1/*
2 * Flash partitions described by the OF (or flattened) device tree
3 *
4 * Copyright © 2006 MontaVista Software Inc.
5 * Author: Vitaly Wool <vwool@ru.mvista.com>
6 *
7 * Revised to handle newer style flash binding by:
8 *   Copyright © 2007 David Gibson, IBM Corporation.
9 *
10 * This program is free software; you can redistribute  it and/or modify it
11 * under  the terms of  the GNU General  Public License as published by the
12 * Free Software Foundation;  either version 2 of the  License, or (at your
13 * option) any later version.
14 */
15
16#include <linux/module.h>
17#include <linux/init.h>
18#include <linux/of.h>
19#include <linux/mtd/mtd.h>
20#include <linux/slab.h>
21#include <linux/mtd/partitions.h>
22
23static bool node_has_compatible(struct device_node *pp)
24{
25	return of_get_property(pp, "compatible", NULL);
26}
27
28static int parse_ofpart_partitions(struct mtd_info *master,
29				   struct mtd_partition **pparts,
30				   struct mtd_part_parser_data *data)
31{
32	struct device_node *node;
33	const char *partname;
34	struct device_node *pp;
35	int nr_parts, i;
36
37
38	if (!data)
39		return 0;
40
41	node = data->of_node;
42	if (!node)
43		return 0;
44
45	/* First count the subnodes */
46	nr_parts = 0;
47	for_each_child_of_node(node,  pp) {
48		if (node_has_compatible(pp))
49			continue;
50
51		nr_parts++;
52	}
53
54	if (nr_parts == 0)
55		return 0;
56
57	*pparts = kzalloc(nr_parts * sizeof(**pparts), GFP_KERNEL);
58	if (!*pparts)
59		return -ENOMEM;
60
61	i = 0;
62	for_each_child_of_node(node,  pp) {
63		const __be32 *reg;
64		int len;
65		int a_cells, s_cells;
66
67		if (node_has_compatible(pp))
68			continue;
69
70		reg = of_get_property(pp, "reg", &len);
71		if (!reg) {
72			nr_parts--;
73			continue;
74		}
75
76		a_cells = of_n_addr_cells(pp);
77		s_cells = of_n_size_cells(pp);
78		(*pparts)[i].offset = of_read_number(reg, a_cells);
79		(*pparts)[i].size = of_read_number(reg + a_cells, s_cells);
80
81		partname = of_get_property(pp, "label", &len);
82		if (!partname)
83			partname = of_get_property(pp, "name", &len);
84		(*pparts)[i].name = partname;
85
86		if (of_get_property(pp, "read-only", &len))
87			(*pparts)[i].mask_flags |= MTD_WRITEABLE;
88
89		if (of_get_property(pp, "lock", &len))
90			(*pparts)[i].mask_flags |= MTD_POWERUP_LOCK;
91
92		i++;
93	}
94
95	if (!i) {
96		of_node_put(pp);
97		pr_err("No valid partition found on %s\n", node->full_name);
98		kfree(*pparts);
99		*pparts = NULL;
100		return -EINVAL;
101	}
102
103	return nr_parts;
104}
105
106static struct mtd_part_parser ofpart_parser = {
107	.owner = THIS_MODULE,
108	.parse_fn = parse_ofpart_partitions,
109	.name = "ofpart",
110};
111
112static int parse_ofoldpart_partitions(struct mtd_info *master,
113				      struct mtd_partition **pparts,
114				      struct mtd_part_parser_data *data)
115{
116	struct device_node *dp;
117	int i, plen, nr_parts;
118	const struct {
119		__be32 offset, len;
120	} *part;
121	const char *names;
122
123	if (!data)
124		return 0;
125
126	dp = data->of_node;
127	if (!dp)
128		return 0;
129
130	part = of_get_property(dp, "partitions", &plen);
131	if (!part)
132		return 0; /* No partitions found */
133
134	pr_warning("Device tree uses obsolete partition map binding: %s\n",
135			dp->full_name);
136
137	nr_parts = plen / sizeof(part[0]);
138
139	*pparts = kzalloc(nr_parts * sizeof(*(*pparts)), GFP_KERNEL);
140	if (!*pparts)
141		return -ENOMEM;
142
143	names = of_get_property(dp, "partition-names", &plen);
144
145	for (i = 0; i < nr_parts; i++) {
146		(*pparts)[i].offset = be32_to_cpu(part->offset);
147		(*pparts)[i].size   = be32_to_cpu(part->len) & ~1;
148		/* bit 0 set signifies read only partition */
149		if (be32_to_cpu(part->len) & 1)
150			(*pparts)[i].mask_flags = MTD_WRITEABLE;
151
152		if (names && (plen > 0)) {
153			int len = strlen(names) + 1;
154
155			(*pparts)[i].name = names;
156			plen -= len;
157			names += len;
158		} else {
159			(*pparts)[i].name = "unnamed";
160		}
161
162		part++;
163	}
164
165	return nr_parts;
166}
167
168static struct mtd_part_parser ofoldpart_parser = {
169	.owner = THIS_MODULE,
170	.parse_fn = parse_ofoldpart_partitions,
171	.name = "ofoldpart",
172};
173
174static int __init ofpart_parser_init(void)
175{
176	register_mtd_parser(&ofpart_parser);
177	register_mtd_parser(&ofoldpart_parser);
178	return 0;
179}
180
181static void __exit ofpart_parser_exit(void)
182{
183	deregister_mtd_parser(&ofpart_parser);
184	deregister_mtd_parser(&ofoldpart_parser);
185}
186
187module_init(ofpart_parser_init);
188module_exit(ofpart_parser_exit);
189
190MODULE_LICENSE("GPL");
191MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
192MODULE_AUTHOR("Vitaly Wool, David Gibson");
193/*
194 * When MTD core cannot find the requested parser, it tries to load the module
195 * with the same name. Since we provide the ofoldpart parser, we should have
196 * the corresponding alias.
197 */
198MODULE_ALIAS("ofoldpart");
199