[POWERPC] Document and implement an improved flash device binding for powerpc

This replaces the binding for flash chips in booting-without-of.txt
with an clarified and improved version.  It also makes
drivers/mtd/maps/physmap_of.c recognize this new binding.  Finally it
revises the Ebony device tree source to use the new binding as an
example.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
David Gibson
2007-09-07 13:23:53 +10:00
committed by Paul Mackerras
parent 3c607ce2a3
commit 2099172d61
3 changed files with 248 additions and 107 deletions

View File

@@ -4,6 +4,9 @@
* 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
@@ -30,56 +33,135 @@ struct physmap_flash_info {
struct map_info map;
struct resource *res;
#ifdef CONFIG_MTD_PARTITIONS
int nr_parts;
struct mtd_partition *parts;
#endif
};
static const char *rom_probe_types[] = { "cfi_probe", "jedec_probe", "map_rom", NULL };
#ifdef CONFIG_MTD_PARTITIONS
static const char *part_probe_types[] = { "cmdlinepart", "RedBoot", NULL };
#endif
#ifdef CONFIG_MTD_PARTITIONS
static int parse_flash_partitions(struct device_node *node,
struct mtd_partition **parts)
static int parse_obsolete_partitions(struct of_device *dev,
struct physmap_flash_info *info,
struct device_node *dp)
{
int i, plen, retval = -ENOMEM;
const u32 *part;
const char *name;
int i, plen, nr_parts;
const struct {
u32 offset, len;
} *part;
const char *names;
part = of_get_property(node, "partitions", &plen);
if (part == NULL)
goto err;
part = of_get_property(dp, "partitions", &plen);
if (!part)
return -ENOENT;
retval = plen / (2 * sizeof(u32));
*parts = kzalloc(retval * sizeof(struct mtd_partition), GFP_KERNEL);
if (*parts == NULL) {
dev_warn(&dev->dev, "Device tree uses obsolete partition map binding\n");
nr_parts = plen / sizeof(part[0]);
info->parts = kzalloc(nr_parts * sizeof(struct mtd_partition), GFP_KERNEL);
if (!info->parts) {
printk(KERN_ERR "Can't allocate the flash partition data!\n");
goto err;
return -ENOMEM;
}
name = of_get_property(node, "partition-names", &plen);
names = of_get_property(dp, "partition-names", &plen);
for (i = 0; i < retval; i++) {
(*parts)[i].offset = *part++;
(*parts)[i].size = *part & ~1;
if (*part++ & 1) /* bit 0 set signifies read only partition */
(*parts)[i].mask_flags = MTD_WRITEABLE;
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 (name != NULL && plen > 0) {
int len = strlen(name) + 1;
if (names && (plen > 0)) {
int len = strlen(names) + 1;
(*parts)[i].name = (char *)name;
info->parts[i].name = (char *)names;
plen -= len;
name += len;
} else
(*parts)[i].name = "unnamed";
names += len;
} else {
info->parts[i].name = "unnamed";
}
part++;
}
err:
return retval;
return nr_parts;
}
#endif
static int __devinit process_partitions(struct physmap_flash_info *info,
struct of_device *dev)
{
const char *partname;
static const char *part_probe_types[]
= { "cmdlinepart", "RedBoot", NULL };
struct device_node *dp = dev->node, *pp;
int nr_parts, i;
/* First look for RedBoot table or partitions on the command
* line, these take precedence over device tree information */
nr_parts = parse_mtd_partitions(info->mtd, part_probe_types,
&info->parts, 0);
if (nr_parts > 0) {
add_mtd_partitions(info->mtd, info->parts, nr_parts);
return 0;
}
/* First count the subnodes */
nr_parts = 0;
for (pp = dp->child; pp; pp = pp->sibling)
nr_parts++;
if (nr_parts) {
info->parts = kzalloc(nr_parts * sizeof(struct mtd_partition),
GFP_KERNEL);
if (!info->parts) {
printk(KERN_ERR "Can't allocate the flash partition data!\n");
return -ENOMEM;
}
for (pp = dp->child, i = 0 ; pp; pp = pp->sibling, i++) {
const u32 *reg;
int len;
reg = of_get_property(pp, "reg", &len);
if (!reg || (len != 2*sizeof(u32))) {
dev_err(&dev->dev, "Invalid 'reg' on %s\n",
dp->full_name);
kfree(info->parts);
info->parts = NULL;
return -EINVAL;
}
info->parts[i].offset = reg[0];
info->parts[i].size = reg[1];
partname = of_get_property(pp, "label", &len);
if (!partname)
partname = of_get_property(pp, "name", &len);
info->parts[i].name = (char *)partname;
if (of_get_property(pp, "read-only", &len))
info->parts[i].mask_flags = MTD_WRITEABLE;
}
} else {
nr_parts = parse_obsolete_partitions(dev, info, dp);
}
if (nr_parts < 0)
return nr_parts;
if (nr_parts > 0)
add_mtd_partitions(info->mtd, info->parts, nr_parts);
else
add_mtd_device(info->mtd);
return 0;
}
#else /* MTD_PARTITIONS */
static int __devinit process_partitions(struct physmap_flash_info *info,
struct device_node *dev)
{
add_mtd_device(info->mtd);
return 0;
}
#endif /* MTD_PARTITIONS */
static int of_physmap_remove(struct of_device *dev)
{
@@ -92,7 +174,7 @@ static int of_physmap_remove(struct of_device *dev)
if (info->mtd != NULL) {
#ifdef CONFIG_MTD_PARTITIONS
if (info->nr_parts) {
if (info->parts) {
del_mtd_partitions(info->mtd);
kfree(info->parts);
} else {
@@ -115,17 +197,51 @@ static int of_physmap_remove(struct of_device *dev)
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_dbg(&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_physmap_probe(struct of_device *dev, const struct of_device_id *match)
{
struct device_node *dp = dev->node;
struct resource res;
struct physmap_flash_info *info;
const char **probe_type;
const char *of_probe;
const char *probe_type = (const char *)match->data;
const u32 *width;
int err;
if (of_address_to_resource(dp, 0, &res)) {
dev_err(&dev->dev, "Can't get the flash mapping!\n");
err = -EINVAL;
@@ -174,21 +290,11 @@ static int __devinit of_physmap_probe(struct of_device *dev, const struct of_dev
simple_map_init(&info->map);
of_probe = of_get_property(dp, "probe-type", NULL);
if (of_probe == NULL) {
probe_type = rom_probe_types;
for (; info->mtd == NULL && *probe_type != NULL; probe_type++)
info->mtd = do_map_probe(*probe_type, &info->map);
} else if (!strcmp(of_probe, "CFI"))
info->mtd = do_map_probe("cfi_probe", &info->map);
else if (!strcmp(of_probe, "JEDEC"))
info->mtd = do_map_probe("jedec_probe", &info->map);
else {
if (strcmp(of_probe, "ROM"))
dev_dbg(&dev->dev, "map_probe: don't know probe type "
"'%s', mapping as rom\n", of_probe);
info->mtd = do_map_probe("mtd_rom", &info->map);
}
if (probe_type)
info->mtd = do_map_probe(probe_type, &info->map);
else
info->mtd = obsolete_probe(dev, &info->map);
if (info->mtd == NULL) {
dev_err(&dev->dev, "map_probe failed\n");
err = -ENXIO;
@@ -196,19 +302,7 @@ static int __devinit of_physmap_probe(struct of_device *dev, const struct of_dev
}
info->mtd->owner = THIS_MODULE;
#ifdef CONFIG_MTD_PARTITIONS
err = parse_mtd_partitions(info->mtd, part_probe_types, &info->parts, 0);
if (err > 0) {
add_mtd_partitions(info->mtd, info->parts, err);
} else if ((err = parse_flash_partitions(dp, &info->parts)) > 0) {
dev_info(&dev->dev, "Using OF partition information\n");
add_mtd_partitions(info->mtd, info->parts, err);
info->nr_parts = err;
} else
#endif
add_mtd_device(info->mtd);
return 0;
return process_partitions(info, dev);
err_out:
of_physmap_remove(dev);
@@ -220,6 +314,21 @@ err_out:
}
static struct of_device_id of_physmap_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"