NFC: Implement pn533 target mode polling loop

We only want to support p2p target mode for now, no host card emulation.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 104 insertions, 5 deletions

diff --git a/drivers/nfc/pn533.c b/drivers/nfc/pn533.c
index 38a523c62132..605a08a62e45 100644
--- a/drivers/nfc/pn533.c
+++ b/drivers/nfc/pn533.c
@@ -74,6 +74,8 @@ MODULE_DEVICE_TABLE(usb, pn533_table);
 #define PN533_CMD_IN_RELEASE 0x52
 #define PN533_CMD_IN_JUMP_FOR_DEP 0x56
 
+#define PN533_CMD_TG_INIT_AS_TARGET 0x8c
+
 #define PN533_CMD_RESPONSE(cmd) (cmd + 1)
 
 /* PN533 Return codes */
@@ -253,6 +255,25 @@ struct pn533_cmd_jump_dep_response {
         u8 gt[];
 } __packed;
 
+
+/* PN533_TG_INIT_AS_TARGET */
+#define PN533_INIT_TARGET_PASSIVE 0x1
+#define PN533_INIT_TARGET_DEP 0x2
+
+struct pn533_cmd_init_target {
+        u8 mode;
+        u8 mifare[6];
+        u8 felica[18];
+        u8 nfcid3[10];
+        u8 gb_len;
+        u8 gb[];
+} __packed;
+
+struct pn533_cmd_init_target_response {
+        u8 mode;
+        u8 cmd[];
+} __packed;
+
 struct pn533 {
         struct usb_device *udev;
         struct usb_interface *interface;
@@ -1078,11 +1099,88 @@ stop_poll:
         return 0;
 }
 
-static int pn533_init_target(struct nfc_dev *nfc_dev, u32 protocols)
+static int pn533_init_target_frame(struct pn533_frame *frame,
+                                   u8 *gb, size_t gb_len)
 {
+        struct pn533_cmd_init_target *cmd;
+        size_t cmd_len;
+
+        cmd_len = sizeof(struct pn533_cmd_init_target) + gb_len + 1;
+        cmd = kzalloc(cmd_len, GFP_KERNEL);
+        if (cmd == NULL)
+                return -ENOMEM;
+
+        pn533_tx_frame_init(frame, PN533_CMD_TG_INIT_AS_TARGET);
+
+        /* DEP support only */
+        cmd->mode |= PN533_INIT_TARGET_DEP;
+        get_random_bytes(cmd->nfcid3, 10);
+        cmd->gb_len = gb_len;
+        memcpy(cmd->gb, gb, gb_len);
+        /* Len Tk */
+        cmd->gb[gb_len] = 0;
+
+        memcpy(PN533_FRAME_CMD_PARAMS_PTR(frame), cmd, cmd_len);
+        frame->datalen += cmd_len;
+
+        pn533_tx_frame_finish(frame);
+
         return 0;
 }
 
+static int pn533_init_target_complete(struct pn533 *dev, void *arg,
+                                      u8 *params, int params_len)
+{
+        struct pn533_cmd_init_target_response *resp;
+
+        nfc_dev_dbg(&dev->interface->dev, "%s", __func__);
+
+        if (params_len < 0) {
+                nfc_dev_err(&dev->interface->dev,
+                            "Error %d when starting as a target",
+                            params_len);
+
+                return params_len;
+        }
+
+        resp = (struct pn533_cmd_init_target_response *) params;
+
+        nfc_dev_dbg(&dev->interface->dev, "Target mode 0x%x\n", resp->mode);
+
+        return 0;
+}
+
+static int pn533_init_target(struct nfc_dev *nfc_dev, u32 protocols)
+{
+        struct pn533 *dev = nfc_get_drvdata(nfc_dev);
+        u8 *gb;
+        size_t gb_len;
+        int rc;
+
+        pn533_poll_reset_mod_list(dev);
+
+        gb = nfc_get_local_general_bytes(nfc_dev, &gb_len);
+        if (gb == NULL)
+                return -ENOMEM;
+
+        rc = pn533_init_target_frame(dev->out_frame, gb, gb_len);
+        if (rc < 0)
+                return rc;
+
+        rc = pn533_send_cmd_frame_async(dev, dev->out_frame, dev->in_frame,
+                                        dev->in_maxlen,
+                                        pn533_init_target_complete,
+                                        NULL, GFP_KERNEL);
+
+        if (rc)
+                nfc_dev_err(&dev->interface->dev,
+                            "Error %d when trying to initiate as a target", rc);
+
+        dev->poll_mod_count++;
+
+        return rc;
+}
+
 static int pn533_start_im_poll(struct nfc_dev *nfc_dev, u32 protocols)
 {
         struct pn533 *dev = nfc_get_drvdata(nfc_dev);
@@ -1146,12 +1244,13 @@ static int pn533_start_poll(struct nfc_dev *nfc_dev,
                 return -EBUSY;
         }
 
-        if (!tm_protocols)
+        if (im_protocols)
                 return pn533_start_im_poll(nfc_dev, im_protocols);
-        else if (!im_protocols)
+
+        if (tm_protocols)
                 return pn533_init_target(nfc_dev, tm_protocols);
-        else
-                return -EINVAL;
+
+        return -EINVAL;
 }
 
 static void pn533_stop_poll(struct nfc_dev *nfc_dev)