/*
* 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, info->mtd,
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");
