From 6ff73fd239ff5d6f1ebfe5b5f7f560d9fad7d749 Mon Sep 17 00:00:00 2001 From: Samuel Ortiz Date: Tue, 10 Apr 2012 19:43:18 +0200 Subject: NFC: pn533 Rx chaining support When buffers on the receiption path exceed 262 bytes, the pn533 uses a chaining mechanism where the initiator has to send NULL data frames to fetch the remaining frames. We do that from a workqueue context while holding the cmd lock. Once the MI bit is gone, we aggregate the queued received skbs. Signed-off-by: Samuel Ortiz Signed-off-by: John W. Linville --- drivers/nfc/pn533.c | 144 ++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 128 insertions(+), 16 deletions(-) (limited to 'drivers/nfc') diff --git a/drivers/nfc/pn533.c b/drivers/nfc/pn533.c index f2ee06f059f9..e6ec16d92e65 100644 --- a/drivers/nfc/pn533.c +++ b/drivers/nfc/pn533.c @@ -266,8 +266,11 @@ struct pn533 { int in_maxlen; struct pn533_frame *in_frame; + struct sk_buff_head resp_q; + struct workqueue_struct *wq; struct work_struct cmd_work; + struct work_struct mi_work; struct pn533_frame *wq_in_frame; int wq_in_error; @@ -1256,6 +1259,8 @@ static void pn533_deactivate_target(struct nfc_dev *nfc_dev, u32 target_idx) dev->tgt_active_prot = 0; + skb_queue_purge(&dev->resp_q); + pn533_tx_frame_init(dev->out_frame, PN533_CMD_IN_RELEASE); tg = 1; @@ -1454,11 +1459,49 @@ struct pn533_data_exchange_arg { void *cb_context; }; +static struct sk_buff *pn533_build_response(struct pn533 *dev) +{ + struct sk_buff *skb, *tmp, *t; + unsigned int skb_len = 0, tmp_len = 0; + + nfc_dev_dbg(&dev->interface->dev, "%s\n", __func__); + + if (skb_queue_empty(&dev->resp_q)) + return NULL; + + if (skb_queue_len(&dev->resp_q) == 1) { + skb = skb_dequeue(&dev->resp_q); + goto out; + } + + skb_queue_walk_safe(&dev->resp_q, tmp, t) + skb_len += tmp->len; + + nfc_dev_dbg(&dev->interface->dev, "%s total length %d\n", + __func__, skb_len); + + skb = alloc_skb(skb_len, GFP_KERNEL); + if (skb == NULL) + goto out; + + skb_put(skb, skb_len); + + skb_queue_walk_safe(&dev->resp_q, tmp, t) { + memcpy(skb->data + tmp_len, tmp->data, tmp->len); + tmp_len += tmp->len; + } + +out: + skb_queue_purge(&dev->resp_q); + + return skb; +} + static int pn533_data_exchange_complete(struct pn533 *dev, void *_arg, u8 *params, int params_len) { struct pn533_data_exchange_arg *arg = _arg; - struct sk_buff *skb_resp = arg->skb_resp; + struct sk_buff *skb = NULL, *skb_resp = arg->skb_resp; struct pn533_frame *in_frame = (struct pn533_frame *) skb_resp->data; int err = 0; u8 status; @@ -1466,15 +1509,13 @@ static int pn533_data_exchange_complete(struct pn533 *dev, void *_arg, nfc_dev_dbg(&dev->interface->dev, "%s", __func__); - dev_kfree_skb_irq(arg->skb_out); + dev_kfree_skb(arg->skb_out); if (params_len < 0) { /* error */ err = params_len; goto error; } - skb_put(skb_resp, PN533_FRAME_SIZE(in_frame)); - status = params[0]; cmd_ret = status & PN533_CMD_RET_MASK; @@ -1485,25 +1526,27 @@ static int pn533_data_exchange_complete(struct pn533 *dev, void *_arg, goto error; } + skb_put(skb_resp, PN533_FRAME_SIZE(in_frame)); + skb_pull(skb_resp, PN533_CMD_DATAEXCH_HEAD_LEN); + skb_trim(skb_resp, skb_resp->len - PN533_FRAME_TAIL_SIZE); + skb_queue_tail(&dev->resp_q, skb_resp); + if (status & PN533_CMD_MI_MASK) { - /* TODO: Implement support to multi-part data exchange */ - nfc_dev_err(&dev->interface->dev, "Multi-part message not yet" - " supported"); - /* Prevent the other messages from controller */ - pn533_send_ack(dev, GFP_ATOMIC); - err = -ENOSYS; - goto error; + queue_work(dev->wq, &dev->mi_work); + return -EINPROGRESS; } - skb_pull(skb_resp, PN533_CMD_DATAEXCH_HEAD_LEN); - skb_trim(skb_resp, skb_resp->len - PN533_FRAME_TAIL_SIZE); + skb = pn533_build_response(dev); + if (skb == NULL) + goto error; - arg->cb(arg->cb_context, skb_resp, 0); + arg->cb(arg->cb_context, skb, 0); kfree(arg); return 0; error: - dev_kfree_skb_irq(skb_resp); + skb_queue_purge(&dev->resp_q); + dev_kfree_skb(skb_resp); arg->cb(arg->cb_context, NULL, err); kfree(arg); return 0; @@ -1578,6 +1621,68 @@ error: return rc; } +static void pn533_wq_mi_recv(struct work_struct *work) +{ + struct pn533 *dev = container_of(work, struct pn533, mi_work); + struct sk_buff *skb_cmd; + struct pn533_data_exchange_arg *arg = dev->cmd_complete_arg; + struct pn533_frame *out_frame, *in_frame; + struct sk_buff *skb_resp; + int skb_resp_len; + int rc; + + nfc_dev_dbg(&dev->interface->dev, "%s", __func__); + + /* This is a zero payload size skb */ + skb_cmd = alloc_skb(PN533_CMD_DATAEXCH_HEAD_LEN + PN533_FRAME_TAIL_SIZE, + GFP_KERNEL); + if (skb_cmd == NULL) + goto error_cmd; + + skb_reserve(skb_cmd, PN533_CMD_DATAEXCH_HEAD_LEN); + + rc = pn533_data_exchange_tx_frame(dev, skb_cmd); + if (rc) + goto error_frame; + + skb_resp_len = PN533_CMD_DATAEXCH_HEAD_LEN + + PN533_CMD_DATAEXCH_DATA_MAXLEN + + PN533_FRAME_TAIL_SIZE; + skb_resp = alloc_skb(skb_resp_len, GFP_KERNEL); + if (!skb_resp) { + rc = -ENOMEM; + goto error_frame; + } + + in_frame = (struct pn533_frame *) skb_resp->data; + out_frame = (struct pn533_frame *) skb_cmd->data; + + arg->skb_resp = skb_resp; + arg->skb_out = skb_cmd; + + rc = __pn533_send_cmd_frame_async(dev, out_frame, in_frame, + skb_resp_len, + pn533_data_exchange_complete, + dev->cmd_complete_arg, GFP_KERNEL); + if (!rc) + return; + + nfc_dev_err(&dev->interface->dev, "Error %d when trying to" + " perform data_exchange", rc); + + kfree_skb(skb_resp); + +error_frame: + kfree_skb(skb_cmd); + +error_cmd: + pn533_send_ack(dev, GFP_KERNEL); + + kfree(arg); + + up(&dev->cmd_lock); +} + static int pn533_set_configuration(struct pn533 *dev, u8 cfgitem, u8 *cfgdata, u8 cfgdata_len) { @@ -1676,10 +1781,15 @@ static int pn533_probe(struct usb_interface *interface, pn533_send_complete, dev); INIT_WORK(&dev->cmd_work, pn533_wq_cmd_complete); - dev->wq = create_singlethread_workqueue("pn533"); + INIT_WORK(&dev->mi_work, pn533_wq_mi_recv); + dev->wq = alloc_workqueue("pn533", + WQ_NON_REENTRANT | WQ_UNBOUND | WQ_MEM_RECLAIM, + 1); if (dev->wq == NULL) goto error; + skb_queue_head_init(&dev->resp_q); + usb_set_intfdata(interface, dev); pn533_tx_frame_init(dev->out_frame, PN533_CMD_GET_FIRMWARE_VERSION); @@ -1756,6 +1866,8 @@ static void pn533_disconnect(struct usb_interface *interface) destroy_workqueue(dev->wq); + skb_queue_purge(&dev->resp_q); + kfree(dev->in_frame); usb_free_urb(dev->in_urb); kfree(dev->out_frame); -- cgit v1.2.3-59-g8ed1b