diff options
| -rw-r--r-- | drivers/bluetooth/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/bluetooth/hci_h5.c | 42 |
2 files changed, 39 insertions, 4 deletions
diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig index 7df69ccb6600..c5d45cf91f88 100644 --- a/drivers/bluetooth/Kconfig +++ b/drivers/bluetooth/Kconfig @@ -188,6 +188,7 @@ config BT_HCIUART_3WIRE bool "Three-wire UART (H5) protocol support" depends on BT_HCIUART depends on BT_HCIUART_SERDEV + select CRC_CCITT help The HCI Three-wire UART Transport Layer makes it possible to user the Bluetooth HCI over a serial port interface. The HCI diff --git a/drivers/bluetooth/hci_h5.c b/drivers/bluetooth/hci_h5.c index 863ee93dd8a8..43371f389fd2 100644 --- a/drivers/bluetooth/hci_h5.c +++ b/drivers/bluetooth/hci_h5.c @@ -7,6 +7,8 @@ */ #include <linux/acpi.h> +#include <linux/bitrev.h> +#include <linux/crc-ccitt.h> #include <linux/errno.h> #include <linux/gpio/consumer.h> #include <linux/kernel.h> @@ -58,6 +60,7 @@ enum { H5_TX_ACK_REQ, /* Pending ack to send */ H5_WAKEUP_DISABLE, /* Device cannot wake host */ H5_HW_FLOW_CONTROL, /* Use HW flow control */ + H5_CRC, /* Use CRC */ }; struct h5 { @@ -141,8 +144,8 @@ static void h5_link_control(struct hci_uart *hu, const void *data, size_t len) static u8 h5_cfg_field(struct h5 *h5) { - /* Sliding window size (first 3 bits) */ - return h5->tx_win & 0x07; + /* Sliding window size (first 3 bits) and CRC request (fifth bit). */ + return (h5->tx_win & 0x07) | 0x10; } static void h5_timed_event(struct timer_list *t) @@ -361,8 +364,10 @@ static void h5_handle_internal_rx(struct hci_uart *hu) h5_link_control(hu, conf_rsp, 2); h5_link_control(hu, conf_req, 3); } else if (memcmp(data, conf_rsp, 2) == 0) { - if (H5_HDR_LEN(hdr) > 2) + if (H5_HDR_LEN(hdr) > 2) { h5->tx_win = (data[2] & 0x07); + assign_bit(H5_CRC, &h5->flags, data[2] & 0x10); + } BT_DBG("Three-wire init complete. tx_win %u", h5->tx_win); h5->state = H5_ACTIVE; hci_uart_init_ready(hu); @@ -426,7 +431,24 @@ static void h5_complete_rx_pkt(struct hci_uart *hu) static int h5_rx_crc(struct hci_uart *hu, unsigned char c) { - h5_complete_rx_pkt(hu); + struct h5 *h5 = hu->priv; + const unsigned char *hdr = h5->rx_skb->data; + u16 crc; + __be16 crc_be; + + crc = crc_ccitt(0xffff, hdr, 4 + H5_HDR_LEN(hdr)); + crc = bitrev16(crc); + + crc_be = cpu_to_be16(crc); + + if (memcmp(&crc_be, hdr + 4 + H5_HDR_LEN(hdr), 2) != 0) { + bt_dev_err(hu->hdev, "Received packet with invalid CRC"); + h5_reset_rx(h5); + } else { + /* Remove CRC bytes */ + skb_trim(h5->rx_skb, 4 + H5_HDR_LEN(hdr)); + h5_complete_rx_pkt(hu); + } return 0; } @@ -557,6 +579,7 @@ static void h5_reset_rx(struct h5 *h5) h5->rx_func = h5_rx_delimiter; h5->rx_pending = 0; clear_bit(H5_RX_ESC, &h5->flags); + clear_bit(H5_CRC, &h5->flags); } static int h5_recv(struct hci_uart *hu, const void *data, int count) @@ -687,6 +710,7 @@ static struct sk_buff *h5_prepare_pkt(struct hci_uart *hu, u8 pkt_type, struct h5 *h5 = hu->priv; struct sk_buff *nskb; u8 hdr[4]; + u16 crc; int i; if (!valid_packet_type(pkt_type)) { @@ -714,6 +738,7 @@ static struct sk_buff *h5_prepare_pkt(struct hci_uart *hu, u8 pkt_type, /* Reliable packet? */ if (pkt_type == HCI_ACLDATA_PKT || pkt_type == HCI_COMMAND_PKT) { hdr[0] |= 1 << 7; + hdr[0] |= (test_bit(H5_CRC, &h5->flags) && 1) << 6; hdr[0] |= h5->tx_seq; h5->tx_seq = (h5->tx_seq + 1) % 8; } @@ -733,6 +758,15 @@ static struct sk_buff *h5_prepare_pkt(struct hci_uart *hu, u8 pkt_type, for (i = 0; i < len; i++) h5_slip_one_byte(nskb, data[i]); + if (H5_HDR_CRC(hdr)) { + crc = crc_ccitt(0xffff, hdr, 4); + crc = crc_ccitt(crc, data, len); + crc = bitrev16(crc); + + h5_slip_one_byte(nskb, (crc >> 8) & 0xff); + h5_slip_one_byte(nskb, crc & 0xff); + } + h5_slip_delim(nskb); return nskb; |