This is the bitbanging SPI driver infrastructure

If you want support for a particular piece of hardware, just fill in
a few functions in spi_bitbang_master_table. That's it.
On top of this, the RayeR SPI flasher should be supportable in ~20 LOC.

Tested, trace looks OK.

Corresponding to flashrom svn r736.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Uwe Hermann <uwe@hermann-uwe.de>
diff --git a/Makefile b/Makefile
index 6efed72..df9f73d 100644
--- a/Makefile
+++ b/Makefile
@@ -68,6 +68,9 @@
 # Always enable serprog for now. Needs to be disabled on Windows.
 CONFIG_SERPROG ?= yes
 
+# Bitbanging SPI infrastructure is not used yet.
+CONFIG_BITBANG_SPI ?= no
+
 # Always enable 3Com NICs for now.
 CONFIG_NIC3COM ?= yes
 
@@ -94,6 +97,11 @@
 endif
 endif
 
+ifeq ($(CONFIG_BITBANG_SPI), yes)
+FEATURE_CFLAGS += -D'BITBANG_SPI_SUPPORT=1'
+OBJS += bitbang_spi.o
+endif
+
 ifeq ($(CONFIG_NIC3COM), yes)
 FEATURE_CFLAGS += -D'NIC3COM_SUPPORT=1'
 OBJS += nic3com.o