diff options
| -rw-r--r-- | drivers/rtc/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/rtc/rtc-ds3232.c | 119 |
2 files changed, 127 insertions, 0 deletions
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 0e5044cd84dd..d0e4b4a1c2a1 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -802,6 +802,14 @@ config RTC_DRV_DS3232 This driver can also be built as a module. If so, the module will be called rtc-ds3232. +config RTC_DRV_DS3232_HWMON + bool "HWMON support for Dallas/Maxim DS3232/DS3234" + depends on RTC_DRV_DS3232 && HWMON && !(RTC_DRV_DS3232=y && HWMON=m) + default y + help + Say Y here if you want to expose temperature sensor data on + rtc-ds3232 + config RTC_DRV_PCF2127 tristate "NXP PCF2127" depends on RTC_I2C_AND_SPI diff --git a/drivers/rtc/rtc-ds3232.c b/drivers/rtc/rtc-ds3232.c index deff431a37c4..0550f7ba464f 100644 --- a/drivers/rtc/rtc-ds3232.c +++ b/drivers/rtc/rtc-ds3232.c @@ -22,6 +22,7 @@ #include <linux/bcd.h> #include <linux/slab.h> #include <linux/regmap.h> +#include <linux/hwmon.h> #define DS3232_REG_SECONDS 0x00 #define DS3232_REG_MINUTES 0x01 @@ -46,6 +47,8 @@ # define DS3232_REG_SR_A2F 0x02 # define DS3232_REG_SR_A1F 0x01 +#define DS3232_REG_TEMPERATURE 0x11 + struct ds3232 { struct device *dev; struct regmap *regmap; @@ -275,6 +278,120 @@ static int ds3232_update_alarm(struct device *dev, unsigned int enabled) return ret; } +/* + * Temperature sensor support for ds3232/ds3234 devices. + * A user-initiated temperature conversion is not started by this function, + * so the temperature is updated once every 64 seconds. + */ +static int ds3232_hwmon_read_temp(struct device *dev, long int *mC) +{ + struct ds3232 *ds3232 = dev_get_drvdata(dev); + u8 temp_buf[2]; + s16 temp; + int ret; + + ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_TEMPERATURE, temp_buf, + sizeof(temp_buf)); + if (ret < 0) + return ret; + + /* + * Temperature is represented as a 10-bit code with a resolution of + * 0.25 degree celsius and encoded in two's complement format. + */ + temp = (temp_buf[0] << 8) | temp_buf[1]; + temp >>= 6; + *mC = temp * 250; + + return 0; +} + +static umode_t ds3232_hwmon_is_visible(const void *data, + enum hwmon_sensor_types type, + u32 attr, int channel) +{ + if (type != hwmon_temp) + return 0; + + switch (attr) { + case hwmon_temp_input: + return 0444; + default: + return 0; + } +} + +static int ds3232_hwmon_read(struct device *dev, + enum hwmon_sensor_types type, + u32 attr, int channel, long *temp) +{ + int err; + + switch (attr) { + case hwmon_temp_input: + err = ds3232_hwmon_read_temp(dev, temp); + break; + default: + err = -EOPNOTSUPP; + break; + } + + return err; +} + +static u32 ds3232_hwmon_chip_config[] = { + HWMON_C_REGISTER_TZ, + 0 +}; + +static const struct hwmon_channel_info ds3232_hwmon_chip = { + .type = hwmon_chip, + .config = ds3232_hwmon_chip_config, +}; + +static u32 ds3232_hwmon_temp_config[] = { + HWMON_T_INPUT, + 0 +}; + +static const struct hwmon_channel_info ds3232_hwmon_temp = { + .type = hwmon_temp, + .config = ds3232_hwmon_temp_config, +}; + +static const struct hwmon_channel_info *ds3232_hwmon_info[] = { + &ds3232_hwmon_chip, + &ds3232_hwmon_temp, + NULL +}; + +static const struct hwmon_ops ds3232_hwmon_hwmon_ops = { + .is_visible = ds3232_hwmon_is_visible, + .read = ds3232_hwmon_read, +}; + +static const struct hwmon_chip_info ds3232_hwmon_chip_info = { + .ops = &ds3232_hwmon_hwmon_ops, + .info = ds3232_hwmon_info, +}; + +static void ds3232_hwmon_register(struct device *dev, const char *name) +{ + struct ds3232 *ds3232 = dev_get_drvdata(dev); + struct device *hwmon_dev; + + if (!IS_ENABLED(CONFIG_RTC_DRV_DS3232_HWMON)) + return; + + hwmon_dev = devm_hwmon_device_register_with_info(dev, name, ds3232, + &ds3232_hwmon_chip_info, + NULL); + if (IS_ERR(hwmon_dev)) { + dev_err(dev, "unable to register hwmon device %ld\n", + PTR_ERR(hwmon_dev)); + } +} + static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct ds3232 *ds3232 = dev_get_drvdata(dev); @@ -366,6 +483,8 @@ static int ds3232_probe(struct device *dev, struct regmap *regmap, int irq, if (ds3232->irq > 0) device_init_wakeup(dev, 1); + ds3232_hwmon_register(dev, name); + ds3232->rtc = devm_rtc_device_register(dev, name, &ds3232_rtc_ops, THIS_MODULE); if (IS_ERR(ds3232->rtc)) |