mtd: parsers: ofpart: support BCM4908 fixed partitions

Some devices use fixed partitioning with some partitions requiring some
extra logic. E.g. BCM4908 may have multiple firmware partitions but
detecting currently used one requires checking bootloader parameters.

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 support in ofpart can be enabled using config option and results
in compiling & executing a specific callback. It 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>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210301105823.31032-1-zajec5@gmail.com
This commit is contained in:
Rafał Miłecki 2021-03-01 11:58:23 +01:00 committed by Miquel Raynal
parent 462d69a2dc
commit bb17230c61
5 changed files with 116 additions and 2 deletions

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@ -67,6 +67,15 @@ config MTD_OF_PARTS
flash memory node, as described in
Documentation/devicetree/bindings/mtd/partition.txt.
config MTD_OF_PARTS_BCM4908
bool "BCM4908 partitioning support"
depends on MTD_OF_PARTS && (ARCH_BCM4908 || COMPILE_TEST)
default ARCH_BCM4908
help
This provides partitions parser for BCM4908 family devices
that can have multiple "firmware" partitions. It takes care of
finding currently used one and backup ones.
config MTD_PARSER_IMAGETAG
tristate "Parser for BCM963XX Image Tag format partitions"
depends on BCM63XX || BMIPS_GENERIC || COMPILE_TEST

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@ -4,6 +4,8 @@ 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
ofpart-y += ofpart_core.o
ofpart-$(CONFIG_MTD_OF_PARTS_BCM4908) += ofpart_bcm4908.o
obj-$(CONFIG_MTD_PARSER_IMAGETAG) += parser_imagetag.o
obj-$(CONFIG_MTD_AFS_PARTS) += afs.o
obj-$(CONFIG_MTD_PARSER_TRX) += parser_trx.o

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@ -0,0 +1,64 @@
// 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>
#include "ofpart_bcm4908.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;
}

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@ -0,0 +1,15 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __BCM4908_PARTITIONS_H
#define __BCM4908_PARTITIONS_H
#ifdef CONFIG_MTD_OF_PARTS_BCM4908
int bcm4908_partitions_post_parse(struct mtd_info *mtd, struct mtd_partition *parts, int nr_parts);
#else
static inline int bcm4908_partitions_post_parse(struct mtd_info *mtd, struct mtd_partition *parts,
int nr_parts)
{
return -EOPNOTSUPP;
}
#endif
#endif

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@ -16,6 +16,18 @@
#include <linux/slab.h>
#include <linux/mtd/partitions.h>
#include "ofpart_bcm4908.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 @@ ofpart_none:
}
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);