Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 | /*
* An I2C driver for the NXP PCF2127 RTC
* Copyright 2013 Til-Technologies
*
* Author: Renaud Cerrato <r.cerrato@til-technologies.fr>
*
* based on the other drivers in this same directory.
*
* http://www.nxp.com/documents/data_sheet/PCF2127AT.pdf
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/i2c.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/of.h>
#define DRV_VERSION "0.0.1"
#define PCF2127_REG_CTRL1 (0x00) /* Control Register 1 */
#define PCF2127_REG_CTRL2 (0x01) /* Control Register 2 */
#define PCF2127_REG_CTRL3 (0x02) /* Control Register 3 */
#define PCF2127_REG_SC (0x03) /* datetime */
#define PCF2127_REG_MN (0x04)
#define PCF2127_REG_HR (0x05)
#define PCF2127_REG_DM (0x06)
#define PCF2127_REG_DW (0x07)
#define PCF2127_REG_MO (0x08)
#define PCF2127_REG_YR (0x09)
static struct i2c_driver pcf2127_driver;
struct pcf2127 {
struct rtc_device *rtc;
int voltage_low; /* indicates if a low_voltage was detected */
};
/*
* In the routines that deal directly with the pcf2127 hardware, we use
* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
*/
static int pcf2127_get_datetime(struct i2c_client *client, struct rtc_time *tm)
{
struct pcf2127 *pcf2127 = i2c_get_clientdata(client);
unsigned char buf[10] = { PCF2127_REG_CTRL1 };
/* read registers */
if (i2c_master_send(client, buf, 1) != 1 ||
i2c_master_recv(client, buf, sizeof(buf)) != sizeof(buf)) {
dev_err(&client->dev, "%s: read error\n", __func__);
return -EIO;
}
if (buf[PCF2127_REG_CTRL3] & 0x04) {
pcf2127->voltage_low = 1;
dev_info(&client->dev,
"low voltage detected, date/time is not reliable.\n");
}
dev_dbg(&client->dev,
"%s: raw data is cr1=%02x, cr2=%02x, cr3=%02x, "
"sec=%02x, min=%02x, hr=%02x, "
"mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
__func__,
buf[0], buf[1], buf[2],
buf[3], buf[4], buf[5],
buf[6], buf[7], buf[8], buf[9]);
tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F);
tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F);
tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F); /* rtc hr 0-23 */
tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F);
tm->tm_wday = buf[PCF2127_REG_DW] & 0x07;
tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]);
if (tm->tm_year < 70)
tm->tm_year += 100; /* assume we are in 1970...2069 */
dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
"mday=%d, mon=%d, year=%d, wday=%d\n",
__func__,
tm->tm_sec, tm->tm_min, tm->tm_hour,
tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
/* the clock can give out invalid datetime, but we cannot return
* -EINVAL otherwise hwclock will refuse to set the time on bootup.
*/
if (rtc_valid_tm(tm) < 0)
dev_err(&client->dev, "retrieved date/time is not valid.\n");
return 0;
}
static int pcf2127_set_datetime(struct i2c_client *client, struct rtc_time *tm)
{
unsigned char buf[8];
int i = 0, err;
dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
"mday=%d, mon=%d, year=%d, wday=%d\n",
__func__,
tm->tm_sec, tm->tm_min, tm->tm_hour,
tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
/* start register address */
buf[i++] = PCF2127_REG_SC;
/* hours, minutes and seconds */
buf[i++] = bin2bcd(tm->tm_sec);
buf[i++] = bin2bcd(tm->tm_min);
buf[i++] = bin2bcd(tm->tm_hour);
buf[i++] = bin2bcd(tm->tm_mday);
buf[i++] = tm->tm_wday & 0x07;
/* month, 1 - 12 */
buf[i++] = bin2bcd(tm->tm_mon + 1);
/* year */
buf[i++] = bin2bcd(tm->tm_year % 100);
/* write register's data */
err = i2c_master_send(client, buf, i);
if (err != i) {
dev_err(&client->dev,
"%s: err=%d", __func__, err);
return -EIO;
}
return 0;
}
#ifdef CONFIG_RTC_INTF_DEV
static int pcf2127_rtc_ioctl(struct device *dev,
unsigned int cmd, unsigned long arg)
{
struct pcf2127 *pcf2127 = i2c_get_clientdata(to_i2c_client(dev));
switch (cmd) {
case RTC_VL_READ:
if (pcf2127->voltage_low)
dev_info(dev, "low voltage detected, date/time is not reliable.\n");
if (copy_to_user((void __user *)arg, &pcf2127->voltage_low,
sizeof(int)))
return -EFAULT;
return 0;
default:
return -ENOIOCTLCMD;
}
}
#else
#define pcf2127_rtc_ioctl NULL
#endif
static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
return pcf2127_get_datetime(to_i2c_client(dev), tm);
}
static int pcf2127_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
return pcf2127_set_datetime(to_i2c_client(dev), tm);
}
static const struct rtc_class_ops pcf2127_rtc_ops = {
.ioctl = pcf2127_rtc_ioctl,
.read_time = pcf2127_rtc_read_time,
.set_time = pcf2127_rtc_set_time,
};
static int pcf2127_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct pcf2127 *pcf2127;
dev_dbg(&client->dev, "%s\n", __func__);
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
return -ENODEV;
pcf2127 = devm_kzalloc(&client->dev, sizeof(struct pcf2127),
GFP_KERNEL);
if (!pcf2127)
return -ENOMEM;
dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
i2c_set_clientdata(client, pcf2127);
pcf2127->rtc = devm_rtc_device_register(&client->dev,
pcf2127_driver.driver.name,
&pcf2127_rtc_ops, THIS_MODULE);
return PTR_ERR_OR_ZERO(pcf2127->rtc);
}
static const struct i2c_device_id pcf2127_id[] = {
{ "pcf2127", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, pcf2127_id);
#ifdef CONFIG_OF
static const struct of_device_id pcf2127_of_match[] = {
{ .compatible = "nxp,pcf2127" },
{}
};
MODULE_DEVICE_TABLE(of, pcf2127_of_match);
#endif
static struct i2c_driver pcf2127_driver = {
.driver = {
.name = "rtc-pcf2127",
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(pcf2127_of_match),
},
.probe = pcf2127_probe,
.id_table = pcf2127_id,
};
module_i2c_driver(pcf2127_driver);
MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>");
MODULE_DESCRIPTION("NXP PCF2127 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
|