Commit | Line | Data |
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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 | ||
a737e835 JP |
16 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
17 | ||
35aa64f3 MR |
18 | #include <linux/bcd.h> |
19 | #include <linux/i2c.h> | |
caaff562 | 20 | #include <linux/init.h> |
9fb1f68d | 21 | #include <linux/kernel.h> |
35aa64f3 MR |
22 | #include <linux/module.h> |
23 | #include <linux/rtc.h> | |
caaff562 | 24 | #include <linux/slab.h> |
613655fa | 25 | #include <linux/mutex.h> |
caaff562 | 26 | #include <linux/string.h> |
617780d2 | 27 | #ifdef CONFIG_RTC_DRV_M41T80_WDT |
617780d2 AN |
28 | #include <linux/fs.h> |
29 | #include <linux/ioctl.h> | |
35aa64f3 MR |
30 | #include <linux/miscdevice.h> |
31 | #include <linux/reboot.h> | |
32 | #include <linux/watchdog.h> | |
617780d2 | 33 | #endif |
caaff562 | 34 | |
f2b84ee8 MJ |
35 | #define M41T80_REG_SSEC 0x00 |
36 | #define M41T80_REG_SEC 0x01 | |
37 | #define M41T80_REG_MIN 0x02 | |
38 | #define M41T80_REG_HOUR 0x03 | |
39 | #define M41T80_REG_WDAY 0x04 | |
40 | #define M41T80_REG_DAY 0x05 | |
41 | #define M41T80_REG_MON 0x06 | |
42 | #define M41T80_REG_YEAR 0x07 | |
43 | #define M41T80_REG_ALARM_MON 0x0a | |
44 | #define M41T80_REG_ALARM_DAY 0x0b | |
45 | #define M41T80_REG_ALARM_HOUR 0x0c | |
46 | #define M41T80_REG_ALARM_MIN 0x0d | |
47 | #define M41T80_REG_ALARM_SEC 0x0e | |
48 | #define M41T80_REG_FLAGS 0x0f | |
49 | #define M41T80_REG_SQW 0x13 | |
caaff562 AN |
50 | |
51 | #define M41T80_DATETIME_REG_SIZE (M41T80_REG_YEAR + 1) | |
52 | #define M41T80_ALARM_REG_SIZE \ | |
53 | (M41T80_REG_ALARM_SEC + 1 - M41T80_REG_ALARM_MON) | |
54 | ||
54339f3b MJ |
55 | #define M41T80_SEC_ST BIT(7) /* ST: Stop Bit */ |
56 | #define M41T80_ALMON_AFE BIT(7) /* AFE: AF Enable Bit */ | |
57 | #define M41T80_ALMON_SQWE BIT(6) /* SQWE: SQW Enable Bit */ | |
58 | #define M41T80_ALHOUR_HT BIT(6) /* HT: Halt Update Bit */ | |
59 | #define M41T80_FLAGS_AF BIT(6) /* AF: Alarm Flag Bit */ | |
60 | #define M41T80_FLAGS_BATT_LOW BIT(4) /* BL: Battery Low Bit */ | |
61 | #define M41T80_WATCHDOG_RB2 BIT(7) /* RB: Watchdog resolution */ | |
62 | #define M41T80_WATCHDOG_RB1 BIT(1) /* RB: Watchdog resolution */ | |
63 | #define M41T80_WATCHDOG_RB0 BIT(0) /* RB: Watchdog resolution */ | |
caaff562 | 64 | |
54339f3b MJ |
65 | #define M41T80_FEATURE_HT BIT(0) /* Halt feature */ |
66 | #define M41T80_FEATURE_BL BIT(1) /* Battery low indicator */ | |
67 | #define M41T80_FEATURE_SQ BIT(2) /* Squarewave feature */ | |
68 | #define M41T80_FEATURE_WD BIT(3) /* Extra watchdog resolution */ | |
69 | #define M41T80_FEATURE_SQ_ALT BIT(4) /* RSx bits are in reg 4 */ | |
caaff562 | 70 | |
613655fa | 71 | static DEFINE_MUTEX(m41t80_rtc_mutex); |
3760f736 | 72 | static const struct i2c_device_id m41t80_id[] = { |
f30281f4 | 73 | { "m41t62", M41T80_FEATURE_SQ | M41T80_FEATURE_SQ_ALT }, |
d3a126fc SF |
74 | { "m41t65", M41T80_FEATURE_HT | M41T80_FEATURE_WD }, |
75 | { "m41t80", M41T80_FEATURE_SQ }, | |
76 | { "m41t81", M41T80_FEATURE_HT | M41T80_FEATURE_SQ}, | |
77 | { "m41t81s", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, | |
78 | { "m41t82", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, | |
79 | { "m41t83", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, | |
80 | { "m41st84", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, | |
81 | { "m41st85", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, | |
82 | { "m41st87", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, | |
6b1a5235 | 83 | { "rv4162", M41T80_FEATURE_SQ | M41T80_FEATURE_WD | M41T80_FEATURE_SQ_ALT }, |
3760f736 | 84 | { } |
caaff562 | 85 | }; |
3760f736 | 86 | MODULE_DEVICE_TABLE(i2c, m41t80_id); |
caaff562 AN |
87 | |
88 | struct m41t80_data { | |
3760f736 | 89 | u8 features; |
caaff562 AN |
90 | struct rtc_device *rtc; |
91 | }; | |
92 | ||
93 | static int m41t80_get_datetime(struct i2c_client *client, | |
94 | struct rtc_time *tm) | |
95 | { | |
f2b84ee8 MJ |
96 | unsigned char buf[8]; |
97 | int err; | |
caaff562 | 98 | |
f2b84ee8 MJ |
99 | err = i2c_smbus_read_i2c_block_data(client, M41T80_REG_SSEC, |
100 | sizeof(buf), buf); | |
101 | if (err < 0) { | |
102 | dev_err(&client->dev, "Unable to read date\n"); | |
caaff562 AN |
103 | return -EIO; |
104 | } | |
105 | ||
fe20ba70 AB |
106 | tm->tm_sec = bcd2bin(buf[M41T80_REG_SEC] & 0x7f); |
107 | tm->tm_min = bcd2bin(buf[M41T80_REG_MIN] & 0x7f); | |
108 | tm->tm_hour = bcd2bin(buf[M41T80_REG_HOUR] & 0x3f); | |
109 | tm->tm_mday = bcd2bin(buf[M41T80_REG_DAY] & 0x3f); | |
caaff562 | 110 | tm->tm_wday = buf[M41T80_REG_WDAY] & 0x07; |
fe20ba70 | 111 | tm->tm_mon = bcd2bin(buf[M41T80_REG_MON] & 0x1f) - 1; |
caaff562 AN |
112 | |
113 | /* assume 20YY not 19YY, and ignore the Century Bit */ | |
fe20ba70 | 114 | tm->tm_year = bcd2bin(buf[M41T80_REG_YEAR]) + 100; |
b485fe5e | 115 | return rtc_valid_tm(tm); |
caaff562 AN |
116 | } |
117 | ||
118 | /* Sets the given date and time to the real time clock. */ | |
119 | static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm) | |
120 | { | |
f2b84ee8 MJ |
121 | unsigned char buf[8]; |
122 | int err; | |
caaff562 | 123 | |
f2b84ee8 MJ |
124 | if (tm->tm_year < 100 || tm->tm_year > 199) |
125 | return -EINVAL; | |
caaff562 | 126 | |
caaff562 | 127 | buf[M41T80_REG_SSEC] = 0; |
f2b84ee8 MJ |
128 | buf[M41T80_REG_SEC] = bin2bcd(tm->tm_sec); |
129 | buf[M41T80_REG_MIN] = bin2bcd(tm->tm_min); | |
130 | buf[M41T80_REG_HOUR] = bin2bcd(tm->tm_hour); | |
131 | buf[M41T80_REG_DAY] = bin2bcd(tm->tm_mday); | |
132 | buf[M41T80_REG_MON] = bin2bcd(tm->tm_mon + 1); | |
133 | buf[M41T80_REG_YEAR] = bin2bcd(tm->tm_year - 100); | |
134 | buf[M41T80_REG_WDAY] = tm->tm_wday; | |
135 | ||
136 | err = i2c_smbus_write_i2c_block_data(client, M41T80_REG_SSEC, | |
137 | sizeof(buf), buf); | |
138 | if (err < 0) { | |
139 | dev_err(&client->dev, "Unable to write to date registers\n"); | |
140 | return err; | |
bcebd81d | 141 | } |
caaff562 | 142 | |
f2b84ee8 | 143 | return err; |
caaff562 AN |
144 | } |
145 | ||
caaff562 AN |
146 | static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq) |
147 | { | |
148 | struct i2c_client *client = to_i2c_client(dev); | |
149 | struct m41t80_data *clientdata = i2c_get_clientdata(client); | |
150 | u8 reg; | |
151 | ||
3760f736 | 152 | if (clientdata->features & M41T80_FEATURE_BL) { |
caaff562 AN |
153 | reg = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); |
154 | seq_printf(seq, "battery\t\t: %s\n", | |
155 | (reg & M41T80_FLAGS_BATT_LOW) ? "exhausted" : "ok"); | |
156 | } | |
157 | return 0; | |
158 | } | |
caaff562 AN |
159 | |
160 | static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
161 | { | |
162 | return m41t80_get_datetime(to_i2c_client(dev), tm); | |
163 | } | |
164 | ||
165 | static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
166 | { | |
167 | return m41t80_set_datetime(to_i2c_client(dev), tm); | |
168 | } | |
169 | ||
48e97667 PB |
170 | /* |
171 | * XXX - m41t80 alarm functionality is reported broken. | |
172 | * until it is fixed, don't register alarm functions. | |
173 | */ | |
caaff562 AN |
174 | static struct rtc_class_ops m41t80_rtc_ops = { |
175 | .read_time = m41t80_rtc_read_time, | |
176 | .set_time = m41t80_rtc_set_time, | |
caaff562 | 177 | .proc = m41t80_rtc_proc, |
caaff562 AN |
178 | }; |
179 | ||
ef6b3125 MJ |
180 | static ssize_t flags_show(struct device *dev, |
181 | struct device_attribute *attr, char *buf) | |
caaff562 AN |
182 | { |
183 | struct i2c_client *client = to_i2c_client(dev); | |
184 | int val; | |
185 | ||
186 | val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); | |
187 | if (val < 0) | |
85d77047 | 188 | return val; |
caaff562 AN |
189 | return sprintf(buf, "%#x\n", val); |
190 | } | |
ef6b3125 | 191 | static DEVICE_ATTR_RO(flags); |
caaff562 | 192 | |
ef6b3125 MJ |
193 | static ssize_t sqwfreq_show(struct device *dev, |
194 | struct device_attribute *attr, char *buf) | |
caaff562 AN |
195 | { |
196 | struct i2c_client *client = to_i2c_client(dev); | |
d3a126fc | 197 | struct m41t80_data *clientdata = i2c_get_clientdata(client); |
f30281f4 | 198 | int val, reg_sqw; |
caaff562 | 199 | |
d3a126fc SF |
200 | if (!(clientdata->features & M41T80_FEATURE_SQ)) |
201 | return -EINVAL; | |
202 | ||
f30281f4 DG |
203 | reg_sqw = M41T80_REG_SQW; |
204 | if (clientdata->features & M41T80_FEATURE_SQ_ALT) | |
205 | reg_sqw = M41T80_REG_WDAY; | |
206 | val = i2c_smbus_read_byte_data(client, reg_sqw); | |
caaff562 | 207 | if (val < 0) |
85d77047 | 208 | return val; |
caaff562 AN |
209 | val = (val >> 4) & 0xf; |
210 | switch (val) { | |
211 | case 0: | |
212 | break; | |
213 | case 1: | |
214 | val = 32768; | |
215 | break; | |
216 | default: | |
217 | val = 32768 >> val; | |
218 | } | |
219 | return sprintf(buf, "%d\n", val); | |
220 | } | |
ef6b3125 MJ |
221 | |
222 | static ssize_t sqwfreq_store(struct device *dev, | |
223 | struct device_attribute *attr, | |
224 | const char *buf, size_t count) | |
caaff562 AN |
225 | { |
226 | struct i2c_client *client = to_i2c_client(dev); | |
d3a126fc | 227 | struct m41t80_data *clientdata = i2c_get_clientdata(client); |
85d77047 | 228 | int almon, sqw, reg_sqw, rc; |
fc99b901 MJ |
229 | unsigned long val; |
230 | ||
231 | rc = kstrtoul(buf, 0, &val); | |
232 | if (rc < 0) | |
233 | return rc; | |
caaff562 | 234 | |
d3a126fc SF |
235 | if (!(clientdata->features & M41T80_FEATURE_SQ)) |
236 | return -EINVAL; | |
237 | ||
caaff562 AN |
238 | if (val) { |
239 | if (!is_power_of_2(val)) | |
240 | return -EINVAL; | |
241 | val = ilog2(val); | |
242 | if (val == 15) | |
243 | val = 1; | |
244 | else if (val < 14) | |
245 | val = 15 - val; | |
246 | else | |
247 | return -EINVAL; | |
248 | } | |
249 | /* disable SQW, set SQW frequency & re-enable */ | |
250 | almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON); | |
251 | if (almon < 0) | |
85d77047 | 252 | return almon; |
f30281f4 DG |
253 | reg_sqw = M41T80_REG_SQW; |
254 | if (clientdata->features & M41T80_FEATURE_SQ_ALT) | |
255 | reg_sqw = M41T80_REG_WDAY; | |
256 | sqw = i2c_smbus_read_byte_data(client, reg_sqw); | |
caaff562 | 257 | if (sqw < 0) |
85d77047 | 258 | return sqw; |
caaff562 | 259 | sqw = (sqw & 0x0f) | (val << 4); |
85d77047 WS |
260 | |
261 | rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, | |
fc99b901 | 262 | almon & ~M41T80_ALMON_SQWE); |
85d77047 WS |
263 | if (rc < 0) |
264 | return rc; | |
265 | ||
266 | if (val) { | |
267 | rc = i2c_smbus_write_byte_data(client, reg_sqw, sqw); | |
268 | if (rc < 0) | |
269 | return rc; | |
270 | ||
271 | rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, | |
fc99b901 MJ |
272 | almon | M41T80_ALMON_SQWE); |
273 | if (rc < 0) | |
85d77047 WS |
274 | return rc; |
275 | } | |
caaff562 AN |
276 | return count; |
277 | } | |
ef6b3125 | 278 | static DEVICE_ATTR_RW(sqwfreq); |
caaff562 AN |
279 | |
280 | static struct attribute *attrs[] = { | |
281 | &dev_attr_flags.attr, | |
282 | &dev_attr_sqwfreq.attr, | |
283 | NULL, | |
284 | }; | |
fc99b901 | 285 | |
caaff562 AN |
286 | static struct attribute_group attr_group = { |
287 | .attrs = attrs, | |
288 | }; | |
289 | ||
617780d2 AN |
290 | #ifdef CONFIG_RTC_DRV_M41T80_WDT |
291 | /* | |
292 | ***************************************************************************** | |
293 | * | |
294 | * Watchdog Driver | |
295 | * | |
296 | ***************************************************************************** | |
297 | */ | |
298 | static struct i2c_client *save_client; | |
299 | ||
300 | /* Default margin */ | |
301 | #define WD_TIMO 60 /* 1..31 seconds */ | |
302 | ||
303 | static int wdt_margin = WD_TIMO; | |
304 | module_param(wdt_margin, int, 0); | |
305 | MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)"); | |
306 | ||
307 | static unsigned long wdt_is_open; | |
308 | static int boot_flag; | |
309 | ||
310 | /** | |
311 | * wdt_ping: | |
312 | * | |
313 | * Reload counter one with the watchdog timeout. We don't bother reloading | |
314 | * the cascade counter. | |
315 | */ | |
316 | static void wdt_ping(void) | |
317 | { | |
318 | unsigned char i2c_data[2]; | |
319 | struct i2c_msg msgs1[1] = { | |
320 | { | |
321 | .addr = save_client->addr, | |
322 | .flags = 0, | |
323 | .len = 2, | |
324 | .buf = i2c_data, | |
325 | }, | |
326 | }; | |
d3a126fc SF |
327 | struct m41t80_data *clientdata = i2c_get_clientdata(save_client); |
328 | ||
617780d2 AN |
329 | i2c_data[0] = 0x09; /* watchdog register */ |
330 | ||
331 | if (wdt_margin > 31) | |
332 | i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */ | |
333 | else | |
334 | /* | |
335 | * WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02) | |
336 | */ | |
fc99b901 | 337 | i2c_data[1] = wdt_margin << 2 | 0x82; |
617780d2 | 338 | |
d3a126fc SF |
339 | /* |
340 | * M41T65 has three bits for watchdog resolution. Don't set bit 7, as | |
341 | * that would be an invalid resolution. | |
342 | */ | |
343 | if (clientdata->features & M41T80_FEATURE_WD) | |
344 | i2c_data[1] &= ~M41T80_WATCHDOG_RB2; | |
345 | ||
617780d2 AN |
346 | i2c_transfer(save_client->adapter, msgs1, 1); |
347 | } | |
348 | ||
349 | /** | |
350 | * wdt_disable: | |
351 | * | |
352 | * disables watchdog. | |
353 | */ | |
354 | static void wdt_disable(void) | |
355 | { | |
356 | unsigned char i2c_data[2], i2c_buf[0x10]; | |
357 | struct i2c_msg msgs0[2] = { | |
358 | { | |
359 | .addr = save_client->addr, | |
360 | .flags = 0, | |
361 | .len = 1, | |
362 | .buf = i2c_data, | |
363 | }, | |
364 | { | |
365 | .addr = save_client->addr, | |
366 | .flags = I2C_M_RD, | |
367 | .len = 1, | |
368 | .buf = i2c_buf, | |
369 | }, | |
370 | }; | |
371 | struct i2c_msg msgs1[1] = { | |
372 | { | |
373 | .addr = save_client->addr, | |
374 | .flags = 0, | |
375 | .len = 2, | |
376 | .buf = i2c_data, | |
377 | }, | |
378 | }; | |
379 | ||
380 | i2c_data[0] = 0x09; | |
381 | i2c_transfer(save_client->adapter, msgs0, 2); | |
382 | ||
383 | i2c_data[0] = 0x09; | |
384 | i2c_data[1] = 0x00; | |
385 | i2c_transfer(save_client->adapter, msgs1, 1); | |
386 | } | |
387 | ||
388 | /** | |
389 | * wdt_write: | |
390 | * @file: file handle to the watchdog | |
391 | * @buf: buffer to write (unused as data does not matter here | |
392 | * @count: count of bytes | |
393 | * @ppos: pointer to the position to write. No seeks allowed | |
394 | * | |
395 | * A write to a watchdog device is defined as a keepalive signal. Any | |
396 | * write of data will do, as we we don't define content meaning. | |
397 | */ | |
398 | static ssize_t wdt_write(struct file *file, const char __user *buf, | |
399 | size_t count, loff_t *ppos) | |
400 | { | |
617780d2 AN |
401 | if (count) { |
402 | wdt_ping(); | |
403 | return 1; | |
404 | } | |
405 | return 0; | |
406 | } | |
407 | ||
408 | static ssize_t wdt_read(struct file *file, char __user *buf, | |
409 | size_t count, loff_t *ppos) | |
410 | { | |
411 | return 0; | |
412 | } | |
413 | ||
414 | /** | |
415 | * wdt_ioctl: | |
416 | * @inode: inode of the device | |
417 | * @file: file handle to the device | |
418 | * @cmd: watchdog command | |
419 | * @arg: argument pointer | |
420 | * | |
421 | * The watchdog API defines a common set of functions for all watchdogs | |
422 | * according to their available features. We only actually usefully support | |
423 | * querying capabilities and current status. | |
424 | */ | |
55929332 | 425 | static int wdt_ioctl(struct file *file, unsigned int cmd, |
617780d2 AN |
426 | unsigned long arg) |
427 | { | |
428 | int new_margin, rv; | |
429 | static struct watchdog_info ident = { | |
430 | .options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING | | |
431 | WDIOF_SETTIMEOUT, | |
432 | .firmware_version = 1, | |
433 | .identity = "M41T80 WTD" | |
434 | }; | |
435 | ||
436 | switch (cmd) { | |
437 | case WDIOC_GETSUPPORT: | |
438 | return copy_to_user((struct watchdog_info __user *)arg, &ident, | |
439 | sizeof(ident)) ? -EFAULT : 0; | |
440 | ||
441 | case WDIOC_GETSTATUS: | |
442 | case WDIOC_GETBOOTSTATUS: | |
443 | return put_user(boot_flag, (int __user *)arg); | |
444 | case WDIOC_KEEPALIVE: | |
445 | wdt_ping(); | |
446 | return 0; | |
447 | case WDIOC_SETTIMEOUT: | |
448 | if (get_user(new_margin, (int __user *)arg)) | |
449 | return -EFAULT; | |
450 | /* Arbitrary, can't find the card's limits */ | |
451 | if (new_margin < 1 || new_margin > 124) | |
452 | return -EINVAL; | |
453 | wdt_margin = new_margin; | |
454 | wdt_ping(); | |
455 | /* Fall */ | |
456 | case WDIOC_GETTIMEOUT: | |
457 | return put_user(wdt_margin, (int __user *)arg); | |
458 | ||
459 | case WDIOC_SETOPTIONS: | |
460 | if (copy_from_user(&rv, (int __user *)arg, sizeof(int))) | |
461 | return -EFAULT; | |
462 | ||
463 | if (rv & WDIOS_DISABLECARD) { | |
a737e835 | 464 | pr_info("disable watchdog\n"); |
617780d2 AN |
465 | wdt_disable(); |
466 | } | |
467 | ||
468 | if (rv & WDIOS_ENABLECARD) { | |
a737e835 | 469 | pr_info("enable watchdog\n"); |
617780d2 AN |
470 | wdt_ping(); |
471 | } | |
472 | ||
473 | return -EINVAL; | |
474 | } | |
475 | return -ENOTTY; | |
476 | } | |
477 | ||
55929332 AB |
478 | static long wdt_unlocked_ioctl(struct file *file, unsigned int cmd, |
479 | unsigned long arg) | |
480 | { | |
481 | int ret; | |
482 | ||
613655fa | 483 | mutex_lock(&m41t80_rtc_mutex); |
55929332 | 484 | ret = wdt_ioctl(file, cmd, arg); |
613655fa | 485 | mutex_unlock(&m41t80_rtc_mutex); |
55929332 AB |
486 | |
487 | return ret; | |
488 | } | |
489 | ||
617780d2 AN |
490 | /** |
491 | * wdt_open: | |
492 | * @inode: inode of device | |
493 | * @file: file handle to device | |
494 | * | |
495 | */ | |
496 | static int wdt_open(struct inode *inode, struct file *file) | |
497 | { | |
498 | if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) { | |
613655fa | 499 | mutex_lock(&m41t80_rtc_mutex); |
41012735 | 500 | if (test_and_set_bit(0, &wdt_is_open)) { |
613655fa | 501 | mutex_unlock(&m41t80_rtc_mutex); |
617780d2 | 502 | return -EBUSY; |
41012735 | 503 | } |
617780d2 AN |
504 | /* |
505 | * Activate | |
506 | */ | |
507 | wdt_is_open = 1; | |
613655fa | 508 | mutex_unlock(&m41t80_rtc_mutex); |
09eeb1f5 | 509 | return nonseekable_open(inode, file); |
617780d2 AN |
510 | } |
511 | return -ENODEV; | |
512 | } | |
513 | ||
514 | /** | |
515 | * wdt_close: | |
516 | * @inode: inode to board | |
517 | * @file: file handle to board | |
518 | * | |
519 | */ | |
520 | static int wdt_release(struct inode *inode, struct file *file) | |
521 | { | |
522 | if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) | |
523 | clear_bit(0, &wdt_is_open); | |
524 | return 0; | |
525 | } | |
526 | ||
527 | /** | |
528 | * notify_sys: | |
529 | * @this: our notifier block | |
530 | * @code: the event being reported | |
531 | * @unused: unused | |
532 | * | |
533 | * Our notifier is called on system shutdowns. We want to turn the card | |
534 | * off at reboot otherwise the machine will reboot again during memory | |
535 | * test or worse yet during the following fsck. This would suck, in fact | |
536 | * trust me - if it happens it does suck. | |
537 | */ | |
538 | static int wdt_notify_sys(struct notifier_block *this, unsigned long code, | |
539 | void *unused) | |
540 | { | |
541 | if (code == SYS_DOWN || code == SYS_HALT) | |
542 | /* Disable Watchdog */ | |
543 | wdt_disable(); | |
544 | return NOTIFY_DONE; | |
545 | } | |
546 | ||
547 | static const struct file_operations wdt_fops = { | |
548 | .owner = THIS_MODULE, | |
549 | .read = wdt_read, | |
55929332 | 550 | .unlocked_ioctl = wdt_unlocked_ioctl, |
617780d2 AN |
551 | .write = wdt_write, |
552 | .open = wdt_open, | |
553 | .release = wdt_release, | |
6038f373 | 554 | .llseek = no_llseek, |
617780d2 AN |
555 | }; |
556 | ||
557 | static struct miscdevice wdt_dev = { | |
558 | .minor = WATCHDOG_MINOR, | |
559 | .name = "watchdog", | |
560 | .fops = &wdt_fops, | |
561 | }; | |
562 | ||
563 | /* | |
564 | * The WDT card needs to learn about soft shutdowns in order to | |
565 | * turn the timebomb registers off. | |
566 | */ | |
567 | static struct notifier_block wdt_notifier = { | |
568 | .notifier_call = wdt_notify_sys, | |
569 | }; | |
570 | #endif /* CONFIG_RTC_DRV_M41T80_WDT */ | |
571 | ||
caaff562 AN |
572 | /* |
573 | ***************************************************************************** | |
574 | * | |
575 | * Driver Interface | |
576 | * | |
577 | ***************************************************************************** | |
578 | */ | |
ef6b3125 MJ |
579 | |
580 | static void m41t80_remove_sysfs_group(void *_dev) | |
581 | { | |
582 | struct device *dev = _dev; | |
583 | ||
584 | sysfs_remove_group(&dev->kobj, &attr_group); | |
585 | } | |
586 | ||
d2653e92 JD |
587 | static int m41t80_probe(struct i2c_client *client, |
588 | const struct i2c_device_id *id) | |
caaff562 | 589 | { |
f2b84ee8 | 590 | struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); |
3760f736 | 591 | int rc = 0; |
caaff562 AN |
592 | struct rtc_device *rtc = NULL; |
593 | struct rtc_time tm; | |
caaff562 AN |
594 | struct m41t80_data *clientdata = NULL; |
595 | ||
f2b84ee8 MJ |
596 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK | |
597 | I2C_FUNC_SMBUS_BYTE_DATA)) { | |
598 | dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK\n"); | |
c67fedfa | 599 | return -ENODEV; |
f2b84ee8 | 600 | } |
caaff562 | 601 | |
4ebabb78 | 602 | clientdata = devm_kzalloc(&client->dev, sizeof(*clientdata), |
fc99b901 | 603 | GFP_KERNEL); |
c67fedfa WS |
604 | if (!clientdata) |
605 | return -ENOMEM; | |
caaff562 | 606 | |
a015dbc1 JS |
607 | clientdata->features = id->driver_data; |
608 | i2c_set_clientdata(client, clientdata); | |
609 | ||
4ebabb78 | 610 | rtc = devm_rtc_device_register(&client->dev, client->name, |
fc99b901 | 611 | &m41t80_rtc_ops, THIS_MODULE); |
c67fedfa WS |
612 | if (IS_ERR(rtc)) |
613 | return PTR_ERR(rtc); | |
caaff562 AN |
614 | |
615 | clientdata->rtc = rtc; | |
caaff562 AN |
616 | |
617 | /* Make sure HT (Halt Update) bit is cleared */ | |
618 | rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR); | |
caaff562 | 619 | |
c67fedfa | 620 | if (rc >= 0 && rc & M41T80_ALHOUR_HT) { |
3760f736 | 621 | if (clientdata->features & M41T80_FEATURE_HT) { |
caaff562 AN |
622 | m41t80_get_datetime(client, &tm); |
623 | dev_info(&client->dev, "HT bit was set!\n"); | |
624 | dev_info(&client->dev, | |
fc99b901 | 625 | "Power Down at %04i-%02i-%02i %02i:%02i:%02i\n", |
caaff562 AN |
626 | tm.tm_year + 1900, |
627 | tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, | |
628 | tm.tm_min, tm.tm_sec); | |
629 | } | |
c67fedfa | 630 | rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_HOUR, |
fc99b901 | 631 | rc & ~M41T80_ALHOUR_HT); |
c67fedfa WS |
632 | } |
633 | ||
634 | if (rc < 0) { | |
635 | dev_err(&client->dev, "Can't clear HT bit\n"); | |
85d77047 | 636 | return rc; |
caaff562 AN |
637 | } |
638 | ||
639 | /* Make sure ST (stop) bit is cleared */ | |
640 | rc = i2c_smbus_read_byte_data(client, M41T80_REG_SEC); | |
caaff562 | 641 | |
c67fedfa WS |
642 | if (rc >= 0 && rc & M41T80_SEC_ST) |
643 | rc = i2c_smbus_write_byte_data(client, M41T80_REG_SEC, | |
fc99b901 | 644 | rc & ~M41T80_SEC_ST); |
c67fedfa WS |
645 | if (rc < 0) { |
646 | dev_err(&client->dev, "Can't clear ST bit\n"); | |
85d77047 | 647 | return rc; |
caaff562 AN |
648 | } |
649 | ||
ef6b3125 MJ |
650 | /* Export sysfs entries */ |
651 | rc = sysfs_create_group(&(&client->dev)->kobj, &attr_group); | |
652 | if (rc) { | |
653 | dev_err(&client->dev, "Failed to create sysfs group: %d\n", rc); | |
c67fedfa | 654 | return rc; |
ef6b3125 MJ |
655 | } |
656 | ||
657 | rc = devm_add_action(&client->dev, m41t80_remove_sysfs_group, | |
658 | &client->dev); | |
659 | if (rc) { | |
660 | m41t80_remove_sysfs_group(&client->dev); | |
661 | dev_err(&client->dev, | |
662 | "Failed to add sysfs cleanup action: %d\n", rc); | |
663 | return rc; | |
664 | } | |
caaff562 | 665 | |
617780d2 | 666 | #ifdef CONFIG_RTC_DRV_M41T80_WDT |
3760f736 | 667 | if (clientdata->features & M41T80_FEATURE_HT) { |
417607d0 | 668 | save_client = client; |
617780d2 AN |
669 | rc = misc_register(&wdt_dev); |
670 | if (rc) | |
c67fedfa | 671 | return rc; |
617780d2 AN |
672 | rc = register_reboot_notifier(&wdt_notifier); |
673 | if (rc) { | |
674 | misc_deregister(&wdt_dev); | |
c67fedfa | 675 | return rc; |
617780d2 | 676 | } |
617780d2 AN |
677 | } |
678 | #endif | |
caaff562 | 679 | return 0; |
caaff562 AN |
680 | } |
681 | ||
682 | static int m41t80_remove(struct i2c_client *client) | |
683 | { | |
4ebabb78 | 684 | #ifdef CONFIG_RTC_DRV_M41T80_WDT |
caaff562 | 685 | struct m41t80_data *clientdata = i2c_get_clientdata(client); |
caaff562 | 686 | |
3760f736 | 687 | if (clientdata->features & M41T80_FEATURE_HT) { |
617780d2 AN |
688 | misc_deregister(&wdt_dev); |
689 | unregister_reboot_notifier(&wdt_notifier); | |
690 | } | |
691 | #endif | |
caaff562 AN |
692 | |
693 | return 0; | |
694 | } | |
695 | ||
696 | static struct i2c_driver m41t80_driver = { | |
697 | .driver = { | |
afe1ab4d | 698 | .name = "rtc-m41t80", |
caaff562 AN |
699 | }, |
700 | .probe = m41t80_probe, | |
701 | .remove = m41t80_remove, | |
3760f736 | 702 | .id_table = m41t80_id, |
caaff562 AN |
703 | }; |
704 | ||
0abc9201 | 705 | module_i2c_driver(m41t80_driver); |
caaff562 AN |
706 | |
707 | MODULE_AUTHOR("Alexander Bigga <ab@mycable.de>"); | |
708 | MODULE_DESCRIPTION("ST Microelectronics M41T80 series RTC I2C Client Driver"); | |
709 | MODULE_LICENSE("GPL"); |