linux/drivers/bluetooth/hci_h5.c
Marcel Holtmann 01009eec70 Bluetooth: hci_uart: Remove the manual protocol init message
The init function for each HCI UART protocol prints the same on success
and failure. This information is so generic, remove it and let the main
HCI UART handling print it instead.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
2015-04-07 18:47:10 +02:00

766 lines
16 KiB
C

/*
*
* 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 void h5_peer_reset(struct hci_uart *hu)
{
struct h5 *h5 = hu->priv;
BT_ERR("Peer device has reset");
h5->state = H5_UNINITIALIZED;
del_timer(&h5->timer);
skb_queue_purge(&h5->rel);
skb_queue_purge(&h5->unrel);
skb_queue_purge(&h5->unack);
h5->tx_seq = 0;
h5->tx_ack = 0;
/* Send reset request to upper stack */
hci_reset_dev(hu->hdev);
}
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;
del_timer_sync(&h5->timer);
skb_queue_purge(&h5->unack);
skb_queue_purge(&h5->rel);
skb_queue_purge(&h5->unrel);
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) {
if (h5->state == H5_ACTIVE)
h5_peer_reset(hu);
h5_link_control(hu, sync_rsp, 2);
} else if (memcmp(data, sync_rsp, 2) == 0) {
if (h5->state == H5_ACTIVE)
h5_peer_reset(hu);
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(hu->hdev, 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)
{
h5_complete_rx_pkt(hu);
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);
}
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, const void *data, int count)
{
struct h5 *h5 = hu->priv;
const 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);
}
skb = skb_dequeue(&h5->unrel);
if (skb != 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;
skb = skb_dequeue(&h5->rel);
if (skb != 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 const struct hci_uart_proto h5p = {
.id = HCI_UART_3WIRE,
.name = "Three-wire (H5)",
.open = h5_open,
.close = h5_close,
.recv = h5_recv,
.enqueue = h5_enqueue,
.dequeue = h5_dequeue,
.flush = h5_flush,
};
int __init h5_init(void)
{
return hci_uart_register_proto(&h5p);
}
int __exit h5_deinit(void)
{
return hci_uart_unregister_proto(&h5p);
}