NFC: digital: Add ISO-DEP support for data exchange
When a type 4A target is activated, this change adds the ISO-DEP SoD
when sending frames and removes it when receiving responses. Chaining
is not supported so sent frames are rejected if they exceed remote FSC
bytes.
Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/net/nfc/digital_technology.c b/net/nfc/digital_technology.c
index 6649d94..278c3fe 100644
--- a/net/nfc/digital_technology.c
+++ b/net/nfc/digital_technology.c
@@ -61,6 +61,15 @@
#define DIGITAL_ISO15693_RES_IS_VALID(flags) \
(!((flags) & DIGITAL_ISO15693_RES_FLAG_ERROR))
+#define DIGITAL_ISO_DEP_I_PCB 0x02
+#define DIGITAL_ISO_DEP_PNI(pni) ((pni) & 0x01)
+
+#define DIGITAL_ISO_DEP_PCB_TYPE(pcb) ((pcb) & 0xC0)
+
+#define DIGITAL_ISO_DEP_I_BLOCK 0x00
+
+#define DIGITAL_ISO_DEP_BLOCK_HAS_DID(pcb) ((pcb) & 0x08)
+
static const u8 digital_ats_fsc[] = {
16, 24, 32, 40, 48, 64, 96, 128,
};
@@ -118,6 +127,54 @@
static int digital_in_send_sdd_req(struct nfc_digital_dev *ddev,
struct nfc_target *target);
+int digital_in_iso_dep_pull_sod(struct nfc_digital_dev *ddev,
+ struct sk_buff *skb)
+{
+ u8 pcb;
+ u8 block_type;
+
+ if (skb->len < 1)
+ return -EIO;
+
+ pcb = *skb->data;
+ block_type = DIGITAL_ISO_DEP_PCB_TYPE(pcb);
+
+ /* No support fo R-block nor S-block */
+ if (block_type != DIGITAL_ISO_DEP_I_BLOCK) {
+ pr_err("ISO_DEP R-block and S-block not supported\n");
+ return -EIO;
+ }
+
+ if (DIGITAL_ISO_DEP_BLOCK_HAS_DID(pcb)) {
+ pr_err("DID field in ISO_DEP PCB not supported\n");
+ return -EIO;
+ }
+
+ skb_pull(skb, 1);
+
+ return 0;
+}
+
+int digital_in_iso_dep_push_sod(struct nfc_digital_dev *ddev,
+ struct sk_buff *skb)
+{
+ /*
+ * Chaining not supported so skb->len + 1 PCB byte + 2 CRC bytes must
+ * not be greater than remote FSC
+ */
+ if (skb->len + 3 > ddev->target_fsc)
+ return -EIO;
+
+ skb_push(skb, 1);
+
+ *skb->data = DIGITAL_ISO_DEP_I_PCB | ddev->curr_nfc_dep_pni;
+
+ ddev->curr_nfc_dep_pni =
+ DIGITAL_ISO_DEP_PNI(ddev->curr_nfc_dep_pni + 1);
+
+ return 0;
+}
+
static void digital_in_recv_ats(struct nfc_digital_dev *ddev, void *arg,
struct sk_buff *resp)
{