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b5a82d62 AZ |
1 | /* |
2 | * An I2C driver for the Philips PCF8563 RTC | |
3 | * Copyright 2005-06 Tower Technologies | |
4 | * | |
5 | * Author: Alessandro Zummo <a.zummo@towertech.it> | |
6 | * Maintainers: http://www.nslu2-linux.org/ | |
7 | * | |
8 | * based on the other drivers in this same directory. | |
9 | * | |
10 | * http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or modify | |
13 | * it under the terms of the GNU General Public License version 2 as | |
14 | * published by the Free Software Foundation. | |
15 | */ | |
16 | ||
17 | #include <linux/i2c.h> | |
18 | #include <linux/bcd.h> | |
19 | #include <linux/rtc.h> | |
20 | ||
21 | #define DRV_VERSION "0.4.2" | |
22 | ||
23 | /* Addresses to scan: none | |
24 | * This chip cannot be reliably autodetected. An empty eeprom | |
25 | * located at 0x51 will pass the validation routine due to | |
26 | * the way the registers are implemented. | |
27 | */ | |
28 | static unsigned short normal_i2c[] = { I2C_CLIENT_END }; | |
29 | ||
30 | /* Module parameters */ | |
31 | I2C_CLIENT_INSMOD; | |
32 | ||
33 | #define PCF8563_REG_ST1 0x00 /* status */ | |
34 | #define PCF8563_REG_ST2 0x01 | |
35 | ||
36 | #define PCF8563_REG_SC 0x02 /* datetime */ | |
37 | #define PCF8563_REG_MN 0x03 | |
38 | #define PCF8563_REG_HR 0x04 | |
39 | #define PCF8563_REG_DM 0x05 | |
40 | #define PCF8563_REG_DW 0x06 | |
41 | #define PCF8563_REG_MO 0x07 | |
42 | #define PCF8563_REG_YR 0x08 | |
43 | ||
44 | #define PCF8563_REG_AMN 0x09 /* alarm */ | |
45 | #define PCF8563_REG_AHR 0x0A | |
46 | #define PCF8563_REG_ADM 0x0B | |
47 | #define PCF8563_REG_ADW 0x0C | |
48 | ||
49 | #define PCF8563_REG_CLKO 0x0D /* clock out */ | |
50 | #define PCF8563_REG_TMRC 0x0E /* timer control */ | |
51 | #define PCF8563_REG_TMR 0x0F /* timer */ | |
52 | ||
53 | #define PCF8563_SC_LV 0x80 /* low voltage */ | |
54 | #define PCF8563_MO_C 0x80 /* century */ | |
55 | ||
cbb94502 AN |
56 | struct pcf8563 { |
57 | struct i2c_client client; | |
58 | /* | |
59 | * The meaning of MO_C bit varies by the chip type. | |
60 | * From PCF8563 datasheet: this bit is toggled when the years | |
61 | * register overflows from 99 to 00 | |
62 | * 0 indicates the century is 20xx | |
63 | * 1 indicates the century is 19xx | |
64 | * From RTC8564 datasheet: this bit indicates change of | |
65 | * century. When the year digit data overflows from 99 to 00, | |
66 | * this bit is set. By presetting it to 0 while still in the | |
67 | * 20th century, it will be set in year 2000, ... | |
68 | * There seems no reliable way to know how the system use this | |
69 | * bit. So let's do it heuristically, assuming we are live in | |
70 | * 1970...2069. | |
71 | */ | |
72 | int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */ | |
73 | }; | |
74 | ||
b5a82d62 AZ |
75 | static int pcf8563_probe(struct i2c_adapter *adapter, int address, int kind); |
76 | static int pcf8563_detach(struct i2c_client *client); | |
77 | ||
78 | /* | |
79 | * In the routines that deal directly with the pcf8563 hardware, we use | |
80 | * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. | |
81 | */ | |
82 | static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm) | |
83 | { | |
cbb94502 | 84 | struct pcf8563 *pcf8563 = container_of(client, struct pcf8563, client); |
b5a82d62 AZ |
85 | unsigned char buf[13] = { PCF8563_REG_ST1 }; |
86 | ||
87 | struct i2c_msg msgs[] = { | |
88 | { client->addr, 0, 1, buf }, /* setup read ptr */ | |
89 | { client->addr, I2C_M_RD, 13, buf }, /* read status + date */ | |
90 | }; | |
91 | ||
92 | /* read registers */ | |
93 | if ((i2c_transfer(client->adapter, msgs, 2)) != 2) { | |
94 | dev_err(&client->dev, "%s: read error\n", __FUNCTION__); | |
95 | return -EIO; | |
96 | } | |
97 | ||
98 | if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) | |
99 | dev_info(&client->dev, | |
100 | "low voltage detected, date/time is not reliable.\n"); | |
101 | ||
102 | dev_dbg(&client->dev, | |
103 | "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, " | |
104 | "mday=%02x, wday=%02x, mon=%02x, year=%02x\n", | |
105 | __FUNCTION__, | |
106 | buf[0], buf[1], buf[2], buf[3], | |
107 | buf[4], buf[5], buf[6], buf[7], | |
108 | buf[8]); | |
109 | ||
110 | ||
111 | tm->tm_sec = BCD2BIN(buf[PCF8563_REG_SC] & 0x7F); | |
112 | tm->tm_min = BCD2BIN(buf[PCF8563_REG_MN] & 0x7F); | |
113 | tm->tm_hour = BCD2BIN(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */ | |
114 | tm->tm_mday = BCD2BIN(buf[PCF8563_REG_DM] & 0x3F); | |
115 | tm->tm_wday = buf[PCF8563_REG_DW] & 0x07; | |
116 | tm->tm_mon = BCD2BIN(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */ | |
cbb94502 AN |
117 | tm->tm_year = BCD2BIN(buf[PCF8563_REG_YR]); |
118 | if (tm->tm_year < 70) | |
119 | tm->tm_year += 100; /* assume we are in 1970...2069 */ | |
120 | /* detect the polarity heuristically. see note above. */ | |
121 | pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ? | |
122 | (tm->tm_year >= 100) : (tm->tm_year < 100); | |
b5a82d62 AZ |
123 | |
124 | dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " | |
125 | "mday=%d, mon=%d, year=%d, wday=%d\n", | |
126 | __FUNCTION__, | |
127 | tm->tm_sec, tm->tm_min, tm->tm_hour, | |
128 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); | |
129 | ||
130 | /* the clock can give out invalid datetime, but we cannot return | |
131 | * -EINVAL otherwise hwclock will refuse to set the time on bootup. | |
132 | */ | |
133 | if (rtc_valid_tm(tm) < 0) | |
134 | dev_err(&client->dev, "retrieved date/time is not valid.\n"); | |
135 | ||
136 | return 0; | |
137 | } | |
138 | ||
139 | static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm) | |
140 | { | |
cbb94502 | 141 | struct pcf8563 *pcf8563 = container_of(client, struct pcf8563, client); |
b5a82d62 AZ |
142 | int i, err; |
143 | unsigned char buf[9]; | |
144 | ||
145 | dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, " | |
146 | "mday=%d, mon=%d, year=%d, wday=%d\n", | |
147 | __FUNCTION__, | |
148 | tm->tm_sec, tm->tm_min, tm->tm_hour, | |
149 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); | |
150 | ||
151 | /* hours, minutes and seconds */ | |
152 | buf[PCF8563_REG_SC] = BIN2BCD(tm->tm_sec); | |
153 | buf[PCF8563_REG_MN] = BIN2BCD(tm->tm_min); | |
154 | buf[PCF8563_REG_HR] = BIN2BCD(tm->tm_hour); | |
155 | ||
156 | buf[PCF8563_REG_DM] = BIN2BCD(tm->tm_mday); | |
157 | ||
158 | /* month, 1 - 12 */ | |
159 | buf[PCF8563_REG_MO] = BIN2BCD(tm->tm_mon + 1); | |
160 | ||
161 | /* year and century */ | |
162 | buf[PCF8563_REG_YR] = BIN2BCD(tm->tm_year % 100); | |
cbb94502 | 163 | if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100)) |
b5a82d62 AZ |
164 | buf[PCF8563_REG_MO] |= PCF8563_MO_C; |
165 | ||
166 | buf[PCF8563_REG_DW] = tm->tm_wday & 0x07; | |
167 | ||
168 | /* write register's data */ | |
169 | for (i = 0; i < 7; i++) { | |
170 | unsigned char data[2] = { PCF8563_REG_SC + i, | |
171 | buf[PCF8563_REG_SC + i] }; | |
172 | ||
173 | err = i2c_master_send(client, data, sizeof(data)); | |
174 | if (err != sizeof(data)) { | |
175 | dev_err(&client->dev, | |
176 | "%s: err=%d addr=%02x, data=%02x\n", | |
177 | __FUNCTION__, err, data[0], data[1]); | |
178 | return -EIO; | |
179 | } | |
180 | }; | |
181 | ||
182 | return 0; | |
183 | } | |
184 | ||
185 | struct pcf8563_limit | |
186 | { | |
187 | unsigned char reg; | |
188 | unsigned char mask; | |
189 | unsigned char min; | |
190 | unsigned char max; | |
191 | }; | |
192 | ||
193 | static int pcf8563_validate_client(struct i2c_client *client) | |
194 | { | |
195 | int i; | |
196 | ||
197 | static const struct pcf8563_limit pattern[] = { | |
198 | /* register, mask, min, max */ | |
199 | { PCF8563_REG_SC, 0x7F, 0, 59 }, | |
200 | { PCF8563_REG_MN, 0x7F, 0, 59 }, | |
201 | { PCF8563_REG_HR, 0x3F, 0, 23 }, | |
202 | { PCF8563_REG_DM, 0x3F, 0, 31 }, | |
203 | { PCF8563_REG_MO, 0x1F, 0, 12 }, | |
204 | }; | |
205 | ||
206 | /* check limits (only registers with bcd values) */ | |
207 | for (i = 0; i < ARRAY_SIZE(pattern); i++) { | |
208 | int xfer; | |
209 | unsigned char value; | |
210 | unsigned char buf = pattern[i].reg; | |
211 | ||
212 | struct i2c_msg msgs[] = { | |
213 | { client->addr, 0, 1, &buf }, | |
214 | { client->addr, I2C_M_RD, 1, &buf }, | |
215 | }; | |
216 | ||
217 | xfer = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); | |
218 | ||
219 | if (xfer != ARRAY_SIZE(msgs)) { | |
a14e1893 | 220 | dev_err(&client->dev, |
b5a82d62 AZ |
221 | "%s: could not read register 0x%02X\n", |
222 | __FUNCTION__, pattern[i].reg); | |
223 | ||
224 | return -EIO; | |
225 | } | |
226 | ||
227 | value = BCD2BIN(buf & pattern[i].mask); | |
228 | ||
229 | if (value > pattern[i].max || | |
230 | value < pattern[i].min) { | |
a14e1893 | 231 | dev_dbg(&client->dev, |
b5a82d62 AZ |
232 | "%s: pattern=%d, reg=%x, mask=0x%02x, min=%d, " |
233 | "max=%d, value=%d, raw=0x%02X\n", | |
234 | __FUNCTION__, i, pattern[i].reg, pattern[i].mask, | |
235 | pattern[i].min, pattern[i].max, | |
236 | value, buf); | |
237 | ||
238 | return -ENODEV; | |
239 | } | |
240 | } | |
241 | ||
242 | return 0; | |
243 | } | |
244 | ||
245 | static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
246 | { | |
247 | return pcf8563_get_datetime(to_i2c_client(dev), tm); | |
248 | } | |
249 | ||
250 | static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
251 | { | |
252 | return pcf8563_set_datetime(to_i2c_client(dev), tm); | |
253 | } | |
254 | ||
ff8371ac | 255 | static const struct rtc_class_ops pcf8563_rtc_ops = { |
b5a82d62 AZ |
256 | .read_time = pcf8563_rtc_read_time, |
257 | .set_time = pcf8563_rtc_set_time, | |
258 | }; | |
259 | ||
260 | static int pcf8563_attach(struct i2c_adapter *adapter) | |
261 | { | |
262 | return i2c_probe(adapter, &addr_data, pcf8563_probe); | |
263 | } | |
264 | ||
265 | static struct i2c_driver pcf8563_driver = { | |
266 | .driver = { | |
267 | .name = "pcf8563", | |
268 | }, | |
269 | .id = I2C_DRIVERID_PCF8563, | |
270 | .attach_adapter = &pcf8563_attach, | |
271 | .detach_client = &pcf8563_detach, | |
272 | }; | |
273 | ||
274 | static int pcf8563_probe(struct i2c_adapter *adapter, int address, int kind) | |
275 | { | |
cbb94502 | 276 | struct pcf8563 *pcf8563; |
b5a82d62 AZ |
277 | struct i2c_client *client; |
278 | struct rtc_device *rtc; | |
279 | ||
280 | int err = 0; | |
281 | ||
5dd3ffae | 282 | dev_dbg(&adapter->dev, "%s\n", __FUNCTION__); |
b5a82d62 AZ |
283 | |
284 | if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) { | |
285 | err = -ENODEV; | |
286 | goto exit; | |
287 | } | |
288 | ||
cbb94502 | 289 | if (!(pcf8563 = kzalloc(sizeof(struct pcf8563), GFP_KERNEL))) { |
b5a82d62 AZ |
290 | err = -ENOMEM; |
291 | goto exit; | |
292 | } | |
293 | ||
cbb94502 | 294 | client = &pcf8563->client; |
b5a82d62 AZ |
295 | client->addr = address; |
296 | client->driver = &pcf8563_driver; | |
297 | client->adapter = adapter; | |
298 | ||
299 | strlcpy(client->name, pcf8563_driver.driver.name, I2C_NAME_SIZE); | |
300 | ||
301 | /* Verify the chip is really an PCF8563 */ | |
302 | if (kind < 0) { | |
303 | if (pcf8563_validate_client(client) < 0) { | |
304 | err = -ENODEV; | |
305 | goto exit_kfree; | |
306 | } | |
307 | } | |
308 | ||
309 | /* Inform the i2c layer */ | |
310 | if ((err = i2c_attach_client(client))) | |
311 | goto exit_kfree; | |
312 | ||
313 | dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); | |
314 | ||
315 | rtc = rtc_device_register(pcf8563_driver.driver.name, &client->dev, | |
316 | &pcf8563_rtc_ops, THIS_MODULE); | |
317 | ||
318 | if (IS_ERR(rtc)) { | |
319 | err = PTR_ERR(rtc); | |
b5a82d62 AZ |
320 | goto exit_detach; |
321 | } | |
322 | ||
323 | i2c_set_clientdata(client, rtc); | |
324 | ||
325 | return 0; | |
326 | ||
327 | exit_detach: | |
328 | i2c_detach_client(client); | |
329 | ||
330 | exit_kfree: | |
cbb94502 | 331 | kfree(pcf8563); |
b5a82d62 AZ |
332 | |
333 | exit: | |
334 | return err; | |
335 | } | |
336 | ||
337 | static int pcf8563_detach(struct i2c_client *client) | |
338 | { | |
cbb94502 | 339 | struct pcf8563 *pcf8563 = container_of(client, struct pcf8563, client); |
b5a82d62 AZ |
340 | int err; |
341 | struct rtc_device *rtc = i2c_get_clientdata(client); | |
342 | ||
b5a82d62 AZ |
343 | if (rtc) |
344 | rtc_device_unregister(rtc); | |
345 | ||
346 | if ((err = i2c_detach_client(client))) | |
347 | return err; | |
348 | ||
cbb94502 | 349 | kfree(pcf8563); |
b5a82d62 AZ |
350 | |
351 | return 0; | |
352 | } | |
353 | ||
354 | static int __init pcf8563_init(void) | |
355 | { | |
356 | return i2c_add_driver(&pcf8563_driver); | |
357 | } | |
358 | ||
359 | static void __exit pcf8563_exit(void) | |
360 | { | |
361 | i2c_del_driver(&pcf8563_driver); | |
362 | } | |
363 | ||
364 | MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); | |
365 | MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver"); | |
366 | MODULE_LICENSE("GPL"); | |
367 | MODULE_VERSION(DRV_VERSION); | |
368 | ||
369 | module_init(pcf8563_init); | |
370 | module_exit(pcf8563_exit); |