NFC: pn533: Add a new pn533_send_sync iface
It is intended to replace pn533_send_cmd_frame_sync() iface which
requires from the caller to create complete frame.
The new function constructs a complete frame itself and sends it out
in sync manner. This way frame logic is hidden from the caller.
pn533_send_cmd_sync() returns ERR_PTR in case of an error or a pointer
to valid response sk_buff otherwise. The pointer must be freed by the
caller when it's been consumed.
Signed-off-by: Waldemar Rymarkiewicz <waldemar.rymarkiewicz@tieto.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/nfc/pn533.c b/drivers/nfc/pn533.c
index 0e9bf9d..94c88bb 100644
--- a/drivers/nfc/pn533.c
+++ b/drivers/nfc/pn533.c
@@ -945,6 +945,7 @@
struct pn533_sync_cmd_response {
int rc;
+ struct sk_buff *resp;
struct completion done;
};
@@ -965,6 +966,58 @@
return 0;
}
+static int pn533_send_sync_complete(struct pn533 *dev, void *_arg,
+ struct sk_buff *resp)
+{
+ struct pn533_sync_cmd_response *arg = _arg;
+
+ nfc_dev_dbg(&dev->interface->dev, "%s", __func__);
+
+ arg->resp = resp;
+ complete(&arg->done);
+
+ return 0;
+}
+
+/* pn533_send_cmd_sync
+ *
+ * Please note the req parameter is freed inside the function to
+ * limit a number of return value interpretations by the caller.
+ *
+ * 1. negative in case of error during TX path -> req should be freed
+ *
+ * 2. negative in case of error during RX path -> req should not be freed
+ * as it's been already freed at the begining of RX path by
+ * async_complete_cb.
+ *
+ * 3. valid pointer in case of succesfult RX path
+ *
+ * A caller has to check a return value with IS_ERR macro. If the test pass,
+ * the returned pointer is valid.
+ *
+ * */
+static struct sk_buff *pn533_send_cmd_sync(struct pn533 *dev, u8 cmd_code,
+ struct sk_buff *req)
+{
+ int rc;
+ struct pn533_sync_cmd_response arg;
+
+ nfc_dev_dbg(&dev->interface->dev, "%s", __func__);
+
+ init_completion(&arg.done);
+
+ rc = pn533_send_cmd_async(dev, cmd_code, req,
+ pn533_send_sync_complete, &arg);
+ if (rc) {
+ dev_kfree_skb(req);
+ return ERR_PTR(rc);
+ }
+
+ wait_for_completion(&arg.done);
+
+ return arg.resp;
+}
+
static int pn533_send_cmd_frame_sync(struct pn533 *dev,
struct pn533_frame *out_frame,
struct pn533_frame *in_frame,
@@ -2432,7 +2485,7 @@
rc = pn533_send_cmd_frame_sync(dev, dev->out_frame, dev->in_frame,
PN533_NORMAL_FRAME_MAX_LEN);
- return rc;
+ return 0;
}
static struct nfc_ops pn533_nfc_ops = {