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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 | ||
56 | static int pcf8563_probe(struct i2c_adapter *adapter, int address, int kind); | |
57 | static int pcf8563_detach(struct i2c_client *client); | |
58 | ||
59 | /* | |
60 | * In the routines that deal directly with the pcf8563 hardware, we use | |
61 | * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. | |
62 | */ | |
63 | static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm) | |
64 | { | |
65 | unsigned char buf[13] = { PCF8563_REG_ST1 }; | |
66 | ||
67 | struct i2c_msg msgs[] = { | |
68 | { client->addr, 0, 1, buf }, /* setup read ptr */ | |
69 | { client->addr, I2C_M_RD, 13, buf }, /* read status + date */ | |
70 | }; | |
71 | ||
72 | /* read registers */ | |
73 | if ((i2c_transfer(client->adapter, msgs, 2)) != 2) { | |
74 | dev_err(&client->dev, "%s: read error\n", __FUNCTION__); | |
75 | return -EIO; | |
76 | } | |
77 | ||
78 | if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) | |
79 | dev_info(&client->dev, | |
80 | "low voltage detected, date/time is not reliable.\n"); | |
81 | ||
82 | dev_dbg(&client->dev, | |
83 | "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, " | |
84 | "mday=%02x, wday=%02x, mon=%02x, year=%02x\n", | |
85 | __FUNCTION__, | |
86 | buf[0], buf[1], buf[2], buf[3], | |
87 | buf[4], buf[5], buf[6], buf[7], | |
88 | buf[8]); | |
89 | ||
90 | ||
91 | tm->tm_sec = BCD2BIN(buf[PCF8563_REG_SC] & 0x7F); | |
92 | tm->tm_min = BCD2BIN(buf[PCF8563_REG_MN] & 0x7F); | |
93 | tm->tm_hour = BCD2BIN(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */ | |
94 | tm->tm_mday = BCD2BIN(buf[PCF8563_REG_DM] & 0x3F); | |
95 | tm->tm_wday = buf[PCF8563_REG_DW] & 0x07; | |
96 | tm->tm_mon = BCD2BIN(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */ | |
97 | tm->tm_year = BCD2BIN(buf[PCF8563_REG_YR]) | |
98 | + (buf[PCF8563_REG_MO] & PCF8563_MO_C ? 100 : 0); | |
99 | ||
100 | dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " | |
101 | "mday=%d, mon=%d, year=%d, wday=%d\n", | |
102 | __FUNCTION__, | |
103 | tm->tm_sec, tm->tm_min, tm->tm_hour, | |
104 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); | |
105 | ||
106 | /* the clock can give out invalid datetime, but we cannot return | |
107 | * -EINVAL otherwise hwclock will refuse to set the time on bootup. | |
108 | */ | |
109 | if (rtc_valid_tm(tm) < 0) | |
110 | dev_err(&client->dev, "retrieved date/time is not valid.\n"); | |
111 | ||
112 | return 0; | |
113 | } | |
114 | ||
115 | static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm) | |
116 | { | |
117 | int i, err; | |
118 | unsigned char buf[9]; | |
119 | ||
120 | dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, " | |
121 | "mday=%d, mon=%d, year=%d, wday=%d\n", | |
122 | __FUNCTION__, | |
123 | tm->tm_sec, tm->tm_min, tm->tm_hour, | |
124 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); | |
125 | ||
126 | /* hours, minutes and seconds */ | |
127 | buf[PCF8563_REG_SC] = BIN2BCD(tm->tm_sec); | |
128 | buf[PCF8563_REG_MN] = BIN2BCD(tm->tm_min); | |
129 | buf[PCF8563_REG_HR] = BIN2BCD(tm->tm_hour); | |
130 | ||
131 | buf[PCF8563_REG_DM] = BIN2BCD(tm->tm_mday); | |
132 | ||
133 | /* month, 1 - 12 */ | |
134 | buf[PCF8563_REG_MO] = BIN2BCD(tm->tm_mon + 1); | |
135 | ||
136 | /* year and century */ | |
137 | buf[PCF8563_REG_YR] = BIN2BCD(tm->tm_year % 100); | |
138 | if (tm->tm_year / 100) | |
139 | buf[PCF8563_REG_MO] |= PCF8563_MO_C; | |
140 | ||
141 | buf[PCF8563_REG_DW] = tm->tm_wday & 0x07; | |
142 | ||
143 | /* write register's data */ | |
144 | for (i = 0; i < 7; i++) { | |
145 | unsigned char data[2] = { PCF8563_REG_SC + i, | |
146 | buf[PCF8563_REG_SC + i] }; | |
147 | ||
148 | err = i2c_master_send(client, data, sizeof(data)); | |
149 | if (err != sizeof(data)) { | |
150 | dev_err(&client->dev, | |
151 | "%s: err=%d addr=%02x, data=%02x\n", | |
152 | __FUNCTION__, err, data[0], data[1]); | |
153 | return -EIO; | |
154 | } | |
155 | }; | |
156 | ||
157 | return 0; | |
158 | } | |
159 | ||
160 | struct pcf8563_limit | |
161 | { | |
162 | unsigned char reg; | |
163 | unsigned char mask; | |
164 | unsigned char min; | |
165 | unsigned char max; | |
166 | }; | |
167 | ||
168 | static int pcf8563_validate_client(struct i2c_client *client) | |
169 | { | |
170 | int i; | |
171 | ||
172 | static const struct pcf8563_limit pattern[] = { | |
173 | /* register, mask, min, max */ | |
174 | { PCF8563_REG_SC, 0x7F, 0, 59 }, | |
175 | { PCF8563_REG_MN, 0x7F, 0, 59 }, | |
176 | { PCF8563_REG_HR, 0x3F, 0, 23 }, | |
177 | { PCF8563_REG_DM, 0x3F, 0, 31 }, | |
178 | { PCF8563_REG_MO, 0x1F, 0, 12 }, | |
179 | }; | |
180 | ||
181 | /* check limits (only registers with bcd values) */ | |
182 | for (i = 0; i < ARRAY_SIZE(pattern); i++) { | |
183 | int xfer; | |
184 | unsigned char value; | |
185 | unsigned char buf = pattern[i].reg; | |
186 | ||
187 | struct i2c_msg msgs[] = { | |
188 | { client->addr, 0, 1, &buf }, | |
189 | { client->addr, I2C_M_RD, 1, &buf }, | |
190 | }; | |
191 | ||
192 | xfer = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); | |
193 | ||
194 | if (xfer != ARRAY_SIZE(msgs)) { | |
195 | dev_err(&client->adapter->dev, | |
196 | "%s: could not read register 0x%02X\n", | |
197 | __FUNCTION__, pattern[i].reg); | |
198 | ||
199 | return -EIO; | |
200 | } | |
201 | ||
202 | value = BCD2BIN(buf & pattern[i].mask); | |
203 | ||
204 | if (value > pattern[i].max || | |
205 | value < pattern[i].min) { | |
206 | dev_dbg(&client->adapter->dev, | |
207 | "%s: pattern=%d, reg=%x, mask=0x%02x, min=%d, " | |
208 | "max=%d, value=%d, raw=0x%02X\n", | |
209 | __FUNCTION__, i, pattern[i].reg, pattern[i].mask, | |
210 | pattern[i].min, pattern[i].max, | |
211 | value, buf); | |
212 | ||
213 | return -ENODEV; | |
214 | } | |
215 | } | |
216 | ||
217 | return 0; | |
218 | } | |
219 | ||
220 | static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
221 | { | |
222 | return pcf8563_get_datetime(to_i2c_client(dev), tm); | |
223 | } | |
224 | ||
225 | static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
226 | { | |
227 | return pcf8563_set_datetime(to_i2c_client(dev), tm); | |
228 | } | |
229 | ||
230 | static int pcf8563_rtc_proc(struct device *dev, struct seq_file *seq) | |
231 | { | |
232 | seq_printf(seq, "24hr\t\t: yes\n"); | |
233 | return 0; | |
234 | } | |
235 | ||
236 | static struct rtc_class_ops pcf8563_rtc_ops = { | |
237 | .proc = pcf8563_rtc_proc, | |
238 | .read_time = pcf8563_rtc_read_time, | |
239 | .set_time = pcf8563_rtc_set_time, | |
240 | }; | |
241 | ||
242 | static int pcf8563_attach(struct i2c_adapter *adapter) | |
243 | { | |
244 | return i2c_probe(adapter, &addr_data, pcf8563_probe); | |
245 | } | |
246 | ||
247 | static struct i2c_driver pcf8563_driver = { | |
248 | .driver = { | |
249 | .name = "pcf8563", | |
250 | }, | |
251 | .id = I2C_DRIVERID_PCF8563, | |
252 | .attach_adapter = &pcf8563_attach, | |
253 | .detach_client = &pcf8563_detach, | |
254 | }; | |
255 | ||
256 | static int pcf8563_probe(struct i2c_adapter *adapter, int address, int kind) | |
257 | { | |
258 | struct i2c_client *client; | |
259 | struct rtc_device *rtc; | |
260 | ||
261 | int err = 0; | |
262 | ||
263 | dev_dbg(&adapter->dev, "%s\n", __FUNCTION__); | |
264 | ||
265 | if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) { | |
266 | err = -ENODEV; | |
267 | goto exit; | |
268 | } | |
269 | ||
270 | if (!(client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL))) { | |
271 | err = -ENOMEM; | |
272 | goto exit; | |
273 | } | |
274 | ||
275 | client->addr = address; | |
276 | client->driver = &pcf8563_driver; | |
277 | client->adapter = adapter; | |
278 | ||
279 | strlcpy(client->name, pcf8563_driver.driver.name, I2C_NAME_SIZE); | |
280 | ||
281 | /* Verify the chip is really an PCF8563 */ | |
282 | if (kind < 0) { | |
283 | if (pcf8563_validate_client(client) < 0) { | |
284 | err = -ENODEV; | |
285 | goto exit_kfree; | |
286 | } | |
287 | } | |
288 | ||
289 | /* Inform the i2c layer */ | |
290 | if ((err = i2c_attach_client(client))) | |
291 | goto exit_kfree; | |
292 | ||
293 | dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); | |
294 | ||
295 | rtc = rtc_device_register(pcf8563_driver.driver.name, &client->dev, | |
296 | &pcf8563_rtc_ops, THIS_MODULE); | |
297 | ||
298 | if (IS_ERR(rtc)) { | |
299 | err = PTR_ERR(rtc); | |
300 | dev_err(&client->dev, | |
301 | "unable to register the class device\n"); | |
302 | goto exit_detach; | |
303 | } | |
304 | ||
305 | i2c_set_clientdata(client, rtc); | |
306 | ||
307 | return 0; | |
308 | ||
309 | exit_detach: | |
310 | i2c_detach_client(client); | |
311 | ||
312 | exit_kfree: | |
313 | kfree(client); | |
314 | ||
315 | exit: | |
316 | return err; | |
317 | } | |
318 | ||
319 | static int pcf8563_detach(struct i2c_client *client) | |
320 | { | |
321 | int err; | |
322 | struct rtc_device *rtc = i2c_get_clientdata(client); | |
323 | ||
324 | dev_dbg(&client->dev, "%s\n", __FUNCTION__); | |
325 | ||
326 | if (rtc) | |
327 | rtc_device_unregister(rtc); | |
328 | ||
329 | if ((err = i2c_detach_client(client))) | |
330 | return err; | |
331 | ||
332 | kfree(client); | |
333 | ||
334 | return 0; | |
335 | } | |
336 | ||
337 | static int __init pcf8563_init(void) | |
338 | { | |
339 | return i2c_add_driver(&pcf8563_driver); | |
340 | } | |
341 | ||
342 | static void __exit pcf8563_exit(void) | |
343 | { | |
344 | i2c_del_driver(&pcf8563_driver); | |
345 | } | |
346 | ||
347 | MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); | |
348 | MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver"); | |
349 | MODULE_LICENSE("GPL"); | |
350 | MODULE_VERSION(DRV_VERSION); | |
351 | ||
352 | module_init(pcf8563_init); | |
353 | module_exit(pcf8563_exit); |