diff mbox series

[3/3] mtd: parsers: ofpart: support BCM4908 fixed partitions

Message ID 20210115153901.31052-3-zajec5@gmail.com
State Changes Requested
Headers show
Series [1/3] dt-bindings: mtd: move partition binding to its own file | expand

Commit Message

Rafał Miłecki Jan. 15, 2021, 3:39 p.m. UTC
From: Rafał Miłecki <rafal@milecki.pl>

BCM4908 partitioning is based on fixed layout but allows specifying
multiple firmware partitions. It requires detecting which firmware
partition was used for booting current kernel.

To support such cases without duplicating a lot of code (without copying
most of the ofpart.c code) support for post-parsing callback was added.

BCM4908 callback simply reads offset of currently used firmware
partition from the DT. Bootloader specifies it using the "brcm_blparms"
property.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
---
 drivers/mtd/parsers/Makefile             |  1 +
 drivers/mtd/parsers/bcm4908-partitions.c | 62 ++++++++++++++++++++++++
 drivers/mtd/parsers/bcm4908-partitions.h |  7 +++
 drivers/mtd/parsers/ofpart.c             | 28 ++++++++++-
 4 files changed, 96 insertions(+), 2 deletions(-)
 create mode 100644 drivers/mtd/parsers/bcm4908-partitions.c
 create mode 100644 drivers/mtd/parsers/bcm4908-partitions.h

Comments

Miquel Raynal Jan. 19, 2021, 3:51 p.m. UTC | #1
Hi Rafał,

Rafał Miłecki <zajec5@gmail.com> wrote on Fri, 15 Jan 2021 16:39:01
+0100:

> From: Rafał Miłecki <rafal@milecki.pl>
> 
> BCM4908 partitioning is based on fixed layout but allows specifying
> multiple firmware partitions. It requires detecting which firmware
> partition was used for booting current kernel.
> 
> To support such cases without duplicating a lot of code (without copying
> most of the ofpart.c code) support for post-parsing callback was added.
> 
> BCM4908 callback simply reads offset of currently used firmware
> partition from the DT. Bootloader specifies it using the "brcm_blparms"
> property.
> 
> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

The approach looks fine by me, let's see what other maintainers think.


Cheers,
Miquèl
Richard Weinberger Jan. 22, 2021, 9:37 p.m. UTC | #2
On Tue, Jan 19, 2021 at 5:01 PM Miquel Raynal <miquel.raynal@bootlin.com> wrote:
> > Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
>
> The approach looks fine by me, let's see what other maintainers think.

Same, looks good to me! :-)
diff mbox series

Patch

diff --git a/drivers/mtd/parsers/Makefile b/drivers/mtd/parsers/Makefile
index b0c5f62f9e85..3e26001f743c 100644
--- a/drivers/mtd/parsers/Makefile
+++ b/drivers/mtd/parsers/Makefile
@@ -4,6 +4,7 @@  obj-$(CONFIG_MTD_BCM47XX_PARTS)		+= bcm47xxpart.o
 obj-$(CONFIG_MTD_BCM63XX_PARTS)		+= bcm63xxpart.o
 obj-$(CONFIG_MTD_CMDLINE_PARTS)		+= cmdlinepart.o
 obj-$(CONFIG_MTD_OF_PARTS)		+= ofpart.o
+obj-$(CONFIG_MTD_OF_PARTS)		+= bcm4908-partitions.o
 obj-$(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/bcm4908-partitions.c b/drivers/mtd/parsers/bcm4908-partitions.c
new file mode 100644
index 000000000000..032a4b1b8a5f
--- /dev/null
+++ b/drivers/mtd/parsers/bcm4908-partitions.c
@@ -0,0 +1,62 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Rafał Miłecki <rafal@milecki.pl>
+ */
+
+#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>
+
+#define BLPARAMS_FW_OFFSET		"NAND_RFS_OFS"
+
+static long long bcm4908_partitions_fw_offset(void)
+{
+	struct device_node *root;
+	struct property *prop;
+	const char *s;
+
+	root = of_find_node_by_path("/");
+	if (!root)
+		return -ENOENT;
+
+	of_property_for_each_string(root, "brcm_blparms", prop, s) {
+		size_t len = strlen(BLPARAMS_FW_OFFSET);
+		unsigned long offset;
+		int err;
+
+		if (strncmp(s, BLPARAMS_FW_OFFSET, len) || s[len] != '=')
+			continue;
+
+		err = kstrtoul(s + len + 1, 0, &offset);
+		if (err) {
+			pr_err("failed to parse %s\n", s + len + 1);
+			return err;
+		}
+
+		return offset << 10;
+	}
+
+	return -ENOENT;
+}
+
+int bcm4908_partitions_post_parse(struct mtd_info *mtd, struct mtd_partition *parts, int nr_parts)
+{
+	long long fw_offset;
+	int i;
+
+	fw_offset = bcm4908_partitions_fw_offset();
+
+	for (i = 0; i < nr_parts; i++) {
+		if (of_device_is_compatible(parts[i].of_node, "brcm,bcm4908-firmware")) {
+			if (fw_offset < 0 || parts[i].offset == fw_offset)
+				parts[i].name = "firmware";
+			else
+				parts[i].name = "backup";
+		}
+	}
+
+	return 0;
+}
diff --git a/drivers/mtd/parsers/bcm4908-partitions.h b/drivers/mtd/parsers/bcm4908-partitions.h
new file mode 100644
index 000000000000..df25f0487d0a
--- /dev/null
+++ b/drivers/mtd/parsers/bcm4908-partitions.h
@@ -0,0 +1,7 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __BCM4908_PARTITIONS_H
+#define __BCM4908_PARTITIONS_H
+
+int bcm4908_partitions_post_parse(struct mtd_info *mtd, struct mtd_partition *parts, int nr_parts);
+
+#endif
diff --git a/drivers/mtd/parsers/ofpart.c b/drivers/mtd/parsers/ofpart.c
index daf507c123e6..6b221df8401c 100644
--- a/drivers/mtd/parsers/ofpart.c
+++ b/drivers/mtd/parsers/ofpart.c
@@ -16,6 +16,18 @@ 
 #include <linux/slab.h>
 #include <linux/mtd/partitions.h>
 
+#include "bcm4908-partitions.h"
+
+struct fixed_partitions_quirks {
+	int (*post_parse)(struct mtd_info *mtd, struct mtd_partition *parts, int nr_parts);
+};
+
+struct fixed_partitions_quirks bcm4908_partitions_quirks = {
+	.post_parse = bcm4908_partitions_post_parse,
+};
+
+static const struct of_device_id parse_ofpart_match_table[];
+
 static bool node_has_compatible(struct device_node *pp)
 {
 	return of_get_property(pp, "compatible", NULL);
@@ -25,6 +37,8 @@  static int parse_fixed_partitions(struct mtd_info *master,
 				  const struct mtd_partition **pparts,
 				  struct mtd_part_parser_data *data)
 {
+	const struct fixed_partitions_quirks *quirks;
+	const struct of_device_id *of_id;
 	struct mtd_partition *parts;
 	struct device_node *mtd_node;
 	struct device_node *ofpart_node;
@@ -33,7 +47,6 @@  static int parse_fixed_partitions(struct mtd_info *master,
 	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)
@@ -50,11 +63,16 @@  static int parse_fixed_partitions(struct mtd_info *master,
 			 master->name, mtd_node);
 		ofpart_node = mtd_node;
 		dedicated = false;
-	} else if (!of_device_is_compatible(ofpart_node, "fixed-partitions")) {
+	}
+
+	of_id = of_match_node(parse_ofpart_match_table, ofpart_node);
+	if (dedicated && !of_id) {
 		/* The 'partitions' subnode might be used by another parser */
 		return 0;
 	}
 
+	quirks = of_id ? of_id->data : NULL;
+
 	/* First count the subnodes */
 	nr_parts = 0;
 	for_each_child_of_node(ofpart_node,  pp) {
@@ -126,6 +144,9 @@  static int parse_fixed_partitions(struct mtd_info *master,
 	if (!nr_parts)
 		goto ofpart_none;
 
+	if (quirks && quirks->post_parse)
+		quirks->post_parse(master, parts, nr_parts);
+
 	*pparts = parts;
 	return nr_parts;
 
@@ -140,7 +161,10 @@  static int parse_fixed_partitions(struct mtd_info *master,
 }
 
 static const struct of_device_id parse_ofpart_match_table[] = {
+	/* Generic */
 	{ .compatible = "fixed-partitions" },
+	/* Customized */
+	{ .compatible = "brcm,bcm4908-partitions", .data = &bcm4908_partitions_quirks, },
 	{},
 };
 MODULE_DEVICE_TABLE(of, parse_ofpart_match_table);