path: root/drivers/firewire/core-device.c

/*
 * Device probing and sysfs code.
 *
 * Copyright (C) 2005-2006  Kristian Hoegsberg <krh@bitplanet.net>
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include <linux/bug.h>
#include <linux/ctype.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/firewire.h>
#include <linux/firewire-constants.h>
#include <linux/idr.h>
#include <linux/jiffies.h>
#include <linux/kobject.h>
#include <linux/list.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/rwsem.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/workqueue.h>

#include <linux/atomic.h>
#include <asm/byteorder.h>

#include "core.h"

void fw_csr_iterator_init(struct fw_csr_iterator *ci, const u32 *p)
{
	ci->p = p + 1;
	ci->end = ci->p + (p[0] >> 16);
}
EXPORT_SYMBOL(fw_csr_iterator_init);

int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value)
{
	*key = *ci->p >> 24;
	*value = *ci->p & 0xffffff;

	return ci->p++ < ci->end;
}
EXPORT_SYMBOL(fw_csr_iterator_next);

static const u32 *search_leaf(const u32 *directory, int search_key)
{
	struct fw_csr_iterator ci;
	int last_key = 0, key, value;

	fw_csr_iterator_init(&ci, directory);
	while (fw_csr_iterator_next(&ci, &key, &value)) {
		if (last_key == search_key &&
		    key == (CSR_DESCRIPTOR | CSR_LEAF))
			return ci.p - 1 + value;

		last_key = key;
	}

	return NULL;
}

static int textual_leaf_to_string(const u32 *block, char *buf, size_t size)
{
	unsigned int quadlets, i;
	char c;

	if (!size || !buf)
		return -EINVAL;

	quadlets = min(block[0] >> 16, 256U);
	if (quadlets < 2)
		return -ENODATA;

	if (block[1] != 0 || block[2] != 0)
		/* unknown language/character set */
		return -ENODATA;

	block += 3;
	quadlets -= 2;
	for (i = 0; i < quadlets * 4 && i < size - 1; i++) {
		c = block[i / 4] >> (24 - 8 * (i % 4));
		if (c == '\0')
			break;
		buf[i] = c;
	}
	buf[i] = '\0';

	return i;
}

/**
 * fw_csr_string() - reads a string from the configuration ROM
 * @directory:	e.g. root directory or unit directory
 * @key:	the key of the preceding directory entry
 * @buf:	where to put the string
 * @size:	size of @buf, in bytes
 *
 * The string is taken from a minimal ASCII text descriptor leaf after
 * the immediate entry with @key.  The string is zero-terminated.
 * Returns strlen(buf) or a negative error code.
 */
int fw_csr_string(const u32 *directory, int key, char *buf, size_t size)
{
	const u32 *leaf = search_leaf(directory, key);
	if (!leaf)
		return -ENOENT;

	return textual_leaf_to_string(leaf, buf, size);
}
EXPORT_SYMBOL(fw_csr_string);

static void get_ids(const u32 *directory, int *id)
{
	struct fw_csr_iterator ci;
	int key, value;

	fw_csr_iterator_init(&ci, directory);
	while (fw_csr_iterator_next(&ci, &key, &value)) {
		switch (key) {
		case CSR_VENDOR:	id[0] = value; break;
		case CSR_MODEL:		id[1] = value; break;
		case CSR_SPECIFIER_ID:	id[2] = value; break;
		case CSR_VERSION:	id[3] = value; break;
		}
	}
}

static void get_modalias_ids(struct fw_unit *unit, int *id)
{
	get_ids(&fw_parent_device(unit)->config_rom[5], id);
	get_ids(unit->directory, id);
}

static bool match_ids(const struct ieee1394_device_id *id_table, int *id)
{
	int match = 0;

	if (id[0] == id_table->vendor_id)
		match |= IEEE1394_MATCH_VENDOR_ID;
	if (id[1] == id_table->model_id)
		match |= IEEE1394_MATCH_MODEL_ID;
	if (id[2] == id_table->specifier_id