Version:  2.0.40 2.2.26 2.4.37 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4

Linux/drivers/rtc/rtc-pcf2127.c

  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 
 23 #define PCF2127_REG_CTRL1       (0x00)  /* Control Register 1 */
 24 #define PCF2127_REG_CTRL2       (0x01)  /* Control Register 2 */
 25 
 26 #define PCF2127_REG_CTRL3       (0x02)  /* Control Register 3 */
 27 #define PCF2127_REG_CTRL3_BLF           BIT(2)
 28 
 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 
 37 #define PCF2127_OSF             BIT(7)  /* Oscillator Fail flag */
 38 
 39 static struct i2c_driver pcf2127_driver;
 40 
 41 struct pcf2127 {
 42         struct rtc_device *rtc;
 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  */
 49 static int pcf2127_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 50 {
 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 
 60         if (buf[PCF2127_REG_CTRL3] & PCF2127_REG_CTRL3_BLF)
 61                 dev_info(&client->dev,
 62                         "low voltage detected, check/replace RTC battery.\n");
 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                  */
 69                 dev_warn(&client->dev,
 70                          "oscillator stop detected, date/time is not reliable\n");
 71                 return -EINVAL;
 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 
100         return rtc_valid_tm(tm);
101 }
102 
103 static 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 */
118         buf[i++] = bin2bcd(tm->tm_sec); /* this will also clear OSF flag */
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
142 static int pcf2127_rtc_ioctl(struct device *dev,
143                                 unsigned int cmd, unsigned long arg)
144 {
145         struct i2c_client *client = to_i2c_client(dev);
146         unsigned char buf = PCF2127_REG_CTRL3;
147         int touser;
148         int ret;
149 
150         switch (cmd) {
151         case RTC_VL_READ:
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;
165 
166                 if (copy_to_user((void __user *)arg, &touser, sizeof(int)))
167                         return -EFAULT;
168                 return 0;
169         default:
170                 return -ENOIOCTLCMD;
171         }
172 }
173 #else
174 #define pcf2127_rtc_ioctl NULL
175 #endif
176 
177 static 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 
182 static 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 
187 static 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 
193 static 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 
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 
214         return PTR_ERR_OR_ZERO(pcf2127->rtc);
215 }
216 
217 static const struct i2c_device_id pcf2127_id[] = {
218         { "pcf2127", 0 },
219         { }
220 };
221 MODULE_DEVICE_TABLE(i2c, pcf2127_id);
222 
223 #ifdef CONFIG_OF
224 static const struct of_device_id pcf2127_of_match[] = {
225         { .compatible = "nxp,pcf2127" },
226         {}
227 };
228 MODULE_DEVICE_TABLE(of, pcf2127_of_match);
229 #endif
230 
231 static struct i2c_driver pcf2127_driver = {
232         .driver         = {
233                 .name   = "rtc-pcf2127",
234                 .of_match_table = of_match_ptr(pcf2127_of_match),
235         },
236         .probe          = pcf2127_probe,
237         .id_table       = pcf2127_id,
238 };
239 
240 module_i2c_driver(pcf2127_driver);
241 
242 MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>");
243 MODULE_DESCRIPTION("NXP PCF2127 RTC driver");
244 MODULE_LICENSE("GPL v2");
245 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us