Commit 40f10224 authored by Johan Hedberg's avatar Johan Hedberg Committed by Gustavo Padovan

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: default avatarJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: default avatarGustavo Padovan <gustavo.padovan@collabora.co.uk>
parent 43eb12d7
......@@ -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;
}
......
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