Factor out "sd_card_{1bit,4bit,spi}" resources.

diff --git a/nmigen_boards/dev/sd.py b/nmigen_boards/dev/sd.py
new file mode 100644 (file)
index 0000000..8fdbcbe
--- /dev/null
+++ b/nmigen_boards/dev/sd.py
@@ -0,0 +1,46 @@
+from nmigen.build import *
+
+
+__all__ = ["SDCardResources"]
+
+
+def SDCardResources(*args, clk, cmd, dat0, dat1=None, dat2=None, dat3=None,
+                    cd=None, wp=None, attrs=None):
+    resources = []
+
+    io_common = []
+    if attrs is not None:
+        io_common.append(attrs)
+    if cd is not None:
+        io_common.append(Subsignal("cd", Pins(cd, dir="i", assert_width=1)))
+    if wp is not None:
+        io_common.append(Subsignal("wp", PinsN(wp, dir="i", assert_width=1)))
+
+    io_native = list(io_common)
+    io_native.append(Subsignal("clk", Pins(clk, dir="o", assert_width=1)))
+    io_native.append(Subsignal("cmd", Pins(cmd, dir="o", assert_width=1)))
+
+    io_1bit = list(io_native)
+    io_1bit.append(Subsignal("dat", Pins(dat0, dir="io", assert_width=1)))
+    if dat3 is not None: # works as electronic card detect
+        io_1bit.append(Subsignal("ecd", Pins(dat3, dir="i", assert_width=1)))
+    resources.append(Resource.family(*args, default_name="sd_card", ios=io_1bit,
+                                     name_suffix="1bit"))
+
+    if dat1 is not None and dat2 is not None and dat3 is not None:
+        io_4bit = list(io_native)
+        io_4bit.append(Subsignal("dat", Pins(" ".join((dat0, dat1, dat2, dat3)), dir="io",
+                                             assert_width=4)))
+        resources.append(Resource.family(*args, default_name="sd_card", ios=io_4bit,
+                                         name_suffix="4bit"))
+
+    if dat3 is not None:
+        io_spi = list(io_common)
+        io_spi.append(Subsignal("cs", PinsN(dat3, dir="io"))) # doubles as electronic card detect
+        io_spi.append(Subsignal("clk", Pins(clk, dir="o", assert_width=1)))
+        io_spi.append(Subsignal("mosi", Pins(cmd, dir="o", assert_width=1)))
+        io_spi.append(Subsignal("miso", Pins(dat0, dir="i", assert_width=1)))
+        resources.append(Resource.family(*args, default_name="sd_card", ios=io_spi,
+                                         name_suffix="spi"))
+
+    return resources