NFC: st21nfcb: Add support for secure element

The st21nfcb chipset has 3 SWP (Single Wire Protocol) lines and
supports up to 3 secure elements (UICC/eSE and µSD in the future).

Some st21nfcb firmware does not support the nci command
nci_nfcee_mode_set(NCI_NFCEE_DISABLE). For this reason, we assume
2 secures elements are always present (UICC and eSE).
They will be added to the SE list once successfully activated and
they will be available only after running through enable_se
handler or when the poll in listen mode is started.

During initialization, the white_list will be always set assuming
both UICC & eSE are present.

On eSE activation, the ATR bytes are fetched to build the command
exchange timeout.

The se_io hook will allow to transfer data over SWP. 2 kind of
events may appear data is sent over:
- ST21NFCB_EVT_TRANSMIT_DATA when receiving an apdu answer
- ST21NFCB_EVT_WTX_REQUEST when the secure element needs more time
  than expected to process a command. If this timeout expires, we
  send a software reset, and then a hardware one if it still fails.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/nfc/st21nfcb/Makefile

@@ -2,7 +2,7 @@
 # Makefile for ST21NFCB NCI based NFC driver
 #
 
-st21nfcb_nci-objs = ndlc.o st21nfcb.o
+st21nfcb_nci-objs = ndlc.o st21nfcb.o st21nfcb_se.o
 obj-$(CONFIG_NFC_ST21NFCB)     += st21nfcb_nci.o
 
 st21nfcb_i2c-objs = i2c.o

drivers/nfc/st21nfcb/st21nfcb.c

@@ -22,6 +22,7 @@
 #include <net/nfc/nci_core.h>
 
 #include "st21nfcb.h"
+#include "st21nfcb_se.h"
 
 #define DRIVER_DESC "NCI NFC driver for ST21NFCB"
 
@@ -78,6 +79,13 @@ static struct nci_ops st21nfcb_nci_ops = {
 	.close = st21nfcb_nci_close,
 	.send = st21nfcb_nci_send,
 	.get_rfprotocol = st21nfcb_nci_get_rfprotocol,
+	.discover_se = st21nfcb_nci_discover_se,
+	.enable_se = st21nfcb_nci_enable_se,
+	.disable_se = st21nfcb_nci_disable_se,
+	.se_io = st21nfcb_nci_se_io,
+	.hci_load_session = st21nfcb_hci_load_session,
+	.hci_event_received = st21nfcb_hci_event_received,
+	.hci_cmd_received = st21nfcb_hci_cmd_received,
 };
 
 int st21nfcb_nci_probe(struct llt_ndlc *ndlc, int phy_headroom,
@@ -114,9 +122,10 @@ int st21nfcb_nci_probe(struct llt_ndlc *ndlc, int phy_headroom,
 	if (r) {
 		pr_err("Cannot register nfc device to nci core\n");
 		nci_free_device(ndlc->ndev);
+		return r;
 	}
 
-	return r;
+	return st21nfcb_se_init(ndlc->ndev);
 }
 EXPORT_SYMBOL_GPL(st21nfcb_nci_probe);
 

drivers/nfc/st21nfcb/st21nfcb.h

@@ -19,6 +19,7 @@
 #ifndef __LOCAL_ST21NFCB_H_
 #define __LOCAL_ST21NFCB_H_
 
+#include "st21nfcb_se.h"
 #include "ndlc.h"
 
 /* Define private flags: */
@@ -27,6 +28,7 @@
 struct st21nfcb_nci_info {
 	struct llt_ndlc *ndlc;
 	unsigned long flags;
+	struct st21nfcb_se_info se_info;
 };
 
 void st21nfcb_nci_remove(struct nci_dev *ndev);

drivers/nfc/st21nfcb/st21nfcb_se.c

+/*
+ * NCI based Driver for STMicroelectronics NFC Chip
+ *
+ * Copyright (C) 2014  STMicroelectronics SAS. All rights reserved.
+ *
+ * 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 that 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/module.h>
+#include <linux/nfc.h>
+#include <linux/delay.h>
+#include <net/nfc/nci.h>
+#include <net/nfc/nci_core.h>
+
+#include "st21nfcb.h"
+#include "st21nfcb_se.h"
+
+struct st21nfcb_pipe_info {
+	u8 pipe_state;
+	u8 src_host_id;
+	u8 src_gate_id;
+	u8 dst_host_id;
+	u8 dst_gate_id;
+} __packed;
+
+/* Hosts */
+#define ST21NFCB_HOST_CONTROLLER_ID     0x00
+#define ST21NFCB_TERMINAL_HOST_ID       0x01
+#define ST21NFCB_UICC_HOST_ID           0x02
+#define ST21NFCB_ESE_HOST_ID            0xc0
+
+/* Gates */
+#define ST21NFCB_DEVICE_MGNT_GATE       0x01
+#define ST21NFCB_APDU_READER_GATE       0xf0
+#define ST21NFCB_CONNECTIVITY_GATE      0x41
+
+/* Pipes */
+#define ST21NFCB_DEVICE_MGNT_PIPE               0x02
+
+/* Connectivity pipe only */
+#define ST21NFCB_SE_COUNT_PIPE_UICC             0x01
+/* Connectivity + APDU Reader pipe */
+#define ST21NFCB_SE_COUNT_PIPE_EMBEDDED         0x02
+
+#define ST21NFCB_SE_TO_HOT_PLUG			1000 /* msecs */
+#define ST21NFCB_SE_TO_PIPES			2000
+
+#define ST21NFCB_EVT_HOT_PLUG_IS_INHIBITED(x)   (x->data[0] & 0x80)
+
+#define NCI_HCI_APDU_PARAM_ATR                     0x01
+#define NCI_HCI_ADMIN_PARAM_SESSION_IDENTITY       0x01
+#define NCI_HCI_ADMIN_PARAM_WHITELIST              0x03
+#define NCI_HCI_ADMIN_PARAM_HOST_LIST              0x04
+
+#define ST21NFCB_EVT_SE_HARD_RESET		0x20
+#define ST21NFCB_EVT_TRANSMIT_DATA		0x10
+#define ST21NFCB_EVT_WTX_REQUEST		0x11
+#define ST21NFCB_EVT_SE_SOFT_RESET		0x11
+#define ST21NFCB_EVT_SE_END_OF_APDU_TRANSFER	0x21
+#define ST21NFCB_EVT_HOT_PLUG			0x03
+
+#define ST21NFCB_SE_MODE_OFF                    0x00
+#define ST21NFCB_SE_MODE_ON                     0x01
+
+#define ST21NFCB_EVT_CONNECTIVITY       0x10
+#define ST21NFCB_EVT_TRANSACTION        0x12
+
+#define ST21NFCB_DM_GETINFO             0x13
+#define ST21NFCB_DM_GETINFO_PIPE_LIST   0x02
+#define ST21NFCB_DM_GETINFO_PIPE_INFO   0x01
+#define ST21NFCB_DM_PIPE_CREATED        0x02
+#define ST21NFCB_DM_PIPE_OPEN           0x04
+#define ST21NFCB_DM_RF_ACTIVE           0x80
+#define ST21NFCB_DM_DISCONNECT          0x30
+
+#define ST21NFCB_DM_IS_PIPE_OPEN(p) \
+	((p & 0x0f) == (ST21NFCB_DM_PIPE_CREATED | ST21NFCB_DM_PIPE_OPEN))
+
+#define ST21NFCB_ATR_DEFAULT_BWI        0x04
+
+/*
+ * WT = 2^BWI/10[s], convert into msecs and add a secure
+ * room by increasing by 2 this timeout
+ */
+#define ST21NFCB_BWI_TO_TIMEOUT(x)      ((1 << x) * 200)
+#define ST21NFCB_ATR_GET_Y_FROM_TD(x)   (x >> 4)
+
+/* If TA is present bit 0 is set */
+#define ST21NFCB_ATR_TA_PRESENT(x) (x & 0x01)
+/* If TB is present bit 1 is set */
+#define ST21NFCB_ATR_TB_PRESENT(x) (x & 0x02)
+
+#define ST21NFCB_NUM_DEVICES           256
+
+static DECLARE_BITMAP(dev_mask, ST21NFCB_NUM_DEVICES);
+
+/* Here are the mandatory pipe for st21nfcb */
+static struct nci_hci_gate st21nfcb_gates[] = {
+	{NCI_HCI_ADMIN_GATE, NCI_HCI_ADMIN_PIPE,
+					ST21NFCB_HOST_CONTROLLER_ID},
+	{NCI_HCI_LINK_MGMT_GATE, NCI_HCI_LINK_MGMT_PIPE,
+					ST21NFCB_HOST_CONTROLLER_ID},
+	{ST21NFCB_DEVICE_MGNT_GATE, ST21NFCB_DEVICE_MGNT_PIPE,
+					ST21NFCB_HOST_CONTROLLER_ID},
+
+	/* Secure element pipes are created by secure element host */
+	{ST21NFCB_CONNECTIVITY_GATE, NCI_HCI_DO_NOT_OPEN_PIPE,
+					ST21NFCB_HOST_CONTROLLER_ID},
+	{ST21NFCB_APDU_READER_GATE, NCI_HCI_DO_NOT_OPEN_PIPE,
+					ST21NFCB_HOST_CONTROLLER_ID},
+};
+
+static u8 st21nfcb_se_get_bwi(struct nci_dev *ndev)
+{
+	int i;
+	u8 td;
+	struct st21nfcb_nci_info *info = nci_get_drvdata(ndev);
+
+	/* Bits 8 to 5 of the first TB for T=1 encode BWI from zero to nine */
+	for (i = 1; i < ST21NFCB_ESE_MAX_LENGTH; i++) {
+		td = ST21NFCB_ATR_GET_Y_FROM_TD(info->se_info.atr[i]);
+		if (ST21NFCB_ATR_TA_PRESENT(td))
+			i++;
+		if (ST21NFCB_ATR_TB_PRESENT(td)) {
+			i++;
+			return info->se_info.atr[i] >> 4;
+		}
+	}
+	return ST21NFCB_ATR_DEFAULT_BWI;
+}
+
+static void st21nfcb_se_get_atr(struct nci_dev *ndev)
+{
+	struct st21nfcb_nci_info *info = nci_get_drvdata(ndev);
+	int r;
+	struct sk_buff *skb;
+
+	r = nci_hci_get_param(ndev, ST21NFCB_APDU_READER_GATE,
+				NCI_HCI_APDU_PARAM_ATR, &skb);
+	if (r < 0)
+		return;
+
+	if (skb->len <= ST21NFCB_ESE_MAX_LENGTH) {
+		memcpy(info->se_info.atr, skb->data, skb->len);
+
+		info->se_info.wt_timeout =
+			ST21NFCB_BWI_TO_TIMEOUT(st21nfcb_se_get_bwi(ndev));
+	}
+	kfree_skb(skb);
+}
+
+int st21nfcb_hci_load_session(struct nci_dev *ndev)
+{
+	int i, j, r;
+	struct sk_buff *skb_pipe_list, *skb_pipe_info;
+	struct st21nfcb_pipe_info *dm_pipe_info;
+	u8 pipe_list[] = { ST21NFCB_DM_GETINFO_PIPE_LIST,
+			ST21NFCB_TERMINAL_HOST_ID};
+	u8 pipe_info[] = { ST21NFCB_DM_GETINFO_PIPE_INFO,
+			ST21NFCB_TERMINAL_HOST_ID, 0};
+
+	/* On ST21NFCB device pipes number are dynamics
+	 * If pipes are already created, hci_dev_up will fail.
+	 * Doing a clear all pipe is a bad idea because:
+	 * - It does useless EEPROM cycling
+	 * - It might cause issue for secure elements support
+	 * (such as removing connectivity or APDU reader pipe)
+	 * A better approach on ST21NFCB is to:
+	 * - get a pipe list for each host.
+	 * (eg: ST21NFCB_HOST_CONTROLLER_ID for now).
+	 * (TODO Later on UICC HOST and eSE HOST)
+	 * - get pipe information
+	 * - match retrieved pipe list in st21nfcb_gates
+	 * ST21NFCB_DEVICE_MGNT_GATE is a proprietary gate
+	 * with ST21NFCB_DEVICE_MGNT_PIPE.
+	 * Pipe can be closed and need to be open.
+	 */
+	r = nci_hci_connect_gate(ndev, ST21NFCB_HOST_CONTROLLER_ID,
+				ST21NFCB_DEVICE_MGNT_GATE,
+				ST21NFCB_DEVICE_MGNT_PIPE);
+	if (r < 0)
+		goto free_info;
+
+	/* Get pipe list */
+	r = nci_hci_send_cmd(ndev, ST21NFCB_DEVICE_MGNT_GATE,
+			ST21NFCB_DM_GETINFO, pipe_list, sizeof(pipe_list),
+			&skb_pipe_list);
+	if (r < 0)
+		goto free_info;
+
+	/* Complete the existing gate_pipe table */
+	for (i = 0; i < skb_pipe_list->len; i++) {
+		pipe_info[2] = skb_pipe_list->data[i];
+		r = nci_hci_send_cmd(ndev, ST21NFCB_DEVICE_MGNT_GATE,
+					ST21NFCB_DM_GETINFO, pipe_info,
+					sizeof(pipe_info), &skb_pipe_info);
+
+		if (r)
+			continue;
+
+		/*
+		 * Match pipe ID and gate ID
+		 * Output format from ST21NFC_DM_GETINFO is:
+		 * - pipe state (1byte)
+		 * - source hid (1byte)
+		 * - source gid (1byte)
+		 * - destination hid (1byte)
+		 * - destination gid (1byte)
+		 */
+		dm_pipe_info = (struct st21nfcb_pipe_info *)skb_pipe_info->data;
+		if (dm_pipe_info->dst_gate_id == ST21NFCB_APDU_READER_GATE &&
+		    dm_pipe_info->src_host_id != ST21NFCB_ESE_HOST_ID) {
+			pr_err("Unexpected apdu_reader pipe on host %x\n",
+			       dm_pipe_info->src_host_id);
+			continue;
+		}
+
+		for (j = 0; (j < ARRAY_SIZE(st21nfcb_gates)) &&
+		     (st21nfcb_gates[j].gate != dm_pipe_info->dst_gate_id); j++)
+			;
+
+		if (j < ARRAY_SIZE(st21nfcb_gates) &&
+		    st21nfcb_gates[j].gate == dm_pipe_info->dst_gate_id &&
+		    ST21NFCB_DM_IS_PIPE_OPEN(dm_pipe_info->pipe_state)) {
+			st21nfcb_gates[j].pipe = pipe_info[2];
+
+			ndev->hci_dev->gate2pipe[st21nfcb_gates[j].gate] =
+						st21nfcb_gates[j].pipe;
+			ndev->hci_dev->pipes[st21nfcb_gates[j].pipe].gate =
+						st21nfcb_gates[j].gate;
+			ndev->hci_dev->pipes[st21nfcb_gates[j].pipe].host =
+						dm_pipe_info->src_host_id;
+		}
+	}
+
+	memcpy(ndev->hci_dev->init_data.gates, st21nfcb_gates,
+	       sizeof(st21nfcb_gates));
+
+free_info:
+	kfree_skb(skb_pipe_info);
+	kfree_skb(skb_pipe_list);
+	return r;
+}
+EXPORT_SYMBOL_GPL(st21nfcb_hci_load_session);
+
+static void st21nfcb_hci_admin_event_received(struct nci_dev *ndev,
+					      u8 event, struct sk_buff *skb)
+{
+	struct st21nfcb_nci_info *info = nci_get_drvdata(ndev);
+
+	switch (event) {
+	case ST21NFCB_EVT_HOT_PLUG:
+		if (info->se_info.se_active) {
+			if (!ST21NFCB_EVT_HOT_PLUG_IS_INHIBITED(skb)) {
+				del_timer_sync(&info->se_info.se_active_timer);
+				info->se_info.se_active = false;
+				complete(&info->se_info.req_completion);
+			} else {
+				mod_timer(&info->se_info.se_active_timer,
+				      jiffies +
+				      msecs_to_jiffies(ST21NFCB_SE_TO_PIPES));
+			}
+		}
+	break;
+	}
+}
+
+static int st21nfcb_hci_apdu_reader_event_received(struct nci_dev *ndev,
+						   u8 event,
+						   struct sk_buff *skb)
+{
+	int r = 0;
+	struct st21nfcb_nci_info *info = nci_get_drvdata(ndev);
+
+	pr_debug("apdu reader gate event: %x\n", event);
+
+	switch (event) {
+	case ST21NFCB_EVT_TRANSMIT_DATA:
+		del_timer_sync(&info->se_info.bwi_timer);
+		info->se_info.bwi_active = false;
+		info->se_info.cb(info->se_info.cb_context,
+				 skb->data, skb->len, 0);
+	break;
+	case ST21NFCB_EVT_WTX_REQUEST:
+		mod_timer(&info->se_info.bwi_timer, jiffies +
+			  msecs_to_jiffies(info->se_info.wt_timeout));
+	break;
+	}
+
+	kfree_skb(skb);
+	return r;
+}
+
+/*
+ * Returns:
+ * <= 0: driver handled the event, skb consumed
+ *    1: driver does not handle the event, please do standard processing
+ */
+static int st21nfcb_hci_connectivity_event_received(struct nci_dev *ndev,
+						u8 host, u8 event,
+						struct sk_buff *skb)
+{
+	int r = 0;
+
+	pr_debug("connectivity gate event: %x\n", event);
+
+	switch (event) {
+	case ST21NFCB_EVT_CONNECTIVITY:
+	break;
+	case ST21NFCB_EVT_TRANSACTION:
+	break;
+	default:
+		return 1;
+	}
+	kfree_skb(skb);
+	return r;
+}
+
+void st21nfcb_hci_event_received(struct nci_dev *ndev, u8 pipe,
+				 u8 event, struct sk_buff *skb)
+{
+	u8 gate = ndev->hci_dev->pipes[pipe].gate;
+	u8 host = ndev->hci_dev->pipes[pipe].host;
+
+	switch (gate) {
+	case NCI_HCI_ADMIN_GATE:
+		st21nfcb_hci_admin_event_received(ndev, event, skb);
+	break;
+	case ST21NFCB_APDU_READER_GATE:
+		st21nfcb_hci_apdu_reader_event_received(ndev, event, skb);
+	break;
+	case ST21NFCB_CONNECTIVITY_GATE:
+		st21nfcb_hci_connectivity_event_received(ndev, host, event,
+							 skb);
+	break;
+	}
+}
+EXPORT_SYMBOL_GPL(st21nfcb_hci_event_received);
+
+
+void st21nfcb_hci_cmd_received(struct nci_dev *ndev, u8 pipe, u8 cmd,
+			       struct sk_buff *skb)
+{
+	struct st21nfcb_nci_info *info = nci_get_drvdata(ndev);
+	u8 gate = ndev->hci_dev->pipes[pipe].gate;
+
+	pr_debug("cmd: %x\n", cmd);
+
+	switch (cmd) {
+	case NCI_HCI_ANY_OPEN_PIPE:
+		if (gate != ST21NFCB_APDU_READER_GATE &&
+		    ndev->hci_dev->pipes[pipe].host != ST21NFCB_UICC_HOST_ID)
+			ndev->hci_dev->count_pipes++;
+
+		if (ndev->hci_dev->count_pipes ==
+		    ndev->hci_dev->expected_pipes) {
+			del_timer_sync(&info->se_info.se_active_timer);
+			info->se_info.se_active = false;
+			ndev->hci_dev->count_pipes = 0;
+			complete(&info->se_info.req_completion);
+		}
+	break;
+	}
+}
+EXPORT_SYMBOL_GPL(st21nfcb_hci_cmd_received);
+
+/*
+ * Remarks: On some early st21nfcb firmware, nci_nfcee_mode_set(0)
+ * is rejected
+ */
+static int st21nfcb_nci_control_se(struct nci_dev *ndev, u8 se_idx,
+				   u8 state)
+{
+	struct st21nfcb_nci_info *info = nci_get_drvdata(ndev);
+	int r;
+	struct sk_buff *sk_host_list;
+	u8 host_id;
+
+	switch (se_idx) {
+	case ST21NFCB_UICC_HOST_ID:
+		ndev->hci_dev->count_pipes = 0;
+		ndev->hci_dev->expected_pipes = ST21NFCB_SE_COUNT_PIPE_UICC;
+		break;
+	case ST21NFCB_ESE_HOST_ID:
+		ndev->hci_dev->count_pipes = 0;
+		ndev->hci_dev->expected_pipes = ST21NFCB_SE_COUNT_PIPE_EMBEDDED;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/*
+	 * Wait for an EVT_HOT_PLUG in order to
+	 * retrieve a relevant host list.
+	 */
+	reinit_completion(&info->se_info.req_completion);
+	r = nci_nfcee_mode_set(ndev, se_idx, NCI_NFCEE_ENABLE);
+	if (r != NCI_STATUS_OK)
+		return r;
+
+	mod_timer(&info->se_info.se_active_timer, jiffies +
+		msecs_to_jiffies(ST21NFCB_SE_TO_HOT_PLUG));
+	info->se_info.se_active = true;
+
+	/* Ignore return value and check in any case the host_list */
+	wait_for_completion_interruptible(&info->se_info.req_completion);
+
+	/* There might be some "collision" after receiving a HOT_PLUG event
+	 * This may cause the CLF to not answer to the next hci command.
+	 * There is no possible synchronization to prevent this.
+	 * Adding a small delay is the only way to solve the issue.
+	 */
+	usleep_range(3000, 5000);
+
+	r = nci_hci_get_param(ndev, NCI_HCI_ADMIN_GATE,
+			NCI_HCI_ADMIN_PARAM_HOST_LIST, &sk_host_list);
+	if (r != NCI_HCI_ANY_OK)
+		return r;
+
+	host_id = sk_host_list->data[sk_host_list->len - 1];
+	kfree_skb(sk_host_list);
+	if (state == ST21NFCB_SE_MODE_ON && host_id == se_idx)
+		return se_idx;
+	else if (state == ST21NFCB_SE_MODE_OFF && host_id != se_idx)
+		return se_idx;
+
+	return -1;
+}
+
+int st21nfcb_nci_disable_se(struct nci_dev *ndev, u32 se_idx)
+{
+	int r;
+
+	pr_debug("st21nfcb_nci_disable_se\n");
+
+	if (se_idx == NFC_SE_EMBEDDED) {
+		r = nci_hci_send_event(ndev, ST21NFCB_APDU_READER_GATE,
+				ST21NFCB_EVT_SE_END_OF_APDU_TRANSFER, NULL, 0);
+		if (r < 0)
+			return r;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(st21nfcb_nci_disable_se);
+
+int st21nfcb_nci_enable_se(struct nci_dev *ndev, u32 se_idx)
+{
+	int r;
+
+	pr_debug("st21nfcb_nci_enable_se\n");
+
+	if (se_idx == ST21NFCB_HCI_HOST_ID_ESE) {
+		r = nci_hci_send_event(ndev, ST21NFCB_APDU_READER_GATE,
+				ST21NFCB_EVT_SE_SOFT_RESET, NULL, 0);
+		if (r < 0)
+			return r;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(st21nfcb_nci_enable_se);
+
+static int st21nfcb_hci_network_init(struct nci_dev *ndev)
+{
+	struct core_conn_create_dest_spec_params dest_params;
+	struct nci_conn_info    *conn_info;
+	int r, dev_num;
+
+	r = nci_nfcee_discover(ndev, NCI_NFCEE_DISCOVERY_ACTION_ENABLE);
+	if (r != NCI_STATUS_OK)
+		goto exit;
+
+	dest_params.type = NCI_DESTINATION_SPECIFIC_PARAM_NFCEE_TYPE;
+	dest_params.length = sizeof(struct dest_spec_params);
+	dest_params.value.id = ndev->hci_dev->conn_info->id;
+	dest_params.value.protocol = NCI_NFCEE_INTERFACE_HCI_ACCESS;
+	r = nci_core_conn_create(ndev, &dest_params);
+	if (r != NCI_STATUS_OK)
+		goto exit;
+
+	conn_info = ndev->hci_dev->conn_info;
+	if (!conn_info)
+		goto exit;
+
+	memcpy(ndev->hci_dev->init_data.gates, st21nfcb_gates,
+	       sizeof(st21nfcb_gates));
+
+	/*
+	 * Session id must include the driver name + i2c bus addr
+	 * persistent info to discriminate 2 identical chips
+	 */
+	dev_num = find_first_zero_bit(dev_mask, ST21NFCB_NUM_DEVICES);
+	if (dev_num >= ST21NFCB_NUM_DEVICES)
+		return -ENODEV;
+
+	scnprintf(ndev->hci_dev->init_data.session_id,
+		  sizeof(ndev->hci_dev->init_data.session_id),
+		  "%s%2x", "ST21BH", dev_num);
+
+	r = nci_hci_dev_session_init(ndev);
+	if (r != NCI_HCI_ANY_OK)
+		goto exit;
+
+	r = nci_nfcee_mode_set(ndev, ndev->hci_dev->conn_info->id,
+			       NCI_NFCEE_ENABLE);
+	if (r != NCI_STATUS_OK)
+		goto exit;
+
+	return 0;
+
+exit:
+	return r;
+}
+
+int st21nfcb_nci_discover_se(struct nci_dev *ndev)
+{
+	u8 param[2];
+	int r;
+	int se_count = 0;
+
+	pr_debug("st21nfcb_nci_discover_se\n");
+
+	r = st21nfcb_hci_network_init(ndev);
+	if (r != 0)
+		return r;
+
+	param[0] = ST21NFCB_UICC_HOST_ID;
+	param[1] = ST21NFCB_HCI_HOST_ID_ESE;
+	r = nci_hci_set_param(ndev, NCI_HCI_ADMIN_GATE,
+				NCI_HCI_ADMIN_PARAM_WHITELIST,
+				param, sizeof(param));
+	if (r != NCI_HCI_ANY_OK)
+		return r;
+
+	r = st21nfcb_nci_control_se(ndev, ST21NFCB_UICC_HOST_ID,
+				ST21NFCB_SE_MODE_ON);
+	if (r == ST21NFCB_UICC_HOST_ID) {
+		nfc_add_se(ndev->nfc_dev, ST21NFCB_UICC_HOST_ID, NFC_SE_UICC);
+		se_count++;
+	}
+
+	/* Try to enable eSE in order to check availability */
+	r = st21nfcb_nci_control_se(ndev, ST21NFCB_HCI_HOST_ID_ESE,
+				ST21NFCB_SE_MODE_ON);
+	if (r == ST21NFCB_HCI_HOST_ID_ESE) {
+		nfc_add_se(ndev->nfc_dev, ST21NFCB_HCI_HOST_ID_ESE,
+			   NFC_SE_EMBEDDED);
+		se_count++;
+		st21nfcb_se_get_atr(ndev);
+	}
+
+	return !se_count;
+}
+EXPORT_SYMBOL_GPL(st21nfcb_nci_discover_se);
+
+int st21nfcb_nci_se_io(struct nci_dev *ndev, u32 se_idx,
+		       u8 *apdu, size_t apdu_length,
+		       se_io_cb_t cb, void *cb_context)
+{
+	struct st21nfcb_nci_info *info = nci_get_drvdata(ndev);
+
+	pr_debug("\n");
+
+	switch (se_idx) {
+	case ST21NFCB_HCI_HOST_ID_ESE:
+		info->se_info.cb = cb;
+		info->se_info.cb_context = cb_context;
+		mod_timer(&info->se_info.bwi_timer, jiffies +
+			  msecs_to_jiffies(info->se_info.wt_timeout));
+		info->se_info.bwi_active = true;
+		return nci_hci_send_event(ndev, ST21NFCB_APDU_READER_GATE,
+					ST21NFCB_EVT_TRANSMIT_DATA, apdu,
+					apdu_length);
+	default:
+		return -ENODEV;
+	}
+}
+EXPORT_SYMBOL(st21nfcb_nci_se_io);
+
+static void st21nfcb_se_wt_timeout(unsigned long data)
+{
+	/*
+	 * No answer from the secure element
+	 * within the defined timeout.
+	 * Let's send a reset request as recovery procedure.
+	 * According to the situation, we first try to send a software reset
+	 * to the secure element. If the next command is still not
+	 * answering in time, we send to the CLF a secure element hardware
+	 * reset request.
+	 */
+	/* hardware reset managed through VCC_UICC_OUT power supply */
+	u8 param = 0x01;
+	struct st21nfcb_nci_info *info = (struct st21nfcb_nci_info *) data;
+
+	pr_debug("\n");
+
+	info->se_info.bwi_active = false;
+
+	if (!info->se_info.xch_error) {
+		info->se_info.xch_error = true;
+		nci_hci_send_event(info->ndlc->ndev, ST21NFCB_APDU_READER_GATE,
+				ST21NFCB_EVT_SE_SOFT_RESET, NULL, 0);
+	} else {
+		info->se_info.xch_error = false;
+		nci_hci_send_event(info->ndlc->ndev, ST21NFCB_DEVICE_MGNT_GATE,
+				ST21NFCB_EVT_SE_HARD_RESET, &param, 1);
+	}
+	info->se_info.cb(info->se_info.cb_context, NULL, 0, -ETIME);
+}
+
+static void st21nfcb_se_activation_timeout(unsigned long data)
+{
+	struct st21nfcb_nci_info *info = (struct st21nfcb_nci_info *) data;
+
+	pr_debug("\n");
+
+	info->se_info.se_active = false;
+
+	complete(&info->se_info.req_completion);
+}
+
+int st21nfcb_se_init(struct nci_dev *ndev)
+{
+	struct st21nfcb_nci_info *info = nci_get_drvdata(ndev);
+
+	init_completion(&info->se_info.req_completion);
+	/* initialize timers */
+	init_timer(&info->se_info.bwi_timer);
+	info->se_info.bwi_timer.data = (unsigned long)info;
+	info->se_info.bwi_timer.function = st21nfcb_se_wt_timeout;
+	info->se_info.bwi_active = false;
+
+	init_timer(&info->se_info.se_active_timer);
+	info->se_info.se_active_timer.data = (unsigned long)info;
+	info->se_info.se_active_timer.function =
+			st21nfcb_se_activation_timeout;
+	info->se_info.se_active = false;
+
+	info->se_info.xch_error = false;
+
+	info->se_info.wt_timeout =
+		ST21NFCB_BWI_TO_TIMEOUT(ST21NFCB_ATR_DEFAULT_BWI);
+
+	return 0;
+}
+EXPORT_SYMBOL(st21nfcb_se_init);
+
+void st21nfcb_se_deinit(struct nci_dev *ndev)
+{
+	struct st21nfcb_nci_info *info = nci_get_drvdata(ndev);
+
+	if (info->se_info.bwi_active)
+		del_timer_sync(&info->se_info.bwi_timer);
+	if (info->se_info.se_active)
+		del_timer_sync(&info->se_info.se_active_timer);
+
+	info->se_info.se_active = false;
+	info->se_info.bwi_active = false;
+}
+EXPORT_SYMBOL(st21nfcb_se_deinit);
+

drivers/nfc/st21nfcb/st21nfcb_se.h

+/*
+ * NCI based Driver for STMicroelectronics NFC Chip
+ *
+ * Copyright (C) 2014  STMicroelectronics SAS. All rights reserved.
+ *
+ * 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 that 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __LOCAL_ST21NFCB_SE_H_
+#define __LOCAL_ST21NFCB_SE_H_
+
+/*
+ * ref ISO7816-3 chap 8.1. the initial character TS is followed by a
+ * sequence of at most 32 characters.
+ */
+#define ST21NFCB_ESE_MAX_LENGTH		33
+#define ST21NFCB_HCI_HOST_ID_ESE	0xc0
+
+struct st21nfcb_se_info {
+	u8 atr[ST21NFCB_ESE_MAX_LENGTH];
+	struct completion req_completion;
+
+	struct timer_list bwi_timer;
+	int wt_timeout; /* in msecs */
+	bool bwi_active;
+
+	struct timer_list se_active_timer;
+	bool se_active;
+
+	bool xch_error;
+
+	se_io_cb_t cb;
+	void *cb_context;
+};
+
+int st21nfcb_se_init(struct nci_dev *ndev);
+void st21nfcb_se_deinit(struct nci_dev *ndev);
+
+int st21nfcb_nci_discover_se(struct nci_dev *ndev);
+int st21nfcb_nci_enable_se(struct nci_dev *ndev, u32 se_idx);
+int st21nfcb_nci_disable_se(struct nci_dev *ndev, u32 se_idx);
+int st21nfcb_nci_se_io(struct nci_dev *ndev, u32 se_idx,
+					u8 *apdu, size_t apdu_length,
+					se_io_cb_t cb, void *cb_context);
+int st21nfcb_hci_load_session(struct nci_dev *ndev);
+void st21nfcb_hci_event_received(struct nci_dev *ndev, u8 pipe,
+				 u8 event, struct sk_buff *skb);
+void st21nfcb_hci_cmd_received(struct nci_dev *ndev, u8 pipe, u8 cmd,
+			       struct sk_buff *skb);
+
+
+#endif /* __LOCAL_ST21NFCB_NCI_H_ */