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authorThierry Escande <thierry.escande@collabora.com>2016-07-08 15:52:45 +0200
committerSamuel Ortiz <sameo@linux.intel.com>2016-07-11 02:01:14 +0200
commit1a09c56f545c8ff8d338a38c7c40d79f4165a94c (patch)
treeb9324ff10a1ecd1432449a18c3aeba9de7b5c330
parente200f008ace69eebac0a1432dc9e24ab5cd0d029 (diff)
NFC: digital: Add support for NFC DEP Response Waiting Time
When sending an ATR_REQ, the initiator must wait for the ATR_RES at least 'RWT(nfcdep,activation) + dRWT(nfcdep)' and no more than 'RWT(nfcdep,activation) + dRWT(nfcdep) + dT(nfcdep,initiator)'. This gives a timeout value between 1237 ms and 1337 ms. This patch defines DIGITAL_ATR_RES_RWT to 1337 used for the timeout value of ATR_REQ command. For other DEP PDUs, the initiator must wait between 'RWT + dRWT(nfcdep)' and 'RWT + dRWT(nfcdep) + dT(nfcdep,initiator)' where RWT is given by the following formula: '(256 * 16 / f(c)) * 2^wt' where wt is the value of the TO field in the ATR_RES response and is in the range between 0 and 14. This patch declares a mapping table for wt values and gives RWT max values between 100 ms and 5049 ms. This patch also defines DIGITAL_ATR_RES_TO_WT, the maximum wt value in target mode, to 8. Signed-off-by: Thierry Escande <thierry.escande@collabora.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.c71
2 files changed, 56 insertions, 16 deletions
diff --git a/include/net/nfc/digital.h b/include/net/nfc/digital.h
index f9a4e47..74fa7eb 100644
--- a/include/net/nfc/digital.h
+++ b/include/net/nfc/digital.h
@@ -226,6 +226,7 @@ struct nfc_digital_dev {
u8 curr_rf_tech;
u8 curr_nfc_dep_pni;
u8 did;
+ u16 dep_rwt;
u8 local_payload_max;
u8 remote_payload_max;
diff --git a/net/nfc/digital_dep.c b/net/nfc/digital_dep.c
index ba52a5d..6cf2eeb 100644
--- a/net/nfc/digital_dep.c
+++ b/net/nfc/digital_dep.c
@@ -35,6 +35,8 @@
#define DIGITAL_ATR_REQ_MIN_SIZE 16
#define DIGITAL_ATR_REQ_MAX_SIZE 64
+#define DIGITAL_ATR_RES_TO_WT(s) ((s) & 0xF)
+
#define DIGITAL_DID_MAX 14
#define DIGITAL_PAYLOAD_SIZE_MAX 254
@@ -122,6 +124,37 @@ static const u8 digital_payload_bits_map[4] = {
[3] = 254
};
+/* Response Waiting Time for ATR_RES PDU in ms
+ *
+ * RWT(ATR_RES) = RWT(nfcdep,activation) + dRWT(nfcdep) + dT(nfcdep,initiator)
+ *
+ * with:
+ * RWT(nfcdep,activation) = 4096 * 2^12 / f(c) s
+ * dRWT(nfcdep) = 16 / f(c) s
+ * dT(nfcdep,initiator) = 100 ms
+ * f(c) = 13560000 Hz
+ */
+#define DIGITAL_ATR_RES_RWT 1337
+
+/* Response Waiting Time for other DEP PDUs in ms
+ *
+ * max_rwt = rwt + dRWT(nfcdep) + dT(nfcdep,initiator)
+ *
+ * with:
+ * rwt = (256 * 16 / f(c)) * 2^wt s
+ * dRWT(nfcdep) = 16 / f(c) s
+ * dT(nfcdep,initiator) = 100 ms
+ * f(c) = 13560000 Hz
+ * 0 <= wt <= 14 (given by the target by the TO field of ATR_RES response)
+ */
+#define DIGITAL_NFC_DEP_IN_MAX_WT 14
+#define DIGITAL_NFC_DEP_TG_MAX_WT 8
+static const u16 digital_rwt_map[DIGITAL_NFC_DEP_IN_MAX_WT + 1] = {
+ 100, 101, 101, 102, 105,
+ 110, 119, 139, 177, 255,
+ 409, 719, 1337, 2575, 5049,
+};
+
static u8 digital_payload_bits_to_size(u8 payload_bits)
{
if (payload_bits >= ARRAY_SIZE(digital_payload_bits_map))
@@ -366,8 +399,8 @@ static int digital_in_send_psl_req(struct nfc_digital_dev *ddev,
ddev->skb_add_crc(skb);
- rc = digital_in_send_cmd(ddev, skb, 500, digital_in_recv_psl_res,
- target);
+ rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt,
+ digital_in_recv_psl_res, target);
if (rc)
kfree_skb(skb);
@@ -380,6 +413,7 @@ static void digital_in_recv_atr_res(struct nfc_digital_dev *ddev, void *arg,
struct nfc_target *target = arg;
struct digital_atr_res *atr_res;
u8 gb_len, payload_bits;
+ u8 wt;
int rc;
if (IS_ERR(resp)) {
@@ -409,6 +443,11 @@ static void digital_in_recv_atr_res(struct nfc_digital_dev *ddev, void *arg,
atr_res = (struct digital_atr_res *)resp->data;
+ wt = DIGITAL_ATR_RES_TO_WT(atr_res->to);
+ if (wt > DIGITAL_NFC_DEP_IN_MAX_WT)
+ wt = DIGITAL_NFC_DEP_IN_MAX_WT;
+ ddev->dep_rwt = digital_rwt_map[wt];
+
payload_bits = DIGITAL_PAYLOAD_PP_TO_BITS(atr_res->pp);
ddev->remote_payload_max = digital_payload_bits_to_size(payload_bits);
@@ -490,8 +529,8 @@ int digital_in_send_atr_req(struct nfc_digital_dev *ddev,
ddev->skb_add_crc(skb);
- rc = digital_in_send_cmd(ddev, skb, 500, digital_in_recv_atr_res,
- target);
+ rc = digital_in_send_cmd(ddev, skb, DIGITAL_ATR_RES_RWT,
+ digital_in_recv_atr_res, target);
if (rc)
kfree_skb(skb);
@@ -524,8 +563,8 @@ static int digital_in_send_ack(struct nfc_digital_dev *ddev,
ddev->saved_skb = pskb_copy(skb, GFP_KERNEL);
- rc = digital_in_send_cmd(ddev, skb, 1500, digital_in_recv_dep_res,
- data_exch);
+ rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt,
+ digital_in_recv_dep_res, data_exch);
if (rc) {
kfree_skb(skb);
kfree_skb(ddev->saved_skb);
@@ -559,8 +598,8 @@ static int digital_in_send_nack(struct nfc_digital_dev *ddev,
ddev->skb_add_crc(skb);
- rc = digital_in_send_cmd(ddev, skb, 1500, digital_in_recv_dep_res,
- data_exch);
+ rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt,
+ digital_in_recv_dep_res, data_exch);
if (rc)
kfree_skb(skb);
@@ -590,8 +629,8 @@ static int digital_in_send_atn(struct nfc_digital_dev *ddev,
ddev->skb_add_crc(skb);
- rc = digital_in_send_cmd(ddev, skb, 1500, digital_in_recv_dep_res,
- data_exch);
+ rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt,
+ digital_in_recv_dep_res, data_exch);
if (rc)
kfree_skb(skb);
@@ -624,8 +663,8 @@ static int digital_in_send_rtox(struct nfc_digital_dev *ddev,
ddev->skb_add_crc(skb);
- rc = digital_in_send_cmd(ddev, skb, 1500, digital_in_recv_dep_res,
- data_exch);
+ rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt,
+ digital_in_recv_dep_res, data_exch);
if (rc)
kfree_skb(skb);
@@ -642,7 +681,7 @@ static int digital_in_send_saved_skb(struct nfc_digital_dev *ddev,
skb_get(ddev->saved_skb);
- rc = digital_in_send_cmd(ddev, ddev->saved_skb, 1500,
+ rc = digital_in_send_cmd(ddev, ddev->saved_skb, ddev->dep_rwt,
digital_in_recv_dep_res, data_exch);
if (rc)
kfree_skb(ddev->saved_skb);
@@ -885,8 +924,8 @@ int digital_in_send_dep_req(struct nfc_digital_dev *ddev,
ddev->saved_skb = pskb_copy(tmp_skb, GFP_KERNEL);
- rc = digital_in_send_cmd(ddev, tmp_skb, 1500, digital_in_recv_dep_res,
- data_exch);
+ rc = digital_in_send_cmd(ddev, tmp_skb, ddev->dep_rwt,
+ digital_in_recv_dep_res, data_exch);
if (rc) {
if (tmp_skb != skb)
kfree_skb(tmp_skb);
@@ -1465,7 +1504,7 @@ static int digital_tg_send_atr_res(struct nfc_digital_dev *ddev,
atr_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN;
atr_res->cmd = DIGITAL_CMD_ATR_RES;
memcpy(atr_res->nfcid3, atr_req->nfcid3, sizeof(atr_req->nfcid3));
- atr_res->to = 8;
+ atr_res->to = DIGITAL_NFC_DEP_TG_MAX_WT;
ddev->local_payload_max = DIGITAL_PAYLOAD_SIZE_MAX;
payload_bits = digital_payload_size_to_bits(ddev->local_payload_max);