mpm: Added auto-loading of dboard-specific overlays

5 files changed, 126 insertions, 2 deletions

diff --git a/mpm/python/usrp_mpm/CMakeLists.txt b/mpm/python/usrp_mpm/CMakeLists.txt
index a470f8e67..a08e3fea1 100644
--- a/mpm/python/usrp_mpm/CMakeLists.txt
+++ b/mpm/python/usrp_mpm/CMakeLists.txt
@@ -22,6 +22,7 @@ SET(USRP_MPM_FILES ${USRP_MPM_FILES})
 SET(USRP_MPM_TOP_FILES
     ${CMAKE_CURRENT_SOURCE_DIR}/__init__.py
     ${CMAKE_CURRENT_SOURCE_DIR}/discovery.py
+    ${CMAKE_CURRENT_SOURCE_DIR}/dtoverlay.py
     ${CMAKE_CURRENT_SOURCE_DIR}/mpmlog.py
     ${CMAKE_CURRENT_SOURCE_DIR}/nijesdcore.py
     ${CMAKE_CURRENT_SOURCE_DIR}/rpc_server.py
diff --git a/mpm/python/usrp_mpm/dboard_manager/base.py b/mpm/python/usrp_mpm/dboard_manager/base.py
index c7e116fc0..e16906cb4 100644
--- a/mpm/python/usrp_mpm/dboard_manager/base.py
+++ b/mpm/python/usrp_mpm/dboard_manager/base.py
@@ -38,6 +38,12 @@ class DboardManagerBase(object):
     # maps these keys to actual spidev paths. Also throws a warning/error if
     # the SPI configuration is invalid.
     spi_chipselect = {}
+    # Lists device tree overlays that need to be applied before this class can
+    # be used. List of strings. If strings contain the token {sfp}, it will be
+    # expanded to the flavour of SFP configuration is (XG, 1G, ...).
+    # Example: 'magnesium-{sfp}' could get expanded to 'eiscat-XG'.
+    # Are applied in order.
+    dt_overlays = []
 
     def __init__(self, slot_idx, **kwargs):
         self.log = get_logger('dboardManager')
diff --git a/mpm/python/usrp_mpm/dboard_manager/eiscat.py b/mpm/python/usrp_mpm/dboard_manager/eiscat.py
index 78d5d0e18..c0a5e2fb1 100644
--- a/mpm/python/usrp_mpm/dboard_manager/eiscat.py
+++ b/mpm/python/usrp_mpm/dboard_manager/eiscat.py
@@ -366,6 +366,7 @@ class EISCAT(DboardManagerBase):
         "adc1": create_spidev_iface_sane,
         "phase_dac": create_spidev_iface_phasedac,
     }
+    dt_overlays = ['eiscat-{sfp}']
 
     def __init__(self, slot_idx, **kwargs):
         super(EISCAT, self).__init__(slot_idx, **kwargs)
diff --git a/mpm/python/usrp_mpm/dtoverlay.py b/mpm/python/usrp_mpm/dtoverlay.py
new file mode 100644
index 000000000..65b350a04
--- /dev/null
+++ b/mpm/python/usrp_mpm/dtoverlay.py
@@ -0,0 +1,111 @@
+#
+# Copyright 2017 Ettus Research (National Instruments)
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+"""
+Manipulation of device tree overlays (Linux kernel)
+"""
+
+import os
+from .mpmlog import get_logger
+
+SYSFS_OVERLAY_BASE_DIR = '/sys/kernel/config/device-tree/overlays'
+OVERLAY_DEFAULT_PATH = '/lib/firmware'
+
+def get_overlay_attrs(overlay_name):
+    """
+    List those attributes that are connected to an overlay entry in a sysfs
+    node.
+    """
+    overlay_path = os.path.join(SYSFS_OVERLAY_BASE_DIR, overlay_name)
+    attrs = {}
+    for attr_name in os.listdir(overlay_path):
+        try:
+            attr_val = open(
+                os.path.join(overlay_path, attr_name), 'r'
+            ).read().strip()
+        except OSError:
+            pass
+        if len(attr_val):
+            attrs[attr_name] = attr_val
+    return attrs
+
+def list_overlays(applied_only=False):
+    """
+    List all registered kernel modules. Returns a dict of dicts:
+    {
+        '<overlay_name>': {
+            # attributes
+        },
+    }
+
+    All the attributes come from sysfs. See get_overlay_attrs().
+
+    applied_only -- Only return those overlays that are already applied.
+    """
+    return {
+        overlay_name: get_overlay_attrs(overlay_name)
+        for overlay_name in os.listdir(SYSFS_OVERLAY_BASE_DIR)
+        if not applied_only \
+            or get_overlay_attrs(overlay_name).get('status') == 'applied'
+    }
+
+def list_available_overlays(path):
+    """
+    List available overlay files (dtbo)
+    """
+    path = path or OVERLAY_DEFAULT_PATH
+    return [x.strip()[:-5] for x in os.listdir(path) if x.endswith('.dtbo')]
+
+def apply_overlay(overlay_name):
+    """
+    Applies the given overlay. Does not check if the overlay is loaded.
+    """
+    get_logger("DTO").trace("Applying overlay `{}'...".format(overlay_name))
+    # TODO don't use this script
+    os.system("overlay add {}".format(overlay_name))
+
+def apply_overlay_safe(overlay_name):
+    """
+    Only apply an overlay if it's not yet applied.
+    """
+    if overlay_name in list_overlays(applied_only=True).keys():
+        get_logger("DTO").debug(
+            "Overlay `{}' was already applied, not applying again.".format(
+                overlay_name
+            )
+        )
+    else:
+        apply_overlay(overlay_name)
+
+def rm_overlay(overlay_name):
+    """
+    Removes the given overlay. Does not check if the overlay is loaded.
+    """
+    get_logger("DTO").trace("Removing overlay `{}'...".format(overlay_name))
+    # TODO don't use this script
+    os.system("overlay rm {}".format(overlay_name))
+
+def rm_overlay_safe(overlay_name):
+    """
+    Only remove an overlay if it's already applied.
+    """
+    if overlay_name in list_overlays(applied_only=True).keys():
+        rm_overlay(overlay_name)
+    else:
+        get_logger("DTO").debug(
+            "Overlay `{}' was not loaded, not removing.".format(overlay_name)
+        )
+
diff --git a/mpm/python/usrp_mpm/periph_manager/base.py b/mpm/python/usrp_mpm/periph_manager/base.py
index 022464476..a9259f304 100644
--- a/mpm/python/usrp_mpm/periph_manager/base.py
+++ b/mpm/python/usrp_mpm/periph_manager/base.py
@@ -25,6 +25,7 @@ from ..mpmlog import get_logger
 from .udev import get_eeprom_paths
 from .udev import get_spidev_nodes
 from usrp_mpm import net
+from usrp_mpm import dtoverlay
 
 EEPROM_DEFAULT_HEADER = struct.Struct("!I I")
 
@@ -340,11 +341,15 @@ class PeriphManagerBase(object):
             if db_class is None:
                 self.log.warning("Could not identify daughterboard class for PID {:04X}!".format(db_pid))
                 continue
+            self.log.trace("Dboard requires device tree overlays: {}".format(
+                db_class.dt_overlays
+            ))
+            for overlay in db_class.dt_overlays:
+                # FIXME don't hardcode XG
+                dtoverlay.apply_overlay_safe(overlay.format(sfp="XG"))
             self.dboards.append(db_class(dboard_idx, **dboard_info))
         self.log.info("Found {} daughterboard(s).".format(len(self.dboards)))
 
-        # self.overlays = ""
-
     def _init_interfaces(self):
         """
         Initialize the list of network interfaces