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caaff562 AN |
1 | /* |
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 | ||
16 | #include <linux/module.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/string.h> | |
20 | #include <linux/i2c.h> | |
21 | #include <linux/rtc.h> | |
22 | #include <linux/bcd.h> | |
617780d2 AN |
23 | #ifdef CONFIG_RTC_DRV_M41T80_WDT |
24 | #include <linux/miscdevice.h> | |
25 | #include <linux/watchdog.h> | |
26 | #include <linux/reboot.h> | |
27 | #include <linux/fs.h> | |
28 | #include <linux/ioctl.h> | |
29 | #endif | |
caaff562 AN |
30 | |
31 | #define M41T80_REG_SSEC 0 | |
32 | #define M41T80_REG_SEC 1 | |
33 | #define M41T80_REG_MIN 2 | |
34 | #define M41T80_REG_HOUR 3 | |
35 | #define M41T80_REG_WDAY 4 | |
36 | #define M41T80_REG_DAY 5 | |
37 | #define M41T80_REG_MON 6 | |
38 | #define M41T80_REG_YEAR 7 | |
39 | #define M41T80_REG_ALARM_MON 0xa | |
40 | #define M41T80_REG_ALARM_DAY 0xb | |
41 | #define M41T80_REG_ALARM_HOUR 0xc | |
42 | #define M41T80_REG_ALARM_MIN 0xd | |
43 | #define M41T80_REG_ALARM_SEC 0xe | |
44 | #define M41T80_REG_FLAGS 0xf | |
45 | #define M41T80_REG_SQW 0x13 | |
46 | ||
47 | #define M41T80_DATETIME_REG_SIZE (M41T80_REG_YEAR + 1) | |
48 | #define M41T80_ALARM_REG_SIZE \ | |
49 | (M41T80_REG_ALARM_SEC + 1 - M41T80_REG_ALARM_MON) | |
50 | ||
51 | #define M41T80_SEC_ST (1 << 7) /* ST: Stop Bit */ | |
52 | #define M41T80_ALMON_AFE (1 << 7) /* AFE: AF Enable Bit */ | |
53 | #define M41T80_ALMON_SQWE (1 << 6) /* SQWE: SQW Enable Bit */ | |
54 | #define M41T80_ALHOUR_HT (1 << 6) /* HT: Halt Update Bit */ | |
55 | #define M41T80_FLAGS_AF (1 << 6) /* AF: Alarm Flag Bit */ | |
56 | #define M41T80_FLAGS_BATT_LOW (1 << 4) /* BL: Battery Low Bit */ | |
57 | ||
58 | #define M41T80_FEATURE_HT (1 << 0) | |
59 | #define M41T80_FEATURE_BL (1 << 1) | |
60 | ||
61 | #define DRV_VERSION "0.05" | |
62 | ||
63 | struct m41t80_chip_info { | |
64 | const char *name; | |
65 | u8 features; | |
66 | }; | |
67 | ||
68 | static const struct m41t80_chip_info m41t80_chip_info_tbl[] = { | |
69 | { | |
70 | .name = "m41t80", | |
71 | .features = 0, | |
72 | }, | |
73 | { | |
74 | .name = "m41t81", | |
75 | .features = M41T80_FEATURE_HT, | |
76 | }, | |
77 | { | |
78 | .name = "m41t81s", | |
79 | .features = M41T80_FEATURE_HT | M41T80_FEATURE_BL, | |
80 | }, | |
81 | { | |
82 | .name = "m41t82", | |
83 | .features = M41T80_FEATURE_HT | M41T80_FEATURE_BL, | |
84 | }, | |
85 | { | |
86 | .name = "m41t83", | |
87 | .features = M41T80_FEATURE_HT | M41T80_FEATURE_BL, | |
88 | }, | |
89 | { | |
90 | .name = "m41st84", | |
91 | .features = M41T80_FEATURE_HT | M41T80_FEATURE_BL, | |
92 | }, | |
93 | { | |
94 | .name = "m41st85", | |
95 | .features = M41T80_FEATURE_HT | M41T80_FEATURE_BL, | |
96 | }, | |
97 | { | |
98 | .name = "m41st87", | |
99 | .features = M41T80_FEATURE_HT | M41T80_FEATURE_BL, | |
100 | }, | |
101 | }; | |
102 | ||
103 | struct m41t80_data { | |
104 | const struct m41t80_chip_info *chip; | |
105 | struct rtc_device *rtc; | |
106 | }; | |
107 | ||
108 | static int m41t80_get_datetime(struct i2c_client *client, | |
109 | struct rtc_time *tm) | |
110 | { | |
111 | u8 buf[M41T80_DATETIME_REG_SIZE], dt_addr[1] = { M41T80_REG_SEC }; | |
112 | struct i2c_msg msgs[] = { | |
113 | { | |
114 | .addr = client->addr, | |
115 | .flags = 0, | |
116 | .len = 1, | |
117 | .buf = dt_addr, | |
118 | }, | |
119 | { | |
120 | .addr = client->addr, | |
121 | .flags = I2C_M_RD, | |
122 | .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC, | |
123 | .buf = buf + M41T80_REG_SEC, | |
124 | }, | |
125 | }; | |
126 | ||
127 | if (i2c_transfer(client->adapter, msgs, 2) < 0) { | |
128 | dev_err(&client->dev, "read error\n"); | |
129 | return -EIO; | |
130 | } | |
131 | ||
132 | tm->tm_sec = BCD2BIN(buf[M41T80_REG_SEC] & 0x7f); | |
133 | tm->tm_min = BCD2BIN(buf[M41T80_REG_MIN] & 0x7f); | |
134 | tm->tm_hour = BCD2BIN(buf[M41T80_REG_HOUR] & 0x3f); | |
135 | tm->tm_mday = BCD2BIN(buf[M41T80_REG_DAY] & 0x3f); | |
136 | tm->tm_wday = buf[M41T80_REG_WDAY] & 0x07; | |
137 | tm->tm_mon = BCD2BIN(buf[M41T80_REG_MON] & 0x1f) - 1; | |
138 | ||
139 | /* assume 20YY not 19YY, and ignore the Century Bit */ | |
140 | tm->tm_year = BCD2BIN(buf[M41T80_REG_YEAR]) + 100; | |
141 | return 0; | |
142 | } | |
143 | ||
144 | /* Sets the given date and time to the real time clock. */ | |
145 | static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm) | |
146 | { | |
147 | u8 wbuf[1 + M41T80_DATETIME_REG_SIZE]; | |
148 | u8 *buf = &wbuf[1]; | |
149 | u8 dt_addr[1] = { M41T80_REG_SEC }; | |
150 | struct i2c_msg msgs_in[] = { | |
151 | { | |
152 | .addr = client->addr, | |
153 | .flags = 0, | |
154 | .len = 1, | |
155 | .buf = dt_addr, | |
156 | }, | |
157 | { | |
158 | .addr = client->addr, | |
159 | .flags = I2C_M_RD, | |
160 | .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC, | |
161 | .buf = buf + M41T80_REG_SEC, | |
162 | }, | |
163 | }; | |
164 | struct i2c_msg msgs[] = { | |
165 | { | |
166 | .addr = client->addr, | |
167 | .flags = 0, | |
168 | .len = 1 + M41T80_DATETIME_REG_SIZE, | |
169 | .buf = wbuf, | |
170 | }, | |
171 | }; | |
172 | ||
173 | /* Read current reg values into buf[1..7] */ | |
174 | if (i2c_transfer(client->adapter, msgs_in, 2) < 0) { | |
175 | dev_err(&client->dev, "read error\n"); | |
176 | return -EIO; | |
177 | } | |
178 | ||
179 | wbuf[0] = 0; /* offset into rtc's regs */ | |
180 | /* Merge time-data and register flags into buf[0..7] */ | |
181 | buf[M41T80_REG_SSEC] = 0; | |
182 | buf[M41T80_REG_SEC] = | |
183 | BIN2BCD(tm->tm_sec) | (buf[M41T80_REG_SEC] & ~0x7f); | |
184 | buf[M41T80_REG_MIN] = | |
185 | BIN2BCD(tm->tm_min) | (buf[M41T80_REG_MIN] & ~0x7f); | |
186 | buf[M41T80_REG_HOUR] = | |
187 | BIN2BCD(tm->tm_hour) | (buf[M41T80_REG_HOUR] & ~0x3f) ; | |
188 | buf[M41T80_REG_WDAY] = | |
189 | (tm->tm_wday & 0x07) | (buf[M41T80_REG_WDAY] & ~0x07); | |
190 | buf[M41T80_REG_DAY] = | |
191 | BIN2BCD(tm->tm_mday) | (buf[M41T80_REG_DAY] & ~0x3f); | |
192 | buf[M41T80_REG_MON] = | |
193 | BIN2BCD(tm->tm_mon + 1) | (buf[M41T80_REG_MON] & ~0x1f); | |
194 | /* assume 20YY not 19YY */ | |
195 | buf[M41T80_REG_YEAR] = BIN2BCD(tm->tm_year % 100); | |
196 | ||
197 | if (i2c_transfer(client->adapter, msgs, 1) != 1) { | |
198 | dev_err(&client->dev, "write error\n"); | |
199 | return -EIO; | |
200 | } | |
201 | return 0; | |
202 | } | |
203 | ||
204 | #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE) | |
205 | static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq) | |
206 | { | |
207 | struct i2c_client *client = to_i2c_client(dev); | |
208 | struct m41t80_data *clientdata = i2c_get_clientdata(client); | |
209 | u8 reg; | |
210 | ||
211 | if (clientdata->chip->features & M41T80_FEATURE_BL) { | |
212 | reg = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); | |
213 | seq_printf(seq, "battery\t\t: %s\n", | |
214 | (reg & M41T80_FLAGS_BATT_LOW) ? "exhausted" : "ok"); | |
215 | } | |
216 | return 0; | |
217 | } | |
218 | #else | |
219 | #define m41t80_rtc_proc NULL | |
220 | #endif | |
221 | ||
222 | static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
223 | { | |
224 | return m41t80_get_datetime(to_i2c_client(dev), tm); | |
225 | } | |
226 | ||
227 | static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
228 | { | |
229 | return m41t80_set_datetime(to_i2c_client(dev), tm); | |
230 | } | |
231 | ||
232 | #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE) | |
233 | static int | |
234 | m41t80_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) | |
235 | { | |
236 | struct i2c_client *client = to_i2c_client(dev); | |
237 | int rc; | |
238 | ||
239 | switch (cmd) { | |
240 | case RTC_AIE_OFF: | |
241 | case RTC_AIE_ON: | |
242 | break; | |
243 | default: | |
244 | return -ENOIOCTLCMD; | |
245 | } | |
246 | ||
247 | rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON); | |
248 | if (rc < 0) | |
249 | goto err; | |
250 | switch (cmd) { | |
251 | case RTC_AIE_OFF: | |
252 | rc &= ~M41T80_ALMON_AFE; | |
253 | break; | |
254 | case RTC_AIE_ON: | |
255 | rc |= M41T80_ALMON_AFE; | |
256 | break; | |
257 | } | |
258 | if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, rc) < 0) | |
259 | goto err; | |
260 | return 0; | |
261 | err: | |
262 | return -EIO; | |
263 | } | |
264 | #else | |
265 | #define m41t80_rtc_ioctl NULL | |
266 | #endif | |
267 | ||
268 | static int m41t80_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *t) | |
269 | { | |
270 | struct i2c_client *client = to_i2c_client(dev); | |
271 | u8 wbuf[1 + M41T80_ALARM_REG_SIZE]; | |
272 | u8 *buf = &wbuf[1]; | |
273 | u8 *reg = buf - M41T80_REG_ALARM_MON; | |
274 | u8 dt_addr[1] = { M41T80_REG_ALARM_MON }; | |
275 | struct i2c_msg msgs_in[] = { | |
276 | { | |
277 | .addr = client->addr, | |
278 | .flags = 0, | |
279 | .len = 1, | |
280 | .buf = dt_addr, | |
281 | }, | |
282 | { | |
283 | .addr = client->addr, | |
284 | .flags = I2C_M_RD, | |
285 | .len = M41T80_ALARM_REG_SIZE, | |
286 | .buf = buf, | |
287 | }, | |
288 | }; | |
289 | struct i2c_msg msgs[] = { | |
290 | { | |
291 | .addr = client->addr, | |
292 | .flags = 0, | |
293 | .len = 1 + M41T80_ALARM_REG_SIZE, | |
294 | .buf = wbuf, | |
295 | }, | |
296 | }; | |
297 | ||
298 | if (i2c_transfer(client->adapter, msgs_in, 2) < 0) { | |
299 | dev_err(&client->dev, "read error\n"); | |
300 | return -EIO; | |
301 | } | |
302 | reg[M41T80_REG_ALARM_MON] &= ~(0x1f | M41T80_ALMON_AFE); | |
303 | reg[M41T80_REG_ALARM_DAY] = 0; | |
304 | reg[M41T80_REG_ALARM_HOUR] &= ~(0x3f | 0x80); | |
305 | reg[M41T80_REG_ALARM_MIN] = 0; | |
306 | reg[M41T80_REG_ALARM_SEC] = 0; | |
307 | ||
308 | wbuf[0] = M41T80_REG_ALARM_MON; /* offset into rtc's regs */ | |
309 | reg[M41T80_REG_ALARM_SEC] |= t->time.tm_sec >= 0 ? | |
310 | BIN2BCD(t->time.tm_sec) : 0x80; | |
311 | reg[M41T80_REG_ALARM_MIN] |= t->time.tm_min >= 0 ? | |
312 | BIN2BCD(t->time.tm_min) : 0x80; | |
313 | reg[M41T80_REG_ALARM_HOUR] |= t->time.tm_hour >= 0 ? | |
314 | BIN2BCD(t->time.tm_hour) : 0x80; | |
315 | reg[M41T80_REG_ALARM_DAY] |= t->time.tm_mday >= 0 ? | |
316 | BIN2BCD(t->time.tm_mday) : 0x80; | |
317 | if (t->time.tm_mon >= 0) | |
318 | reg[M41T80_REG_ALARM_MON] |= BIN2BCD(t->time.tm_mon + 1); | |
319 | else | |
320 | reg[M41T80_REG_ALARM_DAY] |= 0x40; | |
321 | ||
322 | if (i2c_transfer(client->adapter, msgs, 1) != 1) { | |
323 | dev_err(&client->dev, "write error\n"); | |
324 | return -EIO; | |
325 | } | |
326 | ||
327 | if (t->enabled) { | |
328 | reg[M41T80_REG_ALARM_MON] |= M41T80_ALMON_AFE; | |
329 | if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, | |
330 | reg[M41T80_REG_ALARM_MON]) < 0) { | |
331 | dev_err(&client->dev, "write error\n"); | |
332 | return -EIO; | |
333 | } | |
334 | } | |
335 | return 0; | |
336 | } | |
337 | ||
338 | static int m41t80_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *t) | |
339 | { | |
340 | struct i2c_client *client = to_i2c_client(dev); | |
341 | u8 buf[M41T80_ALARM_REG_SIZE + 1]; /* all alarm regs and flags */ | |
342 | u8 dt_addr[1] = { M41T80_REG_ALARM_MON }; | |
343 | u8 *reg = buf - M41T80_REG_ALARM_MON; | |
344 | struct i2c_msg msgs[] = { | |
345 | { | |
346 | .addr = client->addr, | |
347 | .flags = 0, | |
348 | .len = 1, | |
349 | .buf = dt_addr, | |
350 | }, | |
351 | { | |
352 | .addr = client->addr, | |
353 | .flags = I2C_M_RD, | |
354 | .len = M41T80_ALARM_REG_SIZE + 1, | |
355 | .buf = buf, | |
356 | }, | |
357 | }; | |
358 | ||
359 | if (i2c_transfer(client->adapter, msgs, 2) < 0) { | |
360 | dev_err(&client->dev, "read error\n"); | |
361 | return -EIO; | |
362 | } | |
363 | t->time.tm_sec = -1; | |
364 | t->time.tm_min = -1; | |
365 | t->time.tm_hour = -1; | |
366 | t->time.tm_mday = -1; | |
367 | t->time.tm_mon = -1; | |
368 | if (!(reg[M41T80_REG_ALARM_SEC] & 0x80)) | |
369 | t->time.tm_sec = BCD2BIN(reg[M41T80_REG_ALARM_SEC] & 0x7f); | |
370 | if (!(reg[M41T80_REG_ALARM_MIN] & 0x80)) | |
371 | t->time.tm_min = BCD2BIN(reg[M41T80_REG_ALARM_MIN] & 0x7f); | |
372 | if (!(reg[M41T80_REG_ALARM_HOUR] & 0x80)) | |
373 | t->time.tm_hour = BCD2BIN(reg[M41T80_REG_ALARM_HOUR] & 0x3f); | |
374 | if (!(reg[M41T80_REG_ALARM_DAY] & 0x80)) | |
375 | t->time.tm_mday = BCD2BIN(reg[M41T80_REG_ALARM_DAY] & 0x3f); | |
376 | if (!(reg[M41T80_REG_ALARM_DAY] & 0x40)) | |
377 | t->time.tm_mon = BCD2BIN(reg[M41T80_REG_ALARM_MON] & 0x1f) - 1; | |
378 | t->time.tm_year = -1; | |
379 | t->time.tm_wday = -1; | |
380 | t->time.tm_yday = -1; | |
381 | t->time.tm_isdst = -1; | |
382 | t->enabled = !!(reg[M41T80_REG_ALARM_MON] & M41T80_ALMON_AFE); | |
383 | t->pending = !!(reg[M41T80_REG_FLAGS] & M41T80_FLAGS_AF); | |
384 | return 0; | |
385 | } | |
386 | ||
387 | static struct rtc_class_ops m41t80_rtc_ops = { | |
388 | .read_time = m41t80_rtc_read_time, | |
389 | .set_time = m41t80_rtc_set_time, | |
390 | .read_alarm = m41t80_rtc_read_alarm, | |
391 | .set_alarm = m41t80_rtc_set_alarm, | |
392 | .proc = m41t80_rtc_proc, | |
393 | .ioctl = m41t80_rtc_ioctl, | |
394 | }; | |
395 | ||
396 | #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE) | |
397 | static ssize_t m41t80_sysfs_show_flags(struct device *dev, | |
398 | struct device_attribute *attr, char *buf) | |
399 | { | |
400 | struct i2c_client *client = to_i2c_client(dev); | |
401 | int val; | |
402 | ||
403 | val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); | |
404 | if (val < 0) | |
405 | return -EIO; | |
406 | return sprintf(buf, "%#x\n", val); | |
407 | } | |
408 | static DEVICE_ATTR(flags, S_IRUGO, m41t80_sysfs_show_flags, NULL); | |
409 | ||
410 | static ssize_t m41t80_sysfs_show_sqwfreq(struct device *dev, | |
411 | struct device_attribute *attr, char *buf) | |
412 | { | |
413 | struct i2c_client *client = to_i2c_client(dev); | |
414 | int val; | |
415 | ||
416 | val = i2c_smbus_read_byte_data(client, M41T80_REG_SQW); | |
417 | if (val < 0) | |
418 | return -EIO; | |
419 | val = (val >> 4) & 0xf; | |
420 | switch (val) { | |
421 | case 0: | |
422 | break; | |
423 | case 1: | |
424 | val = 32768; | |
425 | break; | |
426 | default: | |
427 | val = 32768 >> val; | |
428 | } | |
429 | return sprintf(buf, "%d\n", val); | |
430 | } | |
431 | static ssize_t m41t80_sysfs_set_sqwfreq(struct device *dev, | |
432 | struct device_attribute *attr, | |
433 | const char *buf, size_t count) | |
434 | { | |
435 | struct i2c_client *client = to_i2c_client(dev); | |
436 | int almon, sqw; | |
437 | int val = simple_strtoul(buf, NULL, 0); | |
438 | ||
439 | if (val) { | |
440 | if (!is_power_of_2(val)) | |
441 | return -EINVAL; | |
442 | val = ilog2(val); | |
443 | if (val == 15) | |
444 | val = 1; | |
445 | else if (val < 14) | |
446 | val = 15 - val; | |
447 | else | |
448 | return -EINVAL; | |
449 | } | |
450 | /* disable SQW, set SQW frequency & re-enable */ | |
451 | almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON); | |
452 | if (almon < 0) | |
453 | return -EIO; | |
454 | sqw = i2c_smbus_read_byte_data(client, M41T80_REG_SQW); | |
455 | if (sqw < 0) | |
456 | return -EIO; | |
457 | sqw = (sqw & 0x0f) | (val << 4); | |
458 | if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, | |
459 | almon & ~M41T80_ALMON_SQWE) < 0 || | |
460 | i2c_smbus_write_byte_data(client, M41T80_REG_SQW, sqw) < 0) | |
461 | return -EIO; | |
462 | if (val && i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, | |
463 | almon | M41T80_ALMON_SQWE) < 0) | |
464 | return -EIO; | |
465 | return count; | |
466 | } | |
467 | static DEVICE_ATTR(sqwfreq, S_IRUGO | S_IWUSR, | |
468 | m41t80_sysfs_show_sqwfreq, m41t80_sysfs_set_sqwfreq); | |
469 | ||
470 | static struct attribute *attrs[] = { | |
471 | &dev_attr_flags.attr, | |
472 | &dev_attr_sqwfreq.attr, | |
473 | NULL, | |
474 | }; | |
475 | static struct attribute_group attr_group = { | |
476 | .attrs = attrs, | |
477 | }; | |
478 | ||
479 | static int m41t80_sysfs_register(struct device *dev) | |
480 | { | |
481 | return sysfs_create_group(&dev->kobj, &attr_group); | |
482 | } | |
483 | #else | |
484 | static int m41t80_sysfs_register(struct device *dev) | |
485 | { | |
486 | return 0; | |
487 | } | |
488 | #endif | |
489 | ||
617780d2 AN |
490 | #ifdef CONFIG_RTC_DRV_M41T80_WDT |
491 | /* | |
492 | ***************************************************************************** | |
493 | * | |
494 | * Watchdog Driver | |
495 | * | |
496 | ***************************************************************************** | |
497 | */ | |
498 | static struct i2c_client *save_client; | |
499 | ||
500 | /* Default margin */ | |
501 | #define WD_TIMO 60 /* 1..31 seconds */ | |
502 | ||
503 | static int wdt_margin = WD_TIMO; | |
504 | module_param(wdt_margin, int, 0); | |
505 | MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)"); | |
506 | ||
507 | static unsigned long wdt_is_open; | |
508 | static int boot_flag; | |
509 | ||
510 | /** | |
511 | * wdt_ping: | |
512 | * | |
513 | * Reload counter one with the watchdog timeout. We don't bother reloading | |
514 | * the cascade counter. | |
515 | */ | |
516 | static void wdt_ping(void) | |
517 | { | |
518 | unsigned char i2c_data[2]; | |
519 | struct i2c_msg msgs1[1] = { | |
520 | { | |
521 | .addr = save_client->addr, | |
522 | .flags = 0, | |
523 | .len = 2, | |
524 | .buf = i2c_data, | |
525 | }, | |
526 | }; | |
527 | i2c_data[0] = 0x09; /* watchdog register */ | |
528 | ||
529 | if (wdt_margin > 31) | |
530 | i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */ | |
531 | else | |
532 | /* | |
533 | * WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02) | |
534 | */ | |
535 | i2c_data[1] = wdt_margin<<2 | 0x82; | |
536 | ||
537 | i2c_transfer(save_client->adapter, msgs1, 1); | |
538 | } | |
539 | ||
540 | /** | |
541 | * wdt_disable: | |
542 | * | |
543 | * disables watchdog. | |
544 | */ | |
545 | static void wdt_disable(void) | |
546 | { | |
547 | unsigned char i2c_data[2], i2c_buf[0x10]; | |
548 | struct i2c_msg msgs0[2] = { | |
549 | { | |
550 | .addr = save_client->addr, | |
551 | .flags = 0, | |
552 | .len = 1, | |
553 | .buf = i2c_data, | |
554 | }, | |
555 | { | |
556 | .addr = save_client->addr, | |
557 | .flags = I2C_M_RD, | |
558 | .len = 1, | |
559 | .buf = i2c_buf, | |
560 | }, | |
561 | }; | |
562 | struct i2c_msg msgs1[1] = { | |
563 | { | |
564 | .addr = save_client->addr, | |
565 | .flags = 0, | |
566 | .len = 2, | |
567 | .buf = i2c_data, | |
568 | }, | |
569 | }; | |
570 | ||
571 | i2c_data[0] = 0x09; | |
572 | i2c_transfer(save_client->adapter, msgs0, 2); | |
573 | ||
574 | i2c_data[0] = 0x09; | |
575 | i2c_data[1] = 0x00; | |
576 | i2c_transfer(save_client->adapter, msgs1, 1); | |
577 | } | |
578 | ||
579 | /** | |
580 | * wdt_write: | |
581 | * @file: file handle to the watchdog | |
582 | * @buf: buffer to write (unused as data does not matter here | |
583 | * @count: count of bytes | |
584 | * @ppos: pointer to the position to write. No seeks allowed | |
585 | * | |
586 | * A write to a watchdog device is defined as a keepalive signal. Any | |
587 | * write of data will do, as we we don't define content meaning. | |
588 | */ | |
589 | static ssize_t wdt_write(struct file *file, const char __user *buf, | |
590 | size_t count, loff_t *ppos) | |
591 | { | |
592 | /* Can't seek (pwrite) on this device | |
593 | if (ppos != &file->f_pos) | |
594 | return -ESPIPE; | |
595 | */ | |
596 | if (count) { | |
597 | wdt_ping(); | |
598 | return 1; | |
599 | } | |
600 | return 0; | |
601 | } | |
602 | ||
603 | static ssize_t wdt_read(struct file *file, char __user *buf, | |
604 | size_t count, loff_t *ppos) | |
605 | { | |
606 | return 0; | |
607 | } | |
608 | ||
609 | /** | |
610 | * wdt_ioctl: | |
611 | * @inode: inode of the device | |
612 | * @file: file handle to the device | |
613 | * @cmd: watchdog command | |
614 | * @arg: argument pointer | |
615 | * | |
616 | * The watchdog API defines a common set of functions for all watchdogs | |
617 | * according to their available features. We only actually usefully support | |
618 | * querying capabilities and current status. | |
619 | */ | |
620 | static int wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | |
621 | unsigned long arg) | |
622 | { | |
623 | int new_margin, rv; | |
624 | static struct watchdog_info ident = { | |
625 | .options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING | | |
626 | WDIOF_SETTIMEOUT, | |
627 | .firmware_version = 1, | |
628 | .identity = "M41T80 WTD" | |
629 | }; | |
630 | ||
631 | switch (cmd) { | |
632 | case WDIOC_GETSUPPORT: | |
633 | return copy_to_user((struct watchdog_info __user *)arg, &ident, | |
634 | sizeof(ident)) ? -EFAULT : 0; | |
635 | ||
636 | case WDIOC_GETSTATUS: | |
637 | case WDIOC_GETBOOTSTATUS: | |
638 | return put_user(boot_flag, (int __user *)arg); | |
639 | case WDIOC_KEEPALIVE: | |
640 | wdt_ping(); | |
641 | return 0; | |
642 | case WDIOC_SETTIMEOUT: | |
643 | if (get_user(new_margin, (int __user *)arg)) | |
644 | return -EFAULT; | |
645 | /* Arbitrary, can't find the card's limits */ | |
646 | if (new_margin < 1 || new_margin > 124) | |
647 | return -EINVAL; | |
648 | wdt_margin = new_margin; | |
649 | wdt_ping(); | |
650 | /* Fall */ | |
651 | case WDIOC_GETTIMEOUT: | |
652 | return put_user(wdt_margin, (int __user *)arg); | |
653 | ||
654 | case WDIOC_SETOPTIONS: | |
655 | if (copy_from_user(&rv, (int __user *)arg, sizeof(int))) | |
656 | return -EFAULT; | |
657 | ||
658 | if (rv & WDIOS_DISABLECARD) { | |
659 | printk(KERN_INFO | |
660 | "rtc-m41t80: disable watchdog\n"); | |
661 | wdt_disable(); | |
662 | } | |
663 | ||
664 | if (rv & WDIOS_ENABLECARD) { | |
665 | printk(KERN_INFO | |
666 | "rtc-m41t80: enable watchdog\n"); | |
667 | wdt_ping(); | |
668 | } | |
669 | ||
670 | return -EINVAL; | |
671 | } | |
672 | return -ENOTTY; | |
673 | } | |
674 | ||
675 | /** | |
676 | * wdt_open: | |
677 | * @inode: inode of device | |
678 | * @file: file handle to device | |
679 | * | |
680 | */ | |
681 | static int wdt_open(struct inode *inode, struct file *file) | |
682 | { | |
683 | if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) { | |
684 | if (test_and_set_bit(0, &wdt_is_open)) | |
685 | return -EBUSY; | |
686 | /* | |
687 | * Activate | |
688 | */ | |
689 | wdt_is_open = 1; | |
690 | return 0; | |
691 | } | |
692 | return -ENODEV; | |
693 | } | |
694 | ||
695 | /** | |
696 | * wdt_close: | |
697 | * @inode: inode to board | |
698 | * @file: file handle to board | |
699 | * | |
700 | */ | |
701 | static int wdt_release(struct inode *inode, struct file *file) | |
702 | { | |
703 | if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) | |
704 | clear_bit(0, &wdt_is_open); | |
705 | return 0; | |
706 | } | |
707 | ||
708 | /** | |
709 | * notify_sys: | |
710 | * @this: our notifier block | |
711 | * @code: the event being reported | |
712 | * @unused: unused | |
713 | * | |
714 | * Our notifier is called on system shutdowns. We want to turn the card | |
715 | * off at reboot otherwise the machine will reboot again during memory | |
716 | * test or worse yet during the following fsck. This would suck, in fact | |
717 | * trust me - if it happens it does suck. | |
718 | */ | |
719 | static int wdt_notify_sys(struct notifier_block *this, unsigned long code, | |
720 | void *unused) | |
721 | { | |
722 | if (code == SYS_DOWN || code == SYS_HALT) | |
723 | /* Disable Watchdog */ | |
724 | wdt_disable(); | |
725 | return NOTIFY_DONE; | |
726 | } | |
727 | ||
728 | static const struct file_operations wdt_fops = { | |
729 | .owner = THIS_MODULE, | |
730 | .read = wdt_read, | |
731 | .ioctl = wdt_ioctl, | |
732 | .write = wdt_write, | |
733 | .open = wdt_open, | |
734 | .release = wdt_release, | |
735 | }; | |
736 | ||
737 | static struct miscdevice wdt_dev = { | |
738 | .minor = WATCHDOG_MINOR, | |
739 | .name = "watchdog", | |
740 | .fops = &wdt_fops, | |
741 | }; | |
742 | ||
743 | /* | |
744 | * The WDT card needs to learn about soft shutdowns in order to | |
745 | * turn the timebomb registers off. | |
746 | */ | |
747 | static struct notifier_block wdt_notifier = { | |
748 | .notifier_call = wdt_notify_sys, | |
749 | }; | |
750 | #endif /* CONFIG_RTC_DRV_M41T80_WDT */ | |
751 | ||
caaff562 AN |
752 | /* |
753 | ***************************************************************************** | |
754 | * | |
755 | * Driver Interface | |
756 | * | |
757 | ***************************************************************************** | |
758 | */ | |
759 | static int m41t80_probe(struct i2c_client *client) | |
760 | { | |
761 | int i, rc = 0; | |
762 | struct rtc_device *rtc = NULL; | |
763 | struct rtc_time tm; | |
764 | const struct m41t80_chip_info *chip; | |
765 | struct m41t80_data *clientdata = NULL; | |
766 | ||
767 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C | |
768 | | I2C_FUNC_SMBUS_BYTE_DATA)) { | |
769 | rc = -ENODEV; | |
770 | goto exit; | |
771 | } | |
772 | ||
773 | dev_info(&client->dev, | |
774 | "chip found, driver version " DRV_VERSION "\n"); | |
775 | ||
776 | chip = NULL; | |
777 | for (i = 0; i < ARRAY_SIZE(m41t80_chip_info_tbl); i++) { | |
778 | if (!strcmp(m41t80_chip_info_tbl[i].name, client->name)) { | |
779 | chip = &m41t80_chip_info_tbl[i]; | |
780 | break; | |
781 | } | |
782 | } | |
783 | if (!chip) { | |
784 | dev_err(&client->dev, "%s is not supported\n", client->name); | |
785 | rc = -ENODEV; | |
786 | goto exit; | |
787 | } | |
788 | ||
789 | clientdata = kzalloc(sizeof(*clientdata), GFP_KERNEL); | |
790 | if (!clientdata) { | |
791 | rc = -ENOMEM; | |
792 | goto exit; | |
793 | } | |
794 | ||
795 | rtc = rtc_device_register(client->name, &client->dev, | |
796 | &m41t80_rtc_ops, THIS_MODULE); | |
797 | if (IS_ERR(rtc)) { | |
798 | rc = PTR_ERR(rtc); | |
799 | rtc = NULL; | |
800 | goto exit; | |
801 | } | |
802 | ||
803 | clientdata->rtc = rtc; | |
804 | clientdata->chip = chip; | |
805 | i2c_set_clientdata(client, clientdata); | |
806 | ||
807 | /* Make sure HT (Halt Update) bit is cleared */ | |
808 | rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR); | |
809 | if (rc < 0) | |
810 | goto ht_err; | |
811 | ||
812 | if (rc & M41T80_ALHOUR_HT) { | |
813 | if (chip->features & M41T80_FEATURE_HT) { | |
814 | m41t80_get_datetime(client, &tm); | |
815 | dev_info(&client->dev, "HT bit was set!\n"); | |
816 | dev_info(&client->dev, | |
817 | "Power Down at " | |
818 | "%04i-%02i-%02i %02i:%02i:%02i\n", | |
819 | tm.tm_year + 1900, | |
820 | tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, | |
821 | tm.tm_min, tm.tm_sec); | |
822 | } | |
823 | if (i2c_smbus_write_byte_data(client, | |
824 | M41T80_REG_ALARM_HOUR, | |
825 | rc & ~M41T80_ALHOUR_HT) < 0) | |
826 | goto ht_err; | |
827 | } | |
828 | ||
829 | /* Make sure ST (stop) bit is cleared */ | |
830 | rc = i2c_smbus_read_byte_data(client, M41T80_REG_SEC); | |
831 | if (rc < 0) | |
832 | goto st_err; | |
833 | ||
834 | if (rc & M41T80_SEC_ST) { | |
835 | if (i2c_smbus_write_byte_data(client, M41T80_REG_SEC, | |
836 | rc & ~M41T80_SEC_ST) < 0) | |
837 | goto st_err; | |
838 | } | |
839 | ||
840 | rc = m41t80_sysfs_register(&client->dev); | |
841 | if (rc) | |
842 | goto exit; | |
843 | ||
617780d2 AN |
844 | #ifdef CONFIG_RTC_DRV_M41T80_WDT |
845 | if (chip->features & M41T80_FEATURE_HT) { | |
846 | rc = misc_register(&wdt_dev); | |
847 | if (rc) | |
848 | goto exit; | |
849 | rc = register_reboot_notifier(&wdt_notifier); | |
850 | if (rc) { | |
851 | misc_deregister(&wdt_dev); | |
852 | goto exit; | |
853 | } | |
854 | save_client = client; | |
855 | } | |
856 | #endif | |
caaff562 AN |
857 | return 0; |
858 | ||
859 | st_err: | |
860 | rc = -EIO; | |
861 | dev_err(&client->dev, "Can't clear ST bit\n"); | |
862 | goto exit; | |
863 | ht_err: | |
864 | rc = -EIO; | |
865 | dev_err(&client->dev, "Can't clear HT bit\n"); | |
866 | goto exit; | |
867 | ||
868 | exit: | |
869 | if (rtc) | |
870 | rtc_device_unregister(rtc); | |
871 | kfree(clientdata); | |
872 | return rc; | |
873 | } | |
874 | ||
875 | static int m41t80_remove(struct i2c_client *client) | |
876 | { | |
877 | struct m41t80_data *clientdata = i2c_get_clientdata(client); | |
878 | struct rtc_device *rtc = clientdata->rtc; | |
879 | ||
617780d2 AN |
880 | #ifdef CONFIG_RTC_DRV_M41T80_WDT |
881 | if (clientdata->chip->features & M41T80_FEATURE_HT) { | |
882 | misc_deregister(&wdt_dev); | |
883 | unregister_reboot_notifier(&wdt_notifier); | |
884 | } | |
885 | #endif | |
caaff562 AN |
886 | if (rtc) |
887 | rtc_device_unregister(rtc); | |
888 | kfree(clientdata); | |
889 | ||
890 | return 0; | |
891 | } | |
892 | ||
893 | static struct i2c_driver m41t80_driver = { | |
894 | .driver = { | |
afe1ab4d | 895 | .name = "rtc-m41t80", |
caaff562 AN |
896 | }, |
897 | .probe = m41t80_probe, | |
898 | .remove = m41t80_remove, | |
899 | }; | |
900 | ||
901 | static int __init m41t80_rtc_init(void) | |
902 | { | |
903 | return i2c_add_driver(&m41t80_driver); | |
904 | } | |
905 | ||
906 | static void __exit m41t80_rtc_exit(void) | |
907 | { | |
908 | i2c_del_driver(&m41t80_driver); | |
909 | } | |
910 | ||
911 | MODULE_AUTHOR("Alexander Bigga <ab@mycable.de>"); | |
912 | MODULE_DESCRIPTION("ST Microelectronics M41T80 series RTC I2C Client Driver"); | |
913 | MODULE_LICENSE("GPL"); | |
914 | MODULE_VERSION(DRV_VERSION); | |
915 | ||
916 | module_init(m41t80_rtc_init); | |
917 | module_exit(m41t80_rtc_exit); |