| /* |
| * |
| * Bluetooth HCI Three-wire UART driver |
| * |
| * Copyright (C) 2012 Intel Corporation |
| * |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| * |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/errno.h> |
| #include <linux/skbuff.h> |
| |
| #include <net/bluetooth/bluetooth.h> |
| #include <net/bluetooth/hci_core.h> |
| |
| #include "hci_uart.h" |
| |
| #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 */ |
| |
| unsigned long flags; |
| |
| struct sk_buff *rx_skb; /* Receive buffer */ |
| size_t rx_pending; /* Expecting more bytes */ |
| u8 rx_ack; /* Last ack number received */ |
| |
| int (*rx_func) (struct hci_uart *hu, u8 c); |
| |
| struct timer_list timer; /* Retransmission timer */ |
| |
| u8 tx_seq; /* Next seq number to send */ |
| u8 tx_ack; /* Next ack number to send */ |
| u8 tx_win; /* Sliding window size */ |
| |
| 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->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); |
| |
| h5 = kzalloc(sizeof(*h5), GFP_KERNEL); |
| if (!h5) |
| return -ENOMEM; |
| |
| hu->priv = h5; |
| |
| skb_queue_head_init(&h5->unack); |
| 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; |
| } |
| |
| static int h5_close(struct hci_uart *hu) |
| { |
| struct h5 *h5 = hu->priv; |
| |
| skb_queue_purge(&h5->unack); |
| skb_queue_purge(&h5->rel); |
| skb_queue_purge(&h5->unrel); |
| |
| del_timer(&h5->timer); |
| |
| kfree(h5); |
| |
| 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) & 0x07; |
| } |
| |
| 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); |
| return 0; |
| } |
| |
| 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) |
| { |
| 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) |
| { |
| struct h5 *h5 = hu->priv; |
| |
| if (skb->len > 0xfff) { |
| BT_ERR("Packet too long (%u bytes)", skb->len); |
| kfree_skb(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: |
| skb_queue_tail(&h5->rel, skb); |
| break; |
| |
| case HCI_SCODATA_PKT: |
| skb_queue_tail(&h5->unrel, skb); |
| break; |
| |
| default: |
| BT_ERR("Unknown packet type %u", bt_cb(skb)->pkt_type); |
| kfree_skb(skb); |
| break; |
| } |
| |
| return 0; |
| } |
| |
| 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 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) |
| { |
| struct h5 *h5 = hu->priv; |
| 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(hu, bt_cb(skb)->pkt_type, |
| skb->data, skb->len); |
| if (nskb) { |
| kfree_skb(skb); |
| return nskb; |
| } |
| |
| skb_queue_head(&h5->unrel, skb); |
| BT_ERR("Could not dequeue pkt because alloc_skb failed"); |
| } |
| |
| spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING); |
| |
| if (h5->unack.qlen >= h5->tx_win) |
| goto unlock; |
| |
| if ((skb = skb_dequeue(&h5->rel)) != NULL) { |
| 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); |
| spin_unlock_irqrestore(&h5->unack.lock, flags); |
| return nskb; |
| } |
| |
| skb_queue_head(&h5->rel, skb); |
| BT_ERR("Could not dequeue pkt because alloc_skb failed"); |
| } |
| |
| unlock: |
| spin_unlock_irqrestore(&h5->unack.lock, flags); |
| |
| if (test_bit(H5_TX_ACK_REQ, &h5->flags)) |
| return h5_prepare_pkt(hu, HCI_3WIRE_ACK_PKT, NULL, 0); |
| |
| return NULL; |
| } |
| |
| static int h5_flush(struct hci_uart *hu) |
| { |
| BT_DBG("hu %p", hu); |
| return 0; |
| } |
| |
| static struct hci_uart_proto h5p = { |
| .id = HCI_UART_3WIRE, |
| .open = h5_open, |
| .close = h5_close, |
| .recv = h5_recv, |
| .enqueue = h5_enqueue, |
| .dequeue = h5_dequeue, |
| .flush = h5_flush, |
| }; |
| |
| int __init h5_init(void) |
| { |
| int err = hci_uart_register_proto(&h5p); |
| |
| if (!err) |
| BT_INFO("HCI Three-wire UART (H5) protocol initialized"); |
| else |
| BT_ERR("HCI Three-wire UART (H5) protocol init failed"); |
| |
| return err; |
| } |
| |
| int __exit h5_deinit(void) |
| { |
| return hci_uart_unregister_proto(&h5p); |
| } |