2 * Flash mappings described by the OF (or flattened) device tree
4 * Copyright (C) 2006 MontaVista Software Inc.
5 * Author: Vitaly Wool <vwool@ru.mvista.com>
7 * Revised to handle newer style flash binding by:
8 * Copyright (C) 2007 David Gibson, IBM Corporation.
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.
16 #include <linux/module.h>
17 #include <linux/types.h>
18 #include <linux/init.h>
19 #include <linux/device.h>
20 #include <linux/mtd/mtd.h>
21 #include <linux/mtd/map.h>
22 #include <linux/mtd/partitions.h>
24 #include <linux/of_platform.h>
30 #ifdef CONFIG_MTD_PARTITIONS
31 struct mtd_partition *parts;
35 #ifdef CONFIG_MTD_PARTITIONS
36 #define OF_FLASH_PARTS(info) ((info)->parts)
38 static int parse_obsolete_partitions(struct of_device *dev,
39 struct of_flash *info,
40 struct device_node *dp)
42 int i, plen, nr_parts;
48 part = of_get_property(dp, "partitions", &plen);
50 return 0; /* No partitions found */
52 dev_warn(&dev->dev, "Device tree uses obsolete partition map binding\n");
54 nr_parts = plen / sizeof(part[0]);
56 info->parts = kzalloc(nr_parts * sizeof(*info->parts), GFP_KERNEL);
60 names = of_get_property(dp, "partition-names", &plen);
62 for (i = 0; i < nr_parts; i++) {
63 info->parts[i].offset = part->offset;
64 info->parts[i].size = part->len & ~1;
65 if (part->len & 1) /* bit 0 set signifies read only partition */
66 info->parts[i].mask_flags = MTD_WRITEABLE;
68 if (names && (plen > 0)) {
69 int len = strlen(names) + 1;
71 info->parts[i].name = (char *)names;
75 info->parts[i].name = "unnamed";
84 static int __devinit parse_partitions(struct of_flash *info,
85 struct of_device *dev)
88 static const char *part_probe_types[]
89 = { "cmdlinepart", "RedBoot", NULL };
90 struct device_node *dp = dev->node, *pp;
93 /* First look for RedBoot table or partitions on the command
94 * line, these take precedence over device tree information */
95 nr_parts = parse_mtd_partitions(info->mtd, part_probe_types,
98 add_mtd_partitions(info->mtd, info->parts, nr_parts);
102 /* First count the subnodes */
104 for (pp = dp->child; pp; pp = pp->sibling)
108 return parse_obsolete_partitions(dev, info, dp);
110 info->parts = kzalloc(nr_parts * sizeof(*info->parts),
115 for (pp = dp->child, i = 0; pp; pp = pp->sibling, i++) {
119 reg = of_get_property(pp, "reg", &len);
120 if (!reg || (len != 2*sizeof(u32))) {
121 dev_err(&dev->dev, "Invalid 'reg' on %s\n",
127 info->parts[i].offset = reg[0];
128 info->parts[i].size = reg[1];
130 partname = of_get_property(pp, "label", &len);
132 partname = of_get_property(pp, "name", &len);
133 info->parts[i].name = (char *)partname;
135 if (of_get_property(pp, "read-only", &len))
136 info->parts[i].mask_flags = MTD_WRITEABLE;
141 #else /* MTD_PARTITIONS */
142 #define OF_FLASH_PARTS(info) (0)
143 #define parse_partitions(info, dev) (0)
144 #endif /* MTD_PARTITIONS */
146 static int of_flash_remove(struct of_device *dev)
148 struct of_flash *info;
150 info = dev_get_drvdata(&dev->dev);
153 dev_set_drvdata(&dev->dev, NULL);
156 if (OF_FLASH_PARTS(info)) {
157 del_mtd_partitions(info->mtd);
158 kfree(OF_FLASH_PARTS(info));
160 del_mtd_device(info->mtd);
162 map_destroy(info->mtd);
166 iounmap(info->map.virt);
169 release_resource(info->res);
176 /* Helper function to handle probing of the obsolete "direct-mapped"
177 * compatible binding, which has an extra "probe-type" property
178 * describing the type of flash probe necessary. */
179 static struct mtd_info * __devinit obsolete_probe(struct of_device *dev,
180 struct map_info *map)
182 struct device_node *dp = dev->node;
183 const char *of_probe;
184 struct mtd_info *mtd;
185 static const char *rom_probe_types[]
186 = { "cfi_probe", "jedec_probe", "map_rom"};
189 dev_warn(&dev->dev, "Device tree uses obsolete \"direct-mapped\" "
192 of_probe = of_get_property(dp, "probe-type", NULL);
194 for (i = 0; i < ARRAY_SIZE(rom_probe_types); i++) {
195 mtd = do_map_probe(rom_probe_types[i], map);
200 } else if (strcmp(of_probe, "CFI") == 0) {
201 return do_map_probe("cfi_probe", map);
202 } else if (strcmp(of_probe, "JEDEC") == 0) {
203 return do_map_probe("jedec_probe", map);
205 if (strcmp(of_probe, "ROM") != 0)
206 dev_warn(&dev->dev, "obsolete_probe: don't know probe "
207 "type '%s', mapping as rom\n", of_probe);
208 return do_map_probe("mtd_rom", map);
212 static int __devinit of_flash_probe(struct of_device *dev,
213 const struct of_device_id *match)
215 struct device_node *dp = dev->node;
217 struct of_flash *info;
218 const char *probe_type = match->data;
223 if (of_address_to_resource(dp, 0, &res)) {
224 dev_err(&dev->dev, "Can't get IO address from device tree\n");
228 dev_dbg(&dev->dev, "of_flash device: %.8llx-%.8llx\n",
229 (unsigned long long)res.start, (unsigned long long)res.end);
232 info = kzalloc(sizeof(*info), GFP_KERNEL);
236 dev_set_drvdata(&dev->dev, info);
239 info->res = request_mem_region(res.start, res.end - res.start + 1,
245 width = of_get_property(dp, "bank-width", NULL);
247 dev_err(&dev->dev, "Can't get bank width from device tree\n");
251 info->map.name = dev->dev.bus_id;
252 info->map.phys = res.start;
253 info->map.size = res.end - res.start + 1;
254 info->map.bankwidth = *width;
257 info->map.virt = ioremap(info->map.phys, info->map.size);
258 if (!info->map.virt) {
259 dev_err(&dev->dev, "Failed to ioremap() flash region\n");
263 simple_map_init(&info->map);
266 info->mtd = do_map_probe(probe_type, &info->map);
268 info->mtd = obsolete_probe(dev, &info->map);
272 dev_err(&dev->dev, "do_map_probe() failed\n");
275 info->mtd->owner = THIS_MODULE;
277 err = parse_partitions(info, dev);
282 add_mtd_partitions(info->mtd, OF_FLASH_PARTS(info), err);
284 add_mtd_device(info->mtd);
289 of_flash_remove(dev);
293 static struct of_device_id of_flash_match[] = {
295 .compatible = "cfi-flash",
296 .data = (void *)"cfi_probe",
299 /* FIXME: JEDEC chips can't be safely and reliably
300 * probed, although the mtd code gets it right in
301 * practice most of the time. We should use the
302 * vendor and device ids specified by the binding to
303 * bypass the heuristic probe code, but the mtd layer
304 * provides, at present, no interface for doing so
306 .compatible = "jedec-flash",
307 .data = (void *)"jedec_probe",
311 .compatible = "direct-mapped"
315 MODULE_DEVICE_TABLE(of, of_flash_match);
317 static struct of_platform_driver of_flash_driver = {
319 .match_table = of_flash_match,
320 .probe = of_flash_probe,
321 .remove = of_flash_remove,
324 static int __init of_flash_init(void)
326 return of_register_platform_driver(&of_flash_driver);
329 static void __exit of_flash_exit(void)
331 of_unregister_platform_driver(&of_flash_driver);
334 module_init(of_flash_init);
335 module_exit(of_flash_exit);
337 MODULE_LICENSE("GPL");
338 MODULE_AUTHOR("Vitaly Wool <vwool@ru.mvista.com>");
339 MODULE_DESCRIPTION("Device tree based MTD map driver");