#include "hci_uart.h"
-#define H5_TXWINSIZE 4
+#define HCI_3WIRE_ACK_PKT 0
+#define HCI_3WIRE_LINK_PKT 15
+
+/* Sliding window size */
+#define H5_TX_WIN_MAX 4
#define H5_ACK_TIMEOUT msecs_to_jiffies(250)
+#define H5_SYNC_TIMEOUT msecs_to_jiffies(100)
+
+/*
+ * Maximum Three-wire packet:
+ * 4 byte header + max value for 12-bit length + 2 bytes for CRC
+ */
+#define H5_MAX_LEN (4 + 0xfff + 2)
+
+/* Convenience macros for reading Three-wire header values */
+#define H5_HDR_SEQ(hdr) ((hdr)[0] & 0x07)
+#define H5_HDR_ACK(hdr) (((hdr)[0] >> 3) & 0x07)
+#define H5_HDR_CRC(hdr) (((hdr)[0] >> 6) & 0x01)
+#define H5_HDR_RELIABLE(hdr) (((hdr)[0] >> 7) & 0x01)
+#define H5_HDR_PKT_TYPE(hdr) ((hdr)[1] & 0x0f)
+#define H5_HDR_LEN(hdr) ((((hdr)[1] >> 4) & 0xff) + ((hdr)[2] << 4))
+
+#define SLIP_DELIMITER 0xc0
+#define SLIP_ESC 0xdb
+#define SLIP_ESC_DELIM 0xdc
+#define SLIP_ESC_ESC 0xdd
+
+/* H5 state flags */
+enum {
+ H5_RX_ESC, /* SLIP escape mode */
+ H5_TX_ACK_REQ, /* Pending ack to send */
+};
struct h5 {
- struct sk_buff_head unack; /* Unack'ed packets queue */
- struct sk_buff_head rel; /* Reliable packets queue */
- struct sk_buff_head unrel; /* Unreliable packets queue */
+ struct sk_buff_head unack; /* Unack'ed packets queue */
+ struct sk_buff_head rel; /* Reliable packets queue */
+ struct sk_buff_head unrel; /* Unreliable packets queue */
+
+ unsigned long flags;
+
+ struct sk_buff *rx_skb; /* Receive buffer */
+ size_t rx_pending; /* Expecting more bytes */
+ u8 rx_ack; /* Last ack number received */
- struct sk_buff *rx_skb;
+ int (*rx_func) (struct hci_uart *hu, u8 c);
- struct timer_list timer; /* Retransmission timer */
+ struct timer_list timer; /* Retransmission timer */
- bool txack_req;
+ u8 tx_seq; /* Next seq number to send */
+ u8 tx_ack; /* Next ack number to send */
+ u8 tx_win; /* Sliding window size */
- u8 msgq_txseq;
+ enum {
+ H5_UNINITIALIZED,
+ H5_INITIALIZED,
+ H5_ACTIVE,
+ } state;
+
+ enum {
+ H5_AWAKE,
+ H5_SLEEPING,
+ H5_WAKING_UP,
+ } sleep;
};
+static void h5_reset_rx(struct h5 *h5);
+
+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 u8 h5_cfg_field(struct h5 *h5)
+{
+ u8 field = 0;
+
+ /* Sliding window size (first 3 bits) */
+ field |= (h5->tx_win & 7);
+
+ return field;
+}
+
static void h5_timed_event(unsigned long arg)
{
+ const unsigned char sync_req[] = { 0x01, 0x7e };
+ unsigned char conf_req[] = { 0x03, 0xfc, 0x01 };
struct hci_uart *hu = (struct hci_uart *) arg;
struct h5 *h5 = hu->priv;
struct sk_buff *skb;
unsigned long flags;
+ BT_DBG("%s", hu->hdev->name);
+
+ if (h5->state == H5_UNINITIALIZED)
+ h5_link_control(hu, sync_req, sizeof(sync_req));
+
+ if (h5->state == H5_INITIALIZED) {
+ conf_req[2] = h5_cfg_field(h5);
+ h5_link_control(hu, conf_req, sizeof(conf_req));
+ }
+
+ if (h5->state != H5_ACTIVE) {
+ mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
+ goto wakeup;
+ }
+
+ if (h5->sleep != H5_AWAKE) {
+ h5->sleep = H5_SLEEPING;
+ goto wakeup;
+ }
+
BT_DBG("hu %p retransmitting %u pkts", hu, h5->unack.qlen);
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->tx_seq = (h5->tx_seq - 1) & 0x07;
skb_queue_head(&h5->rel, skb);
}
spin_unlock_irqrestore(&h5->unack.lock, flags);
+wakeup:
hci_uart_tx_wakeup(hu);
}
static int h5_open(struct hci_uart *hu)
{
struct h5 *h5;
+ const unsigned char sync[] = { 0x01, 0x7e };
BT_DBG("hu %p", hu);
skb_queue_head_init(&h5->rel);
skb_queue_head_init(&h5->unrel);
+ h5_reset_rx(h5);
+
init_timer(&h5->timer);
h5->timer.function = h5_timed_event;
h5->timer.data = (unsigned long) hu;
+ h5->tx_win = H5_TX_WIN_MAX;
+
+ set_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags);
+
+ /* Send initial sync request */
+ h5_link_control(hu, sync, sizeof(sync));
+ mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
+
return 0;
}
return 0;
}
+static void h5_pkt_cull(struct h5 *h5)
+{
+ struct sk_buff *skb, *tmp;
+ unsigned long flags;
+ int i, to_remove;
+ u8 seq;
+
+ spin_lock_irqsave(&h5->unack.lock, flags);
+
+ to_remove = skb_queue_len(&h5->unack);
+ if (to_remove == 0)
+ goto unlock;
+
+ seq = h5->tx_seq;
+
+ while (to_remove > 0) {
+ if (h5->rx_ack == seq)
+ break;
+
+ to_remove--;
+ seq = (seq - 1) % 8;
+ }
+
+ if (seq != h5->rx_ack)
+ BT_ERR("Controller acked invalid packet");
+
+ i = 0;
+ skb_queue_walk_safe(&h5->unack, skb, tmp) {
+ if (i++ >= to_remove)
+ break;
+
+ __skb_unlink(skb, &h5->unack);
+ kfree_skb(skb);
+ }
+
+ 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 };
+ unsigned char conf_req[] = { 0x03, 0xfc, 0x01 };
+ const unsigned char conf_rsp[] = { 0x04, 0x7b };
+ const unsigned char wakeup_req[] = { 0x05, 0xfa };
+ const unsigned char woken_req[] = { 0x06, 0xf9 };
+ const unsigned char sleep_req[] = { 0x07, 0x78 };
+ 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;
+
+ conf_req[2] = h5_cfg_field(h5);
+
+ if (memcmp(data, sync_req, 2) == 0) {
+ h5_link_control(hu, sync_rsp, 2);
+ } else if (memcmp(data, sync_rsp, 2) == 0) {
+ h5->state = H5_INITIALIZED;
+ 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) {
+ if (H5_HDR_LEN(hdr) > 2)
+ h5->tx_win = (data[2] & 7);
+ BT_DBG("Three-wire init complete. tx_win %u", h5->tx_win);
+ h5->state = H5_ACTIVE;
+ hci_uart_init_ready(hu);
+ return;
+ } else if (memcmp(data, sleep_req, 2) == 0) {
+ BT_DBG("Peer went to sleep");
+ h5->sleep = H5_SLEEPING;
+ return;
+ } else if (memcmp(data, woken_req, 2) == 0) {
+ BT_DBG("Peer woke up");
+ h5->sleep = H5_AWAKE;
+ } else if (memcmp(data, wakeup_req, 2) == 0) {
+ BT_DBG("Peer requested wakeup");
+ h5_link_control(hu, woken_req, 2);
+ h5->sleep = H5_AWAKE;
+ } 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)
+{
+ struct h5 *h5 = hu->priv;
+ const unsigned char *hdr = h5->rx_skb->data;
+
+ if (H5_HDR_RELIABLE(hdr)) {
+ h5->tx_ack = (h5->tx_ack + 1) % 8;
+ set_bit(H5_TX_ACK_REQ, &h5->flags);
+ hci_uart_tx_wakeup(hu);
+ }
+
+ h5->rx_ack = H5_HDR_ACK(hdr);
+
+ h5_pkt_cull(h5);
+
+ switch (H5_HDR_PKT_TYPE(hdr)) {
+ case HCI_EVENT_PKT:
+ case HCI_ACLDATA_PKT:
+ case HCI_SCODATA_PKT:
+ bt_cb(h5->rx_skb)->pkt_type = H5_HDR_PKT_TYPE(hdr);
+
+ /* Remove Three-wire header */
+ skb_pull(h5->rx_skb, 4);
+
+ hci_recv_frame(h5->rx_skb);
+ h5->rx_skb = NULL;
+
+ break;
+
+ default:
+ h5_handle_internal_rx(hu);
+ break;
+ }
+
+ h5_reset_rx(h5);
+}
+
+static int h5_rx_crc(struct hci_uart *hu, unsigned char c)
+{
+ struct h5 *h5 = hu->priv;
+
+ h5_complete_rx_pkt(hu);
+ h5_reset_rx(h5);
+
+ return 0;
+}
+
+static int h5_rx_payload(struct hci_uart *hu, unsigned char c)
+{
+ struct h5 *h5 = hu->priv;
+ const unsigned char *hdr = h5->rx_skb->data;
+
+ if (H5_HDR_CRC(hdr)) {
+ h5->rx_func = h5_rx_crc;
+ h5->rx_pending = 2;
+ } else {
+ h5_complete_rx_pkt(hu);
+ h5_reset_rx(h5);
+ }
+
+ return 0;
+}
+
+static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c)
+{
+ struct h5 *h5 = hu->priv;
+ const unsigned char *hdr = h5->rx_skb->data;
+
+ 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_ack) {
+ BT_ERR("Out-of-order packet arrived (%u != %u)",
+ H5_HDR_SEQ(hdr), h5->tx_ack);
+ h5_reset_rx(h5);
+ return 0;
+ }
+
+ if (h5->state != H5_ACTIVE &&
+ H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT) {
+ BT_ERR("Non-link packet received in non-active state");
+ h5_reset_rx(h5);
+ }
+
+ h5->rx_func = h5_rx_payload;
+ h5->rx_pending = H5_HDR_LEN(hdr);
+
+ return 0;
+}
+
+static int h5_rx_pkt_start(struct hci_uart *hu, unsigned char c)
+{
+ struct h5 *h5 = hu->priv;
+
+ if (c == SLIP_DELIMITER)
+ return 1;
+
+ h5->rx_func = h5_rx_3wire_hdr;
+ h5->rx_pending = 4;
+
+ h5->rx_skb = bt_skb_alloc(H5_MAX_LEN, GFP_ATOMIC);
+ if (!h5->rx_skb) {
+ BT_ERR("Can't allocate mem for new packet");
+ h5_reset_rx(h5);
+ return -ENOMEM;
+ }
+
+ h5->rx_skb->dev = (void *) hu->hdev;
+
+ return 0;
+}
+
+static int h5_rx_delimiter(struct hci_uart *hu, unsigned char c)
+{
+ struct h5 *h5 = hu->priv;
+
+ if (c == SLIP_DELIMITER)
+ h5->rx_func = h5_rx_pkt_start;
+
+ return 1;
+}
+
+static void h5_unslip_one_byte(struct h5 *h5, unsigned char c)
+{
+ const u8 delim = SLIP_DELIMITER, esc = SLIP_ESC;
+ const u8 *byte = &c;
+
+ if (!test_bit(H5_RX_ESC, &h5->flags) && c == SLIP_ESC) {
+ set_bit(H5_RX_ESC, &h5->flags);
+ return;
+ }
+
+ if (test_and_clear_bit(H5_RX_ESC, &h5->flags)) {
+ switch (c) {
+ case SLIP_ESC_DELIM:
+ byte = &delim;
+ break;
+ case SLIP_ESC_ESC:
+ byte = &esc;
+ break;
+ default:
+ BT_ERR("Invalid esc byte 0x%02hhx", c);
+ h5_reset_rx(h5);
+ return;
+ }
+ }
+
+ memcpy(skb_put(h5->rx_skb, 1), byte, 1);
+ h5->rx_pending--;
+
+ BT_DBG("unsliped 0x%02hhx, rx_pending %zu", *byte, h5->rx_pending);
+}
+
+static void h5_reset_rx(struct h5 *h5)
+{
+ if (h5->rx_skb) {
+ kfree_skb(h5->rx_skb);
+ h5->rx_skb = NULL;
+ }
+
+ h5->rx_func = h5_rx_delimiter;
+ h5->rx_pending = 0;
+ clear_bit(H5_RX_ESC, &h5->flags);
+}
+
static int h5_recv(struct hci_uart *hu, void *data, int count)
{
- return -ENOSYS;
+ struct h5 *h5 = hu->priv;
+ unsigned char *ptr = data;
+
+ BT_DBG("%s pending %zu count %d", hu->hdev->name, h5->rx_pending,
+ count);
+
+ while (count > 0) {
+ int processed;
+
+ if (h5->rx_pending > 0) {
+ if (*ptr == SLIP_DELIMITER) {
+ BT_ERR("Too short H5 packet");
+ h5_reset_rx(h5);
+ continue;
+ }
+
+ h5_unslip_one_byte(h5, *ptr);
+
+ ptr++; count--;
+ continue;
+ }
+
+ processed = h5->rx_func(hu, *ptr);
+ if (processed < 0)
+ return processed;
+
+ ptr += processed;
+ count -= processed;
+ }
+
+ return 0;
}
static int h5_enqueue(struct hci_uart *hu, struct sk_buff *skb)
return 0;
}
+ if (h5->state != H5_ACTIVE) {
+ BT_ERR("Ignoring HCI data in non-active state");
+ kfree_skb(skb);
+ return 0;
+ }
+
switch (bt_cb(skb)->pkt_type) {
case HCI_ACLDATA_PKT:
case HCI_COMMAND_PKT:
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)
{
- h5->txack_req = false;
- return NULL;
+ const char delim = SLIP_DELIMITER;
+
+ memcpy(skb_put(skb, 1), &delim, 1);
}
-static struct sk_buff *h5_prepare_ack(struct h5 *h5)
+static void h5_slip_one_byte(struct sk_buff *skb, u8 c)
{
- h5->txack_req = false;
- return NULL;
+ 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 bool valid_packet_type(u8 type)
+{
+ switch (type) {
+ case HCI_ACLDATA_PKT:
+ case HCI_COMMAND_PKT:
+ case HCI_SCODATA_PKT:
+ case HCI_3WIRE_LINK_PKT:
+ case HCI_3WIRE_ACK_PKT:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static struct sk_buff *h5_prepare_pkt(struct hci_uart *hu, u8 pkt_type,
+ const u8 *data, size_t len)
+{
+ struct h5 *h5 = hu->priv;
+ struct sk_buff *nskb;
+ u8 hdr[4];
+ int i;
+
+ if (!valid_packet_type(pkt_type)) {
+ BT_ERR("Unknown packet type %u", pkt_type);
+ return NULL;
+ }
+
+ /*
+ * 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->tx_ack << 3;
+ clear_bit(H5_TX_ACK_REQ, &h5->flags);
+
+ /* Reliable packet? */
+ if (pkt_type == HCI_ACLDATA_PKT || pkt_type == HCI_COMMAND_PKT) {
+ hdr[0] |= 1 << 7;
+ hdr[0] |= h5->tx_seq;
+ h5->tx_seq = (h5->tx_seq + 1) % 8;
+ }
+
+ hdr[1] = pkt_type | ((len & 0x0f) << 4);
+ 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]);
+
+ for (i = 0; i < len; i++)
+ h5_slip_one_byte(nskb, data[i]);
+
+ h5_slip_delim(nskb);
+
+ return nskb;
}
static struct sk_buff *h5_dequeue(struct hci_uart *hu)
unsigned long flags;
struct sk_buff *skb, *nskb;
+ if (h5->sleep != H5_AWAKE) {
+ const unsigned char wakeup_req[] = { 0x05, 0xfa };
+
+ if (h5->sleep == H5_WAKING_UP)
+ return NULL;
+
+ h5->sleep = H5_WAKING_UP;
+ BT_DBG("Sending wakeup request");
+
+ mod_timer(&h5->timer, jiffies + HZ / 100);
+ return h5_prepare_pkt(hu, HCI_3WIRE_LINK_PKT, wakeup_req, 2);
+ }
+
if ((skb = skb_dequeue(&h5->unrel)) != NULL) {
- nskb = h5_prepare_pkt(h5, skb);
+ nskb = h5_prepare_pkt(hu, bt_cb(skb)->pkt_type,
+ skb->data, skb->len);
if (nskb) {
kfree_skb(skb);
return nskb;
spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
- if (h5->unack.qlen >= H5_TXWINSIZE)
+ if (h5->unack.qlen >= h5->tx_win)
goto unlock;
if ((skb = skb_dequeue(&h5->rel)) != NULL) {
- nskb = h5_prepare_pkt(h5, skb);
-
+ nskb = h5_prepare_pkt(hu, 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);
unlock:
spin_unlock_irqrestore(&h5->unack.lock, flags);
- if (h5->txack_req)
- return h5_prepare_ack(h5);
+ if (test_bit(H5_TX_ACK_REQ, &h5->flags))
+ return h5_prepare_pkt(hu, HCI_3WIRE_ACK_PKT, NULL, 0);
return NULL;
}
projects / deliverable / linux.git / blobdiff