From 40f10224df6f00b59ab342e3d9d9ac8b50c8eada Mon Sep 17 00:00:00 2001 From: Johan Hedberg Date: Mon, 16 Jul 2012 16:12:09 +0300 Subject: [PATCH] Bluetooth: Add support for Three-wire Link Control packets This patch adds basic support for parsing and sending Three-wire UART Link Control packets. Signed-off-by: Johan Hedberg Signed-off-by: Gustavo Padovan --- drivers/bluetooth/hci_h5.c | 96 +++++++++++++++++++++++++++++++------- 1 file changed, 79 insertions(+), 17 deletions(-) diff --git a/drivers/bluetooth/hci_h5.c b/drivers/bluetooth/hci_h5.c index 6c7b27e921a5..022a6bcb4323 100644 --- a/drivers/bluetooth/hci_h5.c +++ b/drivers/bluetooth/hci_h5.c @@ -36,6 +36,7 @@ #define H5_TXWINSIZE 4 #define H5_ACK_TIMEOUT msecs_to_jiffies(250) +#define H5_SYNC_TIMEOUT msecs_to_jiffies(100) /* * Maximum Three-wire packet: @@ -65,7 +66,6 @@ struct h5 { size_t rx_pending; /* Expecting more bytes */ bool rx_esc; /* SLIP escape mode */ u8 rx_ack; /* Last ack number received */ - u8 rx_seq; /* Last seq number received */ int (*rx_func) (struct hci_uart *hu, u8 c); @@ -73,6 +73,7 @@ struct h5 { bool tx_ack_req; /* Pending ack to send */ u8 tx_seq; /* Next seq number to send */ + u8 tx_ack; /* Next ack number to send */ }; static void h5_reset_rx(struct h5 *h5); @@ -98,9 +99,26 @@ static void h5_timed_event(unsigned long arg) hci_uart_tx_wakeup(hu); } +static void h5_link_control(struct hci_uart *hu, const void *data, size_t len) +{ + struct h5 *h5 = hu->priv; + struct sk_buff *nskb; + + nskb = alloc_skb(3, GFP_ATOMIC); + if (!nskb) + return; + + bt_cb(nskb)->pkt_type = HCI_3WIRE_LINK_PKT; + + memcpy(skb_put(nskb, len), data, len); + + skb_queue_tail(&h5->unrel, nskb); +} + static int h5_open(struct hci_uart *hu) { struct h5 *h5; + const unsigned char sync[] = { 0x01, 0x7e }; BT_DBG("hu %p", hu); @@ -120,6 +138,10 @@ static int h5_open(struct hci_uart *hu) h5->timer.function = h5_timed_event; h5->timer.data = (unsigned long) hu; + /* Send initial sync request */ + h5_link_control(hu, sync, sizeof(sync)); + mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT); + return 0; } @@ -148,6 +170,8 @@ static void h5_pkt_cull(struct h5 *h5) spin_lock_irqsave(&h5->unack.lock, flags); to_remove = skb_queue_len(&h5->unack); + if (to_remove == 0) + goto unlock; seq = h5->tx_seq; @@ -174,12 +198,44 @@ static void h5_pkt_cull(struct h5 *h5) if (skb_queue_empty(&h5->unack)) del_timer(&h5->timer); +unlock: spin_unlock_irqrestore(&h5->unack.lock, flags); } static void h5_handle_internal_rx(struct hci_uart *hu) { + struct h5 *h5 = hu->priv; + const unsigned char sync_req[] = { 0x01, 0x7e }; + const unsigned char sync_rsp[] = { 0x02, 0x7d }; + const unsigned char conf_req[] = { 0x03, 0xfc, 0x01 }; + const unsigned char conf_rsp[] = { 0x04, 0x7b, 0x01 }; + const unsigned char *hdr = h5->rx_skb->data; + const unsigned char *data = &h5->rx_skb->data[4]; + BT_DBG("%s", hu->hdev->name); + + if (H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT) + return; + + if (H5_HDR_LEN(hdr) < 2) + return; + + if (memcmp(data, sync_req, 2) == 0) { + h5_link_control(hu, sync_rsp, 2); + } else if (memcmp(data, sync_rsp, 2) == 0) { + h5_link_control(hu, conf_req, 3); + } else if (memcmp(data, conf_req, 2) == 0) { + h5_link_control(hu, conf_rsp, 2); + h5_link_control(hu, conf_req, 3); + } else if (memcmp(data, conf_rsp, 2) == 0) { + BT_DBG("Three-wire init sequence complete"); + return; + } else { + BT_DBG("Link Control: 0x%02hhx 0x%02hhx", data[0], data[1]); + return; + } + + hci_uart_tx_wakeup(hu); } static void h5_complete_rx_pkt(struct hci_uart *hu) @@ -190,8 +246,9 @@ static void h5_complete_rx_pkt(struct hci_uart *hu) BT_DBG("%s", hu->hdev->name); if (H5_HDR_RELIABLE(hdr)) { - h5->tx_seq = (h5->tx_seq + 1) % 8; + h5->tx_ack = (h5->tx_ack + 1) % 8; h5->tx_ack_req = true; + hci_uart_tx_wakeup(hu); } h5->rx_ack = H5_HDR_ACK(hdr); @@ -257,15 +314,20 @@ static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c) BT_DBG("%s 0x%02hhx", hu->hdev->name, c); + BT_DBG("%s rx: seq %u ack %u crc %u rel %u type %u len %u", + hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr), + H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr), + H5_HDR_LEN(hdr)); + if (((hdr[0] + hdr[1] + hdr[2] + hdr[3]) & 0xff) != 0xff) { BT_ERR("Invalid header checksum"); h5_reset_rx(h5); return 0; } - if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != h5->tx_seq) { + if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != h5->tx_ack) { BT_ERR("Out-of-order packet arrived (%u != %u)", - H5_HDR_SEQ(hdr), h5->tx_seq); + H5_HDR_SEQ(hdr), h5->tx_ack); h5_reset_rx(h5); return 0; } @@ -444,9 +506,10 @@ static void h5_slip_one_byte(struct sk_buff *skb, u8 c) } } -static struct sk_buff *h5_build_pkt(struct h5 *h5, bool rel, u8 pkt_type, +static struct sk_buff *h5_build_pkt(struct hci_uart *hu, bool rel, u8 pkt_type, const u8 *data, size_t len) { + struct h5 *h5 = hu->priv; struct sk_buff *nskb; u8 hdr[4]; int i; @@ -465,7 +528,7 @@ static struct sk_buff *h5_build_pkt(struct h5 *h5, bool rel, u8 pkt_type, h5_slip_delim(nskb); - hdr[0] = h5->rx_seq << 3; + hdr[0] = h5->tx_ack << 3; h5->tx_ack_req = false; if (rel) { @@ -478,6 +541,11 @@ static struct sk_buff *h5_build_pkt(struct h5 *h5, bool rel, u8 pkt_type, hdr[2] = len >> 4; hdr[3] = ~((hdr[0] + hdr[1] + hdr[2]) & 0xff); + BT_DBG("%s tx: seq %u ack %u crc %u rel %u type %u len %u", + hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr), + H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr), + H5_HDR_LEN(hdr)); + for (i = 0; i < 4; i++) h5_slip_one_byte(nskb, hdr[i]); @@ -489,7 +557,7 @@ static struct sk_buff *h5_build_pkt(struct h5 *h5, bool rel, u8 pkt_type, return nskb; } -static struct sk_buff *h5_prepare_pkt(struct h5 *h5, u8 pkt_type, +static struct sk_buff *h5_prepare_pkt(struct hci_uart *hu, u8 pkt_type, const u8 *data, size_t len) { bool rel; @@ -509,13 +577,7 @@ static struct sk_buff *h5_prepare_pkt(struct h5 *h5, u8 pkt_type, return NULL; } - return h5_build_pkt(h5, rel, pkt_type, data, len); -} - -static struct sk_buff *h5_prepare_ack(struct h5 *h5) -{ - h5->tx_ack_req = false; - return NULL; + return h5_build_pkt(hu, rel, pkt_type, data, len); } static struct sk_buff *h5_dequeue(struct hci_uart *hu) @@ -525,7 +587,7 @@ static struct sk_buff *h5_dequeue(struct hci_uart *hu) struct sk_buff *skb, *nskb; if ((skb = skb_dequeue(&h5->unrel)) != NULL) { - nskb = h5_prepare_pkt(h5, bt_cb(skb)->pkt_type, + nskb = h5_prepare_pkt(hu, bt_cb(skb)->pkt_type, skb->data, skb->len); if (nskb) { kfree_skb(skb); @@ -542,7 +604,7 @@ static struct sk_buff *h5_dequeue(struct hci_uart *hu) goto unlock; if ((skb = skb_dequeue(&h5->rel)) != NULL) { - nskb = h5_prepare_pkt(h5, bt_cb(skb)->pkt_type, + nskb = h5_prepare_pkt(hu, bt_cb(skb)->pkt_type, skb->data, skb->len); if (nskb) { __skb_queue_tail(&h5->unack, skb); @@ -559,7 +621,7 @@ unlock: spin_unlock_irqrestore(&h5->unack.lock, flags); if (h5->tx_ack_req) - return h5_prepare_ack(h5); + return h5_prepare_pkt(hu, HCI_3WIRE_ACK_PKT, NULL, 0); return NULL; } -- 2.30.2