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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#include <linux/slab.h>
21
22#define DRV_VERSION "0.4.3"
23
24#define PCF8563_REG_ST1 0x00 /* status */
25#define PCF8563_REG_ST2 0x01
26
27#define PCF8563_REG_SC 0x02 /* datetime */
28#define PCF8563_REG_MN 0x03
29#define PCF8563_REG_HR 0x04
30#define PCF8563_REG_DM 0x05
31#define PCF8563_REG_DW 0x06
32#define PCF8563_REG_MO 0x07
33#define PCF8563_REG_YR 0x08
34
35#define PCF8563_REG_AMN 0x09 /* alarm */
36#define PCF8563_REG_AHR 0x0A
37#define PCF8563_REG_ADM 0x0B
38#define PCF8563_REG_ADW 0x0C
39
40#define PCF8563_REG_CLKO 0x0D /* clock out */
41#define PCF8563_REG_TMRC 0x0E /* timer control */
42#define PCF8563_REG_TMR 0x0F /* timer */
43
44#define PCF8563_SC_LV 0x80 /* low voltage */
45#define PCF8563_MO_C 0x80 /* century */
46
47static struct i2c_driver pcf8563_driver;
48
49struct pcf8563 {
50 struct rtc_device *rtc;
51 /*
52 * The meaning of MO_C bit varies by the chip type.
53 * From PCF8563 datasheet: this bit is toggled when the years
54 * register overflows from 99 to 00
55 * 0 indicates the century is 20xx
56 * 1 indicates the century is 19xx
57 * From RTC8564 datasheet: this bit indicates change of
58 * century. When the year digit data overflows from 99 to 00,
59 * this bit is set. By presetting it to 0 while still in the
60 * 20th century, it will be set in year 2000, ...
61 * There seems no reliable way to know how the system use this
62 * bit. So let's do it heuristically, assuming we are live in
63 * 1970...2069.
64 */
65 int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
66};
67
68/*
69 * In the routines that deal directly with the pcf8563 hardware, we use
70 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
71 */
72static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
73{
74 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
75 unsigned char buf[13] = { PCF8563_REG_ST1 };
76
77 struct i2c_msg msgs[] = {
78 { client->addr, 0, 1, buf }, /* setup read ptr */
79 { client->addr, I2C_M_RD, 13, buf }, /* read status + date */
80 };
81
82 /* read registers */
83 if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
84 dev_err(&client->dev, "%s: read error\n", __func__);
85 return -EIO;
86 }
87
88 if (buf[PCF8563_REG_SC] & PCF8563_SC_LV)
89 dev_info(&client->dev,
90 "low voltage detected, date/time is not reliable.\n");
91
92 dev_dbg(&client->dev,
93 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
94 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
95 __func__,
96 buf[0], buf[1], buf[2], buf[3],
97 buf[4], buf[5], buf[6], buf[7],
98 buf[8]);
99
100
101 tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
102 tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
103 tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
104 tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
105 tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
106 tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
107 tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
108 if (tm->tm_year < 70)
109 tm->tm_year += 100; /* assume we are in 1970...2069 */
110 /* detect the polarity heuristically. see note above. */
111 pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
112 (tm->tm_year >= 100) : (tm->tm_year < 100);
113
114 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
115 "mday=%d, mon=%d, year=%d, wday=%d\n",
116 __func__,
117 tm->tm_sec, tm->tm_min, tm->tm_hour,
118 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
119
120 /* the clock can give out invalid datetime, but we cannot return
121 * -EINVAL otherwise hwclock will refuse to set the time on bootup.
122 */
123 if (rtc_valid_tm(tm) < 0)
124 dev_err(&client->dev, "retrieved date/time is not valid.\n");
125
126 return 0;
127}
128
129static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
130{
131 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
132 int i, err;
133 unsigned char buf[9];
134
135 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
136 "mday=%d, mon=%d, year=%d, wday=%d\n",
137 __func__,
138 tm->tm_sec, tm->tm_min, tm->tm_hour,
139 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
140
141 /* hours, minutes and seconds */
142 buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
143 buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
144 buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
145
146 buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
147
148 /* month, 1 - 12 */
149 buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
150
151 /* year and century */
152 buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
153 if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
154 buf[PCF8563_REG_MO] |= PCF8563_MO_C;
155
156 buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
157
158 /* write register's data */
159 for (i = 0; i < 7; i++) {
160 unsigned char data[2] = { PCF8563_REG_SC + i,
161 buf[PCF8563_REG_SC + i] };
162
163 err = i2c_master_send(client, data, sizeof(data));
164 if (err != sizeof(data)) {
165 dev_err(&client->dev,
166 "%s: err=%d addr=%02x, data=%02x\n",
167 __func__, err, data[0], data[1]);
168 return -EIO;
169 }
170 };
171
172 return 0;
173}
174
175static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
176{
177 return pcf8563_get_datetime(to_i2c_client(dev), tm);
178}
179
180static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
181{
182 return pcf8563_set_datetime(to_i2c_client(dev), tm);
183}
184
185static const struct rtc_class_ops pcf8563_rtc_ops = {
186 .read_time = pcf8563_rtc_read_time,
187 .set_time = pcf8563_rtc_set_time,
188};
189
190static int pcf8563_probe(struct i2c_client *client,
191 const struct i2c_device_id *id)
192{
193 struct pcf8563 *pcf8563;
194
195 int err = 0;
196
197 dev_dbg(&client->dev, "%s\n", __func__);
198
199 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
200 return -ENODEV;
201
202 pcf8563 = kzalloc(sizeof(struct pcf8563), GFP_KERNEL);
203 if (!pcf8563)
204 return -ENOMEM;
205
206 dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
207
208 i2c_set_clientdata(client, pcf8563);
209
210 pcf8563->rtc = rtc_device_register(pcf8563_driver.driver.name,
211 &client->dev, &pcf8563_rtc_ops, THIS_MODULE);
212
213 if (IS_ERR(pcf8563->rtc)) {
214 err = PTR_ERR(pcf8563->rtc);
215 goto exit_kfree;
216 }
217
218 return 0;
219
220exit_kfree:
221 kfree(pcf8563);
222
223 return err;
224}
225
226static int pcf8563_remove(struct i2c_client *client)
227{
228 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
229
230 if (pcf8563->rtc)
231 rtc_device_unregister(pcf8563->rtc);
232
233 kfree(pcf8563);
234
235 return 0;
236}
237
238static const struct i2c_device_id pcf8563_id[] = {
239 { "pcf8563", 0 },
240 { "rtc8564", 0 },
241 { }
242};
243MODULE_DEVICE_TABLE(i2c, pcf8563_id);
244
245static struct i2c_driver pcf8563_driver = {
246 .driver = {
247 .name = "rtc-pcf8563",
248 },
249 .probe = pcf8563_probe,
250 .remove = pcf8563_remove,
251 .id_table = pcf8563_id,
252};
253
254static int __init pcf8563_init(void)
255{
256 return i2c_add_driver(&pcf8563_driver);
257}
258
259static void __exit pcf8563_exit(void)
260{
261 i2c_del_driver(&pcf8563_driver);
262}
263
264MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
265MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
266MODULE_LICENSE("GPL");
267MODULE_VERSION(DRV_VERSION);
268
269module_init(pcf8563_init);
270module_exit(pcf8563_exit);
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#include <linux/slab.h>
21#include <linux/module.h>
22
23#define DRV_VERSION "0.4.3"
24
25#define PCF8563_REG_ST1 0x00 /* status */
26#define PCF8563_REG_ST2 0x01
27
28#define PCF8563_REG_SC 0x02 /* datetime */
29#define PCF8563_REG_MN 0x03
30#define PCF8563_REG_HR 0x04
31#define PCF8563_REG_DM 0x05
32#define PCF8563_REG_DW 0x06
33#define PCF8563_REG_MO 0x07
34#define PCF8563_REG_YR 0x08
35
36#define PCF8563_REG_AMN 0x09 /* alarm */
37#define PCF8563_REG_AHR 0x0A
38#define PCF8563_REG_ADM 0x0B
39#define PCF8563_REG_ADW 0x0C
40
41#define PCF8563_REG_CLKO 0x0D /* clock out */
42#define PCF8563_REG_TMRC 0x0E /* timer control */
43#define PCF8563_REG_TMR 0x0F /* timer */
44
45#define PCF8563_SC_LV 0x80 /* low voltage */
46#define PCF8563_MO_C 0x80 /* century */
47
48static struct i2c_driver pcf8563_driver;
49
50struct pcf8563 {
51 struct rtc_device *rtc;
52 /*
53 * The meaning of MO_C bit varies by the chip type.
54 * From PCF8563 datasheet: this bit is toggled when the years
55 * register overflows from 99 to 00
56 * 0 indicates the century is 20xx
57 * 1 indicates the century is 19xx
58 * From RTC8564 datasheet: this bit indicates change of
59 * century. When the year digit data overflows from 99 to 00,
60 * this bit is set. By presetting it to 0 while still in the
61 * 20th century, it will be set in year 2000, ...
62 * There seems no reliable way to know how the system use this
63 * bit. So let's do it heuristically, assuming we are live in
64 * 1970...2069.
65 */
66 int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
67 int voltage_low; /* incicates if a low_voltage was detected */
68};
69
70/*
71 * In the routines that deal directly with the pcf8563 hardware, we use
72 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
73 */
74static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
75{
76 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
77 unsigned char buf[13] = { PCF8563_REG_ST1 };
78
79 struct i2c_msg msgs[] = {
80 { client->addr, 0, 1, buf }, /* setup read ptr */
81 { client->addr, I2C_M_RD, 13, buf }, /* read status + date */
82 };
83
84 /* read registers */
85 if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
86 dev_err(&client->dev, "%s: read error\n", __func__);
87 return -EIO;
88 }
89
90 if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
91 pcf8563->voltage_low = 1;
92 dev_info(&client->dev,
93 "low voltage detected, date/time is not reliable.\n");
94 }
95
96 dev_dbg(&client->dev,
97 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
98 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
99 __func__,
100 buf[0], buf[1], buf[2], buf[3],
101 buf[4], buf[5], buf[6], buf[7],
102 buf[8]);
103
104
105 tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
106 tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
107 tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
108 tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
109 tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
110 tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
111 tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
112 if (tm->tm_year < 70)
113 tm->tm_year += 100; /* assume we are in 1970...2069 */
114 /* detect the polarity heuristically. see note above. */
115 pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
116 (tm->tm_year >= 100) : (tm->tm_year < 100);
117
118 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
119 "mday=%d, mon=%d, year=%d, wday=%d\n",
120 __func__,
121 tm->tm_sec, tm->tm_min, tm->tm_hour,
122 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
123
124 /* the clock can give out invalid datetime, but we cannot return
125 * -EINVAL otherwise hwclock will refuse to set the time on bootup.
126 */
127 if (rtc_valid_tm(tm) < 0)
128 dev_err(&client->dev, "retrieved date/time is not valid.\n");
129
130 return 0;
131}
132
133static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
134{
135 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
136 int i, err;
137 unsigned char buf[9];
138
139 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
140 "mday=%d, mon=%d, year=%d, wday=%d\n",
141 __func__,
142 tm->tm_sec, tm->tm_min, tm->tm_hour,
143 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
144
145 /* hours, minutes and seconds */
146 buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
147 buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
148 buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
149
150 buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
151
152 /* month, 1 - 12 */
153 buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
154
155 /* year and century */
156 buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
157 if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
158 buf[PCF8563_REG_MO] |= PCF8563_MO_C;
159
160 buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
161
162 /* write register's data */
163 for (i = 0; i < 7; i++) {
164 unsigned char data[2] = { PCF8563_REG_SC + i,
165 buf[PCF8563_REG_SC + i] };
166
167 err = i2c_master_send(client, data, sizeof(data));
168 if (err != sizeof(data)) {
169 dev_err(&client->dev,
170 "%s: err=%d addr=%02x, data=%02x\n",
171 __func__, err, data[0], data[1]);
172 return -EIO;
173 }
174 };
175
176 return 0;
177}
178
179#ifdef CONFIG_RTC_INTF_DEV
180static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
181{
182 struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
183 struct rtc_time tm;
184
185 switch (cmd) {
186 case RTC_VL_READ:
187 if (pcf8563->voltage_low)
188 dev_info(dev, "low voltage detected, date/time is not reliable.\n");
189
190 if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
191 sizeof(int)))
192 return -EFAULT;
193 return 0;
194 case RTC_VL_CLR:
195 /*
196 * Clear the VL bit in the seconds register in case
197 * the time has not been set already (which would
198 * have cleared it). This does not really matter
199 * because of the cached voltage_low value but do it
200 * anyway for consistency.
201 */
202 if (pcf8563_get_datetime(to_i2c_client(dev), &tm))
203 pcf8563_set_datetime(to_i2c_client(dev), &tm);
204
205 /* Clear the cached value. */
206 pcf8563->voltage_low = 0;
207
208 return 0;
209 default:
210 return -ENOIOCTLCMD;
211 }
212}
213#else
214#define pcf8563_rtc_ioctl NULL
215#endif
216
217static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
218{
219 return pcf8563_get_datetime(to_i2c_client(dev), tm);
220}
221
222static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
223{
224 return pcf8563_set_datetime(to_i2c_client(dev), tm);
225}
226
227static const struct rtc_class_ops pcf8563_rtc_ops = {
228 .ioctl = pcf8563_rtc_ioctl,
229 .read_time = pcf8563_rtc_read_time,
230 .set_time = pcf8563_rtc_set_time,
231};
232
233static int pcf8563_probe(struct i2c_client *client,
234 const struct i2c_device_id *id)
235{
236 struct pcf8563 *pcf8563;
237
238 int err = 0;
239
240 dev_dbg(&client->dev, "%s\n", __func__);
241
242 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
243 return -ENODEV;
244
245 pcf8563 = kzalloc(sizeof(struct pcf8563), GFP_KERNEL);
246 if (!pcf8563)
247 return -ENOMEM;
248
249 dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
250
251 i2c_set_clientdata(client, pcf8563);
252
253 pcf8563->rtc = rtc_device_register(pcf8563_driver.driver.name,
254 &client->dev, &pcf8563_rtc_ops, THIS_MODULE);
255
256 if (IS_ERR(pcf8563->rtc)) {
257 err = PTR_ERR(pcf8563->rtc);
258 goto exit_kfree;
259 }
260
261 return 0;
262
263exit_kfree:
264 kfree(pcf8563);
265
266 return err;
267}
268
269static int pcf8563_remove(struct i2c_client *client)
270{
271 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
272
273 if (pcf8563->rtc)
274 rtc_device_unregister(pcf8563->rtc);
275
276 kfree(pcf8563);
277
278 return 0;
279}
280
281static const struct i2c_device_id pcf8563_id[] = {
282 { "pcf8563", 0 },
283 { "rtc8564", 0 },
284 { }
285};
286MODULE_DEVICE_TABLE(i2c, pcf8563_id);
287
288static struct i2c_driver pcf8563_driver = {
289 .driver = {
290 .name = "rtc-pcf8563",
291 },
292 .probe = pcf8563_probe,
293 .remove = pcf8563_remove,
294 .id_table = pcf8563_id,
295};
296
297module_i2c_driver(pcf8563_driver);
298
299MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
300MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
301MODULE_LICENSE("GPL");
302MODULE_VERSION(DRV_VERSION);