NFC: digital: Add NFC-DEP Target-side ATN Support
When an NFC-DEP target receives an ATN PDU, its
supposed to respond with a similar ATN PDU.
When the Target receives an I PDU with the PNI
one less than the current PNI and the last PDU
sent was an ATN PDU, the Target is to resend the
last non-ATN PDU that it has sent. This is
described in section 14.12.3.4 of the NFC Digital
Protocol Spec.
The digital layer's NFC-DEP code doesn't implement
this so add that support.
Reviewed-by: Thierry Escande <thierry.escande@linux.intel.com>
Tested-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/net/nfc/digital_dep.c b/net/nfc/digital_dep.c
index 8f1fefd..f72be74 100644
--- a/net/nfc/digital_dep.c
+++ b/net/nfc/digital_dep.c
@@ -970,6 +970,43 @@
return rc;
}
+static int digital_tg_send_atn(struct nfc_digital_dev *ddev)
+{
+ struct digital_dep_req_res *dep_res;
+ struct sk_buff *skb;
+ int rc;
+
+ skb = digital_skb_alloc(ddev, 1);
+ if (!skb)
+ return -ENOMEM;
+
+ skb_push(skb, sizeof(struct digital_dep_req_res));
+
+ dep_res = (struct digital_dep_req_res *)skb->data;
+
+ dep_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN;
+ dep_res->cmd = DIGITAL_CMD_DEP_RES;
+ dep_res->pfb = DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU;
+
+ if (ddev->did) {
+ dep_res->pfb |= DIGITAL_NFC_DEP_PFB_DID_BIT;
+
+ memcpy(skb_put(skb, sizeof(ddev->did)), &ddev->did,
+ sizeof(ddev->did));
+ }
+
+ digital_skb_push_dep_sod(ddev, skb);
+
+ ddev->skb_add_crc(skb);
+
+ rc = digital_tg_send_cmd(ddev, skb, 1500, digital_tg_recv_dep_req,
+ NULL);
+ if (rc)
+ kfree_skb(skb);
+
+ return rc;
+}
+
static int digital_tg_send_saved_skb(struct nfc_digital_dev *ddev)
{
skb_get(ddev->saved_skb);
@@ -1049,12 +1086,24 @@
case DIGITAL_NFC_DEP_PFB_I_PDU:
pr_debug("DIGITAL_NFC_DEP_PFB_I_PDU\n");
- if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) {
+ if ((ddev->atn_count && (DIGITAL_NFC_DEP_PFB_PNI(pfb - 1) !=
+ ddev->curr_nfc_dep_pni)) ||
+ (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni)) {
PROTOCOL_ERR("14.12.3.4");
rc = -EIO;
goto exit;
}
+ if (ddev->atn_count) {
+ ddev->atn_count = 0;
+
+ rc = digital_tg_send_saved_skb(ddev);
+ if (rc)
+ goto exit;
+
+ return;
+ }
+
kfree_skb(ddev->saved_skb);
ddev->saved_skb = NULL;
@@ -1077,13 +1126,26 @@
break;
case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU:
if (!DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) { /* ACK */
- if ((DIGITAL_NFC_DEP_PFB_PNI(pfb) !=
+ if ((ddev->atn_count &&
+ (DIGITAL_NFC_DEP_PFB_PNI(pfb - 1) !=
+ ddev->curr_nfc_dep_pni)) ||
+ (DIGITAL_NFC_DEP_PFB_PNI(pfb) !=
ddev->curr_nfc_dep_pni) ||
!ddev->chaining_skb || !ddev->saved_skb) {
rc = -EIO;
goto exit;
}
+ if (ddev->atn_count) {
+ ddev->atn_count = 0;
+
+ rc = digital_tg_send_saved_skb(ddev);
+ if (rc)
+ goto exit;
+
+ return;
+ }
+
kfree_skb(ddev->saved_skb);
ddev->saved_skb = NULL;
@@ -1098,6 +1160,8 @@
goto exit;
}
+ ddev->atn_count = 0;
+
rc = digital_tg_send_saved_skb(ddev);
if (rc) {
kfree_skb(ddev->saved_skb);
@@ -1107,9 +1171,19 @@
return;
case DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU:
- pr_err("Received a SUPERVISOR PDU\n");
- rc = -EINVAL;
- goto exit;
+ if (DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb)) {
+ rc = -EINVAL;
+ goto exit;
+ }
+
+ rc = digital_tg_send_atn(ddev);
+ if (rc)
+ goto exit;
+
+ ddev->atn_count++;
+
+ kfree_skb(resp);
+ return;
}
rc = nfc_tm_data_received(ddev->nfc_dev, resp);
@@ -1118,6 +1192,8 @@
kfree_skb(ddev->chaining_skb);
ddev->chaining_skb = NULL;
+ ddev->atn_count = 0;
+
kfree_skb(ddev->saved_skb);
ddev->saved_skb = NULL;
@@ -1311,6 +1387,8 @@
if (resp->data[0] == DIGITAL_NFC_DEP_NFCA_SOD_SB)
offset++;
+ ddev->atn_count = 0;
+
if (resp->data[offset] == DIGITAL_CMD_PSL_REQ)
digital_tg_recv_psl_req(ddev, arg, resp);
else
