1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Flash partitions described by the OF (or flattened) device tree
4 *
5 * Copyright �� 2006 MontaVista Software Inc.
6 * Author: Vitaly Wool <vwool@ru.mvista.com>
7 *
8 * Revised to handle newer style flash binding by:
9 *   Copyright �� 2007 David Gibson, IBM Corporation.
10 */
11
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/of.h>
15#include <linux/mtd/mtd.h>
16#include <linux/slab.h>
17#include <linux/mtd/partitions.h>
18
19#include "ofpart_bcm4908.h"
20#include "ofpart_linksys_ns.h"
21
22struct fixed_partitions_quirks {
23	int (*post_parse)(struct mtd_info *mtd, struct mtd_partition *parts, int nr_parts);
24};
25
26static struct fixed_partitions_quirks bcm4908_partitions_quirks = {
27	.post_parse = bcm4908_partitions_post_parse,
28};
29
30static struct fixed_partitions_quirks linksys_ns_partitions_quirks = {
31	.post_parse = linksys_ns_partitions_post_parse,
32};
33
34static const struct of_device_id parse_ofpart_match_table[];
35
36static bool node_has_compatible(struct device_node *pp)
37{
38	return of_get_property(pp, "compatible", NULL);
39}
40
41static int parse_fixed_partitions(struct mtd_info *master,
42				  const struct mtd_partition **pparts,
43				  struct mtd_part_parser_data *data)
44{
45	const struct fixed_partitions_quirks *quirks;
46	const struct of_device_id *of_id;
47	struct mtd_partition *parts;
48	struct device_node *mtd_node;
49	struct device_node *ofpart_node;
50	const char *partname;
51	struct device_node *pp;
52	int nr_parts, i, ret = 0;
53	bool dedicated = true;
54
55	/* Pull of_node from the master device node */
56	mtd_node = mtd_get_of_node(master);
57	if (!mtd_node)
58		return 0;
59
60	if (!master->parent) { /* Master */
61		ofpart_node = of_get_child_by_name(mtd_node, "partitions");
62		if (!ofpart_node) {
63			/*
64			 * We might get here even when ofpart isn't used at all (e.g.,
65			 * when using another parser), so don't be louder than
66			 * KERN_DEBUG
67			 */
68			pr_debug("%s: 'partitions' subnode not found on %pOF. Trying to parse direct subnodes as partitions.\n",
69				master->name, mtd_node);
70			ofpart_node = mtd_node;
71			dedicated = false;
72		}
73	} else { /* Partition */
74		ofpart_node = mtd_node;
75	}
76
77	of_id = of_match_node(parse_ofpart_match_table, ofpart_node);
78	if (dedicated && !of_id) {
79		/* The 'partitions' subnode might be used by another parser */
80		return 0;
81	}
82
83	quirks = of_id ? of_id->data : NULL;
84
85	/* First count the subnodes */
86	nr_parts = 0;
87	for_each_child_of_node(ofpart_node,  pp) {
88		if (!dedicated && node_has_compatible(pp))
89			continue;
90
91		nr_parts++;
92	}
93
94	if (nr_parts == 0)
95		return 0;
96
97	parts = kcalloc(nr_parts, sizeof(*parts), GFP_KERNEL);
98	if (!parts)
99		return -ENOMEM;
100
101	i = 0;
102	for_each_child_of_node(ofpart_node,  pp) {
103		const __be32 *reg;
104		int len;
105		int a_cells, s_cells;
106
107		if (!dedicated && node_has_compatible(pp))
108			continue;
109
110		reg = of_get_property(pp, "reg", &len);
111		if (!reg) {
112			if (dedicated) {
113				pr_debug("%s: ofpart partition %pOF (%pOF) missing reg property.\n",
114					 master->name, pp,
115					 mtd_node);
116				goto ofpart_fail;
117			} else {
118				nr_parts--;
119				continue;
120			}
121		}
122
123		a_cells = of_n_addr_cells(pp);
124		s_cells = of_n_size_cells(pp);
125		if (!dedicated && s_cells == 0) {
126			/*
127			 * This is a ugly workaround to not create
128			 * regression on devices that are still creating
129			 * partitions as direct children of the nand controller.
130			 * This can happen in case the nand controller node has
131			 * #size-cells equal to 0 and the firmware (e.g.
132			 * U-Boot) just add the partitions there assuming
133			 * 32-bit addressing.
134			 *
135			 * If you get this warning your firmware and/or DTS
136			 * should be really fixed.
137			 *
138			 * This is working only for devices smaller than 4GiB.
139			 */
140			pr_warn("%s: ofpart partition %pOF (%pOF) #size-cells is wrongly set to <0>, assuming <1> for parsing partitions.\n",
141				master->name, pp, mtd_node);
142			s_cells = 1;
143		}
144		if (len / 4 != a_cells + s_cells) {
145			pr_debug("%s: ofpart partition %pOF (%pOF) error parsing reg property.\n",
146				 master->name, pp,
147				 mtd_node);
148			goto ofpart_fail;
149		}
150
151		parts[i].offset = of_read_number(reg, a_cells);
152		parts[i].size = of_read_number(reg + a_cells, s_cells);
153		parts[i].of_node = pp;
154
155		partname = of_get_property(pp, "label", &len);
156		if (!partname)
157			partname = of_get_property(pp, "name", &len);
158		parts[i].name = partname;
159
160		if (of_get_property(pp, "read-only", &len))
161			parts[i].mask_flags |= MTD_WRITEABLE;
162
163		if (of_get_property(pp, "lock", &len))
164			parts[i].mask_flags |= MTD_POWERUP_LOCK;
165
166		if (of_property_read_bool(pp, "slc-mode"))
167			parts[i].add_flags |= MTD_SLC_ON_MLC_EMULATION;
168
169		i++;
170	}
171
172	if (!nr_parts)
173		goto ofpart_none;
174
175	if (quirks && quirks->post_parse)
176		quirks->post_parse(master, parts, nr_parts);
177
178	*pparts = parts;
179	return nr_parts;
180
181ofpart_fail:
182	pr_err("%s: error parsing ofpart partition %pOF (%pOF)\n",
183	       master->name, pp, mtd_node);
184	ret = -EINVAL;
185ofpart_none:
186	of_node_put(pp);
187	kfree(parts);
188	return ret;
189}
190
191static const struct of_device_id parse_ofpart_match_table[] = {
192	/* Generic */
193	{ .compatible = "fixed-partitions" },
194	/* Customized */
195	{ .compatible = "brcm,bcm4908-partitions", .data = &bcm4908_partitions_quirks, },
196	{ .compatible = "linksys,ns-partitions", .data = &linksys_ns_partitions_quirks, },
197	{},
198};
199MODULE_DEVICE_TABLE(of, parse_ofpart_match_table);
200
201static struct mtd_part_parser ofpart_parser = {
202	.parse_fn = parse_fixed_partitions,
203	.name = "fixed-partitions",
204	.of_match_table = parse_ofpart_match_table,
205};
206
207static int parse_ofoldpart_partitions(struct mtd_info *master,
208				      const struct mtd_partition **pparts,
209				      struct mtd_part_parser_data *data)
210{
211	struct mtd_partition *parts;
212	struct device_node *dp;
213	int i, plen, nr_parts;
214	const struct {
215		__be32 offset, len;
216	} *part;
217	const char *names;
218
219	/* Pull of_node from the master device node */
220	dp = mtd_get_of_node(master);
221	if (!dp)
222		return 0;
223
224	part = of_get_property(dp, "partitions", &plen);
225	if (!part)
226		return 0; /* No partitions found */
227
228	pr_warn("Device tree uses obsolete partition map binding: %pOF\n", dp);
229
230	nr_parts = plen / sizeof(part[0]);
231
232	parts = kcalloc(nr_parts, sizeof(*parts), GFP_KERNEL);
233	if (!parts)
234		return -ENOMEM;
235
236	names = of_get_property(dp, "partition-names", &plen);
237
238	for (i = 0; i < nr_parts; i++) {
239		parts[i].offset = be32_to_cpu(part->offset);
240		parts[i].size   = be32_to_cpu(part->len) & ~1;
241		/* bit 0 set signifies read only partition */
242		if (be32_to_cpu(part->len) & 1)
243			parts[i].mask_flags = MTD_WRITEABLE;
244
245		if (names && (plen > 0)) {
246			int len = strlen(names) + 1;
247
248			parts[i].name = names;
249			plen -= len;
250			names += len;
251		} else {
252			parts[i].name = "unnamed";
253		}
254
255		part++;
256	}
257
258	*pparts = parts;
259	return nr_parts;
260}
261
262static struct mtd_part_parser ofoldpart_parser = {
263	.parse_fn = parse_ofoldpart_partitions,
264	.name = "ofoldpart",
265};
266
267static int __init ofpart_parser_init(void)
268{
269	register_mtd_parser(&ofpart_parser);
270	register_mtd_parser(&ofoldpart_parser);
271	return 0;
272}
273
274static void __exit ofpart_parser_exit(void)
275{
276	deregister_mtd_parser(&ofpart_parser);
277	deregister_mtd_parser(&ofoldpart_parser);
278}
279
280module_init(ofpart_parser_init);
281module_exit(ofpart_parser_exit);
282
283MODULE_LICENSE("GPL");
284MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
285MODULE_AUTHOR("Vitaly Wool, David Gibson");
286/*
287 * When MTD core cannot find the requested parser, it tries to load the module
288 * with the same name. Since we provide the ofoldpart parser, we should have
289 * the corresponding alias.
290 */
291MODULE_ALIAS("fixed-partitions");
292MODULE_ALIAS("ofoldpart");
293