NFC: pn533: Send ATR_REQ directly for active device detection

In order to improve active devices detection, we send an ATR_REQ between
each passive detection cycle. Without this algorithm, Android 4.3 based
devices running the Broadcom stack are hardly detected.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

diff --git a/drivers/nfc/pn533.c b/drivers/nfc/pn533.c
index dc744eabeec14bad37c64165368519ef44ef6785..8cffd73690b8d499aef65a3aa1baed48b33d8416 100644 (file)
--- a/drivers/nfc/pn533.c
+++ b/drivers/nfc/pn533.c
@@ -387,6 +387,7 @@ struct pn533 {
        struct pn533_poll_modulations *poll_mod_active[PN533_POLL_MOD_MAX + 1];
        u8 poll_mod_count;
        u8 poll_mod_curr;
+       u8 poll_dep;
        u32 poll_protocols;
        u32 listen_protocols;
        struct timer_list listen_timer;
@@ -1546,6 +1547,9 @@ static int pn533_start_poll_complete(struct pn533 *dev, struct sk_buff *resp)
        u8 nbtg, tg, *tgdata;
        int rc, tgdata_len;
 
+       /* Toggle the DEP polling */
+       dev->poll_dep = 1;
+
        nbtg = resp->data[0];
        tg = resp->data[1];
        tgdata = &resp->data[2];
@@ -1767,6 +1771,117 @@ static void pn533_wq_rf(struct work_struct *work)
        return;
 }
 
+static int pn533_poll_dep_complete(struct pn533 *dev, void *arg,
+                                  struct sk_buff *resp)
+{
+       struct pn533_cmd_jump_dep_response *rsp;
+       struct nfc_target nfc_target;
+       u8 target_gt_len;
+       int rc;
+
+       if (IS_ERR(resp))
+               return PTR_ERR(resp);
+
+       rsp = (struct pn533_cmd_jump_dep_response *)resp->data;
+
+       rc = rsp->status & PN533_CMD_RET_MASK;
+       if (rc != PN533_CMD_RET_SUCCESS) {
+               /* Not target found, turn radio off */
+               queue_work(dev->wq, &dev->rf_work);
+
+               dev_kfree_skb(resp);
+               return 0;
+       }
+
+       dev_dbg(&dev->interface->dev, "Creating new target");
+
+       nfc_target.supported_protocols = NFC_PROTO_NFC_DEP_MASK;
+       nfc_target.nfcid1_len = 10;
+       memcpy(nfc_target.nfcid1, rsp->nfcid3t, nfc_target.nfcid1_len);
+       rc = nfc_targets_found(dev->nfc_dev, &nfc_target, 1);
+       if (rc)
+               goto error;
+
+       dev->tgt_available_prots = 0;
+       dev->tgt_active_prot = NFC_PROTO_NFC_DEP;
+
+       /* ATR_RES general bytes are located at offset 17 */
+       target_gt_len = resp->len - 17;
+       rc = nfc_set_remote_general_bytes(dev->nfc_dev,
+                                         rsp->gt, target_gt_len);
+       if (!rc) {
+               rc = nfc_dep_link_is_up(dev->nfc_dev,
+                                       dev->nfc_dev->targets[0].idx,
+                                       0, NFC_RF_INITIATOR);
+
+               if (!rc)
+                       pn533_poll_reset_mod_list(dev);
+       }
+error:
+       dev_kfree_skb(resp);
+       return rc;
+}
+
+#define PASSIVE_DATA_LEN 5
+static int pn533_poll_dep(struct nfc_dev *nfc_dev)
+{
+       struct pn533 *dev = nfc_get_drvdata(nfc_dev);
+       struct sk_buff *skb;
+       int rc, skb_len;
+       u8 *next, nfcid3[NFC_NFCID3_MAXSIZE];
+       u8 passive_data[PASSIVE_DATA_LEN] = {0x00, 0xff, 0xff, 0x00, 0x3};
+
+       dev_dbg(&dev->interface->dev, "%s", __func__);
+
+       if (!dev->gb) {
+               dev->gb = nfc_get_local_general_bytes(nfc_dev, &dev->gb_len);
+
+               if (!dev->gb || !dev->gb_len) {
+                       dev->poll_dep = 0;
+                       queue_work(dev->wq, &dev->rf_work);
+               }
+       }
+
+       skb_len = 3 + dev->gb_len; /* ActPass + BR + Next */
+       skb_len += PASSIVE_DATA_LEN;
+
+       /* NFCID3 */
+       skb_len += NFC_NFCID3_MAXSIZE;
+       nfcid3[0] = 0x1;
+       nfcid3[1] = 0xfe;
+       get_random_bytes(nfcid3 + 2, 6);
+
+       skb = pn533_alloc_skb(dev, skb_len);
+       if (!skb)
+               return -ENOMEM;
+
+       *skb_put(skb, 1) = 0x01;  /* Active */
+       *skb_put(skb, 1) = 0x02;  /* 424 kbps */
+
+       next = skb_put(skb, 1);  /* Next */
+       *next = 0;
+
+       /* Copy passive data */
+       memcpy(skb_put(skb, PASSIVE_DATA_LEN), passive_data, PASSIVE_DATA_LEN);
+       *next |= 1;
+
+       /* Copy NFCID3 (which is NFCID2 from SENSF_RES) */
+       memcpy(skb_put(skb, NFC_NFCID3_MAXSIZE), nfcid3,
+              NFC_NFCID3_MAXSIZE);
+       *next |= 2;
+
+       memcpy(skb_put(skb, dev->gb_len), dev->gb, dev->gb_len);
+       *next |= 4; /* We have some Gi */
+
+       rc = pn533_send_cmd_async(dev, PN533_CMD_IN_JUMP_FOR_DEP, skb,
+                                 pn533_poll_dep_complete, NULL);
+
+       if (rc < 0)
+               dev_kfree_skb(skb);
+
+       return rc;
+}
+
 static int pn533_poll_complete(struct pn533 *dev, void *arg,
                               struct sk_buff *resp)
 {
@@ -1853,6 +1968,11 @@ static int pn533_send_poll_frame(struct pn533 *dev)
        dev_dbg(&dev->interface->dev, "%s mod len %d\n",
                __func__, mod->len);
 
+       if (dev->poll_dep)  {
+               dev->poll_dep = 0;
+               return pn533_poll_dep(dev->nfc_dev);
+       }
+
        if (mod->len == 0) {  /* Listen mode */
                cmd_code = PN533_CMD_TG_INIT_AS_TARGET;
                skb = pn533_alloc_poll_tg_frame(dev);
@@ -2146,7 +2266,6 @@ error:
 }
 
 static int pn533_rf_field(struct nfc_dev *nfc_dev, u8 rf);
-#define PASSIVE_DATA_LEN 5
 static int pn533_dep_link_up(struct nfc_dev *nfc_dev, struct nfc_target *target,
                             u8 comm_mode, u8 *gb, size_t gb_len)
 {