NFC: st21nfca: Implement load_session HCI hook

This implementation rely on the ST21NFCA_DEVICE_MGNT_GATE and
ST21NFCA_DM_GETINFO proprietary gates commands.

First we are retrieving a pipe list available on the CLF with the
ST21NFCA_DM_GETINFO_PIPE_LIST parameter. A gate<->pipe table match
is done with ST21NFCA_DM_GETINFO_PIPE_INFO for each pipe.
If the pipe is created and open, we fill st21nfca_gates table.
If the pipe is create but closed or is not created we keep the gate
with NFC_HCI_INVALID_PIPE.

Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 116 insertions, 1 deletions

diff --git a/drivers/nfc/st21nfca/st21nfca.c b/drivers/nfc/st21nfca/st21nfca.c
index 69213f37b7ba..9e9b9f1140c8 100644
--- a/drivers/nfc/st21nfca/st21nfca.c
+++ b/drivers/nfc/st21nfca/st21nfca.c
@@ -56,8 +56,18 @@
 
 #define ST21NFCA_DEVICE_MGNT_GATE               0x01
 #define ST21NFCA_DEVICE_MGNT_PIPE               0x02
-#define ST21NFCA_NFC_MODE       0x03    /* NFC_MODE parameter*/
 
+#define ST21NFCA_DM_GETINFO         0x13
+#define ST21NFCA_DM_GETINFO_PIPE_LIST       0x02
+#define ST21NFCA_DM_GETINFO_PIPE_INFO       0x01
+#define ST21NFCA_DM_PIPE_CREATED        0x02
+#define ST21NFCA_DM_PIPE_OPEN           0x04
+#define ST21NFCA_DM_RF_ACTIVE           0x80
+
+#define ST21NFCA_DM_IS_PIPE_OPEN(p) \
+        ((p & 0x0f) == (ST21NFCA_DM_PIPE_CREATED | ST21NFCA_DM_PIPE_OPEN))
+
+#define ST21NFCA_NFC_MODE       0x03    /* NFC_MODE parameter*/
 
 static DECLARE_BITMAP(dev_mask, ST21NFCA_NUM_DEVICES);
 
@@ -72,9 +82,113 @@ static struct nfc_hci_gate st21nfca_gates[] = {
         {ST21NFCA_RF_READER_F_GATE, NFC_HCI_INVALID_PIPE},
         {ST21NFCA_RF_READER_14443_3_A_GATE, NFC_HCI_INVALID_PIPE},
 };
+
+struct st21nfca_pipe_info {
+        u8 pipe_state;
+        u8 src_host_id;
+        u8 src_gate_id;
+        u8 dst_host_id;
+        u8 dst_gate_id;
+};
+
 /* Largest headroom needed for outgoing custom commands */
 #define ST21NFCA_CMDS_HEADROOM  7
 
+static int st21nfca_hci_load_session(struct nfc_hci_dev *hdev)
+{
+        int i, j, r;
+        struct sk_buff *skb_pipe_list, *skb_pipe_info;
+        struct st21nfca_pipe_info *info;
+
+        u8 pipe_list[] = { ST21NFCA_DM_GETINFO_PIPE_LIST,
+                NFC_HCI_TERMINAL_HOST_ID
+        };
+        u8 pipe_info[] = { ST21NFCA_DM_GETINFO_PIPE_INFO,
+                NFC_HCI_TERMINAL_HOST_ID, 0
+        };
+
+        skb_pipe_list = alloc_skb(ST21NFCA_HCI_LLC_MAX_SIZE, GFP_KERNEL);
+        if (!skb_pipe_list) {
+                r = -ENOMEM;
+                goto free_list;
+        }
+
+        skb_pipe_info = alloc_skb(ST21NFCA_HCI_LLC_MAX_SIZE, GFP_KERNEL);
+        if (!skb_pipe_info) {
+                r = -ENOMEM;
+                goto free_info;
+        }
+
+        /* On ST21NFCA device pipes number are dynamics
+         * A maximum of 16 pipes can be created at the same time
+         * 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 ST21NFCA is to:
+         * - get a pipe list for each host.
+         * (eg: NFC_HCI_HOST_CONTROLLER_ID for now).
+         * (TODO Later on UICC HOST and eSE HOST)
+         * - get pipe information
+         * - match retrieved pipe list in st21nfca_gates
+         * ST21NFCA_DEVICE_MGNT_GATE is a proprietary gate
+         * with ST21NFCA_DEVICE_MGNT_PIPE.
+         * Pipe can be closed and need to be open.
+         */
+        r = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,
+                ST21NFCA_DEVICE_MGNT_GATE, ST21NFCA_DEVICE_MGNT_PIPE);
+        if (r < 0)
+                goto free_info;
+
+        /* Get pipe list */
+        r = nfc_hci_send_cmd(hdev, ST21NFCA_DEVICE_MGNT_GATE,
+                        ST21NFCA_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 = nfc_hci_send_cmd(hdev, ST21NFCA_DEVICE_MGNT_GATE,
+                                        ST21NFCA_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)
+                 */
+                info = (struct st21nfca_pipe_info *)
+                                        skb_pipe_info->data;
+                for (j = 0; (j < ARRAY_SIZE(st21nfca_gates)) &&
+                        (st21nfca_gates[j].gate != info->dst_gate_id);
+                        j++)
+                        ;
+
+                if (st21nfca_gates[j].gate == info->dst_gate_id &&
+                        ST21NFCA_DM_IS_PIPE_OPEN(info->pipe_state)) {
+                        st21nfca_gates[j].pipe = pipe_info[2];
+                        hdev->gate2pipe[st21nfca_gates[j].gate] =
+                                st21nfca_gates[j].pipe;
+                }
+        }
+        memcpy(hdev->init_data.gates, st21nfca_gates, sizeof(st21nfca_gates));
+free_info:
+        kfree_skb(skb_pipe_info);
+free_list:
+        kfree_skb(skb_pipe_list);
+        return r;
+}
+
 static int st21nfca_hci_open(struct nfc_hci_dev *hdev)
 {
         struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
@@ -407,6 +521,7 @@ static int st21nfca_hci_check_presence(struct nfc_hci_dev *hdev,
 static struct nfc_hci_ops st21nfca_hci_ops = {
         .open = st21nfca_hci_open,
         .close = st21nfca_hci_close,
+        .load_session = st21nfca_hci_load_session,
         .hci_ready = st21nfca_hci_ready,
         .xmit = st21nfca_hci_xmit,
         .start_poll = st21nfca_hci_start_poll,