[PATCH 3.14 14/64] hwmon: (ntc_thermistor) Ensure iio channel is of type IIO_VOLTAGE

Greg Kroah-Hartman
2015-06-03T12:10:24Z

From: Chris Lesiak <chris.lesiak@licor.com>

commit adba657533bdd255f7b78bc8a324091f46b294cd upstream.

When configured via device tree, the associated iio device needs to be
measuring voltage for the conversion to resistance to be correct.
Return -EINVAL if that is not the case.

Signed-off-by: Chris Lesiak <chris.lesiak@licor.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/hwmon/ntc_thermistor.c | 9 +++++++++
1 file changed, 9 insertions(+)

--- a/drivers/hwmon/ntc_thermistor.c
+++ b/drivers/hwmon/ntc_thermistor.c
@@ -181,8 +181,10 @@ static struct ntc_thermistor_platform_da
ntc_thermistor_parse_dt(struct platform_device *pdev)
{
struct iio_channel *chan;
+ enum iio_chan_type type;
struct device_node *np = pdev->dev.of_node;
struct ntc_thermistor_platform_data *pdata;
+ int ret;

if (!np)
return NULL;
@@ -195,6 +197,13 @@ ntc_thermistor_parse_dt(struct platform_
if (IS_ERR(chan))
return ERR_CAST(chan);

+ ret = iio_get_channel_type(chan, &type);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ if (type != IIO_VOLTAGE)
+ return ERR_PTR(-EINVAL);
+
if (of_property_read_u32(np, "pullup-uv", &pdata->pullup_uv))
return ERR_PTR(-ENODEV);
if (of_property_read_u32(np, "pullup-ohm", &pdata->pullup_ohm))