From: Mark A. Greer Date: Tue, 23 Sep 2014 23:38:13 +0000 (-0700) Subject: NFC: digital: Add NFC-DEP Initiator-side ATN Support X-Git-Tag: omap-for-v3.19/fixes-rc1~125^2~28^2~16^2~38 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=384ab1d174a11292af63674a26eaa99864db9b48;p=pandora-kernel.git 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 Tested-by: Thierry Escande Signed-off-by: Mark A. Greer Signed-off-by: Samuel Ortiz --- 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) { @@ -610,12 +664,23 @@ 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; } @@ -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;