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 *mtd_node;
33	struct device_node *ofpart_node;
34	const char *partname;
35	struct device_node *pp;
36	int nr_parts, i, ret = 0;
37	bool dedicated = true;
38
39
40	if (!data)
41		return 0;
42
43	mtd_node = data->of_node;
44	if (!mtd_node)
45		return 0;
46
47	ofpart_node = of_get_child_by_name(mtd_node, "partitions");
48	if (!ofpart_node) {
49		/*
50		 * We might get here even when ofpart isn't used at all (e.g.,
51		 * when using another parser), so don't be louder than
52		 * KERN_DEBUG
53		 */
54		pr_debug("%s: 'partitions' subnode not found on %s. Trying to parse direct subnodes as partitions.\n",
55			 master->name, mtd_node->full_name);
56		ofpart_node = mtd_node;
57		dedicated = false;
58	} else if (!of_device_is_compatible(ofpart_node, "fixed-partitions")) {
59		/* The 'partitions' subnode might be used by another parser */
60		return 0;
61	}
62
63	/* First count the subnodes */
64	nr_parts = 0;
65	for_each_child_of_node(ofpart_node,  pp) {
66		if (!dedicated && node_has_compatible(pp))
67			continue;
68
69		nr_parts++;
70	}
71
72	if (nr_parts == 0)
73		return 0;
74
75	*pparts = kzalloc(nr_parts * sizeof(**pparts), GFP_KERNEL);
76	if (!*pparts)
77		return -ENOMEM;
78
79	i = 0;
80	for_each_child_of_node(ofpart_node,  pp) {
81		const __be32 *reg;
82		int len;
83		int a_cells, s_cells;
84
85		if (!dedicated && node_has_compatible(pp))
86			continue;
87
88		reg = of_get_property(pp, "reg", &len);
89		if (!reg) {
90			if (dedicated) {
91				pr_debug("%s: ofpart partition %s (%s) missing reg property.\n",
92					 master->name, pp->full_name,
93					 mtd_node->full_name);
94				goto ofpart_fail;
95			} else {
96				nr_parts--;
97				continue;
98			}
99		}
100
101		a_cells = of_n_addr_cells(pp);
102		s_cells = of_n_size_cells(pp);
103		if (len / 4 != a_cells + s_cells) {
104			pr_debug("%s: ofpart partition %s (%s) error parsing reg property.\n",
105				 master->name, pp->full_name,
106				 mtd_node->full_name);
107			goto ofpart_fail;
108		}
109
110		(*pparts)[i].offset = of_read_number(reg, a_cells);
111		(*pparts)[i].size = of_read_number(reg + a_cells, s_cells);
112
113		partname = of_get_property(pp, "label", &len);
114		if (!partname)
115			partname = of_get_property(pp, "name", &len);
116		(*pparts)[i].name = partname;
117
118		if (of_get_property(pp, "read-only", &len))
119			(*pparts)[i].mask_flags |= MTD_WRITEABLE;
120
121		if (of_get_property(pp, "lock", &len))
122			(*pparts)[i].mask_flags |= MTD_POWERUP_LOCK;
123
124		i++;
125	}
126
127	if (!nr_parts)
128		goto ofpart_none;
129
130	return nr_parts;
131
132ofpart_fail:
133	pr_err("%s: error parsing ofpart partition %s (%s)\n",
134	       master->name, pp->full_name, mtd_node->full_name);
135	ret = -EINVAL;
136ofpart_none:
137	of_node_put(pp);
138	kfree(*pparts);
139	*pparts = NULL;
140	return ret;
141}
142
143static struct mtd_part_parser ofpart_parser = {
144	.owner = THIS_MODULE,
145	.parse_fn = parse_ofpart_partitions,
146	.name = "ofpart",
147};
148
149static int parse_ofoldpart_partitions(struct mtd_info *master,
150				      struct mtd_partition **pparts,
151				      struct mtd_part_parser_data *data)
152{
153	struct device_node *dp;
154	int i, plen, nr_parts;
155	const struct {
156		__be32 offset, len;
157	} *part;
158	const char *names;
159
160	if (!data)
161		return 0;
162
163	dp = data->of_node;
164	if (!dp)
165		return 0;
166
167	part = of_get_property(dp, "partitions", &plen);
168	if (!part)
169		return 0; /* No partitions found */
170
171	pr_warning("Device tree uses obsolete partition map binding: %s\n",
172			dp->full_name);
173
174	nr_parts = plen / sizeof(part[0]);
175
176	*pparts = kzalloc(nr_parts * sizeof(*(*pparts)), GFP_KERNEL);
177	if (!*pparts)
178		return -ENOMEM;
179
180	names = of_get_property(dp, "partition-names", &plen);
181
182	for (i = 0; i < nr_parts; i++) {
183		(*pparts)[i].offset = be32_to_cpu(part->offset);
184		(*pparts)[i].size   = be32_to_cpu(part->len) & ~1;
185		/* bit 0 set signifies read only partition */
186		if (be32_to_cpu(part->len) & 1)
187			(*pparts)[i].mask_flags = MTD_WRITEABLE;
188
189		if (names && (plen > 0)) {
190			int len = strlen(names) + 1;
191
192			(*pparts)[i].name = names;
193			plen -= len;
194			names += len;
195		} else {
196			(*pparts)[i].name = "unnamed";
197		}
198
199		part++;
200	}
201
202	return nr_parts;
203}
204
205static struct mtd_part_parser ofoldpart_parser = {
206	.owner = THIS_MODULE,
207	.parse_fn = parse_ofoldpart_partitions,
208	.name = "ofoldpart",
209};
210
211static int __init ofpart_parser_init(void)
212{
213	register_mtd_parser(&ofpart_parser);
214	register_mtd_parser(&ofoldpart_parser);
215	return 0;
216}
217
218static void __exit ofpart_parser_exit(void)
219{
220	deregister_mtd_parser(&ofpart_parser);
221	deregister_mtd_parser(&ofoldpart_parser);
222}
223
224module_init(ofpart_parser_init);
225module_exit(ofpart_parser_exit);
226
227MODULE_LICENSE("GPL");
228MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
229MODULE_AUTHOR("Vitaly Wool, David Gibson");
230/*
231 * When MTD core cannot find the requested parser, it tries to load the module
232 * with the same name. Since we provide the ofoldpart parser, we should have
233 * the corresponding alias.
234 */
235MODULE_ALIAS("ofoldpart");
236