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>

1 files changed, 120 insertions, 1 deletions

diff --git a/drivers/nfc/pn533.c b/drivers/nfc/pn533.c
index dc744eabeec1..8cffd73690b8 100644
--- 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)
 {