fdt: Add tests for fdtdec

The fdtdec_find_aliases_for_id() function is complicated enough that
it really should have some tests. This does not necessarily need to be
committed to U-Boot, but it might be useful.

(note there are a few minor inconsistencies with this patch which will be
cleaned up when the USB series is applied)

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>

lib/Makefile

@@ -40,6 +40,7 @@ COBJS-y += crc32.o
 COBJS-y += display_options.o
 COBJS-y += errno.o
 COBJS-$(CONFIG_OF_CONTROL) += fdtdec.o
+COBJS-$(CONFIG_TEST_FDTDEC) += fdtdec_test.o
 COBJS-$(CONFIG_GZIP) += gunzip.o
 COBJS-y += hashtable.o
 COBJS-$(CONFIG_LMB) += lmb.o

lib/fdtdec_test.c

@@ -0,0 +1,226 @@
+/*
+ * Some very basic tests for fdtdec, accessed through test_fdtdec command.
+ * They are easiest to use with sandbox.
+ *
+ * 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
+ */
+
+#include <common.h>
+#include <fdtdec.h>
+#include <libfdt.h>
+#include <malloc.h>
+#include <os.h>
+
+/* The size of our test fdt blob */
+#define FDT_SIZE	(16 * 1024)
+
+/**
+ * Check if an operation failed, and if so, print an error
+ *
+ * @param oper_name	Name of operation
+ * @param err		Error code to check
+ *
+ * @return 0 if ok, -1 if there was an error
+ */
+static int fdt_checkerr(const char *oper_name, int err)
+{
+	if (err) {
+		printf("%s: %s: %s\n", __func__, oper_name, fdt_strerror(err));
+		return -1;
+	}
+
+	return 0;
+}
+
+/**
+ * Check the result of an operation and if incorrect, print an error
+ *
+ * @param oper_name	Name of operation
+ * @param expected	Expected value
+ * @param value		Actual value
+ *
+ * @return 0 if ok, -1 if there was an error
+ */
+static int checkval(const char *oper_name, int expected, int value)
+{
+	if (expected != value) {
+		printf("%s: %s: expected %d, but returned %d\n", __func__,
+		       oper_name, expected, value);
+		return -1;
+	}
+
+	return 0;
+}
+
+#define CHECK(op)	if (fdt_checkerr(#op, op)) return -1
+#define CHECKVAL(op, expected)	\
+	if (checkval(#op, expected, op)) \
+		return -1
+#define CHECKOK(op)	CHECKVAL(op, 0)
+
+/* maximum number of nodes / aliases to generate */
+#define MAX_NODES	20
+
+/*
+ * Make a test fdt
+ *
+ * @param fdt		Device tree pointer
+ * @param size		Size of device tree blob
+ * @param aliases	Specifies alias assignments. Format is a list of items
+ *			separated by space. Items are #a where
+ *				# is the alias number
+ *				a is the node to point to
+ * @param nodes		Specifies nodes to generate (a=0, b=1), upper case
+ *			means to create a disabled node
+ */
+static int make_fdt(void *fdt, int size, const char *aliases,
+		    const char *nodes)
+{
+	char name[20], value[20];
+	const char *s;
+	int fd;
+
+	CHECK(fdt_create(fdt, size));
+	CHECK(fdt_finish_reservemap(fdt));
+	CHECK(fdt_begin_node(fdt, ""));
+
+	CHECK(fdt_begin_node(fdt, "aliases"));
+	for (s = aliases; *s;) {
+		sprintf(name, "i2c%c", *s);
+		sprintf(value, "/i2c%d@0", s[1] - 'a');
+		CHECK(fdt_property_string(fdt, name, value));
+		s += 2 + (s[2] != '\0');
+	}
+	CHECK(fdt_end_node(fdt));
+
+	for (s = nodes; *s; s++) {
+		sprintf(value, "i2c%d@0", (*s & 0xdf) - 'A');
+		CHECK(fdt_begin_node(fdt, value));
+		CHECK(fdt_property_string(fdt, "compatible",
+			fdtdec_get_compatible(COMPAT_UNKNOWN)));
+		if (*s <= 'Z')
+			CHECK(fdt_property_string(fdt, "status", "disabled"));
+		CHECK(fdt_end_node(fdt));
+	}
+
+	CHECK(fdt_end_node(fdt));
+	CHECK(fdt_finish(fdt));
+	CHECK(fdt_pack(fdt));
+#if defined(DEBUG) && defined(CONFIG_SANDBOX)
+	fd = os_open("/tmp/fdtdec-text.dtb", OS_O_CREAT | OS_O_WRONLY);
+	if (fd == -1) {
+		printf("Could not open .dtb file to write\n");
+		return -1;
+	}
+	os_write(fd, fdt, size);
+	os_close(fd);
+#endif
+	return 0;
+}
+
+static int run_test(const char *aliases, const char *nodes, const char *expect)
+{
+	int list[MAX_NODES];
+	const char *s;
+	void *blob;
+	int i;
+
+	blob = malloc(FDT_SIZE);
+	if (!blob) {
+		printf("%s: out of memory\n", __func__);
+		return 1;
+	}
+
+	printf("aliases=%s, nodes=%s, expect=%s: ", aliases, nodes, expect);
+	CHECKVAL(make_fdt(blob, FDT_SIZE, aliases, nodes), 0);
+	CHECKVAL(fdtdec_find_aliases_for_id(blob, "i2c",
+			COMPAT_UNKNOWN,
+			list, ARRAY_SIZE(list)), strlen(expect));
+
+	/* Check we got the right ones */
+	for (i = 0, s = expect; *s; s++, i++) {
+		int want = *s;
+		const char *name;
+		int got = ' ';
+
+		name = list[i] ? fdt_get_name(blob, list[i], NULL) : NULL;
+		if (name)
+			got = name[3] + 'a' - '0';
+
+		if (got != want) {
+			printf("Position %d: Expected '%c', got '%c' ('%s')\n",
+			       i, want, got, name);
+			return 1;
+		}
+	}
+
+	printf("pass\n");
+	return 0;
+}
+
+static int do_test_fdtdec(cmd_tbl_t *cmdtp, int flag, int argc,
+			  char * const argv[])
+{
+	/* basic tests */
+	CHECKOK(run_test("", "", ""));
+	CHECKOK(run_test("1e 3d", "", ""));
+
+	/*
+	 * 'a' represents 0, 'b' represents 1, etc.
+	 * The first character is the alias number, the second is the node
+	 * number. So the params mean:
+	 * 0a 1b	: point alias 0 to node 0 (a), alias 1 to node 1(b)
+	 * ab		: to create nodes 0 and 1 (a and b)
+	 * ab		: we expect the function to return two nodes, in
+	 *		  the order 0, 1
+	 */
+	CHECKOK(run_test("0a 1b", "ab", "ab"));
+
+	CHECKOK(run_test("0a 1c", "ab", "ab"));
+	CHECKOK(run_test("1c", "ab", "ab"));
+	CHECKOK(run_test("1b", "ab", "ab"));
+	CHECKOK(run_test("0b", "ab", "ba"));
+	CHECKOK(run_test("0b 2d", "dbc", "bcd"));
+	CHECKOK(run_test("0d 3a 1c 2b", "dbac", "dcba"));
+
+	/* things with holes */
+	CHECKOK(run_test("1b 3d", "dbc", "cb d"));
+	CHECKOK(run_test("1e 3d", "dbc", "bc d"));
+
+	/* no aliases */
+	CHECKOK(run_test("", "dbac", "dbac"));
+
+	/* disabled nodes */
+	CHECKOK(run_test("0d 3a 1c 2b", "dBac", "dc a"));
+	CHECKOK(run_test("0b 2d", "DBc", "c"));
+	CHECKOK(run_test("0b 4d 2c", "DBc", "  c"));
+
+	/* conflicting aliases - first one gets it */
+	CHECKOK(run_test("2a 1a 0a", "a", "  a"));
+	CHECKOK(run_test("0a 1a 2a", "a", "a"));
+
+	printf("Test passed\n");
+	return 0;
+}
+
+U_BOOT_CMD(
+	test_fdtdec, 3, 1, do_test_fdtdec,
+	"test_fdtdec",
+	"Run tests for fdtdec library");