summaryrefslogtreecommitdiffstats
path: root/drivers/mtd/maps/physmap_of.c
blob: 70c453144f0018bef1b5abb4bdec764df7e38348 (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
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
/*
 * 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/device.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>
#include <linux/mtd/concat.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/slab.h>

struct of_flash_list {
	struct mtd_info *mtd;
	struct map_info map;
	struct resource *res;
};

struct of_flash {
	struct mtd_info		*cmtd;
	int list_size; /* number of elements in of_flash_list */
	struct of_flash_list	list[0];
};

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

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

	if (info->cmtd) {
		mtd_device_unregister(info->cmtd);
		if (info->cmtd != info->list[0].mtd)
			mtd_concat_destroy(info->cmtd);
	}

	for (i = 0; i < info->list_size; i++) {
		if (info->list[i].mtd)
			map_destroy(info->list[i].mtd);

		if (info->list[i].map.virt)
			iounmap(info->list[i].map.virt);

		if (info->list[i].res) {
			release_resource(info->list[i].res);
			kfree(info->list[i].res);
		}
	}
	return 0;
}

static const char * const rom_probe_types[] = {
	"cfi_probe", "jedec_probe", "map_rom" };

/* 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 *obsolete_probe(struct platform_device *dev,
				       struct map_info *map)
{
	struct device_node *dp = dev->dev.of_node;
	const char *of_probe;
	struct mtd_info *mtd;
	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("map_rom", map);
	}
}

/* When partitions are set we look for a linux,part-probe property which
   specifies the list of partition probers to use. If none is given then the
   default is use. These take precedence over other device tree
   information. */
static const char * const part_probe_types_def[] = {
	"cmdlinepart", "RedBoot", "ofpart", "ofoldpart", NULL };

static const char * const *of_get_probes(struct device_node *dp)
{
	const char *cp;
	int cplen;
	unsigned int l;
	unsigned int count;
	const char **res;

	cp = of_get_property(dp, "linux,part-probe", &cplen);
	if (cp == NULL)
		return part_probe_types_def;

	count = 0;
	for (l = 0; l != cplen; l++)
		if (cp[l] == 0)
			count++;

	res = kzalloc((count + 1)*sizeof(*res), GFP_KERNEL);
	if (!res)
		return NULL;
	count = 0;
	while (cplen > 0) {
		res[count] = cp;
		l = strlen(cp) + 1;
		cp += l;
		cplen -= l;
		count++;
	}
	return res;
}

static void of_free_probes(const char * const *probes)
{
	if (probes != part_probe_types_def)
		kfree(probes);
}

static const struct of_device_id of_flash_match[];
static int of_flash_probe(struct platform_device *dev)
{
	const char * const *part_probe_types;
	const struct of_device_id *match;
	struct device_node *dp = dev->dev.of_node;
	struct resource res;
	struct of_flash *info;
	const char *probe_type;
	const __be32 *width;
	int err;
	int i;
	int count;
	const __be32 *p;
	int reg_tuple_size;
	struct mtd_info **mtd_list = NULL;
	resource_size_t res_size;
	bool map_indirect;
	const char *mtd_name = NULL;

	match = of_match_device(of_flash_match, &dev->dev);
	if (!match)
		return -EINVAL;
	probe_type = match->data;

	reg_tuple_size = (of_n_addr_cells(dp) + of_n_size_cells(dp)) * sizeof(u32);

	of_property_read_string(dp, "linux,mtd-name", &mtd_name);

	/*
	 * Get number of "reg" tuples. Scan for MTD devices on area's
	 * described by each "reg" region. This makes it possible (including
	 * the concat support) to support the Intel P30 48F4400 chips which
	 * consists internally of 2 non-identical NOR chips on one die.
	 */
	p = of_get_property(dp, "reg", &count);
	if (count % reg_tuple_size != 0) {
		dev_err(&dev->dev, "Malformed reg property on %s\n",
				dev->dev.of_node->full_name);
		err = -EINVAL;
		goto err_flash_remove;
	}
	count /= reg_tuple_size;

	map_indirect = of_property_read_bool(dp, "no-unaligned-direct-access");

	err = -ENOMEM;
	info = devm_kzalloc(&dev->dev,
			    sizeof(struct of_flash) +
			    sizeof(struct of_flash_list) * count, GFP_KERNEL);
	if (!info)
		goto err_flash_remove;

	dev_set_drvdata(&dev->dev, info);

	mtd_list = kzalloc(sizeof(*mtd_list) * count, GFP_KERNEL);
	if (!mtd_list)
		goto err_flash_remove;

	for (i = 0; i < count; i++) {
		err = -ENXIO;
		if (of_address_to_resource(dp, i, &res)) {
			/*
			 * Continue with next register tuple if this
			 * one is not mappable
			 */
			continue;
		}

		dev_dbg(&dev->dev, "of_flash device: %pR\n", &res);

		err = -EBUSY;
		res_size = resource_size(&res);
		info->list[i].res = request_mem_region(res.start, res_size,
						       dev_name(&dev->dev));
		if (!info->list[i].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->list[i].map.name = mtd_name ?: dev_name(&dev->dev);
		info->list[i].map.phys = res.start;
		info->list[i].map.size = res_size;
		info->list[i].map.bankwidth = be32_to_cpup(width);
		info->list[i].map.device_node = dp;

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

		simple_map_init(&info->list[i].map);

		/*
		 * On some platforms (e.g. MPC5200) a direct 1:1 mapping
		 * may cause problems with JFFS2 usage, as the local bus (LPB)
		 * doesn't support unaligned accesses as implemented in the
		 * JFFS2 code via memcpy(). By setting NO_XIP, the
		 * flash will not be exposed directly to the MTD users
		 * (e.g. JFFS2) any more.
		 */
		if (map_indirect)
			info->list[i].map.phys = NO_XIP;

		if (probe_type) {
			info->list[i].mtd = do_map_probe(probe_type,
							 &info->list[i].map);
		} else {
			info->list[i].mtd = obsolete_probe(dev,
							   &info->list[i].map);
		}

		/* Fall back to mapping region as ROM */
		if (!info->list[i].mtd) {
			dev_warn(&dev->dev,
				"do_map_probe() failed for type %s\n",
				 probe_type);

			info->list[i].mtd = do_map_probe("map_rom",
							 &info->list[i].map);
		}
		mtd_list[i] = info->list[i].mtd;

		err = -ENXIO;
		if (!info->list[i].mtd) {
			dev_err(&dev->dev, "do_map_probe() failed\n");
			goto err_out;
		} else {
			info->list_size++;
		}
		info->list[i].mtd->dev.parent = &dev->dev;
	}

	err = 0;
	info->cmtd = NULL;
	if (info->list_size == 1) {
		info->cmtd = info->list[0].mtd;
	} else if (info->list_size > 1) {
		/*
		 * We detected multiple devices. Concatenate them together.
		 */
		info->cmtd = mtd_concat_create(mtd_list, info->list_size,
					       dev_name(&dev->dev));
	}
	if (info->cmtd == NULL)
		err = -ENXIO;

	if (err)
		goto err_out;

	info->cmtd->dev.parent = &dev->dev;
	mtd_set_of_node(info->cmtd, dp);
	part_probe_types = of_get_probes(dp);
	if (!part_probe_types) {
		err = -ENOMEM;
		goto err_out;
	}
	mtd_device_parse_register(info->cmtd, part_probe_types, NULL,
			NULL, 0);
	of_free_probes(part_probe_types);

	kfree(mtd_list);

	return 0;

err_out:
	kfree(mtd_list);
err_flash_remove:
	of_flash_remove(dev);

	return err;
}

static const 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",
	},
	{
		.compatible     = "mtd-ram",
		.data           = (void *)"map_ram",
	},
	{
		.compatible     = "mtd-rom",
		.data           = (void *)"map_rom",
	},
	{
		.type		= "rom",
		.compatible	= "direct-mapped"
	},
	{ },
};
MODULE_DEVICE_TABLE(of, of_flash_match);

static struct platform_driver of_flash_driver = {
	.driver = {
		.name = "of-flash",
		.of_match_table = of_flash_match,
	},
	.probe		= of_flash_probe,
	.remove		= of_flash_remove,
};

module_platform_driver(of_flash_driver);

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