Commit 8c0695e4 authored by Thierry Escande's avatar Thierry Escande Committed by Samuel Ortiz
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NFC Digital: Add NFC-F technology support 



This adds polling support for NFC-F technology at 212 kbits/s and 424
kbits/s. A user space application like neard can send type 3 tag
commands through the NFC core.

Process flow for NFC-F detection is as follow:

1 - The digital stack sends the SENSF_REQ command to the NFC device.
2 - A peer device replies with a SENSF_RES response.
3   - The digital stack notifies the NFC core of the presence of a
      target in the operation field and passes the target NFCID2.

This also adds support for CRC calculation of type CRC-F. The CRC
calculation is handled by the digital stack if the NFC device doesn't
support it.

Signed-off-by: default avatarThierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: default avatarSamuel Ortiz <sameo@linux.intel.com>
parent 2c66daec

net/nfc/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ menuconfig NFC 
config NFC_DIGITAL

	depends on NFC

	select CRC_CCITT

	select CRC_ITU_T

	tristate "NFC Digital Protocol stack support"

	default n

	help

net/nfc/digital.h

+13 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <net/nfc/digital.h>



#include <linux/crc-ccitt.h>

#include <linux/crc-itu-t.h>



#define PR_DBG(fmt, ...)  pr_debug("%s: " fmt "\n", __func__, ##__VA_ARGS__)

#define PR_ERR(fmt, ...)  pr_err("%s: " fmt "\n", __func__, ##__VA_ARGS__)
@@ -64,6 +65,7 @@ static inline int digital_in_send_cmd(struct nfc_digital_dev *ddev, 
void digital_poll_next_tech(struct nfc_digital_dev *ddev);



int digital_in_send_sens_req(struct nfc_digital_dev *ddev, u8 rf_tech);

int digital_in_send_sensf_req(struct nfc_digital_dev *ddev, u8 rf_tech);



int digital_target_found(struct nfc_digital_dev *ddev,

			 struct nfc_target *target, u8 protocol);
@@ -74,6 +76,7 @@ typedef u16 (*crc_func_t)(u16, const u8 *, size_t); 


#define CRC_A_INIT 0x6363

#define CRC_B_INIT 0xFFFF

#define CRC_F_INIT 0x0000



void digital_skb_add_crc(struct sk_buff *skb, crc_func_t crc_func, u16 init,

			 u8 bitwise_inv, u8 msb_first);
@@ -88,6 +91,11 @@ static inline void digital_skb_add_crc_b(struct sk_buff *skb) 
	digital_skb_add_crc(skb, crc_ccitt, CRC_B_INIT, 1, 0);

}



static inline void digital_skb_add_crc_f(struct sk_buff *skb)

{

	digital_skb_add_crc(skb, crc_itu_t, CRC_F_INIT, 0, 1);

}



static inline void digital_skb_add_crc_none(struct sk_buff *skb)

{

	return;
@@ -106,6 +114,11 @@ static inline int digital_skb_check_crc_b(struct sk_buff *skb) 
	return digital_skb_check_crc(skb, crc_ccitt, CRC_B_INIT, 1, 0);

}



static inline int digital_skb_check_crc_f(struct sk_buff *skb)

{

	return digital_skb_check_crc(skb, crc_itu_t, CRC_F_INIT, 0, 1);

}



static inline int digital_skb_check_crc_none(struct sk_buff *skb)

{

	return 0;

net/nfc/digital_core.c

+18 −0
Original line number Diff line number Diff line
@@ -20,6 +20,8 @@ 
#define DIGITAL_PROTO_NFCA_RF_TECH \

	(NFC_PROTO_JEWEL_MASK | NFC_PROTO_MIFARE_MASK)



#define DIGITAL_PROTO_NFCF_RF_TECH (NFC_PROTO_FELICA_MASK)



struct digital_cmd {

	struct list_head queue;
@@ -252,6 +254,12 @@ int digital_target_found(struct nfc_digital_dev *ddev, 
		add_crc = digital_skb_add_crc_a;

		break;



	case NFC_PROTO_FELICA:

		framing = NFC_DIGITAL_FRAMING_NFCF_T3T;

		check_crc = digital_skb_check_crc_f;

		add_crc = digital_skb_add_crc_f;

		break;



	default:

		PR_ERR("Invalid protocol %d", protocol);

		return -EINVAL;
@@ -383,6 +391,14 @@ static int digital_start_poll(struct nfc_dev *nfc_dev, __u32 im_protocols, 
		digital_add_poll_tech(ddev, NFC_DIGITAL_RF_TECH_106A,

				      digital_in_send_sens_req);



	if (im_protocols & DIGITAL_PROTO_NFCF_RF_TECH) {

		digital_add_poll_tech(ddev, NFC_DIGITAL_RF_TECH_212F,

				      digital_in_send_sensf_req);



		digital_add_poll_tech(ddev, NFC_DIGITAL_RF_TECH_424F,

				      digital_in_send_sensf_req);

	}



	if (!ddev->poll_tech_count) {

		PR_ERR("Unsupported protocols: im=0x%x, tm=0x%x",

		       matching_im_protocols, matching_tm_protocols);
@@ -560,6 +576,8 @@ struct nfc_digital_dev *nfc_digital_allocate_device(struct nfc_digital_ops *ops, 
		ddev->protocols |= NFC_PROTO_JEWEL_MASK;

	if (supported_protocols & NFC_PROTO_MIFARE_MASK)

		ddev->protocols |= NFC_PROTO_MIFARE_MASK;

	if (supported_protocols & NFC_PROTO_FELICA_MASK)

		ddev->protocols |= NFC_PROTO_FELICA_MASK;



	ddev->tx_headroom = tx_headroom + DIGITAL_MAX_HEADER_LEN;

	ddev->tx_tailroom = tx_tailroom + DIGITAL_CRC_LEN;

net/nfc/digital_technology.c

+121 −0
Original line number Diff line number Diff line
@@ -37,6 +37,17 @@ 
#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;
@@ -49,6 +60,25 @@ struct digital_sel_req { 
	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);
@@ -344,3 +374,94 @@ int digital_in_recv_mifare_res(struct sk_buff *resp) 
	/* 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;

	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;



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



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;

}

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