nfc: st21nfca: Add additional comments about EVT_TRANSACTION

Add comments about HCI EVT_TRANSACTION in order to make the code
understandable by other readers.

Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This commit is contained in:
Christophe Ricard 2015-03-31 08:02:23 +02:00 committed by Samuel Ortiz
parent 1dab57f0ed
commit 9dbe776338
1 changed files with 10 additions and 1 deletions

View File

@ -310,6 +310,13 @@ int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host,
case ST21NFCA_EVT_CONNECTIVITY:
break;
case ST21NFCA_EVT_TRANSACTION:
/*
* According to specification etsi 102 622
* 11.2.2.4 EVT_TRANSACTION Table 52
* Description Tag Length
* AID 81 5 to 16
* PARAMETERS 82 0 to 255
*/
if (skb->len < NFC_MIN_AID_LENGTH + 2 &&
skb->data[0] != NFC_EVT_TRANSACTION_AID_TAG)
return -EPROTO;
@ -318,8 +325,10 @@ int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host,
skb->len - 2, GFP_KERNEL);
transaction->aid_len = skb->data[1];
memcpy(transaction->aid, &skb->data[2], skb->data[1]);
memcpy(transaction->aid, &skb->data[2],
transaction->aid_len);
/* Check next byte is PARAMETERS tag (82) */
if (skb->data[transaction->aid_len + 2] !=
NFC_EVT_TRANSACTION_PARAMS_TAG)
return -EPROTO;