Add serial port bitbanging code

This adds the pony_spi driver which supports the SI_Prog adapter, which
is commonly used for SPI chips with PonyProg 2000, and a custom adapter
called "SERBANG" which differs in the logic of two pins.

Corresponding to flashrom svn r1525.

Signed-off-by: Virgil-Adrian Teaca <darkstarlinux@gmail.com>
Acked-by: Michael Karcher <flashrom@mkarcher.dialup.fu-berlin.de>
diff --git a/Makefile b/Makefile
index 352ca29..d98a594 100644
--- a/Makefile
+++ b/Makefile
@@ -292,6 +292,9 @@
 # RayeR SPIPGM hardware support
 CONFIG_RAYER_SPI ?= yes
 
+# PonyProg2000 SPI hardware support
+CONFIG_PONY_SPI ?= yes
+
 # Always enable 3Com NICs for now.
 CONFIG_NIC3COM ?= yes
 
@@ -348,6 +351,9 @@
 ifeq ($(CONFIG_RAYER_SPI), yes)
 override CONFIG_BITBANG_SPI = yes
 else
+ifeq ($(CONFIG_PONY_SPI), yes)
+override CONFIG_BITBANG_SPI = yes
+else
 ifeq ($(CONFIG_INTERNAL), yes)
 override CONFIG_BITBANG_SPI = yes
 else
@@ -362,6 +368,7 @@
 endif
 endif
 endif
+endif
 
 ifeq ($(CONFIG_INTERNAL), yes)
 FEATURE_CFLAGS += -D'CONFIG_INTERNAL=1'
@@ -388,6 +395,12 @@
 NEED_PCI := yes
 endif
 
+ifeq ($(CONFIG_PONY_SPI), yes)
+FEATURE_CFLAGS += -D'CONFIG_PONY_SPI=1'
+PROGRAMMER_OBJS += pony_spi.o
+NEED_SERIAL := yes
+endif
+
 ifeq ($(CONFIG_BITBANG_SPI), yes)
 FEATURE_CFLAGS += -D'CONFIG_BITBANG_SPI=1'
 PROGRAMMER_OBJS += bitbang_spi.o