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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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090020#include <linux/slab.h>
Paul Gortmaker21138522011-05-27 09:57:25 -040021#include <linux/module.h>
Nick Bowler8dccaf02012-07-30 14:41:59 -070022#include <linux/of.h>
Alessandro Zummob5a82d62006-03-27 01:16:44 -080023
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -070024#define DRV_VERSION "0.4.3"
Alessandro Zummob5a82d62006-03-27 01:16:44 -080025
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
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -070049static struct i2c_driver pcf8563_driver;
50
Atsushi Nemotocbb94502007-02-08 14:20:24 -080051struct pcf8563 {
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -070052 struct rtc_device *rtc;
Atsushi Nemotocbb94502007-02-08 14:20:24 -080053 /*
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 */
Alexander Stein0f20b762012-05-29 15:07:36 -070068 int voltage_low; /* incicates if a low_voltage was detected */
Atsushi Nemotocbb94502007-02-08 14:20:24 -080069};
70
Alessandro Zummob5a82d62006-03-27 01:16:44 -080071/*
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 */
75static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
76{
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -070077 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
Alessandro Zummob5a82d62006-03-27 01:16:44 -080078 unsigned char buf[13] = { PCF8563_REG_ST1 };
79
80 struct i2c_msg msgs[] = {
Shubhrajyoti D755e4a42012-10-04 17:14:25 -070081 {/* setup read ptr */
82 .addr = client->addr,
83 .len = 1,
84 .buf = buf
85 },
86 {/* read status + date */
87 .addr = client->addr,
88 .flags = I2C_M_RD,
89 .len = 13,
90 .buf = buf
91 },
Alessandro Zummob5a82d62006-03-27 01:16:44 -080092 };
93
94 /* read registers */
95 if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
Harvey Harrison2a4e2b82008-04-28 02:12:00 -070096 dev_err(&client->dev, "%s: read error\n", __func__);
Alessandro Zummob5a82d62006-03-27 01:16:44 -080097 return -EIO;
98 }
99
Alexander Stein0f20b762012-05-29 15:07:36 -0700100 if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
101 pcf8563->voltage_low = 1;
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800102 dev_info(&client->dev,
103 "low voltage detected, date/time is not reliable.\n");
Alexander Stein0f20b762012-05-29 15:07:36 -0700104 }
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800105
106 dev_dbg(&client->dev,
107 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
108 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
Harvey Harrison2a4e2b82008-04-28 02:12:00 -0700109 __func__,
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800110 buf[0], buf[1], buf[2], buf[3],
111 buf[4], buf[5], buf[6], buf[7],
112 buf[8]);
113
114
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700115 tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
116 tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
117 tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
118 tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800119 tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700120 tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
121 tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
Atsushi Nemotocbb94502007-02-08 14:20:24 -0800122 if (tm->tm_year < 70)
123 tm->tm_year += 100; /* assume we are in 1970...2069 */
124 /* detect the polarity heuristically. see note above. */
125 pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
126 (tm->tm_year >= 100) : (tm->tm_year < 100);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800127
128 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
129 "mday=%d, mon=%d, year=%d, wday=%d\n",
Harvey Harrison2a4e2b82008-04-28 02:12:00 -0700130 __func__,
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800131 tm->tm_sec, tm->tm_min, tm->tm_hour,
132 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
133
134 /* the clock can give out invalid datetime, but we cannot return
135 * -EINVAL otherwise hwclock will refuse to set the time on bootup.
136 */
137 if (rtc_valid_tm(tm) < 0)
138 dev_err(&client->dev, "retrieved date/time is not valid.\n");
139
140 return 0;
141}
142
143static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
144{
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700145 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800146 int i, err;
147 unsigned char buf[9];
148
149 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
150 "mday=%d, mon=%d, year=%d, wday=%d\n",
Harvey Harrison2a4e2b82008-04-28 02:12:00 -0700151 __func__,
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800152 tm->tm_sec, tm->tm_min, tm->tm_hour,
153 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
154
155 /* hours, minutes and seconds */
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700156 buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
157 buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
158 buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800159
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700160 buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800161
162 /* month, 1 - 12 */
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700163 buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800164
165 /* year and century */
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700166 buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
Atsushi Nemotocbb94502007-02-08 14:20:24 -0800167 if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800168 buf[PCF8563_REG_MO] |= PCF8563_MO_C;
169
170 buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
171
172 /* write register's data */
173 for (i = 0; i < 7; i++) {
174 unsigned char data[2] = { PCF8563_REG_SC + i,
175 buf[PCF8563_REG_SC + i] };
176
177 err = i2c_master_send(client, data, sizeof(data));
178 if (err != sizeof(data)) {
179 dev_err(&client->dev,
180 "%s: err=%d addr=%02x, data=%02x\n",
Harvey Harrison2a4e2b82008-04-28 02:12:00 -0700181 __func__, err, data[0], data[1]);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800182 return -EIO;
183 }
Peter Senna Tschudin0b7e0392013-02-21 16:44:30 -0800184 }
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800185
186 return 0;
187}
188
Alexander Stein0f20b762012-05-29 15:07:36 -0700189#ifdef CONFIG_RTC_INTF_DEV
190static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
191{
192 struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
193 struct rtc_time tm;
194
195 switch (cmd) {
196 case RTC_VL_READ:
197 if (pcf8563->voltage_low)
198 dev_info(dev, "low voltage detected, date/time is not reliable.\n");
199
200 if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
201 sizeof(int)))
202 return -EFAULT;
203 return 0;
204 case RTC_VL_CLR:
205 /*
206 * Clear the VL bit in the seconds register in case
207 * the time has not been set already (which would
208 * have cleared it). This does not really matter
209 * because of the cached voltage_low value but do it
210 * anyway for consistency.
211 */
212 if (pcf8563_get_datetime(to_i2c_client(dev), &tm))
213 pcf8563_set_datetime(to_i2c_client(dev), &tm);
214
215 /* Clear the cached value. */
216 pcf8563->voltage_low = 0;
217
218 return 0;
219 default:
220 return -ENOIOCTLCMD;
221 }
222}
223#else
224#define pcf8563_rtc_ioctl NULL
225#endif
226
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800227static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
228{
229 return pcf8563_get_datetime(to_i2c_client(dev), tm);
230}
231
232static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
233{
234 return pcf8563_set_datetime(to_i2c_client(dev), tm);
235}
236
David Brownellff8371a2006-09-30 23:28:17 -0700237static const struct rtc_class_ops pcf8563_rtc_ops = {
Alexander Stein0f20b762012-05-29 15:07:36 -0700238 .ioctl = pcf8563_rtc_ioctl,
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800239 .read_time = pcf8563_rtc_read_time,
240 .set_time = pcf8563_rtc_set_time,
241};
242
Jean Delvared2653e92008-04-29 23:11:39 +0200243static int pcf8563_probe(struct i2c_client *client,
244 const struct i2c_device_id *id)
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800245{
Atsushi Nemotocbb94502007-02-08 14:20:24 -0800246 struct pcf8563 *pcf8563;
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800247
248 int err = 0;
249
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700250 dev_dbg(&client->dev, "%s\n", __func__);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800251
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700252 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
253 return -ENODEV;
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800254
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700255 pcf8563 = kzalloc(sizeof(struct pcf8563), GFP_KERNEL);
256 if (!pcf8563)
257 return -ENOMEM;
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800258
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800259 dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
260
Alessandro Zummob74d2ca2009-12-15 16:45:53 -0800261 i2c_set_clientdata(client, pcf8563);
262
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700263 pcf8563->rtc = rtc_device_register(pcf8563_driver.driver.name,
264 &client->dev, &pcf8563_rtc_ops, THIS_MODULE);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800265
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700266 if (IS_ERR(pcf8563->rtc)) {
267 err = PTR_ERR(pcf8563->rtc);
268 goto exit_kfree;
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800269 }
270
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800271 return 0;
272
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800273exit_kfree:
Atsushi Nemotocbb94502007-02-08 14:20:24 -0800274 kfree(pcf8563);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800275
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800276 return err;
277}
278
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700279static int pcf8563_remove(struct i2c_client *client)
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800280{
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700281 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800282
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700283 if (pcf8563->rtc)
284 rtc_device_unregister(pcf8563->rtc);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800285
Atsushi Nemotocbb94502007-02-08 14:20:24 -0800286 kfree(pcf8563);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800287
288 return 0;
289}
290
Jean Delvare3760f732008-04-29 23:11:40 +0200291static const struct i2c_device_id pcf8563_id[] = {
292 { "pcf8563", 0 },
Jon Smirl8ea92122008-07-12 13:47:56 -0700293 { "rtc8564", 0 },
Jean Delvare3760f732008-04-29 23:11:40 +0200294 { }
295};
296MODULE_DEVICE_TABLE(i2c, pcf8563_id);
297
Nick Bowler8dccaf02012-07-30 14:41:59 -0700298#ifdef CONFIG_OF
Greg Kroah-Hartman5a167f42012-12-21 13:09:38 -0800299static const struct of_device_id pcf8563_of_match[] = {
Nick Bowler8dccaf02012-07-30 14:41:59 -0700300 { .compatible = "nxp,pcf8563" },
301 {}
302};
303MODULE_DEVICE_TABLE(of, pcf8563_of_match);
304#endif
305
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700306static struct i2c_driver pcf8563_driver = {
307 .driver = {
308 .name = "rtc-pcf8563",
Nick Bowler0a25bf42012-07-30 14:41:57 -0700309 .owner = THIS_MODULE,
Nick Bowler8dccaf02012-07-30 14:41:59 -0700310 .of_match_table = of_match_ptr(pcf8563_of_match),
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700311 },
312 .probe = pcf8563_probe,
313 .remove = pcf8563_remove,
Jean Delvare3760f732008-04-29 23:11:40 +0200314 .id_table = pcf8563_id,
Alessandro Zummoe5fc9cc2008-04-28 02:11:54 -0700315};
316
Axel Lin0abc9202012-03-23 15:02:31 -0700317module_i2c_driver(pcf8563_driver);
Alessandro Zummob5a82d62006-03-27 01:16:44 -0800318
319MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
320MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
321MODULE_LICENSE("GPL");
322MODULE_VERSION(DRV_VERSION);