- 根目录:
- drivers
- mtd
- maps
- physmap_of.c
/*
* 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/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 != info->list[0].mtd) {
mtd_device_unregister(info->cmtd);
mtd_concat_destroy(info->cmtd);
}
if (info->cmtd)
mtd_device_unregister(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("mtd_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);
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 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;
struct mtd_part_parser_data ppdata;
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);
}
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->owner = THIS_MODULE;
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;
ppdata.of_node = dp;
part_probe_types = of_get_probes(dp);
mtd_device_parse_register(info->cmtd, part_probe_types, &ppdata,
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 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",
},
{
.type = "rom",
.compatible = "direct-mapped"
},
{ },
};
MODULE_DEVICE_TABLE(of, of_flash_match);
static struct platform_driver of_flash_driver = {
.driver = {
.name = "of-flash",
.owner = THIS_MODULE,
.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");