[deliverable/linux.git] / net / nfc / digital_technology.c

/*
 * NFC Digital Protocol stack
 * Copyright (c) 2013, Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 */

#define pr_fmt(fmt) "digital: %s: " fmt, __func__

#include "digital.h"

#define DIGITAL_CMD_SENS_REQ    0x26
#define DIGITAL_CMD_ALL_REQ     0x52
#define DIGITAL_CMD_SEL_REQ_CL1 0x93
#define DIGITAL_CMD_SEL_REQ_CL2 0x95
#define DIGITAL_CMD_SEL_REQ_CL3 0x97

#define DIGITAL_SDD_REQ_SEL_PAR 0x20

#define DIGITAL_SDD_RES_CT  0x88
#define DIGITAL_SDD_RES_LEN 5

#define DIGITAL_SEL_RES_NFCID1_COMPLETE(sel_res) (!((sel_res) & 0x04))
#define DIGITAL_SEL_RES_IS_T2T(sel_res) (!((sel_res) & 0x60))
#define DIGITAL_SEL_RES_IS_NFC_DEP(sel_res) ((sel_res) & 0x40)

#define DIGITAL_SENS_RES_IS_T1T(sens_res) (((sens_res) & 0x000C) == 0x000C)
#define DIGITAL_SENS_RES_IS_VALID(sens_res) \
	((!((sens_res) & 0x1F00) && (((sens_res) & 0x000C) == 0x000C)) || \
	(((sens_res) & 0x1F00) && ((sens_res) & 0x000C) != 0x000C))

#define DIGITAL_MIFARE_READ_RES_LEN 16
#define DIGITAL_MIFARE_ACK_RES	0x0A

#define DIGITAL_CMD_SENSF_REQ	0x00
#define DIGITAL_CMD_SENSF_RES	0x01

#define DIGITAL_SENSF_RES_MIN_LENGTH 17
#define DIGITAL_SENSF_RES_RD_AP_B1   0x00
#define DIGITAL_SENSF_RES_RD_AP_B2   0x8F

#define DIGITAL_SENSF_REQ_RC_NONE 0
#define DIGITAL_SENSF_REQ_RC_SC   1
#define DIGITAL_SENSF_REQ_RC_AP   2

struct digital_sdd_res {
	u8 nfcid1[4];
	u8 bcc;
} __packed;

struct digital_sel_req {
	u8 sel_cmd;
	u8 b2;
	u8 nfcid1[4];
	u8 bcc;
} __packed;

struct digital_sensf_req {
	u8 cmd;
	u8 sc1;
	u8 sc2;
	u8 rc;
	u8 tsn;
} __packed;

struct digital_sensf_res {
	u8 cmd;
	u8 nfcid2[8];
	u8 pad0[2];
	u8 pad1[3];
	u8 mrti_check;
	u8 mrti_update;
	u8 pad2;
	u8 rd[2];
} __packed;

static int digital_in_send_sdd_req(struct nfc_digital_dev *ddev,
				   struct nfc_target *target);

static void digital_in_recv_sel_res(struct nfc_digital_dev *ddev, void *arg,
				    struct sk_buff *resp)
{
	struct nfc_target *target = arg;
	int rc;
	u8 sel_res;
	u8 nfc_proto;

	if (IS_ERR(resp)) {
		rc = PTR_ERR(resp);
		resp = NULL;
		goto exit;
	}

	if (!DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
		rc = digital_skb_check_crc_a(resp);
		if (rc) {
			PROTOCOL_ERR("4.4.1.3");
			goto exit;
		}
	}

	if (!resp->len) {
		rc = -EIO;
		goto exit;
	}

	sel_res = resp->data[0];

	if (!DIGITAL_SEL_RES_NFCID1_COMPLETE(sel_res)) {
		rc = digital_in_send_sdd_req(ddev, target);
		if (rc)
			goto exit;

		goto exit_free_skb;
	}

	if (DIGITAL_SEL_RES_IS_T2T(sel_res)) {
		nfc_proto = NFC_PROTO_MIFARE;
	} else if (DIGITAL_SEL_RES_IS_NFC_DEP(sel_res)) {
		nfc_proto = NFC_PROTO_NFC_DEP;
	} else {
		rc = -EOPNOTSUPP;
		goto exit;
	}

	target->sel_res = sel_res;

	rc = digital_target_found(ddev, target, nfc_proto);

exit:
	kfree(target);

exit_free_skb:
	dev_kfree_skb(resp);

	if (rc)
		digital_poll_next_tech(ddev);
}

static int digital_in_send_sel_req(struct nfc_digital_dev *ddev,
				   struct nfc_target *target,
				   struct digital_sdd_res *sdd_res)
{
	struct sk_buff *skb;
	struct digital_sel_req *sel_req;
	u8 sel_cmd;
	int rc;

	skb = digital_skb_alloc(ddev, sizeof(struct digital_sel_req));
	if (!skb)
		return -ENOMEM;

	skb_put(skb, sizeof(struct digital_sel_req));
	sel_req = (struct digital_sel_req *)skb->data;

	if (target->nfcid1_len <= 4)
		sel_cmd = DIGITAL_CMD_SEL_REQ_CL1;
	else if (target->nfcid1_len < 10)
		sel_cmd = DIGITAL_CMD_SEL_REQ_CL2;
	else
		sel_cmd = DIGITAL_CMD_SEL_REQ_CL3;

	sel_req->sel_cmd = sel_cmd;
	sel_req->b2 = 0x70;
	memcpy(sel_req->nfcid1, sdd_res->nfcid1, 4);
	sel_req->bcc = sdd_res->bcc;

	if (DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
		rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
				NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A);
		if (rc)
			goto exit;
	} else {
		digital_skb_add_crc_a(skb);
	}

	rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sel_res,
				 target);
exit:
	if (rc)
		kfree_skb(skb);

	return rc;
}

static void digital_in_recv_sdd_res(struct nfc_digital_dev *ddev, void *arg,
				    struct sk_buff *resp)
{
	struct nfc_target *target = arg;
	struct digital_sdd_res *sdd_res;
	int rc;
	u8 offset, size;
	u8 i, bcc;

	if (IS_ERR(resp)) {
		rc = PTR_ERR(resp);
		resp = NULL;
		goto exit;
	}

	if (resp->len < DIGITAL_SDD_RES_LEN) {
		PROTOCOL_ERR("4.7.2.8");
		rc = -EINVAL;
		goto exit;
	}

	sdd_res = (struct digital_sdd_res *)resp->data;

	for (i = 0, bcc = 0; i < 4; i++)
		bcc ^= sdd_res->nfcid1[i];

	if (bcc != sdd_res->bcc) {
		PROTOCOL_ERR("4.7.2.6");
		rc = -EINVAL;
		goto exit;
	}

	if (sdd_res->nfcid1[0] == DIGITAL_SDD_RES_CT) {
		offset = 1;
		size = 3;
	} else {
		offset = 0;
		size = 4;
	}

	memcpy(target->nfcid1 + target->nfcid1_len, sdd_res->nfcid1 + offset,
	       size);
	target->nfcid1_len += size;

	rc = digital_in_send_sel_req(ddev, target, sdd_res);

exit:
	dev_kfree_skb(resp);

	if (rc) {
		kfree(target);
		digital_poll_next_tech(ddev);
	}
}

static int digital_in_send_sdd_req(struct nfc_digital_dev *ddev,
				   struct nfc_target *target)
{
	int rc;
	struct sk_buff *skb;
	u8 sel_cmd;

	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
				     NFC_DIGITAL_FRAMING_NFCA_STANDARD);
	if (rc)
		return rc;

	skb = digital_skb_alloc(ddev, 2);
	if (!skb) {
		pr_err("alloc_skb failed");
		return -ENOMEM;
	}

	if (target->nfcid1_len == 0)
		sel_cmd = DIGITAL_CMD_SEL_REQ_CL1;
	else if (target->nfcid1_len == 3)
		sel_cmd = DIGITAL_CMD_SEL_REQ_CL2;
	else
		sel_cmd = DIGITAL_CMD_SEL_REQ_CL3;

	*skb_put(skb, sizeof(u8)) = sel_cmd;
	*skb_put(skb, sizeof(u8)) = DIGITAL_SDD_REQ_SEL_PAR;

	return digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sdd_res,
				   target);
}

static void digital_in_recv_sens_res(struct nfc_digital_dev *ddev, void *arg,
				     struct sk_buff *resp)
{
	struct nfc_target *target = NULL;
	u16 sens_res;
	int rc;

	if (IS_ERR(resp)) {
		rc = PTR_ERR(resp);
		resp = NULL;
		goto exit;
	}

	if (resp->len < sizeof(u16)) {
		rc = -EIO;
		goto exit;
	}

	target = kzalloc(sizeof(struct nfc_target), GFP_KERNEL);
	if (!target) {
		rc = -ENOMEM;
		goto exit;
	}

	memcpy(&target->sens_res, resp->data, sizeof(u16));

	sens_res = be16_to_cpu(target->sens_res);

	if (!DIGITAL_SENS_RES_IS_VALID(sens_res)) {
		PROTOCOL_ERR("4.6.3.3");
		rc = -EINVAL;
		goto exit;
	}

	if (DIGITAL_SENS_RES_IS_T1T(sens_res))
		rc = digital_target_found(ddev, target, NFC_PROTO_JEWEL);
	else
		rc = digital_in_send_sdd_req(ddev, target);

exit:
	dev_kfree_skb(resp);

	if (rc) {
		kfree(target);
		digital_poll_next_tech(ddev);
	}
}

int digital_in_send_sens_req(struct nfc_digital_dev *ddev, u8 rf_tech)
{
	struct sk_buff *skb;
	int rc;

	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
				     NFC_DIGITAL_RF_TECH_106A);
	if (rc)
		return rc;

	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
				     NFC_DIGITAL_FRAMING_NFCA_SHORT);
	if (rc)
		return rc;

	skb = digital_skb_alloc(ddev, 1);
	if (!skb)
		return -ENOMEM;

	*skb_put(skb, sizeof(u8)) = DIGITAL_CMD_SENS_REQ;

	rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sens_res, NULL);
	if (rc)
		kfree_skb(skb);

	return rc;
}

int digital_in_recv_mifare_res(struct sk_buff *resp)
{
	/* Successful READ command response is 16 data bytes + 2 CRC bytes long.
	 * Since the driver can't differentiate a ACK/NACK response from a valid
	 * READ response, the CRC calculation must be handled at digital level
	 * even if the driver supports it for this technology.
	 */
	if (resp->len == DIGITAL_MIFARE_READ_RES_LEN + DIGITAL_CRC_LEN) {
		if (digital_skb_check_crc_a(resp)) {
			PROTOCOL_ERR("9.4.1.2");
			return -EIO;
		}

		return 0;
	}

	/* ACK response (i.e. successful WRITE). */
	if (resp->len == 1 && resp->data[0] == DIGITAL_MIFARE_ACK_RES) {
		resp->data[0] = 0;
		return 0;
	}

	/* NACK and any other responses are treated as error. */
	return -EIO;
}

static void digital_in_recv_sensf_res(struct nfc_digital_dev *ddev, void *arg,
				   struct sk_buff *resp)
{
	int rc;
	u8 proto;
	struct nfc_target target;
	struct digital_sensf_res *sensf_res;

	if (IS_ERR(resp)) {
		rc = PTR_ERR(resp);
		resp = NULL;
		goto exit;
	}

	if (resp->len < DIGITAL_SENSF_RES_MIN_LENGTH) {
		rc = -EIO;
		goto exit;
	}

	if (!DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
		rc = digital_skb_check_crc_f(resp);
		if (rc) {
			PROTOCOL_ERR("6.4.1.8");
			goto exit;
		}
	}

	skb_pull(resp, 1);

	memset(&target, 0, sizeof(struct nfc_target));

	sensf_res = (struct digital_sensf_res *)resp->data;

	memcpy(target.sensf_res, sensf_res, resp->len);
	target.sensf_res_len = resp->len;

	memcpy(target.nfcid2, sensf_res->nfcid2, NFC_NFCID2_MAXSIZE);
	target.nfcid2_len = NFC_NFCID2_MAXSIZE;

	if (target.nfcid2[0] == DIGITAL_SENSF_NFCID2_NFC_DEP_B1 &&
	    target.nfcid2[1] == DIGITAL_SENSF_NFCID2_NFC_DEP_B2)
		proto = NFC_PROTO_NFC_DEP;
	else
		proto = NFC_PROTO_FELICA;

	rc = digital_target_found(ddev, &target, proto);

exit:
	dev_kfree_skb(resp);

	if (rc)
		digital_poll_next_tech(ddev);
}

int digital_in_send_sensf_req(struct nfc_digital_dev *ddev, u8 rf_tech)
{
	struct digital_sensf_req *sensf_req;
	struct sk_buff *skb;
	int rc;
	u8 size;

	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH, rf_tech);
	if (rc)
		return rc;

	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
				     NFC_DIGITAL_FRAMING_NFCF);
	if (rc)
		return rc;

	size = sizeof(struct digital_sensf_req);

	skb = digital_skb_alloc(ddev, size);
	if (!skb)
		return -ENOMEM;

	skb_put(skb, size);

	sensf_req = (struct digital_sensf_req *)skb->data;
	sensf_req->cmd = DIGITAL_CMD_SENSF_REQ;
	sensf_req->sc1 = 0xFF;
	sensf_req->sc2 = 0xFF;
	sensf_req->rc = 0;
	sensf_req->tsn = 0;

	*skb_push(skb, 1) = size + 1;

	if (!DIGITAL_DRV_CAPS_IN_CRC(ddev))
		digital_skb_add_crc_f(skb);

	rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sensf_res,
				 NULL);
	if (rc)
		kfree_skb(skb);

	return rc;
}

static int digital_tg_send_sel_res(struct nfc_digital_dev *ddev)
{
	struct sk_buff *skb;
	int rc;

	skb = digital_skb_alloc(ddev, 1);
	if (!skb)
		return -ENOMEM;

	*skb_put(skb, 1) = DIGITAL_SEL_RES_NFC_DEP;

	if (!DIGITAL_DRV_CAPS_TG_CRC(ddev))
		digital_skb_add_crc_a(skb);

	rc = digital_tg_send_cmd(ddev, skb, 300, digital_tg_recv_atr_req,
				 NULL);
	if (rc)
		kfree_skb(skb);

	return rc;
}

static void digital_tg_recv_sel_req(struct nfc_digital_dev *ddev, void *arg,
				    struct sk_buff *resp)
{
	int rc;

	if (IS_ERR(resp)) {
		rc = PTR_ERR(resp);
		resp = NULL;
		goto exit;
	}

	if (!DIGITAL_DRV_CAPS_TG_CRC(ddev)) {
		rc = digital_skb_check_crc_a(resp);
		if (rc) {
			PROTOCOL_ERR("4.4.1.3");
			goto exit;
		}
	}

	/* Silently ignore SEL_REQ content and send a SEL_RES for NFC-DEP */

	rc = digital_tg_send_sel_res(ddev);

exit:
	if (rc)
		digital_poll_next_tech(ddev);

	dev_kfree_skb(resp);
}

static int digital_tg_send_sdd_res(struct nfc_digital_dev *ddev)
{
	struct sk_buff *skb;
	struct digital_sdd_res *sdd_res;
	int rc, i;

	skb = digital_skb_alloc(ddev, sizeof(struct digital_sdd_res));
	if (!skb)
		return -ENOMEM;

	skb_put(skb, sizeof(struct digital_sdd_res));
	sdd_res = (struct digital_sdd_res *)skb->data;

	sdd_res->nfcid1[0] = 0x08;
	get_random_bytes(sdd_res->nfcid1 + 1, 3);

	sdd_res->bcc = 0;
	for (i = 0; i < 4; i++)
		sdd_res->bcc ^= sdd_res->nfcid1[i];

	rc = digital_tg_send_cmd(ddev, skb, 300, digital_tg_recv_sel_req,
				 NULL);
	if (rc)
		kfree_skb(skb);

	return rc;
}

static void digital_tg_recv_sdd_req(struct nfc_digital_dev *ddev, void *arg,
				    struct sk_buff *resp)
{
	u8 *sdd_req;
	int rc;

	if (IS_ERR(resp)) {
		rc = PTR_ERR(resp);
		resp = NULL;
		goto exit;
	}

	sdd_req = resp->data;

	if (resp->len < 2 || sdd_req[0] != DIGITAL_CMD_SEL_REQ_CL1 ||
	    sdd_req[1] != DIGITAL_SDD_REQ_SEL_PAR) {
		rc = -EINVAL;
		goto exit;
	}

	rc = digital_tg_send_sdd_res(ddev);

exit:
	if (rc)
		digital_poll_next_tech(ddev);

	dev_kfree_skb(resp);
}

static int digital_tg_send_sens_res(struct nfc_digital_dev *ddev)
{
	struct sk_buff *skb;
	u8 *sens_res;
	int rc;

	skb = digital_skb_alloc(ddev, 2);
	if (!skb)
		return -ENOMEM;

	sens_res = skb_put(skb, 2);

	sens_res[0] = (DIGITAL_SENS_RES_NFC_DEP >> 8) & 0xFF;
	sens_res[1] = DIGITAL_SENS_RES_NFC_DEP & 0xFF;

	rc = digital_tg_send_cmd(ddev, skb, 300, digital_tg_recv_sdd_req,
				 NULL);
	if (rc)
		kfree_skb(skb);

	return rc;
}

void digital_tg_recv_sens_req(struct nfc_digital_dev *ddev, void *arg,
			      struct sk_buff *resp)
{
	u8 sens_req;
	int rc;

	if (IS_ERR(resp)) {
		rc = PTR_ERR(resp);
		resp = NULL;
		goto exit;
	}

	sens_req = resp->data[0];

	if (!resp->len || (sens_req != DIGITAL_CMD_SENS_REQ &&
	    sens_req != DIGITAL_CMD_ALL_REQ)) {
		rc = -EINVAL;
		goto exit;
	}

	rc = digital_tg_send_sens_res(ddev);

exit:
	if (rc)
		digital_poll_next_tech(ddev);

	dev_kfree_skb(resp);
}

int digital_tg_send_sensf_res(struct nfc_digital_dev *ddev,
			      struct digital_sensf_req *sensf_req)
{
	struct sk_buff *skb;
	u8 size;
	int rc;
	struct digital_sensf_res *sensf_res;

	size = sizeof(struct digital_sensf_res);

	if (sensf_req->rc != DIGITAL_SENSF_REQ_RC_NONE)
		size -= sizeof(sensf_res->rd);

	skb = digital_skb_alloc(ddev, size);
	if (!skb)
		return -ENOMEM;

	skb_put(skb, size);

	sensf_res = (struct digital_sensf_res *)skb->data;

	memset(sensf_res, 0, size);

	sensf_res->cmd = DIGITAL_CMD_SENSF_RES;
	sensf_res->nfcid2[0] = DIGITAL_SENSF_NFCID2_NFC_DEP_B1;
	sensf_res->nfcid2[1] = DIGITAL_SENSF_NFCID2_NFC_DEP_B2;
	get_random_bytes(&sensf_res->nfcid2[2], 6);

	switch (sensf_req->rc) {
	case DIGITAL_SENSF_REQ_RC_SC:
		sensf_res->rd[0] = sensf_req->sc1;
		sensf_res->rd[1] = sensf_req->sc2;
		break;
	case DIGITAL_SENSF_REQ_RC_AP:
		sensf_res->rd[0] = DIGITAL_SENSF_RES_RD_AP_B1;
		sensf_res->rd[1] = DIGITAL_SENSF_RES_RD_AP_B2;
		break;
	}

	*skb_push(skb, sizeof(u8)) = size + 1;

	if (!DIGITAL_DRV_CAPS_TG_CRC(ddev))
		digital_skb_add_crc_f(skb);

	rc = digital_tg_send_cmd(ddev, skb, 300,
				 digital_tg_recv_atr_req, NULL);
	if (rc)
		kfree_skb(skb);

	return rc;
}

void digital_tg_recv_sensf_req(struct nfc_digital_dev *ddev, void *arg,
			       struct sk_buff *resp)
{
	struct digital_sensf_req *sensf_req;
	int rc;

	if (IS_ERR(resp)) {
		rc = PTR_ERR(resp);
		resp = NULL;
		goto exit;
	}

	if (!DIGITAL_DRV_CAPS_TG_CRC(ddev)) {
		rc = digital_skb_check_crc_f(resp);
		if (rc) {
			PROTOCOL_ERR("6.4.1.8");
			goto exit;
		}
	}

	if (resp->len != sizeof(struct digital_sensf_req) + 1) {
		rc = -EINVAL;
		goto exit;
	}

	skb_pull(resp, 1);
	sensf_req = (struct digital_sensf_req *)resp->data;

	if (sensf_req->cmd != DIGITAL_CMD_SENSF_REQ) {
		rc = -EINVAL;
		goto exit;
	}

	rc = digital_tg_send_sensf_res(ddev, sensf_req);

exit:
	if (rc)
		digital_poll_next_tech(ddev);

	dev_kfree_skb(resp);
}

int digital_tg_listen_nfca(struct nfc_digital_dev *ddev, u8 rf_tech)
{
	int rc;

	rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH, rf_tech);
	if (rc)
		return rc;

	rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
				     NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
	if (rc)
		return rc;

	return digital_tg_listen(ddev, 300, digital_tg_recv_sens_req, NULL);
}

int digital_tg_listen_nfcf(struct nfc_digital_dev *ddev, u8 rf_tech)
{
	int rc;
	u8 *nfcid2;

	rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH, rf_tech);
	if (rc)
		return rc;

	rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
				     NFC_DIGITAL_FRAMING_NFCF_NFC_DEP);
	if (rc)
		return rc;

	nfcid2 = kzalloc(NFC_NFCID2_MAXSIZE, GFP_KERNEL);
	if (!nfcid2)
		return -ENOMEM;

	nfcid2[0] = DIGITAL_SENSF_NFCID2_NFC_DEP_B1;
	nfcid2[1] = DIGITAL_SENSF_NFCID2_NFC_DEP_B2;
	get_random_bytes(nfcid2 + 2, NFC_NFCID2_MAXSIZE - 2);

	return digital_tg_listen(ddev, 300, digital_tg_recv_sensf_req, nfcid2);
}
Commit	Line	Data
59ee2361 TE	1	/*
	2	* NFC Digital Protocol stack
	3	* Copyright (c) 2013, Intel Corporation.
	4	*
	5	* This program is free software; you can redistribute it and/or modify it
	6	* under the terms and conditions of the GNU General Public License,
	7	* version 2, as published by the Free Software Foundation.
	8	*
	9	* This program is distributed in the hope it will be useful, but WITHOUT
	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	12	* more details.
	13	*
	14	*/
	15
c5da0e4a SO	16	#define pr_fmt(fmt) "digital: %s: " fmt, __func__
c5da0e4a SO	17
59ee2361 TE	18	#include "digital.h"
	19
	20	#define DIGITAL_CMD_SENS_REQ 0x26
	21	#define DIGITAL_CMD_ALL_REQ 0x52
	22	#define DIGITAL_CMD_SEL_REQ_CL1 0x93
	23	#define DIGITAL_CMD_SEL_REQ_CL2 0x95
	24	#define DIGITAL_CMD_SEL_REQ_CL3 0x97
	25
	26	#define DIGITAL_SDD_REQ_SEL_PAR 0x20
	27
	28	#define DIGITAL_SDD_RES_CT 0x88
	29	#define DIGITAL_SDD_RES_LEN 5
	30
2c66daec TE	31	#define DIGITAL_SEL_RES_NFCID1_COMPLETE(sel_res) (!((sel_res) & 0x04))
2c66daec TE	32	#define DIGITAL_SEL_RES_IS_T2T(sel_res) (!((sel_res) & 0x60))
7d0911c0	33	#define DIGITAL_SEL_RES_IS_NFC_DEP(sel_res) ((sel_res) & 0x40)
2c66daec TE	34
	35	#define DIGITAL_SENS_RES_IS_T1T(sens_res) (((sens_res) & 0x000C) == 0x000C)
	36	#define DIGITAL_SENS_RES_IS_VALID(sens_res) \
	37	((!((sens_res) & 0x1F00) && (((sens_res) & 0x000C) == 0x000C)) \|\| \
	38	(((sens_res) & 0x1F00) && ((sens_res) & 0x000C) != 0x000C))
	39
	40	#define DIGITAL_MIFARE_READ_RES_LEN 16
	41	#define DIGITAL_MIFARE_ACK_RES 0x0A
	42
8c0695e4 TE	43	#define DIGITAL_CMD_SENSF_REQ 0x00
	44	#define DIGITAL_CMD_SENSF_RES 0x01
	45
	46	#define DIGITAL_SENSF_RES_MIN_LENGTH 17
	47	#define DIGITAL_SENSF_RES_RD_AP_B1 0x00
	48	#define DIGITAL_SENSF_RES_RD_AP_B2 0x8F
	49
	50	#define DIGITAL_SENSF_REQ_RC_NONE 0
	51	#define DIGITAL_SENSF_REQ_RC_SC 1
	52	#define DIGITAL_SENSF_REQ_RC_AP 2
	53
2c66daec TE	54	struct digital_sdd_res {
	55	u8 nfcid1[4];
	56	u8 bcc;
	57	} __packed;
	58
	59	struct digital_sel_req {
	60	u8 sel_cmd;
	61	u8 b2;
	62	u8 nfcid1[4];
	63	u8 bcc;
	64	} __packed;
	65
8c0695e4 TE	66	struct digital_sensf_req {
	67	u8 cmd;
	68	u8 sc1;
	69	u8 sc2;
	70	u8 rc;
	71	u8 tsn;
	72	} __packed;
	73
	74	struct digital_sensf_res {
	75	u8 cmd;
	76	u8 nfcid2[8];
	77	u8 pad0[2];
	78	u8 pad1[3];
	79	u8 mrti_check;
	80	u8 mrti_update;
	81	u8 pad2;
	82	u8 rd[2];
	83	} __packed;
	84
2c66daec TE	85	static int digital_in_send_sdd_req(struct nfc_digital_dev *ddev,
	86	struct nfc_target *target);
	87
	88	static void digital_in_recv_sel_res(struct nfc_digital_dev ddev, void arg,
	89	struct sk_buff *resp)
	90	{
	91	struct nfc_target *target = arg;
	92	int rc;
	93	u8 sel_res;
	94	u8 nfc_proto;
	95
	96	if (IS_ERR(resp)) {
	97	rc = PTR_ERR(resp);
	98	resp = NULL;
	99	goto exit;
	100	}
	101
	102	if (!DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
	103	rc = digital_skb_check_crc_a(resp);
	104	if (rc) {
	105	PROTOCOL_ERR("4.4.1.3");
	106	goto exit;
	107	}
	108	}
	109
	110	if (!resp->len) {
	111	rc = -EIO;
	112	goto exit;
	113	}
	114
	115	sel_res = resp->data[0];
	116
	117	if (!DIGITAL_SEL_RES_NFCID1_COMPLETE(sel_res)) {
	118	rc = digital_in_send_sdd_req(ddev, target);
	119	if (rc)
	120	goto exit;
	121
	122	goto exit_free_skb;
	123	}
	124
	125	if (DIGITAL_SEL_RES_IS_T2T(sel_res)) {
	126	nfc_proto = NFC_PROTO_MIFARE;
7d0911c0 TE	127	} else if (DIGITAL_SEL_RES_IS_NFC_DEP(sel_res)) {
7d0911c0 TE	128	nfc_proto = NFC_PROTO_NFC_DEP;
2c66daec TE	129	} else {
	130	rc = -EOPNOTSUPP;
	131	goto exit;
	132	}
	133
	134	target->sel_res = sel_res;
	135
	136	rc = digital_target_found(ddev, target, nfc_proto);
	137
	138	exit:
	139	kfree(target);
	140
	141	exit_free_skb:
	142	dev_kfree_skb(resp);
	143
	144	if (rc)
	145	digital_poll_next_tech(ddev);
	146	}
	147
	148	static int digital_in_send_sel_req(struct nfc_digital_dev *ddev,
	149	struct nfc_target *target,
	150	struct digital_sdd_res *sdd_res)
	151	{
	152	struct sk_buff *skb;
	153	struct digital_sel_req *sel_req;
	154	u8 sel_cmd;
	155	int rc;
	156
	157	skb = digital_skb_alloc(ddev, sizeof(struct digital_sel_req));
	158	if (!skb)
	159	return -ENOMEM;
	160
	161	skb_put(skb, sizeof(struct digital_sel_req));
	162	sel_req = (struct digital_sel_req *)skb->data;
	163
	164	if (target->nfcid1_len <= 4)
	165	sel_cmd = DIGITAL_CMD_SEL_REQ_CL1;
	166	else if (target->nfcid1_len < 10)
	167	sel_cmd = DIGITAL_CMD_SEL_REQ_CL2;
	168	else
	169	sel_cmd = DIGITAL_CMD_SEL_REQ_CL3;
	170
	171	sel_req->sel_cmd = sel_cmd;
	172	sel_req->b2 = 0x70;
	173	memcpy(sel_req->nfcid1, sdd_res->nfcid1, 4);
	174	sel_req->bcc = sdd_res->bcc;
	175
	176	if (DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
	177	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
	178	NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A);
	179	if (rc)
	180	goto exit;
	181	} else {
	182	digital_skb_add_crc_a(skb);
	183	}
	184
	185	rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sel_res,
	186	target);
	187	exit:
	188	if (rc)
	189	kfree_skb(skb);
	190
	191	return rc;
	192	}
193
194	static void digital_in_recv_sdd_res(struct nfc_digital_dev ddev, void arg,
195	struct sk_buff *resp)
196	{
197	struct nfc_target *target = arg;
198	struct digital_sdd_res *sdd_res;
199	int rc;
200	u8 offset, size;
201	u8 i, bcc;
202
203	if (IS_ERR(resp)) {
204	rc = PTR_ERR(resp);
205	resp = NULL;
206	goto exit;
207	}
208
209	if (resp->len < DIGITAL_SDD_RES_LEN) {
210	PROTOCOL_ERR("4.7.2.8");
211	rc = -EINVAL;
212	goto exit;
213	}
214
215	sdd_res = (struct digital_sdd_res *)resp->data;
216
217	for (i = 0, bcc = 0; i < 4; i++)
218	bcc ^= sdd_res->nfcid1[i];
219
220	if (bcc != sdd_res->bcc) {
221	PROTOCOL_ERR("4.7.2.6");
222	rc = -EINVAL;
223	goto exit;
224	}
225
226	if (sdd_res->nfcid1[0] == DIGITAL_SDD_RES_CT) {
227	offset = 1;
228	size = 3;
229	} else {
230	offset = 0;
231	size = 4;
232	}
233
234	memcpy(target->nfcid1 + target->nfcid1_len, sdd_res->nfcid1 + offset,
235	size);
236	target->nfcid1_len += size;
237
238	rc = digital_in_send_sel_req(ddev, target, sdd_res);
239
240	exit:
241	dev_kfree_skb(resp);
242
243	if (rc) {
244	kfree(target);
245	digital_poll_next_tech(ddev);
246	}
247	}
248
249	static int digital_in_send_sdd_req(struct nfc_digital_dev *ddev,
250	struct nfc_target *target)
251	{
252	int rc;
253	struct sk_buff *skb;
254	u8 sel_cmd;
255
256	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
257	NFC_DIGITAL_FRAMING_NFCA_STANDARD);
258	if (rc)
259	return rc;
260
261	skb = digital_skb_alloc(ddev, 2);
262	if (!skb) {
c5da0e4a	263	pr_err("alloc_skb failed");
2c66daec TE	264	return -ENOMEM;
	265	}
	266
	267	if (target->nfcid1_len == 0)
	268	sel_cmd = DIGITAL_CMD_SEL_REQ_CL1;
	269	else if (target->nfcid1_len == 3)
	270	sel_cmd = DIGITAL_CMD_SEL_REQ_CL2;
	271	else
	272	sel_cmd = DIGITAL_CMD_SEL_REQ_CL3;
	273
	274	*skb_put(skb, sizeof(u8)) = sel_cmd;
	275	*skb_put(skb, sizeof(u8)) = DIGITAL_SDD_REQ_SEL_PAR;
	276
	277	return digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sdd_res,
	278	target);
	279	}
	280
59ee2361 TE	281	static void digital_in_recv_sens_res(struct nfc_digital_dev ddev, void arg,
	282	struct sk_buff *resp)
	283	{
2c66daec TE	284	struct nfc_target *target = NULL;
	285	u16 sens_res;
	286	int rc;
	287
	288	if (IS_ERR(resp)) {
	289	rc = PTR_ERR(resp);
	290	resp = NULL;
	291	goto exit;
	292	}
	293
	294	if (resp->len < sizeof(u16)) {
	295	rc = -EIO;
	296	goto exit;
	297	}
	298
	299	target = kzalloc(sizeof(struct nfc_target), GFP_KERNEL);
	300	if (!target) {
	301	rc = -ENOMEM;
	302	goto exit;
	303	}
	304
	305	memcpy(&target->sens_res, resp->data, sizeof(u16));
59ee2361	306
2c66daec TE	307	sens_res = be16_to_cpu(target->sens_res);
	308
	309	if (!DIGITAL_SENS_RES_IS_VALID(sens_res)) {
	310	PROTOCOL_ERR("4.6.3.3");
	311	rc = -EINVAL;
	312	goto exit;
	313	}
	314
	315	if (DIGITAL_SENS_RES_IS_T1T(sens_res))
	316	rc = digital_target_found(ddev, target, NFC_PROTO_JEWEL);
	317	else
	318	rc = digital_in_send_sdd_req(ddev, target);
	319
	320	exit:
	321	dev_kfree_skb(resp);
	322
	323	if (rc) {
	324	kfree(target);
	325	digital_poll_next_tech(ddev);
	326	}
59ee2361 TE	327	}
	328
	329	int digital_in_send_sens_req(struct nfc_digital_dev *ddev, u8 rf_tech)
	330	{
	331	struct sk_buff *skb;
	332	int rc;
	333
	334	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
	335	NFC_DIGITAL_RF_TECH_106A);
	336	if (rc)
	337	return rc;
	338
	339	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
	340	NFC_DIGITAL_FRAMING_NFCA_SHORT);
	341	if (rc)
	342	return rc;
	343
	344	skb = digital_skb_alloc(ddev, 1);
	345	if (!skb)
	346	return -ENOMEM;
	347
	348	*skb_put(skb, sizeof(u8)) = DIGITAL_CMD_SENS_REQ;
	349
	350	rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sens_res, NULL);
	351	if (rc)
	352	kfree_skb(skb);
	353
	354	return rc;
	355	}
2c66daec TE	356
	357	int digital_in_recv_mifare_res(struct sk_buff *resp)
	358	{
	359	/* Successful READ command response is 16 data bytes + 2 CRC bytes long.
	360	* Since the driver can't differentiate a ACK/NACK response from a valid
	361	* READ response, the CRC calculation must be handled at digital level
	362	* even if the driver supports it for this technology.
	363	*/
	364	if (resp->len == DIGITAL_MIFARE_READ_RES_LEN + DIGITAL_CRC_LEN) {
	365	if (digital_skb_check_crc_a(resp)) {
	366	PROTOCOL_ERR("9.4.1.2");
	367	return -EIO;
	368	}
	369
	370	return 0;
	371	}
	372
	373	/* ACK response (i.e. successful WRITE). */
	374	if (resp->len == 1 && resp->data[0] == DIGITAL_MIFARE_ACK_RES) {
	375	resp->data[0] = 0;
	376	return 0;
	377	}
	378
	379	/* NACK and any other responses are treated as error. */
	380	return -EIO;
	381	}
8c0695e4 TE	382
	383	static void digital_in_recv_sensf_res(struct nfc_digital_dev ddev, void arg,
	384	struct sk_buff *resp)
	385	{
	386	int rc;
7d0911c0	387	u8 proto;
8c0695e4 TE	388	struct nfc_target target;
	389	struct digital_sensf_res *sensf_res;
	390
	391	if (IS_ERR(resp)) {
	392	rc = PTR_ERR(resp);
	393	resp = NULL;
	394	goto exit;
	395	}
	396
	397	if (resp->len < DIGITAL_SENSF_RES_MIN_LENGTH) {
	398	rc = -EIO;
	399	goto exit;
	400	}
	401
	402	if (!DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
	403	rc = digital_skb_check_crc_f(resp);
	404	if (rc) {
	405	PROTOCOL_ERR("6.4.1.8");
	406	goto exit;
	407	}
	408	}
	409
	410	skb_pull(resp, 1);
	411
	412	memset(&target, 0, sizeof(struct nfc_target));
	413
	414	sensf_res = (struct digital_sensf_res *)resp->data;
	415
	416	memcpy(target.sensf_res, sensf_res, resp->len);
	417	target.sensf_res_len = resp->len;
	418
	419	memcpy(target.nfcid2, sensf_res->nfcid2, NFC_NFCID2_MAXSIZE);
	420	target.nfcid2_len = NFC_NFCID2_MAXSIZE;
	421
7d0911c0 TE	422	if (target.nfcid2[0] == DIGITAL_SENSF_NFCID2_NFC_DEP_B1 &&
	423	target.nfcid2[1] == DIGITAL_SENSF_NFCID2_NFC_DEP_B2)
	424	proto = NFC_PROTO_NFC_DEP;
	425	else
	426	proto = NFC_PROTO_FELICA;
	427
	428	rc = digital_target_found(ddev, &target, proto);
8c0695e4 TE	429
	430	exit:
	431	dev_kfree_skb(resp);
	432
	433	if (rc)
	434	digital_poll_next_tech(ddev);
	435	}
	436
	437	int digital_in_send_sensf_req(struct nfc_digital_dev *ddev, u8 rf_tech)
	438	{
	439	struct digital_sensf_req *sensf_req;
	440	struct sk_buff *skb;
	441	int rc;
	442	u8 size;
	443
	444	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH, rf_tech);
	445	if (rc)
	446	return rc;
	447
	448	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
	449	NFC_DIGITAL_FRAMING_NFCF);
	450	if (rc)
	451	return rc;
	452
	453	size = sizeof(struct digital_sensf_req);
	454
	455	skb = digital_skb_alloc(ddev, size);
	456	if (!skb)
	457	return -ENOMEM;
	458
	459	skb_put(skb, size);
	460
	461	sensf_req = (struct digital_sensf_req *)skb->data;
	462	sensf_req->cmd = DIGITAL_CMD_SENSF_REQ;
	463	sensf_req->sc1 = 0xFF;
	464	sensf_req->sc2 = 0xFF;
	465	sensf_req->rc = 0;
	466	sensf_req->tsn = 0;
	467
	468	*skb_push(skb, 1) = size + 1;
	469
	470	if (!DIGITAL_DRV_CAPS_IN_CRC(ddev))
	471	digital_skb_add_crc_f(skb);
	472
	473	rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sensf_res,
	474	NULL);
	475	if (rc)
	476	kfree_skb(skb);
	477
	478	return rc;
	479	}
1c7a4c24 TE	480
	481	static int digital_tg_send_sel_res(struct nfc_digital_dev *ddev)
	482	{
	483	struct sk_buff *skb;
	484	int rc;
	485
	486	skb = digital_skb_alloc(ddev, 1);
	487	if (!skb)
	488	return -ENOMEM;
	489
	490	*skb_put(skb, 1) = DIGITAL_SEL_RES_NFC_DEP;
	491
	492	if (!DIGITAL_DRV_CAPS_TG_CRC(ddev))
	493	digital_skb_add_crc_a(skb);
	494
	495	rc = digital_tg_send_cmd(ddev, skb, 300, digital_tg_recv_atr_req,
	496	NULL);
	497	if (rc)
	498	kfree_skb(skb);
	499
	500	return rc;
	501	}
	502
	503	static void digital_tg_recv_sel_req(struct nfc_digital_dev ddev, void arg,
	504	struct sk_buff *resp)
	505	{
	506	int rc;
	507
	508	if (IS_ERR(resp)) {
	509	rc = PTR_ERR(resp);
	510	resp = NULL;
	511	goto exit;
	512	}
	513
	514	if (!DIGITAL_DRV_CAPS_TG_CRC(ddev)) {
	515	rc = digital_skb_check_crc_a(resp);
	516	if (rc) {
	517	PROTOCOL_ERR("4.4.1.3");
	518	goto exit;
	519	}
	520	}
	521
	522	/* Silently ignore SEL_REQ content and send a SEL_RES for NFC-DEP */
	523
	524	rc = digital_tg_send_sel_res(ddev);
	525
	526	exit:
	527	if (rc)
	528	digital_poll_next_tech(ddev);
	529
	530	dev_kfree_skb(resp);
	531	}
	532
	533	static int digital_tg_send_sdd_res(struct nfc_digital_dev *ddev)
	534	{
	535	struct sk_buff *skb;
	536	struct digital_sdd_res *sdd_res;
	537	int rc, i;
	538
	539	skb = digital_skb_alloc(ddev, sizeof(struct digital_sdd_res));
	540	if (!skb)
	541	return -ENOMEM;
	542
	543	skb_put(skb, sizeof(struct digital_sdd_res));
544	sdd_res = (struct digital_sdd_res *)skb->data;
545
546	sdd_res->nfcid1[0] = 0x08;
547	get_random_bytes(sdd_res->nfcid1 + 1, 3);
548
549	sdd_res->bcc = 0;
550	for (i = 0; i < 4; i++)
551	sdd_res->bcc ^= sdd_res->nfcid1[i];
552
553	rc = digital_tg_send_cmd(ddev, skb, 300, digital_tg_recv_sel_req,
554	NULL);
555	if (rc)
556	kfree_skb(skb);
557
558	return rc;
559	}
560
561	static void digital_tg_recv_sdd_req(struct nfc_digital_dev ddev, void arg,
562	struct sk_buff *resp)
563	{
564	u8 *sdd_req;
565	int rc;
566
567	if (IS_ERR(resp)) {
568	rc = PTR_ERR(resp);
569	resp = NULL;
570	goto exit;
571	}
572
573	sdd_req = resp->data;
574
575	if (resp->len < 2 \|\| sdd_req[0] != DIGITAL_CMD_SEL_REQ_CL1 \|\|
576	sdd_req[1] != DIGITAL_SDD_REQ_SEL_PAR) {
577	rc = -EINVAL;
578	goto exit;
579	}
580
581	rc = digital_tg_send_sdd_res(ddev);
582
583	exit:
584	if (rc)
585	digital_poll_next_tech(ddev);
586
587	dev_kfree_skb(resp);
588	}
589
590	static int digital_tg_send_sens_res(struct nfc_digital_dev *ddev)
591	{
592	struct sk_buff *skb;
593	u8 *sens_res;
594	int rc;
595
596	skb = digital_skb_alloc(ddev, 2);
597	if (!skb)
598	return -ENOMEM;
599
600	sens_res = skb_put(skb, 2);
601
602	sens_res[0] = (DIGITAL_SENS_RES_NFC_DEP >> 8) & 0xFF;
603	sens_res[1] = DIGITAL_SENS_RES_NFC_DEP & 0xFF;
604
605	rc = digital_tg_send_cmd(ddev, skb, 300, digital_tg_recv_sdd_req,
606	NULL);
607	if (rc)
608	kfree_skb(skb);
609
610	return rc;
611	}
612
613	void digital_tg_recv_sens_req(struct nfc_digital_dev ddev, void arg,
614	struct sk_buff *resp)
615	{
616	u8 sens_req;
617	int rc;
618
619	if (IS_ERR(resp)) {
620	rc = PTR_ERR(resp);
621	resp = NULL;
622	goto exit;
623	}
624
625	sens_req = resp->data[0];
626
627	if (!resp->len \|\| (sens_req != DIGITAL_CMD_SENS_REQ &&
628	sens_req != DIGITAL_CMD_ALL_REQ)) {
629	rc = -EINVAL;
630	goto exit;
631	}
632
633	rc = digital_tg_send_sens_res(ddev);
634
635	exit:
636	if (rc)
637	digital_poll_next_tech(ddev);
638
639	dev_kfree_skb(resp);
640	}
641
642	int digital_tg_send_sensf_res(struct nfc_digital_dev *ddev,
643	struct digital_sensf_req *sensf_req)
644	{
645	struct sk_buff *skb;
646	u8 size;
647	int rc;
648	struct digital_sensf_res *sensf_res;
649
650	size = sizeof(struct digital_sensf_res);
651
652	if (sensf_req->rc != DIGITAL_SENSF_REQ_RC_NONE)
653	size -= sizeof(sensf_res->rd);
654
655	skb = digital_skb_alloc(ddev, size);
656	if (!skb)
657	return -ENOMEM;
658
659	skb_put(skb, size);
660
661	sensf_res = (struct digital_sensf_res *)skb->data;
662
663	memset(sensf_res, 0, size);
664
665	sensf_res->cmd = DIGITAL_CMD_SENSF_RES;
666	sensf_res->nfcid2[0] = DIGITAL_SENSF_NFCID2_NFC_DEP_B1;
667	sensf_res->nfcid2[1] = DIGITAL_SENSF_NFCID2_NFC_DEP_B2;
668	get_random_bytes(&sensf_res->nfcid2[2], 6);
669
670	switch (sensf_req->rc) {
671	case DIGITAL_SENSF_REQ_RC_SC:
672	sensf_res->rd[0] = sensf_req->sc1;
673	sensf_res->rd[1] = sensf_req->sc2;
674	break;
675	case DIGITAL_SENSF_REQ_RC_AP:
676	sensf_res->rd[0] = DIGITAL_SENSF_RES_RD_AP_B1;
677	sensf_res->rd[1] = DIGITAL_SENSF_RES_RD_AP_B2;
678	break;
679	}
680
681	*skb_push(skb, sizeof(u8)) = size + 1;
682
683	if (!DIGITAL_DRV_CAPS_TG_CRC(ddev))
684	digital_skb_add_crc_f(skb);
685
686	rc = digital_tg_send_cmd(ddev, skb, 300,
687	digital_tg_recv_atr_req, NULL);
688	if (rc)
689	kfree_skb(skb);
690
691	return rc;
692	}
693
694	void digital_tg_recv_sensf_req(struct nfc_digital_dev ddev, void arg,
695	struct sk_buff *resp)
696	{
697	struct digital_sensf_req *sensf_req;
698	int rc;
699
700	if (IS_ERR(resp)) {
701	rc = PTR_ERR(resp);
702	resp = NULL;
703	goto exit;
704	}
705
706	if (!DIGITAL_DRV_CAPS_TG_CRC(ddev)) {
707	rc = digital_skb_check_crc_f(resp);
708	if (rc) {
709	PROTOCOL_ERR("6.4.1.8");
710	goto exit;
711	}
712	}
713
714	if (resp->len != sizeof(struct digital_sensf_req) + 1) {
715	rc = -EINVAL;
716	goto exit;
717	}
718
719	skb_pull(resp, 1);
720	sensf_req = (struct digital_sensf_req *)resp->data;
721
722	if (sensf_req->cmd != DIGITAL_CMD_SENSF_REQ) {
723	rc = -EINVAL;
724	goto exit;
725	}
726
727	rc = digital_tg_send_sensf_res(ddev, sensf_req);
728
729	exit:
730	if (rc)
731	digital_poll_next_tech(ddev);
732
733	dev_kfree_skb(resp);
734	}
735
736	int digital_tg_listen_nfca(struct nfc_digital_dev *ddev, u8 rf_tech)
737	{
738	int rc;
739
740	rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH, rf_tech);
741	if (rc)
742	return rc;
743
744	rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
745	NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
746	if (rc)
747	return rc;
748
749	return digital_tg_listen(ddev, 300, digital_tg_recv_sens_req, NULL);
750	}
751
752	int digital_tg_listen_nfcf(struct nfc_digital_dev *ddev, u8 rf_tech)
753	{
754	int rc;
755	u8 *nfcid2;
756
757	rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH, rf_tech);
758	if (rc)
759	return rc;
760
761	rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
762	NFC_DIGITAL_FRAMING_NFCF_NFC_DEP);
763	if (rc)
764	return rc;
765
766	nfcid2 = kzalloc(NFC_NFCID2_MAXSIZE, GFP_KERNEL);
767	if (!nfcid2)
768	return -ENOMEM;
769
770	nfcid2[0] = DIGITAL_SENSF_NFCID2_NFC_DEP_B1;
771	nfcid2[1] = DIGITAL_SENSF_NFCID2_NFC_DEP_B2;
772	get_random_bytes(nfcid2 + 2, NFC_NFCID2_MAXSIZE - 2);
773
774	return digital_tg_listen(ddev, 300, digital_tg_recv_sensf_req, nfcid2);
775	}