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linux-next/net/nfc/digital_dep.c
Thierry Escande 1c7a4c24fb NFC Digital: Add target NFC-DEP support 
This adds support for NFC-DEP target mode for NFC-A and NFC-F
technologies.

If the driver provides it, the stack uses an automatic mode for
technology detection and automatic anti-collision. Otherwise the stack
tries to use non-automatic synchronization and listens for SENS_REQ and
SENSF_REQ commands.

The detection, activation, and data exchange procedures work exactly
the same way as in initiator mode, as described in the previous
commits, except that the digital stack waits for commands and sends
responses back to the peer device.

Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2013-09-25 02:02:28 +02:00

728 lines
15 KiB
C
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/*
* 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.
*
*/
#include "digital.h"
#define DIGITAL_NFC_DEP_FRAME_DIR_OUT 0xD4
#define DIGITAL_NFC_DEP_FRAME_DIR_IN 0xD5
#define DIGITAL_NFC_DEP_NFCA_SOD_SB 0xF0
#define DIGITAL_CMD_ATR_REQ 0x00
#define DIGITAL_CMD_ATR_RES 0x01
#define DIGITAL_CMD_PSL_REQ 0x04
#define DIGITAL_CMD_PSL_RES 0x05
#define DIGITAL_CMD_DEP_REQ 0x06
#define DIGITAL_CMD_DEP_RES 0x07
#define DIGITAL_ATR_REQ_MIN_SIZE 16
#define DIGITAL_ATR_REQ_MAX_SIZE 64
#define DIGITAL_NFCID3_LEN ((u8)8)
#define DIGITAL_LR_BITS_PAYLOAD_SIZE_254B 0x30
#define DIGITAL_GB_BIT 0x02
#define DIGITAL_NFC_DEP_PFB_TYPE(pfb) ((pfb) & 0xE0)
#define DIGITAL_NFC_DEP_PFB_TIMEOUT_BIT 0x10
#define DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb) \
((pfb) & DIGITAL_NFC_DEP_PFB_TIMEOUT_BIT)
#define DIGITAL_NFC_DEP_MI_BIT_SET(pfb) ((pfb) & 0x10)
#define DIGITAL_NFC_DEP_NAD_BIT_SET(pfb) ((pfb) & 0x08)
#define DIGITAL_NFC_DEP_DID_BIT_SET(pfb) ((pfb) & 0x04)
#define DIGITAL_NFC_DEP_PFB_PNI(pfb) ((pfb) & 0x03)
#define DIGITAL_NFC_DEP_PFB_I_PDU 0x00
#define DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU 0x40
#define DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU 0x80
struct digital_atr_req {
u8 dir;
u8 cmd;
u8 nfcid3[10];
u8 did;
u8 bs;
u8 br;
u8 pp;
u8 gb[0];
} __packed;
struct digital_atr_res {
u8 dir;
u8 cmd;
u8 nfcid3[10];
u8 did;
u8 bs;
u8 br;
u8 to;
u8 pp;
u8 gb[0];
} __packed;
struct digital_psl_req {
u8 dir;
u8 cmd;
u8 did;
u8 brs;
u8 fsl;
} __packed;
struct digital_psl_res {
u8 dir;
u8 cmd;
u8 did;
} __packed;
struct digital_dep_req_res {
u8 dir;
u8 cmd;
u8 pfb;
} __packed;
static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
struct sk_buff *resp);
static void digital_skb_push_dep_sod(struct nfc_digital_dev *ddev,
struct sk_buff *skb)
{
skb_push(skb, sizeof(u8));
skb->data[0] = skb->len;
if (ddev->curr_rf_tech == NFC_DIGITAL_RF_TECH_106A)
*skb_push(skb, sizeof(u8)) = DIGITAL_NFC_DEP_NFCA_SOD_SB;
}
static int digital_skb_pull_dep_sod(struct nfc_digital_dev *ddev,
struct sk_buff *skb)
{
u8 size;
if (skb->len < 2)
return -EIO;
if (ddev->curr_rf_tech == NFC_DIGITAL_RF_TECH_106A)
skb_pull(skb, sizeof(u8));
size = skb->data[0];
if (size != skb->len)
return -EIO;
skb_pull(skb, sizeof(u8));
return 0;
}
static void digital_in_recv_atr_res(struct nfc_digital_dev *ddev, void *arg,
struct sk_buff *resp)
{
struct nfc_target *target = arg;
struct digital_atr_res *atr_res;
u8 gb_len;
int rc;
if (IS_ERR(resp)) {
rc = PTR_ERR(resp);
resp = NULL;
goto exit;
}
rc = ddev->skb_check_crc(resp);
if (rc) {
PROTOCOL_ERR("14.4.1.6");
goto exit;
}
rc = digital_skb_pull_dep_sod(ddev, resp);
if (rc) {
PROTOCOL_ERR("14.4.1.2");
goto exit;
}
if (resp->len < sizeof(struct digital_atr_res)) {
rc = -EIO;
goto exit;
}
gb_len = resp->len - sizeof(struct digital_atr_res);
atr_res = (struct digital_atr_res *)resp->data;
rc = nfc_set_remote_general_bytes(ddev->nfc_dev, atr_res->gb, gb_len);
if (rc)
goto exit;
rc = nfc_dep_link_is_up(ddev->nfc_dev, target->idx, NFC_COMM_ACTIVE,
NFC_RF_INITIATOR);
ddev->curr_nfc_dep_pni = 0;
exit:
dev_kfree_skb(resp);
if (rc)
ddev->curr_protocol = 0;
}
int digital_in_send_atr_req(struct nfc_digital_dev *ddev,
struct nfc_target *target, __u8 comm_mode, __u8 *gb,
size_t gb_len)
{
struct sk_buff *skb;
struct digital_atr_req *atr_req;
uint size;
size = DIGITAL_ATR_REQ_MIN_SIZE + gb_len;
if (size > DIGITAL_ATR_REQ_MAX_SIZE) {
PROTOCOL_ERR("14.6.1.1");
return -EINVAL;
}
skb = digital_skb_alloc(ddev, size);
if (!skb)
return -ENOMEM;
skb_put(skb, sizeof(struct digital_atr_req));
atr_req = (struct digital_atr_req *)skb->data;
memset(atr_req, 0, sizeof(struct digital_atr_req));
atr_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT;
atr_req->cmd = DIGITAL_CMD_ATR_REQ;
if (target->nfcid2_len)
memcpy(atr_req->nfcid3, target->nfcid2,
max(target->nfcid2_len, DIGITAL_NFCID3_LEN));
else
get_random_bytes(atr_req->nfcid3, DIGITAL_NFCID3_LEN);
atr_req->did = 0;
atr_req->bs = 0;
atr_req->br = 0;
atr_req->pp = DIGITAL_LR_BITS_PAYLOAD_SIZE_254B;
if (gb_len) {
atr_req->pp |= DIGITAL_GB_BIT;
memcpy(skb_put(skb, gb_len), gb, gb_len);
}
digital_skb_push_dep_sod(ddev, skb);
ddev->skb_add_crc(skb);
digital_in_send_cmd(ddev, skb, 500, digital_in_recv_atr_res, target);
return 0;
}
static int digital_in_send_rtox(struct nfc_digital_dev *ddev,
struct digital_data_exch *data_exch, u8 rtox)
{
struct digital_dep_req_res *dep_req;
struct sk_buff *skb;
int rc;
skb = digital_skb_alloc(ddev, 1);
if (!skb)
return -ENOMEM;
*skb_put(skb, 1) = rtox;
skb_push(skb, sizeof(struct digital_dep_req_res));
dep_req = (struct digital_dep_req_res *)skb->data;
dep_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT;
dep_req->cmd = DIGITAL_CMD_DEP_REQ;
dep_req->pfb = DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU |
DIGITAL_NFC_DEP_PFB_TIMEOUT_BIT;
digital_skb_push_dep_sod(ddev, skb);
ddev->skb_add_crc(skb);
rc = digital_in_send_cmd(ddev, skb, 1500, digital_in_recv_dep_res,
data_exch);
return rc;
}
static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
struct sk_buff *resp)
{
struct digital_data_exch *data_exch = arg;
struct digital_dep_req_res *dep_res;
u8 pfb;
uint size;
int rc;
if (IS_ERR(resp)) {
rc = PTR_ERR(resp);
resp = NULL;
goto exit;
}
rc = ddev->skb_check_crc(resp);
if (rc) {
PROTOCOL_ERR("14.4.1.6");
goto error;
}
rc = digital_skb_pull_dep_sod(ddev, resp);
if (rc) {
PROTOCOL_ERR("14.4.1.2");
goto exit;
}
dep_res = (struct digital_dep_req_res *)resp->data;
if (resp->len < sizeof(struct digital_dep_req_res) ||
dep_res->dir != DIGITAL_NFC_DEP_FRAME_DIR_IN ||
dep_res->cmd != DIGITAL_CMD_DEP_RES) {
rc = -EIO;
goto error;
}
pfb = dep_res->pfb;
switch (DIGITAL_NFC_DEP_PFB_TYPE(pfb)) {
case DIGITAL_NFC_DEP_PFB_I_PDU:
if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) {
PROTOCOL_ERR("14.12.3.3");
rc = -EIO;
goto error;
}
ddev->curr_nfc_dep_pni =
DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1);
rc = 0;
break;
case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU:
PR_ERR("Received a ACK/NACK PDU");
rc = -EIO;
goto error;
case DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU:
if (!DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb)) {
rc = -EINVAL;
goto error;
}
rc = digital_in_send_rtox(ddev, data_exch, resp->data[3]);
if (rc)
goto error;
kfree_skb(resp);
return;
}
if (DIGITAL_NFC_DEP_MI_BIT_SET(pfb)) {
PR_ERR("MI bit set. Chained PDU not supported.");
rc = -EIO;
goto error;
}
size = sizeof(struct digital_dep_req_res);
if (DIGITAL_NFC_DEP_DID_BIT_SET(pfb))
size++;
if (size > resp->len) {
rc = -EIO;
goto error;
}
skb_pull(resp, size);
exit:
data_exch->cb(data_exch->cb_context, resp, rc);
error:
kfree(data_exch);
if (rc)
kfree_skb(resp);
}
int digital_in_send_dep_req(struct nfc_digital_dev *ddev,
struct nfc_target *target, struct sk_buff *skb,
struct digital_data_exch *data_exch)
{
struct digital_dep_req_res *dep_req;
skb_push(skb, sizeof(struct digital_dep_req_res));
dep_req = (struct digital_dep_req_res *)skb->data;
dep_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT;
dep_req->cmd = DIGITAL_CMD_DEP_REQ;
dep_req->pfb = ddev->curr_nfc_dep_pni;
digital_skb_push_dep_sod(ddev, skb);
ddev->skb_add_crc(skb);
return digital_in_send_cmd(ddev, skb, 1500, digital_in_recv_dep_res,
data_exch);
}
static void digital_tg_recv_dep_req(struct nfc_digital_dev *ddev, void *arg,
struct sk_buff *resp)
{
int rc;
struct digital_dep_req_res *dep_req;
size_t size;
if (IS_ERR(resp)) {
rc = PTR_ERR(resp);
resp = NULL;
goto exit;
}
rc = ddev->skb_check_crc(resp);
if (rc) {
PROTOCOL_ERR("14.4.1.6");
goto exit;
}
rc = digital_skb_pull_dep_sod(ddev, resp);
if (rc) {
PROTOCOL_ERR("14.4.1.2");
goto exit;
}
size = sizeof(struct digital_dep_req_res);
dep_req = (struct digital_dep_req_res *)resp->data;
if (resp->len < size || dep_req->dir != DIGITAL_NFC_DEP_FRAME_DIR_OUT ||
dep_req->cmd != DIGITAL_CMD_DEP_REQ) {
rc = -EIO;
goto exit;
}
if (DIGITAL_NFC_DEP_DID_BIT_SET(dep_req->pfb))
size++;
if (resp->len < size) {
rc = -EIO;
goto exit;
}
switch (DIGITAL_NFC_DEP_PFB_TYPE(dep_req->pfb)) {
case DIGITAL_NFC_DEP_PFB_I_PDU:
PR_DBG("DIGITAL_NFC_DEP_PFB_I_PDU");
ddev->curr_nfc_dep_pni = DIGITAL_NFC_DEP_PFB_PNI(dep_req->pfb);
break;
case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU:
PR_ERR("Received a ACK/NACK PDU");
rc = -EINVAL;
goto exit;
break;
case DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU:
PR_ERR("Received a SUPERVISOR PDU");
rc = -EINVAL;
goto exit;
break;
}
skb_pull(resp, size);
rc = nfc_tm_data_received(ddev->nfc_dev, resp);
exit:
if (rc)
kfree_skb(resp);
}
int digital_tg_send_dep_res(struct nfc_digital_dev *ddev, struct sk_buff *skb)
{
struct digital_dep_req_res *dep_res;
skb_push(skb, sizeof(struct digital_dep_req_res));
dep_res = (struct digital_dep_req_res *)skb->data;
dep_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN;
dep_res->cmd = DIGITAL_CMD_DEP_RES;
dep_res->pfb = ddev->curr_nfc_dep_pni;
digital_skb_push_dep_sod(ddev, skb);
ddev->skb_add_crc(skb);
return digital_tg_send_cmd(ddev, skb, 1500, digital_tg_recv_dep_req,
NULL);
}
static void digital_tg_send_psl_res_complete(struct nfc_digital_dev *ddev,
void *arg, struct sk_buff *resp)
{
u8 rf_tech = PTR_ERR(arg);
if (IS_ERR(resp))
return;
digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH, rf_tech);
digital_tg_listen(ddev, 1500, digital_tg_recv_dep_req, NULL);
dev_kfree_skb(resp);
}
static int digital_tg_send_psl_res(struct nfc_digital_dev *ddev, u8 did,
u8 rf_tech)
{
struct digital_psl_res *psl_res;
struct sk_buff *skb;
int rc;
skb = digital_skb_alloc(ddev, sizeof(struct digital_psl_res));
if (!skb)
return -ENOMEM;
skb_put(skb, sizeof(struct digital_psl_res));
psl_res = (struct digital_psl_res *)skb->data;
psl_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN;
psl_res->cmd = DIGITAL_CMD_PSL_RES;
psl_res->did = did;
digital_skb_push_dep_sod(ddev, skb);
ddev->skb_add_crc(skb);
rc = digital_tg_send_cmd(ddev, skb, 0, digital_tg_send_psl_res_complete,
ERR_PTR(rf_tech));
if (rc)
kfree_skb(skb);
return rc;
}
static void digital_tg_recv_psl_req(struct nfc_digital_dev *ddev, void *arg,
struct sk_buff *resp)
{
int rc;
struct digital_psl_req *psl_req;
u8 rf_tech;
u8 dsi;
if (IS_ERR(resp)) {
rc = PTR_ERR(resp);
resp = NULL;
goto exit;
}
rc = ddev->skb_check_crc(resp);
if (rc) {
PROTOCOL_ERR("14.4.1.6");
goto exit;
}
rc = digital_skb_pull_dep_sod(ddev, resp);
if (rc) {
PROTOCOL_ERR("14.4.1.2");
goto exit;
}
psl_req = (struct digital_psl_req *)resp->data;
if (resp->len != sizeof(struct digital_psl_req) ||
psl_req->dir != DIGITAL_NFC_DEP_FRAME_DIR_OUT ||
psl_req->cmd != DIGITAL_CMD_PSL_REQ) {
rc = -EIO;
goto exit;
}
dsi = (psl_req->brs >> 3) & 0x07;
switch (dsi) {
case 0:
rf_tech = NFC_DIGITAL_RF_TECH_106A;
break;
case 1:
rf_tech = NFC_DIGITAL_RF_TECH_212F;
break;
case 2:
rf_tech = NFC_DIGITAL_RF_TECH_424F;
break;
default:
PR_ERR("Unsuported dsi value %d", dsi);
goto exit;
}
rc = digital_tg_send_psl_res(ddev, psl_req->did, rf_tech);
exit:
kfree_skb(resp);
}
static void digital_tg_send_atr_res_complete(struct nfc_digital_dev *ddev,
void *arg, struct sk_buff *resp)
{
int offset;
if (IS_ERR(resp)) {
digital_poll_next_tech(ddev);
return;
}
offset = 2;
if (resp->data[0] == DIGITAL_NFC_DEP_NFCA_SOD_SB)
offset++;
if (resp->data[offset] == DIGITAL_CMD_PSL_REQ)
digital_tg_recv_psl_req(ddev, arg, resp);
else
digital_tg_recv_dep_req(ddev, arg, resp);
}
static int digital_tg_send_atr_res(struct nfc_digital_dev *ddev,
struct digital_atr_req *atr_req)
{
struct digital_atr_res *atr_res;
struct sk_buff *skb;
u8 *gb;
size_t gb_len;
int rc;
gb = nfc_get_local_general_bytes(ddev->nfc_dev, &gb_len);
if (!gb)
gb_len = 0;
skb = digital_skb_alloc(ddev, sizeof(struct digital_atr_res) + gb_len);
if (!skb)
return -ENOMEM;
skb_put(skb, sizeof(struct digital_atr_res));
atr_res = (struct digital_atr_res *)skb->data;
memset(atr_res, 0, sizeof(struct digital_atr_res));
atr_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN;
atr_res->cmd = DIGITAL_CMD_ATR_RES;
memcpy(atr_res->nfcid3, atr_req->nfcid3, sizeof(atr_req->nfcid3));
atr_res->to = 8;
atr_res->pp = DIGITAL_LR_BITS_PAYLOAD_SIZE_254B;
if (gb_len) {
skb_put(skb, gb_len);
atr_res->pp |= DIGITAL_GB_BIT;
memcpy(atr_res->gb, gb, gb_len);
}
digital_skb_push_dep_sod(ddev, skb);
ddev->skb_add_crc(skb);
rc = digital_tg_send_cmd(ddev, skb, 999,
digital_tg_send_atr_res_complete, NULL);
if (rc) {
kfree_skb(skb);
return rc;
}
return rc;
}
void digital_tg_recv_atr_req(struct nfc_digital_dev *ddev, void *arg,
struct sk_buff *resp)
{
int rc;
struct digital_atr_req *atr_req;
size_t gb_len, min_size;
if (IS_ERR(resp)) {
rc = PTR_ERR(resp);
resp = NULL;
goto exit;
}
if (!resp->len) {
rc = -EIO;
goto exit;
}
if (resp->data[0] == DIGITAL_NFC_DEP_NFCA_SOD_SB) {
min_size = DIGITAL_ATR_REQ_MIN_SIZE + 2;
ddev->curr_rf_tech = NFC_DIGITAL_RF_TECH_106A;
ddev->skb_add_crc = digital_skb_add_crc_a;
ddev->skb_check_crc = digital_skb_check_crc_a;
} else {
min_size = DIGITAL_ATR_REQ_MIN_SIZE + 1;
ddev->curr_rf_tech = NFC_DIGITAL_RF_TECH_212F;
ddev->skb_add_crc = digital_skb_add_crc_f;
ddev->skb_check_crc = digital_skb_check_crc_f;
}
if (resp->len < min_size) {
rc = -EIO;
goto exit;
}
if (DIGITAL_DRV_CAPS_TG_CRC(ddev)) {
ddev->skb_add_crc = digital_skb_add_crc_none;
ddev->skb_check_crc = digital_skb_check_crc_none;
}
rc = ddev->skb_check_crc(resp);
if (rc) {
PROTOCOL_ERR("14.4.1.6");
goto exit;
}
rc = digital_skb_pull_dep_sod(ddev, resp);
if (rc) {
PROTOCOL_ERR("14.4.1.2");
goto exit;
}
atr_req = (struct digital_atr_req *)resp->data;
if (atr_req->dir != DIGITAL_NFC_DEP_FRAME_DIR_OUT ||
atr_req->cmd != DIGITAL_CMD_ATR_REQ) {
rc = -EINVAL;
goto exit;
}
rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED);
if (rc)
goto exit;
rc = digital_tg_send_atr_res(ddev, atr_req);
if (rc)
goto exit;
gb_len = resp->len - sizeof(struct digital_atr_req);
rc = nfc_tm_activated(ddev->nfc_dev, NFC_PROTO_NFC_DEP_MASK,
NFC_COMM_PASSIVE, atr_req->gb, gb_len);
if (rc)
goto exit;
ddev->poll_tech_count = 0;
rc = 0;
exit:
if (rc)
digital_poll_next_tech(ddev);
dev_kfree_skb(resp);
}
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