aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/mtd/maps/physmap_of.c
blob: 5fcfec034a9466819f83fb5ae00670e1c7fa976a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
/*
 * Flash mappings described by the OF (or flattened) device tree
 *
 * Copyright (C) 2006 MontaVista Software Inc.
 * Author: Vitaly Wool <vwool@ru.mvista.com>
 *
 * Revised to handle newer style flash binding by:
 *   Copyright (C) 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/types.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>
#include <linux/of.h>
#include <linux/of_platform.h>

struct of_flash {
	struct mtd_info		*mtd;
	struct map_info		map;
	struct resource		*res;
#ifdef CONFIG_MTD_PARTITIONS
	struct mtd_partition	*parts;
#endif
};

#ifdef CONFIG_MTD_PARTITIONS
#define OF_FLASH_PARTS(info)	((info)->parts)

static int parse_obsolete_partitions(struct of_device *dev,
				     struct of_flash *info,
				     struct device_node *dp)
{
	int i, plen, nr_parts;
	const struct {
		u32 offset, len;
	} *part;
	const char *names;

	part = of_get_property(dp, "partitions", &plen);
	if (!part)
		return 0; /* No partitions found */

	dev_warn(&dev->dev, "Device tree uses obsolete partition map binding\n");

	nr_parts = plen / sizeof(part[0]);

	info->parts = kzalloc(nr_parts * sizeof(*info->parts), GFP_KERNEL);
	if (!info->parts)
		return -ENOMEM;

	names = of_get_property(dp, "partition-names", &plen);

	for (i = 0; i < nr_parts; i++) {
		info->parts[i].offset = part->offset;
		info->parts[i].size   = part->len & ~1;
		if (part->len & 1) /* bit 0 set signifies read only partition */
			info->parts[i].mask_flags = MTD_WRITEABLE;

		if (names && (plen > 0)) {
			int len = strlen(names) + 1;

			info->parts[i].name = (char *)names;
			plen -= len;
			names += len;
		} else {
			info->parts[i].name = "unnamed";
		}

		part++;
	}

	return nr_parts;
}
#else /* MTD_PARTITIONS */
#define	OF_FLASH_PARTS(info)		(0)
#define parse_partitions(info, dev)	(0)
#endif /* MTD_PARTITIONS */

static int of_flash_remove(struct of_device *dev)
{
	struct of_flash *info;

	info = dev_get_drvdata(&dev->dev);
	if (!info)
		return 0;
	dev_set_drvdata(&dev->dev, NULL);

	if (info->mtd) {
		if (OF_FLASH_PARTS(info)) {
			del_mtd_partitions(info->mtd);
			kfree(OF_FLASH_PARTS(info));
		} else {
			del_mtd_device(info->mtd);
		}
		map_destroy(info->mtd);
	}

	if (info->map.virt)
		iounmap(info->map.virt);

	if (info->res) {
		release_resource(info->res);
		kfree(info->res);
	}

	return 0;
}

/* Helper function to handle probing of the obsolete "direct-mapped"
 * compatible binding, which has an extra "probe-type" property
 * describing the type of flash probe necessary. */
static struct mtd_info * __devinit obsolete_probe(struct of_device *dev,
						  struct map_info *map)
{
	struct device_node *dp = dev->node;
	const char *of_probe;
	struct mtd_info *mtd;
	static const char *rom_probe_types[]
		= { "cfi_probe", "jedec_probe", "map_rom"};
	int i;

	dev_warn(&dev->dev, "Device tree uses obsolete \"direct-mapped\" "
		 "flash binding\n");

	of_probe = of_get_property(dp, "probe-type", NULL);
	if (!of_probe) {
		for (i = 0; i < ARRAY_SIZE(rom_probe_types); i++) {
			mtd = do_map_probe(rom_probe_types[i], map);
			if (mtd)
				return mtd;
		}
		return NULL;
	} else if (strcmp(of_probe, "CFI") == 0) {
		return do_map_probe("cfi_probe", map);
	} else if (strcmp(of_probe, "JEDEC") == 0) {
		return do_map_probe("jedec_probe", map);
	} else {
		if (strcmp(of_probe, "ROM") != 0)
			dev_warn(&dev->dev, "obsolete_probe: don't know probe "
				 "type '%s', mapping as rom\n", of_probe);
		return do_map_probe("mtd_rom", map);
	}
}

static int __devinit of_flash_probe(struct of_device *dev,
				    const struct of_device_id *match)
{
#ifdef CONFIG_MTD_PARTITIONS
	static const char *part_probe_types[]
		= { "cmdlinepart", "RedBoot", NULL };
#endif
	struct device_node *dp = dev->node;
	struct resource res;
	struct of_flash *info;
	const char *probe_type = match->data;
	const u32 *width;
	int err;

	err = -ENXIO;
	if (of_address_to_resource(dp, 0, &res)) {
		dev_err(&dev->dev, "Can't get IO address from device tree\n");
		goto err_out;
	}

       	dev_dbg(&dev->dev, "of_flash device: %.8llx-%.8llx\n",
		(unsigned long long)res.start, (unsigned long long)res.end);

	err = -ENOMEM;
	info = kzalloc(sizeof(*info), GFP_KERNEL);
	if (!info)
		goto err_out;

	dev_set_drvdata(&dev->dev, info);

	err = -EBUSY;
	info->res = request_mem_region(res.start, res.end - res.start + 1,
				       dev->dev.bus_id);
	if (!info->res)
		goto err_out;

	err = -ENXIO;
	width = of_get_property(dp, "bank-width", NULL);
	if (!width) {
		dev_err(&dev->dev, "Can't get bank width from device tree\n");
		goto err_out;
	}

	info->map.name = dev->dev.bus_id;
	info->map.phys = res.start;
	info->map.size = res.end - res.start + 1;
	info->map.bankwidth = *width;

	err = -ENOMEM;
	info->map.virt = ioremap(info->map.phys, info->map.size);
	if (!info->map.virt) {
		dev_err(&dev->dev, "Failed to ioremap() flash region\n");
		goto err_out;
	}

	simple_map_init(&info->map);

	if (probe_type)
		info->mtd = do_map_probe(probe_type, &info->map);
	else
		info->mtd = obsolete_probe(dev, &info->map);

	err = -ENXIO;
	if (!info->mtd) {
		dev_err(&dev->dev, "do_map_probe() failed\n");
		goto err_out;
	}
	info->mtd->owner = THIS_MODULE;

#ifdef CONFIG_MTD_PARTITIONS
	/* First look for RedBoot table or partitions on the command
	 * line, these take precedence over device tree information */
	err = parse_mtd_partitions(info->mtd, part_probe_types,
	                           &info->parts, 0);
	if (err < 0)
		return err;

#ifdef CONFIG_MTD_OF_PARTS
	if (err == 0) {
		err = of_mtd_parse_partitions(&dev->dev, dp, &info->parts);
		if (err < 0)
			return err;
	}
#endif

	if (err == 0) {
		err = parse_obsolete_partitions(dev, info, dp);
		if (err < 0)
			return err;
	}

	if (err > 0)
		add_mtd_partitions(info->mtd, info->parts, err);
	else
#endif
		add_mtd_device(info->mtd);

	return 0;

err_out:
	of_flash_remove(dev);
	return err;
}

static struct of_device_id of_flash_match[] = {
	{
		.compatible	= "cfi-flash",
		.data		= (void *)"cfi_probe",
	},
	{
		/* FIXME: JEDEC chips can't be safely and reliably
		 * probed, although the mtd code gets it right in
		 * practice most of the time.  We should use the
		 * vendor and device ids specified by the binding to
		 * bypass the heuristic probe code, but the mtd layer
		 * provides, at present, no interface for doing so
		 * :(. */
		.compatible	= "jedec-flash",
		.data		= (void *)"jedec_probe",
	},
	{
		.type		= "rom",
		.compatible	= "direct-mapped"
	},
	{ },
};
MODULE_DEVICE_TABLE(of, of_flash_match);

static struct of_platform_driver of_flash_driver = {
	.name		= "of-flash",
	.match_table	= of_flash_match,
	.probe		= of_flash_probe,
	.remove		= of_flash_remove,
};

static int __init of_flash_init(void)
{
	return of_register_platform_driver(&of_flash_driver);
}

static void __exit of_flash_exit(void)
{
	of_unregister_platform_driver(&of_flash_driver);
}

module_init(of_flash_init);
module_exit(of_flash_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Vitaly Wool <vwool@ru.mvista.com>");
MODULE_DESCRIPTION("Device tree based MTD map driver");