mtd: parsers: Move OF parser

This moves the OF/device tree partition parser down into the
parser subdirectory. No functional change.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Richard Weinberger <richard@nod.at>

3 files changed, 247 insertions, 0 deletions

diff --git a/drivers/mtd/parsers/Kconfig b/drivers/mtd/parsers/Kconfig
index e356b4311d4d..2001d96cb82a 100644
--- a/drivers/mtd/parsers/Kconfig
+++ b/drivers/mtd/parsers/Kconfig
@@ -20,6 +20,16 @@ config MTD_BCM63XX_PARTS
 	  This provides partition parsing for BCM63xx devices with CFE
 	  bootloaders.
 
+config MTD_OF_PARTS
+	tristate "OpenFirmware (device tree) partitioning parser"
+	default y
+	depends on OF
+	help
+	  This provides a open firmware device tree partition parser
+	  which derives the partition map from the children of the
+	  flash memory node, as described in
+	  Documentation/devicetree/bindings/mtd/partition.txt.
+
 config MTD_PARSER_IMAGETAG
 	tristate "Parser for BCM963XX Image Tag format partitions"
 	depends on BCM63XX || BMIPS_GENERIC || COMPILE_TEST
diff --git a/drivers/mtd/parsers/Makefile b/drivers/mtd/parsers/Makefile
index 582def540880..69b2c5289f96 100644
--- a/drivers/mtd/parsers/Makefile
+++ b/drivers/mtd/parsers/Makefile
@@ -2,6 +2,7 @@
 obj-$(CONFIG_MTD_AR7_PARTS)		+= ar7part.o
 obj-$(CONFIG_MTD_BCM47XX_PARTS)		+= bcm47xxpart.o
 obj-$(CONFIG_MTD_BCM63XX_PARTS)		+= bcm63xxpart.o
+obj-$(CONFIG_MTD_OF_PARTS)		+= ofpart.o
 obj-$(CONFIG_MTD_PARSER_IMAGETAG)	+= parser_imagetag.o
 obj-$(CONFIG_MTD_AFS_PARTS)		+= afs.o
 obj-$(CONFIG_MTD_PARSER_TRX)		+= parser_trx.o
diff --git a/drivers/mtd/parsers/ofpart.c b/drivers/mtd/parsers/ofpart.c
new file mode 100644
index 000000000000..3caeabf27987
--- /dev/null
+++ b/drivers/mtd/parsers/ofpart.c
@@ -0,0 +1,236 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Flash partitions described by the OF (or flattened) device tree
+ *
+ * Copyright © 2006 MontaVista Software Inc.
+ * Author: Vitaly Wool <vwool@ru.mvista.com>
+ *
+ * Revised to handle newer style flash binding by:
+ *   Copyright © 2007 David Gibson, IBM Corporation.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/mtd/mtd.h>
+#include <linux/slab.h>
+#include <linux/mtd/partitions.h>
+
+static bool node_has_compatible(struct device_node *pp)
+{
+	return of_get_property(pp, "compatible", NULL);
+}
+
+static int parse_fixed_partitions(struct mtd_info *master,
+				  const struct mtd_partition **pparts,
+				  struct mtd_part_parser_data *data)
+{
+	struct mtd_partition *parts;
+	struct device_node *mtd_node;
+	struct device_node *ofpart_node;
+	const char *partname;
+	struct device_node *pp;
+	int nr_parts, i, ret = 0;
+	bool dedicated = true;
+
+
+	/* Pull of_node from the master device node */
+	mtd_node = mtd_get_of_node(master);
+	if (!mtd_node)
+		return 0;
+
+	ofpart_node = of_get_child_by_name(mtd_node, "partitions");
+	if (!ofpart_node) {
+		/*
+		 * We might get here even when ofpart isn't used at all (e.g.,
+		 * when using another parser), so don't be louder than
+		 * KERN_DEBUG
+		 */
+		pr_debug("%s: 'partitions' subnode not found on %pOF. Trying to parse direct subnodes as partitions.\n",
+			 master->name, mtd_node);
+		ofpart_node = mtd_node;
+		dedicated = false;
+	} else if (!of_device_is_compatible(ofpart_node, "fixed-partitions")) {
+		/* The 'partitions' subnode might be used by another parser */
+		return 0;
+	}
+
+	/* First count the subnodes */
+	nr_parts = 0;
+	for_each_child_of_node(ofpart_node,  pp) {
+		if (!dedicated && node_has_compatible(pp))
+			continue;
+
+		nr_parts++;
+	}
+
+	if (nr_parts == 0)
+		return 0;
+
+	parts = kcalloc(nr_parts, sizeof(*parts), GFP_KERNEL);
+	if (!parts)
+		return -ENOMEM;
+
+	i = 0;
+	for_each_child_of_node(ofpart_node,  pp) {
+		const __be32 *reg;
+		int len;
+		int a_cells, s_cells;
+
+		if (!dedicated && node_has_compatible(pp))
+			continue;
+
+		reg = of_get_property(pp, "reg", &len);
+		if (!reg) {
+			if (dedicated) {
+				pr_debug("%s: ofpart partition %pOF (%pOF) missing reg property.\n",
+					 master->name, pp,
+					 mtd_node);
+				goto ofpart_fail;
+			} else {
+				nr_parts--;
+				continue;
+			}
+		}
+
+		a_cells = of_n_addr_cells(pp);
+		s_cells = of_n_size_cells(pp);
+		if (len / 4 != a_cells + s_cells) {
+			pr_debug("%s: ofpart partition %pOF (%pOF) error parsing reg property.\n",
+				 master->name, pp,
+				 mtd_node);
+			goto ofpart_fail;
+		}
+
+		parts[i].offset = of_read_number(reg, a_cells);
+		parts[i].size = of_read_number(reg + a_cells, s_cells);
+		parts[i].of_node = pp;
+
+		partname = of_get_property(pp, "label", &len);
+		if (!partname)
+			partname = of_get_property(pp, "name", &len);
+		parts[i].name = partname;
+
+		if (of_get_property(pp, "read-only", &len))
+			parts[i].mask_flags |= MTD_WRITEABLE;
+
+		if (of_get_property(pp, "lock", &len))
+			parts[i].mask_flags |= MTD_POWERUP_LOCK;
+
+		i++;
+	}
+
+	if (!nr_parts)
+		goto ofpart_none;
+
+	*pparts = parts;
+	return nr_parts;
+
+ofpart_fail:
+	pr_err("%s: error parsing ofpart partition %pOF (%pOF)\n",
+	       master->name, pp, mtd_node);
+	ret = -EINVAL;
+ofpart_none:
+	of_node_put(pp);
+	kfree(parts);
+	return ret;
+}
+
+static const struct of_device_id parse_ofpart_match_table[] = {
+	{ .compatible = "fixed-partitions" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, parse_ofpart_match_table);
+
+static struct mtd_part_parser ofpart_parser = {
+	.parse_fn = parse_fixed_partitions,
+	.name = "fixed-partitions",
+	.of_match_table = parse_ofpart_match_table,
+};
+
+static int parse_ofoldpart_partitions(struct mtd_info *master,
+				      const struct mtd_partition **pparts,
+				      struct mtd_part_parser_data *data)
+{
+	struct mtd_partition *parts;
+	struct device_node *dp;
+	int i, plen, nr_parts;
+	const struct {
+		__be32 offset, len;
+	} *part;
+	const char *names;
+
+	/* Pull of_node from the master device node */
+	dp = mtd_get_of_node(master);
+	if (!dp)
+		return 0;
+
+	part = of_get_property(dp, "partitions", &plen);
+	if (!part)
+		return 0; /* No partitions found */
+
+	pr_warn("Device tree uses obsolete partition map binding: %pOF\n", dp);
+
+	nr_parts = plen / sizeof(part[0]);
+
+	parts = kcalloc(nr_parts, sizeof(*parts), GFP_KERNEL);
+	if (!parts)
+		return -ENOMEM;
+
+	names = of_get_property(dp, "partition-names", &plen);
+
+	for (i = 0; i < nr_parts; i++) {
+		parts[i].offset = be32_to_cpu(part->offset);
+		parts[i].size   = be32_to_cpu(part->len) & ~1;
+		/* bit 0 set signifies read only partition */
+		if (be32_to_cpu(part->len) & 1)
+			parts[i].mask_flags = MTD_WRITEABLE;
+
+		if (names && (plen > 0)) {
+			int len = strlen(names) + 1;
+
+			parts[i].name = names;
+			plen -= len;
+			names += len;
+		} else {
+			parts[i].name = "unnamed";
+		}
+
+		part++;
+	}
+
+	*pparts = parts;
+	return nr_parts;
+}
+
+static struct mtd_part_parser ofoldpart_parser = {
+	.parse_fn = parse_ofoldpart_partitions,
+	.name = "ofoldpart",
+};
+
+static int __init ofpart_parser_init(void)
+{
+	register_mtd_parser(&ofpart_parser);
+	register_mtd_parser(&ofoldpart_parser);
+	return 0;
+}
+
+static void __exit ofpart_parser_exit(void)
+{
+	deregister_mtd_parser(&ofpart_parser);
+	deregister_mtd_parser(&ofoldpart_parser);
+}
+
+module_init(ofpart_parser_init);
+module_exit(ofpart_parser_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
+MODULE_AUTHOR("Vitaly Wool, David Gibson");
+/*
+ * When MTD core cannot find the requested parser, it tries to load the module
+ * with the same name. Since we provide the ofoldpart parser, we should have
+ * the corresponding alias.
+ */
+MODULE_ALIAS("fixed-partitions");
+MODULE_ALIAS("ofoldpart");