Added sketch of bit-bashing interface common code

1 files changed, 55 insertions, 0 deletions

diff --git a/src/drivers/bitbash/bitbash.c b/src/drivers/bitbash/bitbash.c
new file mode 100644
index 00000000..270c1b92
--- /dev/null
+++ b/src/drivers/bitbash/bitbash.c
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <timer.h>
+#include <gpxe/bitbash.h>
+
+/** @file
+ *
+ * Bit-bashing interfaces
+ *
+ */
+
+/**
+ * Set/clear output bit
+ *
+ * @v basher		Bit-bashing interface
+ * @v bit_id		Bit number
+ * @v data		Value to write
+ * 
+ * If @c data is 0, a logic 0 will be written.  If @c data is
+ * non-zero, a logic 1 will be written.
+ */
+void write_bit ( struct bit_basher *basher, unsigned int bit_id,
+		 unsigned long data ) {
+	basher->write ( basher, bit_id, ( data ? -1UL : 0 ) );
+	udelay ( basher->udelay );
+}
+
+/**
+ * Read input bit
+ *
+ * @v basher		Bit-bashing interface
+ * @v bit_id		Bit number
+ * @ret data		Value read
+ *
+ * @c data will always be either 0 or 1.
+ */
+int read_bit ( struct bit_basher *basher, unsigned int bit_id ) {
+	return ( basher->read ( basher, bit_id ) ? 1 : 0 );
+}