trellis: Add option to select SPI mode.

This allows a significant speedup when booting large bitstreams on ECP5
boards that support dual or quad SPI operation.

litex/build/lattice/trellis.py

@@ -118,10 +118,10 @@ _build_template = [
     "yosys -l {build_name}.rpt {build_name}.ys",
     "nextpnr-ecp5 --json {build_name}.json --lpf {build_name}.lpf --textcfg {build_name}.config  \
     --{architecture} --package {package} --speed {speed_grade} {timefailarg} {ignoreloops} --seed {seed}",
-    "ecppack {build_name}.config --svf {build_name}.svf --bit {build_name}.bit --bootaddr {bootaddr}"
+    "ecppack {build_name}.config --svf {build_name}.svf --bit {build_name}.bit --bootaddr {bootaddr} --spimode {spimode}"
 ]
 
-def _build_script(source, build_template, build_name, architecture, package, speed_grade, timingstrict, ignoreloops, bootaddr, seed):
+def _build_script(source, build_template, build_name, architecture, package, speed_grade, timingstrict, ignoreloops, bootaddr, seed, spimode):
     if sys.platform in ("win32", "cygwin"):
         script_ext = ".bat"
         script_contents = "@echo off\nrem Autogenerated by LiteX / git: " + tools.get_litex_git_revision() + "\n\n"
@@ -142,7 +142,8 @@ def _build_script(source, build_template, build_name, architecture, package, spe
             ignoreloops     = "--ignore-loops" if ignoreloops else "",
             bootaddr        = bootaddr,
             fail_stmt       = fail_stmt,
-            seed            = seed)
+            seed            = seed,
+            spimode         = spimode)
 
     script_file = "build_" + build_name + script_ext
     tools.write_to_file(script_file, script_contents, force_unix=False)
@@ -190,6 +191,7 @@ class LatticeTrellisToolchain:
         ignoreloops    = False,
         bootaddr       = 0,
         seed           = 1,
+        spimode        = "fast-read",
         **kwargs):
 
         # Create build directory
@@ -221,7 +223,7 @@ class LatticeTrellisToolchain:
 
         # Generate build script
         script = _build_script(False, self.build_template, build_name, architecture, package,
-                               speed_grade, timingstrict, ignoreloops, bootaddr, seed)
+                               speed_grade, timingstrict, ignoreloops, bootaddr, seed, spimode)
         # Run
         if run:
             _run_script(script)
@@ -249,6 +251,8 @@ def trellis_args(parser):
                         help="ignore combinational loops in timing analysis, i.e. pass '--ignore-loops' to nextpnr")
     parser.add_argument("--ecppack-bootaddr", default=0,
                         help="Set boot address for next image, i.e. pass '--bootaddr xxx' to ecppack")
+    parser.add_argument("--ecppack-spimode", default="fast-read",
+                        help="Set slave SPI programming mode")
     parser.add_argument("--nextpnr-seed", default=1, type=int,
                         help="seed to pass to nextpnr")
 
@@ -258,5 +262,6 @@ def trellis_argdict(args):
         "timingstrict": args.nextpnr_timingstrict,
         "ignoreloops":  args.nextpnr_ignoreloops,
         "bootaddr":     args.ecppack_bootaddr,
+        "spimode":      args.ecppack_spimdoe,
         "seed":         args.nextpnr_seed,
     }