ls2: avoid using DRIVE attribute on Xilinx devices for now

The DRIVE attribute is currently broken.
See: https://github.com/openXC7/nextpnr-xilinx/issues/7

diff --git a/src/ls2.py b/src/ls2.py
index 2a17fae2771b15152c36f37229d4e3b24856a0a4..f151cb44c88d89fd2db5a7b8acb26c0995fd5a9f 100644 (file)
--- a/src/ls2.py
+++ b/src/ls2.py
@@ -968,7 +968,11 @@ def build_platform(fpga, firmware):
                      Subsignal("dq3",  Pins("M14", dir="io")),
                      Subsignal("cs_n", Pins("L13", dir="o")),
                      Subsignal("clk",  Pins("L16", dir="o")),
-                     Attrs(PULLMODE="NONE", DRIVE="4", IOSTANDARD="LVCMOS33"))
+                     # drive support is currently broken on
+                     # nextpnx-xilinx/openxc7. Add back DRIVE="4" below
+                     # when upstream fixes it.
+                     # See: https://github.com/openXC7/nextpnr-xilinx/issues/7
+                     Attrs(PULLMODE="NONE", IOSTANDARD="LVCMOS33"))
         ]
         platform.add_resources(spi_0_ios)
         spi_0_pins = platform.request("spi_0", 0)