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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 | ||
e5fc9cc0 | 21 | #define DRV_VERSION "0.4.3" |
b5a82d62 AZ |
22 | |
23 | #define PCF8563_REG_ST1 0x00 /* status */ | |
24 | #define PCF8563_REG_ST2 0x01 | |
25 | ||
26 | #define PCF8563_REG_SC 0x02 /* datetime */ | |
27 | #define PCF8563_REG_MN 0x03 | |
28 | #define PCF8563_REG_HR 0x04 | |
29 | #define PCF8563_REG_DM 0x05 | |
30 | #define PCF8563_REG_DW 0x06 | |
31 | #define PCF8563_REG_MO 0x07 | |
32 | #define PCF8563_REG_YR 0x08 | |
33 | ||
34 | #define PCF8563_REG_AMN 0x09 /* alarm */ | |
35 | #define PCF8563_REG_AHR 0x0A | |
36 | #define PCF8563_REG_ADM 0x0B | |
37 | #define PCF8563_REG_ADW 0x0C | |
38 | ||
39 | #define PCF8563_REG_CLKO 0x0D /* clock out */ | |
40 | #define PCF8563_REG_TMRC 0x0E /* timer control */ | |
41 | #define PCF8563_REG_TMR 0x0F /* timer */ | |
42 | ||
43 | #define PCF8563_SC_LV 0x80 /* low voltage */ | |
44 | #define PCF8563_MO_C 0x80 /* century */ | |
45 | ||
e5fc9cc0 AZ |
46 | static struct i2c_driver pcf8563_driver; |
47 | ||
cbb94502 | 48 | struct pcf8563 { |
e5fc9cc0 | 49 | struct rtc_device *rtc; |
cbb94502 AN |
50 | /* |
51 | * The meaning of MO_C bit varies by the chip type. | |
52 | * From PCF8563 datasheet: this bit is toggled when the years | |
53 | * register overflows from 99 to 00 | |
54 | * 0 indicates the century is 20xx | |
55 | * 1 indicates the century is 19xx | |
56 | * From RTC8564 datasheet: this bit indicates change of | |
57 | * century. When the year digit data overflows from 99 to 00, | |
58 | * this bit is set. By presetting it to 0 while still in the | |
59 | * 20th century, it will be set in year 2000, ... | |
60 | * There seems no reliable way to know how the system use this | |
61 | * bit. So let's do it heuristically, assuming we are live in | |
62 | * 1970...2069. | |
63 | */ | |
64 | int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */ | |
65 | }; | |
66 | ||
b5a82d62 AZ |
67 | /* |
68 | * In the routines that deal directly with the pcf8563 hardware, we use | |
69 | * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. | |
70 | */ | |
71 | static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm) | |
72 | { | |
e5fc9cc0 | 73 | struct pcf8563 *pcf8563 = i2c_get_clientdata(client); |
b5a82d62 AZ |
74 | unsigned char buf[13] = { PCF8563_REG_ST1 }; |
75 | ||
76 | struct i2c_msg msgs[] = { | |
77 | { client->addr, 0, 1, buf }, /* setup read ptr */ | |
78 | { client->addr, I2C_M_RD, 13, buf }, /* read status + date */ | |
79 | }; | |
80 | ||
81 | /* read registers */ | |
82 | if ((i2c_transfer(client->adapter, msgs, 2)) != 2) { | |
2a4e2b87 | 83 | dev_err(&client->dev, "%s: read error\n", __func__); |
b5a82d62 AZ |
84 | return -EIO; |
85 | } | |
86 | ||
87 | if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) | |
88 | dev_info(&client->dev, | |
89 | "low voltage detected, date/time is not reliable.\n"); | |
90 | ||
91 | dev_dbg(&client->dev, | |
92 | "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, " | |
93 | "mday=%02x, wday=%02x, mon=%02x, year=%02x\n", | |
2a4e2b87 | 94 | __func__, |
b5a82d62 AZ |
95 | buf[0], buf[1], buf[2], buf[3], |
96 | buf[4], buf[5], buf[6], buf[7], | |
97 | buf[8]); | |
98 | ||
99 | ||
100 | tm->tm_sec = BCD2BIN(buf[PCF8563_REG_SC] & 0x7F); | |
101 | tm->tm_min = BCD2BIN(buf[PCF8563_REG_MN] & 0x7F); | |
102 | tm->tm_hour = BCD2BIN(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */ | |
103 | tm->tm_mday = BCD2BIN(buf[PCF8563_REG_DM] & 0x3F); | |
104 | tm->tm_wday = buf[PCF8563_REG_DW] & 0x07; | |
105 | tm->tm_mon = BCD2BIN(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */ | |
cbb94502 AN |
106 | tm->tm_year = BCD2BIN(buf[PCF8563_REG_YR]); |
107 | if (tm->tm_year < 70) | |
108 | tm->tm_year += 100; /* assume we are in 1970...2069 */ | |
109 | /* detect the polarity heuristically. see note above. */ | |
110 | pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ? | |
111 | (tm->tm_year >= 100) : (tm->tm_year < 100); | |
b5a82d62 AZ |
112 | |
113 | dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " | |
114 | "mday=%d, mon=%d, year=%d, wday=%d\n", | |
2a4e2b87 | 115 | __func__, |
b5a82d62 AZ |
116 | tm->tm_sec, tm->tm_min, tm->tm_hour, |
117 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); | |
118 | ||
119 | /* the clock can give out invalid datetime, but we cannot return | |
120 | * -EINVAL otherwise hwclock will refuse to set the time on bootup. | |
121 | */ | |
122 | if (rtc_valid_tm(tm) < 0) | |
123 | dev_err(&client->dev, "retrieved date/time is not valid.\n"); | |
124 | ||
125 | return 0; | |
126 | } | |
127 | ||
128 | static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm) | |
129 | { | |
e5fc9cc0 | 130 | struct pcf8563 *pcf8563 = i2c_get_clientdata(client); |
b5a82d62 AZ |
131 | int i, err; |
132 | unsigned char buf[9]; | |
133 | ||
134 | dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, " | |
135 | "mday=%d, mon=%d, year=%d, wday=%d\n", | |
2a4e2b87 | 136 | __func__, |
b5a82d62 AZ |
137 | tm->tm_sec, tm->tm_min, tm->tm_hour, |
138 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); | |
139 | ||
140 | /* hours, minutes and seconds */ | |
141 | buf[PCF8563_REG_SC] = BIN2BCD(tm->tm_sec); | |
142 | buf[PCF8563_REG_MN] = BIN2BCD(tm->tm_min); | |
143 | buf[PCF8563_REG_HR] = BIN2BCD(tm->tm_hour); | |
144 | ||
145 | buf[PCF8563_REG_DM] = BIN2BCD(tm->tm_mday); | |
146 | ||
147 | /* month, 1 - 12 */ | |
148 | buf[PCF8563_REG_MO] = BIN2BCD(tm->tm_mon + 1); | |
149 | ||
150 | /* year and century */ | |
151 | buf[PCF8563_REG_YR] = BIN2BCD(tm->tm_year % 100); | |
cbb94502 | 152 | if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100)) |
b5a82d62 AZ |
153 | buf[PCF8563_REG_MO] |= PCF8563_MO_C; |
154 | ||
155 | buf[PCF8563_REG_DW] = tm->tm_wday & 0x07; | |
156 | ||
157 | /* write register's data */ | |
158 | for (i = 0; i < 7; i++) { | |
159 | unsigned char data[2] = { PCF8563_REG_SC + i, | |
160 | buf[PCF8563_REG_SC + i] }; | |
161 | ||
162 | err = i2c_master_send(client, data, sizeof(data)); | |
163 | if (err != sizeof(data)) { | |
164 | dev_err(&client->dev, | |
165 | "%s: err=%d addr=%02x, data=%02x\n", | |
2a4e2b87 | 166 | __func__, err, data[0], data[1]); |
b5a82d62 AZ |
167 | return -EIO; |
168 | } | |
169 | }; | |
170 | ||
171 | return 0; | |
172 | } | |
173 | ||
174 | struct pcf8563_limit | |
175 | { | |
176 | unsigned char reg; | |
177 | unsigned char mask; | |
178 | unsigned char min; | |
179 | unsigned char max; | |
180 | }; | |
181 | ||
182 | static int pcf8563_validate_client(struct i2c_client *client) | |
183 | { | |
184 | int i; | |
185 | ||
186 | static const struct pcf8563_limit pattern[] = { | |
187 | /* register, mask, min, max */ | |
188 | { PCF8563_REG_SC, 0x7F, 0, 59 }, | |
189 | { PCF8563_REG_MN, 0x7F, 0, 59 }, | |
190 | { PCF8563_REG_HR, 0x3F, 0, 23 }, | |
191 | { PCF8563_REG_DM, 0x3F, 0, 31 }, | |
192 | { PCF8563_REG_MO, 0x1F, 0, 12 }, | |
193 | }; | |
194 | ||
195 | /* check limits (only registers with bcd values) */ | |
196 | for (i = 0; i < ARRAY_SIZE(pattern); i++) { | |
197 | int xfer; | |
198 | unsigned char value; | |
199 | unsigned char buf = pattern[i].reg; | |
200 | ||
201 | struct i2c_msg msgs[] = { | |
202 | { client->addr, 0, 1, &buf }, | |
203 | { client->addr, I2C_M_RD, 1, &buf }, | |
204 | }; | |
205 | ||
206 | xfer = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); | |
207 | ||
208 | if (xfer != ARRAY_SIZE(msgs)) { | |
a14e1893 | 209 | dev_err(&client->dev, |
b5a82d62 | 210 | "%s: could not read register 0x%02X\n", |
2a4e2b87 | 211 | __func__, pattern[i].reg); |
b5a82d62 AZ |
212 | |
213 | return -EIO; | |
214 | } | |
215 | ||
216 | value = BCD2BIN(buf & pattern[i].mask); | |
217 | ||
218 | if (value > pattern[i].max || | |
219 | value < pattern[i].min) { | |
a14e1893 | 220 | dev_dbg(&client->dev, |
b5a82d62 AZ |
221 | "%s: pattern=%d, reg=%x, mask=0x%02x, min=%d, " |
222 | "max=%d, value=%d, raw=0x%02X\n", | |
2a4e2b87 | 223 | __func__, i, pattern[i].reg, pattern[i].mask, |
b5a82d62 AZ |
224 | pattern[i].min, pattern[i].max, |
225 | value, buf); | |
226 | ||
227 | return -ENODEV; | |
228 | } | |
229 | } | |
230 | ||
231 | return 0; | |
232 | } | |
233 | ||
234 | static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
235 | { | |
236 | return pcf8563_get_datetime(to_i2c_client(dev), tm); | |
237 | } | |
238 | ||
239 | static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
240 | { | |
241 | return pcf8563_set_datetime(to_i2c_client(dev), tm); | |
242 | } | |
243 | ||
ff8371ac | 244 | static const struct rtc_class_ops pcf8563_rtc_ops = { |
b5a82d62 AZ |
245 | .read_time = pcf8563_rtc_read_time, |
246 | .set_time = pcf8563_rtc_set_time, | |
247 | }; | |
248 | ||
e5fc9cc0 | 249 | static int pcf8563_probe(struct i2c_client *client) |
b5a82d62 | 250 | { |
cbb94502 | 251 | struct pcf8563 *pcf8563; |
b5a82d62 AZ |
252 | |
253 | int err = 0; | |
254 | ||
e5fc9cc0 | 255 | dev_dbg(&client->dev, "%s\n", __func__); |
b5a82d62 | 256 | |
e5fc9cc0 AZ |
257 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) |
258 | return -ENODEV; | |
b5a82d62 | 259 | |
e5fc9cc0 AZ |
260 | pcf8563 = kzalloc(sizeof(struct pcf8563), GFP_KERNEL); |
261 | if (!pcf8563) | |
262 | return -ENOMEM; | |
b5a82d62 AZ |
263 | |
264 | /* Verify the chip is really an PCF8563 */ | |
e5fc9cc0 AZ |
265 | if (pcf8563_validate_client(client) < 0) { |
266 | err = -ENODEV; | |
b5a82d62 | 267 | goto exit_kfree; |
e5fc9cc0 | 268 | } |
b5a82d62 AZ |
269 | |
270 | dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); | |
271 | ||
e5fc9cc0 AZ |
272 | pcf8563->rtc = rtc_device_register(pcf8563_driver.driver.name, |
273 | &client->dev, &pcf8563_rtc_ops, THIS_MODULE); | |
b5a82d62 | 274 | |
e5fc9cc0 AZ |
275 | if (IS_ERR(pcf8563->rtc)) { |
276 | err = PTR_ERR(pcf8563->rtc); | |
277 | goto exit_kfree; | |
b5a82d62 AZ |
278 | } |
279 | ||
e5fc9cc0 | 280 | i2c_set_clientdata(client, pcf8563); |
b5a82d62 AZ |
281 | |
282 | return 0; | |
283 | ||
b5a82d62 | 284 | exit_kfree: |
cbb94502 | 285 | kfree(pcf8563); |
b5a82d62 | 286 | |
b5a82d62 AZ |
287 | return err; |
288 | } | |
289 | ||
e5fc9cc0 | 290 | static int pcf8563_remove(struct i2c_client *client) |
b5a82d62 | 291 | { |
e5fc9cc0 | 292 | struct pcf8563 *pcf8563 = i2c_get_clientdata(client); |
b5a82d62 | 293 | |
e5fc9cc0 AZ |
294 | if (pcf8563->rtc) |
295 | rtc_device_unregister(pcf8563->rtc); | |
b5a82d62 | 296 | |
cbb94502 | 297 | kfree(pcf8563); |
b5a82d62 AZ |
298 | |
299 | return 0; | |
300 | } | |
301 | ||
e5fc9cc0 AZ |
302 | static struct i2c_driver pcf8563_driver = { |
303 | .driver = { | |
304 | .name = "rtc-pcf8563", | |
305 | }, | |
306 | .probe = pcf8563_probe, | |
307 | .remove = pcf8563_remove, | |
308 | }; | |
309 | ||
b5a82d62 AZ |
310 | static int __init pcf8563_init(void) |
311 | { | |
312 | return i2c_add_driver(&pcf8563_driver); | |
313 | } | |
314 | ||
315 | static void __exit pcf8563_exit(void) | |
316 | { | |
317 | i2c_del_driver(&pcf8563_driver); | |
318 | } | |
319 | ||
320 | MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); | |
321 | MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver"); | |
322 | MODULE_LICENSE("GPL"); | |
323 | MODULE_VERSION(DRV_VERSION); | |
324 | ||
325 | module_init(pcf8563_init); | |
326 | module_exit(pcf8563_exit); |