[deliverable/linux.git] / net / nfc / hci / hcp.c

/*
 * Copyright (C) 2012  Intel Corporation. All rights reserved.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

#define pr_fmt(fmt) "hci: %s: " fmt, __func__

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>

#include <net/nfc/hci.h>

#include "hci.h"

/*
 * Payload is the HCP message data only. Instruction will be prepended.
 * Guarantees that cb will be called upon completion or timeout delay
 * counted from the moment the cmd is sent to the transport.
 */
int nfc_hci_hcp_message_tx(struct nfc_hci_dev *hdev, u8 pipe,
			   u8 type, u8 instruction,
			   const u8 *payload, size_t payload_len,
			   data_exchange_cb_t cb, void *cb_context,
			   unsigned long completion_delay)
{
	struct nfc_dev *ndev = hdev->ndev;
	struct hci_msg *cmd;
	const u8 *ptr = payload;
	int hci_len, err;
	bool firstfrag = true;

	cmd = kzalloc(sizeof(struct hci_msg), GFP_KERNEL);
	if (cmd == NULL)
		return -ENOMEM;

	INIT_LIST_HEAD(&cmd->msg_l);
	skb_queue_head_init(&cmd->msg_frags);
	cmd->wait_response = (type == NFC_HCI_HCP_COMMAND) ? true : false;
	cmd->cb = cb;
	cmd->cb_context = cb_context;
	cmd->completion_delay = completion_delay;

	hci_len = payload_len + 1;
	while (hci_len > 0) {
		struct sk_buff *skb;
		int skb_len, data_link_len;
		struct hcp_packet *packet;

		if (NFC_HCI_HCP_PACKET_HEADER_LEN + hci_len <=
		    hdev->max_data_link_payload)
			data_link_len = hci_len;
		else
			data_link_len = hdev->max_data_link_payload -
					NFC_HCI_HCP_PACKET_HEADER_LEN;

		skb_len = ndev->tx_headroom + NFC_HCI_HCP_PACKET_HEADER_LEN +
			  data_link_len + ndev->tx_tailroom;
		hci_len -= data_link_len;

		skb = alloc_skb(skb_len, GFP_KERNEL);
		if (skb == NULL) {
			err = -ENOMEM;
			goto out_skb_err;
		}
		skb_reserve(skb, ndev->tx_headroom);

		skb_put(skb, NFC_HCI_HCP_PACKET_HEADER_LEN + data_link_len);

		/* Only the last fragment will have the cb bit set to 1 */
		packet = (struct hcp_packet *)skb->data;
		packet->header = pipe;
		if (firstfrag) {
			firstfrag = false;
			packet->message.header = HCP_HEADER(type, instruction);
			if (ptr) {
				memcpy(packet->message.data, ptr,
				       data_link_len - 1);
				ptr += data_link_len - 1;
			}
		} else {
			memcpy(&packet->message, ptr, data_link_len);
			ptr += data_link_len;
		}

		/* This is the last fragment, set the cb bit */
		if (hci_len == 0)
			packet->header |= ~NFC_HCI_FRAGMENT;

		skb_queue_tail(&cmd->msg_frags, skb);
	}

	mutex_lock(&hdev->msg_tx_mutex);

	if (hdev->shutting_down) {
		err = -ESHUTDOWN;
		mutex_unlock(&hdev->msg_tx_mutex);
		goto out_skb_err;
	}

	list_add_tail(&cmd->msg_l, &hdev->msg_tx_queue);
	mutex_unlock(&hdev->msg_tx_mutex);

	schedule_work(&hdev->msg_tx_work);

	return 0;

out_skb_err:
	skb_queue_purge(&cmd->msg_frags);
	kfree(cmd);

	return err;
}

/*
 * Receive hcp message for pipe, with type and cmd.
 * skb contains optional message data only.
 */
void nfc_hci_hcp_message_rx(struct nfc_hci_dev *hdev, u8 pipe, u8 type,
			    u8 instruction, struct sk_buff *skb)
{
	switch (type) {
	case NFC_HCI_HCP_RESPONSE:
		nfc_hci_resp_received(hdev, instruction, skb);
		break;
	case NFC_HCI_HCP_COMMAND:
		nfc_hci_cmd_received(hdev, pipe, instruction, skb);
		break;
	case NFC_HCI_HCP_EVENT:
		nfc_hci_event_received(hdev, pipe, instruction, skb);
		break;
	default:
		pr_err("UNKNOWN MSG Type %d, instruction=%d\n",
		       type, instruction);
		kfree_skb(skb);
		break;
	}
}
Commit	Line	Data
8b8d2e08 EL	1	/*
	2	* Copyright (C) 2012 Intel Corporation. All rights reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
98b32dec	15	* along with this program; if not, see <http://www.gnu.org/licenses/>.
8b8d2e08 EL	16	*/
	17
	18	#define pr_fmt(fmt) "hci: %s: " fmt, __func__
	19
	20	#include <linux/init.h>
	21	#include <linux/kernel.h>
	22	#include <linux/module.h>
	23
	24	#include <net/nfc/hci.h>
	25
	26	#include "hci.h"
	27
	28	/*
	29	* Payload is the HCP message data only. Instruction will be prepended.
	30	* Guarantees that cb will be called upon completion or timeout delay
	31	* counted from the moment the cmd is sent to the transport.
	32	*/
	33	int nfc_hci_hcp_message_tx(struct nfc_hci_dev *hdev, u8 pipe,
	34	u8 type, u8 instruction,
	35	const u8 *payload, size_t payload_len,
b5faa648	36	data_exchange_cb_t cb, void *cb_context,
8b8d2e08 EL	37	unsigned long completion_delay)
	38	{
	39	struct nfc_dev *ndev = hdev->ndev;
	40	struct hci_msg *cmd;
	41	const u8 *ptr = payload;
	42	int hci_len, err;
	43	bool firstfrag = true;
	44
	45	cmd = kzalloc(sizeof(struct hci_msg), GFP_KERNEL);
	46	if (cmd == NULL)
	47	return -ENOMEM;
	48
	49	INIT_LIST_HEAD(&cmd->msg_l);
	50	skb_queue_head_init(&cmd->msg_frags);
	51	cmd->wait_response = (type == NFC_HCI_HCP_COMMAND) ? true : false;
	52	cmd->cb = cb;
b5faa648	53	cmd->cb_context = cb_context;
8b8d2e08 EL	54	cmd->completion_delay = completion_delay;
	55
	56	hci_len = payload_len + 1;
	57	while (hci_len > 0) {
	58	struct sk_buff *skb;
	59	int skb_len, data_link_len;
	60	struct hcp_packet *packet;
	61
	62	if (NFC_HCI_HCP_PACKET_HEADER_LEN + hci_len <=
	63	hdev->max_data_link_payload)
	64	data_link_len = hci_len;
	65	else
	66	data_link_len = hdev->max_data_link_payload -
	67	NFC_HCI_HCP_PACKET_HEADER_LEN;
	68
	69	skb_len = ndev->tx_headroom + NFC_HCI_HCP_PACKET_HEADER_LEN +
	70	data_link_len + ndev->tx_tailroom;
	71	hci_len -= data_link_len;
	72
	73	skb = alloc_skb(skb_len, GFP_KERNEL);
	74	if (skb == NULL) {
	75	err = -ENOMEM;
	76	goto out_skb_err;
	77	}
	78	skb_reserve(skb, ndev->tx_headroom);
	79
	80	skb_put(skb, NFC_HCI_HCP_PACKET_HEADER_LEN + data_link_len);
	81
	82	/* Only the last fragment will have the cb bit set to 1 */
	83	packet = (struct hcp_packet *)skb->data;
	84	packet->header = pipe;
	85	if (firstfrag) {
	86	firstfrag = false;
	87	packet->message.header = HCP_HEADER(type, instruction);
	88	if (ptr) {
	89	memcpy(packet->message.data, ptr,
	90	data_link_len - 1);
	91	ptr += data_link_len - 1;
	92	}
	93	} else {
	94	memcpy(&packet->message, ptr, data_link_len);
	95	ptr += data_link_len;
	96	}
	97
	98	/* This is the last fragment, set the cb bit */
	99	if (hci_len == 0)
	100	packet->header \|= ~NFC_HCI_FRAGMENT;
	101
	102	skb_queue_tail(&cmd->msg_frags, skb);
	103	}
	104
	105	mutex_lock(&hdev->msg_tx_mutex);
f0c91038 EL	106
	107	if (hdev->shutting_down) {
	108	err = -ESHUTDOWN;
	109	mutex_unlock(&hdev->msg_tx_mutex);
	110	goto out_skb_err;
	111	}
	112
f8bf65bf	113	list_add_tail(&cmd->msg_l, &hdev->msg_tx_queue);
8b8d2e08 EL	114	mutex_unlock(&hdev->msg_tx_mutex);
8b8d2e08 EL	115
916082b0	116	schedule_work(&hdev->msg_tx_work);
8b8d2e08 EL	117
	118	return 0;
	119
	120	out_skb_err:
	121	skb_queue_purge(&cmd->msg_frags);
	122	kfree(cmd);
	123
	124	return err;
	125	}
	126
8b8d2e08 EL	127	/*
	128	* Receive hcp message for pipe, with type and cmd.
	129	* skb contains optional message data only.
	130	*/
	131	void nfc_hci_hcp_message_rx(struct nfc_hci_dev *hdev, u8 pipe, u8 type,
	132	u8 instruction, struct sk_buff *skb)
	133	{
	134	switch (type) {
	135	case NFC_HCI_HCP_RESPONSE:
	136	nfc_hci_resp_received(hdev, instruction, skb);
	137	break;
	138	case NFC_HCI_HCP_COMMAND:
	139	nfc_hci_cmd_received(hdev, pipe, instruction, skb);
	140	break;
	141	case NFC_HCI_HCP_EVENT:
	142	nfc_hci_event_received(hdev, pipe, instruction, skb);
	143	break;
	144	default:
	145	pr_err("UNKNOWN MSG Type %d, instruction=%d\n",
	146	type, instruction);
	147	kfree_skb(skb);
	148	break;
	149	}
	150	}