linux_kernel/net/nfc/hci/llc.c

/*
 * Link Layer Control manager
 *
 * Copyright (C) 2012  Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

#include <net/nfc/llc.h>

#include "llc.h"

static struct list_head llc_engines;

int nfc_llc_init(void)
{
	int r;

	INIT_LIST_HEAD(&llc_engines);

	r = nfc_llc_nop_register();
	if (r)
		goto exit;

	r = nfc_llc_shdlc_register();
	if (r)
		goto exit;

	return 0;

exit:
	nfc_llc_exit();
	return r;
}

void nfc_llc_exit(void)
{
	struct nfc_llc_engine *llc_engine, *n;

	list_for_each_entry_safe(llc_engine, n, &llc_engines, entry) {
		list_del(&llc_engine->entry);
		kfree(llc_engine->name);
		kfree(llc_engine);
	}
}

int nfc_llc_register(const char *name, struct nfc_llc_ops *ops)
{
	struct nfc_llc_engine *llc_engine;

	llc_engine = kzalloc(sizeof(struct nfc_llc_engine), GFP_KERNEL);
	if (llc_engine == NULL)
		return -ENOMEM;

	llc_engine->name = kstrdup(name, GFP_KERNEL);
	if (llc_engine->name == NULL) {
		kfree(llc_engine);
		return -ENOMEM;
	}
	llc_engine->ops = ops;

	INIT_LIST_HEAD(&llc_engine->entry);
	list_add_tail(&llc_engine->entry, &llc_engines);

	return 0;
}

static struct nfc_llc_engine *nfc_llc_name_to_engine(const char *name)
{
	struct nfc_llc_engine *llc_engine;

	list_for_each_entry(llc_engine, &llc_engines, entry) {
		if (strcmp(llc_engine->name, name) == 0)
			return llc_engine;
	}

	return NULL;
}

void nfc_llc_unregister(const char *name)
{
	struct nfc_llc_engine *llc_engine;

	llc_engine = nfc_llc_name_to_engine(name);
	if (llc_engine == NULL)
		return;

	list_del(&llc_engine->entry);
	kfree(llc_engine->name);
	kfree(llc_engine);
}

struct nfc_llc *nfc_llc_allocate(const char *name, struct nfc_hci_dev *hdev,
				 xmit_to_drv_t xmit_to_drv,
				 rcv_to_hci_t rcv_to_hci, int tx_headroom,
				 int tx_tailroom, llc_failure_t llc_failure)
{
	struct nfc_llc_engine *llc_engine;
	struct nfc_llc *llc;

	llc_engine = nfc_llc_name_to_engine(name);
	if (llc_engine == NULL)
		return NULL;

	llc = kzalloc(sizeof(struct nfc_llc), GFP_KERNEL);
	if (llc == NULL)
		return NULL;

	llc->data = llc_engine->ops->init(hdev, xmit_to_drv, rcv_to_hci,
					  tx_headroom, tx_tailroom,
					  &llc->rx_headroom, &llc->rx_tailroom,
					  llc_failure);
	if (llc->data == NULL) {
		kfree(llc);
		return NULL;
	}
	llc->ops = llc_engine->ops;

	return llc;
}

void nfc_llc_free(struct nfc_llc *llc)
{
	llc->ops->deinit(llc);
	kfree(llc);
}

inline void nfc_llc_get_rx_head_tail_room(struct nfc_llc *llc, int *rx_headroom,
					  int *rx_tailroom)
{
	*rx_headroom = llc->rx_headroom;
	*rx_tailroom = llc->rx_tailroom;
}

inline int nfc_llc_start(struct nfc_llc *llc)
{
	return llc->ops->start(llc);
}

inline int nfc_llc_stop(struct nfc_llc *llc)
{
	return llc->ops->stop(llc);
}

inline void nfc_llc_rcv_from_drv(struct nfc_llc *llc, struct sk_buff *skb)
{
	llc->ops->rcv_from_drv(llc, skb);
}

inline int nfc_llc_xmit_from_hci(struct nfc_llc *llc, struct sk_buff *skb)
{
	return llc->ops->xmit_from_hci(llc, skb);
}

inline void *nfc_llc_get_data(struct nfc_llc *llc)
{
	return llc->data;
}