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 <johan.hedberg@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
This commit is contained in:
Johan Hedberg 2012-07-16 16:12:06 +03:00 committed by Gustavo Padovan
parent bc1f35b911
commit c0a1b73c3f

View File

@ -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);