436 lines
10 KiB
C
436 lines
10 KiB
C
/*
|
|
* An I2C and SPI driver for the NXP PCF2127/29 RTC
|
|
* Copyright 2013 Til-Technologies
|
|
*
|
|
* Author: Renaud Cerrato <r.cerrato@til-technologies.fr>
|
|
*
|
|
* based on the other drivers in this same directory.
|
|
*
|
|
* Datasheet: http://cache.nxp.com/documents/data_sheet/PCF2127.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/spi/spi.h>
|
|
#include <linux/bcd.h>
|
|
#include <linux/rtc.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/module.h>
|
|
#include <linux/of.h>
|
|
#include <linux/regmap.h>
|
|
|
|
#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_CTRL3_BLF BIT(2)
|
|
|
|
#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)
|
|
|
|
#define PCF2127_OSF BIT(7) /* Oscillator Fail flag */
|
|
|
|
struct pcf2127 {
|
|
struct rtc_device *rtc;
|
|
struct regmap *regmap;
|
|
};
|
|
|
|
/*
|
|
* 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_rtc_read_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
|
|
unsigned char buf[10];
|
|
int ret;
|
|
|
|
ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_CTRL1, buf,
|
|
sizeof(buf));
|
|
if (ret) {
|
|
dev_err(dev, "%s: read error\n", __func__);
|
|
return ret;
|
|
}
|
|
|
|
if (buf[PCF2127_REG_CTRL3] & PCF2127_REG_CTRL3_BLF)
|
|
dev_info(dev,
|
|
"low voltage detected, check/replace RTC battery.\n");
|
|
|
|
if (buf[PCF2127_REG_SC] & PCF2127_OSF) {
|
|
/*
|
|
* no need clear the flag here,
|
|
* it will be cleared once the new date is saved
|
|
*/
|
|
dev_warn(dev,
|
|
"oscillator stop detected, date/time is not reliable\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
dev_dbg(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(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);
|
|
|
|
return rtc_valid_tm(tm);
|
|
}
|
|
|
|
static int pcf2127_rtc_set_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
|
|
unsigned char buf[7];
|
|
int i = 0, err;
|
|
|
|
dev_dbg(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);
|
|
|
|
/* hours, minutes and seconds */
|
|
buf[i++] = bin2bcd(tm->tm_sec); /* this will also clear OSF flag */
|
|
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 = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_SC, buf, i);
|
|
if (err) {
|
|
dev_err(dev,
|
|
"%s: err=%d", __func__, err);
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_RTC_INTF_DEV
|
|
static int pcf2127_rtc_ioctl(struct device *dev,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
|
|
int touser;
|
|
int ret;
|
|
|
|
switch (cmd) {
|
|
case RTC_VL_READ:
|
|
ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL3, &touser);
|
|
if (ret)
|
|
return ret;
|
|
|
|
touser = touser & PCF2127_REG_CTRL3_BLF ? 1 : 0;
|
|
|
|
if (copy_to_user((void __user *)arg, &touser, sizeof(int)))
|
|
return -EFAULT;
|
|
return 0;
|
|
default:
|
|
return -ENOIOCTLCMD;
|
|
}
|
|
}
|
|
#else
|
|
#define pcf2127_rtc_ioctl NULL
|
|
#endif
|
|
|
|
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 device *dev, struct regmap *regmap,
|
|
const char *name)
|
|
{
|
|
struct pcf2127 *pcf2127;
|
|
|
|
dev_dbg(dev, "%s\n", __func__);
|
|
|
|
pcf2127 = devm_kzalloc(dev, sizeof(*pcf2127), GFP_KERNEL);
|
|
if (!pcf2127)
|
|
return -ENOMEM;
|
|
|
|
pcf2127->regmap = regmap;
|
|
|
|
dev_set_drvdata(dev, pcf2127);
|
|
|
|
pcf2127->rtc = devm_rtc_device_register(dev, name, &pcf2127_rtc_ops,
|
|
THIS_MODULE);
|
|
|
|
return PTR_ERR_OR_ZERO(pcf2127->rtc);
|
|
}
|
|
|
|
#ifdef CONFIG_OF
|
|
static const struct of_device_id pcf2127_of_match[] = {
|
|
{ .compatible = "nxp,pcf2127" },
|
|
{ .compatible = "nxp,pcf2129" },
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(of, pcf2127_of_match);
|
|
#endif
|
|
|
|
#if IS_ENABLED(CONFIG_I2C)
|
|
|
|
static int pcf2127_i2c_write(void *context, const void *data, size_t count)
|
|
{
|
|
struct device *dev = context;
|
|
struct i2c_client *client = to_i2c_client(dev);
|
|
int ret;
|
|
|
|
ret = i2c_master_send(client, data, count);
|
|
if (ret != count)
|
|
return ret < 0 ? ret : -EIO;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pcf2127_i2c_gather_write(void *context,
|
|
const void *reg, size_t reg_size,
|
|
const void *val, size_t val_size)
|
|
{
|
|
struct device *dev = context;
|
|
struct i2c_client *client = to_i2c_client(dev);
|
|
int ret;
|
|
void *buf;
|
|
|
|
if (WARN_ON(reg_size != 1))
|
|
return -EINVAL;
|
|
|
|
buf = kmalloc(val_size + 1, GFP_KERNEL);
|
|
if (!buf)
|
|
return -ENOMEM;
|
|
|
|
memcpy(buf, reg, 1);
|
|
memcpy(buf + 1, val, val_size);
|
|
|
|
ret = i2c_master_send(client, buf, val_size + 1);
|
|
if (ret != val_size + 1)
|
|
return ret < 0 ? ret : -EIO;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pcf2127_i2c_read(void *context, const void *reg, size_t reg_size,
|
|
void *val, size_t val_size)
|
|
{
|
|
struct device *dev = context;
|
|
struct i2c_client *client = to_i2c_client(dev);
|
|
int ret;
|
|
|
|
if (WARN_ON(reg_size != 1))
|
|
return -EINVAL;
|
|
|
|
ret = i2c_master_send(client, reg, 1);
|
|
if (ret != 1)
|
|
return ret < 0 ? ret : -EIO;
|
|
|
|
ret = i2c_master_recv(client, val, val_size);
|
|
if (ret != val_size)
|
|
return ret < 0 ? ret : -EIO;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* The reason we need this custom regmap_bus instead of using regmap_init_i2c()
|
|
* is that the STOP condition is required between set register address and
|
|
* read register data when reading from registers.
|
|
*/
|
|
static const struct regmap_bus pcf2127_i2c_regmap = {
|
|
.write = pcf2127_i2c_write,
|
|
.gather_write = pcf2127_i2c_gather_write,
|
|
.read = pcf2127_i2c_read,
|
|
};
|
|
|
|
static struct i2c_driver pcf2127_i2c_driver;
|
|
|
|
static int pcf2127_i2c_probe(struct i2c_client *client,
|
|
const struct i2c_device_id *id)
|
|
{
|
|
struct regmap *regmap;
|
|
static const struct regmap_config config = {
|
|
.reg_bits = 8,
|
|
.val_bits = 8,
|
|
};
|
|
|
|
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
|
|
return -ENODEV;
|
|
|
|
regmap = devm_regmap_init(&client->dev, &pcf2127_i2c_regmap,
|
|
&client->dev, &config);
|
|
if (IS_ERR(regmap)) {
|
|
dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
|
|
__func__, PTR_ERR(regmap));
|
|
return PTR_ERR(regmap);
|
|
}
|
|
|
|
return pcf2127_probe(&client->dev, regmap,
|
|
pcf2127_i2c_driver.driver.name);
|
|
}
|
|
|
|
static const struct i2c_device_id pcf2127_i2c_id[] = {
|
|
{ "pcf2127", 0 },
|
|
{ "pcf2129", 0 },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, pcf2127_i2c_id);
|
|
|
|
static struct i2c_driver pcf2127_i2c_driver = {
|
|
.driver = {
|
|
.name = "rtc-pcf2127-i2c",
|
|
.of_match_table = of_match_ptr(pcf2127_of_match),
|
|
},
|
|
.probe = pcf2127_i2c_probe,
|
|
.id_table = pcf2127_i2c_id,
|
|
};
|
|
|
|
static int pcf2127_i2c_register_driver(void)
|
|
{
|
|
return i2c_add_driver(&pcf2127_i2c_driver);
|
|
}
|
|
|
|
static void pcf2127_i2c_unregister_driver(void)
|
|
{
|
|
i2c_del_driver(&pcf2127_i2c_driver);
|
|
}
|
|
|
|
#else
|
|
|
|
static int pcf2127_i2c_register_driver(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void pcf2127_i2c_unregister_driver(void)
|
|
{
|
|
}
|
|
|
|
#endif
|
|
|
|
#if IS_ENABLED(CONFIG_SPI_MASTER)
|
|
|
|
static struct spi_driver pcf2127_spi_driver;
|
|
|
|
static int pcf2127_spi_probe(struct spi_device *spi)
|
|
{
|
|
static const struct regmap_config config = {
|
|
.reg_bits = 8,
|
|
.val_bits = 8,
|
|
.read_flag_mask = 0xa0,
|
|
.write_flag_mask = 0x20,
|
|
};
|
|
struct regmap *regmap;
|
|
|
|
regmap = devm_regmap_init_spi(spi, &config);
|
|
if (IS_ERR(regmap)) {
|
|
dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
|
|
__func__, PTR_ERR(regmap));
|
|
return PTR_ERR(regmap);
|
|
}
|
|
|
|
return pcf2127_probe(&spi->dev, regmap, pcf2127_spi_driver.driver.name);
|
|
}
|
|
|
|
static const struct spi_device_id pcf2127_spi_id[] = {
|
|
{ "pcf2127", 0 },
|
|
{ "pcf2129", 0 },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(spi, pcf2127_spi_id);
|
|
|
|
static struct spi_driver pcf2127_spi_driver = {
|
|
.driver = {
|
|
.name = "rtc-pcf2127-spi",
|
|
.of_match_table = of_match_ptr(pcf2127_of_match),
|
|
},
|
|
.probe = pcf2127_spi_probe,
|
|
.id_table = pcf2127_spi_id,
|
|
};
|
|
|
|
static int pcf2127_spi_register_driver(void)
|
|
{
|
|
return spi_register_driver(&pcf2127_spi_driver);
|
|
}
|
|
|
|
static void pcf2127_spi_unregister_driver(void)
|
|
{
|
|
spi_unregister_driver(&pcf2127_spi_driver);
|
|
}
|
|
|
|
#else
|
|
|
|
static int pcf2127_spi_register_driver(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void pcf2127_spi_unregister_driver(void)
|
|
{
|
|
}
|
|
|
|
#endif
|
|
|
|
static int __init pcf2127_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = pcf2127_i2c_register_driver();
|
|
if (ret) {
|
|
pr_err("Failed to register pcf2127 i2c driver: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
ret = pcf2127_spi_register_driver();
|
|
if (ret) {
|
|
pr_err("Failed to register pcf2127 spi driver: %d\n", ret);
|
|
pcf2127_i2c_unregister_driver();
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
module_init(pcf2127_init)
|
|
|
|
static void __exit pcf2127_exit(void)
|
|
{
|
|
pcf2127_spi_unregister_driver();
|
|
pcf2127_i2c_unregister_driver();
|
|
}
|
|
module_exit(pcf2127_exit)
|
|
|
|
MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>");
|
|
MODULE_DESCRIPTION("NXP PCF2127/29 RTC driver");
|
|
MODULE_LICENSE("GPL v2");
|