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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 | ||
3760f736 JD |
63 | static const struct i2c_device_id m41t80_id[] = { |
64 | { "m41t80", 0 }, | |
65 | { "m41t81", M41T80_FEATURE_HT }, | |
66 | { "m41t81s", M41T80_FEATURE_HT | M41T80_FEATURE_BL }, | |
67 | { "m41t82", M41T80_FEATURE_HT | M41T80_FEATURE_BL }, | |
68 | { "m41t83", M41T80_FEATURE_HT | M41T80_FEATURE_BL }, | |
69 | { "m41st84", M41T80_FEATURE_HT | M41T80_FEATURE_BL }, | |
70 | { "m41st85", M41T80_FEATURE_HT | M41T80_FEATURE_BL }, | |
71 | { "m41st87", M41T80_FEATURE_HT | M41T80_FEATURE_BL }, | |
72 | { } | |
caaff562 | 73 | }; |
3760f736 | 74 | MODULE_DEVICE_TABLE(i2c, m41t80_id); |
caaff562 AN |
75 | |
76 | struct m41t80_data { | |
3760f736 | 77 | u8 features; |
caaff562 AN |
78 | struct rtc_device *rtc; |
79 | }; | |
80 | ||
81 | static int m41t80_get_datetime(struct i2c_client *client, | |
82 | struct rtc_time *tm) | |
83 | { | |
84 | u8 buf[M41T80_DATETIME_REG_SIZE], dt_addr[1] = { M41T80_REG_SEC }; | |
85 | struct i2c_msg msgs[] = { | |
86 | { | |
87 | .addr = client->addr, | |
88 | .flags = 0, | |
89 | .len = 1, | |
90 | .buf = dt_addr, | |
91 | }, | |
92 | { | |
93 | .addr = client->addr, | |
94 | .flags = I2C_M_RD, | |
95 | .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC, | |
96 | .buf = buf + M41T80_REG_SEC, | |
97 | }, | |
98 | }; | |
99 | ||
100 | if (i2c_transfer(client->adapter, msgs, 2) < 0) { | |
101 | dev_err(&client->dev, "read error\n"); | |
102 | return -EIO; | |
103 | } | |
104 | ||
105 | tm->tm_sec = BCD2BIN(buf[M41T80_REG_SEC] & 0x7f); | |
106 | tm->tm_min = BCD2BIN(buf[M41T80_REG_MIN] & 0x7f); | |
107 | tm->tm_hour = BCD2BIN(buf[M41T80_REG_HOUR] & 0x3f); | |
108 | tm->tm_mday = BCD2BIN(buf[M41T80_REG_DAY] & 0x3f); | |
109 | tm->tm_wday = buf[M41T80_REG_WDAY] & 0x07; | |
110 | tm->tm_mon = BCD2BIN(buf[M41T80_REG_MON] & 0x1f) - 1; | |
111 | ||
112 | /* assume 20YY not 19YY, and ignore the Century Bit */ | |
113 | tm->tm_year = BCD2BIN(buf[M41T80_REG_YEAR]) + 100; | |
114 | return 0; | |
115 | } | |
116 | ||
117 | /* Sets the given date and time to the real time clock. */ | |
118 | static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm) | |
119 | { | |
120 | u8 wbuf[1 + M41T80_DATETIME_REG_SIZE]; | |
121 | u8 *buf = &wbuf[1]; | |
122 | u8 dt_addr[1] = { M41T80_REG_SEC }; | |
123 | struct i2c_msg msgs_in[] = { | |
124 | { | |
125 | .addr = client->addr, | |
126 | .flags = 0, | |
127 | .len = 1, | |
128 | .buf = dt_addr, | |
129 | }, | |
130 | { | |
131 | .addr = client->addr, | |
132 | .flags = I2C_M_RD, | |
133 | .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC, | |
134 | .buf = buf + M41T80_REG_SEC, | |
135 | }, | |
136 | }; | |
137 | struct i2c_msg msgs[] = { | |
138 | { | |
139 | .addr = client->addr, | |
140 | .flags = 0, | |
141 | .len = 1 + M41T80_DATETIME_REG_SIZE, | |
142 | .buf = wbuf, | |
143 | }, | |
144 | }; | |
145 | ||
146 | /* Read current reg values into buf[1..7] */ | |
147 | if (i2c_transfer(client->adapter, msgs_in, 2) < 0) { | |
148 | dev_err(&client->dev, "read error\n"); | |
149 | return -EIO; | |
150 | } | |
151 | ||
152 | wbuf[0] = 0; /* offset into rtc's regs */ | |
153 | /* Merge time-data and register flags into buf[0..7] */ | |
154 | buf[M41T80_REG_SSEC] = 0; | |
155 | buf[M41T80_REG_SEC] = | |
156 | BIN2BCD(tm->tm_sec) | (buf[M41T80_REG_SEC] & ~0x7f); | |
157 | buf[M41T80_REG_MIN] = | |
158 | BIN2BCD(tm->tm_min) | (buf[M41T80_REG_MIN] & ~0x7f); | |
159 | buf[M41T80_REG_HOUR] = | |
160 | BIN2BCD(tm->tm_hour) | (buf[M41T80_REG_HOUR] & ~0x3f) ; | |
161 | buf[M41T80_REG_WDAY] = | |
162 | (tm->tm_wday & 0x07) | (buf[M41T80_REG_WDAY] & ~0x07); | |
163 | buf[M41T80_REG_DAY] = | |
164 | BIN2BCD(tm->tm_mday) | (buf[M41T80_REG_DAY] & ~0x3f); | |
165 | buf[M41T80_REG_MON] = | |
166 | BIN2BCD(tm->tm_mon + 1) | (buf[M41T80_REG_MON] & ~0x1f); | |
167 | /* assume 20YY not 19YY */ | |
168 | buf[M41T80_REG_YEAR] = BIN2BCD(tm->tm_year % 100); | |
169 | ||
170 | if (i2c_transfer(client->adapter, msgs, 1) != 1) { | |
171 | dev_err(&client->dev, "write error\n"); | |
172 | return -EIO; | |
173 | } | |
174 | return 0; | |
175 | } | |
176 | ||
177 | #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE) | |
178 | static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq) | |
179 | { | |
180 | struct i2c_client *client = to_i2c_client(dev); | |
181 | struct m41t80_data *clientdata = i2c_get_clientdata(client); | |
182 | u8 reg; | |
183 | ||
3760f736 | 184 | if (clientdata->features & M41T80_FEATURE_BL) { |
caaff562 AN |
185 | reg = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); |
186 | seq_printf(seq, "battery\t\t: %s\n", | |
187 | (reg & M41T80_FLAGS_BATT_LOW) ? "exhausted" : "ok"); | |
188 | } | |
189 | return 0; | |
190 | } | |
191 | #else | |
192 | #define m41t80_rtc_proc NULL | |
193 | #endif | |
194 | ||
195 | static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
196 | { | |
197 | return m41t80_get_datetime(to_i2c_client(dev), tm); | |
198 | } | |
199 | ||
200 | static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
201 | { | |
202 | return m41t80_set_datetime(to_i2c_client(dev), tm); | |
203 | } | |
204 | ||
205 | #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE) | |
206 | static int | |
207 | m41t80_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) | |
208 | { | |
209 | struct i2c_client *client = to_i2c_client(dev); | |
210 | int rc; | |
211 | ||
212 | switch (cmd) { | |
213 | case RTC_AIE_OFF: | |
214 | case RTC_AIE_ON: | |
215 | break; | |
216 | default: | |
217 | return -ENOIOCTLCMD; | |
218 | } | |
219 | ||
220 | rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON); | |
221 | if (rc < 0) | |
222 | goto err; | |
223 | switch (cmd) { | |
224 | case RTC_AIE_OFF: | |
225 | rc &= ~M41T80_ALMON_AFE; | |
226 | break; | |
227 | case RTC_AIE_ON: | |
228 | rc |= M41T80_ALMON_AFE; | |
229 | break; | |
230 | } | |
231 | if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, rc) < 0) | |
232 | goto err; | |
233 | return 0; | |
234 | err: | |
235 | return -EIO; | |
236 | } | |
237 | #else | |
238 | #define m41t80_rtc_ioctl NULL | |
239 | #endif | |
240 | ||
241 | static int m41t80_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *t) | |
242 | { | |
243 | struct i2c_client *client = to_i2c_client(dev); | |
244 | u8 wbuf[1 + M41T80_ALARM_REG_SIZE]; | |
245 | u8 *buf = &wbuf[1]; | |
246 | u8 *reg = buf - M41T80_REG_ALARM_MON; | |
247 | u8 dt_addr[1] = { M41T80_REG_ALARM_MON }; | |
248 | struct i2c_msg msgs_in[] = { | |
249 | { | |
250 | .addr = client->addr, | |
251 | .flags = 0, | |
252 | .len = 1, | |
253 | .buf = dt_addr, | |
254 | }, | |
255 | { | |
256 | .addr = client->addr, | |
257 | .flags = I2C_M_RD, | |
258 | .len = M41T80_ALARM_REG_SIZE, | |
259 | .buf = buf, | |
260 | }, | |
261 | }; | |
262 | struct i2c_msg msgs[] = { | |
263 | { | |
264 | .addr = client->addr, | |
265 | .flags = 0, | |
266 | .len = 1 + M41T80_ALARM_REG_SIZE, | |
267 | .buf = wbuf, | |
268 | }, | |
269 | }; | |
270 | ||
271 | if (i2c_transfer(client->adapter, msgs_in, 2) < 0) { | |
272 | dev_err(&client->dev, "read error\n"); | |
273 | return -EIO; | |
274 | } | |
275 | reg[M41T80_REG_ALARM_MON] &= ~(0x1f | M41T80_ALMON_AFE); | |
276 | reg[M41T80_REG_ALARM_DAY] = 0; | |
277 | reg[M41T80_REG_ALARM_HOUR] &= ~(0x3f | 0x80); | |
278 | reg[M41T80_REG_ALARM_MIN] = 0; | |
279 | reg[M41T80_REG_ALARM_SEC] = 0; | |
280 | ||
281 | wbuf[0] = M41T80_REG_ALARM_MON; /* offset into rtc's regs */ | |
282 | reg[M41T80_REG_ALARM_SEC] |= t->time.tm_sec >= 0 ? | |
283 | BIN2BCD(t->time.tm_sec) : 0x80; | |
284 | reg[M41T80_REG_ALARM_MIN] |= t->time.tm_min >= 0 ? | |
285 | BIN2BCD(t->time.tm_min) : 0x80; | |
286 | reg[M41T80_REG_ALARM_HOUR] |= t->time.tm_hour >= 0 ? | |
287 | BIN2BCD(t->time.tm_hour) : 0x80; | |
288 | reg[M41T80_REG_ALARM_DAY] |= t->time.tm_mday >= 0 ? | |
289 | BIN2BCD(t->time.tm_mday) : 0x80; | |
290 | if (t->time.tm_mon >= 0) | |
291 | reg[M41T80_REG_ALARM_MON] |= BIN2BCD(t->time.tm_mon + 1); | |
292 | else | |
293 | reg[M41T80_REG_ALARM_DAY] |= 0x40; | |
294 | ||
295 | if (i2c_transfer(client->adapter, msgs, 1) != 1) { | |
296 | dev_err(&client->dev, "write error\n"); | |
297 | return -EIO; | |
298 | } | |
299 | ||
300 | if (t->enabled) { | |
301 | reg[M41T80_REG_ALARM_MON] |= M41T80_ALMON_AFE; | |
302 | if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, | |
303 | reg[M41T80_REG_ALARM_MON]) < 0) { | |
304 | dev_err(&client->dev, "write error\n"); | |
305 | return -EIO; | |
306 | } | |
307 | } | |
308 | return 0; | |
309 | } | |
310 | ||
311 | static int m41t80_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *t) | |
312 | { | |
313 | struct i2c_client *client = to_i2c_client(dev); | |
314 | u8 buf[M41T80_ALARM_REG_SIZE + 1]; /* all alarm regs and flags */ | |
315 | u8 dt_addr[1] = { M41T80_REG_ALARM_MON }; | |
316 | u8 *reg = buf - M41T80_REG_ALARM_MON; | |
317 | struct i2c_msg msgs[] = { | |
318 | { | |
319 | .addr = client->addr, | |
320 | .flags = 0, | |
321 | .len = 1, | |
322 | .buf = dt_addr, | |
323 | }, | |
324 | { | |
325 | .addr = client->addr, | |
326 | .flags = I2C_M_RD, | |
327 | .len = M41T80_ALARM_REG_SIZE + 1, | |
328 | .buf = buf, | |
329 | }, | |
330 | }; | |
331 | ||
332 | if (i2c_transfer(client->adapter, msgs, 2) < 0) { | |
333 | dev_err(&client->dev, "read error\n"); | |
334 | return -EIO; | |
335 | } | |
336 | t->time.tm_sec = -1; | |
337 | t->time.tm_min = -1; | |
338 | t->time.tm_hour = -1; | |
339 | t->time.tm_mday = -1; | |
340 | t->time.tm_mon = -1; | |
341 | if (!(reg[M41T80_REG_ALARM_SEC] & 0x80)) | |
342 | t->time.tm_sec = BCD2BIN(reg[M41T80_REG_ALARM_SEC] & 0x7f); | |
343 | if (!(reg[M41T80_REG_ALARM_MIN] & 0x80)) | |
344 | t->time.tm_min = BCD2BIN(reg[M41T80_REG_ALARM_MIN] & 0x7f); | |
345 | if (!(reg[M41T80_REG_ALARM_HOUR] & 0x80)) | |
346 | t->time.tm_hour = BCD2BIN(reg[M41T80_REG_ALARM_HOUR] & 0x3f); | |
347 | if (!(reg[M41T80_REG_ALARM_DAY] & 0x80)) | |
348 | t->time.tm_mday = BCD2BIN(reg[M41T80_REG_ALARM_DAY] & 0x3f); | |
349 | if (!(reg[M41T80_REG_ALARM_DAY] & 0x40)) | |
350 | t->time.tm_mon = BCD2BIN(reg[M41T80_REG_ALARM_MON] & 0x1f) - 1; | |
351 | t->time.tm_year = -1; | |
352 | t->time.tm_wday = -1; | |
353 | t->time.tm_yday = -1; | |
354 | t->time.tm_isdst = -1; | |
355 | t->enabled = !!(reg[M41T80_REG_ALARM_MON] & M41T80_ALMON_AFE); | |
356 | t->pending = !!(reg[M41T80_REG_FLAGS] & M41T80_FLAGS_AF); | |
357 | return 0; | |
358 | } | |
359 | ||
360 | static struct rtc_class_ops m41t80_rtc_ops = { | |
361 | .read_time = m41t80_rtc_read_time, | |
362 | .set_time = m41t80_rtc_set_time, | |
363 | .read_alarm = m41t80_rtc_read_alarm, | |
364 | .set_alarm = m41t80_rtc_set_alarm, | |
365 | .proc = m41t80_rtc_proc, | |
366 | .ioctl = m41t80_rtc_ioctl, | |
367 | }; | |
368 | ||
369 | #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE) | |
370 | static ssize_t m41t80_sysfs_show_flags(struct device *dev, | |
371 | struct device_attribute *attr, char *buf) | |
372 | { | |
373 | struct i2c_client *client = to_i2c_client(dev); | |
374 | int val; | |
375 | ||
376 | val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); | |
377 | if (val < 0) | |
378 | return -EIO; | |
379 | return sprintf(buf, "%#x\n", val); | |
380 | } | |
381 | static DEVICE_ATTR(flags, S_IRUGO, m41t80_sysfs_show_flags, NULL); | |
382 | ||
383 | static ssize_t m41t80_sysfs_show_sqwfreq(struct device *dev, | |
384 | struct device_attribute *attr, char *buf) | |
385 | { | |
386 | struct i2c_client *client = to_i2c_client(dev); | |
387 | int val; | |
388 | ||
389 | val = i2c_smbus_read_byte_data(client, M41T80_REG_SQW); | |
390 | if (val < 0) | |
391 | return -EIO; | |
392 | val = (val >> 4) & 0xf; | |
393 | switch (val) { | |
394 | case 0: | |
395 | break; | |
396 | case 1: | |
397 | val = 32768; | |
398 | break; | |
399 | default: | |
400 | val = 32768 >> val; | |
401 | } | |
402 | return sprintf(buf, "%d\n", val); | |
403 | } | |
404 | static ssize_t m41t80_sysfs_set_sqwfreq(struct device *dev, | |
405 | struct device_attribute *attr, | |
406 | const char *buf, size_t count) | |
407 | { | |
408 | struct i2c_client *client = to_i2c_client(dev); | |
409 | int almon, sqw; | |
410 | int val = simple_strtoul(buf, NULL, 0); | |
411 | ||
412 | if (val) { | |
413 | if (!is_power_of_2(val)) | |
414 | return -EINVAL; | |
415 | val = ilog2(val); | |
416 | if (val == 15) | |
417 | val = 1; | |
418 | else if (val < 14) | |
419 | val = 15 - val; | |
420 | else | |
421 | return -EINVAL; | |
422 | } | |
423 | /* disable SQW, set SQW frequency & re-enable */ | |
424 | almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON); | |
425 | if (almon < 0) | |
426 | return -EIO; | |
427 | sqw = i2c_smbus_read_byte_data(client, M41T80_REG_SQW); | |
428 | if (sqw < 0) | |
429 | return -EIO; | |
430 | sqw = (sqw & 0x0f) | (val << 4); | |
431 | if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, | |
432 | almon & ~M41T80_ALMON_SQWE) < 0 || | |
433 | i2c_smbus_write_byte_data(client, M41T80_REG_SQW, sqw) < 0) | |
434 | return -EIO; | |
435 | if (val && i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, | |
436 | almon | M41T80_ALMON_SQWE) < 0) | |
437 | return -EIO; | |
438 | return count; | |
439 | } | |
440 | static DEVICE_ATTR(sqwfreq, S_IRUGO | S_IWUSR, | |
441 | m41t80_sysfs_show_sqwfreq, m41t80_sysfs_set_sqwfreq); | |
442 | ||
443 | static struct attribute *attrs[] = { | |
444 | &dev_attr_flags.attr, | |
445 | &dev_attr_sqwfreq.attr, | |
446 | NULL, | |
447 | }; | |
448 | static struct attribute_group attr_group = { | |
449 | .attrs = attrs, | |
450 | }; | |
451 | ||
452 | static int m41t80_sysfs_register(struct device *dev) | |
453 | { | |
454 | return sysfs_create_group(&dev->kobj, &attr_group); | |
455 | } | |
456 | #else | |
457 | static int m41t80_sysfs_register(struct device *dev) | |
458 | { | |
459 | return 0; | |
460 | } | |
461 | #endif | |
462 | ||
617780d2 AN |
463 | #ifdef CONFIG_RTC_DRV_M41T80_WDT |
464 | /* | |
465 | ***************************************************************************** | |
466 | * | |
467 | * Watchdog Driver | |
468 | * | |
469 | ***************************************************************************** | |
470 | */ | |
471 | static struct i2c_client *save_client; | |
472 | ||
473 | /* Default margin */ | |
474 | #define WD_TIMO 60 /* 1..31 seconds */ | |
475 | ||
476 | static int wdt_margin = WD_TIMO; | |
477 | module_param(wdt_margin, int, 0); | |
478 | MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)"); | |
479 | ||
480 | static unsigned long wdt_is_open; | |
481 | static int boot_flag; | |
482 | ||
483 | /** | |
484 | * wdt_ping: | |
485 | * | |
486 | * Reload counter one with the watchdog timeout. We don't bother reloading | |
487 | * the cascade counter. | |
488 | */ | |
489 | static void wdt_ping(void) | |
490 | { | |
491 | unsigned char i2c_data[2]; | |
492 | struct i2c_msg msgs1[1] = { | |
493 | { | |
494 | .addr = save_client->addr, | |
495 | .flags = 0, | |
496 | .len = 2, | |
497 | .buf = i2c_data, | |
498 | }, | |
499 | }; | |
500 | i2c_data[0] = 0x09; /* watchdog register */ | |
501 | ||
502 | if (wdt_margin > 31) | |
503 | i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */ | |
504 | else | |
505 | /* | |
506 | * WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02) | |
507 | */ | |
508 | i2c_data[1] = wdt_margin<<2 | 0x82; | |
509 | ||
510 | i2c_transfer(save_client->adapter, msgs1, 1); | |
511 | } | |
512 | ||
513 | /** | |
514 | * wdt_disable: | |
515 | * | |
516 | * disables watchdog. | |
517 | */ | |
518 | static void wdt_disable(void) | |
519 | { | |
520 | unsigned char i2c_data[2], i2c_buf[0x10]; | |
521 | struct i2c_msg msgs0[2] = { | |
522 | { | |
523 | .addr = save_client->addr, | |
524 | .flags = 0, | |
525 | .len = 1, | |
526 | .buf = i2c_data, | |
527 | }, | |
528 | { | |
529 | .addr = save_client->addr, | |
530 | .flags = I2C_M_RD, | |
531 | .len = 1, | |
532 | .buf = i2c_buf, | |
533 | }, | |
534 | }; | |
535 | struct i2c_msg msgs1[1] = { | |
536 | { | |
537 | .addr = save_client->addr, | |
538 | .flags = 0, | |
539 | .len = 2, | |
540 | .buf = i2c_data, | |
541 | }, | |
542 | }; | |
543 | ||
544 | i2c_data[0] = 0x09; | |
545 | i2c_transfer(save_client->adapter, msgs0, 2); | |
546 | ||
547 | i2c_data[0] = 0x09; | |
548 | i2c_data[1] = 0x00; | |
549 | i2c_transfer(save_client->adapter, msgs1, 1); | |
550 | } | |
551 | ||
552 | /** | |
553 | * wdt_write: | |
554 | * @file: file handle to the watchdog | |
555 | * @buf: buffer to write (unused as data does not matter here | |
556 | * @count: count of bytes | |
557 | * @ppos: pointer to the position to write. No seeks allowed | |
558 | * | |
559 | * A write to a watchdog device is defined as a keepalive signal. Any | |
560 | * write of data will do, as we we don't define content meaning. | |
561 | */ | |
562 | static ssize_t wdt_write(struct file *file, const char __user *buf, | |
563 | size_t count, loff_t *ppos) | |
564 | { | |
565 | /* Can't seek (pwrite) on this device | |
566 | if (ppos != &file->f_pos) | |
567 | return -ESPIPE; | |
568 | */ | |
569 | if (count) { | |
570 | wdt_ping(); | |
571 | return 1; | |
572 | } | |
573 | return 0; | |
574 | } | |
575 | ||
576 | static ssize_t wdt_read(struct file *file, char __user *buf, | |
577 | size_t count, loff_t *ppos) | |
578 | { | |
579 | return 0; | |
580 | } | |
581 | ||
582 | /** | |
583 | * wdt_ioctl: | |
584 | * @inode: inode of the device | |
585 | * @file: file handle to the device | |
586 | * @cmd: watchdog command | |
587 | * @arg: argument pointer | |
588 | * | |
589 | * The watchdog API defines a common set of functions for all watchdogs | |
590 | * according to their available features. We only actually usefully support | |
591 | * querying capabilities and current status. | |
592 | */ | |
593 | static int wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | |
594 | unsigned long arg) | |
595 | { | |
596 | int new_margin, rv; | |
597 | static struct watchdog_info ident = { | |
598 | .options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING | | |
599 | WDIOF_SETTIMEOUT, | |
600 | .firmware_version = 1, | |
601 | .identity = "M41T80 WTD" | |
602 | }; | |
603 | ||
604 | switch (cmd) { | |
605 | case WDIOC_GETSUPPORT: | |
606 | return copy_to_user((struct watchdog_info __user *)arg, &ident, | |
607 | sizeof(ident)) ? -EFAULT : 0; | |
608 | ||
609 | case WDIOC_GETSTATUS: | |
610 | case WDIOC_GETBOOTSTATUS: | |
611 | return put_user(boot_flag, (int __user *)arg); | |
612 | case WDIOC_KEEPALIVE: | |
613 | wdt_ping(); | |
614 | return 0; | |
615 | case WDIOC_SETTIMEOUT: | |
616 | if (get_user(new_margin, (int __user *)arg)) | |
617 | return -EFAULT; | |
618 | /* Arbitrary, can't find the card's limits */ | |
619 | if (new_margin < 1 || new_margin > 124) | |
620 | return -EINVAL; | |
621 | wdt_margin = new_margin; | |
622 | wdt_ping(); | |
623 | /* Fall */ | |
624 | case WDIOC_GETTIMEOUT: | |
625 | return put_user(wdt_margin, (int __user *)arg); | |
626 | ||
627 | case WDIOC_SETOPTIONS: | |
628 | if (copy_from_user(&rv, (int __user *)arg, sizeof(int))) | |
629 | return -EFAULT; | |
630 | ||
631 | if (rv & WDIOS_DISABLECARD) { | |
632 | printk(KERN_INFO | |
633 | "rtc-m41t80: disable watchdog\n"); | |
634 | wdt_disable(); | |
635 | } | |
636 | ||
637 | if (rv & WDIOS_ENABLECARD) { | |
638 | printk(KERN_INFO | |
639 | "rtc-m41t80: enable watchdog\n"); | |
640 | wdt_ping(); | |
641 | } | |
642 | ||
643 | return -EINVAL; | |
644 | } | |
645 | return -ENOTTY; | |
646 | } | |
647 | ||
648 | /** | |
649 | * wdt_open: | |
650 | * @inode: inode of device | |
651 | * @file: file handle to device | |
652 | * | |
653 | */ | |
654 | static int wdt_open(struct inode *inode, struct file *file) | |
655 | { | |
656 | if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) { | |
657 | if (test_and_set_bit(0, &wdt_is_open)) | |
658 | return -EBUSY; | |
659 | /* | |
660 | * Activate | |
661 | */ | |
662 | wdt_is_open = 1; | |
663 | return 0; | |
664 | } | |
665 | return -ENODEV; | |
666 | } | |
667 | ||
668 | /** | |
669 | * wdt_close: | |
670 | * @inode: inode to board | |
671 | * @file: file handle to board | |
672 | * | |
673 | */ | |
674 | static int wdt_release(struct inode *inode, struct file *file) | |
675 | { | |
676 | if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) | |
677 | clear_bit(0, &wdt_is_open); | |
678 | return 0; | |
679 | } | |
680 | ||
681 | /** | |
682 | * notify_sys: | |
683 | * @this: our notifier block | |
684 | * @code: the event being reported | |
685 | * @unused: unused | |
686 | * | |
687 | * Our notifier is called on system shutdowns. We want to turn the card | |
688 | * off at reboot otherwise the machine will reboot again during memory | |
689 | * test or worse yet during the following fsck. This would suck, in fact | |
690 | * trust me - if it happens it does suck. | |
691 | */ | |
692 | static int wdt_notify_sys(struct notifier_block *this, unsigned long code, | |
693 | void *unused) | |
694 | { | |
695 | if (code == SYS_DOWN || code == SYS_HALT) | |
696 | /* Disable Watchdog */ | |
697 | wdt_disable(); | |
698 | return NOTIFY_DONE; | |
699 | } | |
700 | ||
701 | static const struct file_operations wdt_fops = { | |
702 | .owner = THIS_MODULE, | |
703 | .read = wdt_read, | |
704 | .ioctl = wdt_ioctl, | |
705 | .write = wdt_write, | |
706 | .open = wdt_open, | |
707 | .release = wdt_release, | |
708 | }; | |
709 | ||
710 | static struct miscdevice wdt_dev = { | |
711 | .minor = WATCHDOG_MINOR, | |
712 | .name = "watchdog", | |
713 | .fops = &wdt_fops, | |
714 | }; | |
715 | ||
716 | /* | |
717 | * The WDT card needs to learn about soft shutdowns in order to | |
718 | * turn the timebomb registers off. | |
719 | */ | |
720 | static struct notifier_block wdt_notifier = { | |
721 | .notifier_call = wdt_notify_sys, | |
722 | }; | |
723 | #endif /* CONFIG_RTC_DRV_M41T80_WDT */ | |
724 | ||
caaff562 AN |
725 | /* |
726 | ***************************************************************************** | |
727 | * | |
728 | * Driver Interface | |
729 | * | |
730 | ***************************************************************************** | |
731 | */ | |
d2653e92 JD |
732 | static int m41t80_probe(struct i2c_client *client, |
733 | const struct i2c_device_id *id) | |
caaff562 | 734 | { |
3760f736 | 735 | int rc = 0; |
caaff562 AN |
736 | struct rtc_device *rtc = NULL; |
737 | struct rtc_time tm; | |
caaff562 AN |
738 | struct m41t80_data *clientdata = NULL; |
739 | ||
740 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C | |
741 | | I2C_FUNC_SMBUS_BYTE_DATA)) { | |
742 | rc = -ENODEV; | |
743 | goto exit; | |
744 | } | |
745 | ||
746 | dev_info(&client->dev, | |
747 | "chip found, driver version " DRV_VERSION "\n"); | |
748 | ||
caaff562 AN |
749 | clientdata = kzalloc(sizeof(*clientdata), GFP_KERNEL); |
750 | if (!clientdata) { | |
751 | rc = -ENOMEM; | |
752 | goto exit; | |
753 | } | |
754 | ||
755 | rtc = rtc_device_register(client->name, &client->dev, | |
756 | &m41t80_rtc_ops, THIS_MODULE); | |
757 | if (IS_ERR(rtc)) { | |
758 | rc = PTR_ERR(rtc); | |
759 | rtc = NULL; | |
760 | goto exit; | |
761 | } | |
762 | ||
763 | clientdata->rtc = rtc; | |
3760f736 | 764 | clientdata->features = id->driver_data; |
caaff562 AN |
765 | i2c_set_clientdata(client, clientdata); |
766 | ||
767 | /* Make sure HT (Halt Update) bit is cleared */ | |
768 | rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR); | |
769 | if (rc < 0) | |
770 | goto ht_err; | |
771 | ||
772 | if (rc & M41T80_ALHOUR_HT) { | |
3760f736 | 773 | if (clientdata->features & M41T80_FEATURE_HT) { |
caaff562 AN |
774 | m41t80_get_datetime(client, &tm); |
775 | dev_info(&client->dev, "HT bit was set!\n"); | |
776 | dev_info(&client->dev, | |
777 | "Power Down at " | |
778 | "%04i-%02i-%02i %02i:%02i:%02i\n", | |
779 | tm.tm_year + 1900, | |
780 | tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, | |
781 | tm.tm_min, tm.tm_sec); | |
782 | } | |
783 | if (i2c_smbus_write_byte_data(client, | |
784 | M41T80_REG_ALARM_HOUR, | |
785 | rc & ~M41T80_ALHOUR_HT) < 0) | |
786 | goto ht_err; | |
787 | } | |
788 | ||
789 | /* Make sure ST (stop) bit is cleared */ | |
790 | rc = i2c_smbus_read_byte_data(client, M41T80_REG_SEC); | |
791 | if (rc < 0) | |
792 | goto st_err; | |
793 | ||
794 | if (rc & M41T80_SEC_ST) { | |
795 | if (i2c_smbus_write_byte_data(client, M41T80_REG_SEC, | |
796 | rc & ~M41T80_SEC_ST) < 0) | |
797 | goto st_err; | |
798 | } | |
799 | ||
800 | rc = m41t80_sysfs_register(&client->dev); | |
801 | if (rc) | |
802 | goto exit; | |
803 | ||
617780d2 | 804 | #ifdef CONFIG_RTC_DRV_M41T80_WDT |
3760f736 | 805 | if (clientdata->features & M41T80_FEATURE_HT) { |
617780d2 AN |
806 | rc = misc_register(&wdt_dev); |
807 | if (rc) | |
808 | goto exit; | |
809 | rc = register_reboot_notifier(&wdt_notifier); | |
810 | if (rc) { | |
811 | misc_deregister(&wdt_dev); | |
812 | goto exit; | |
813 | } | |
814 | save_client = client; | |
815 | } | |
816 | #endif | |
caaff562 AN |
817 | return 0; |
818 | ||
819 | st_err: | |
820 | rc = -EIO; | |
821 | dev_err(&client->dev, "Can't clear ST bit\n"); | |
822 | goto exit; | |
823 | ht_err: | |
824 | rc = -EIO; | |
825 | dev_err(&client->dev, "Can't clear HT bit\n"); | |
826 | goto exit; | |
827 | ||
828 | exit: | |
829 | if (rtc) | |
830 | rtc_device_unregister(rtc); | |
831 | kfree(clientdata); | |
832 | return rc; | |
833 | } | |
834 | ||
835 | static int m41t80_remove(struct i2c_client *client) | |
836 | { | |
837 | struct m41t80_data *clientdata = i2c_get_clientdata(client); | |
838 | struct rtc_device *rtc = clientdata->rtc; | |
839 | ||
617780d2 | 840 | #ifdef CONFIG_RTC_DRV_M41T80_WDT |
3760f736 | 841 | if (clientdata->features & M41T80_FEATURE_HT) { |
617780d2 AN |
842 | misc_deregister(&wdt_dev); |
843 | unregister_reboot_notifier(&wdt_notifier); | |
844 | } | |
845 | #endif | |
caaff562 AN |
846 | if (rtc) |
847 | rtc_device_unregister(rtc); | |
848 | kfree(clientdata); | |
849 | ||
850 | return 0; | |
851 | } | |
852 | ||
853 | static struct i2c_driver m41t80_driver = { | |
854 | .driver = { | |
afe1ab4d | 855 | .name = "rtc-m41t80", |
caaff562 AN |
856 | }, |
857 | .probe = m41t80_probe, | |
858 | .remove = m41t80_remove, | |
3760f736 | 859 | .id_table = m41t80_id, |
caaff562 AN |
860 | }; |
861 | ||
862 | static int __init m41t80_rtc_init(void) | |
863 | { | |
864 | return i2c_add_driver(&m41t80_driver); | |
865 | } | |
866 | ||
867 | static void __exit m41t80_rtc_exit(void) | |
868 | { | |
869 | i2c_del_driver(&m41t80_driver); | |
870 | } | |
871 | ||
872 | MODULE_AUTHOR("Alexander Bigga <ab@mycable.de>"); | |
873 | MODULE_DESCRIPTION("ST Microelectronics M41T80 series RTC I2C Client Driver"); | |
874 | MODULE_LICENSE("GPL"); | |
875 | MODULE_VERSION(DRV_VERSION); | |
876 | ||
877 | module_init(m41t80_rtc_init); | |
878 | module_exit(m41t80_rtc_exit); |