2017-06-22 1:24 GMT+03:00 Guenter Roeck <linux@xxxxxxxxxxxx>:
> On Wed, Jun 21, 2017 at 05:49:43PM +0300, Kirill Esipov wrote:
>> DS3232/DS3234 has the temperature registers with a resolution of
>> 0.25 degree celsius. This enables to get the value through hwmon.
>>
>> # cat /sys/class/hwmon/hwmon0/temp1_input
>> 37250
>>
>> Signed-off-by: Kirill Esipov <yesipov@xxxxxxxxx>
>> ---
>> drivers/rtc/Kconfig | 9 ++++++
>> drivers/rtc/rtc-ds3232.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++++
>> 2 files changed, 93 insertions(+)
>>
>> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
>> index 8d3b95728326..b4a6a916d4df 100644
>> --- a/drivers/rtc/Kconfig
>> +++ b/drivers/rtc/Kconfig
>> @@ -791,6 +791,15 @@ 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
>> + depends on !(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..f94ff0685942 100644
>> --- a/drivers/rtc/rtc-ds3232.c
>> +++ b/drivers/rtc/rtc-ds3232.c
>> @@ -22,6 +22,8 @@
>> #include <linux/bcd.h>
>> #include <linux/slab.h>
>> #include <linux/regmap.h>
>> +#include <linux/hwmon.h>
>> +#include <linux/hwmon-sysfs.h>
>>
>> #define DS3232_REG_SECONDS 0x00
>> #define DS3232_REG_MINUTES 0x01
>> @@ -275,6 +277,86 @@ static int ds3232_update_alarm(struct device *dev, unsigned int enabled)
>> return ret;
>> }
>>
>> +/*----------------------------------------------------------------------*/
>> +
>> +#ifdef CONFIG_RTC_DRV_DS3232_HWMON
>> +
>> +/*
>> + * Temperature sensor support for ds3232/ds3234 devices.
>> + */
>> +
>> +#define DS3232_REG_TEMPERATURE 0x11
>> +
>> +/*
>> + * 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, s32 *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 ssize_t ds3232_hwmon_show_temp(struct device *dev,
>> + struct device_attribute *attr, char *buf)
>> +{
>> + int ret;
>> + s32 temp;
>> +
>> + ret = ds3232_hwmon_read_temp(dev, &temp);
>> + if (ret < 0)
>> + return ret;
>> +
>> + return sprintf(buf, "%d\n", temp);
>> +}
>> +static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ds3232_hwmon_show_temp,
>> + NULL, 0);
>> +
>> +static struct attribute *ds3232_hwmon_attrs[] = {
>> + &sensor_dev_attr_temp1_input.dev_attr.attr,
>> + NULL,
>> +};
>> +ATTRIBUTE_GROUPS(ds3232_hwmon);
>> +
>> +static void ds3232_hwmon_register(struct device *dev, const char *name)
>> +{
>> + struct ds3232 *ds3232 = dev_get_drvdata(dev);
>> + struct device *hwmon_dev;
>> +
>> + hwmon_dev = devm_hwmon_device_register_with_groups(dev, name, ds3232,
>> + ds3232_hwmon_groups);
>
> Any reason for not using devm_hwmon_device_register_with_info() ?
>
Just to keep uniformity, because other rtc drivers with hwmon
(rtc-ds1307, rtc-rv3029c2) use
devm_hwmon_device_register_with_groups().
> Guenter
>
>> + if (IS_ERR(hwmon_dev)) {
>> + dev_warn(dev, "unable to register hwmon device %ld\n",
>> + PTR_ERR(hwmon_dev));
>> + }
>> +}
>> +
>> +#else
>> +
>> +static void ds3232_hwmon_register(struct ds3232 *ds3232)
>> +{
>> +}
>> +
>> +#endif
>> +
>> static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled)
>> {
>> struct ds3232 *ds3232 = dev_get_drvdata(dev);
>> @@ -366,6 +448,8 @@ 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))
--
Kirill Esipov
