mpm: Add basic driver for QSFP board's retimer

2 files changed, 108 insertions, 0 deletions

diff --git a/mpm/python/usrp_mpm/chips/CMakeLists.txt b/mpm/python/usrp_mpm/chips/CMakeLists.txt
index 94b62f33d..ff4f61bdd 100644
--- a/mpm/python/usrp_mpm/chips/CMakeLists.txt
+++ b/mpm/python/usrp_mpm/chips/CMakeLists.txt
@@ -9,6 +9,7 @@ SET(USRP_MPM_CHIP_FILES
     ${CMAKE_CURRENT_SOURCE_DIR}/__init__.py
     ${CMAKE_CURRENT_SOURCE_DIR}/lmk04828.py
     ${CMAKE_CURRENT_SOURCE_DIR}/adf400x.py
+    ${CMAKE_CURRENT_SOURCE_DIR}/ds125df410.py
 )
 LIST(APPEND USRP_MPM_FILES ${USRP_MPM_CHIP_FILES})
 SET(USRP_MPM_FILES ${USRP_MPM_FILES} PARENT_SCOPE)
diff --git a/mpm/python/usrp_mpm/chips/ds125df410.py b/mpm/python/usrp_mpm/chips/ds125df410.py
new file mode 100644
index 000000000..5cea7e67a
--- /dev/null
+++ b/mpm/python/usrp_mpm/chips/ds125df410.py
@@ -0,0 +1,107 @@
+#
+# Copyright 2018 Ettus Research, a National Instruments Company
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+"""
+DS125DF410 driver class
+
+For use with TI's retimer chip
+"""
+
+import math
+from builtins import object
+from usrp_mpm.mpmlog import get_logger
+
+LINE_RATE_PRESETS = {'Ethernet': 0xF6, 'CPRI1': 0x36, 'CPRI2': 0x46}
+ALL_CHANS = range(4)
+
+
+class DS125DF410(object):
+    """
+    Driver class for DS125DF410 access.
+
+    Inputs:
+    regs_iface : regs_iface bus driver to access device
+    parent_log : logger of parent
+    """
+
+    # (deemphasis, swing)
+    DRIVER_PRESETS = {}
+
+    def __init__(self, regs_iface, parent_log=None):
+        self.log = \
+            parent_log.getChild("DS125DF410") if parent_log is not None \
+            else get_logger("DS125DF410")
+        self.regs_iface = regs_iface
+        # Set channel select register to control set
+        self.regs_iface.poke8(0xFF, 0)
+        # Probe chip ID
+        chip_id = self.regs_iface.peek8(0x01)
+        assert chip_id == 0xd1
+        self.log.debug("Probed DS125DF410 retimer")
+        for chan in ALL_CHANS:
+            self._set_chan_select(chan)
+            # Reset channel registers
+            self.regs_iface.poke8(0x00, 0x04)
+            # Enable DFE mode
+            self.regs_iface.poke8(0x1E, 0xE1)
+            self.regs_iface.poke8(0x31, 0x40)
+
+    def _rmw(self, addr, data, mask):
+        """ Read, modify, write """
+        base = self.regs_iface.peek8(addr) & ~mask
+        data = (data & mask) | base
+        self.regs_iface.poke8(addr, data)
+
+    def _set_chan_select(self, chan):
+        """
+        Channel select
+        """
+        assert chan in ALL_CHANS
+        self.regs_iface.poke8(0xFF, chan + 4)
+
+    def set_rate_preset(self, preset, channels=None):
+        """
+        Set rate preset
+        """
+        channels = channels or ALL_CHANS
+        assert preset in LINE_RATE_PRESETS.keys()
+        for chan in channels:
+            self._set_chan_select(chan)
+            self.regs_iface.poke8(0x2F, LINE_RATE_PRESETS[preset])
+
+    def set_rate(self, rate, channels=None):
+        """
+        Set rate
+        """
+        channels = channels or ALL_CHANS
+        self.log.trace("Writing custom line rate {}".format(rate))
+        ppm_val = int(math.ceil(rate*1280.0))
+        assert ppm_val <= 0x7FFF
+        for chan in channels:
+            assert chan in ALL_CHANS
+            self._set_chan_select(chan)
+            # Set VCO divider to 1
+            self.regs_iface.poke8(0x2F, 0xC6)
+            # Set frequency range detection
+            self.regs_iface.poke8(0x60, (ppm_val & 0x00FF))
+            self.regs_iface.poke8(0x62, (ppm_val & 0x00FF))
+            self.regs_iface.poke8(0x61, 0x80 | ((ppm_val >> 8) & 0x00FF))
+            self.regs_iface.poke8(0x63, 0x80 | ((ppm_val >> 8) & 0x00FF))
+            # Set VCO tolerance range to max
+            self.regs_iface.poke8(0x64, 0xFF)
+
+    def set_driver_preset(self, preset, channels=None):
+        """
+        Set driver preset
+        """
+        channels = channels or ALL_CHANS
+        assert preset in self.DRIVER_PRESETS.keys()
+        self.log.trace("Setting retimer's driver for " + preset + " preset")
+        deemphasis, swing = self.DRIVER_PRESETS[preset]
+        for chan in channels:
+            self._set_chan_select(chan)
+            self._rmw(0x15, deemphasis, 0x47)
+            self._rmw(0x2D, swing, 0x07)
+