1 files changed, 251 insertions, 0 deletions
diff --git a/net/nfc/nci/data.c b/net/nfc/nci/data.c
new file mode 100644
index 00000000000..6c3aef85287
--- /dev/null
+++ b/net/nfc/nci/data.c
@@ -0,0 +1,251 @@
+/*
+ *  The NFC Controller Interface is the communication protocol between an
+ *  NFC Controller (NFCC) and a Device Host (DH).
+ *
+ *  Copyright (C) 2011 Texas Instruments, Inc.
+ *
+ *  Written by Ilan Elias <ilane@ti.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms 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/>.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
+
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/wait.h>
+#include <linux/bitops.h>
+#include <linux/skbuff.h>
+
+#include "../nfc.h"
+#include <net/nfc/nci.h>
+#include <net/nfc/nci_core.h>
+#include <linux/nfc.h>
+
+/* Complete data exchange transaction and forward skb to nfc core */
+void nci_data_exchange_complete(struct nci_dev *ndev, struct sk_buff *skb,
+				int err)
+{
+	data_exchange_cb_t cb = ndev->data_exchange_cb;
+	void *cb_context = ndev->data_exchange_cb_context;
+
+	pr_debug("len %d, err %d\n", skb ? skb->len : 0, err);
+
+	/* data exchange is complete, stop the data timer */
+	del_timer_sync(&ndev->data_timer);
+	clear_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags);
+
+	if (cb) {
+		ndev->data_exchange_cb = NULL;
+		ndev->data_exchange_cb_context = NULL;
+
+		/* forward skb to nfc core */
+		cb(cb_context, skb, err);
+	} else if (skb) {
+		pr_err("no rx callback, dropping rx data...\n");
+
+		/* no waiting callback, free skb */
+		kfree_skb(skb);
+	}
+
+	clear_bit(NCI_DATA_EXCHANGE, &ndev->flags);
+}
+
+/* ----------------- NCI TX Data ----------------- */
+
+static inline void nci_push_data_hdr(struct nci_dev *ndev,
+				     __u8 conn_id,
+				     struct sk_buff *skb,
+				     __u8 pbf)
+{
+	struct nci_data_hdr *hdr;
+	int plen = skb->len;
+
+	hdr = (struct nci_data_hdr *) skb_push(skb, NCI_DATA_HDR_SIZE);
+	hdr->conn_id = conn_id;
+	hdr->rfu = 0;
+	hdr->plen = plen;
+
+	nci_mt_set((__u8 *)hdr, NCI_MT_DATA_PKT);
+	nci_pbf_set((__u8 *)hdr, pbf);
+}
+
+static int nci_queue_tx_data_frags(struct nci_dev *ndev,
+				   __u8 conn_id,
+				   struct sk_buff *skb) {
+	int total_len = skb->len;
+	unsigned char *data = skb->data;
+	unsigned long flags;
+	struct sk_buff_head frags_q;
+	struct sk_buff *skb_frag;
+	int frag_len;
+	int rc = 0;
+
+	pr_debug("conn_id 0x%x, total_len %d\n", conn_id, total_len);
+
+	__skb_queue_head_init(&frags_q);
+
+	while (total_len) {
+		frag_len =
+			min_t(int, total_len, ndev->max_data_pkt_payload_size);
+
+		skb_frag = nci_skb_alloc(ndev,
+					 (NCI_DATA_HDR_SIZE + frag_len),
+					 GFP_KERNEL);
+		if (skb_frag == NULL) {
+			rc = -ENOMEM;
+			goto free_exit;
+		}
+		skb_reserve(skb_frag, NCI_DATA_HDR_SIZE);
+
+		/* first, copy the data */
+		memcpy(skb_put(skb_frag, frag_len), data, frag_len);
+
+		/* second, set the header */
+		nci_push_data_hdr(ndev, conn_id, skb_frag,
+				  ((total_len == frag_len) ?
+				   (NCI_PBF_LAST) : (NCI_PBF_CONT)));
+
+		__skb_queue_tail(&frags_q, skb_frag);
+
+		data += frag_len;
+		total_len -= frag_len;
+
+		pr_debug("frag_len %d, remaining total_len %d\n",
+			 frag_len, total_len);
+	}
+
+	/* queue all fragments atomically */
+	spin_lock_irqsave(&ndev->tx_q.lock, flags);
+
+	while ((skb_frag = __skb_dequeue(&frags_q)) != NULL)
+		__skb_queue_tail(&ndev->tx_q, skb_frag);
+
+	spin_unlock_irqrestore(&ndev->tx_q.lock, flags);
+
+	/* free the original skb */
+	kfree_skb(skb);
+
+	goto exit;
+
+free_exit:
+	while ((skb_frag = __skb_dequeue(&frags_q)) != NULL)
+		kfree_skb(skb_frag);
+
+exit:
+	return rc;
+}
+
+/* Send NCI data */
+int nci_send_data(struct nci_dev *ndev, __u8 conn_id, struct sk_buff *skb)
+{
+	int rc = 0;
+
+	pr_debug("conn_id 0x%x, plen %d\n", conn_id, skb->len);
+
+	/* check if the packet need to be fragmented */
+	if (skb->len <= ndev->max_data_pkt_payload_size) {
+		/* no need to fragment packet */
+		nci_push_data_hdr(ndev, conn_id, skb, NCI_PBF_LAST);
+
+		skb_queue_tail(&ndev->tx_q, skb);
+	} else {
+		/* fragment packet and queue the fragments */
+		rc = nci_queue_tx_data_frags(ndev, conn_id, skb);
+		if (rc) {
+			pr_err("failed to fragment tx data packet\n");
+			goto free_exit;
+		}
+	}
+
+	queue_work(ndev->tx_wq, &ndev->tx_work);
+
+	goto exit;
+
+free_exit:
+	kfree_skb(skb);
+
+exit:
+	return rc;
+}
+
+/* ----------------- NCI RX Data ----------------- */
+
+static void nci_add_rx_data_frag(struct nci_dev *ndev,
+				 struct sk_buff *skb,
+				 __u8 pbf)
+{
+	int reassembly_len;
+	int err = 0;
+
+	if (ndev->rx_data_reassembly) {
+		reassembly_len = ndev->rx_data_reassembly->len;
+
+		/* first, make enough room for the already accumulated data */
+		if (skb_cow_head(skb, reassembly_len)) {
+			pr_err("error adding room for accumulated rx data\n");
+
+			kfree_skb(skb);
+			skb = NULL;
+
+			kfree_skb(ndev->rx_data_reassembly);
+			ndev->rx_data_reassembly = NULL;
+
+			err = -ENOMEM;
+			goto exit;
+		}
+
+		/* second, combine the two fragments */
+		memcpy(skb_push(skb, reassembly_len),
+		       ndev->rx_data_reassembly->data,
+		       reassembly_len);
+
+		/* third, free old reassembly */
+		kfree_skb(ndev->rx_data_reassembly);
+		ndev->rx_data_reassembly = NULL;
+	}
+
+	if (pbf == NCI_PBF_CONT) {
+		/* need to wait for next fragment, store skb and exit */
+		ndev->rx_data_reassembly = skb;
+		return;
+	}
+
+exit:
+	nci_data_exchange_complete(ndev, skb, err);
+}
+
+/* Rx Data packet */
+void nci_rx_data_packet(struct nci_dev *ndev, struct sk_buff *skb)
+{
+	__u8 pbf = nci_pbf(skb->data);
+
+	pr_debug("len %d\n", skb->len);
+
+	pr_debug("NCI RX: MT=data, PBF=%d, conn_id=%d, plen=%d\n",
+		 nci_pbf(skb->data),
+		 nci_conn_id(skb->data),
+		 nci_plen(skb->data));
+
+	/* strip the nci data header */
+	skb_pull(skb, NCI_DATA_HDR_SIZE);
+
+	if (ndev->target_active_prot == NFC_PROTO_MIFARE) {
+		/* frame I/F => remove the status byte */
+		pr_debug("NFC_PROTO_MIFARE => remove the status byte\n");
+		skb_trim(skb, (skb->len - 1));
+	}
+
+	nci_add_rx_data_frag(ndev, skb, pbf);
+}