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authorMark A. Greer <mgreer@animalcreek.com>2014-09-23 16:38:13 -0700
committerSamuel Ortiz <sameo@linux.intel.com>2014-11-28 12:39:55 +0100
commit384ab1d174a11292af63674a26eaa99864db9b48 (patch)
tree92330bc261e79bc6788543930e590f0fed706b63
parent49dbb14e30c3249f98fe243c3e21b91d10c5c59b (diff)
downloadlinux-384ab1d174a11292af63674a26eaa99864db9b48.tar.bz2
NFC: digital: Add NFC-DEP Initiator-side ATN Support
When an NFC-DEP Initiator times out when waiting for a DEP_RES from the Target, its supposed to send an ATN to the Target. The Target should respond to the ATN with a similar ATN PDU and the Initiator can then resend the last non-ATN PDU that it sent. No more than 'N(retry,atn)' are to be send where 2 <= 'N(retry,atn)' <= 5. If the Initiator had just sent a NACK PDU when the timeout occurred, it is to continue sending NACKs until 'N(retry,nack)' NACKs have been send. This is described in section 14.12.5.6 of the NFC-DEP Digital Protocol Spec. The digital layer's NFC-DEP code doesn't implement this so add that support. The value chosen for 'N(retry,atn)' is 2. 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>
-rw-r--r--include/net/nfc/digital.h1
-rw-r--r--net/nfc/digital_dep.c104
2 files changed, 99 insertions, 6 deletions
diff --git a/include/net/nfc/digital.h b/include/net/nfc/digital.h
index 7400a8126cd1..0ae101eef0f4 100644
--- a/include/net/nfc/digital.h
+++ b/include/net/nfc/digital.h
@@ -233,6 +233,7 @@ struct nfc_digital_dev {
struct sk_buff *chaining_skb;
struct digital_data_exch *data_exch;
+ int atn_count;
int nack_count;
struct sk_buff *saved_skb;
diff --git a/net/nfc/digital_dep.c b/net/nfc/digital_dep.c
index 31418edbe78e..8f1fefd2ed14 100644
--- a/net/nfc/digital_dep.c
+++ b/net/nfc/digital_dep.c
@@ -18,6 +18,7 @@
#include "digital.h"
#define DIGITAL_NFC_DEP_N_RETRY_NACK 2
+#define DIGITAL_NFC_DEP_N_RETRY_ATN 2
#define DIGITAL_NFC_DEP_FRAME_DIR_OUT 0xD4
#define DIGITAL_NFC_DEP_FRAME_DIR_IN 0xD5
@@ -523,10 +524,16 @@ static int digital_in_send_ack(struct nfc_digital_dev *ddev,
ddev->skb_add_crc(skb);
+ ddev->saved_skb = skb_get(skb);
+ ddev->saved_skb_len = skb->len;
+
rc = digital_in_send_cmd(ddev, skb, 1500, digital_in_recv_dep_res,
data_exch);
- if (rc)
+ if (rc) {
kfree_skb(skb);
+ kfree_skb(ddev->saved_skb);
+ ddev->saved_skb = NULL;
+ }
return rc;
}
@@ -563,6 +570,37 @@ static int digital_in_send_nack(struct nfc_digital_dev *ddev,
return rc;
}
+static int digital_in_send_atn(struct nfc_digital_dev *ddev,
+ struct digital_data_exch *data_exch)
+{
+ struct digital_dep_req_res *dep_req;
+ 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_req = (struct digital_dep_req_res *)skb->data;
+
+ dep_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT;
+ dep_req->cmd = DIGITAL_CMD_DEP_REQ;
+ dep_req->pfb = DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU;
+
+ digital_skb_push_dep_sod(ddev, skb);
+
+ ddev->skb_add_crc(skb);
+
+ rc = digital_in_send_cmd(ddev, skb, 1500, digital_in_recv_dep_res,
+ data_exch);
+ if (rc)
+ kfree_skb(skb);
+
+ return rc;
+}
+
static int digital_in_send_rtox(struct nfc_digital_dev *ddev,
struct digital_data_exch *data_exch, u8 rtox)
{
@@ -589,14 +627,30 @@ static int digital_in_send_rtox(struct nfc_digital_dev *ddev,
ddev->skb_add_crc(skb);
+ ddev->saved_skb = skb_get(skb);
+ ddev->saved_skb_len = skb->len;
+
rc = digital_in_send_cmd(ddev, skb, 1500, digital_in_recv_dep_res,
data_exch);
- if (rc)
+ if (rc) {
kfree_skb(skb);
+ kfree_skb(ddev->saved_skb);
+ ddev->saved_skb = NULL;
+ }
return rc;
}
+static int digital_in_send_saved_skb(struct nfc_digital_dev *ddev,
+ struct digital_data_exch *data_exch)
+{
+ skb_get(ddev->saved_skb);
+ skb_push(ddev->saved_skb, ddev->saved_skb_len);
+
+ return digital_in_send_cmd(ddev, ddev->saved_skb, 1500,
+ digital_in_recv_dep_res, data_exch);
+}
+
static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
struct sk_buff *resp)
{
@@ -610,13 +664,24 @@ static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
rc = PTR_ERR(resp);
resp = NULL;
- if ((rc != -ETIMEDOUT) &&
+ if (((rc != -ETIMEDOUT) || ddev->nack_count) &&
(ddev->nack_count++ < DIGITAL_NFC_DEP_N_RETRY_NACK)) {
+ ddev->atn_count = 0;
+
rc = digital_in_send_nack(ddev, data_exch);
if (rc)
goto error;
return;
+ } else if ((rc == -ETIMEDOUT) &&
+ (ddev->atn_count++ < DIGITAL_NFC_DEP_N_RETRY_ATN)) {
+ ddev->nack_count = 0;
+
+ rc = digital_in_send_atn(ddev, data_exch);
+ if (rc)
+ goto error;
+
+ return;
}
goto exit;
@@ -632,6 +697,8 @@ static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
if (rc) {
if ((resp->len >= 4) &&
(ddev->nack_count++ < DIGITAL_NFC_DEP_N_RETRY_NACK)) {
+ ddev->atn_count = 0;
+
rc = digital_in_send_nack(ddev, data_exch);
if (rc)
goto error;
@@ -645,6 +712,7 @@ static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
goto error;
}
+ ddev->atn_count = 0;
ddev->nack_count = 0;
if (resp->len > ddev->local_payload_max) {
@@ -692,6 +760,9 @@ static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
ddev->curr_nfc_dep_pni =
DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1);
+ kfree_skb(ddev->saved_skb);
+ ddev->saved_skb = NULL;
+
resp = digital_recv_dep_data_gather(ddev, pfb, resp,
digital_in_send_ack,
data_exch);
@@ -722,6 +793,9 @@ static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1);
if (ddev->chaining_skb && !DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) {
+ kfree_skb(ddev->saved_skb);
+ ddev->saved_skb = NULL;
+
rc = digital_in_send_dep_req(ddev, NULL,
ddev->chaining_skb,
ddev->data_exch);
@@ -736,11 +810,19 @@ static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
goto exit;
case DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU:
- if (!DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb)) {
- rc = -EINVAL;
- goto error;
+ if (!DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb)) { /* ATN */
+ rc = digital_in_send_saved_skb(ddev, data_exch);
+ if (rc) {
+ kfree_skb(ddev->saved_skb);
+ goto error;
+ }
+
+ return;
}
+ kfree_skb(ddev->saved_skb);
+ ddev->saved_skb = NULL;
+
rc = digital_in_send_rtox(ddev, data_exch, resp->data[0]);
if (rc)
goto error;
@@ -758,6 +840,9 @@ error:
kfree_skb(ddev->chaining_skb);
ddev->chaining_skb = NULL;
+ kfree_skb(ddev->saved_skb);
+ ddev->saved_skb = NULL;
+
if (rc)
kfree_skb(resp);
}
@@ -778,6 +863,7 @@ int digital_in_send_dep_req(struct nfc_digital_dev *ddev,
dep_req->cmd = DIGITAL_CMD_DEP_REQ;
dep_req->pfb = ddev->curr_nfc_dep_pni;
+ ddev->atn_count = 0;
ddev->nack_count = 0;
chaining_skb = ddev->chaining_skb;
@@ -790,6 +876,9 @@ int digital_in_send_dep_req(struct nfc_digital_dev *ddev,
ddev->skb_add_crc(tmp_skb);
+ ddev->saved_skb = skb_get(tmp_skb);
+ ddev->saved_skb_len = tmp_skb->len;
+
rc = digital_in_send_cmd(ddev, tmp_skb, 1500, digital_in_recv_dep_res,
data_exch);
if (rc) {
@@ -798,6 +887,9 @@ int digital_in_send_dep_req(struct nfc_digital_dev *ddev,
kfree_skb(chaining_skb);
ddev->chaining_skb = NULL;
+
+ kfree_skb(ddev->saved_skb);
+ ddev->saved_skb = NULL;
}
return rc;