NFC: pn533: Split large Tx frames in chunks

On sending large frames (size > 262), we split it in multiple chunks and
send them asynchronously with MI bit.

Signed-off-by: Olivier Guiter <olivier.guiter@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

diff --git a/drivers/nfc/pn533.c b/drivers/nfc/pn533.c
index ae0fa9ee169daf1ec1a2486dc1778cae9721f543..f06ef7c49f8468005c9d4544daf2883d6ac553de 100644 (file)
--- a/drivers/nfc/pn533.c
+++ b/drivers/nfc/pn533.c
@@ -363,12 +363,14 @@ struct pn533 {
        struct urb *in_urb;
 
        struct sk_buff_head resp_q;
+       struct sk_buff_head fragment_skb;
 
        struct workqueue_struct *wq;
        struct work_struct cmd_work;
        struct work_struct cmd_complete_work;
        struct work_struct poll_work;
-       struct work_struct mi_work;
+       struct work_struct mi_rx_work;
+       struct work_struct mi_tx_work;
        struct work_struct tg_work;
        struct work_struct rf_work;
 
@@ -378,6 +380,7 @@ struct pn533 {
        struct mutex cmd_lock;  /* protects cmd queue */
 
        void *cmd_complete_mi_arg;
+       void *cmd_complete_dep_arg;
 
        struct pn533_poll_modulations *poll_mod_active[PN533_POLL_MOD_MAX + 1];
        u8 poll_mod_count;
@@ -2328,7 +2331,15 @@ static int pn533_data_exchange_complete(struct pn533 *dev, void *_arg,
 
        if (mi) {
                dev->cmd_complete_mi_arg = arg;
-               queue_work(dev->wq, &dev->mi_work);
+               queue_work(dev->wq, &dev->mi_rx_work);
+               return -EINPROGRESS;
+       }
+
+       /* Prepare for the next round */
+       if (skb_queue_len(&dev->fragment_skb) > 0) {
+               dev->cmd_complete_dep_arg = arg;
+               queue_work(dev->wq, &dev->mi_tx_work);
+
                return -EINPROGRESS;
        }
 
@@ -2349,6 +2360,50 @@ _error:
        return rc;
 }
 
+/* Split the Tx skb into small chunks */
+static int pn533_fill_fragment_skbs(struct pn533 *dev, struct sk_buff *skb)
+{
+       struct sk_buff *frag;
+       int  frag_size;
+
+       do {
+               /* Remaining size */
+               if (skb->len > PN533_CMD_DATAFRAME_MAXLEN)
+                       frag_size = PN533_CMD_DATAFRAME_MAXLEN;
+               else
+                       frag_size = skb->len;
+
+               /* Allocate and reserve */
+               frag = pn533_alloc_skb(dev, frag_size);
+               if (!frag) {
+                       skb_queue_purge(&dev->fragment_skb);
+                       break;
+               }
+
+               /* Reserve the TG/MI byte */
+               skb_reserve(frag, 1);
+
+               /* MI + TG */
+               if (frag_size  == PN533_CMD_DATAFRAME_MAXLEN)
+                       *skb_push(frag, sizeof(u8)) = (PN533_CMD_MI_MASK | 1);
+               else
+                       *skb_push(frag, sizeof(u8)) =  1; /* TG */
+
+               memcpy(skb_put(frag, frag_size), skb->data, frag_size);
+
+               /* Reduce the size of incoming buffer */
+               skb_pull(skb, frag_size);
+
+               /* Add this to skb_queue */
+               skb_queue_tail(&dev->fragment_skb, frag);
+
+       } while (skb->len > 0);
+
+       dev_kfree_skb(skb);
+
+       return skb_queue_len(&dev->fragment_skb);
+}
+
 static int pn533_transceive(struct nfc_dev *nfc_dev,
                            struct nfc_target *target, struct sk_buff *skb,
                            data_exchange_cb_t cb, void *cb_context)
@@ -2359,15 +2414,6 @@ static int pn533_transceive(struct nfc_dev *nfc_dev,
 
        nfc_dev_dbg(&dev->interface->dev, "%s", __func__);
 
-       if (skb->len > PN533_CMD_DATAEXCH_DATA_MAXLEN) {
-               /* TODO: Implement support to multi-part data exchange */
-               nfc_dev_err(&dev->interface->dev,
-                           "Data length greater than the max allowed: %d",
-                           PN533_CMD_DATAEXCH_DATA_MAXLEN);
-               rc = -ENOSYS;
-               goto error;
-       }
-
        if (!dev->tgt_active_prot) {
                nfc_dev_err(&dev->interface->dev,
                            "Can't exchange data if there is no active target");
@@ -2395,7 +2441,20 @@ static int pn533_transceive(struct nfc_dev *nfc_dev,
                        break;
                }
        default:
-               *skb_push(skb, sizeof(u8)) =  1; /*TG*/
+               /* jumbo frame ? */
+               if (skb->len > PN533_CMD_DATAEXCH_DATA_MAXLEN) {
+                       rc = pn533_fill_fragment_skbs(dev, skb);
+                       if (rc <= 0)
+                               goto error;
+
+                       skb = skb_dequeue(&dev->fragment_skb);
+                       if (!skb) {
+                               rc = -EIO;
+                               goto error;
+                       }
+               } else {
+                       *skb_push(skb, sizeof(u8)) =  1; /* TG */
+               }
 
                rc = pn533_send_data_async(dev, PN533_CMD_IN_DATA_EXCHANGE,
                                           skb, pn533_data_exchange_complete,
@@ -2466,7 +2525,7 @@ static int pn533_tm_send(struct nfc_dev *nfc_dev, struct sk_buff *skb)
 
 static void pn533_wq_mi_recv(struct work_struct *work)
 {
-       struct pn533 *dev = container_of(work, struct pn533, mi_work);
+       struct pn533 *dev = container_of(work, struct pn533, mi_rx_work);
 
        struct sk_buff *skb;
        int rc;
@@ -2514,6 +2573,61 @@ error:
        queue_work(dev->wq, &dev->cmd_work);
 }
 
+static void pn533_wq_mi_send(struct work_struct *work)
+{
+       struct pn533 *dev = container_of(work, struct pn533, mi_tx_work);
+       struct sk_buff *skb;
+       int rc;
+
+       nfc_dev_dbg(&dev->interface->dev, "%s", __func__);
+
+       /* Grab the first skb in the queue */
+       skb = skb_dequeue(&dev->fragment_skb);
+
+       if (skb == NULL) {      /* No more data */
+               /* Reset the queue for future use */
+               skb_queue_head_init(&dev->fragment_skb);
+               goto error;
+       }
+
+       switch (dev->device_type) {
+       case PN533_DEVICE_PASORI:
+               if (dev->tgt_active_prot != NFC_PROTO_FELICA) {
+                       rc = -EIO;
+                       break;
+               }
+
+               rc = pn533_send_cmd_direct_async(dev, PN533_CMD_IN_COMM_THRU,
+                                                skb,
+                                                pn533_data_exchange_complete,
+                                                dev->cmd_complete_dep_arg);
+
+               break;
+
+       default:
+               /* Still some fragments? */
+               rc = pn533_send_cmd_direct_async(dev,PN533_CMD_IN_DATA_EXCHANGE,
+                                                skb,
+                                                pn533_data_exchange_complete,
+                                                dev->cmd_complete_dep_arg);
+
+               break;
+       }
+
+       if (rc == 0) /* success */
+               return;
+
+       nfc_dev_err(&dev->interface->dev,
+                   "Error %d when trying to perform data_exchange", rc);
+
+       dev_kfree_skb(skb);
+       kfree(dev->cmd_complete_dep_arg);
+
+error:
+       pn533_send_ack(dev, GFP_KERNEL);
+       queue_work(dev->wq, &dev->cmd_work);
+}
+
 static int pn533_set_configuration(struct pn533 *dev, u8 cfgitem, u8 *cfgdata,
                                                                u8 cfgdata_len)
 {
@@ -2816,7 +2930,8 @@ static int pn533_probe(struct usb_interface *interface,
 
        INIT_WORK(&dev->cmd_work, pn533_wq_cmd);
        INIT_WORK(&dev->cmd_complete_work, pn533_wq_cmd_complete);
-       INIT_WORK(&dev->mi_work, pn533_wq_mi_recv);
+       INIT_WORK(&dev->mi_rx_work, pn533_wq_mi_recv);
+       INIT_WORK(&dev->mi_tx_work, pn533_wq_mi_send);
        INIT_WORK(&dev->tg_work, pn533_wq_tg_get_data);
        INIT_WORK(&dev->poll_work, pn533_wq_poll);
        INIT_WORK(&dev->rf_work, pn533_wq_rf);
@@ -2829,6 +2944,7 @@ static int pn533_probe(struct usb_interface *interface,
        dev->listen_timer.function = pn533_listen_mode_timer;
 
        skb_queue_head_init(&dev->resp_q);
+       skb_queue_head_init(&dev->fragment_skb);
 
        INIT_LIST_HEAD(&dev->cmd_queue);