[3.19.y-ckt stable] Patch "hwmon: (ntc_thermistor) Ensure iio channel is of type IIO_VOLTAGE" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    hwmon: (ntc_thermistor) Ensure iio channel is of type IIO_VOLTAGE

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt3.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 78fc2b3b7865b6d8b7e08d1b39ed4ecb4543d73b Mon Sep 17 00:00:00 2001
From: Chris Lesiak <chris.lesiak at licor.com>
Date: Tue, 26 May 2015 15:40:44 -0500
Subject: hwmon: (ntc_thermistor) Ensure iio channel is of type IIO_VOLTAGE

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 at licor.com>
Signed-off-by: Guenter Roeck <linux at roeck-us.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/hwmon/ntc_thermistor.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/hwmon/ntc_thermistor.c b/drivers/hwmon/ntc_thermistor.c
index 112e4d4..6880011 100644
--- a/drivers/hwmon/ntc_thermistor.c
+++ b/drivers/hwmon/ntc_thermistor.c
@@ -239,8 +239,10 @@ static struct ntc_thermistor_platform_data *
 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;
@@ -253,6 +255,13 @@ ntc_thermistor_parse_dt(struct platform_device *pdev)
 	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))
--
1.9.1