From 1a09c56f545c8ff8d338a38c7c40d79f4165a94c Mon Sep 17 00:00:00 2001 From: Thierry Escande Date: Fri, 8 Jul 2016 15:52:45 +0200 Subject: 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 Signed-off-by: Samuel Ortiz --- net/nfc/digital_dep.c | 71 +++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 55 insertions(+), 16 deletions(-) (limited to 'net/nfc') diff --git a/net/nfc/digital_dep.c b/net/nfc/digital_dep.c index ba52a5dbf3cc..6cf2eeb2e865 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); -- cgit v1.2.3