From c0a1b73c3f7d0cf3a93b58507b411911659d1b6a Mon Sep 17 00:00:00 2001 From: Johan Hedberg Date: Mon, 16 Jul 2012 16:12:06 +0300 Subject: [PATCH] Bluetooth: Add initial packet sending support to Three-wire UART This patch adds initial packed encoding and sending support to the Three-wire UART HCI transport driver. Signed-off-by: Johan Hedberg Signed-off-by: Gustavo Padovan --- drivers/bluetooth/hci_h5.c | 105 ++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 98 insertions(+), 7 deletions(-) diff --git a/drivers/bluetooth/hci_h5.c b/drivers/bluetooth/hci_h5.c index ddf7ebb..6df4c07 100644 --- a/drivers/bluetooth/hci_h5.c +++ b/drivers/bluetooth/hci_h5.c @@ -30,6 +30,9 @@ #include "hci_uart.h" +#define HCI_3WIRE_ACK_PKT 0 +#define HCI_3WIRE_LINK_PKT 15 + #define H5_TXWINSIZE 4 #define H5_ACK_TIMEOUT msecs_to_jiffies(250) @@ -60,7 +63,8 @@ struct h5 { bool txack_req; - u8 msgq_txseq; + u8 next_ack; + u8 next_seq; }; static void h5_reset_rx(struct h5 *h5); @@ -77,7 +81,7 @@ static void h5_timed_event(unsigned long arg) spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING); while ((skb = __skb_dequeue_tail(&h5->unack)) != NULL) { - h5->msgq_txseq = (h5->msgq_txseq - 1) & 0x07; + h5->next_seq = (h5->next_seq - 1) & 0x07; skb_queue_head(&h5->rel, skb); } @@ -355,10 +359,96 @@ static int h5_enqueue(struct hci_uart *hu, struct sk_buff *skb) return 0; } -static struct sk_buff *h5_prepare_pkt(struct h5 *h5, struct sk_buff *skb) +static void h5_slip_delim(struct sk_buff *skb) +{ + const char delim = SLIP_DELIMITER; + + memcpy(skb_put(skb, 1), &delim, 1); +} + +static void h5_slip_one_byte(struct sk_buff *skb, u8 c) +{ + const char esc_delim[2] = { SLIP_ESC, SLIP_ESC_DELIM }; + const char esc_esc[2] = { SLIP_ESC, SLIP_ESC_ESC }; + + switch (c) { + case SLIP_DELIMITER: + memcpy(skb_put(skb, 2), &esc_delim, 2); + break; + case SLIP_ESC: + memcpy(skb_put(skb, 2), &esc_esc, 2); + break; + default: + memcpy(skb_put(skb, 1), &c, 1); + } +} + +static struct sk_buff *h5_build_pkt(struct h5 *h5, bool rel, u8 pkt_type, + const u8 *data, size_t len) { + struct sk_buff *nskb; + u8 hdr[4]; + int i; + + /* + * Max len of packet: (original len + 4 (H5 hdr) + 2 (crc)) * 2 + * (because bytes 0xc0 and 0xdb are escaped, worst case is when + * the packet is all made of 0xc0 and 0xdb) + 2 (0xc0 + * delimiters at start and end). + */ + nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC); + if (!nskb) + return NULL; + + bt_cb(nskb)->pkt_type = pkt_type; + + h5_slip_delim(nskb); + + hdr[0] = h5->next_ack << 3; h5->txack_req = false; - return NULL; + + if (rel) { + hdr[0] |= 1 << 7; + hdr[0] |= h5->next_seq; + h5->next_seq = (h5->next_seq + 1) % 8; + } + + hdr[1] = pkt_type | ((len & 0x0f) << 4); + hdr[2] = len >> 4; + hdr[3] = ~((hdr[0] + hdr[1] + hdr[2]) & 0xff); + + for (i = 0; i < 4; i++) + h5_slip_one_byte(nskb, hdr[i]); + + for (i = 0; i < len; i++) + h5_slip_one_byte(nskb, data[i]); + + h5_slip_delim(nskb); + + return nskb; +} + +static struct sk_buff *h5_prepare_pkt(struct h5 *h5, u8 pkt_type, + const u8 *data, size_t len) +{ + bool rel; + + switch (pkt_type) { + case HCI_ACLDATA_PKT: + case HCI_COMMAND_PKT: + rel = true; + break; + case HCI_SCODATA_PKT: + case HCI_3WIRE_LINK_PKT: + case HCI_3WIRE_ACK_PKT: + rel = false; + break; + default: + BT_ERR("Unknown packet type %u", pkt_type); + return NULL; + } + + return h5_build_pkt(h5, rel, pkt_type, data, len); } static struct sk_buff *h5_prepare_ack(struct h5 *h5) @@ -374,7 +464,8 @@ 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, skb); + nskb = h5_prepare_pkt(h5, bt_cb(skb)->pkt_type, + skb->data, skb->len); if (nskb) { kfree_skb(skb); return nskb; @@ -390,8 +481,8 @@ static struct sk_buff *h5_dequeue(struct hci_uart *hu) goto unlock; if ((skb = skb_dequeue(&h5->rel)) != NULL) { - nskb = h5_prepare_pkt(h5, skb); - + nskb = h5_prepare_pkt(h5, bt_cb(skb)->pkt_type, + skb->data, skb->len); if (nskb) { __skb_queue_tail(&h5->unack, skb); mod_timer(&h5->timer, jiffies + H5_ACK_TIMEOUT); -- 2.7.4