mac80211: ath9k: enable adding wireless noise to kernel entropy pool

This option allows adding the ath9k ADC register output as a source
of randomness into the Linux entropy pool at sufficient quality
random data (at least 10 bits and up to 22 bits of min-entropy for
a 32-bit value).

Fixes FS#1444
Signed-off-by: Alan Swanson <reiver@improbability.net>

package/kernel/mac80211/ath.mk

@@ -7,6 +7,7 @@ PKG_CONFIG_DEPENDS += \
 	CONFIG_PACKAGE_ATH_DFS \
 	CONFIG_PACKAGE_ATH_SPECTRAL \
 	CONFIG_PACKAGE_ATH_DYNACK \
+	CONFIG_ATH9K_HWRNG \
 	CONFIG_ATH9K_SUPPORT_PCOEM \
 	CONFIG_ATH9K_TX99 \
 	CONFIG_ATH10K_LEDS \
@@ -44,6 +45,7 @@ config-$(CONFIG_TARGET_ath79) += ATH9K_AHB
 config-$(CONFIG_TARGET_ipq40xx) += ATH10K_AHB
 config-$(CONFIG_PCI) += ATH9K_PCI
 config-$(CONFIG_ATH_USER_REGD) += ATH_USER_REGD
+config-$(CONFIG_ATH9K_HWRNG) += ATH9K_HWRNG
 config-$(CONFIG_ATH9K_SUPPORT_PCOEM) += ATH9K_PCOEM
 config-$(CONFIG_ATH9K_TX99) += ATH9K_TX99
 config-$(CONFIG_ATH9K_UBNTHSR) += ATH9K_UBNTHSR
@@ -207,6 +209,12 @@ endef
 
 define KernelPackage/ath9k/config
 
+	config ATH9K_HWRNG
+		bool "Add wireless noise as source of randomness to kernel entropy pool"
+		depends on PACKAGE_kmod-ath9k
+		select PACKAGE_kmod-random-core
+		default n
+
 	config ATH9K_SUPPORT_PCOEM
 		bool "Support chips used in PC OEM cards"
 		depends on PACKAGE_kmod-ath9k