Add bitfield access macros

To use these, set things up like this:

#define UART_PA_START 0x67000000        Physical address of UART
struct uart_ctlr *uart = (struct uart_ctlr *)UART_PA_START;

#define UART_FBCON_RANGE  5:3           Bit range for the FBCON field
enum {                                  An enum with allowed values
        UART_FBCON_OFF,
        UART_FBCON_ON,
        UART_FBCON_MULTI,
        UART_FBCON_SLAVE,
};

This defines a bit field of 3 bits starting at bit 5 and extending down
to bit 3, i.e. 5:3

Then:
   bitfield_unpack(UART_FBCON)
        - return the value of bits 5:3 (shifted down to bits 2:0)

   bitfield_pack(UART_FBCON, 4)
        - return a word with that field set to 4 (so in this case (4 << 3))

   bitfield_set(UART_FBCON, word, val
        - update a field within word so that its value is val.

   bitfield_enum_writel(UART_FBCON, MULTI, &uart->fbcon)
        - set the UART's FBCON field to MULTI

Change-Id: Id90aa0538093d67c917df2d744c0ebff1fe03b6f

BUG=chromium-os:13875
TEST=cd test; make

Review URL: http://codereview.chromium.org/6883058

2 files changed, 264 insertions, 0 deletions

diff --git a/test/Makefile b/test/Makefile
new file mode 100644
index 0000000000..6d8c6a77c8
--- /dev/null
+++ b/test/Makefile
@@ -0,0 +1,36 @@
+# Copyright (c) 2011 The Chromium OS Authors.
+# See file CREDITS for list of people who contributed to this
+# project.
+#
+# 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 (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; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+
+TESTS=bitfield
+
+INC=../arch/arm/include/asm/arch-tegra2
+CFLAGS=-DDEBUG -I$(INC)
+
+all: tests run
+
+tests: $(TESTS)
+
+bitfield: bitfield.o
+
+bitfield.o: $(INC)/bitfield.h
+
+run:
+	@echo "Running tests $(TESTS)"
+	@./bitfield
+	@echo "Tests completed."
diff --git a/test/bitfield.c b/test/bitfield.c
new file mode 100644
index 0000000000..3f4c4b45ea
--- /dev/null
+++ b/test/bitfield.c
@@ -0,0 +1,228 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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 (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; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/*
+ * Bitfield test routines
+ *
+ */
+
+#include <stdio.h>
+
+#include "bitfield.h"
+
+
+#define FULL_RANGE		31:0
+#define HIGH_RANGE		31:30
+#define MID_RANGE		23:16
+#define LOW_RANGE		2:0
+#define HIGH_SINGLE_RANGE	31:31
+#define MID_SINGLE_RANGE	16:16
+#define LOW_SINGLE_RANGE	0:0
+
+static int test_count = 0;
+
+#ifdef DEBUG
+#define assert(x) 	\
+	({ test_count++; if (!(x)) printf("Assertion failure '%s' %s line %d\n", \
+		#x, __FILE__, __LINE__) })
+#define asserteq(x, y) 	\
+	({ int _x = x; int _y = y; test_count++; \
+		if (_x != _y) \
+		printf("Assertion failure at %s:%d: '%s' %#x != '%s' %#x\n", \
+			__FILE__, __LINE__, #x, _x, #y, _y); })
+#else
+#define assert(x) test_count++
+#define asserteq(x,y) test_count++
+#endif
+
+
+static void test_low_high(void)
+{
+	asserteq(BITFIELD_HIGHBIT(FULL_RANGE), 31);
+	asserteq(BITFIELD_LOWBIT(FULL_RANGE), 0);
+	asserteq(BITFIELD_HIGHBIT(HIGH_RANGE), 31);
+	asserteq(BITFIELD_LOWBIT(HIGH_RANGE), 30);
+	asserteq(BITFIELD_HIGHBIT(MID_RANGE), 23);
+	asserteq(BITFIELD_LOWBIT(MID_RANGE), 16);
+	asserteq(BITFIELD_HIGHBIT(LOW_RANGE), 2);
+	asserteq(BITFIELD_LOWBIT(LOW_RANGE), 0);
+	asserteq(BITFIELD_HIGHBIT(HIGH_SINGLE_RANGE), 31);
+	asserteq(BITFIELD_LOWBIT(HIGH_SINGLE_RANGE), 31);
+	asserteq(BITFIELD_HIGHBIT(MID_SINGLE_RANGE), 16);
+	asserteq(BITFIELD_LOWBIT(MID_SINGLE_RANGE), 16);
+	asserteq(BITFIELD_HIGHBIT(LOW_SINGLE_RANGE), 0);
+	asserteq(BITFIELD_LOWBIT(LOW_SINGLE_RANGE), 0);
+}
+
+static void test_width(void)
+{
+	asserteq(BITFIELD_WIDTH(FULL_RANGE), 32);
+	asserteq(BITFIELD_WIDTH(HIGH_RANGE), 2);
+	asserteq(BITFIELD_WIDTH(MID_RANGE), 8);
+	asserteq(BITFIELD_WIDTH(LOW_RANGE), 3);
+	asserteq(BITFIELD_WIDTH(HIGH_SINGLE_RANGE), 1);
+	asserteq(BITFIELD_WIDTH(MID_SINGLE_RANGE), 1);
+	asserteq(BITFIELD_WIDTH(LOW_SINGLE_RANGE), 1);
+}
+
+static void test_shift(void)
+{
+	asserteq(bf_shift(FULL), 0);
+	asserteq(bf_shift(HIGH), 30);
+	asserteq(bf_shift(MID), 16);
+	asserteq(bf_shift(LOW), 0);
+	asserteq(bf_shift(HIGH_SINGLE), 31);
+	asserteq(bf_shift(MID_SINGLE), 16);
+	asserteq(bf_shift(LOW_SINGLE), 0);
+}
+
+static void test_rawmask(void)
+{
+	asserteq(bf_rawmask(FULL), 0xffffffffU);
+	asserteq(bf_rawmask(HIGH), 0x3);
+	asserteq(bf_rawmask(MID), 0xff);
+	asserteq(bf_rawmask(LOW), 0x7);
+	asserteq(bf_rawmask(HIGH_SINGLE), 0x1);
+	asserteq(bf_rawmask(MID_SINGLE), 0x1);
+	asserteq(bf_rawmask(LOW_SINGLE), 0x1);
+}
+
+static void test_mask(void)
+{
+	asserteq(bf_mask(FULL), 0xffffffffU);
+	asserteq(bf_mask(HIGH), 0xc0000000);
+	asserteq(bf_mask(MID), 0x00ff0000);
+	asserteq(bf_mask(LOW), 0x7);
+	asserteq(bf_mask(HIGH_SINGLE), 0x80000000U);
+	asserteq(bf_mask(MID_SINGLE), 0x00010000);
+	asserteq(bf_mask(LOW_SINGLE), 0x1);
+}
+
+static void test_unpack(void)
+{
+	asserteq(bf_unpack(FULL, 0), 0);
+	asserteq(bf_unpack(FULL, -1U), -1U);
+	asserteq(bf_unpack(FULL, 0x12345678), 0x12345678);
+	asserteq(bf_unpack(FULL, 0x87654321), 0x87654321);
+	asserteq(bf_unpack(FULL, 0xa5a5a5a6), 0xa5a5a5a6);
+
+	asserteq(bf_unpack(HIGH, 0), 0);
+	asserteq(bf_unpack(HIGH, -1U), 3);
+	asserteq(bf_unpack(HIGH, 0x12345678), 0);
+	asserteq(bf_unpack(HIGH, 0x87654321), 2);
+	asserteq(bf_unpack(HIGH, 0xa5a5a5a6), 2);
+
+	asserteq(bf_unpack(MID, 0), 0);
+	asserteq(bf_unpack(MID, -1U), 0xff);
+	asserteq(bf_unpack(MID, 0x12345678), 0x34);
+	asserteq(bf_unpack(MID, 0x87654321), 0x65);
+	asserteq(bf_unpack(MID, 0xa5a5a5a6), 0xa5);
+
+	asserteq(bf_unpack(LOW, 0), 0);
+	asserteq(bf_unpack(LOW, -1U), 7);
+	asserteq(bf_unpack(LOW, 0x12345678), 0);
+	asserteq(bf_unpack(LOW, 0x87654321), 1);
+	asserteq(bf_unpack(LOW, 0xa5a5a5a6), 6);
+
+	asserteq(bf_unpack(HIGH_SINGLE, 0), 0);
+	asserteq(bf_unpack(HIGH_SINGLE, -1U), 1);
+	asserteq(bf_unpack(HIGH_SINGLE, 0x12345678), 0);
+	asserteq(bf_unpack(HIGH_SINGLE, 0x87654321), 1);
+	asserteq(bf_unpack(HIGH_SINGLE, 0xa5a5a5a6), 1);
+
+	asserteq(bf_unpack(MID_SINGLE, 0), 0);
+	asserteq(bf_unpack(MID_SINGLE, -1U), 1);
+	asserteq(bf_unpack(MID_SINGLE, 0x12345678), 0);
+	asserteq(bf_unpack(MID_SINGLE, 0x87654321), 1);
+	asserteq(bf_unpack(MID_SINGLE, 0xa5a5a5a6), 1);
+
+	asserteq(bf_unpack(LOW_SINGLE, 0), 0);
+	asserteq(bf_unpack(LOW_SINGLE, -1U), 1);
+	asserteq(bf_unpack(LOW_SINGLE, 0x12345678), 0);
+	asserteq(bf_unpack(LOW_SINGLE, 0x87654321), 1);
+	asserteq(bf_unpack(LOW_SINGLE, 0xa5a5a5a6), 0);
+}
+
+static void test_pack(void)
+{
+	asserteq(bf_pack(FULL, 0), 0);
+	asserteq(bf_pack(FULL, -1U), -1U);
+	asserteq(bf_pack(FULL, 0x12345678), 0x12345678);
+	asserteq(bf_pack(FULL, 0x87654321), 0x87654321);
+	asserteq(bf_pack(FULL, 0xa5a5a5a6), 0xa5a5a5a6);
+
+	asserteq(bf_pack(HIGH, 0), 0);
+	asserteq(bf_pack(HIGH, -1U), 0xc0000000);
+	asserteq(bf_pack(HIGH, 0x12345678), 0);
+	asserteq(bf_pack(HIGH, 0x87654321), 0x40000000);
+	asserteq(bf_pack(HIGH, 0xa5a5a5a6), 0x80000000);
+
+	asserteq(bf_pack(MID, 0), 0);
+	asserteq(bf_pack(MID, -1U), 0x00ff0000);
+	asserteq(bf_pack(MID, 0x12345678), 0x00780000);
+	asserteq(bf_pack(MID, 0x87654321), 0x00210000);
+	asserteq(bf_pack(MID, 0xa5a5a5a6), 0x00a60000);
+
+	asserteq(bf_pack(LOW, 0), 0);
+	asserteq(bf_pack(LOW, -1U), 7);
+	asserteq(bf_pack(LOW, 0x12345678), 0);
+	asserteq(bf_pack(LOW, 0x87654321), 1);
+	asserteq(bf_pack(LOW, 0xa5a5a5a6), 6);
+
+	asserteq(bf_pack(HIGH_SINGLE, 0), 0);
+	asserteq(bf_pack(HIGH_SINGLE, -1U), 0x80000000u);
+	asserteq(bf_pack(HIGH_SINGLE, 0x12345678), 0);
+	asserteq(bf_pack(HIGH_SINGLE, 0x87654321), 0x80000000u);
+	asserteq(bf_pack(HIGH_SINGLE, 0xa5a5a5a6), 0x00000000u);
+
+	asserteq(bf_pack(MID_SINGLE, 0), 0);
+	asserteq(bf_pack(MID_SINGLE, -1U), 0x00010000);
+	asserteq(bf_pack(MID_SINGLE, 0x12345678), 0);
+	asserteq(bf_pack(MID_SINGLE, 0x87654321), 0x00010000);
+	asserteq(bf_pack(MID_SINGLE, 0xa5a5a5a6), 0x00000000);
+
+	asserteq(bf_pack(LOW_SINGLE, 0), 0);
+	asserteq(bf_pack(LOW_SINGLE, -1U), 1);
+	asserteq(bf_pack(LOW_SINGLE, 0x12345678), 0);
+	asserteq(bf_pack(LOW_SINGLE, 0x87654321), 1);
+	asserteq(bf_pack(LOW_SINGLE, 0xa5a5a5a6), 0);
+}
+
+static void test_set(void)
+{
+}
+
+void bf_test(void)
+{
+	test_low_high();
+	test_width();
+	test_shift();
+	test_rawmask();
+	test_unpack();
+	test_pack();
+}
+
+int main(int argc, char *argv[])
+{
+	bf_test();
+	printf("%d tests run\n", test_count);
+	return 0;
+}