NFC: nci: Add HCI over NCI protocol support

According to the NCI specification, one can use HCI over NCI
to talk with specific NFCEE. The HCI network is viewed as one
logical NFCEE.
This is needed to support secure element running HCI only
firmwares embedded on an NCI capable chipset, like e.g. the
st21nfcb.
There is some duplication between this piece of code and the
HCI core code, but the latter would need to be abstracted even
more to be able to use NCI as a logical transport for HCP packets.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

include/net/nfc/nci_core.h

@@ -78,6 +78,11 @@ struct nci_ops {
 	int   (*se_io)(struct nci_dev *ndev, u32 se_idx,
 				u8 *apdu, size_t apdu_length,
 				se_io_cb_t cb, void *cb_context);
+	int   (*hci_load_session)(struct nci_dev *ndev);
+	void  (*hci_event_received)(struct nci_dev *ndev, u8 pipe, u8 event,
+				    struct sk_buff *skb);
+	void  (*hci_cmd_received)(struct nci_dev *ndev, u8 pipe, u8 cmd,
+				  struct sk_buff *skb);
 };
 
 #define NCI_MAX_SUPPORTED_RF_INTERFACES		4
@@ -102,10 +107,77 @@ struct nci_conn_info {
 
 #define NCI_INVALID_CONN_ID 0x80
 
+#define NCI_HCI_ANY_OPEN_PIPE      0x03
+
+/* Gates */
+#define NCI_HCI_ADMIN_GATE         0x00
+#define NCI_HCI_LINK_MGMT_GATE     0x06
+
+/* Pipes */
+#define NCI_HCI_LINK_MGMT_PIPE             0x00
+#define NCI_HCI_ADMIN_PIPE                 0x01
+
+/* Generic responses */
+#define NCI_HCI_ANY_OK                     0x00
+#define NCI_HCI_ANY_E_NOT_CONNECTED        0x01
+#define NCI_HCI_ANY_E_CMD_PAR_UNKNOWN      0x02
+#define NCI_HCI_ANY_E_NOK                  0x03
+#define NCI_HCI_ANY_E_PIPES_FULL           0x04
+#define NCI_HCI_ANY_E_REG_PAR_UNKNOWN      0x05
+#define NCI_HCI_ANY_E_PIPE_NOT_OPENED      0x06
+#define NCI_HCI_ANY_E_CMD_NOT_SUPPORTED    0x07
+#define NCI_HCI_ANY_E_INHIBITED            0x08
+#define NCI_HCI_ANY_E_TIMEOUT              0x09
+#define NCI_HCI_ANY_E_REG_ACCESS_DENIED    0x0a
+#define NCI_HCI_ANY_E_PIPE_ACCESS_DENIED   0x0b
+
+#define NCI_HCI_DO_NOT_OPEN_PIPE           0x81
+#define NCI_HCI_INVALID_PIPE               0x80
+#define NCI_HCI_INVALID_GATE               0xFF
+#define NCI_HCI_INVALID_HOST               0x80
+
+#define NCI_HCI_MAX_CUSTOM_GATES   50
+#define NCI_HCI_MAX_PIPES          127
+
+struct nci_hci_gate {
+	u8 gate;
+	u8 pipe;
+	u8 dest_host;
+} __packed;
+
+struct nci_hci_pipe {
+	u8 gate;
+	u8 host;
+} __packed;
+
+struct nci_hci_init_data {
+	u8 gate_count;
+	struct nci_hci_gate gates[NCI_HCI_MAX_CUSTOM_GATES];
+	char session_id[9];
+};
+
+#define NCI_HCI_MAX_GATES          256
+
+struct nci_hci_dev {
+	struct nci_dev *ndev;
+	struct nci_conn_info *conn_info;
+
+	struct nci_hci_init_data init_data;
+	struct nci_hci_pipe pipes[NCI_HCI_MAX_PIPES];
+	u8 gate2pipe[NCI_HCI_MAX_GATES];
+	int expected_pipes;
+	int count_pipes;
+
+	struct sk_buff_head rx_hcp_frags;
+	struct work_struct msg_rx_work;
+	struct sk_buff_head msg_rx_queue;
+};
+
 /* NCI Core structures */
 struct nci_dev {
 	struct nfc_dev		*nfc_dev;
 	struct nci_ops		*ops;
+	struct nci_hci_dev	*hci_dev;
 
 	int			tx_headroom;
 	int			tx_tailroom;
@@ -181,6 +253,10 @@ struct nci_dev *nci_allocate_device(struct nci_ops *ops,
 void nci_free_device(struct nci_dev *ndev);
 int nci_register_device(struct nci_dev *ndev);
 void nci_unregister_device(struct nci_dev *ndev);
+int nci_request(struct nci_dev *ndev,
+		void (*req)(struct nci_dev *ndev,
+			    unsigned long opt),
+		unsigned long opt, __u32 timeout);
 int nci_recv_frame(struct nci_dev *ndev, struct sk_buff *skb);
 int nci_set_config(struct nci_dev *ndev, __u8 id, size_t len, __u8 *val);
 
@@ -190,6 +266,21 @@ int nci_core_conn_create(struct nci_dev *ndev,
 			 struct core_conn_create_dest_spec_params *params);
 int nci_core_conn_close(struct nci_dev *ndev, u8 conn_id);
 
+struct nci_hci_dev *nci_hci_allocate(struct nci_dev *ndev);
+int nci_hci_send_event(struct nci_dev *ndev, u8 gate, u8 event,
+		       const u8 *param, size_t param_len);
+int nci_hci_send_cmd(struct nci_dev *ndev, u8 gate,
+		     u8 cmd, const u8 *param, size_t param_len,
+		     struct sk_buff **skb);
+int nci_hci_open_pipe(struct nci_dev *ndev, u8 pipe);
+int nci_hci_connect_gate(struct nci_dev *ndev, u8 dest_host,
+			 u8 dest_gate, u8 pipe);
+int nci_hci_set_param(struct nci_dev *ndev, u8 gate, u8 idx,
+		      const u8 *param, size_t param_len);
+int nci_hci_get_param(struct nci_dev *ndev, u8 gate, u8 idx,
+		      struct sk_buff **skb);
+int nci_hci_dev_session_init(struct nci_dev *ndev);
+
 static inline struct sk_buff *nci_skb_alloc(struct nci_dev *ndev,
 					    unsigned int len,
 					    gfp_t how)
@@ -225,6 +316,8 @@ int nci_send_cmd(struct nci_dev *ndev, __u16 opcode, __u8 plen, void *payload);
 int nci_send_data(struct nci_dev *ndev, __u8 conn_id, struct sk_buff *skb);
 void nci_data_exchange_complete(struct nci_dev *ndev, struct sk_buff *skb,
 				__u8 conn_id, int err);
+void nci_hci_data_received_cb(void *context, struct sk_buff *skb, int err);
+
 void nci_clear_target_list(struct nci_dev *ndev);
 
 /* ----- NCI requests ----- */

net/nfc/nci/Makefile

@@ -4,6 +4,6 @@
 
 obj-$(CONFIG_NFC_NCI) += nci.o
 
-nci-objs := core.o data.o lib.o ntf.o rsp.o
+nci-objs := core.o data.o lib.o ntf.o rsp.o hci.o
 
 nci-$(CONFIG_NFC_NCI_SPI) += spi.o

net/nfc/nci/core.c

@@ -122,7 +122,7 @@ static int __nci_request(struct nci_dev *ndev,
 	return rc;
 }
 
-static inline int nci_request(struct nci_dev *ndev,
+inline int nci_request(struct nci_dev *ndev,
 		       void (*req)(struct nci_dev *ndev,
 				   unsigned long opt),
 		       unsigned long opt, __u32 timeout)
@@ -901,7 +901,6 @@ static struct nfc_ops nci_nfc_ops = {
 };
 
 /* ---- Interface to NCI drivers ---- */
-
 /**
  * nci_allocate_device - allocate a new nci device
  *
@@ -936,13 +935,20 @@ struct nci_dev *nci_allocate_device(struct nci_ops *ops,
 					    tx_headroom + NCI_DATA_HDR_SIZE,
 					    tx_tailroom);
 	if (!ndev->nfc_dev)
-		goto free_exit;
+		goto free_nci;
+
+	ndev->hci_dev = nci_hci_allocate(ndev);
+	if (!ndev->hci_dev)
+		goto free_nfc;
 
 	nfc_set_drvdata(ndev->nfc_dev, ndev);
 
 	return ndev;
 
-free_exit:
+free_nfc:
+	kfree(ndev->nfc_dev);
+
+free_nci:
 	kfree(ndev);
 	return NULL;
 }

net/nfc/nci/ntf.c

@@ -723,8 +723,14 @@ static void nci_nfcee_discover_ntf_packet(struct nci_dev *ndev,
 
 	pr_debug("\n");
 
+	/* NFCForum NCI 9.2.1 HCI Network Specific Handling
+	 * If the NFCC supports the HCI Network, it SHALL return one,
+	 * and only one, NFCEE_DISCOVER_NTF with a Protocol type of
+	 * “HCI Access”, even if the HCI Network contains multiple NFCEEs.
+	 */
+	if (!ndev->hci_dev->conn_info) {
 		conn_info = devm_kzalloc(&ndev->nfc_dev->dev,
-				 sizeof(struct nci_conn_info), GFP_KERNEL);
+					 sizeof(*conn_info), GFP_KERNEL);
 		if (!conn_info) {
 			status = NCI_STATUS_REJECTED;
 			goto exit;
@@ -733,9 +739,15 @@ static void nci_nfcee_discover_ntf_packet(struct nci_dev *ndev,
 		conn_info->id = nfcee_ntf->nfcee_id;
 		conn_info->conn_id = NCI_INVALID_CONN_ID;
 
+		conn_info->data_exchange_cb = nci_hci_data_received_cb;
+		conn_info->data_exchange_cb_context = ndev;
+
 		INIT_LIST_HEAD(&conn_info->list);
 		list_add(&conn_info->list, &ndev->conn_info_list);
 
+		ndev->hci_dev->conn_info = conn_info;
+	}
+
 exit:
 	nci_req_complete(ndev, status);
 }