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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
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -070021#define DRV_VERSION "0.4.3"
Alessandro Zummob5a82d62006-03-27 01:16:44 -080022
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
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -070046static struct i2c_driver pcf8563_driver;
47
Atsushi Nemotocbb94502007-02-08 14:20:24 -080048struct pcf8563 {
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -070049 struct rtc_device *rtc;
Atsushi Nemotocbb94502007-02-08 14:20:24 -080050 /*
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
Alessandro Zummob5a82d62006-03-27 01:16:44 -080067/*
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 */
71static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
72{
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -070073 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
Alessandro Zummob5a82d62006-03-27 01:16:44 -080074 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) {
Harvey Harrison2a4e2b82008-04-28 02:12:00 -070083 dev_err(&client->dev, "%s: read error\n", __func__);
Alessandro Zummob5a82d62006-03-27 01:16:44 -080084 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",
Harvey Harrison2a4e2b82008-04-28 02:12:00 -070094 __func__,
Alessandro Zummob5a82d62006-03-27 01:16:44 -080095 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 */
Atsushi Nemotocbb94502007-02-08 14:20:24 -0800106 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);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800112
113 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
114 "mday=%d, mon=%d, year=%d, wday=%d\n",
Harvey Harrison2a4e2b82008-04-28 02:12:00 -0700115 __func__,
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800116 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
128static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
129{
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700130 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800131 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",
Harvey Harrison2a4e2b82008-04-28 02:12:00 -0700136 __func__,
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800137 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);
Atsushi Nemotocbb94502007-02-08 14:20:24 -0800152 if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800153 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",
Harvey Harrison2a4e2b82008-04-28 02:12:00 -0700166 __func__, err, data[0], data[1]);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800167 return -EIO;
168 }
169 };
170
171 return 0;
172}
173
174struct pcf8563_limit
175{
176 unsigned char reg;
177 unsigned char mask;
178 unsigned char min;
179 unsigned char max;
180};
181
182static 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)) {
David Brownella14e1892006-12-10 02:19:02 -0800209 dev_err(&client->dev,
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800210 "%s: could not read register 0x%02X\n",
Harvey Harrison2a4e2b82008-04-28 02:12:00 -0700211 __func__, pattern[i].reg);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800212
213 return -EIO;
214 }
215
216 value = BCD2BIN(buf & pattern[i].mask);
217
218 if (value > pattern[i].max ||
219 value < pattern[i].min) {
David Brownella14e1892006-12-10 02:19:02 -0800220 dev_dbg(&client->dev,
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800221 "%s: pattern=%d, reg=%x, mask=0x%02x, min=%d, "
222 "max=%d, value=%d, raw=0x%02X\n",
Harvey Harrison2a4e2b82008-04-28 02:12:00 -0700223 __func__, i, pattern[i].reg, pattern[i].mask,
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800224 pattern[i].min, pattern[i].max,
225 value, buf);
226
227 return -ENODEV;
228 }
229 }
230
231 return 0;
232}
233
234static 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
239static 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
David Brownellff8371a2006-09-30 23:28:17 -0700244static const struct rtc_class_ops pcf8563_rtc_ops = {
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800245 .read_time = pcf8563_rtc_read_time,
246 .set_time = pcf8563_rtc_set_time,
247};
248
Jean Delvared2653e92008-04-29 23:11:39 +0200249static int pcf8563_probe(struct i2c_client *client,
250 const struct i2c_device_id *id)
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800251{
Atsushi Nemotocbb94502007-02-08 14:20:24 -0800252 struct pcf8563 *pcf8563;
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800253
254 int err = 0;
255
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700256 dev_dbg(&client->dev, "%s\n", __func__);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800257
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700258 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
259 return -ENODEV;
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800260
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700261 pcf8563 = kzalloc(sizeof(struct pcf8563), GFP_KERNEL);
262 if (!pcf8563)
263 return -ENOMEM;
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800264
265 /* Verify the chip is really an PCF8563 */
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700266 if (pcf8563_validate_client(client) < 0) {
267 err = -ENODEV;
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800268 goto exit_kfree;
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700269 }
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800270
271 dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
272
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700273 pcf8563->rtc = rtc_device_register(pcf8563_driver.driver.name,
274 &client->dev, &pcf8563_rtc_ops, THIS_MODULE);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800275
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700276 if (IS_ERR(pcf8563->rtc)) {
277 err = PTR_ERR(pcf8563->rtc);
278 goto exit_kfree;
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800279 }
280
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700281 i2c_set_clientdata(client, pcf8563);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800282
283 return 0;
284
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800285exit_kfree:
Atsushi Nemotocbb94502007-02-08 14:20:24 -0800286 kfree(pcf8563);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800287
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800288 return err;
289}
290
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700291static int pcf8563_remove(struct i2c_client *client)
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800292{
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700293 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800294
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700295 if (pcf8563->rtc)
296 rtc_device_unregister(pcf8563->rtc);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800297
Atsushi Nemotocbb94502007-02-08 14:20:24 -0800298 kfree(pcf8563);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800299
300 return 0;
301}
302
Jean Delvare3760f732008-04-29 23:11:40 +0200303static const struct i2c_device_id pcf8563_id[] = {
304 { "pcf8563", 0 },
305 { }
306};
307MODULE_DEVICE_TABLE(i2c, pcf8563_id);
308
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700309static struct i2c_driver pcf8563_driver = {
310 .driver = {
311 .name = "rtc-pcf8563",
312 },
313 .probe = pcf8563_probe,
314 .remove = pcf8563_remove,
Jean Delvare3760f732008-04-29 23:11:40 +0200315 .id_table = pcf8563_id,
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700316};
317
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800318static int __init pcf8563_init(void)
319{
320 return i2c_add_driver(&pcf8563_driver);
321}
322
323static void __exit pcf8563_exit(void)
324{
325 i2c_del_driver(&pcf8563_driver);
326}
327
328MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
329MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
330MODULE_LICENSE("GPL");
331MODULE_VERSION(DRV_VERSION);
332
333module_init(pcf8563_init);
334module_exit(pcf8563_exit);