From 9f4f1d0b6ba917519e4a559298c62061cb422943 Mon Sep 17 00:00:00 2001
From: Jared Boone <jboone@earfeast.com>
Date: Tue, 31 Jul 2012 22:07:08 -0700
Subject: [PATCH] Bitband library, factored out of other code.

---
 firmware/common/bitband.c | 45 +++++++++++++++++++++++++++++++++++++++
 firmware/common/bitband.h | 32 ++++++++++++++++++++++++++++
 2 files changed, 77 insertions(+)
 create mode 100644 firmware/common/bitband.c
 create mode 100644 firmware/common/bitband.h

diff --git a/firmware/common/bitband.c b/firmware/common/bitband.c
new file mode 100644
index 00000000..82ba5383
--- /dev/null
+++ b/firmware/common/bitband.c
@@ -0,0 +1,45 @@
+/*
+ * Copyright 2012 Jared Boone
+ *
+ * This file is part of HackRF.
+ *
+ * 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, or (at your option)
+ * 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; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "bitband.h"
+
+volatile uint_fast8_t* peripheral_bitband_address(volatile void* const address, const uint_fast8_t bit_number) {
+    const uint32_t bit_band_base = 0x42000000;
+    const uint32_t byte_offset = (uint32_t)address - 0x40000000;
+    const uint32_t bit_word_offset = (byte_offset * 32) + (bit_number * 4);
+    const uint32_t bit_word_address = bit_band_base + bit_word_offset;
+    return (volatile uint_fast8_t*)bit_word_address;
+}
+
+void peripheral_bitband_set(volatile void* const peripheral_address, const uint_fast8_t bit_number) {
+    volatile uint_fast8_t* const bitband_address = peripheral_bitband_address(peripheral_address, bit_number);
+    *bitband_address = 1;
+}
+
+void peripheral_bitband_clear(volatile void* const peripheral_address, const uint_fast8_t bit_number) {
+    volatile uint_fast8_t* const bitband_address = peripheral_bitband_address(peripheral_address, bit_number);
+    *bitband_address = 0;
+}
+
+uint_fast8_t peripheral_bitband_get(volatile void* const peripheral_address, const uint_fast8_t bit_number) {
+    volatile uint_fast8_t* const bitband_address = peripheral_bitband_address(peripheral_address, bit_number);
+    return *bitband_address;
+}
diff --git a/firmware/common/bitband.h b/firmware/common/bitband.h
new file mode 100644
index 00000000..20407b5d
--- /dev/null
+++ b/firmware/common/bitband.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2012 Jared Boone
+ *
+ * This file is part of HackRF.
+ *
+ * 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, or (at your option)
+ * 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; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __BITBAND_H__
+#define __BITBAND_H__
+
+#include <stdint.h>
+
+volatile uint_fast8_t* peripheral_bitband_address(volatile void* const address, const uint_fast8_t bit_number);
+void peripheral_bitband_set(volatile void* const peripheral_address, const uint_fast8_t bit_number);
+void peripheral_bitband_clear(volatile void* const peripheral_address, const uint_fast8_t bit_number);
+uint_fast8_t peripheral_bitband_get(volatile void* const peripheral_address, const uint_fast8_t bit_number);
+
+#endif//__BITBAND_H__