kernel-ark/drivers/mtd/ofpart.c
Brian Norris b9adf469f8 mtd: partitions: make parsers return 'const' partition arrays
We only want to modify these arrays inside the parser "drivers", so the
drivers should construct them however they like, then return them as
immutable arrays.

This will make other refactorings easier.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
2015-12-09 10:21:57 -08:00

233 lines
5.6 KiB
C

/*
* 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.
*
* 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.
*/
#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_ofpart_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 %s. Trying to parse direct subnodes as partitions.\n",
master->name, mtd_node->full_name);
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 = kzalloc(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 %s (%s) missing reg property.\n",
master->name, pp->full_name,
mtd_node->full_name);
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 %s (%s) error parsing reg property.\n",
master->name, pp->full_name,
mtd_node->full_name);
goto ofpart_fail;
}
parts[i].offset = of_read_number(reg, a_cells);
parts[i].size = of_read_number(reg + a_cells, s_cells);
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 %s (%s)\n",
master->name, pp->full_name, mtd_node->full_name);
ret = -EINVAL;
ofpart_none:
of_node_put(pp);
kfree(parts);
return ret;
}
static struct mtd_part_parser ofpart_parser = {
.parse_fn = parse_ofpart_partitions,
.name = "ofpart",
};
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_warning("Device tree uses obsolete partition map binding: %s\n",
dp->full_name);
nr_parts = plen / sizeof(part[0]);
parts = kzalloc(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("ofoldpart");