]> git.kernelconcepts.de Git - karo-tx-linux.git/blobdiff - net/nfc/digital_dep.c
NFC Digital: Add initiator NFC-DEP support
[karo-tx-linux.git] / net / nfc / digital_dep.c
diff --git a/net/nfc/digital_dep.c b/net/nfc/digital_dep.c
new file mode 100644 (file)
index 0000000..be984c4
--- /dev/null
@@ -0,0 +1,381 @@
+/*
+ * NFC Digital Protocol stack
+ * Copyright (c) 2013, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ */
+
+#include "digital.h"
+
+#define DIGITAL_NFC_DEP_FRAME_DIR_OUT 0xD4
+#define DIGITAL_NFC_DEP_FRAME_DIR_IN  0xD5
+
+#define DIGITAL_NFC_DEP_NFCA_SOD_SB   0xF0
+
+#define DIGITAL_CMD_ATR_REQ 0x00
+#define DIGITAL_CMD_ATR_RES 0x01
+#define DIGITAL_CMD_PSL_REQ 0x04
+#define DIGITAL_CMD_PSL_RES 0x05
+#define DIGITAL_CMD_DEP_REQ 0x06
+#define DIGITAL_CMD_DEP_RES 0x07
+
+#define DIGITAL_ATR_REQ_MIN_SIZE 16
+#define DIGITAL_ATR_REQ_MAX_SIZE 64
+
+#define DIGITAL_NFCID3_LEN ((u8)8)
+#define DIGITAL_LR_BITS_PAYLOAD_SIZE_254B 0x30
+#define DIGITAL_GB_BIT 0x02
+
+#define DIGITAL_NFC_DEP_PFB_TYPE(pfb) ((pfb) & 0xE0)
+
+#define DIGITAL_NFC_DEP_PFB_TIMEOUT_BIT 0x10
+
+#define DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb) \
+                               ((pfb) & DIGITAL_NFC_DEP_PFB_TIMEOUT_BIT)
+#define DIGITAL_NFC_DEP_MI_BIT_SET(pfb)  ((pfb) & 0x10)
+#define DIGITAL_NFC_DEP_NAD_BIT_SET(pfb) ((pfb) & 0x08)
+#define DIGITAL_NFC_DEP_DID_BIT_SET(pfb) ((pfb) & 0x04)
+#define DIGITAL_NFC_DEP_PFB_PNI(pfb)     ((pfb) & 0x03)
+
+#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
+
+struct digital_atr_req {
+       u8 dir;
+       u8 cmd;
+       u8 nfcid3[10];
+       u8 did;
+       u8 bs;
+       u8 br;
+       u8 pp;
+       u8 gb[0];
+} __packed;
+
+struct digital_atr_res {
+       u8 dir;
+       u8 cmd;
+       u8 nfcid3[10];
+       u8 did;
+       u8 bs;
+       u8 br;
+       u8 to;
+       u8 pp;
+       u8 gb[0];
+} __packed;
+
+struct digital_psl_req {
+       u8 dir;
+       u8 cmd;
+       u8 did;
+       u8 brs;
+       u8 fsl;
+} __packed;
+
+struct digital_psl_res {
+       u8 dir;
+       u8 cmd;
+       u8 did;
+} __packed;
+
+struct digital_dep_req_res {
+       u8 dir;
+       u8 cmd;
+       u8 pfb;
+} __packed;
+
+static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
+                                   struct sk_buff *resp);
+
+static void digital_skb_push_dep_sod(struct nfc_digital_dev *ddev,
+                                    struct sk_buff *skb)
+{
+       skb_push(skb, sizeof(u8));
+
+       skb->data[0] = skb->len;
+
+       if (ddev->curr_rf_tech == NFC_DIGITAL_RF_TECH_106A)
+               *skb_push(skb, sizeof(u8)) = DIGITAL_NFC_DEP_NFCA_SOD_SB;
+}
+
+static int digital_skb_pull_dep_sod(struct nfc_digital_dev *ddev,
+                                   struct sk_buff *skb)
+{
+       u8 size;
+
+       if (skb->len < 2)
+               return -EIO;
+
+       if (ddev->curr_rf_tech == NFC_DIGITAL_RF_TECH_106A)
+               skb_pull(skb, sizeof(u8));
+
+       size = skb->data[0];
+       if (size != skb->len)
+               return -EIO;
+
+       skb_pull(skb, sizeof(u8));
+
+       return 0;
+}
+
+static void digital_in_recv_atr_res(struct nfc_digital_dev *ddev, void *arg,
+                                struct sk_buff *resp)
+{
+       struct nfc_target *target = arg;
+       struct digital_atr_res *atr_res;
+       u8 gb_len;
+       int rc;
+
+       if (IS_ERR(resp)) {
+               rc = PTR_ERR(resp);
+               resp = NULL;
+               goto exit;
+       }
+
+       rc = ddev->skb_check_crc(resp);
+       if (rc) {
+               PROTOCOL_ERR("14.4.1.6");
+               goto exit;
+       }
+
+       rc = digital_skb_pull_dep_sod(ddev, resp);
+       if (rc) {
+               PROTOCOL_ERR("14.4.1.2");
+               goto exit;
+       }
+
+       if (resp->len < sizeof(struct digital_atr_res)) {
+               rc = -EIO;
+               goto exit;
+       }
+
+       gb_len = resp->len - sizeof(struct digital_atr_res);
+
+       atr_res = (struct digital_atr_res *)resp->data;
+
+       rc = nfc_set_remote_general_bytes(ddev->nfc_dev, atr_res->gb, gb_len);
+       if (rc)
+               goto exit;
+
+       rc = nfc_dep_link_is_up(ddev->nfc_dev, target->idx, NFC_COMM_ACTIVE,
+                               NFC_RF_INITIATOR);
+
+       ddev->curr_nfc_dep_pni = 0;
+
+exit:
+       dev_kfree_skb(resp);
+
+       if (rc)
+               ddev->curr_protocol = 0;
+}
+
+int digital_in_send_atr_req(struct nfc_digital_dev *ddev,
+                           struct nfc_target *target, __u8 comm_mode, __u8 *gb,
+                           size_t gb_len)
+{
+       struct sk_buff *skb;
+       struct digital_atr_req *atr_req;
+       uint size;
+
+       size = DIGITAL_ATR_REQ_MIN_SIZE + gb_len;
+
+       if (size > DIGITAL_ATR_REQ_MAX_SIZE) {
+               PROTOCOL_ERR("14.6.1.1");
+               return -EINVAL;
+       }
+
+       skb = digital_skb_alloc(ddev, size);
+       if (!skb)
+               return -ENOMEM;
+
+       skb_put(skb, sizeof(struct digital_atr_req));
+
+       atr_req = (struct digital_atr_req *)skb->data;
+       memset(atr_req, 0, sizeof(struct digital_atr_req));
+
+       atr_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT;
+       atr_req->cmd = DIGITAL_CMD_ATR_REQ;
+       if (target->nfcid2_len)
+               memcpy(atr_req->nfcid3, target->nfcid2,
+                      max(target->nfcid2_len, DIGITAL_NFCID3_LEN));
+       else
+               get_random_bytes(atr_req->nfcid3, DIGITAL_NFCID3_LEN);
+
+       atr_req->did = 0;
+       atr_req->bs = 0;
+       atr_req->br = 0;
+
+       atr_req->pp = DIGITAL_LR_BITS_PAYLOAD_SIZE_254B;
+
+       if (gb_len) {
+               atr_req->pp |= DIGITAL_GB_BIT;
+               memcpy(skb_put(skb, gb_len), gb, gb_len);
+       }
+
+       digital_skb_push_dep_sod(ddev, skb);
+
+       ddev->skb_add_crc(skb);
+
+       digital_in_send_cmd(ddev, skb, 500, digital_in_recv_atr_res, target);
+
+       return 0;
+}
+
+static int digital_in_send_rtox(struct nfc_digital_dev *ddev,
+                               struct digital_data_exch *data_exch, u8 rtox)
+{
+       struct digital_dep_req_res *dep_req;
+       struct sk_buff *skb;
+       int rc;
+
+       skb = digital_skb_alloc(ddev, 1);
+       if (!skb)
+               return -ENOMEM;
+
+       *skb_put(skb, 1) = rtox;
+
+       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_NFC_DEP_PFB_TIMEOUT_BIT;
+
+       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);
+
+       return rc;
+}
+
+static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
+                                   struct sk_buff *resp)
+{
+       struct digital_data_exch *data_exch = arg;
+       struct digital_dep_req_res *dep_res;
+       u8 pfb;
+       uint size;
+       int rc;
+
+       if (IS_ERR(resp)) {
+               rc = PTR_ERR(resp);
+               resp = NULL;
+               goto exit;
+       }
+
+       rc = ddev->skb_check_crc(resp);
+       if (rc) {
+               PROTOCOL_ERR("14.4.1.6");
+               goto error;
+       }
+
+       rc = digital_skb_pull_dep_sod(ddev, resp);
+       if (rc) {
+               PROTOCOL_ERR("14.4.1.2");
+               goto exit;
+       }
+
+       dep_res = (struct digital_dep_req_res *)resp->data;
+
+       if (resp->len < sizeof(struct digital_dep_req_res) ||
+           dep_res->dir != DIGITAL_NFC_DEP_FRAME_DIR_IN ||
+           dep_res->cmd != DIGITAL_CMD_DEP_RES) {
+               rc = -EIO;
+               goto error;
+       }
+
+       pfb = dep_res->pfb;
+
+       switch (DIGITAL_NFC_DEP_PFB_TYPE(pfb)) {
+       case DIGITAL_NFC_DEP_PFB_I_PDU:
+               if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) {
+                       PROTOCOL_ERR("14.12.3.3");
+                       rc = -EIO;
+                       goto error;
+               }
+
+               ddev->curr_nfc_dep_pni =
+                       DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1);
+               rc = 0;
+               break;
+
+       case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU:
+               PR_ERR("Received a ACK/NACK PDU");
+               rc = -EIO;
+               goto error;
+
+       case DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU:
+               if (!DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb)) {
+                       rc = -EINVAL;
+                       goto error;
+               }
+
+               rc = digital_in_send_rtox(ddev, data_exch, resp->data[3]);
+               if (rc)
+                       goto error;
+
+               kfree_skb(resp);
+               return;
+       }
+
+       if (DIGITAL_NFC_DEP_MI_BIT_SET(pfb)) {
+               PR_ERR("MI bit set. Chained PDU not supported.");
+               rc = -EIO;
+               goto error;
+       }
+
+       size = sizeof(struct digital_dep_req_res);
+
+       if (DIGITAL_NFC_DEP_DID_BIT_SET(pfb))
+               size++;
+
+       if (size > resp->len) {
+               rc = -EIO;
+               goto error;
+       }
+
+       skb_pull(resp, size);
+
+exit:
+       data_exch->cb(data_exch->cb_context, resp, rc);
+
+error:
+       kfree(data_exch);
+
+       if (rc)
+               kfree_skb(resp);
+}
+
+int digital_in_send_dep_req(struct nfc_digital_dev *ddev,
+                           struct nfc_target *target, struct sk_buff *skb,
+                           struct digital_data_exch *data_exch)
+{
+       struct digital_dep_req_res *dep_req;
+
+       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 = ddev->curr_nfc_dep_pni;
+
+       digital_skb_push_dep_sod(ddev, skb);
+
+       ddev->skb_add_crc(skb);
+
+       return digital_in_send_cmd(ddev, skb, 1500, digital_in_recv_dep_res,
+                                  data_exch);
+}