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/device.h>
19 #include <linux/mtd/mtd.h>
20 #include <linux/mtd/map.h>
21 #include <linux/mtd/partitions.h>
22 #include <linux/mtd/concat.h>
23 #include <linux/mtd/cfi_endian.h>
25 #include <linux/of_address.h>
26 #include <linux/of_platform.h>
27 #include <linux/slab.h>
28 #include "physmap_of_gemini.h"
29 #include "physmap_of_versatile.h"
31 struct of_flash_list {
38 struct mtd_info *cmtd;
39 int list_size; /* number of elements in of_flash_list */
40 struct of_flash_list list[0];
43 static int of_flash_remove(struct platform_device *dev)
45 struct of_flash *info;
48 info = dev_get_drvdata(&dev->dev);
51 dev_set_drvdata(&dev->dev, NULL);
54 mtd_device_unregister(info->cmtd);
55 if (info->cmtd != info->list[0].mtd)
56 mtd_concat_destroy(info->cmtd);
59 for (i = 0; i < info->list_size; i++) {
60 if (info->list[i].mtd)
61 map_destroy(info->list[i].mtd);
63 if (info->list[i].map.virt)
64 iounmap(info->list[i].map.virt);
66 if (info->list[i].res) {
67 release_resource(info->list[i].res);
68 kfree(info->list[i].res);
74 static const char * const rom_probe_types[] = {
75 "cfi_probe", "jedec_probe", "map_rom" };
77 /* Helper function to handle probing of the obsolete "direct-mapped"
78 * compatible binding, which has an extra "probe-type" property
79 * describing the type of flash probe necessary. */
80 static struct mtd_info *obsolete_probe(struct platform_device *dev,
83 struct device_node *dp = dev->dev.of_node;
88 dev_warn(&dev->dev, "Device tree uses obsolete \"direct-mapped\" "
91 of_probe = of_get_property(dp, "probe-type", NULL);
93 for (i = 0; i < ARRAY_SIZE(rom_probe_types); i++) {
94 mtd = do_map_probe(rom_probe_types[i], map);
99 } else if (strcmp(of_probe, "CFI") == 0) {
100 return do_map_probe("cfi_probe", map);
101 } else if (strcmp(of_probe, "JEDEC") == 0) {
102 return do_map_probe("jedec_probe", map);
104 if (strcmp(of_probe, "ROM") != 0)
105 dev_warn(&dev->dev, "obsolete_probe: don't know probe "
106 "type '%s', mapping as rom\n", of_probe);
107 return do_map_probe("map_rom", map);
111 /* When partitions are set we look for a linux,part-probe property which
112 specifies the list of partition probers to use. If none is given then the
113 default is use. These take precedence over other device tree
115 static const char * const part_probe_types_def[] = {
116 "cmdlinepart", "RedBoot", "ofpart", "ofoldpart", NULL };
118 static const char * const *of_get_probes(struct device_node *dp)
123 count = of_property_count_strings(dp, "linux,part-probe");
125 return part_probe_types_def;
127 res = kcalloc(count + 1, sizeof(*res), GFP_KERNEL);
131 count = of_property_read_string_array(dp, "linux,part-probe", res,
139 static void of_free_probes(const char * const *probes)
141 if (probes != part_probe_types_def)
145 static const struct of_device_id of_flash_match[];
146 static int of_flash_probe(struct platform_device *dev)
148 const char * const *part_probe_types;
149 const struct of_device_id *match;
150 struct device_node *dp = dev->dev.of_node;
152 struct of_flash *info;
153 const char *probe_type;
160 struct mtd_info **mtd_list = NULL;
161 resource_size_t res_size;
163 const char *mtd_name = NULL;
165 match = of_match_device(of_flash_match, &dev->dev);
168 probe_type = match->data;
170 reg_tuple_size = (of_n_addr_cells(dp) + of_n_size_cells(dp)) * sizeof(u32);
172 of_property_read_string(dp, "linux,mtd-name", &mtd_name);
175 * Get number of "reg" tuples. Scan for MTD devices on area's
176 * described by each "reg" region. This makes it possible (including
177 * the concat support) to support the Intel P30 48F4400 chips which
178 * consists internally of 2 non-identical NOR chips on one die.
180 p = of_get_property(dp, "reg", &count);
181 if (!p || count % reg_tuple_size != 0) {
182 dev_err(&dev->dev, "Malformed reg property on %pOF\n",
185 goto err_flash_remove;
187 count /= reg_tuple_size;
189 map_indirect = of_property_read_bool(dp, "no-unaligned-direct-access");
192 info = devm_kzalloc(&dev->dev,
193 sizeof(struct of_flash) +
194 sizeof(struct of_flash_list) * count, GFP_KERNEL);
196 goto err_flash_remove;
198 dev_set_drvdata(&dev->dev, info);
200 mtd_list = kcalloc(count, sizeof(*mtd_list), GFP_KERNEL);
202 goto err_flash_remove;
204 for (i = 0; i < count; i++) {
206 if (of_address_to_resource(dp, i, &res)) {
208 * Continue with next register tuple if this
209 * one is not mappable
214 dev_dbg(&dev->dev, "of_flash device: %pR\n", &res);
217 res_size = resource_size(&res);
218 info->list[i].res = request_mem_region(res.start, res_size,
219 dev_name(&dev->dev));
220 if (!info->list[i].res)
224 width = of_get_property(dp, "bank-width", NULL);
226 dev_err(&dev->dev, "Can't get bank width from device"
231 info->list[i].map.name = mtd_name ?: dev_name(&dev->dev);
232 info->list[i].map.phys = res.start;
233 info->list[i].map.size = res_size;
234 info->list[i].map.bankwidth = be32_to_cpup(width);
235 info->list[i].map.device_node = dp;
237 if (of_property_read_bool(dp, "big-endian"))
238 info->list[i].map.swap = CFI_BIG_ENDIAN;
239 else if (of_property_read_bool(dp, "little-endian"))
240 info->list[i].map.swap = CFI_LITTLE_ENDIAN;
242 err = of_flash_probe_gemini(dev, dp, &info->list[i].map);
245 err = of_flash_probe_versatile(dev, dp, &info->list[i].map);
250 info->list[i].map.virt = ioremap(info->list[i].map.phys,
251 info->list[i].map.size);
252 if (!info->list[i].map.virt) {
253 dev_err(&dev->dev, "Failed to ioremap() flash"
258 simple_map_init(&info->list[i].map);
261 * On some platforms (e.g. MPC5200) a direct 1:1 mapping
262 * may cause problems with JFFS2 usage, as the local bus (LPB)
263 * doesn't support unaligned accesses as implemented in the
264 * JFFS2 code via memcpy(). By setting NO_XIP, the
265 * flash will not be exposed directly to the MTD users
266 * (e.g. JFFS2) any more.
269 info->list[i].map.phys = NO_XIP;
272 info->list[i].mtd = do_map_probe(probe_type,
275 info->list[i].mtd = obsolete_probe(dev,
279 /* Fall back to mapping region as ROM */
280 if (!info->list[i].mtd) {
282 "do_map_probe() failed for type %s\n",
285 info->list[i].mtd = do_map_probe("map_rom",
288 mtd_list[i] = info->list[i].mtd;
291 if (!info->list[i].mtd) {
292 dev_err(&dev->dev, "do_map_probe() failed\n");
297 info->list[i].mtd->dev.parent = &dev->dev;
302 if (info->list_size == 1) {
303 info->cmtd = info->list[0].mtd;
304 } else if (info->list_size > 1) {
306 * We detected multiple devices. Concatenate them together.
308 info->cmtd = mtd_concat_create(mtd_list, info->list_size,
309 dev_name(&dev->dev));
311 if (info->cmtd == NULL)
317 info->cmtd->dev.parent = &dev->dev;
318 mtd_set_of_node(info->cmtd, dp);
319 part_probe_types = of_get_probes(dp);
320 if (!part_probe_types) {
324 mtd_device_parse_register(info->cmtd, part_probe_types, NULL,
326 of_free_probes(part_probe_types);
335 of_flash_remove(dev);
340 static const struct of_device_id of_flash_match[] = {
342 .compatible = "cfi-flash",
343 .data = (void *)"cfi_probe",
346 /* FIXME: JEDEC chips can't be safely and reliably
347 * probed, although the mtd code gets it right in
348 * practice most of the time. We should use the
349 * vendor and device ids specified by the binding to
350 * bypass the heuristic probe code, but the mtd layer
351 * provides, at present, no interface for doing so
353 .compatible = "jedec-flash",
354 .data = (void *)"jedec_probe",
357 .compatible = "mtd-ram",
358 .data = (void *)"map_ram",
361 .compatible = "mtd-rom",
362 .data = (void *)"map_rom",
366 .compatible = "direct-mapped"
370 MODULE_DEVICE_TABLE(of, of_flash_match);
372 static struct platform_driver of_flash_driver = {
375 .of_match_table = of_flash_match,
377 .probe = of_flash_probe,
378 .remove = of_flash_remove,
381 module_platform_driver(of_flash_driver);
383 MODULE_LICENSE("GPL");
384 MODULE_AUTHOR("Vitaly Wool <vwool@ru.mvista.com>");
385 MODULE_DESCRIPTION("Device tree based MTD map driver");