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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> | |
5a0e3ad6 | 20 | #include <linux/slab.h> |
2113852b | 21 | #include <linux/module.h> |
8dccaf06 | 22 | #include <linux/of.h> |
b5a82d62 | 23 | |
e5fc9cc0 | 24 | #define DRV_VERSION "0.4.3" |
b5a82d62 AZ |
25 | |
26 | #define PCF8563_REG_ST1 0x00 /* status */ | |
27 | #define PCF8563_REG_ST2 0x01 | |
28 | ||
29 | #define PCF8563_REG_SC 0x02 /* datetime */ | |
30 | #define PCF8563_REG_MN 0x03 | |
31 | #define PCF8563_REG_HR 0x04 | |
32 | #define PCF8563_REG_DM 0x05 | |
33 | #define PCF8563_REG_DW 0x06 | |
34 | #define PCF8563_REG_MO 0x07 | |
35 | #define PCF8563_REG_YR 0x08 | |
36 | ||
37 | #define PCF8563_REG_AMN 0x09 /* alarm */ | |
38 | #define PCF8563_REG_AHR 0x0A | |
39 | #define PCF8563_REG_ADM 0x0B | |
40 | #define PCF8563_REG_ADW 0x0C | |
41 | ||
42 | #define PCF8563_REG_CLKO 0x0D /* clock out */ | |
43 | #define PCF8563_REG_TMRC 0x0E /* timer control */ | |
44 | #define PCF8563_REG_TMR 0x0F /* timer */ | |
45 | ||
46 | #define PCF8563_SC_LV 0x80 /* low voltage */ | |
47 | #define PCF8563_MO_C 0x80 /* century */ | |
48 | ||
e5fc9cc0 AZ |
49 | static struct i2c_driver pcf8563_driver; |
50 | ||
cbb94502 | 51 | struct pcf8563 { |
e5fc9cc0 | 52 | struct rtc_device *rtc; |
cbb94502 AN |
53 | /* |
54 | * The meaning of MO_C bit varies by the chip type. | |
55 | * From PCF8563 datasheet: this bit is toggled when the years | |
56 | * register overflows from 99 to 00 | |
57 | * 0 indicates the century is 20xx | |
58 | * 1 indicates the century is 19xx | |
59 | * From RTC8564 datasheet: this bit indicates change of | |
60 | * century. When the year digit data overflows from 99 to 00, | |
61 | * this bit is set. By presetting it to 0 while still in the | |
62 | * 20th century, it will be set in year 2000, ... | |
63 | * There seems no reliable way to know how the system use this | |
64 | * bit. So let's do it heuristically, assuming we are live in | |
65 | * 1970...2069. | |
66 | */ | |
67 | int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */ | |
0f20b767 | 68 | int voltage_low; /* incicates if a low_voltage was detected */ |
cbb94502 AN |
69 | }; |
70 | ||
b5a82d62 AZ |
71 | /* |
72 | * In the routines that deal directly with the pcf8563 hardware, we use | |
73 | * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. | |
74 | */ | |
75 | static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm) | |
76 | { | |
e5fc9cc0 | 77 | struct pcf8563 *pcf8563 = i2c_get_clientdata(client); |
b5a82d62 AZ |
78 | unsigned char buf[13] = { PCF8563_REG_ST1 }; |
79 | ||
80 | struct i2c_msg msgs[] = { | |
81 | { client->addr, 0, 1, buf }, /* setup read ptr */ | |
82 | { client->addr, I2C_M_RD, 13, buf }, /* read status + date */ | |
83 | }; | |
84 | ||
85 | /* read registers */ | |
86 | if ((i2c_transfer(client->adapter, msgs, 2)) != 2) { | |
2a4e2b87 | 87 | dev_err(&client->dev, "%s: read error\n", __func__); |
b5a82d62 AZ |
88 | return -EIO; |
89 | } | |
90 | ||
0f20b767 AS |
91 | if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) { |
92 | pcf8563->voltage_low = 1; | |
b5a82d62 AZ |
93 | dev_info(&client->dev, |
94 | "low voltage detected, date/time is not reliable.\n"); | |
0f20b767 | 95 | } |
b5a82d62 AZ |
96 | |
97 | dev_dbg(&client->dev, | |
98 | "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, " | |
99 | "mday=%02x, wday=%02x, mon=%02x, year=%02x\n", | |
2a4e2b87 | 100 | __func__, |
b5a82d62 AZ |
101 | buf[0], buf[1], buf[2], buf[3], |
102 | buf[4], buf[5], buf[6], buf[7], | |
103 | buf[8]); | |
104 | ||
105 | ||
fe20ba70 AB |
106 | tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F); |
107 | tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F); | |
108 | tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */ | |
109 | tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F); | |
b5a82d62 | 110 | tm->tm_wday = buf[PCF8563_REG_DW] & 0x07; |
fe20ba70 AB |
111 | tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */ |
112 | tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]); | |
cbb94502 AN |
113 | if (tm->tm_year < 70) |
114 | tm->tm_year += 100; /* assume we are in 1970...2069 */ | |
115 | /* detect the polarity heuristically. see note above. */ | |
116 | pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ? | |
117 | (tm->tm_year >= 100) : (tm->tm_year < 100); | |
b5a82d62 AZ |
118 | |
119 | dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " | |
120 | "mday=%d, mon=%d, year=%d, wday=%d\n", | |
2a4e2b87 | 121 | __func__, |
b5a82d62 AZ |
122 | tm->tm_sec, tm->tm_min, tm->tm_hour, |
123 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); | |
124 | ||
125 | /* the clock can give out invalid datetime, but we cannot return | |
126 | * -EINVAL otherwise hwclock will refuse to set the time on bootup. | |
127 | */ | |
128 | if (rtc_valid_tm(tm) < 0) | |
129 | dev_err(&client->dev, "retrieved date/time is not valid.\n"); | |
130 | ||
131 | return 0; | |
132 | } | |
133 | ||
134 | static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm) | |
135 | { | |
e5fc9cc0 | 136 | struct pcf8563 *pcf8563 = i2c_get_clientdata(client); |
b5a82d62 AZ |
137 | int i, err; |
138 | unsigned char buf[9]; | |
139 | ||
140 | dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, " | |
141 | "mday=%d, mon=%d, year=%d, wday=%d\n", | |
2a4e2b87 | 142 | __func__, |
b5a82d62 AZ |
143 | tm->tm_sec, tm->tm_min, tm->tm_hour, |
144 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); | |
145 | ||
146 | /* hours, minutes and seconds */ | |
fe20ba70 AB |
147 | buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec); |
148 | buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min); | |
149 | buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour); | |
b5a82d62 | 150 | |
fe20ba70 | 151 | buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday); |
b5a82d62 AZ |
152 | |
153 | /* month, 1 - 12 */ | |
fe20ba70 | 154 | buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1); |
b5a82d62 AZ |
155 | |
156 | /* year and century */ | |
fe20ba70 | 157 | buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100); |
cbb94502 | 158 | if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100)) |
b5a82d62 AZ |
159 | buf[PCF8563_REG_MO] |= PCF8563_MO_C; |
160 | ||
161 | buf[PCF8563_REG_DW] = tm->tm_wday & 0x07; | |
162 | ||
163 | /* write register's data */ | |
164 | for (i = 0; i < 7; i++) { | |
165 | unsigned char data[2] = { PCF8563_REG_SC + i, | |
166 | buf[PCF8563_REG_SC + i] }; | |
167 | ||
168 | err = i2c_master_send(client, data, sizeof(data)); | |
169 | if (err != sizeof(data)) { | |
170 | dev_err(&client->dev, | |
171 | "%s: err=%d addr=%02x, data=%02x\n", | |
2a4e2b87 | 172 | __func__, err, data[0], data[1]); |
b5a82d62 AZ |
173 | return -EIO; |
174 | } | |
175 | }; | |
176 | ||
177 | return 0; | |
178 | } | |
179 | ||
0f20b767 AS |
180 | #ifdef CONFIG_RTC_INTF_DEV |
181 | static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) | |
182 | { | |
183 | struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev)); | |
184 | struct rtc_time tm; | |
185 | ||
186 | switch (cmd) { | |
187 | case RTC_VL_READ: | |
188 | if (pcf8563->voltage_low) | |
189 | dev_info(dev, "low voltage detected, date/time is not reliable.\n"); | |
190 | ||
191 | if (copy_to_user((void __user *)arg, &pcf8563->voltage_low, | |
192 | sizeof(int))) | |
193 | return -EFAULT; | |
194 | return 0; | |
195 | case RTC_VL_CLR: | |
196 | /* | |
197 | * Clear the VL bit in the seconds register in case | |
198 | * the time has not been set already (which would | |
199 | * have cleared it). This does not really matter | |
200 | * because of the cached voltage_low value but do it | |
201 | * anyway for consistency. | |
202 | */ | |
203 | if (pcf8563_get_datetime(to_i2c_client(dev), &tm)) | |
204 | pcf8563_set_datetime(to_i2c_client(dev), &tm); | |
205 | ||
206 | /* Clear the cached value. */ | |
207 | pcf8563->voltage_low = 0; | |
208 | ||
209 | return 0; | |
210 | default: | |
211 | return -ENOIOCTLCMD; | |
212 | } | |
213 | } | |
214 | #else | |
215 | #define pcf8563_rtc_ioctl NULL | |
216 | #endif | |
217 | ||
b5a82d62 AZ |
218 | static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm) |
219 | { | |
220 | return pcf8563_get_datetime(to_i2c_client(dev), tm); | |
221 | } | |
222 | ||
223 | static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
224 | { | |
225 | return pcf8563_set_datetime(to_i2c_client(dev), tm); | |
226 | } | |
227 | ||
ff8371ac | 228 | static const struct rtc_class_ops pcf8563_rtc_ops = { |
0f20b767 | 229 | .ioctl = pcf8563_rtc_ioctl, |
b5a82d62 AZ |
230 | .read_time = pcf8563_rtc_read_time, |
231 | .set_time = pcf8563_rtc_set_time, | |
232 | }; | |
233 | ||
d2653e92 JD |
234 | static int pcf8563_probe(struct i2c_client *client, |
235 | const struct i2c_device_id *id) | |
b5a82d62 | 236 | { |
cbb94502 | 237 | struct pcf8563 *pcf8563; |
b5a82d62 AZ |
238 | |
239 | int err = 0; | |
240 | ||
e5fc9cc0 | 241 | dev_dbg(&client->dev, "%s\n", __func__); |
b5a82d62 | 242 | |
e5fc9cc0 AZ |
243 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) |
244 | return -ENODEV; | |
b5a82d62 | 245 | |
e5fc9cc0 AZ |
246 | pcf8563 = kzalloc(sizeof(struct pcf8563), GFP_KERNEL); |
247 | if (!pcf8563) | |
248 | return -ENOMEM; | |
b5a82d62 | 249 | |
b5a82d62 AZ |
250 | dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); |
251 | ||
b74d2caa AZ |
252 | i2c_set_clientdata(client, pcf8563); |
253 | ||
e5fc9cc0 AZ |
254 | pcf8563->rtc = rtc_device_register(pcf8563_driver.driver.name, |
255 | &client->dev, &pcf8563_rtc_ops, THIS_MODULE); | |
b5a82d62 | 256 | |
e5fc9cc0 AZ |
257 | if (IS_ERR(pcf8563->rtc)) { |
258 | err = PTR_ERR(pcf8563->rtc); | |
259 | goto exit_kfree; | |
b5a82d62 AZ |
260 | } |
261 | ||
b5a82d62 AZ |
262 | return 0; |
263 | ||
b5a82d62 | 264 | exit_kfree: |
cbb94502 | 265 | kfree(pcf8563); |
b5a82d62 | 266 | |
b5a82d62 AZ |
267 | return err; |
268 | } | |
269 | ||
e5fc9cc0 | 270 | static int pcf8563_remove(struct i2c_client *client) |
b5a82d62 | 271 | { |
e5fc9cc0 | 272 | struct pcf8563 *pcf8563 = i2c_get_clientdata(client); |
b5a82d62 | 273 | |
e5fc9cc0 AZ |
274 | if (pcf8563->rtc) |
275 | rtc_device_unregister(pcf8563->rtc); | |
b5a82d62 | 276 | |
cbb94502 | 277 | kfree(pcf8563); |
b5a82d62 AZ |
278 | |
279 | return 0; | |
280 | } | |
281 | ||
3760f736 JD |
282 | static const struct i2c_device_id pcf8563_id[] = { |
283 | { "pcf8563", 0 }, | |
8ea9212c | 284 | { "rtc8564", 0 }, |
3760f736 JD |
285 | { } |
286 | }; | |
287 | MODULE_DEVICE_TABLE(i2c, pcf8563_id); | |
288 | ||
8dccaf06 NB |
289 | #ifdef CONFIG_OF |
290 | static const struct of_device_id pcf8563_of_match[] __devinitconst = { | |
291 | { .compatible = "nxp,pcf8563" }, | |
292 | {} | |
293 | }; | |
294 | MODULE_DEVICE_TABLE(of, pcf8563_of_match); | |
295 | #endif | |
296 | ||
e5fc9cc0 AZ |
297 | static struct i2c_driver pcf8563_driver = { |
298 | .driver = { | |
299 | .name = "rtc-pcf8563", | |
0a25bf40 | 300 | .owner = THIS_MODULE, |
8dccaf06 | 301 | .of_match_table = of_match_ptr(pcf8563_of_match), |
e5fc9cc0 AZ |
302 | }, |
303 | .probe = pcf8563_probe, | |
304 | .remove = pcf8563_remove, | |
3760f736 | 305 | .id_table = pcf8563_id, |
e5fc9cc0 AZ |
306 | }; |
307 | ||
0abc9201 | 308 | module_i2c_driver(pcf8563_driver); |
b5a82d62 AZ |
309 | |
310 | MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); | |
311 | MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver"); | |
312 | MODULE_LICENSE("GPL"); | |
313 | MODULE_VERSION(DRV_VERSION); |