On 30/08/2022 12:01:52+0200, Rasmus Villemoes wrote: > Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> > --- > drivers/rtc/rtc-isl12022.c | 81 ++++++++++++++++++++++++++++++++++++++ > 1 file changed, 81 insertions(+) > > diff --git a/drivers/rtc/rtc-isl12022.c b/drivers/rtc/rtc-isl12022.c > index b295ec92ee17..1bd72f436318 100644 > --- a/drivers/rtc/rtc-isl12022.c > +++ b/drivers/rtc/rtc-isl12022.c > @@ -17,6 +17,8 @@ > #include <linux/of.h> > #include <linux/of_device.h> > #include <linux/regmap.h> > +#include <linux/hwmon.h> > +#include <linux/hwmon-sysfs.h> You should keep that list ordered > > /* ISL register offsets */ > #define ISL12022_REG_SC 0x00 > @@ -30,6 +32,9 @@ > #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 */ > > @@ -38,6 +43,7 @@ > > #define ISL12022_INT_WRTC (1 << 6) > > +#define ISL12022_BETA_TSE (1 << 7) > > static struct i2c_driver isl12022_driver; > > @@ -48,6 +54,79 @@ struct isl12022 { > bool write_enabled; /* true if write enable is set */ > }; > > +/* > + * 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, s32 *mC) > +{ > + struct isl12022 *isl12022 = dev_get_drvdata(dev); > + struct regmap *regmap = isl12022->regmap; > + u8 temp_buf[2]; > + s32 temp; > + int 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 ssize_t > +isl12022_hwmon_show_temp(struct device *dev, struct device_attribute *attr, char *buf) > +{ > + int ret; > + s32 temp; > + > + ret = isl12022_hwmon_read_temp(dev, &temp); > + if (ret) > + return ret; > + > + return sprintf(buf, "%d\n", temp); > +} > +static SENSOR_DEVICE_ATTR(temp1_input, 0444, isl12022_hwmon_show_temp, > + NULL, 0); > + > +static struct attribute *isl12022_hwmon_attrs[] = { > + &sensor_dev_attr_temp1_input.dev_attr.attr, > + NULL, > +}; > +ATTRIBUTE_GROUPS(isl12022_hwmon); > + > +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_groups(dev, "isl12022", isl12022, > + isl12022_hwmon_groups); > + 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. > @@ -179,6 +258,8 @@ static int isl12022_probe(struct i2c_client *client) > 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); > -- > 2.37.2 > -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com