NFC: Changed HCI and PN544 HCI driver to use the new HCI LLC Core

The previous shdlc HCI driver and its header are removed from the tree.
PN544 now registers directly with HCI and passes the name of the llc it
requires (shdlc).
HCI instantiation now allocates the required llc instance. The llc is
started when the HCI device is brought up.

Signed-off-by: Eric Lapuyade <[e-mail]>
Signed-off-by: Samuel Ortiz <[e-mail]>

drivers/nfc/Kconfig

···
 
 config PN544_HCI_NFC
 	tristate "HCI PN544 NFC driver"
-	depends on I2C && NFC_SHDLC
+	depends on I2C && NFC_HCI && NFC_SHDLC
 	select CRC_CCITT
 	default n
 	---help---

drivers/nfc/pn544_hci.c

···
 
 #include <linux/nfc.h>
 #include <net/nfc/hci.h>
-#include <net/nfc/shdlc.h>
+#include <net/nfc/llc.h>
 
 #include <linux/nfc/pn544.h>
 
···
 
 struct pn544_hci_info {
 	struct i2c_client *i2c_dev;
-	struct nfc_shdlc *shdlc;
+	struct nfc_hci_dev *hdev;
 
 	enum pn544_state state;
 
···
 	if (r == -EREMOTEIO) {
 		info->hard_fault = r;
 
-		nfc_shdlc_recv_frame(info->shdlc, NULL);
+		nfc_hci_recv_frame(info->hdev, NULL);
 
 		return IRQ_HANDLED;
 	} else if ((r == -ENOMEM) || (r == -EBADMSG)) {
 		return IRQ_HANDLED;
 	}
 
-	nfc_shdlc_recv_frame(info->shdlc, skb);
+	nfc_hci_recv_frame(info->hdev, skb);
 
 	return IRQ_HANDLED;
 }
 
-static int pn544_hci_open(struct nfc_shdlc *shdlc)
+static int pn544_hci_open(struct nfc_hci_dev *hdev)
 {
-	struct pn544_hci_info *info = nfc_shdlc_get_clientdata(shdlc);
+	struct pn544_hci_info *info = nfc_hci_get_clientdata(hdev);
 	int r = 0;
 
 	mutex_lock(&info->info_lock);
···
 	return r;
 }
 
-static void pn544_hci_close(struct nfc_shdlc *shdlc)
+static void pn544_hci_close(struct nfc_hci_dev *hdev)
 {
-	struct pn544_hci_info *info = nfc_shdlc_get_clientdata(shdlc);
+	struct pn544_hci_info *info = nfc_hci_get_clientdata(hdev);
 
 	mutex_lock(&info->info_lock);
 
···
 	mutex_unlock(&info->info_lock);
 }
 
-static int pn544_hci_ready(struct nfc_shdlc *shdlc)
+static int pn544_hci_ready(struct nfc_hci_dev *hdev)
 {
-	struct nfc_hci_dev *hdev = nfc_shdlc_get_hci_dev(shdlc);
 	struct sk_buff *skb;
 	static struct hw_config {
 		u8 adr[2];
···
 	skb_trim(skb, PN544_FRAME_TAILROOM);
 }
 
-static int pn544_hci_xmit(struct nfc_shdlc *shdlc, struct sk_buff *skb)
+static int pn544_hci_xmit(struct nfc_hci_dev *hdev, struct sk_buff *skb)
 {
-	struct pn544_hci_info *info = nfc_shdlc_get_clientdata(shdlc);
+	struct pn544_hci_info *info = nfc_hci_get_clientdata(hdev);
 	struct i2c_client *client = info->i2c_dev;
 	int r;
 
···
 	return r;
 }
 
-static int pn544_hci_start_poll(struct nfc_shdlc *shdlc,
+static int pn544_hci_start_poll(struct nfc_hci_dev *hdev,
 				u32 im_protocols, u32 tm_protocols)
 {
-	struct nfc_hci_dev *hdev = nfc_shdlc_get_hci_dev(shdlc);
 	u8 phases = 0;
 	int r;
 	u8 duration[2];
···
 	return r;
 }
 
-static int pn544_hci_target_from_gate(struct nfc_shdlc *shdlc, u8 gate,
+static int pn544_hci_target_from_gate(struct nfc_hci_dev *hdev, u8 gate,
 				      struct nfc_target *target)
 {
 	switch (gate) {
···
 	return 0;
 }
 
-static int pn544_hci_complete_target_discovered(struct nfc_shdlc *shdlc,
+static int pn544_hci_complete_target_discovered(struct nfc_hci_dev *hdev,
 						u8 gate,
 						struct nfc_target *target)
 {
-	struct nfc_hci_dev *hdev = nfc_shdlc_get_hci_dev(shdlc);
 	struct sk_buff *uid_skb;
 	int r = 0;
 
···
  * <= 0: driver handled the data exchange
  *    1: driver doesn't especially handle, please do standard processing
  */
-static int pn544_hci_data_exchange(struct nfc_shdlc *shdlc,
+static int pn544_hci_data_exchange(struct nfc_hci_dev *hdev,
 				   struct nfc_target *target,
 				   struct sk_buff *skb, data_exchange_cb_t cb,
 				   void *cb_context)
 {
-	struct pn544_hci_info *info = nfc_shdlc_get_clientdata(shdlc);
-	struct nfc_hci_dev *hdev = nfc_shdlc_get_hci_dev(shdlc);
+	struct pn544_hci_info *info = nfc_hci_get_clientdata(hdev);
 
 	pr_info(DRIVER_DESC ": %s for gate=%d\n", __func__,
 		target->hci_reader_gate);
···
 	}
 }
 
-static int pn544_hci_check_presence(struct nfc_shdlc *shdlc,
+static int pn544_hci_check_presence(struct nfc_hci_dev *hdev,
 				   struct nfc_target *target)
 {
-	struct nfc_hci_dev *hdev = nfc_shdlc_get_hci_dev(shdlc);
-
 	return nfc_hci_send_cmd(hdev, target->hci_reader_gate,
 				PN544_RF_READER_CMD_PRESENCE_CHECK,
 				NULL, 0, NULL);
 }
 
-static struct nfc_shdlc_ops pn544_shdlc_ops = {
+static struct nfc_hci_ops pn544_hci_ops = {
 	.open = pn544_hci_open,
 	.close = pn544_hci_close,
 	.hci_ready = pn544_hci_ready,
···
 		    NFC_PROTO_ISO14443_B_MASK |
 		    NFC_PROTO_NFC_DEP_MASK;
 
-	info->shdlc = nfc_shdlc_allocate(&pn544_shdlc_ops,
-					 &init_data, protocols,
-					 PN544_FRAME_HEADROOM + PN544_CMDS_HEADROOM,
-					 PN544_FRAME_TAILROOM,
-					 PN544_HCI_LLC_MAX_PAYLOAD,
-					 dev_name(&client->dev));
-	if (!info->shdlc) {
-		dev_err(&client->dev, "Cannot allocate nfc shdlc.\n");
+	info->hdev = nfc_hci_allocate_device(&pn544_hci_ops, &init_data,
+					     protocols, LLC_SHDLC_NAME,
+					     PN544_FRAME_HEADROOM +
+					     PN544_CMDS_HEADROOM,
+					     PN544_FRAME_TAILROOM,
+					     PN544_HCI_LLC_MAX_PAYLOAD);
+	if (!info->hdev) {
+		dev_err(&client->dev, "Cannot allocate nfc hdev.\n");
 		r = -ENOMEM;
-		goto err_allocshdlc;
+		goto err_alloc_hdev;
 	}
 
-	nfc_shdlc_set_clientdata(info->shdlc, info);
+	nfc_hci_set_clientdata(info->hdev, info);
+
+	r = nfc_hci_register_device(info->hdev);
+	if (r)
+		goto err_regdev;
 
 	return 0;
 
-err_allocshdlc:
+err_regdev:
+	nfc_hci_free_device(info->hdev);
+
+err_alloc_hdev:
 	free_irq(client->irq, info);
 
 err_rti:
···
 
 	dev_dbg(&client->dev, "%s\n", __func__);
 
-	nfc_shdlc_free(info->shdlc);
+	nfc_hci_free_device(info->hdev);
 
 	if (info->state != PN544_ST_COLD) {
 		if (pdata->disable)

include/net/nfc/hci.h

···
 
 	struct nfc_hci_ops *ops;
 
+	struct nfc_llc *llc;
+
 	struct nfc_hci_init_data init_data;
 
 	void *clientdata;
···
 struct nfc_hci_dev *nfc_hci_allocate_device(struct nfc_hci_ops *ops,
 					    struct nfc_hci_init_data *init_data,
 					    u32 protocols,
+					    const char *llc_name,
 					    int tx_headroom,
 					    int tx_tailroom,
 					    int max_link_payload);

include/net/nfc/shdlc.h

···
-/*
- * 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, write to the
- * Free Software Foundation, Inc.,
- * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- */
-
-#ifndef __NFC_SHDLC_H
-#define __NFC_SHDLC_H
-
-struct nfc_shdlc;
-
-struct nfc_shdlc_ops {
-	int (*open) (struct nfc_shdlc *shdlc);
-	void (*close) (struct nfc_shdlc *shdlc);
-	int (*hci_ready) (struct nfc_shdlc *shdlc);
-	int (*xmit) (struct nfc_shdlc *shdlc, struct sk_buff *skb);
-	int (*start_poll) (struct nfc_shdlc *shdlc,
-			   u32 im_protocols, u32 tm_protocols);
-	int (*target_from_gate) (struct nfc_shdlc *shdlc, u8 gate,
-				 struct nfc_target *target);
-	int (*complete_target_discovered) (struct nfc_shdlc *shdlc, u8 gate,
-					   struct nfc_target *target);
-	int (*data_exchange) (struct nfc_shdlc *shdlc,
-			      struct nfc_target *target, struct sk_buff *skb,
-			      data_exchange_cb_t cb, void *cb_context);
-	int (*check_presence)(struct nfc_shdlc *shdlc,
-			      struct nfc_target *target);
-};
-
-enum shdlc_state {
-	SHDLC_DISCONNECTED = 0,
-	SHDLC_CONNECTING = 1,
-	SHDLC_NEGOCIATING = 2,
-	SHDLC_CONNECTED = 3
-};
-
-struct nfc_shdlc {
-	struct mutex state_mutex;
-	enum shdlc_state state;
-	int hard_fault;
-
-	struct nfc_hci_dev *hdev;
-
-	wait_queue_head_t *connect_wq;
-	int connect_tries;
-	int connect_result;
-	struct timer_list connect_timer;/* aka T3 in spec 10.6.1 */
-
-	u8 w;				/* window size */
-	bool srej_support;
-
-	struct timer_list t1_timer;	/* send ack timeout */
-	bool t1_active;
-
-	struct timer_list t2_timer;	/* guard/retransmit timeout */
-	bool t2_active;
-
-	int ns;				/* next seq num for send */
-	int nr;				/* next expected seq num for receive */
-	int dnr;			/* oldest sent unacked seq num */
-
-	struct sk_buff_head rcv_q;
-
-	struct sk_buff_head send_q;
-	bool rnr;			/* other side is not ready to receive */
-
-	struct sk_buff_head ack_pending_q;
-
-	struct work_struct sm_work;
-
-	struct nfc_shdlc_ops *ops;
-
-	int client_headroom;
-	int client_tailroom;
-
-	void *clientdata;
-};
-
-void nfc_shdlc_recv_frame(struct nfc_shdlc *shdlc, struct sk_buff *skb);
-
-struct nfc_shdlc *nfc_shdlc_allocate(struct nfc_shdlc_ops *ops,
-				     struct nfc_hci_init_data *init_data,
-				     u32 protocols,
-				     int tx_headroom, int tx_tailroom,
-				     int max_link_payload, const char *devname);
-
-void nfc_shdlc_free(struct nfc_shdlc *shdlc);
-
-void nfc_shdlc_set_clientdata(struct nfc_shdlc *shdlc, void *clientdata);
-void *nfc_shdlc_get_clientdata(struct nfc_shdlc *shdlc);
-struct nfc_hci_dev *nfc_shdlc_get_hci_dev(struct nfc_shdlc *shdlc);
-
-#endif /* __NFC_SHDLC_H */

net/nfc/hci/Makefile

···
 obj-$(CONFIG_NFC_HCI) += hci.o
 
 hci-y			:= core.o hcp.o command.o llc.o llc_nop.o
-hci-$(CONFIG_NFC_SHDLC) += shdlc.o llc_shdlc.o
+hci-$(CONFIG_NFC_SHDLC) += llc_shdlc.o

net/nfc/hci/core.c

···
 
 	pr_debug("msg_tx_queue has a cmd to send\n");
 	while ((skb = skb_dequeue(&msg->msg_frags)) != NULL) {
-		r = hdev->ops->xmit(hdev, skb);
+		r = nfc_llc_xmit_from_hci(hdev->llc, skb);
 		if (r < 0) {
 			kfree_skb(skb);
 			skb_queue_purge(&msg->msg_frags);
···
 			return r;
 	}
 
+	r = nfc_llc_start(hdev->llc);
+	if (r < 0)
+		goto exit_close;
+
 	r = hci_dev_session_init(hdev);
 	if (r < 0)
-		goto exit;
+		goto exit_llc;
 
 	r = nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,
 			       NFC_HCI_EVT_END_OPERATION, NULL, 0);
 	if (r < 0)
-		goto exit;
+		goto exit_llc;
 
 	if (hdev->ops->hci_ready) {
 		r = hdev->ops->hci_ready(hdev);
 		if (r < 0)
-			goto exit;
+			goto exit_llc;
 	}
 
 	r = hci_dev_version(hdev);
 	if (r < 0)
-		goto exit;
+		goto exit_llc;
 
-exit:
-	if (r < 0)
-		if (hdev->ops->close)
-			hdev->ops->close(hdev);
+	return 0;
+
+exit_llc:
+	nfc_llc_stop(hdev->llc);
+
+exit_close:
+	if (hdev->ops->close)
+		hdev->ops->close(hdev);
+
 	return r;
 }
 
 static int hci_dev_down(struct nfc_dev *nfc_dev)
 {
 	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
+
+	nfc_llc_stop(hdev->llc);
 
 	if (hdev->ops->close)
 		hdev->ops->close(hdev);
···
 	return 0;
 }
 
-static struct nfc_ops hci_nfc_ops = {
-	.dev_up = hci_dev_up,
-	.dev_down = hci_dev_down,
-	.start_poll = hci_start_poll,
-	.stop_poll = hci_stop_poll,
-	.activate_target = hci_activate_target,
-	.deactivate_target = hci_deactivate_target,
-	.im_transceive = hci_transceive,
-	.check_presence = hci_check_presence,
-};
-
-struct nfc_hci_dev *nfc_hci_allocate_device(struct nfc_hci_ops *ops,
-					    struct nfc_hci_init_data *init_data,
-					    u32 protocols,
-					    int tx_headroom,
-					    int tx_tailroom,
-					    int max_link_payload)
-{
-	struct nfc_hci_dev *hdev;
-
-	if (ops->xmit == NULL)
-		return NULL;
-
-	if (protocols == 0)
-		return NULL;
-
-	hdev = kzalloc(sizeof(struct nfc_hci_dev), GFP_KERNEL);
-	if (hdev == NULL)
-		return NULL;
-
-	hdev->ndev = nfc_allocate_device(&hci_nfc_ops, protocols,
-					 tx_headroom + HCI_CMDS_HEADROOM,
-					 tx_tailroom);
-	if (!hdev->ndev) {
-		kfree(hdev);
-		return NULL;
-	}
-
-	hdev->ops = ops;
-	hdev->max_data_link_payload = max_link_payload;
-	hdev->init_data = *init_data;
-
-	nfc_set_drvdata(hdev->ndev, hdev);
-
-	memset(hdev->gate2pipe, NFC_HCI_INVALID_PIPE, sizeof(hdev->gate2pipe));
-
-	return hdev;
-}
-EXPORT_SYMBOL(nfc_hci_allocate_device);
-
-void nfc_hci_free_device(struct nfc_hci_dev *hdev)
-{
-	nfc_free_device(hdev->ndev);
-	kfree(hdev);
-}
-EXPORT_SYMBOL(nfc_hci_free_device);
-
-int nfc_hci_register_device(struct nfc_hci_dev *hdev)
-{
-	mutex_init(&hdev->msg_tx_mutex);
-
-	INIT_LIST_HEAD(&hdev->msg_tx_queue);
-
-	INIT_WORK(&hdev->msg_tx_work, nfc_hci_msg_tx_work);
-
-	init_timer(&hdev->cmd_timer);
-	hdev->cmd_timer.data = (unsigned long)hdev;
-	hdev->cmd_timer.function = nfc_hci_cmd_timeout;
-
-	skb_queue_head_init(&hdev->rx_hcp_frags);
-
-	INIT_WORK(&hdev->msg_rx_work, nfc_hci_msg_rx_work);
-
-	skb_queue_head_init(&hdev->msg_rx_queue);
-
-	return nfc_register_device(hdev->ndev);
-}
-EXPORT_SYMBOL(nfc_hci_register_device);
-
-void nfc_hci_unregister_device(struct nfc_hci_dev *hdev)
-{
-	struct hci_msg *msg, *n;
-
-	skb_queue_purge(&hdev->rx_hcp_frags);
-	skb_queue_purge(&hdev->msg_rx_queue);
-
-	list_for_each_entry_safe(msg, n, &hdev->msg_tx_queue, msg_l) {
-		list_del(&msg->msg_l);
-		skb_queue_purge(&msg->msg_frags);
-		kfree(msg);
-	}
-
-	del_timer_sync(&hdev->cmd_timer);
-
-	nfc_unregister_device(hdev->ndev);
-
-	cancel_work_sync(&hdev->msg_tx_work);
-	cancel_work_sync(&hdev->msg_rx_work);
-}
-EXPORT_SYMBOL(nfc_hci_unregister_device);
-
-void nfc_hci_set_clientdata(struct nfc_hci_dev *hdev, void *clientdata)
-{
-	hdev->clientdata = clientdata;
-}
-EXPORT_SYMBOL(nfc_hci_set_clientdata);
-
-void *nfc_hci_get_clientdata(struct nfc_hci_dev *hdev)
-{
-	return hdev->clientdata;
-}
-EXPORT_SYMBOL(nfc_hci_get_clientdata);
-
 static void nfc_hci_failure(struct nfc_hci_dev *hdev, int err)
 {
 	mutex_lock(&hdev->msg_tx_mutex);
···
 	mutex_unlock(&hdev->msg_tx_mutex);
 }
 
-void nfc_hci_driver_failure(struct nfc_hci_dev *hdev, int err)
+static void nfc_hci_llc_failure(struct nfc_hci_dev *hdev, int err)
 {
 	nfc_hci_failure(hdev, err);
 }
-EXPORT_SYMBOL(nfc_hci_driver_failure);
 
-void nfc_hci_recv_frame(struct nfc_hci_dev *hdev, struct sk_buff *skb)
+static void nfc_hci_recv_from_llc(struct nfc_hci_dev *hdev, struct sk_buff *skb)
 {
 	struct hcp_packet *packet;
 	u8 type;
···
 		queue_work(system_nrt_wq, &hdev->msg_rx_work);
 	}
 }
+
+static struct nfc_ops hci_nfc_ops = {
+	.dev_up = hci_dev_up,
+	.dev_down = hci_dev_down,
+	.start_poll = hci_start_poll,
+	.stop_poll = hci_stop_poll,
+	.activate_target = hci_activate_target,
+	.deactivate_target = hci_deactivate_target,
+	.im_transceive = hci_transceive,
+	.check_presence = hci_check_presence,
+};
+
+struct nfc_hci_dev *nfc_hci_allocate_device(struct nfc_hci_ops *ops,
+					    struct nfc_hci_init_data *init_data,
+					    u32 protocols,
+					    const char *llc_name,
+					    int tx_headroom,
+					    int tx_tailroom,
+					    int max_link_payload)
+{
+	struct nfc_hci_dev *hdev;
+
+	if (ops->xmit == NULL)
+		return NULL;
+
+	if (protocols == 0)
+		return NULL;
+
+	hdev = kzalloc(sizeof(struct nfc_hci_dev), GFP_KERNEL);
+	if (hdev == NULL)
+		return NULL;
+
+	hdev->llc = nfc_llc_allocate(llc_name, hdev, ops->xmit,
+				     nfc_hci_recv_from_llc, tx_headroom,
+				     tx_tailroom, nfc_hci_llc_failure);
+	if (hdev->llc == NULL) {
+		kfree(hdev);
+		return NULL;
+	}
+
+	hdev->ndev = nfc_allocate_device(&hci_nfc_ops, protocols,
+					 tx_headroom + HCI_CMDS_HEADROOM,
+					 tx_tailroom);
+	if (!hdev->ndev) {
+		nfc_llc_free(hdev->llc);
+		kfree(hdev);
+		return NULL;
+	}
+
+	hdev->ops = ops;
+	hdev->max_data_link_payload = max_link_payload;
+	hdev->init_data = *init_data;
+
+	nfc_set_drvdata(hdev->ndev, hdev);
+
+	memset(hdev->gate2pipe, NFC_HCI_INVALID_PIPE, sizeof(hdev->gate2pipe));
+
+	return hdev;
+}
+EXPORT_SYMBOL(nfc_hci_allocate_device);
+
+void nfc_hci_free_device(struct nfc_hci_dev *hdev)
+{
+	nfc_free_device(hdev->ndev);
+	nfc_llc_free(hdev->llc);
+	kfree(hdev);
+}
+EXPORT_SYMBOL(nfc_hci_free_device);
+
+int nfc_hci_register_device(struct nfc_hci_dev *hdev)
+{
+	mutex_init(&hdev->msg_tx_mutex);
+
+	INIT_LIST_HEAD(&hdev->msg_tx_queue);
+
+	INIT_WORK(&hdev->msg_tx_work, nfc_hci_msg_tx_work);
+
+	init_timer(&hdev->cmd_timer);
+	hdev->cmd_timer.data = (unsigned long)hdev;
+	hdev->cmd_timer.function = nfc_hci_cmd_timeout;
+
+	skb_queue_head_init(&hdev->rx_hcp_frags);
+
+	INIT_WORK(&hdev->msg_rx_work, nfc_hci_msg_rx_work);
+
+	skb_queue_head_init(&hdev->msg_rx_queue);
+
+	return nfc_register_device(hdev->ndev);
+}
+EXPORT_SYMBOL(nfc_hci_register_device);
+
+void nfc_hci_unregister_device(struct nfc_hci_dev *hdev)
+{
+	struct hci_msg *msg, *n;
+
+	skb_queue_purge(&hdev->rx_hcp_frags);
+	skb_queue_purge(&hdev->msg_rx_queue);
+
+	list_for_each_entry_safe(msg, n, &hdev->msg_tx_queue, msg_l) {
+		list_del(&msg->msg_l);
+		skb_queue_purge(&msg->msg_frags);
+		kfree(msg);
+	}
+
+	del_timer_sync(&hdev->cmd_timer);
+
+	nfc_unregister_device(hdev->ndev);
+
+	cancel_work_sync(&hdev->msg_tx_work);
+	cancel_work_sync(&hdev->msg_rx_work);
+}
+EXPORT_SYMBOL(nfc_hci_unregister_device);
+
+void nfc_hci_set_clientdata(struct nfc_hci_dev *hdev, void *clientdata)
+{
+	hdev->clientdata = clientdata;
+}
+EXPORT_SYMBOL(nfc_hci_set_clientdata);
+
+void *nfc_hci_get_clientdata(struct nfc_hci_dev *hdev)
+{
+	return hdev->clientdata;
+}
+EXPORT_SYMBOL(nfc_hci_get_clientdata);
+
+void nfc_hci_driver_failure(struct nfc_hci_dev *hdev, int err)
+{
+	nfc_hci_failure(hdev, err);
+}
+EXPORT_SYMBOL(nfc_hci_driver_failure);
+
+void inline nfc_hci_recv_frame(struct nfc_hci_dev *hdev, struct sk_buff *skb)
+{
+	nfc_llc_rcv_from_drv(hdev->llc, skb);
+}
 EXPORT_SYMBOL(nfc_hci_recv_frame);
 
 static int __init nfc_hci_init(void)
···
 	nfc_llc_exit();
 }
 
-module_init(nfc_hci_init);
+subsys_initcall(nfc_hci_init);
 module_exit(nfc_hci_exit);
 
 MODULE_LICENSE("GPL");

net/nfc/hci/llc_shdlc.c

···
 
 		pr_debug("Sending I-Frame %d, waiting to rcv %d\n", shdlc->ns,
 			 shdlc->nr);
-	/*	SHDLC_DUMP_SKB("shdlc frame written", skb); */
+		SHDLC_DUMP_SKB("shdlc frame written", skb);
 
 		r = shdlc->xmit_to_drv(shdlc->hdev, skb);
 		if (r < 0) {

net/nfc/hci/shdlc.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, write to the
- * Free Software Foundation, Inc.,
- * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- */
-
-#define pr_fmt(fmt) "shdlc: %s: " fmt, __func__
-
-#include <linux/sched.h>
-#include <linux/export.h>
-#include <linux/wait.h>
-#include <linux/slab.h>
-#include <linux/skbuff.h>
-
-#include <net/nfc/hci.h>
-#include <net/nfc/shdlc.h>
-
-#define SHDLC_LLC_HEAD_ROOM	2
-
-#define SHDLC_MAX_WINDOW	4
-#define SHDLC_SREJ_SUPPORT	false
-
-#define SHDLC_CONTROL_HEAD_MASK	0xe0
-#define SHDLC_CONTROL_HEAD_I	0x80
-#define SHDLC_CONTROL_HEAD_I2	0xa0
-#define SHDLC_CONTROL_HEAD_S	0xc0
-#define SHDLC_CONTROL_HEAD_U	0xe0
-
-#define SHDLC_CONTROL_NS_MASK	0x38
-#define SHDLC_CONTROL_NR_MASK	0x07
-#define SHDLC_CONTROL_TYPE_MASK	0x18
-
-#define SHDLC_CONTROL_M_MASK	0x1f
-
-enum sframe_type {
-	S_FRAME_RR = 0x00,
-	S_FRAME_REJ = 0x01,
-	S_FRAME_RNR = 0x02,
-	S_FRAME_SREJ = 0x03
-};
-
-enum uframe_modifier {
-	U_FRAME_UA = 0x06,
-	U_FRAME_RSET = 0x19
-};
-
-#define SHDLC_CONNECT_VALUE_MS	5
-#define SHDLC_T1_VALUE_MS(w)	((5 * w) / 4)
-#define SHDLC_T2_VALUE_MS	300
-
-#define SHDLC_DUMP_SKB(info, skb)				  \
-do {								  \
-	pr_debug("%s:\n", info);				  \
-	print_hex_dump(KERN_DEBUG, "shdlc: ", DUMP_PREFIX_OFFSET, \
-		       16, 1, skb->data, skb->len, 0);		  \
-} while (0)
-
-/* checks x < y <= z modulo 8 */
-static bool nfc_shdlc_x_lt_y_lteq_z(int x, int y, int z)
-{
-	if (x < z)
-		return ((x < y) && (y <= z)) ? true : false;
-	else
-		return ((y > x) || (y <= z)) ? true : false;
-}
-
-/* checks x <= y < z modulo 8 */
-static bool nfc_shdlc_x_lteq_y_lt_z(int x, int y, int z)
-{
-	if (x <= z)
-		return ((x <= y) && (y < z)) ? true : false;
-	else			/* x > z -> z+8 > x */
-		return ((y >= x) || (y < z)) ? true : false;
-}
-
-static struct sk_buff *nfc_shdlc_alloc_skb(struct nfc_shdlc *shdlc,
-					   int payload_len)
-{
-	struct sk_buff *skb;
-
-	skb = alloc_skb(shdlc->client_headroom + SHDLC_LLC_HEAD_ROOM +
-			shdlc->client_tailroom + payload_len, GFP_KERNEL);
-	if (skb)
-		skb_reserve(skb, shdlc->client_headroom + SHDLC_LLC_HEAD_ROOM);
-
-	return skb;
-}
-
-/* immediately sends an S frame. */
-static int nfc_shdlc_send_s_frame(struct nfc_shdlc *shdlc,
-				  enum sframe_type sframe_type, int nr)
-{
-	int r;
-	struct sk_buff *skb;
-
-	pr_debug("sframe_type=%d nr=%d\n", sframe_type, nr);
-
-	skb = nfc_shdlc_alloc_skb(shdlc, 0);
-	if (skb == NULL)
-		return -ENOMEM;
-
-	*skb_push(skb, 1) = SHDLC_CONTROL_HEAD_S | (sframe_type << 3) | nr;
-
-	r = shdlc->ops->xmit(shdlc, skb);
-
-	kfree_skb(skb);
-
-	return r;
-}
-
-/* immediately sends an U frame. skb may contain optional payload */
-static int nfc_shdlc_send_u_frame(struct nfc_shdlc *shdlc,
-				  struct sk_buff *skb,
-				  enum uframe_modifier uframe_modifier)
-{
-	int r;
-
-	pr_debug("uframe_modifier=%d\n", uframe_modifier);
-
-	*skb_push(skb, 1) = SHDLC_CONTROL_HEAD_U | uframe_modifier;
-
-	r = shdlc->ops->xmit(shdlc, skb);
-
-	kfree_skb(skb);
-
-	return r;
-}
-
-/*
- * Free ack_pending frames until y_nr - 1, and reset t2 according to
- * the remaining oldest ack_pending frame sent time
- */
-static void nfc_shdlc_reset_t2(struct nfc_shdlc *shdlc, int y_nr)
-{
-	struct sk_buff *skb;
-	int dnr = shdlc->dnr;	/* MUST initially be < y_nr */
-
-	pr_debug("release ack pending up to frame %d excluded\n", y_nr);
-
-	while (dnr != y_nr) {
-		pr_debug("release ack pending frame %d\n", dnr);
-
-		skb = skb_dequeue(&shdlc->ack_pending_q);
-		kfree_skb(skb);
-
-		dnr = (dnr + 1) % 8;
-	}
-
-	if (skb_queue_empty(&shdlc->ack_pending_q)) {
-		if (shdlc->t2_active) {
-			del_timer_sync(&shdlc->t2_timer);
-			shdlc->t2_active = false;
-
-			pr_debug
-			    ("All sent frames acked. Stopped T2(retransmit)\n");
-		}
-	} else {
-		skb = skb_peek(&shdlc->ack_pending_q);
-
-		mod_timer(&shdlc->t2_timer, *(unsigned long *)skb->cb +
-			  msecs_to_jiffies(SHDLC_T2_VALUE_MS));
-		shdlc->t2_active = true;
-
-		pr_debug
-		    ("Start T2(retransmit) for remaining unacked sent frames\n");
-	}
-}
-
-/*
- * Receive validated frames from lower layer. skb contains HCI payload only.
- * Handle according to algorithm at spec:10.8.2
- */
-static void nfc_shdlc_rcv_i_frame(struct nfc_shdlc *shdlc,
-				  struct sk_buff *skb, int ns, int nr)
-{
-	int x_ns = ns;
-	int y_nr = nr;
-
-	pr_debug("recvd I-frame %d, remote waiting frame %d\n", ns, nr);
-
-	if (shdlc->state != SHDLC_CONNECTED)
-		goto exit;
-
-	if (x_ns != shdlc->nr) {
-		nfc_shdlc_send_s_frame(shdlc, S_FRAME_REJ, shdlc->nr);
-		goto exit;
-	}
-
-	if (shdlc->t1_active == false) {
-		shdlc->t1_active = true;
-		mod_timer(&shdlc->t1_timer,
-			  msecs_to_jiffies(SHDLC_T1_VALUE_MS(shdlc->w)));
-		pr_debug("(re)Start T1(send ack)\n");
-	}
-
-	if (skb->len) {
-		nfc_hci_recv_frame(shdlc->hdev, skb);
-		skb = NULL;
-	}
-
-	shdlc->nr = (shdlc->nr + 1) % 8;
-
-	if (nfc_shdlc_x_lt_y_lteq_z(shdlc->dnr, y_nr, shdlc->ns)) {
-		nfc_shdlc_reset_t2(shdlc, y_nr);
-
-		shdlc->dnr = y_nr;
-	}
-
-exit:
-	kfree_skb(skb);
-}
-
-static void nfc_shdlc_rcv_ack(struct nfc_shdlc *shdlc, int y_nr)
-{
-	pr_debug("remote acked up to frame %d excluded\n", y_nr);
-
-	if (nfc_shdlc_x_lt_y_lteq_z(shdlc->dnr, y_nr, shdlc->ns)) {
-		nfc_shdlc_reset_t2(shdlc, y_nr);
-		shdlc->dnr = y_nr;
-	}
-}
-
-static void nfc_shdlc_requeue_ack_pending(struct nfc_shdlc *shdlc)
-{
-	struct sk_buff *skb;
-
-	pr_debug("ns reset to %d\n", shdlc->dnr);
-
-	while ((skb = skb_dequeue_tail(&shdlc->ack_pending_q))) {
-		skb_pull(skb, 1);  /* remove control field */
-		skb_queue_head(&shdlc->send_q, skb);
-	}
-	shdlc->ns = shdlc->dnr;
-}
-
-static void nfc_shdlc_rcv_rej(struct nfc_shdlc *shdlc, int y_nr)
-{
-	struct sk_buff *skb;
-
-	pr_debug("remote asks retransmition from frame %d\n", y_nr);
-
-	if (nfc_shdlc_x_lteq_y_lt_z(shdlc->dnr, y_nr, shdlc->ns)) {
-		if (shdlc->t2_active) {
-			del_timer_sync(&shdlc->t2_timer);
-			shdlc->t2_active = false;
-			pr_debug("Stopped T2(retransmit)\n");
-		}
-
-		if (shdlc->dnr != y_nr) {
-			while ((shdlc->dnr = ((shdlc->dnr + 1) % 8)) != y_nr) {
-				skb = skb_dequeue(&shdlc->ack_pending_q);
-				kfree_skb(skb);
-			}
-		}
-
-		nfc_shdlc_requeue_ack_pending(shdlc);
-	}
-}
-
-/* See spec RR:10.8.3 REJ:10.8.4 */
-static void nfc_shdlc_rcv_s_frame(struct nfc_shdlc *shdlc,
-				  enum sframe_type s_frame_type, int nr)
-{
-	struct sk_buff *skb;
-
-	if (shdlc->state != SHDLC_CONNECTED)
-		return;
-
-	switch (s_frame_type) {
-	case S_FRAME_RR:
-		nfc_shdlc_rcv_ack(shdlc, nr);
-		if (shdlc->rnr == true) {	/* see SHDLC 10.7.7 */
-			shdlc->rnr = false;
-			if (shdlc->send_q.qlen == 0) {
-				skb = nfc_shdlc_alloc_skb(shdlc, 0);
-				if (skb)
-					skb_queue_tail(&shdlc->send_q, skb);
-			}
-		}
-		break;
-	case S_FRAME_REJ:
-		nfc_shdlc_rcv_rej(shdlc, nr);
-		break;
-	case S_FRAME_RNR:
-		nfc_shdlc_rcv_ack(shdlc, nr);
-		shdlc->rnr = true;
-		break;
-	default:
-		break;
-	}
-}
-
-static void nfc_shdlc_connect_complete(struct nfc_shdlc *shdlc, int r)
-{
-	pr_debug("result=%d\n", r);
-
-	del_timer_sync(&shdlc->connect_timer);
-
-	if (r == 0) {
-		shdlc->ns = 0;
-		shdlc->nr = 0;
-		shdlc->dnr = 0;
-
-		shdlc->state = SHDLC_CONNECTED;
-	} else {
-		shdlc->state = SHDLC_DISCONNECTED;
-	}
-
-	shdlc->connect_result = r;
-
-	wake_up(shdlc->connect_wq);
-}
-
-static int nfc_shdlc_connect_initiate(struct nfc_shdlc *shdlc)
-{
-	struct sk_buff *skb;
-
-	pr_debug("\n");
-
-	skb = nfc_shdlc_alloc_skb(shdlc, 2);
-	if (skb == NULL)
-		return -ENOMEM;
-
-	*skb_put(skb, 1) = SHDLC_MAX_WINDOW;
-	*skb_put(skb, 1) = SHDLC_SREJ_SUPPORT ? 1 : 0;
-
-	return nfc_shdlc_send_u_frame(shdlc, skb, U_FRAME_RSET);
-}
-
-static int nfc_shdlc_connect_send_ua(struct nfc_shdlc *shdlc)
-{
-	struct sk_buff *skb;
-
-	pr_debug("\n");
-
-	skb = nfc_shdlc_alloc_skb(shdlc, 0);
-	if (skb == NULL)
-		return -ENOMEM;
-
-	return nfc_shdlc_send_u_frame(shdlc, skb, U_FRAME_UA);
-}
-
-static void nfc_shdlc_rcv_u_frame(struct nfc_shdlc *shdlc,
-				  struct sk_buff *skb,
-				  enum uframe_modifier u_frame_modifier)
-{
-	u8 w = SHDLC_MAX_WINDOW;
-	bool srej_support = SHDLC_SREJ_SUPPORT;
-	int r;
-
-	pr_debug("u_frame_modifier=%d\n", u_frame_modifier);
-
-	switch (u_frame_modifier) {
-	case U_FRAME_RSET:
-		if (shdlc->state == SHDLC_NEGOCIATING) {
-			/* we sent RSET, but chip wants to negociate */
-			if (skb->len > 0)
-				w = skb->data[0];
-
-			if (skb->len > 1)
-				srej_support = skb->data[1] & 0x01 ? true :
-					       false;
-
-			if ((w <= SHDLC_MAX_WINDOW) &&
-			    (SHDLC_SREJ_SUPPORT || (srej_support == false))) {
-				shdlc->w = w;
-				shdlc->srej_support = srej_support;
-				r = nfc_shdlc_connect_send_ua(shdlc);
-				nfc_shdlc_connect_complete(shdlc, r);
-			}
-		} else if (shdlc->state == SHDLC_CONNECTED) {
-			/*
-			 * Chip wants to reset link. This is unexpected and
-			 * unsupported.
-			 */
-			shdlc->hard_fault = -ECONNRESET;
-		}
-		break;
-	case U_FRAME_UA:
-		if ((shdlc->state == SHDLC_CONNECTING &&
-		     shdlc->connect_tries > 0) ||
-		    (shdlc->state == SHDLC_NEGOCIATING))
-			nfc_shdlc_connect_complete(shdlc, 0);
-		break;
-	default:
-		break;
-	}
-
-	kfree_skb(skb);
-}
-
-static void nfc_shdlc_handle_rcv_queue(struct nfc_shdlc *shdlc)
-{
-	struct sk_buff *skb;
-	u8 control;
-	int nr;
-	int ns;
-	enum sframe_type s_frame_type;
-	enum uframe_modifier u_frame_modifier;
-
-	if (shdlc->rcv_q.qlen)
-		pr_debug("rcvQlen=%d\n", shdlc->rcv_q.qlen);
-
-	while ((skb = skb_dequeue(&shdlc->rcv_q)) != NULL) {
-		control = skb->data[0];
-		skb_pull(skb, 1);
-		switch (control & SHDLC_CONTROL_HEAD_MASK) {
-		case SHDLC_CONTROL_HEAD_I:
-		case SHDLC_CONTROL_HEAD_I2:
-			ns = (control & SHDLC_CONTROL_NS_MASK) >> 3;
-			nr = control & SHDLC_CONTROL_NR_MASK;
-			nfc_shdlc_rcv_i_frame(shdlc, skb, ns, nr);
-			break;
-		case SHDLC_CONTROL_HEAD_S:
-			s_frame_type = (control & SHDLC_CONTROL_TYPE_MASK) >> 3;
-			nr = control & SHDLC_CONTROL_NR_MASK;
-			nfc_shdlc_rcv_s_frame(shdlc, s_frame_type, nr);
-			kfree_skb(skb);
-			break;
-		case SHDLC_CONTROL_HEAD_U:
-			u_frame_modifier = control & SHDLC_CONTROL_M_MASK;
-			nfc_shdlc_rcv_u_frame(shdlc, skb, u_frame_modifier);
-			break;
-		default:
-			pr_err("UNKNOWN Control=%d\n", control);
-			kfree_skb(skb);
-			break;
-		}
-	}
-}
-
-static int nfc_shdlc_w_used(int ns, int dnr)
-{
-	int unack_count;
-
-	if (dnr <= ns)
-		unack_count = ns - dnr;
-	else
-		unack_count = 8 - dnr + ns;
-
-	return unack_count;
-}
-
-/* Send frames according to algorithm at spec:10.8.1 */
-static void nfc_shdlc_handle_send_queue(struct nfc_shdlc *shdlc)
-{
-	struct sk_buff *skb;
-	int r;
-	unsigned long time_sent;
-
-	if (shdlc->send_q.qlen)
-		pr_debug
-		    ("sendQlen=%d ns=%d dnr=%d rnr=%s w_room=%d unackQlen=%d\n",
-		     shdlc->send_q.qlen, shdlc->ns, shdlc->dnr,
-		     shdlc->rnr == false ? "false" : "true",
-		     shdlc->w - nfc_shdlc_w_used(shdlc->ns, shdlc->dnr),
-		     shdlc->ack_pending_q.qlen);
-
-	while (shdlc->send_q.qlen && shdlc->ack_pending_q.qlen < shdlc->w &&
-	       (shdlc->rnr == false)) {
-
-		if (shdlc->t1_active) {
-			del_timer_sync(&shdlc->t1_timer);
-			shdlc->t1_active = false;
-			pr_debug("Stopped T1(send ack)\n");
-		}
-
-		skb = skb_dequeue(&shdlc->send_q);
-
-		*skb_push(skb, 1) = SHDLC_CONTROL_HEAD_I | (shdlc->ns << 3) |
-				    shdlc->nr;
-
-		pr_debug("Sending I-Frame %d, waiting to rcv %d\n", shdlc->ns,
-			 shdlc->nr);
-	/*	SHDLC_DUMP_SKB("shdlc frame written", skb); */
-
-		r = shdlc->ops->xmit(shdlc, skb);
-		if (r < 0) {
-			shdlc->hard_fault = r;
-			break;
-		}
-
-		shdlc->ns = (shdlc->ns + 1) % 8;
-
-		time_sent = jiffies;
-		*(unsigned long *)skb->cb = time_sent;
-
-		skb_queue_tail(&shdlc->ack_pending_q, skb);
-
-		if (shdlc->t2_active == false) {
-			shdlc->t2_active = true;
-			mod_timer(&shdlc->t2_timer, time_sent +
-				  msecs_to_jiffies(SHDLC_T2_VALUE_MS));
-			pr_debug("Started T2 (retransmit)\n");
-		}
-	}
-}
-
-static void nfc_shdlc_connect_timeout(unsigned long data)
-{
-	struct nfc_shdlc *shdlc = (struct nfc_shdlc *)data;
-
-	pr_debug("\n");
-
-	queue_work(system_nrt_wq, &shdlc->sm_work);
-}
-
-static void nfc_shdlc_t1_timeout(unsigned long data)
-{
-	struct nfc_shdlc *shdlc = (struct nfc_shdlc *)data;
-
-	pr_debug("SoftIRQ: need to send ack\n");
-
-	queue_work(system_nrt_wq, &shdlc->sm_work);
-}
-
-static void nfc_shdlc_t2_timeout(unsigned long data)
-{
-	struct nfc_shdlc *shdlc = (struct nfc_shdlc *)data;
-
-	pr_debug("SoftIRQ: need to retransmit\n");
-
-	queue_work(system_nrt_wq, &shdlc->sm_work);
-}
-
-static void nfc_shdlc_sm_work(struct work_struct *work)
-{
-	struct nfc_shdlc *shdlc = container_of(work, struct nfc_shdlc, sm_work);
-	int r;
-
-	pr_debug("\n");
-
-	mutex_lock(&shdlc->state_mutex);
-
-	switch (shdlc->state) {
-	case SHDLC_DISCONNECTED:
-		skb_queue_purge(&shdlc->rcv_q);
-		skb_queue_purge(&shdlc->send_q);
-		skb_queue_purge(&shdlc->ack_pending_q);
-		break;
-	case SHDLC_CONNECTING:
-		if (shdlc->hard_fault) {
-			nfc_shdlc_connect_complete(shdlc, shdlc->hard_fault);
-			break;
-		}
-
-		if (shdlc->connect_tries++ < 5)
-			r = nfc_shdlc_connect_initiate(shdlc);
-		else
-			r = -ETIME;
-		if (r < 0)
-			nfc_shdlc_connect_complete(shdlc, r);
-		else {
-			mod_timer(&shdlc->connect_timer, jiffies +
-				  msecs_to_jiffies(SHDLC_CONNECT_VALUE_MS));
-
-			shdlc->state = SHDLC_NEGOCIATING;
-		}
-		break;
-	case SHDLC_NEGOCIATING:
-		if (timer_pending(&shdlc->connect_timer) == 0) {
-			shdlc->state = SHDLC_CONNECTING;
-			queue_work(system_nrt_wq, &shdlc->sm_work);
-		}
-
-		nfc_shdlc_handle_rcv_queue(shdlc);
-
-		if (shdlc->hard_fault) {
-			nfc_shdlc_connect_complete(shdlc, shdlc->hard_fault);
-			break;
-		}
-		break;
-	case SHDLC_CONNECTED:
-		nfc_shdlc_handle_rcv_queue(shdlc);
-		nfc_shdlc_handle_send_queue(shdlc);
-
-		if (shdlc->t1_active && timer_pending(&shdlc->t1_timer) == 0) {
-			pr_debug
-			    ("Handle T1(send ack) elapsed (T1 now inactive)\n");
-
-			shdlc->t1_active = false;
-			r = nfc_shdlc_send_s_frame(shdlc, S_FRAME_RR,
-						   shdlc->nr);
-			if (r < 0)
-				shdlc->hard_fault = r;
-		}
-
-		if (shdlc->t2_active && timer_pending(&shdlc->t2_timer) == 0) {
-			pr_debug
-			    ("Handle T2(retransmit) elapsed (T2 inactive)\n");
-
-			shdlc->t2_active = false;
-
-			nfc_shdlc_requeue_ack_pending(shdlc);
-			nfc_shdlc_handle_send_queue(shdlc);
-		}
-
-		if (shdlc->hard_fault) {
-			nfc_hci_driver_failure(shdlc->hdev, shdlc->hard_fault);
-		}
-		break;
-	default:
-		break;
-	}
-	mutex_unlock(&shdlc->state_mutex);
-}
-
-/*
- * Called from syscall context to establish shdlc link. Sleeps until
- * link is ready or failure.
- */
-static int nfc_shdlc_connect(struct nfc_shdlc *shdlc)
-{
-	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(connect_wq);
-
-	pr_debug("\n");
-
-	mutex_lock(&shdlc->state_mutex);
-
-	shdlc->state = SHDLC_CONNECTING;
-	shdlc->connect_wq = &connect_wq;
-	shdlc->connect_tries = 0;
-	shdlc->connect_result = 1;
-
-	mutex_unlock(&shdlc->state_mutex);
-
-	queue_work(system_nrt_wq, &shdlc->sm_work);
-
-	wait_event(connect_wq, shdlc->connect_result != 1);
-
-	return shdlc->connect_result;
-}
-
-static void nfc_shdlc_disconnect(struct nfc_shdlc *shdlc)
-{
-	pr_debug("\n");
-
-	mutex_lock(&shdlc->state_mutex);
-
-	shdlc->state = SHDLC_DISCONNECTED;
-
-	mutex_unlock(&shdlc->state_mutex);
-
-	queue_work(system_nrt_wq, &shdlc->sm_work);
-}
-
-/*
- * Receive an incoming shdlc frame. Frame has already been crc-validated.
- * skb contains only LLC header and payload.
- * If skb == NULL, it is a notification that the link below is dead.
- */
-void nfc_shdlc_recv_frame(struct nfc_shdlc *shdlc, struct sk_buff *skb)
-{
-	if (skb == NULL) {
-		pr_err("NULL Frame -> link is dead\n");
-		shdlc->hard_fault = -EREMOTEIO;
-	} else {
-		SHDLC_DUMP_SKB("incoming frame", skb);
-		skb_queue_tail(&shdlc->rcv_q, skb);
-	}
-
-	queue_work(system_nrt_wq, &shdlc->sm_work);
-}
-EXPORT_SYMBOL(nfc_shdlc_recv_frame);
-
-static int nfc_shdlc_open(struct nfc_hci_dev *hdev)
-{
-	struct nfc_shdlc *shdlc = nfc_hci_get_clientdata(hdev);
-	int r;
-
-	pr_debug("\n");
-
-	if (shdlc->ops->open) {
-		r = shdlc->ops->open(shdlc);
-		if (r < 0)
-			return r;
-	}
-
-	r = nfc_shdlc_connect(shdlc);
-	if (r < 0 && shdlc->ops->close)
-		shdlc->ops->close(shdlc);
-
-	return r;
-}
-
-static void nfc_shdlc_close(struct nfc_hci_dev *hdev)
-{
-	struct nfc_shdlc *shdlc = nfc_hci_get_clientdata(hdev);
-
-	pr_debug("\n");
-
-	nfc_shdlc_disconnect(shdlc);
-
-	if (shdlc->ops->close)
-		shdlc->ops->close(shdlc);
-}
-
-static int nfc_shdlc_hci_ready(struct nfc_hci_dev *hdev)
-{
-	struct nfc_shdlc *shdlc = nfc_hci_get_clientdata(hdev);
-	int r = 0;
-
-	pr_debug("\n");
-
-	if (shdlc->ops->hci_ready)
-		r = shdlc->ops->hci_ready(shdlc);
-
-	return r;
-}
-
-static int nfc_shdlc_xmit(struct nfc_hci_dev *hdev, struct sk_buff *skb)
-{
-	struct nfc_shdlc *shdlc = nfc_hci_get_clientdata(hdev);
-
-	SHDLC_DUMP_SKB("queuing HCP packet to shdlc", skb);
-
-	skb_queue_tail(&shdlc->send_q, skb);
-
-	queue_work(system_nrt_wq, &shdlc->sm_work);
-
-	return 0;
-}
-
-static int nfc_shdlc_start_poll(struct nfc_hci_dev *hdev,
-				u32 im_protocols, u32 tm_protocols)
-{
-	struct nfc_shdlc *shdlc = nfc_hci_get_clientdata(hdev);
-
-	pr_debug("\n");
-
-	if (shdlc->ops->start_poll)
-		return shdlc->ops->start_poll(shdlc,
-					      im_protocols, tm_protocols);
-
-	return 0;
-}
-
-static int nfc_shdlc_target_from_gate(struct nfc_hci_dev *hdev, u8 gate,
-				      struct nfc_target *target)
-{
-	struct nfc_shdlc *shdlc = nfc_hci_get_clientdata(hdev);
-
-	if (shdlc->ops->target_from_gate)
-		return shdlc->ops->target_from_gate(shdlc, gate, target);
-
-	return -EPERM;
-}
-
-static int nfc_shdlc_complete_target_discovered(struct nfc_hci_dev *hdev,
-						u8 gate,
-						struct nfc_target *target)
-{
-	struct nfc_shdlc *shdlc = nfc_hci_get_clientdata(hdev);
-
-	pr_debug("\n");
-
-	if (shdlc->ops->complete_target_discovered)
-		return shdlc->ops->complete_target_discovered(shdlc, gate,
-							      target);
-
-	return 0;
-}
-
-static int nfc_shdlc_data_exchange(struct nfc_hci_dev *hdev,
-				   struct nfc_target *target,
-				   struct sk_buff *skb,
-				   data_exchange_cb_t cb, void *cb_context)
-{
-	struct nfc_shdlc *shdlc = nfc_hci_get_clientdata(hdev);
-
-	if (shdlc->ops->data_exchange)
-		return shdlc->ops->data_exchange(shdlc, target, skb, cb,
-						 cb_context);
-
-	return -EPERM;
-}
-
-static int nfc_shdlc_check_presence(struct nfc_hci_dev *hdev,
-				    struct nfc_target *target)
-{
-	struct nfc_shdlc *shdlc = nfc_hci_get_clientdata(hdev);
-
-	if (shdlc->ops->check_presence)
-		return shdlc->ops->check_presence(shdlc, target);
-
-	return 0;
-}
-
-static struct nfc_hci_ops shdlc_ops = {
-	.open = nfc_shdlc_open,
-	.close = nfc_shdlc_close,
-	.hci_ready = nfc_shdlc_hci_ready,
-	.xmit = nfc_shdlc_xmit,
-	.start_poll = nfc_shdlc_start_poll,
-	.target_from_gate = nfc_shdlc_target_from_gate,
-	.complete_target_discovered = nfc_shdlc_complete_target_discovered,
-	.data_exchange = nfc_shdlc_data_exchange,
-	.check_presence = nfc_shdlc_check_presence,
-};
-
-struct nfc_shdlc *nfc_shdlc_allocate(struct nfc_shdlc_ops *ops,
-				     struct nfc_hci_init_data *init_data,
-				     u32 protocols,
-				     int tx_headroom, int tx_tailroom,
-				     int max_link_payload, const char *devname)
-{
-	struct nfc_shdlc *shdlc;
-	int r;
-
-	if (ops->xmit == NULL)
-		return NULL;
-
-	shdlc = kzalloc(sizeof(struct nfc_shdlc), GFP_KERNEL);
-	if (shdlc == NULL)
-		return NULL;
-
-	mutex_init(&shdlc->state_mutex);
-	shdlc->ops = ops;
-	shdlc->state = SHDLC_DISCONNECTED;
-
-	init_timer(&shdlc->connect_timer);
-	shdlc->connect_timer.data = (unsigned long)shdlc;
-	shdlc->connect_timer.function = nfc_shdlc_connect_timeout;
-
-	init_timer(&shdlc->t1_timer);
-	shdlc->t1_timer.data = (unsigned long)shdlc;
-	shdlc->t1_timer.function = nfc_shdlc_t1_timeout;
-
-	init_timer(&shdlc->t2_timer);
-	shdlc->t2_timer.data = (unsigned long)shdlc;
-	shdlc->t2_timer.function = nfc_shdlc_t2_timeout;
-
-	shdlc->w = SHDLC_MAX_WINDOW;
-	shdlc->srej_support = SHDLC_SREJ_SUPPORT;
-
-	skb_queue_head_init(&shdlc->rcv_q);
-	skb_queue_head_init(&shdlc->send_q);
-	skb_queue_head_init(&shdlc->ack_pending_q);
-
-	INIT_WORK(&shdlc->sm_work, nfc_shdlc_sm_work);
-
-	shdlc->client_headroom = tx_headroom;
-	shdlc->client_tailroom = tx_tailroom;
-
-	shdlc->hdev = nfc_hci_allocate_device(&shdlc_ops, init_data, protocols,
-					      tx_headroom + SHDLC_LLC_HEAD_ROOM,
-					      tx_tailroom,
-					      max_link_payload);
-	if (shdlc->hdev == NULL)
-		goto err_allocdev;
-
-	nfc_hci_set_clientdata(shdlc->hdev, shdlc);
-
-	r = nfc_hci_register_device(shdlc->hdev);
-	if (r < 0)
-		goto err_regdev;
-
-	return shdlc;
-
-err_regdev:
-	nfc_hci_free_device(shdlc->hdev);
-
-err_allocdev:
-	kfree(shdlc);
-
-	return NULL;
-}
-EXPORT_SYMBOL(nfc_shdlc_allocate);
-
-void nfc_shdlc_free(struct nfc_shdlc *shdlc)
-{
-	pr_debug("\n");
-
-	nfc_hci_unregister_device(shdlc->hdev);
-	nfc_hci_free_device(shdlc->hdev);
-
-	cancel_work_sync(&shdlc->sm_work);
-
-	skb_queue_purge(&shdlc->rcv_q);
-	skb_queue_purge(&shdlc->send_q);
-	skb_queue_purge(&shdlc->ack_pending_q);
-
-	kfree(shdlc);
-}
-EXPORT_SYMBOL(nfc_shdlc_free);
-
-void nfc_shdlc_set_clientdata(struct nfc_shdlc *shdlc, void *clientdata)
-{
-	pr_debug("\n");
-
-	shdlc->clientdata = clientdata;
-}
-EXPORT_SYMBOL(nfc_shdlc_set_clientdata);
-
-void *nfc_shdlc_get_clientdata(struct nfc_shdlc *shdlc)
-{
-	return shdlc->clientdata;
-}
-EXPORT_SYMBOL(nfc_shdlc_get_clientdata);
-
-struct nfc_hci_dev *nfc_shdlc_get_hci_dev(struct nfc_shdlc *shdlc)
-{
-	return shdlc->hdev;
-}
-EXPORT_SYMBOL(nfc_shdlc_get_hci_dev);