On 3/3/25 12:21, Svyatoslav Ryhel wrote:
To avoid duplicating sensor functionality and conversion tables, this design
allows converting an ADC IIO channel's output directly into a temperature IIO
channel. This is particularly useful for devices where hwmon isn't suitable
or where temperature data must be accessible through IIO.
One such device is, for example, the MAX17040 fuel gauge.
Signed-off-by: Svyatoslav Ryhel <clamor95@xxxxxxxxx>
---
drivers/thermal/thermal-generic-adc.c | 54 ++++++++++++++++++++++++++-
1 file changed, 53 insertions(+), 1 deletion(-)
diff --git a/drivers/thermal/thermal-generic-adc.c b/drivers/thermal/thermal-generic-adc.c
index ee3d0aa31406..a8f3b965b39b 100644
--- a/drivers/thermal/thermal-generic-adc.c
+++ b/drivers/thermal/thermal-generic-adc.c
@@ -7,6 +7,7 @@
* Author: Laxman Dewangan <ldewangan@xxxxxxxxxx>
*/
#include <linux/iio/consumer.h>
+#include <linux/iio/iio.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
@@ -73,6 +74,57 @@ static const struct thermal_zone_device_ops gadc_thermal_ops = {
.get_temp = gadc_thermal_get_temp,
};
+static const struct iio_chan_spec gadc_thermal_iio_channel[] = {
+ {
+ .type = IIO_TEMP,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
I would add the IIO_CHAN_INFO_SCALE and say it's in milli-degrees.
+ }
+};
+
+static int gadc_thermal_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *temp, int *val2, long mask)
+{
+ struct gadc_thermal_info *gtinfo = iio_priv(indio_dev);
+ int ret;
+
+ if (mask != IIO_CHAN_INFO_PROCESSED)
+ return -EINVAL;
Therefore, here it would need to handle such case as well, when
a client is asking about scale.
+
+ ret = gadc_thermal_get_temp(gtinfo->tz_dev, temp);
+ if (ret < 0)
+ return ret;
+
+ *temp /= 1000;
IMO we shouldn't cut the precision if it's provided.
The user of this would know what to do with the value (when
the proper information about scale is also available).
+
+ return IIO_VAL_INT;
+}
+
+static const struct iio_info gadc_thermal_iio_info = {
+ .read_raw = gadc_thermal_read_raw,
+};
+
+static int gadc_iio_register(struct device *dev, struct gadc_thermal_info *gti)
+{
+ struct gadc_thermal_info *gtinfo;
+ struct iio_dev *indio_dev;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(struct gadc_thermal_info));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ gtinfo = iio_priv(indio_dev);
+ memcpy(gtinfo, gti, sizeof(struct gadc_thermal_info));
+
+ indio_dev->name = dev_name(dev);
+ indio_dev->info = &gadc_thermal_iio_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = gadc_thermal_iio_channel;
+ indio_dev->num_channels = ARRAY_SIZE(gadc_thermal_iio_channel);
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+
static int gadc_thermal_read_linear_lookup_table(struct device *dev,
struct gadc_thermal_info *gti)
{
@@ -153,7 +205,7 @@ static int gadc_thermal_probe(struct platform_device *pdev)
devm_thermal_add_hwmon_sysfs(dev, gti->tz_dev);
- return 0;
+ return gadc_iio_register(&pdev->dev, gti);
}
static const struct of_device_id of_adc_thermal_match[] = {
