Merge tag 'hwlock-v4.8' of git://github.com/andersson/remoteproc
[cascardo/linux.git] / net / nfc / digital_dep.c
index f72be74..f864ce1 100644 (file)
@@ -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
@@ -63,6 +65,9 @@
 #define DIGITAL_NFC_DEP_DID_BIT_SET(pfb) ((pfb) & DIGITAL_NFC_DEP_PFB_DID_BIT)
 #define DIGITAL_NFC_DEP_PFB_PNI(pfb)     ((pfb) & 0x03)
 
+#define DIGITAL_NFC_DEP_RTOX_VALUE(data) ((data) & 0x3F)
+#define DIGITAL_NFC_DEP_RTOX_MAX        59
+
 #define DIGITAL_NFC_DEP_PFB_I_PDU          0x00
 #define DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU   0x40
 #define DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU 0x80
@@ -122,6 +127,37 @@ 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))
@@ -190,8 +226,6 @@ digital_send_dep_data_prep(struct nfc_digital_dev *ddev, struct sk_buff *skb,
                        return ERR_PTR(-ENOMEM);
                }
 
-               skb_reserve(new_skb, ddev->tx_headroom + NFC_HEADER_SIZE +
-                                       DIGITAL_NFC_DEP_REQ_RES_HEADROOM);
                memcpy(skb_put(new_skb, ddev->remote_payload_max), skb->data,
                       ddev->remote_payload_max);
                skb_pull(skb, ddev->remote_payload_max);
@@ -368,8 +402,8 @@ 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);
 
@@ -382,6 +416,7 @@ 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)) {
@@ -411,6 +446,11 @@ 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);
 
@@ -492,8 +532,8 @@ 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);
 
@@ -524,11 +564,10 @@ 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;
+       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);
@@ -562,8 +601,8 @@ 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);
 
@@ -593,8 +632,8 @@ 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);
 
@@ -607,6 +646,11 @@ static int digital_in_send_rtox(struct nfc_digital_dev *ddev,
        struct digital_dep_req_res *dep_req;
        struct sk_buff *skb;
        int rc;
+       u16 rwt_int;
+
+       rwt_int = ddev->dep_rwt * rtox;
+       if (rwt_int > digital_rwt_map[DIGITAL_NFC_DEP_IN_MAX_WT])
+               rwt_int = digital_rwt_map[DIGITAL_NFC_DEP_IN_MAX_WT];
 
        skb = digital_skb_alloc(ddev, 1);
        if (!skb)
@@ -627,16 +671,10 @@ 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) {
+       rc = digital_in_send_cmd(ddev, skb, rwt_int,
+                                digital_in_recv_dep_res, data_exch);
+       if (rc)
                kfree_skb(skb);
-               kfree_skb(ddev->saved_skb);
-               ddev->saved_skb = NULL;
-       }
 
        return rc;
 }
@@ -644,11 +682,19 @@ static int digital_in_send_rtox(struct nfc_digital_dev *ddev,
 static int digital_in_send_saved_skb(struct nfc_digital_dev *ddev,
                                     struct digital_data_exch *data_exch)
 {
+       int rc;
+
+       if (!ddev->saved_skb)
+               return -EINVAL;
+
        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);
+       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);
+
+       return rc;
 }
 
 static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
@@ -659,12 +705,13 @@ static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
        u8 pfb;
        uint size;
        int rc;
+       u8 rtox;
 
        if (IS_ERR(resp)) {
                rc = PTR_ERR(resp);
                resp = NULL;
 
-               if (((rc != -ETIMEDOUT) || ddev->nack_count) &&
+               if ((rc == -EIO || (rc == -ETIMEDOUT && ddev->nack_count)) &&
                    (ddev->nack_count++ < DIGITAL_NFC_DEP_N_RETRY_NACK)) {
                        ddev->atn_count = 0;
 
@@ -783,6 +830,12 @@ static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
                break;
 
        case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU:
+               if (DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) {
+                       PROTOCOL_ERR("14.12.4.5");
+                       rc = -EIO;
+                       goto exit;
+               }
+
                if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) {
                        PROTOCOL_ERR("14.12.3.3");
                        rc = -EIO;
@@ -792,43 +845,53 @@ 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);
 
-               if (ddev->chaining_skb && !DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) {
-                       kfree_skb(ddev->saved_skb);
-                       ddev->saved_skb = NULL;
+               if (!ddev->chaining_skb) {
+                       PROTOCOL_ERR("14.12.4.3");
+                       rc = -EIO;
+                       goto exit;
+               }
 
-                       rc = digital_in_send_dep_req(ddev, NULL,
-                                                    ddev->chaining_skb,
-                                                    ddev->data_exch);
-                       if (rc)
-                               goto error;
+               /* The initiator has received a valid ACK. Free the last sent
+                * PDU and keep on sending chained skb.
+                */
+               kfree_skb(ddev->saved_skb);
+               ddev->saved_skb = NULL;
 
-                       return;
-               }
+               rc = digital_in_send_dep_req(ddev, NULL,
+                                            ddev->chaining_skb,
+                                            ddev->data_exch);
+               if (rc)
+                       goto error;
 
-               pr_err("Received a ACK/NACK PDU\n");
-               rc = -EINVAL;
-               goto exit;
+               goto free_resp;
 
        case DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU:
                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);
+                       if (rc)
                                goto error;
-                       }
 
-                       return;
+                       goto free_resp;
                }
 
-               kfree_skb(ddev->saved_skb);
-               ddev->saved_skb = NULL;
+               if (ddev->atn_count || ddev->nack_count) {
+                       PROTOCOL_ERR("14.12.4.4");
+                       rc = -EIO;
+                       goto error;
+               }
+
+               rtox = DIGITAL_NFC_DEP_RTOX_VALUE(resp->data[0]);
+               if (!rtox || rtox > DIGITAL_NFC_DEP_RTOX_MAX) {
+                       PROTOCOL_ERR("14.8.4.1");
+                       rc = -EIO;
+                       goto error;
+               }
 
-               rc = digital_in_send_rtox(ddev, data_exch, resp->data[0]);
+               rc = digital_in_send_rtox(ddev, data_exch, rtox);
                if (rc)
                        goto error;
 
-               kfree_skb(resp);
-               return;
+               goto free_resp;
        }
 
 exit:
@@ -845,6 +908,11 @@ error:
 
        if (rc)
                kfree_skb(resp);
+
+       return;
+
+free_resp:
+       dev_kfree_skb(resp);
 }
 
 int digital_in_send_dep_req(struct nfc_digital_dev *ddev,
@@ -876,11 +944,10 @@ 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;
+       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);
@@ -956,8 +1023,7 @@ static int digital_tg_send_ack(struct nfc_digital_dev *ddev,
 
        ddev->skb_add_crc(skb);
 
-       ddev->saved_skb = skb_get(skb);
-       ddev->saved_skb_len = skb->len;
+       ddev->saved_skb = pskb_copy(skb, GFP_KERNEL);
 
        rc = digital_tg_send_cmd(ddev, skb, 1500, digital_tg_recv_dep_req,
                                 data_exch);
@@ -1009,11 +1075,19 @@ static int digital_tg_send_atn(struct nfc_digital_dev *ddev)
 
 static int digital_tg_send_saved_skb(struct nfc_digital_dev *ddev)
 {
+       int rc;
+
+       if (!ddev->saved_skb)
+               return -EINVAL;
+
        skb_get(ddev->saved_skb);
-       skb_push(ddev->saved_skb, ddev->saved_skb_len);
 
-       return digital_tg_send_cmd(ddev, ddev->saved_skb, 1500,
-                                  digital_tg_recv_dep_req, NULL);
+       rc = digital_tg_send_cmd(ddev, ddev->saved_skb, 1500,
+                                digital_tg_recv_dep_req, NULL);
+       if (rc)
+               kfree_skb(ddev->saved_skb);
+
+       return rc;
 }
 
 static void digital_tg_recv_dep_req(struct nfc_digital_dev *ddev, void *arg,
@@ -1086,22 +1160,38 @@ static void digital_tg_recv_dep_req(struct nfc_digital_dev *ddev, void *arg,
        case DIGITAL_NFC_DEP_PFB_I_PDU:
                pr_debug("DIGITAL_NFC_DEP_PFB_I_PDU\n");
 
-               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) {
+                       /* The target has received (and replied to) at least one
+                        * ATN DEP_REQ.
+                        */
                        ddev->atn_count = 0;
 
-                       rc = digital_tg_send_saved_skb(ddev);
-                       if (rc)
-                               goto exit;
+                       /* pni of resp PDU equal to the target current pni - 1
+                        * means resp is the previous DEP_REQ PDU received from
+                        * the initiator so the target replies with saved_skb
+                        * which is the previous DEP_RES saved in
+                        * digital_tg_send_dep_res().
+                        */
+                       if (DIGITAL_NFC_DEP_PFB_PNI(pfb) ==
+                         DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni - 1)) {
+                               rc = digital_tg_send_saved_skb(ddev);
+                               if (rc)
+                                       goto exit;
 
-                       return;
+                               goto free_resp;
+                       }
+
+                       /* atn_count > 0 and PDU pni != curr_nfc_dep_pni - 1
+                        * means the target probably did not received the last
+                        * DEP_REQ PDU sent by the initiator. The target
+                        * fallbacks to normal processing then.
+                        */
+               }
+
+               if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) {
+                       PROTOCOL_ERR("14.12.3.4");
+                       rc = -EIO;
+                       goto exit;
                }
 
                kfree_skb(ddev->saved_skb);
@@ -1125,51 +1215,64 @@ static void digital_tg_recv_dep_req(struct nfc_digital_dev *ddev, void *arg,
                rc = 0;
                break;
        case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU:
-               if (!DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) { /* ACK */
-                       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) {
+               if (DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) { /* NACK */
+                       if (DIGITAL_NFC_DEP_PFB_PNI(pfb + 1) !=
+                                               ddev->curr_nfc_dep_pni) {
                                rc = -EIO;
                                goto exit;
                        }
 
-                       if (ddev->atn_count) {
-                               ddev->atn_count = 0;
+                       ddev->atn_count = 0;
 
+                       rc = digital_tg_send_saved_skb(ddev);
+                       if (rc)
+                               goto exit;
+
+                       goto free_resp;
+               }
+
+               /* ACK */
+               if (ddev->atn_count) {
+                       /* The target has previously recevied one or more ATN
+                        * PDUs.
+                        */
+                       ddev->atn_count = 0;
+
+                       /* If the ACK PNI is equal to the target PNI - 1 means
+                        * that the initiator did not receive the previous PDU
+                        * sent by the target so re-send it.
+                        */
+                       if (DIGITAL_NFC_DEP_PFB_PNI(pfb + 1) ==
+                                               ddev->curr_nfc_dep_pni) {
                                rc = digital_tg_send_saved_skb(ddev);
                                if (rc)
                                        goto exit;
 
-                               return;
+                               goto free_resp;
                        }
 
-                       kfree_skb(ddev->saved_skb);
-                       ddev->saved_skb = NULL;
+                       /* Otherwise, the target did not receive the previous
+                        * ACK PDU from the initiator. Fallback to normal
+                        * processing of chained PDU then.
+                        */
+               }
 
-                       rc = digital_tg_send_dep_res(ddev, ddev->chaining_skb);
-                       if (rc)
-                               goto exit;
-               } else { /* NACK */
-                       if ((DIGITAL_NFC_DEP_PFB_PNI(pfb + 1) !=
-                                               ddev->curr_nfc_dep_pni) ||
-                           !ddev->saved_skb) {
-                               rc = -EIO;
-                               goto exit;
-                       }
+               /* Keep on sending chained PDU */
+               if (!ddev->chaining_skb ||
+                   DIGITAL_NFC_DEP_PFB_PNI(pfb) !=
+                                       ddev->curr_nfc_dep_pni) {
+                       rc = -EIO;
+                       goto exit;
+               }
 
-                       ddev->atn_count = 0;
+               kfree_skb(ddev->saved_skb);
+               ddev->saved_skb = NULL;
 
-                       rc = digital_tg_send_saved_skb(ddev);
-                       if (rc) {
-                               kfree_skb(ddev->saved_skb);
-                               goto exit;
-                       }
-               }
+               rc = digital_tg_send_dep_res(ddev, ddev->chaining_skb);
+               if (rc)
+                       goto exit;
 
-               return;
+               goto free_resp;
        case DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU:
                if (DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb)) {
                        rc = -EINVAL;
@@ -1182,8 +1285,7 @@ static void digital_tg_recv_dep_req(struct nfc_digital_dev *ddev, void *arg,
 
                ddev->atn_count++;
 
-               kfree_skb(resp);
-               return;
+               goto free_resp;
        }
 
        rc = nfc_tm_data_received(ddev->nfc_dev, resp);
@@ -1199,6 +1301,11 @@ exit:
 
        if (rc)
                kfree_skb(resp);
+
+       return;
+
+free_resp:
+       dev_kfree_skb(resp);
 }
 
 int digital_tg_send_dep_res(struct nfc_digital_dev *ddev, struct sk_buff *skb)
@@ -1235,8 +1342,7 @@ int digital_tg_send_dep_res(struct nfc_digital_dev *ddev, struct sk_buff *skb)
 
        ddev->skb_add_crc(tmp_skb);
 
-       ddev->saved_skb = skb_get(tmp_skb);
-       ddev->saved_skb_len = tmp_skb->len;
+       ddev->saved_skb = pskb_copy(tmp_skb, GFP_KERNEL);
 
        rc = digital_tg_send_cmd(ddev, tmp_skb, 1500, digital_tg_recv_dep_req,
                                 NULL);
@@ -1420,7 +1526,7 @@ 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);