jean Delvared2653e92008-04-29 23:11:39 +0200772static int m41t80_probe(struct i2c_client *client,
773 const struct i2c_device_id *id)
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700774{
Jean Delvare3760f732008-04-29 23:11:40 +0200775 int rc = 0;
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700776 struct rtc_device *rtc = NULL;
777 struct rtc_time tm;
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700778 struct m41t80_data *clientdata = NULL;
779
780 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C
781 | I2C_FUNC_SMBUS_BYTE_DATA)) {
782 rc = -ENODEV;
783 goto exit;
784 }
785
786 dev_info(&client->dev,
787 "chip found, driver version " DRV_VERSION "\n");
788
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700789 clientdata = kzalloc(sizeof(*clientdata), GFP_KERNEL);
790 if (!clientdata) {
791 rc = -ENOMEM;
792 goto exit;
793 }
794
John Stultza015dbc2011-05-06 17:24:27 -0700795 clientdata->features = id->driver_data;
796 i2c_set_clientdata(client, clientdata);
797
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700798 rtc = rtc_device_register(client->name, &client->dev,
799 &m41t80_rtc_ops, THIS_MODULE);
800 if (IS_ERR(rtc)) {
801 rc = PTR_ERR(rtc);
802 rtc = NULL;
803 goto exit;
804 }
805
806 clientdata->rtc = rtc;
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700807
808 /* Make sure HT (Halt Update) bit is cleared */
809 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR);
810 if (rc < 0)
811 goto ht_err;
812
813 if (rc & M41T80_ALHOUR_HT) {
Jean Delvare3760f732008-04-29 23:11:40 +0200814 if (clientdata->features & M41T80_FEATURE_HT) {
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700815 m41t80_get_datetime(client, &tm);
816 dev_info(&client->dev, "HT bit was set!\n");
817 dev_info(&client->dev,
818 "Power Down at "
819 "%04i-%02i-%02i %02i:%02i:%02i\n",
820 tm.tm_year + 1900,
821 tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
822 tm.tm_min, tm.tm_sec);
823 }
824 if (i2c_smbus_write_byte_data(client,
825 M41T80_REG_ALARM_HOUR,
826 rc & ~M41T80_ALHOUR_HT) < 0)
827 goto ht_err;
828 }
829
830 /* Make sure ST (stop) bit is cleared */
831 rc = i2c_smbus_read_byte_data(client, M41T80_REG_SEC);
832 if (rc < 0)
833 goto st_err;
834
835 if (rc & M41T80_SEC_ST) {
836 if (i2c_smbus_write_byte_data(client, M41T80_REG_SEC,
837 rc & ~M41T80_SEC_ST) < 0)
838 goto st_err;
839 }
840
841 rc = m41t80_sysfs_register(&client->dev);
842 if (rc)
843 goto exit;
844
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700845#ifdef CONFIG_RTC_DRV_M41T80_WDT
Jean Delvare3760f732008-04-29 23:11:40 +0200846 if (clientdata->features & M41T80_FEATURE_HT) {
Maciej W. Rozycki417607d2008-05-12 14:02:35 -0700847 save_client = client;
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700848 rc = misc_register(&wdt_dev);
849 if (rc)
850 goto exit;
851 rc = register_reboot_notifier(&wdt_notifier);
852 if (rc) {
853 misc_deregister(&wdt_dev);
854 goto exit;
855 }
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700856 }
857#endif
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700858 return 0;
859
860st_err:
861 rc = -EIO;
862 dev_err(&client->dev, "Can't clear ST bit\n");
863 goto exit;
864ht_err:
865 rc = -EIO;
866 dev_err(&client->dev, "Can't clear HT bit\n");
867 goto exit;
868
869exit:
870 if (rtc)
871 rtc_device_unregister(rtc);
872 kfree(clientdata);
873 return rc;
874}
875
876static int m41t80_remove(struct i2c_client *client)
877{
878 struct m41t80_data *clientdata = i2c_get_clientdata(client);
879 struct rtc_device *rtc = clientdata->rtc;
880
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700881#ifdef CONFIG_RTC_DRV_M41T80_WDT
Jean Delvare3760f732008-04-29 23:11:40 +0200882 if (clientdata->features & M41T80_FEATURE_HT) {
Atsushi Nemoto617780d2007-07-17 04:05:04 -0700883 misc_deregister(&wdt_dev);
884 unregister_reboot_notifier(&wdt_notifier);
885 }
886#endif
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700887 if (rtc)
888 rtc_device_unregister(rtc);
889 kfree(clientdata);
890
891 return 0;
892}
893
894static struct i2c_driver m41t80_driver = {
895 .driver = {
David Brownellafe1ab42007-08-22 14:01:27 -0700896 .name = "rtc-m41t80",
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700897 },
898 .probe = m41t80_probe,
899 .remove = m41t80_remove,
Jean Delvare3760f732008-04-29 23:11:40 +0200900 .id_table = m41t80_id,
Atsushi Nemotocaaff562007-07-17 04:05:02 -0700901};
902
903static int __init m41t80_rtc_init(void)
904{
905 return i2c_add_driver(&m41t80_driver);
906}
907
908static void __exit m41t80_rtc_exit(void)
909{
910 i2c_del_driver(&m41t80_driver);
911}
912
913MODULE_AUTHOR("Alexander Bigga <ab@mycable.de>");
914MODULE_DESCRIPTION("ST Microelectronics M41T80 series RTC I2C Client Driver");
915MODULE_LICENSE("GPL");
916MODULE_VERSION(DRV_VERSION);
917
918module_init(m41t80_rtc_init);
919module_exit(m41t80_rtc_exit);