NFC: Set and get DEP general bytes

Without an API for setting and getting the local and remote general bytes,
drivers won't be able to properly establish a DEP link.
This API also allows them to propagate the remote general bytes they get
from the DEP link establishment up to the LLCP layer.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 29 insertions, 1 deletions

diff --git a/drivers/nfc/pn533.c b/drivers/nfc/pn533.c
index ea1caaeed13c..dccd96552f5d 100644
--- a/drivers/nfc/pn533.c
+++ b/drivers/nfc/pn533.c
@@ -1121,6 +1121,7 @@ static int pn533_activate_target_nfcdep(struct pn533 *dev)
 {
         struct pn533_cmd_activate_param param;
         struct pn533_cmd_activate_response *resp;
+        u16 gt_len;
         int rc;
 
         nfc_dev_dbg(&dev->interface->dev, "%s", __func__);
@@ -1146,7 +1147,11 @@ static int pn533_activate_target_nfcdep(struct pn533 *dev)
         if (rc != PN533_CMD_RET_SUCCESS)
                 return -EIO;
 
-        return 0;
+        /* ATR_RES general bytes are located at offset 16 */
+        gt_len = PN533_FRAME_CMD_PARAMS_LEN(dev->in_frame) - 16;
+        rc = nfc_set_remote_general_bytes(dev->nfc_dev, resp->gt, gt_len);
+
+        return rc;
 }
 
 static int pn533_activate_target(struct nfc_dev *nfc_dev, u32 target_idx,
diff --git a/include/net/nfc/nfc.h b/include/net/nfc/nfc.h
index bf82d292d68c..ccfe757a94ec 100644
--- a/include/net/nfc/nfc.h
+++ b/include/net/nfc/nfc.h
@@ -170,6 +170,11 @@ struct sk_buff *nfc_alloc_send_skb(struct nfc_dev *dev, struct sock *sk,
                                         unsigned int *err);
 struct sk_buff *nfc_alloc_recv_skb(unsigned int size, gfp_t gfp);
 
+int nfc_set_remote_general_bytes(struct nfc_dev *dev,
+                                        u8 *gt, u8 gt_len);
+
+u8 *nfc_get_local_general_bytes(struct nfc_dev *dev, u8 *gt_len);
+
 int nfc_targets_found(struct nfc_dev *dev, struct nfc_target *targets,
                                                         int ntargets);
 
diff --git a/net/nfc/core.c b/net/nfc/core.c
index 785f1f20c7ba..3a45f21b3b97 100644
--- a/net/nfc/core.c
+++ b/net/nfc/core.c
@@ -352,6 +352,24 @@ error:
         return rc;
 }
 
+int nfc_set_remote_general_bytes(struct nfc_dev *dev, u8 *gb, u8 gb_len)
+{
+        pr_debug("dev_name=%s gb_len=%d\n",
+                        dev_name(&dev->dev), gb_len);
+
+        if (gb_len > NFC_MAX_GT_LEN)
+                return -EINVAL;
+
+        return 0;
+}
+EXPORT_SYMBOL(nfc_set_remote_general_bytes);
+
+u8 *nfc_get_local_general_bytes(struct nfc_dev *dev, u8 *gt_len)
+{
+        return NULL;
+}
+EXPORT_SYMBOL(nfc_get_local_general_bytes);
+
 /**
  * nfc_alloc_send_skb - allocate a skb for data exchange responses
  *