| Message ID | 1453574832-21908-1-git-send-email-akinobu.mita@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
On 01/23/2016 10:47 AM, Akinobu Mita wrote: > DS3231 has the temperature registers with a resolution of 0.25 > degree celsius. This enables to get the value through hwmon. > > # cat /sys/class/i2c-adapter/i2c-2/2-0068/hwmon/hwmon0/temp1_input > 21000 > > Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> > Cc: Alessandro Zummo <a.zummo@towertech.it> > Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com> > Cc: rtc-linux@googlegroups.com > Cc: Jean Delvare <jdelvare@suse.com> > Cc: Guenter Roeck <linux@roeck-us.net> > Cc: lm-sensors@lm-sensors.org [ I would suggest to drop the Cc: mailing lists for future submissions. Sure, you want to send the patch to the lists, but that doesn't mean that the lists should be in the commit log. ] Much better. Couple of nitpicks below. Feel free to resubmit or not with those changed. Either case, Acked-by: Guenter Roeck <linux@roeck-us.net> > --- > * v3 (all changes are suggested by Guenter Roeck) > - add RTC_DRV_DS1307_HWMON config option to fix an issue when the ds1307 > driver is built into the kernel but hwmon is built as module. > - don't start user-initiated temperature conversion when reading temperature, > just relying on internal/automatic conversions. > > drivers/rtc/Kconfig | 9 +++++ > drivers/rtc/rtc-ds1307.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 102 insertions(+) > > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig > index 2a52424..73a7e51 100644 > --- a/drivers/rtc/Kconfig > +++ b/drivers/rtc/Kconfig > @@ -212,6 +212,15 @@ config RTC_DRV_DS1307 > This driver can also be built as a module. If so, the module > will be called rtc-ds1307. > > +config RTC_DRV_DS1307_HWMON > + bool "HWMON support for rtc-ds1307" > + depends on RTC_DRV_DS1307 && HWMON > + depends on !(RTC_DRV_DS1307=y && HWMON=m) > + default y > + help > + Say Y here if you want to expose temperature sensor data on > + rtc-ds1307 (only DS3231) > + > config RTC_DRV_DS1374 > tristate "Dallas/Maxim DS1374" > help > diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c > index aa705bb..3712fb3 100644 > --- a/drivers/rtc/rtc-ds1307.c > +++ b/drivers/rtc/rtc-ds1307.c > @@ -19,6 +19,9 @@ > #include <linux/rtc.h> > #include <linux/slab.h> > #include <linux/string.h> > +#include <linux/delay.h> Now unnecessary. > +#include <linux/hwmon.h> > +#include <linux/hwmon-sysfs.h> > > /* > * We can't determine type by probing, but if we expect pre-Linux code > @@ -851,6 +854,94 @@ out: > return; > } > > +/*----------------------------------------------------------------------*/ > + > +#ifdef CONFIG_RTC_DRV_DS1307_HWMON > + > +/* > + * Temperature sensor support for ds3231 devices. > + */ > + > +#define DS3231_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 ds3231_hwmon_read_temp(struct device *dev, s16 *mC) > +{ > + struct ds1307 *ds1307 = dev_get_drvdata(dev); > + u8 temp_buf[2]; > + s16 temp; > + s32 ret; int ret ? > + > + ret = ds1307->read_block_data(ds1307->client, DS3231_REG_TEMPERATURE, > + sizeof(temp_buf), temp_buf); > + if (ret < 0) > + return ret; > + if (ret != sizeof(temp_buf)) > + return -EIO; > + > + /* > + * 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 ds3231_hwmon_show_temp(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + int ret; > + s16 temp; > + > + ret = ds3231_hwmon_read_temp(dev, &temp); > + if (ret) > + return ret; > + > + return sprintf(buf, "%d\n", temp); > +} > +static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ds3231_hwmon_show_temp, > + NULL, 0); > + > +static struct attribute *ds3231_hwmon_attrs[] = { > + &sensor_dev_attr_temp1_input.dev_attr.attr, > + NULL, > +}; > +ATTRIBUTE_GROUPS(ds3231_hwmon); > + > +static int ds1307_hwmon_register(struct ds1307 *ds1307) The return value is never used, so you might as well return void. > +{ > + struct device *dev; > + > + if (ds1307->type != ds_3231) > + return 0; > + > + dev = devm_hwmon_device_register_with_groups(&ds1307->client->dev, > + ds1307->client->name, > + ds1307, ds3231_hwmon_groups); > + if (IS_ERR(dev)) { > + dev_warn(&ds1307->client->dev, > + "unable to register hwmon device %ld\n", PTR_ERR(dev)); > + return PTR_ERR(dev); > + } > + > + return 0; > +} > + > +#else > + > +static int ds1307_hwmon_register(struct ds1307 *ds1307) > +{ > + return 0; > +} > + > +#endif > + > static int ds1307_probe(struct i2c_client *client, > const struct i2c_device_id *id) > { > @@ -1191,6 +1282,8 @@ read_rtc: > } > } > > + ds1307_hwmon_register(ds1307); > + > return 0; > > exit: >
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 2a52424..73a7e51 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -212,6 +212,15 @@ config RTC_DRV_DS1307 This driver can also be built as a module. If so, the module will be called rtc-ds1307. +config RTC_DRV_DS1307_HWMON + bool "HWMON support for rtc-ds1307" + depends on RTC_DRV_DS1307 && HWMON + depends on !(RTC_DRV_DS1307=y && HWMON=m) + default y + help + Say Y here if you want to expose temperature sensor data on + rtc-ds1307 (only DS3231) + config RTC_DRV_DS1374 tristate "Dallas/Maxim DS1374" help diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c index aa705bb..3712fb3 100644 --- a/drivers/rtc/rtc-ds1307.c +++ b/drivers/rtc/rtc-ds1307.c @@ -19,6 +19,9 @@ #include <linux/rtc.h> #include <linux/slab.h> #include <linux/string.h> +#include <linux/delay.h> +#include <linux/hwmon.h> +#include <linux/hwmon-sysfs.h> /* * We can't determine type by probing, but if we expect pre-Linux code @@ -851,6 +854,94 @@ out: return; } +/*----------------------------------------------------------------------*/ + +#ifdef CONFIG_RTC_DRV_DS1307_HWMON + +/* + * Temperature sensor support for ds3231 devices. + */ + +#define DS3231_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 ds3231_hwmon_read_temp(struct device *dev, s16 *mC) +{ + struct ds1307 *ds1307 = dev_get_drvdata(dev); + u8 temp_buf[2]; + s16 temp; + s32 ret; + + ret = ds1307->read_block_data(ds1307->client, DS3231_REG_TEMPERATURE, + sizeof(temp_buf), temp_buf); + if (ret < 0) + return ret; + if (ret != sizeof(temp_buf)) + return -EIO; + + /* + * 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 ds3231_hwmon_show_temp(struct device *dev, + struct device_attribute *attr, char *buf) +{ + int ret; + s16 temp; + + ret = ds3231_hwmon_read_temp(dev, &temp); + if (ret) + return ret; + + return sprintf(buf, "%d\n", temp); +} +static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ds3231_hwmon_show_temp, + NULL, 0); + +static struct attribute *ds3231_hwmon_attrs[] = { + &sensor_dev_attr_temp1_input.dev_attr.attr, + NULL, +}; +ATTRIBUTE_GROUPS(ds3231_hwmon); + +static int ds1307_hwmon_register(struct ds1307 *ds1307) +{ + struct device *dev; + + if (ds1307->type != ds_3231) + return 0; + + dev = devm_hwmon_device_register_with_groups(&ds1307->client->dev, + ds1307->client->name, + ds1307, ds3231_hwmon_groups); + if (IS_ERR(dev)) { + dev_warn(&ds1307->client->dev, + "unable to register hwmon device %ld\n", PTR_ERR(dev)); + return PTR_ERR(dev); + } + + return 0; +} + +#else + +static int ds1307_hwmon_register(struct ds1307 *ds1307) +{ + return 0; +} + +#endif + static int ds1307_probe(struct i2c_client *client, const struct i2c_device_id *id) { @@ -1191,6 +1282,8 @@ read_rtc: } } + ds1307_hwmon_register(ds1307); + return 0; exit:
DS3231 has the temperature registers with a resolution of 0.25 degree celsius. This enables to get the value through hwmon. # cat /sys/class/i2c-adapter/i2c-2/2-0068/hwmon/hwmon0/temp1_input 21000 Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com> Cc: rtc-linux@googlegroups.com Cc: Jean Delvare <jdelvare@suse.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: lm-sensors@lm-sensors.org --- * v3 (all changes are suggested by Guenter Roeck) - add RTC_DRV_DS1307_HWMON config option to fix an issue when the ds1307 driver is built into the kernel but hwmon is built as module. - don't start user-initiated temperature conversion when reading temperature, just relying on internal/automatic conversions. drivers/rtc/Kconfig | 9 +++++ drivers/rtc/rtc-ds1307.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 102 insertions(+)