mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-02 16:44:10 +08:00
8d816c1eaa
The isl12022 has built-in temperature compensation effective over the range -40C to +85C. It exposes the average of the last two temperature measurements as a 10-bit value in half-Kelvins. Make this available via the hwmon framework. Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Link: https://lore.kernel.org/r/20221104110225.2219761-1-linux@rasmusvillemoes.dk Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
299 lines
7.4 KiB
C
299 lines
7.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* An I2C driver for the Intersil ISL 12022
|
|
*
|
|
* Author: Roman Fietze <roman.fietze@telemotive.de>
|
|
*
|
|
* Based on the Philips PCF8563 RTC
|
|
* by Alessandro Zummo <a.zummo@towertech.it>.
|
|
*/
|
|
|
|
#include <linux/i2c.h>
|
|
#include <linux/bcd.h>
|
|
#include <linux/rtc.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/module.h>
|
|
#include <linux/err.h>
|
|
#include <linux/of.h>
|
|
#include <linux/of_device.h>
|
|
#include <linux/regmap.h>
|
|
#include <linux/hwmon.h>
|
|
|
|
/* ISL register offsets */
|
|
#define ISL12022_REG_SC 0x00
|
|
#define ISL12022_REG_MN 0x01
|
|
#define ISL12022_REG_HR 0x02
|
|
#define ISL12022_REG_DT 0x03
|
|
#define ISL12022_REG_MO 0x04
|
|
#define ISL12022_REG_YR 0x05
|
|
#define ISL12022_REG_DW 0x06
|
|
|
|
#define ISL12022_REG_SR 0x07
|
|
#define ISL12022_REG_INT 0x08
|
|
|
|
#define ISL12022_REG_BETA 0x0d
|
|
#define ISL12022_REG_TEMP_L 0x28
|
|
|
|
/* ISL register bits */
|
|
#define ISL12022_HR_MIL (1 << 7) /* military or 24 hour time */
|
|
|
|
#define ISL12022_SR_LBAT85 (1 << 2)
|
|
#define ISL12022_SR_LBAT75 (1 << 1)
|
|
|
|
#define ISL12022_INT_WRTC (1 << 6)
|
|
|
|
#define ISL12022_BETA_TSE (1 << 7)
|
|
|
|
static struct i2c_driver isl12022_driver;
|
|
|
|
struct isl12022 {
|
|
struct rtc_device *rtc;
|
|
struct regmap *regmap;
|
|
};
|
|
|
|
static umode_t isl12022_hwmon_is_visible(const void *data,
|
|
enum hwmon_sensor_types type,
|
|
u32 attr, int channel)
|
|
{
|
|
if (type == hwmon_temp && attr == hwmon_temp_input)
|
|
return 0444;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* A user-initiated temperature conversion is not started by this function,
|
|
* so the temperature is updated once every ~60 seconds.
|
|
*/
|
|
static int isl12022_hwmon_read_temp(struct device *dev, long *mC)
|
|
{
|
|
struct isl12022 *isl12022 = dev_get_drvdata(dev);
|
|
struct regmap *regmap = isl12022->regmap;
|
|
u8 temp_buf[2];
|
|
int temp, ret;
|
|
|
|
ret = regmap_bulk_read(regmap, ISL12022_REG_TEMP_L,
|
|
temp_buf, sizeof(temp_buf));
|
|
if (ret)
|
|
return ret;
|
|
/*
|
|
* Temperature is represented as a 10-bit number, unit half-Kelvins.
|
|
*/
|
|
temp = (temp_buf[1] << 8) | temp_buf[0];
|
|
temp *= 500;
|
|
temp -= 273000;
|
|
|
|
*mC = temp;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int isl12022_hwmon_read(struct device *dev,
|
|
enum hwmon_sensor_types type,
|
|
u32 attr, int channel, long *val)
|
|
{
|
|
if (type == hwmon_temp && attr == hwmon_temp_input)
|
|
return isl12022_hwmon_read_temp(dev, val);
|
|
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
static const struct hwmon_channel_info *isl12022_hwmon_info[] = {
|
|
HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
|
|
NULL
|
|
};
|
|
|
|
static const struct hwmon_ops isl12022_hwmon_ops = {
|
|
.is_visible = isl12022_hwmon_is_visible,
|
|
.read = isl12022_hwmon_read,
|
|
};
|
|
|
|
static const struct hwmon_chip_info isl12022_hwmon_chip_info = {
|
|
.ops = &isl12022_hwmon_ops,
|
|
.info = isl12022_hwmon_info,
|
|
};
|
|
|
|
static void isl12022_hwmon_register(struct device *dev)
|
|
{
|
|
struct isl12022 *isl12022;
|
|
struct device *hwmon;
|
|
int ret;
|
|
|
|
if (!IS_REACHABLE(CONFIG_HWMON))
|
|
return;
|
|
|
|
isl12022 = dev_get_drvdata(dev);
|
|
|
|
ret = regmap_update_bits(isl12022->regmap, ISL12022_REG_BETA,
|
|
ISL12022_BETA_TSE, ISL12022_BETA_TSE);
|
|
if (ret) {
|
|
dev_warn(dev, "unable to enable temperature sensor\n");
|
|
return;
|
|
}
|
|
|
|
hwmon = devm_hwmon_device_register_with_info(dev, "isl12022", isl12022,
|
|
&isl12022_hwmon_chip_info,
|
|
NULL);
|
|
if (IS_ERR(hwmon))
|
|
dev_warn(dev, "unable to register hwmon device: %pe\n", hwmon);
|
|
}
|
|
|
|
/*
|
|
* In the routines that deal directly with the isl12022 hardware, we use
|
|
* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
|
|
*/
|
|
static int isl12022_rtc_read_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
struct isl12022 *isl12022 = dev_get_drvdata(dev);
|
|
struct regmap *regmap = isl12022->regmap;
|
|
uint8_t buf[ISL12022_REG_INT + 1];
|
|
int ret;
|
|
|
|
ret = regmap_bulk_read(regmap, ISL12022_REG_SC, buf, sizeof(buf));
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 | ISL12022_SR_LBAT75)) {
|
|
dev_warn(dev,
|
|
"voltage dropped below %u%%, "
|
|
"date and time is not reliable.\n",
|
|
buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75);
|
|
}
|
|
|
|
dev_dbg(dev,
|
|
"%s: raw data is sec=%02x, min=%02x, hr=%02x, "
|
|
"mday=%02x, mon=%02x, year=%02x, wday=%02x, "
|
|
"sr=%02x, int=%02x",
|
|
__func__,
|
|
buf[ISL12022_REG_SC],
|
|
buf[ISL12022_REG_MN],
|
|
buf[ISL12022_REG_HR],
|
|
buf[ISL12022_REG_DT],
|
|
buf[ISL12022_REG_MO],
|
|
buf[ISL12022_REG_YR],
|
|
buf[ISL12022_REG_DW],
|
|
buf[ISL12022_REG_SR],
|
|
buf[ISL12022_REG_INT]);
|
|
|
|
tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F);
|
|
tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F);
|
|
tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F);
|
|
tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F);
|
|
tm->tm_wday = buf[ISL12022_REG_DW] & 0x07;
|
|
tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1;
|
|
tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100;
|
|
|
|
dev_dbg(dev, "%s: %ptR\n", __func__, tm);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int isl12022_rtc_set_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
struct isl12022 *isl12022 = dev_get_drvdata(dev);
|
|
struct regmap *regmap = isl12022->regmap;
|
|
int ret;
|
|
uint8_t buf[ISL12022_REG_DW + 1];
|
|
|
|
dev_dbg(dev, "%s: %ptR\n", __func__, tm);
|
|
|
|
/* Ensure the write enable bit is set. */
|
|
ret = regmap_update_bits(regmap, ISL12022_REG_INT,
|
|
ISL12022_INT_WRTC, ISL12022_INT_WRTC);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* hours, minutes and seconds */
|
|
buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
|
|
buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
|
|
buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) | ISL12022_HR_MIL;
|
|
|
|
buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);
|
|
|
|
/* month, 1 - 12 */
|
|
buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);
|
|
|
|
/* year and century */
|
|
buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);
|
|
|
|
buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;
|
|
|
|
return regmap_bulk_write(isl12022->regmap, ISL12022_REG_SC,
|
|
buf, sizeof(buf));
|
|
}
|
|
|
|
static const struct rtc_class_ops isl12022_rtc_ops = {
|
|
.read_time = isl12022_rtc_read_time,
|
|
.set_time = isl12022_rtc_set_time,
|
|
};
|
|
|
|
static const struct regmap_config regmap_config = {
|
|
.reg_bits = 8,
|
|
.val_bits = 8,
|
|
.use_single_write = true,
|
|
};
|
|
|
|
static int isl12022_probe(struct i2c_client *client)
|
|
{
|
|
struct isl12022 *isl12022;
|
|
|
|
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
|
|
return -ENODEV;
|
|
|
|
isl12022 = devm_kzalloc(&client->dev, sizeof(struct isl12022),
|
|
GFP_KERNEL);
|
|
if (!isl12022)
|
|
return -ENOMEM;
|
|
dev_set_drvdata(&client->dev, isl12022);
|
|
|
|
isl12022->regmap = devm_regmap_init_i2c(client, ®map_config);
|
|
if (IS_ERR(isl12022->regmap)) {
|
|
dev_err(&client->dev, "regmap allocation failed\n");
|
|
return PTR_ERR(isl12022->regmap);
|
|
}
|
|
|
|
isl12022_hwmon_register(&client->dev);
|
|
|
|
isl12022->rtc = devm_rtc_allocate_device(&client->dev);
|
|
if (IS_ERR(isl12022->rtc))
|
|
return PTR_ERR(isl12022->rtc);
|
|
|
|
isl12022->rtc->ops = &isl12022_rtc_ops;
|
|
isl12022->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
|
|
isl12022->rtc->range_max = RTC_TIMESTAMP_END_2099;
|
|
|
|
return devm_rtc_register_device(isl12022->rtc);
|
|
}
|
|
|
|
#ifdef CONFIG_OF
|
|
static const struct of_device_id isl12022_dt_match[] = {
|
|
{ .compatible = "isl,isl12022" }, /* for backward compat., don't use */
|
|
{ .compatible = "isil,isl12022" },
|
|
{ },
|
|
};
|
|
MODULE_DEVICE_TABLE(of, isl12022_dt_match);
|
|
#endif
|
|
|
|
static const struct i2c_device_id isl12022_id[] = {
|
|
{ "isl12022", 0 },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, isl12022_id);
|
|
|
|
static struct i2c_driver isl12022_driver = {
|
|
.driver = {
|
|
.name = "rtc-isl12022",
|
|
#ifdef CONFIG_OF
|
|
.of_match_table = of_match_ptr(isl12022_dt_match),
|
|
#endif
|
|
},
|
|
.probe_new = isl12022_probe,
|
|
.id_table = isl12022_id,
|
|
};
|
|
|
|
module_i2c_driver(isl12022_driver);
|
|
|
|
MODULE_AUTHOR("roman.fietze@telemotive.de");
|
|
MODULE_DESCRIPTION("ISL 12022 RTC driver");
|
|
MODULE_LICENSE("GPL");
|