net: dsa: Add support for reporting switch chip temperatures

Some switches provide chip temperature data.
Add support for reporting it through the hwmon subsystem.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig
index a585fd6..5f8ac40 100644
--- a/net/dsa/Kconfig
+++ b/net/dsa/Kconfig
@@ -11,6 +11,17 @@
 
 if NET_DSA
 
+config NET_DSA_HWMON
+	bool "Distributed Switch Architecture HWMON support"
+	default y
+	depends on HWMON && !(NET_DSA=y && HWMON=m)
+	---help---
+	  Say Y if you want to expose thermal sensor data on switches supported
+	  by the Distributed Switch Architecture.
+
+	  Some of those switches contain thermal sensors. This data is available
+	  via the hwmon sysfs interface and exposes the onboard sensors.
+
 # tagging formats
 config NET_DSA_TAG_BRCM
 	bool