diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/nfc/pn533.c | 31 |
1 files changed, 6 insertions, 25 deletions
diff --git a/drivers/nfc/pn533.c b/drivers/nfc/pn533.c index 5fb5b8f1ef3f..5bc0c7cfea9a 100644 --- a/drivers/nfc/pn533.c +++ b/drivers/nfc/pn533.c @@ -94,7 +94,8 @@ MODULE_DEVICE_TABLE(usb, pn533_table); #define PN533_FRAME_SIZE(f) (sizeof(struct pn533_frame) + f->datalen + \ PN533_FRAME_TAIL_LEN) -#define PN533_FRAME_ACK_SIZE (sizeof(struct pn533_frame) + 1) +#define PN533_FRAME_ACK_SIZE 6 /* Preamble (1), SoPC (2), ACK Code (2), + Postamble (1) */ #define PN533_FRAME_CHECKSUM(f) (f->data[f->datalen]) #define PN533_FRAME_POSTAMBLE(f) (f->data[f->datalen + 1]) @@ -402,26 +403,6 @@ static u8 pn533_data_checksum(u8 *data, int datalen) return pn533_checksum(sum); } -/** - * pn533_tx_frame_ack - create a ack frame - * @frame: The frame to be set as ack - * - * Ack is different type of standard frame. As a standard frame, it has - * preamble and start_frame. However the checksum of this frame must fail, - * i.e. datalen + datalen_checksum must NOT be zero. When the checksum test - * fails and datalen = 0 and datalen_checksum = 0xFF, the frame is a ack. - * After datalen_checksum field, the postamble is placed. - */ -static void pn533_tx_frame_ack(struct pn533_frame *frame) -{ - frame->preamble = 0; - frame->start_frame = cpu_to_be16(PN533_SOF); - frame->datalen = 0; - frame->datalen_checksum = 0xFF; - /* data[0] is used as postamble */ - frame->data[0] = 0; -} - static void pn533_tx_frame_init(struct pn533_frame *frame, u8 cmd) { frame->preamble = 0; @@ -612,14 +593,14 @@ static int pn533_submit_urb_for_ack(struct pn533 *dev, gfp_t flags) static int pn533_send_ack(struct pn533 *dev, gfp_t flags) { + u8 ack[PN533_FRAME_ACK_SIZE] = {0x00, 0x00, 0xff, 0x00, 0xff, 0x00}; + /* spec 7.1.1.3: Preamble, SoPC (2), ACK Code (2), Postamble */ int rc; nfc_dev_dbg(&dev->interface->dev, "%s", __func__); - pn533_tx_frame_ack(dev->out_frame); - - dev->out_urb->transfer_buffer = dev->out_frame; - dev->out_urb->transfer_buffer_length = PN533_FRAME_ACK_SIZE; + dev->out_urb->transfer_buffer = ack; + dev->out_urb->transfer_buffer_length = sizeof(ack); rc = usb_submit_urb(dev->out_urb, flags); return rc; |