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Commit 673088fb authored by Samuel Ortiz's avatar Samuel Ortiz
Browse files

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: default avatarSamuel Ortiz <sameo@linux.intel.com>
parent e29a9e2a

drivers/nfc/pn533.c

+120 −1
Original line number Diff line number Diff line
@@ -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 @@ static int pn533_in_dep_link_up_complete(struct pn533 *dev, void *arg, 
}



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)

{