Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6-block.git] / drivers / rtc / rtc-pcf2127.c
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1/*
2 * An I2C driver for the NXP PCF2127 RTC
3 * Copyright 2013 Til-Technologies
4 *
5 * Author: Renaud Cerrato <r.cerrato@til-technologies.fr>
6 *
7 * based on the other drivers in this same directory.
8 *
9 * http://www.nxp.com/documents/data_sheet/PCF2127AT.pdf
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 */
15
16#include <linux/i2c.h>
17#include <linux/bcd.h>
18#include <linux/rtc.h>
19#include <linux/slab.h>
20#include <linux/module.h>
21#include <linux/of.h>
22
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23#define PCF2127_REG_CTRL1 (0x00) /* Control Register 1 */
24#define PCF2127_REG_CTRL2 (0x01) /* Control Register 2 */
f97cfddc 25
18cb6368 26#define PCF2127_REG_CTRL3 (0x02) /* Control Register 3 */
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27#define PCF2127_REG_CTRL3_BLF BIT(2)
28
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29#define PCF2127_REG_SC (0x03) /* datetime */
30#define PCF2127_REG_MN (0x04)
31#define PCF2127_REG_HR (0x05)
32#define PCF2127_REG_DM (0x06)
33#define PCF2127_REG_DW (0x07)
34#define PCF2127_REG_MO (0x08)
35#define PCF2127_REG_YR (0x09)
36
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37#define PCF2127_OSF BIT(7) /* Oscillator Fail flag */
38
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39static struct i2c_driver pcf2127_driver;
40
41struct pcf2127 {
42 struct rtc_device *rtc;
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43};
44
45/*
46 * In the routines that deal directly with the pcf2127 hardware, we use
47 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
48 */
49static int pcf2127_get_datetime(struct i2c_client *client, struct rtc_time *tm)
50{
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51 unsigned char buf[10] = { PCF2127_REG_CTRL1 };
52
53 /* read registers */
54 if (i2c_master_send(client, buf, 1) != 1 ||
55 i2c_master_recv(client, buf, sizeof(buf)) != sizeof(buf)) {
56 dev_err(&client->dev, "%s: read error\n", __func__);
57 return -EIO;
58 }
59
f97cfddc 60 if (buf[PCF2127_REG_CTRL3] & PCF2127_REG_CTRL3_BLF)
18cb6368 61 dev_info(&client->dev,
653ebd75 62 "low voltage detected, check/replace RTC battery.\n");
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63
64 if (buf[PCF2127_REG_SC] & PCF2127_OSF) {
65 /*
66 * no need clear the flag here,
67 * it will be cleared once the new date is saved
68 */
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69 dev_warn(&client->dev,
70 "oscillator stop detected, date/time is not reliable\n");
71 return -EINVAL;
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72 }
73
74 dev_dbg(&client->dev,
75 "%s: raw data is cr1=%02x, cr2=%02x, cr3=%02x, "
76 "sec=%02x, min=%02x, hr=%02x, "
77 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
78 __func__,
79 buf[0], buf[1], buf[2],
80 buf[3], buf[4], buf[5],
81 buf[6], buf[7], buf[8], buf[9]);
82
83
84 tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F);
85 tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F);
86 tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F); /* rtc hr 0-23 */
87 tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F);
88 tm->tm_wday = buf[PCF2127_REG_DW] & 0x07;
89 tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
90 tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]);
91 if (tm->tm_year < 70)
92 tm->tm_year += 100; /* assume we are in 1970...2069 */
93
94 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
95 "mday=%d, mon=%d, year=%d, wday=%d\n",
96 __func__,
97 tm->tm_sec, tm->tm_min, tm->tm_hour,
98 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
99
821f51c4 100 return rtc_valid_tm(tm);
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101}
102
103static int pcf2127_set_datetime(struct i2c_client *client, struct rtc_time *tm)
104{
105 unsigned char buf[8];
106 int i = 0, err;
107
108 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
109 "mday=%d, mon=%d, year=%d, wday=%d\n",
110 __func__,
111 tm->tm_sec, tm->tm_min, tm->tm_hour,
112 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
113
114 /* start register address */
115 buf[i++] = PCF2127_REG_SC;
116
117 /* hours, minutes and seconds */
653ebd75 118 buf[i++] = bin2bcd(tm->tm_sec); /* this will also clear OSF flag */
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119 buf[i++] = bin2bcd(tm->tm_min);
120 buf[i++] = bin2bcd(tm->tm_hour);
121 buf[i++] = bin2bcd(tm->tm_mday);
122 buf[i++] = tm->tm_wday & 0x07;
123
124 /* month, 1 - 12 */
125 buf[i++] = bin2bcd(tm->tm_mon + 1);
126
127 /* year */
128 buf[i++] = bin2bcd(tm->tm_year % 100);
129
130 /* write register's data */
131 err = i2c_master_send(client, buf, i);
132 if (err != i) {
133 dev_err(&client->dev,
134 "%s: err=%d", __func__, err);
135 return -EIO;
136 }
137
138 return 0;
139}
140
141#ifdef CONFIG_RTC_INTF_DEV
142static int pcf2127_rtc_ioctl(struct device *dev,
143 unsigned int cmd, unsigned long arg)
144{
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145 struct i2c_client *client = to_i2c_client(dev);
146 unsigned char buf = PCF2127_REG_CTRL3;
147 int touser;
148 int ret;
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149
150 switch (cmd) {
151 case RTC_VL_READ:
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152 ret = i2c_master_send(client, &buf, 1);
153 if (!ret)
154 ret = -EIO;
155 if (ret < 0)
156 return ret;
157
158 ret = i2c_master_recv(client, &buf, 1);
159 if (!ret)
160 ret = -EIO;
161 if (ret < 0)
162 return ret;
163
164 touser = buf & PCF2127_REG_CTRL3_BLF ? 1 : 0;
18cb6368 165
f97cfddc 166 if (copy_to_user((void __user *)arg, &touser, sizeof(int)))
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167 return -EFAULT;
168 return 0;
169 default:
170 return -ENOIOCTLCMD;
171 }
172}
173#else
174#define pcf2127_rtc_ioctl NULL
175#endif
176
177static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm)
178{
179 return pcf2127_get_datetime(to_i2c_client(dev), tm);
180}
181
182static int pcf2127_rtc_set_time(struct device *dev, struct rtc_time *tm)
183{
184 return pcf2127_set_datetime(to_i2c_client(dev), tm);
185}
186
187static const struct rtc_class_ops pcf2127_rtc_ops = {
188 .ioctl = pcf2127_rtc_ioctl,
189 .read_time = pcf2127_rtc_read_time,
190 .set_time = pcf2127_rtc_set_time,
191};
192
193static int pcf2127_probe(struct i2c_client *client,
194 const struct i2c_device_id *id)
195{
196 struct pcf2127 *pcf2127;
197
198 dev_dbg(&client->dev, "%s\n", __func__);
199
200 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
201 return -ENODEV;
202
203 pcf2127 = devm_kzalloc(&client->dev, sizeof(struct pcf2127),
204 GFP_KERNEL);
205 if (!pcf2127)
206 return -ENOMEM;
207
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208 i2c_set_clientdata(client, pcf2127);
209
210 pcf2127->rtc = devm_rtc_device_register(&client->dev,
211 pcf2127_driver.driver.name,
212 &pcf2127_rtc_ops, THIS_MODULE);
213
7ab26cd1 214 return PTR_ERR_OR_ZERO(pcf2127->rtc);
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215}
216
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217static const struct i2c_device_id pcf2127_id[] = {
218 { "pcf2127", 0 },
219 { }
220};
221MODULE_DEVICE_TABLE(i2c, pcf2127_id);
222
223#ifdef CONFIG_OF
224static const struct of_device_id pcf2127_of_match[] = {
225 { .compatible = "nxp,pcf2127" },
226 {}
227};
228MODULE_DEVICE_TABLE(of, pcf2127_of_match);
229#endif
230
231static struct i2c_driver pcf2127_driver = {
232 .driver = {
233 .name = "rtc-pcf2127",
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234 .of_match_table = of_match_ptr(pcf2127_of_match),
235 },
236 .probe = pcf2127_probe,
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237 .id_table = pcf2127_id,
238};
239
240module_i2c_driver(pcf2127_driver);
241
242MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>");
243MODULE_DESCRIPTION("NXP PCF2127 RTC driver");
4d8318bc 244MODULE_LICENSE("GPL v2");