NFC: HCI support
This is an implementation of ETSI TS 102 622 specification.
Many NFC chipsets use HCI as the host <-> target protocol on top of a
serial link like i2c.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/nfc/hci/command.c b/net/nfc/hci/command.c
new file mode 100644
index 0000000..8729abf
--- /dev/null
+++ b/net/nfc/hci/command.c
@@ -0,0 +1,354 @@
+/*
+ * Copyright (C) 2012 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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, write to the
+ * Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#define pr_fmt(fmt) "hci: %s: " fmt, __func__
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/module.h>
+
+#include <net/nfc/hci.h>
+
+#include "hci.h"
+
+static int nfc_hci_result_to_errno(u8 result)
+{
+ switch (result) {
+ case NFC_HCI_ANY_OK:
+ return 0;
+ case NFC_HCI_ANY_E_TIMEOUT:
+ return -ETIMEDOUT;
+ default:
+ return -1;
+ }
+}
+
+static void nfc_hci_execute_cb(struct nfc_hci_dev *hdev, u8 result,
+ struct sk_buff *skb, void *cb_data)
+{
+ struct hcp_exec_waiter *hcp_ew = (struct hcp_exec_waiter *)cb_data;
+
+ pr_debug("HCI Cmd completed with HCI result=%d\n", result);
+
+ hcp_ew->exec_result = nfc_hci_result_to_errno(result);
+ if (hcp_ew->exec_result == 0)
+ hcp_ew->result_skb = skb;
+ else
+ kfree_skb(skb);
+ hcp_ew->exec_complete = true;
+
+ wake_up(hcp_ew->wq);
+}
+
+static int nfc_hci_execute_cmd(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
+ const u8 *param, size_t param_len,
+ struct sk_buff **skb)
+{
+ DECLARE_WAIT_QUEUE_HEAD_ONSTACK(ew_wq);
+ struct hcp_exec_waiter hcp_ew;
+ hcp_ew.wq = &ew_wq;
+ hcp_ew.exec_complete = false;
+ hcp_ew.result_skb = NULL;
+
+ pr_debug("through pipe=%d, cmd=%d, plen=%zd\n", pipe, cmd, param_len);
+
+ /* TODO: Define hci cmd execution delay. Should it be the same
+ * for all commands?
+ */
+ hcp_ew.exec_result = nfc_hci_hcp_message_tx(hdev, pipe,
+ NFC_HCI_HCP_COMMAND, cmd,
+ param, param_len,
+ nfc_hci_execute_cb, &hcp_ew,
+ 3000);
+ if (hcp_ew.exec_result < 0)
+ return hcp_ew.exec_result;
+
+ wait_event(ew_wq, hcp_ew.exec_complete == true);
+
+ if (hcp_ew.exec_result == 0) {
+ if (skb)
+ *skb = hcp_ew.result_skb;
+ else
+ kfree_skb(hcp_ew.result_skb);
+ }
+
+ return hcp_ew.exec_result;
+}
+
+int nfc_hci_send_event(struct nfc_hci_dev *hdev, u8 gate, u8 event,
+ const u8 *param, size_t param_len)
+{
+ u8 pipe;
+
+ pr_debug("%d to gate %d\n", event, gate);
+
+ pipe = hdev->gate2pipe[gate];
+ if (pipe == NFC_HCI_INVALID_PIPE)
+ return -EADDRNOTAVAIL;
+
+ return nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_EVENT, event,
+ param, param_len, NULL, NULL, 0);
+}
+EXPORT_SYMBOL(nfc_hci_send_event);
+
+int nfc_hci_send_response(struct nfc_hci_dev *hdev, u8 gate, u8 response,
+ const u8 *param, size_t param_len)
+{
+ u8 pipe;
+
+ pr_debug("\n");
+
+ pipe = hdev->gate2pipe[gate];
+ if (pipe == NFC_HCI_INVALID_PIPE)
+ return -EADDRNOTAVAIL;
+
+ return nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_RESPONSE,
+ response, param, param_len, NULL, NULL,
+ 0);
+}
+EXPORT_SYMBOL(nfc_hci_send_response);
+
+/*
+ * Execute an hci command sent to gate.
+ * skb will contain response data if success. skb can be NULL if you are not
+ * interested by the response.
+ */
+int nfc_hci_send_cmd(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,
+ const u8 *param, size_t param_len, struct sk_buff **skb)
+{
+ u8 pipe;
+
+ pr_debug("\n");
+
+ pipe = hdev->gate2pipe[gate];
+ if (pipe == NFC_HCI_INVALID_PIPE)
+ return -EADDRNOTAVAIL;
+
+ return nfc_hci_execute_cmd(hdev, pipe, cmd, param, param_len, skb);
+}
+EXPORT_SYMBOL(nfc_hci_send_cmd);
+
+int nfc_hci_set_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
+ const u8 *param, size_t param_len)
+{
+ int r;
+ u8 *tmp;
+
+ /* TODO ELa: reg idx must be inserted before param, but we don't want
+ * to ask the caller to do it to keep a simpler API.
+ * For now, just create a new temporary param buffer. This is far from
+ * optimal though, and the plan is to modify APIs to pass idx down to
+ * nfc_hci_hcp_message_tx where the frame is actually built, thereby
+ * eliminating the need for the temp allocation-copy here.
+ */
+
+ pr_debug("idx=%d to gate %d\n", idx, gate);
+
+ tmp = kmalloc(1 + param_len, GFP_KERNEL);
+ if (tmp == NULL)
+ return -ENOMEM;
+
+ *tmp = idx;
+ memcpy(tmp + 1, param, param_len);
+
+ r = nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_SET_PARAMETER,
+ tmp, param_len + 1, NULL);
+
+ kfree(tmp);
+
+ return r;
+}
+EXPORT_SYMBOL(nfc_hci_set_param);
+
+int nfc_hci_get_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
+ struct sk_buff **skb)
+{
+ pr_debug("gate=%d regidx=%d\n", gate, idx);
+
+ return nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_GET_PARAMETER,
+ &idx, 1, skb);
+}
+EXPORT_SYMBOL(nfc_hci_get_param);
+
+static int nfc_hci_open_pipe(struct nfc_hci_dev *hdev, u8 pipe)
+{
+ struct sk_buff *skb;
+ int r;
+
+ pr_debug("pipe=%d\n", pipe);
+
+ r = nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_OPEN_PIPE,
+ NULL, 0, &skb);
+ if (r == 0) {
+ /* dest host other than host controller will send
+ * number of pipes already open on this gate before
+ * execution. The number can be found in skb->data[0]
+ */
+ kfree_skb(skb);
+ }
+
+ return r;
+}
+
+static int nfc_hci_close_pipe(struct nfc_hci_dev *hdev, u8 pipe)
+{
+ pr_debug("\n");
+
+ return nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_CLOSE_PIPE,
+ NULL, 0, NULL);
+}
+
+static u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,
+ u8 dest_gate, int *result)
+{
+ struct sk_buff *skb;
+ struct hci_create_pipe_params params;
+ struct hci_create_pipe_resp *resp;
+ u8 pipe;
+
+ pr_debug("gate=%d\n", dest_gate);
+
+ params.src_gate = NFC_HCI_ADMIN_GATE;
+ params.dest_host = dest_host;
+ params.dest_gate = dest_gate;
+
+ *result = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
+ NFC_HCI_ADM_CREATE_PIPE,
+ (u8 *) ¶ms, sizeof(params), &skb);
+ if (*result == 0) {
+ resp = (struct hci_create_pipe_resp *)skb->data;
+ pipe = resp->pipe;
+ kfree_skb(skb);
+
+ pr_debug("pipe created=%d\n", pipe);
+
+ return pipe;
+ } else
+ return NFC_HCI_INVALID_PIPE;
+}
+
+static int nfc_hci_delete_pipe(struct nfc_hci_dev *hdev, u8 pipe)
+{
+ pr_debug("\n");
+
+ return nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
+ NFC_HCI_ADM_DELETE_PIPE, &pipe, 1, NULL);
+}
+
+static int nfc_hci_clear_all_pipes(struct nfc_hci_dev *hdev)
+{
+ int r;
+
+ u8 param[2];
+
+ /* TODO: Find out what the identity reference data is
+ * and fill param with it. HCI spec 6.1.3.5 */
+
+ pr_debug("\n");
+
+ r = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
+ NFC_HCI_ADM_CLEAR_ALL_PIPE, param, 2, NULL);
+
+ return 0;
+}
+
+int nfc_hci_disconnect_gate(struct nfc_hci_dev *hdev, u8 gate)
+{
+ int r;
+ u8 pipe = hdev->gate2pipe[gate];
+
+ pr_debug("\n");
+
+ if (pipe == NFC_HCI_INVALID_PIPE)
+ return -EADDRNOTAVAIL;
+
+ r = nfc_hci_close_pipe(hdev, pipe);
+ if (r < 0)
+ return r;
+
+ if (pipe != NFC_HCI_LINK_MGMT_PIPE && pipe != NFC_HCI_ADMIN_PIPE) {
+ r = nfc_hci_delete_pipe(hdev, pipe);
+ if (r < 0)
+ return r;
+ }
+
+ hdev->gate2pipe[gate] = NFC_HCI_INVALID_PIPE;
+
+ return 0;
+}
+EXPORT_SYMBOL(nfc_hci_disconnect_gate);
+
+int nfc_hci_disconnect_all_gates(struct nfc_hci_dev *hdev)
+{
+ int r;
+
+ pr_debug("\n");
+
+ r = nfc_hci_clear_all_pipes(hdev);
+ if (r < 0)
+ return r;
+
+ memset(hdev->gate2pipe, NFC_HCI_INVALID_PIPE, sizeof(hdev->gate2pipe));
+
+ return 0;
+}
+EXPORT_SYMBOL(nfc_hci_disconnect_all_gates);
+
+int nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate)
+{
+ u8 pipe = NFC_HCI_INVALID_PIPE;
+ bool pipe_created = false;
+ int r;
+
+ pr_debug("\n");
+
+ if (hdev->gate2pipe[dest_gate] != NFC_HCI_INVALID_PIPE)
+ return -EADDRINUSE;
+
+ switch (dest_gate) {
+ case NFC_HCI_LINK_MGMT_GATE:
+ pipe = NFC_HCI_LINK_MGMT_PIPE;
+ break;
+ case NFC_HCI_ADMIN_GATE:
+ pipe = NFC_HCI_ADMIN_PIPE;
+ break;
+ default:
+ pipe = nfc_hci_create_pipe(hdev, dest_host, dest_gate, &r);
+ if (pipe == NFC_HCI_INVALID_PIPE)
+ return r;
+ pipe_created = true;
+ break;
+ }
+
+ r = nfc_hci_open_pipe(hdev, pipe);
+ if (r < 0) {
+ if (pipe_created)
+ if (nfc_hci_delete_pipe(hdev, pipe) < 0) {
+ /* TODO: Cannot clean by deleting pipe...
+ * -> inconsistent state */
+ }
+ return r;
+ }
+
+ hdev->gate2pipe[dest_gate] = pipe;
+
+ return 0;
+}
+EXPORT_SYMBOL(nfc_hci_connect_gate);