diff --git a/artiq/gateware/rtio/phy/ttl_serdes_7series.py b/artiq/gateware/rtio/phy/ttl_serdes_7series.py
index e1d5278f5..266037e1e 100644
--- a/artiq/gateware/rtio/phy/ttl_serdes_7series.py
+++ b/artiq/gateware/rtio/phy/ttl_serdes_7series.py
@@ -101,15 +101,15 @@ class Output_8X(ttl_serdes_generic.Output):
         ttl_serdes_generic.Output.__init__(self, serdes)
 
 
-class Inout_8X(ttl_serdes_generic.Inout):
+class InOut_8X(ttl_serdes_generic.InOut):
     def __init__(self, pad, pad_n=None):
         serdes = _IOSERDESE2_8X(pad, pad_n)
         self.submodules += serdes
-        ttl_serdes_generic.Inout.__init__(self, serdes)
+        ttl_serdes_generic.InOut.__init__(self, serdes)
 
 
-class Input_8X(ttl_serdes_generic.Inout):
+class Input_8X(ttl_serdes_generic.InOut):
     def __init__(self, pad, pad_n=None):
         serdes = _ISERDESE2_8X(pad, pad_n)
         self.submodules += serdes
-        ttl_serdes_generic.Inout.__init__(self, serdes)
+        ttl_serdes_generic.InOut.__init__(self, serdes)
diff --git a/artiq/gateware/rtio/phy/ttl_serdes_generic.py b/artiq/gateware/rtio/phy/ttl_serdes_generic.py
index 06bf186fc..0d88c4284 100644
--- a/artiq/gateware/rtio/phy/ttl_serdes_generic.py
+++ b/artiq/gateware/rtio/phy/ttl_serdes_generic.py
@@ -54,7 +54,7 @@ class Output(Module):
             override_en, override_o)
 
 
-class Inout(Module):
+class InOut(Module):
     def __init__(self, serdes):
         serdes_width = len(serdes.o)
         assert len(serdes.i) == serdes_width
@@ -150,10 +150,10 @@ class _OutputTB(Module):
             yield
 
 
-class _InoutTB(Module):
+class _InOutTB(Module):
     def __init__(self):
         self.serdes = _FakeSerdes()
-        self.submodules.dut = RenameClockDomains(Inout(self.serdes),
+        self.submodules.dut = RenameClockDomains(InOut(self.serdes),
                                                  {"rio_phy": "sys",
                                                   "rio": "sys"})
 
@@ -273,7 +273,7 @@ if __name__ == "__main__":
 
     cls = {
         "output": _OutputTB,
-        "inout": _InoutTB
+        "inout": _InOutTB
     }[sys.argv[1]]
 
     with Simulator(cls(), TopLevel("top.vcd", clk_period=int(1/0.125))) as s:
diff --git a/artiq/gateware/rtio/phy/ttl_serdes_spartan6.py b/artiq/gateware/rtio/phy/ttl_serdes_spartan6.py
index bf851a662..1a772f3f8 100644
--- a/artiq/gateware/rtio/phy/ttl_serdes_spartan6.py
+++ b/artiq/gateware/rtio/phy/ttl_serdes_spartan6.py
@@ -84,11 +84,11 @@ class Output_8X(ttl_serdes_generic.Output):
         ttl_serdes_generic.Output.__init__(self, serdes)
 
 
-class Inout_8X(ttl_serdes_generic.Inout):
+class InOut_8X(ttl_serdes_generic.InOut):
     def __init__(self, pad, stb):
         serdes = _IOSERDES2_8X(pad, stb)
         self.submodules += serdes
-        ttl_serdes_generic.Inout.__init__(self, serdes)
+        ttl_serdes_generic.InOut.__init__(self, serdes)
 
 
 class _OSERDES2_4X(Module):
@@ -149,8 +149,8 @@ class Output_4X(ttl_serdes_generic.Output):
         ttl_serdes_generic.Output.__init__(self, serdes)
 
 
-class Inout_4X(ttl_serdes_generic.Inout):
+class InOut_4X(ttl_serdes_generic.InOut):
     def __init__(self, pad, stb):
         serdes = _IOSERDES2_4X(pad, stb)
         self.submodules += serdes
-        ttl_serdes_generic.Inout.__init__(self, serdes)
+        ttl_serdes_generic.InOut.__init__(self, serdes)
diff --git a/artiq/gateware/rtio/phy/ttl_simple.py b/artiq/gateware/rtio/phy/ttl_simple.py
index 85c03af6d..d5129606a 100644
--- a/artiq/gateware/rtio/phy/ttl_simple.py
+++ b/artiq/gateware/rtio/phy/ttl_simple.py
@@ -64,7 +64,7 @@ class Input(Module):
         self.probes += [i]
 
 
-class Inout(Module):
+class InOut(Module):
     def __init__(self, pad):
         self.rtlink = rtlink.Interface(
             rtlink.OInterface(2, 2),
diff --git a/artiq/gateware/targets/kc705_dds.py b/artiq/gateware/targets/kc705_dds.py
index f154daaee..4ecb108e1 100755
--- a/artiq/gateware/targets/kc705_dds.py
+++ b/artiq/gateware/targets/kc705_dds.py
@@ -177,7 +177,7 @@ class NIST_CLOCK(_NIST_Ions):
         rtio_channels = []
         for i in range(16):
             if i % 4 == 3:
-                phy = ttl_serdes_7series.Inout_8X(platform.request("ttl", i))
+                phy = ttl_serdes_7series.InOut_8X(platform.request("ttl", i))
                 self.submodules += phy
                 rtio_channels.append(rtio.Channel.from_phy(phy, ififo_depth=512))
             else:
@@ -186,11 +186,11 @@ class NIST_CLOCK(_NIST_Ions):
                 rtio_channels.append(rtio.Channel.from_phy(phy))
 
         for i in range(2):
-            phy = ttl_serdes_7series.Inout_8X(platform.request("pmt", i))
+            phy = ttl_serdes_7series.InOut_8X(platform.request("pmt", i))
             self.submodules += phy
             rtio_channels.append(rtio.Channel.from_phy(phy, ififo_depth=512))
 
-        phy = ttl_serdes_7series.Inout_8X(platform.request("user_sma_gpio_n_33"))
+        phy = ttl_serdes_7series.InOut_8X(platform.request("user_sma_gpio_n_33"))
         self.submodules += phy
         rtio_channels.append(rtio.Channel.from_phy(phy, ififo_depth=512))
 
@@ -247,7 +247,7 @@ class NIST_QC2(_NIST_Ions):
 
         # All TTL channels are In+Out capable
         for i in range(40):
-            phy = ttl_serdes_7series.Inout_8X(
+            phy = ttl_serdes_7series.InOut_8X(
                 platform.request("ttl", i))
             self.submodules += phy
             rtio_channels.append(rtio.Channel.from_phy(phy, ififo_depth=512))
@@ -260,7 +260,7 @@ class NIST_QC2(_NIST_Ions):
             clock_generators.append(rtio.Channel.from_phy(phy))
 
         # user SMA on KC705 board
-        phy = ttl_serdes_7series.Inout_8X(platform.request("user_sma_gpio_n_33"))
+        phy = ttl_serdes_7series.InOut_8X(platform.request("user_sma_gpio_n_33"))
         self.submodules += phy
         rtio_channels.append(rtio.Channel.from_phy(phy, ififo_depth=512))
 
diff --git a/artiq/gateware/targets/kc705_drtio_master.py b/artiq/gateware/targets/kc705_drtio_master.py
index 9e16ead4e..150676460 100755
--- a/artiq/gateware/targets/kc705_drtio_master.py
+++ b/artiq/gateware/targets/kc705_drtio_master.py
@@ -96,7 +96,7 @@ class Master(MiniSoC, AMPSoC):
             self.submodules += phy
             rtio_channels.append(rtio.Channel.from_phy(phy))
         for sma in "user_sma_gpio_p", "user_sma_gpio_n":
-            phy = ttl_simple.Inout(platform.request(sma))
+            phy = ttl_simple.InOut(platform.request(sma))
             self.submodules += phy
             rtio_channels.append(rtio.Channel.from_phy(phy))
 
diff --git a/artiq/gateware/targets/kc705_drtio_satellite.py b/artiq/gateware/targets/kc705_drtio_satellite.py
index b7c26f68f..59b3d1940 100755
--- a/artiq/gateware/targets/kc705_drtio_satellite.py
+++ b/artiq/gateware/targets/kc705_drtio_satellite.py
@@ -40,7 +40,7 @@ class Satellite(BaseSoC):
             self.submodules += phy
             rtio_channels.append(rtio.Channel.from_phy(phy))
         for sma in "user_sma_gpio_p", "user_sma_gpio_n":
-            phy = ttl_simple.Inout(platform.request(sma))
+            phy = ttl_simple.InOut(platform.request(sma))
             self.submodules += phy
             rtio_channels.append(rtio.Channel.from_phy(phy))
 
diff --git a/artiq/gateware/targets/phaser.py b/artiq/gateware/targets/phaser.py
index e897d82e4..56d6fdaa5 100755
--- a/artiq/gateware/targets/phaser.py
+++ b/artiq/gateware/targets/phaser.py
@@ -203,7 +203,7 @@ class Phaser(MiniSoC, AMPSoC):
 
         rtio_channels = []
 
-        phy = ttl_serdes_7series.Inout_8X(
+        phy = ttl_serdes_7series.InOut_8X(
             platform.request("user_sma_gpio_n"))
         self.submodules += phy
         rtio_channels.append(rtio.Channel.from_phy(phy, ififo_depth=128))
diff --git a/artiq/gateware/targets/pipistrello.py b/artiq/gateware/targets/pipistrello.py
index 8f3d80a28..86721bd20 100755
--- a/artiq/gateware/targets/pipistrello.py
+++ b/artiq/gateware/targets/pipistrello.py
@@ -182,7 +182,7 @@ trce -v 12 -fastpaths -tsi {build_name}.tsi -o {build_name}.twr {build_name}.ncd
         # the last TTL is used for ClockGen
         for i in range(15):
             if i in (0, 1):
-                phy = ttl_serdes_spartan6.Inout_4X(platform.request("ttl", i),
+                phy = ttl_serdes_spartan6.InOut_4X(platform.request("ttl", i),
                                                    self.rtio_crg.rtiox4_stb)
             elif i in (2,):
                 phy = ttl_serdes_spartan6.Output_8X(platform.request("ttl", i),