[PATCH v2] ARM: dts: vfxxx: Add iio_hwmon node for ADC temperature channel

[Sanchayan Maity <maitysanchayan@gmail.com>]

Add iio_hwmon node to expose the temperature channel on Vybrid as
hardware monitor device using the iio_hwmon driver.

Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>
---

Hello,

The first version of the patch was send quite a while ago.
https://lkml.org/lkml/2015/9/16/932

Shawn you had requested that hyphen rather than underscore should
be used in node name. I looked into that.

The iio_hwmon driver calls hwmon_device register_with_groups inside
hwmon.c and this
http://lxr.free-electrons.com/source/drivers/hwmon/hwmon.c#L103

does not allow hyphen in hwmon name attribute. I was not aware of
this but while trying to test the change, the device probe failed
with EINVAL. I think we should stick to the existing use of the
bindings or we need to change the hwmon code as well along with the
existing device tree files and binding documentation.

Changes since v1:
1. Expose ADC1 temperature channel as well
2. Move the entry outside of the aips1 bus node

Best Regards,
Sanchayan Maity.
---
 arch/arm/boot/dts/vfxxx.dtsi | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm/boot/dts/vfxxx.dtsi b/arch/arm/boot/dts/vfxxx.dtsi
index a5f07e3..8ed8e47 100644
--- a/arch/arm/boot/dts/vfxxx.dtsi
+++ b/arch/arm/boot/dts/vfxxx.dtsi
@@ -673,5 +673,10 @@
 				status = "disabled";
 			};
 		};
+
+		iio_hwmon {
+			compatible = "iio-hwmon";
+			io-channels = <&adc0 16>, <&adc1 16>;
+		};
 	};
 };
-- 
2.7.1