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.h

@@ -0,0 +1,61 @@
+/*
+ * 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_ */