Re: [PATCH 6/6] rtc: isl12022: add support for temperature sensor

Guenter Roeck
2022-08-30T13:13:41Z

On 8/30/22 03:01, Rasmus Villemoes wrote:
> Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
> ---
> 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>
>
> /* 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);

Please use devm_hwmon_device_register_with_info().

Thanks,
Guenter

> + 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);