cmake: Add ENABLE_N300 target

Driver support for N310/N300 was previously implied by
ENABLE_MPMD, which had two issues:
1) It was not clear that ENABLE_MPMD was actually enabling
   the N3x0
2) It did not allow to enable mpmd support without N3x0 support

This resolves these issues.

3 files changed, 27 insertions, 21 deletions

diff --git a/host/lib/usrp/dboard/CMakeLists.txt b/host/lib/usrp/dboard/CMakeLists.txt
index 6bca04290..83bb0a96c 100644
--- a/host/lib/usrp/dboard/CMakeLists.txt
+++ b/host/lib/usrp/dboard/CMakeLists.txt
@@ -46,5 +46,9 @@ IF(ENABLE_X300)
     )
 ENDIF(ENABLE_X300)
 
-INCLUDE_SUBDIRECTORY(magnesium)
-INCLUDE_SUBDIRECTORY(eiscat)
+IF(ENABLE_N300)
+    INCLUDE_SUBDIRECTORY(magnesium)
+ENDIF(ENABLE_N300)
+IF(ENABLE_MPMD AND ENABLE_EISCAT)
+    INCLUDE_SUBDIRECTORY(eiscat)
+ENDIF(ENABLE_MPMD AND ENABLE_EISCAT)
diff --git a/host/lib/usrp/dboard/eiscat/CMakeLists.txt b/host/lib/usrp/dboard/eiscat/CMakeLists.txt
index 156e139fb..13da2d6da 100644
--- a/host/lib/usrp/dboard/eiscat/CMakeLists.txt
+++ b/host/lib/usrp/dboard/eiscat/CMakeLists.txt
@@ -4,10 +4,11 @@
 # SPDX-License-Identifier: GPL-3.0
 #
 
-IF(ENABLE_MPMD AND ENABLE_EISCAT)
-    LIST(APPEND EISCAT_SOURCES
-        ${CMAKE_CURRENT_SOURCE_DIR}/eiscat_radio_ctrl_impl.cpp
-    )
-    LIBUHD_APPEND_SOURCES(${EISCAT_SOURCES})
-ENDIF(ENABLE_MPMD AND ENABLE_EISCAT)
+# This file is conditionally included if ENABLE_MPMD and ENABLE_EISCAT are
+# set to true.
+
+LIST(APPEND EISCAT_SOURCES
+    ${CMAKE_CURRENT_SOURCE_DIR}/eiscat_radio_ctrl_impl.cpp
+)
+LIBUHD_APPEND_SOURCES(${EISCAT_SOURCES})
 
diff --git a/host/lib/usrp/dboard/magnesium/CMakeLists.txt b/host/lib/usrp/dboard/magnesium/CMakeLists.txt
index eca9e5234..417cd4f54 100644
--- a/host/lib/usrp/dboard/magnesium/CMakeLists.txt
+++ b/host/lib/usrp/dboard/magnesium/CMakeLists.txt
@@ -4,17 +4,18 @@
 # SPDX-License-Identifier: GPL-3.0
 #
 
-IF(ENABLE_MPMD)
-    LIST(APPEND MAGNESIUM_SOURCES
-        ${CMAKE_CURRENT_SOURCE_DIR}/magnesium_radio_ctrl_impl.cpp
-        ${CMAKE_CURRENT_SOURCE_DIR}/magnesium_radio_ctrl_init.cpp
-        ${CMAKE_CURRENT_SOURCE_DIR}/magnesium_radio_ctrl_cpld.cpp
-        ${CMAKE_CURRENT_SOURCE_DIR}/magnesium_radio_ctrl_gain.cpp
-        ${CMAKE_CURRENT_SOURCE_DIR}/magnesium_ad9371_iface.cpp
-        ${CMAKE_CURRENT_SOURCE_DIR}/magnesium_bands.cpp
-        ${CMAKE_CURRENT_SOURCE_DIR}/magnesium_cpld_ctrl.cpp
-        ${CMAKE_CURRENT_SOURCE_DIR}/magnesium_gain_table.cpp
-    )
-    LIBUHD_APPEND_SOURCES(${MAGNESIUM_SOURCES})
-ENDIF(ENABLE_MPMD)
+# This file is conditionally included if ENABLE_MPMD and ENABLE_N300 are
+# set to true.
+
+LIST(APPEND MAGNESIUM_SOURCES
+    ${CMAKE_CURRENT_SOURCE_DIR}/magnesium_radio_ctrl_impl.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/magnesium_radio_ctrl_init.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/magnesium_radio_ctrl_cpld.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/magnesium_radio_ctrl_gain.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/magnesium_ad9371_iface.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/magnesium_bands.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/magnesium_cpld_ctrl.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/magnesium_gain_table.cpp
+)
+LIBUHD_APPEND_SOURCES(${MAGNESIUM_SOURCES})