diff options
Diffstat (limited to 'drivers/bluetooth')
| -rw-r--r-- | drivers/bluetooth/hci_h5.c | 230 |
1 files changed, 222 insertions, 8 deletions
diff --git a/drivers/bluetooth/hci_h5.c b/drivers/bluetooth/hci_h5.c index ae1bd32d8ef9..ddf7ebbaaef3 100644 --- a/drivers/bluetooth/hci_h5.c +++ b/drivers/bluetooth/hci_h5.c @@ -34,20 +34,37 @@ #define H5_ACK_TIMEOUT msecs_to_jiffies(250) +/* + * Maximum Three-wire packet: + * 4 byte header + max value for 12-bit length + 2 bytes for CRC + */ +#define H5_MAX_LEN (4 + 0xfff + 2) + +#define SLIP_DELIMITER 0xc0 +#define SLIP_ESC 0xdb +#define SLIP_ESC_DELIM 0xdc +#define SLIP_ESC_ESC 0xdd + struct h5 { - struct sk_buff_head unack; /* Unack'ed packets queue */ - struct sk_buff_head rel; /* Reliable packets queue */ - struct sk_buff_head unrel; /* Unreliable packets queue */ + struct sk_buff_head unack; /* Unack'ed packets queue */ + struct sk_buff_head rel; /* Reliable packets queue */ + struct sk_buff_head unrel; /* Unreliable packets queue */ - struct sk_buff *rx_skb; + struct sk_buff *rx_skb; /* Receive buffer */ + size_t rx_pending; /* Expecting more bytes */ + bool rx_esc; /* SLIP escape mode */ - struct timer_list timer; /* Retransmission timer */ + int (*rx_func) (struct hci_uart *hu, u8 c); - bool txack_req; + struct timer_list timer; /* Retransmission timer */ - u8 msgq_txseq; + bool txack_req; + + u8 msgq_txseq; }; +static void h5_reset_rx(struct h5 *h5); + static void h5_timed_event(unsigned long arg) { struct hci_uart *hu = (struct hci_uart *) arg; @@ -85,6 +102,8 @@ static int h5_open(struct hci_uart *hu) skb_queue_head_init(&h5->rel); skb_queue_head_init(&h5->unrel); + h5_reset_rx(h5); + init_timer(&h5->timer); h5->timer.function = h5_timed_event; h5->timer.data = (unsigned long) hu; @@ -107,9 +126,204 @@ static int h5_close(struct hci_uart *hu) return 0; } +static void h5_handle_internal_rx(struct hci_uart *hu) +{ + BT_DBG("%s", hu->hdev->name); +} + +static void h5_complete_rx_pkt(struct hci_uart *hu) +{ + struct h5 *h5 = hu->priv; + u8 pkt_type; + + BT_DBG("%s", hu->hdev->name); + + pkt_type = h5->rx_skb->data[1] & 0x0f; + + switch (pkt_type) { + case HCI_EVENT_PKT: + case HCI_ACLDATA_PKT: + case HCI_SCODATA_PKT: + bt_cb(h5->rx_skb)->pkt_type = pkt_type; + + /* Remove Three-wire header */ + skb_pull(h5->rx_skb, 4); + + hci_recv_frame(h5->rx_skb); + h5->rx_skb = NULL; + + break; + + default: + h5_handle_internal_rx(hu); + break; + } + + h5_reset_rx(h5); +} + +static int h5_rx_crc(struct hci_uart *hu, unsigned char c) +{ + struct h5 *h5 = hu->priv; + + BT_DBG("%s 0x%02hhx", hu->hdev->name, c); + + h5_complete_rx_pkt(hu); + h5_reset_rx(h5); + + return 0; +} + +static int h5_rx_payload(struct hci_uart *hu, unsigned char c) +{ + struct h5 *h5 = hu->priv; + const unsigned char *hdr = h5->rx_skb->data; + + BT_DBG("%s 0x%02hhx", hu->hdev->name, c); + + if ((hdr[0] >> 4) & 0x01) { + h5->rx_func = h5_rx_crc; + h5->rx_pending = 2; + } else { + h5_complete_rx_pkt(hu); + h5_reset_rx(h5); + } + + return 0; +} + +static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c) +{ + struct h5 *h5 = hu->priv; + const unsigned char *hdr = h5->rx_skb->data; + + BT_DBG("%s 0x%02hhx", hu->hdev->name, c); + + if (((hdr[0] + hdr[1] + hdr[2] + hdr[3]) & 0xff) != 0xff) { + BT_ERR("Invalid header checksum"); + h5_reset_rx(h5); + return 0; + } + + h5->rx_func = h5_rx_payload; + h5->rx_pending = ((hdr[1] >> 4) & 0xff) + (hdr[2] << 4); + + return 0; +} + +static int h5_rx_pkt_start(struct hci_uart *hu, unsigned char c) +{ + struct h5 *h5 = hu->priv; + + BT_DBG("%s 0x%02hhx", hu->hdev->name, c); + + if (c == SLIP_DELIMITER) + return 1; + + h5->rx_func = h5_rx_3wire_hdr; + h5->rx_pending = 4; + + h5->rx_skb = bt_skb_alloc(H5_MAX_LEN, GFP_ATOMIC); + if (!h5->rx_skb) { + BT_ERR("Can't allocate mem for new packet"); + h5_reset_rx(h5); + return -ENOMEM; + } + + h5->rx_skb->dev = (void *) hu->hdev; + + return 0; +} + +static int h5_rx_delimiter(struct hci_uart *hu, unsigned char c) +{ + struct h5 *h5 = hu->priv; + + BT_DBG("%s 0x%02hhx", hu->hdev->name, c); + + if (c == SLIP_DELIMITER) + h5->rx_func = h5_rx_pkt_start; + + return 1; +} + +static void h5_unslip_one_byte(struct h5 *h5, unsigned char c) +{ + const u8 delim = SLIP_DELIMITER, esc = SLIP_ESC; + const u8 *byte = &c; + + if (!h5->rx_esc && c == SLIP_ESC) { + h5->rx_esc = true; + return; + } + + if (h5->rx_esc) { + switch (c) { + case SLIP_ESC_DELIM: + byte = &delim; + break; + case SLIP_ESC_ESC: + byte = &esc; + break; + default: + BT_ERR("Invalid esc byte 0x%02hhx", c); + h5_reset_rx(h5); + return; + } + + h5->rx_esc = false; + } + + memcpy(skb_put(h5->rx_skb, 1), byte, 1); + h5->rx_pending--; + + BT_DBG("unsliped 0x%02hhx", *byte); +} + +static void h5_reset_rx(struct h5 *h5) +{ + if (h5->rx_skb) { + kfree_skb(h5->rx_skb); + h5->rx_skb = NULL; + } + + h5->rx_func = h5_rx_delimiter; + h5->rx_pending = 0; + h5->rx_esc = false; +} + static int h5_recv(struct hci_uart *hu, void *data, int count) { - return -ENOSYS; + struct h5 *h5 = hu->priv; + unsigned char *ptr = data; + + BT_DBG("%s count %d", hu->hdev->name, count); + + while (count > 0) { + int processed; + + if (h5->rx_pending > 0) { + if (*ptr == SLIP_DELIMITER) { + BT_ERR("Too short H5 packet"); + h5_reset_rx(h5); + continue; + } + + h5_unslip_one_byte(h5, *ptr); + + ptr++; count--; + continue; + } + + processed = h5->rx_func(hu, *ptr); + if (processed < 0) + return processed; + + ptr += processed; + count -= processed; + } + + return 0; } static int h5_enqueue(struct hci_uart *hu, struct sk_buff *skb) |