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Alessandro Zummob5a82d62006-03-27 01:16:44 -08001/*
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 */
Jean Delvare922539a2008-01-27 18:14:47 +010028static const unsigned short normal_i2c[] = { I2C_CLIENT_END };
Alessandro Zummob5a82d62006-03-27 01:16:44 -080029
30/* Module parameters */
31I2C_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
Atsushi Nemotocbb94502007-02-08 14:20:24 -080056struct 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
Alessandro Zummob5a82d62006-03-27 01:16:44 -080075static int pcf8563_probe(struct i2c_adapter *adapter, int address, int kind);
76static 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 */
82static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
83{
Atsushi Nemotocbb94502007-02-08 14:20:24 -080084 struct pcf8563 *pcf8563 = container_of(client, struct pcf8563, client);
Alessandro Zummob5a82d62006-03-27 01:16:44 -080085 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 */
Atsushi Nemotocbb94502007-02-08 14:20:24 -0800117 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);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800123
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
139static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
140{
Atsushi Nemotocbb94502007-02-08 14:20:24 -0800141 struct pcf8563 *pcf8563 = container_of(client, struct pcf8563, client);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800142 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);
Atsushi Nemotocbb94502007-02-08 14:20:24 -0800163 if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800164 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
185struct pcf8563_limit
186{
187 unsigned char reg;
188 unsigned char mask;
189 unsigned char min;
190 unsigned char max;
191};
192
193static 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)) {
David Brownella14e1892006-12-10 02:19:02 -0800220 dev_err(&client->dev,
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800221 "%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) {
David Brownella14e1892006-12-10 02:19:02 -0800231 dev_dbg(&client->dev,
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800232 "%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
245static 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
250static 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
David Brownellff8371a2006-09-30 23:28:17 -0700255static const struct rtc_class_ops pcf8563_rtc_ops = {
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800256 .read_time = pcf8563_rtc_read_time,
257 .set_time = pcf8563_rtc_set_time,
258};
259
260static int pcf8563_attach(struct i2c_adapter *adapter)
261{
262 return i2c_probe(adapter, &addr_data, pcf8563_probe);
263}
264
265static 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
274static int pcf8563_probe(struct i2c_adapter *adapter, int address, int kind)
275{
Atsushi Nemotocbb94502007-02-08 14:20:24 -0800276 struct pcf8563 *pcf8563;
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800277 struct i2c_client *client;
278 struct rtc_device *rtc;
279
280 int err = 0;
281
Jean Delvare5dd3ffa2007-02-13 22:09:04 +0100282 dev_dbg(&adapter->dev, "%s\n", __FUNCTION__);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800283
284 if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
285 err = -ENODEV;
286 goto exit;
287 }
288
Atsushi Nemotocbb94502007-02-08 14:20:24 -0800289 if (!(pcf8563 = kzalloc(sizeof(struct pcf8563), GFP_KERNEL))) {
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800290 err = -ENOMEM;
291 goto exit;
292 }
293
Atsushi Nemotocbb94502007-02-08 14:20:24 -0800294 client = &pcf8563->client;
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800295 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);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800320 goto exit_detach;
321 }
322
323 i2c_set_clientdata(client, rtc);
324
325 return 0;
326
327exit_detach:
328 i2c_detach_client(client);
329
330exit_kfree:
Atsushi Nemotocbb94502007-02-08 14:20:24 -0800331 kfree(pcf8563);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800332
333exit:
334 return err;
335}
336
337static int pcf8563_detach(struct i2c_client *client)
338{
Atsushi Nemotocbb94502007-02-08 14:20:24 -0800339 struct pcf8563 *pcf8563 = container_of(client, struct pcf8563, client);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800340 int err;
341 struct rtc_device *rtc = i2c_get_clientdata(client);
342
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800343 if (rtc)
344 rtc_device_unregister(rtc);
345
346 if ((err = i2c_detach_client(client)))
347 return err;
348
Atsushi Nemotocbb94502007-02-08 14:20:24 -0800349 kfree(pcf8563);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800350
351 return 0;
352}
353
354static int __init pcf8563_init(void)
355{
356 return i2c_add_driver(&pcf8563_driver);
357}
358
359static void __exit pcf8563_exit(void)
360{
361 i2c_del_driver(&pcf8563_driver);
362}
363
364MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
365MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
366MODULE_LICENSE("GPL");
367MODULE_VERSION(DRV_VERSION);
368
369module_init(pcf8563_init);
370module_exit(pcf8563_exit);