mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 19:00:25 +00:00
![Ohad Ben-Cohen](/assets/img/avatar_default.png)
In the (rare) event of simultaneous mutual wake up requests, do send the chip an explicit wake-up ack. This is required for Texas Instruments's BRF6350 chip. Signed-off-by: Ohad Ben-Cohen <ohad@bencohen.org> Signed-off-by: David S. Miller <davem@davemloft.net>
536 lines
12 KiB
C
536 lines
12 KiB
C
/*
|
|
* Texas Instruments' Bluetooth HCILL UART protocol
|
|
*
|
|
* HCILL (HCI Low Level) is a Texas Instruments' power management
|
|
* protocol extension to H4.
|
|
*
|
|
* Copyright (C) 2007 Texas Instruments, Inc.
|
|
*
|
|
* Written by Ohad Ben-Cohen <ohad@bencohen.org>
|
|
*
|
|
* Acknowledgements:
|
|
* This file is based on hci_h4.c, which was written
|
|
* by Maxim Krasnyansky and Marcel Holtmann.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2
|
|
* as published by the Free Software Foundation
|
|
*
|
|
* 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/module.h>
|
|
#include <linux/kernel.h>
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/types.h>
|
|
#include <linux/fcntl.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/poll.h>
|
|
|
|
#include <linux/slab.h>
|
|
#include <linux/tty.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/string.h>
|
|
#include <linux/signal.h>
|
|
#include <linux/ioctl.h>
|
|
#include <linux/skbuff.h>
|
|
|
|
#include <net/bluetooth/bluetooth.h>
|
|
#include <net/bluetooth/hci_core.h>
|
|
|
|
#include "hci_uart.h"
|
|
|
|
/* HCILL commands */
|
|
#define HCILL_GO_TO_SLEEP_IND 0x30
|
|
#define HCILL_GO_TO_SLEEP_ACK 0x31
|
|
#define HCILL_WAKE_UP_IND 0x32
|
|
#define HCILL_WAKE_UP_ACK 0x33
|
|
|
|
/* HCILL receiver States */
|
|
#define HCILL_W4_PACKET_TYPE 0
|
|
#define HCILL_W4_EVENT_HDR 1
|
|
#define HCILL_W4_ACL_HDR 2
|
|
#define HCILL_W4_SCO_HDR 3
|
|
#define HCILL_W4_DATA 4
|
|
|
|
/* HCILL states */
|
|
enum hcill_states_e {
|
|
HCILL_ASLEEP,
|
|
HCILL_ASLEEP_TO_AWAKE,
|
|
HCILL_AWAKE,
|
|
HCILL_AWAKE_TO_ASLEEP
|
|
};
|
|
|
|
struct hcill_cmd {
|
|
u8 cmd;
|
|
} __attribute__((packed));
|
|
|
|
struct ll_struct {
|
|
unsigned long rx_state;
|
|
unsigned long rx_count;
|
|
struct sk_buff *rx_skb;
|
|
struct sk_buff_head txq;
|
|
spinlock_t hcill_lock; /* HCILL state lock */
|
|
unsigned long hcill_state; /* HCILL power state */
|
|
struct sk_buff_head tx_wait_q; /* HCILL wait queue */
|
|
};
|
|
|
|
/*
|
|
* Builds and sends an HCILL command packet.
|
|
* These are very simple packets with only 1 cmd byte
|
|
*/
|
|
static int send_hcill_cmd(u8 cmd, struct hci_uart *hu)
|
|
{
|
|
int err = 0;
|
|
struct sk_buff *skb = NULL;
|
|
struct ll_struct *ll = hu->priv;
|
|
struct hcill_cmd *hcill_packet;
|
|
|
|
BT_DBG("hu %p cmd 0x%x", hu, cmd);
|
|
|
|
/* allocate packet */
|
|
skb = bt_skb_alloc(1, GFP_ATOMIC);
|
|
if (!skb) {
|
|
BT_ERR("cannot allocate memory for HCILL packet");
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
/* prepare packet */
|
|
hcill_packet = (struct hcill_cmd *) skb_put(skb, 1);
|
|
hcill_packet->cmd = cmd;
|
|
skb->dev = (void *) hu->hdev;
|
|
|
|
/* send packet */
|
|
skb_queue_tail(&ll->txq, skb);
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
/* Initialize protocol */
|
|
static int ll_open(struct hci_uart *hu)
|
|
{
|
|
struct ll_struct *ll;
|
|
|
|
BT_DBG("hu %p", hu);
|
|
|
|
ll = kzalloc(sizeof(*ll), GFP_ATOMIC);
|
|
if (!ll)
|
|
return -ENOMEM;
|
|
|
|
skb_queue_head_init(&ll->txq);
|
|
skb_queue_head_init(&ll->tx_wait_q);
|
|
spin_lock_init(&ll->hcill_lock);
|
|
|
|
ll->hcill_state = HCILL_AWAKE;
|
|
|
|
hu->priv = ll;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Flush protocol data */
|
|
static int ll_flush(struct hci_uart *hu)
|
|
{
|
|
struct ll_struct *ll = hu->priv;
|
|
|
|
BT_DBG("hu %p", hu);
|
|
|
|
skb_queue_purge(&ll->tx_wait_q);
|
|
skb_queue_purge(&ll->txq);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Close protocol */
|
|
static int ll_close(struct hci_uart *hu)
|
|
{
|
|
struct ll_struct *ll = hu->priv;
|
|
|
|
BT_DBG("hu %p", hu);
|
|
|
|
skb_queue_purge(&ll->tx_wait_q);
|
|
skb_queue_purge(&ll->txq);
|
|
|
|
if (ll->rx_skb)
|
|
kfree_skb(ll->rx_skb);
|
|
|
|
hu->priv = NULL;
|
|
|
|
kfree(ll);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* internal function, which does common work of the device wake up process:
|
|
* 1. places all pending packets (waiting in tx_wait_q list) in txq list.
|
|
* 2. changes internal state to HCILL_AWAKE.
|
|
* Note: assumes that hcill_lock spinlock is taken,
|
|
* shouldn't be called otherwise!
|
|
*/
|
|
static void __ll_do_awake(struct ll_struct *ll)
|
|
{
|
|
struct sk_buff *skb = NULL;
|
|
|
|
while ((skb = skb_dequeue(&ll->tx_wait_q)))
|
|
skb_queue_tail(&ll->txq, skb);
|
|
|
|
ll->hcill_state = HCILL_AWAKE;
|
|
}
|
|
|
|
/*
|
|
* Called upon a wake-up-indication from the device
|
|
*/
|
|
static void ll_device_want_to_wakeup(struct hci_uart *hu)
|
|
{
|
|
unsigned long flags;
|
|
struct ll_struct *ll = hu->priv;
|
|
|
|
BT_DBG("hu %p", hu);
|
|
|
|
/* lock hcill state */
|
|
spin_lock_irqsave(&ll->hcill_lock, flags);
|
|
|
|
switch (ll->hcill_state) {
|
|
case HCILL_ASLEEP_TO_AWAKE:
|
|
/*
|
|
* This state means that both the host and the BRF chip
|
|
* have simultaneously sent a wake-up-indication packet.
|
|
* Traditionaly, in this case, receiving a wake-up-indication
|
|
* was enough and an additional wake-up-ack wasn't needed.
|
|
* This has changed with the BRF6350, which does require an
|
|
* explicit wake-up-ack. Other BRF versions, which do not
|
|
* require an explicit ack here, do accept it, thus it is
|
|
* perfectly safe to always send one.
|
|
*/
|
|
BT_DBG("dual wake-up-indication");
|
|
/* deliberate fall-through - do not add break */
|
|
case HCILL_ASLEEP:
|
|
/* acknowledge device wake up */
|
|
if (send_hcill_cmd(HCILL_WAKE_UP_ACK, hu) < 0) {
|
|
BT_ERR("cannot acknowledge device wake up");
|
|
goto out;
|
|
}
|
|
break;
|
|
default:
|
|
/* any other state is illegal */
|
|
BT_ERR("received HCILL_WAKE_UP_IND in state %ld", ll->hcill_state);
|
|
break;
|
|
}
|
|
|
|
/* send pending packets and change state to HCILL_AWAKE */
|
|
__ll_do_awake(ll);
|
|
|
|
out:
|
|
spin_unlock_irqrestore(&ll->hcill_lock, flags);
|
|
|
|
/* actually send the packets */
|
|
hci_uart_tx_wakeup(hu);
|
|
}
|
|
|
|
/*
|
|
* Called upon a sleep-indication from the device
|
|
*/
|
|
static void ll_device_want_to_sleep(struct hci_uart *hu)
|
|
{
|
|
unsigned long flags;
|
|
struct ll_struct *ll = hu->priv;
|
|
|
|
BT_DBG("hu %p", hu);
|
|
|
|
/* lock hcill state */
|
|
spin_lock_irqsave(&ll->hcill_lock, flags);
|
|
|
|
/* sanity check */
|
|
if (ll->hcill_state != HCILL_AWAKE)
|
|
BT_ERR("ERR: HCILL_GO_TO_SLEEP_IND in state %ld", ll->hcill_state);
|
|
|
|
/* acknowledge device sleep */
|
|
if (send_hcill_cmd(HCILL_GO_TO_SLEEP_ACK, hu) < 0) {
|
|
BT_ERR("cannot acknowledge device sleep");
|
|
goto out;
|
|
}
|
|
|
|
/* update state */
|
|
ll->hcill_state = HCILL_ASLEEP;
|
|
|
|
out:
|
|
spin_unlock_irqrestore(&ll->hcill_lock, flags);
|
|
|
|
/* actually send the sleep ack packet */
|
|
hci_uart_tx_wakeup(hu);
|
|
}
|
|
|
|
/*
|
|
* Called upon wake-up-acknowledgement from the device
|
|
*/
|
|
static void ll_device_woke_up(struct hci_uart *hu)
|
|
{
|
|
unsigned long flags;
|
|
struct ll_struct *ll = hu->priv;
|
|
|
|
BT_DBG("hu %p", hu);
|
|
|
|
/* lock hcill state */
|
|
spin_lock_irqsave(&ll->hcill_lock, flags);
|
|
|
|
/* sanity check */
|
|
if (ll->hcill_state != HCILL_ASLEEP_TO_AWAKE)
|
|
BT_ERR("received HCILL_WAKE_UP_ACK in state %ld", ll->hcill_state);
|
|
|
|
/* send pending packets and change state to HCILL_AWAKE */
|
|
__ll_do_awake(ll);
|
|
|
|
spin_unlock_irqrestore(&ll->hcill_lock, flags);
|
|
|
|
/* actually send the packets */
|
|
hci_uart_tx_wakeup(hu);
|
|
}
|
|
|
|
/* Enqueue frame for transmittion (padding, crc, etc) */
|
|
/* may be called from two simultaneous tasklets */
|
|
static int ll_enqueue(struct hci_uart *hu, struct sk_buff *skb)
|
|
{
|
|
unsigned long flags = 0;
|
|
struct ll_struct *ll = hu->priv;
|
|
|
|
BT_DBG("hu %p skb %p", hu, skb);
|
|
|
|
/* Prepend skb with frame type */
|
|
memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
|
|
|
|
/* lock hcill state */
|
|
spin_lock_irqsave(&ll->hcill_lock, flags);
|
|
|
|
/* act according to current state */
|
|
switch (ll->hcill_state) {
|
|
case HCILL_AWAKE:
|
|
BT_DBG("device awake, sending normally");
|
|
skb_queue_tail(&ll->txq, skb);
|
|
break;
|
|
case HCILL_ASLEEP:
|
|
BT_DBG("device asleep, waking up and queueing packet");
|
|
/* save packet for later */
|
|
skb_queue_tail(&ll->tx_wait_q, skb);
|
|
/* awake device */
|
|
if (send_hcill_cmd(HCILL_WAKE_UP_IND, hu) < 0) {
|
|
BT_ERR("cannot wake up device");
|
|
break;
|
|
}
|
|
ll->hcill_state = HCILL_ASLEEP_TO_AWAKE;
|
|
break;
|
|
case HCILL_ASLEEP_TO_AWAKE:
|
|
BT_DBG("device waking up, queueing packet");
|
|
/* transient state; just keep packet for later */
|
|
skb_queue_tail(&ll->tx_wait_q, skb);
|
|
break;
|
|
default:
|
|
BT_ERR("illegal hcill state: %ld (losing packet)", ll->hcill_state);
|
|
kfree_skb(skb);
|
|
break;
|
|
}
|
|
|
|
spin_unlock_irqrestore(&ll->hcill_lock, flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline int ll_check_data_len(struct ll_struct *ll, int len)
|
|
{
|
|
register int room = skb_tailroom(ll->rx_skb);
|
|
|
|
BT_DBG("len %d room %d", len, room);
|
|
|
|
if (!len) {
|
|
hci_recv_frame(ll->rx_skb);
|
|
} else if (len > room) {
|
|
BT_ERR("Data length is too large");
|
|
kfree_skb(ll->rx_skb);
|
|
} else {
|
|
ll->rx_state = HCILL_W4_DATA;
|
|
ll->rx_count = len;
|
|
return len;
|
|
}
|
|
|
|
ll->rx_state = HCILL_W4_PACKET_TYPE;
|
|
ll->rx_skb = NULL;
|
|
ll->rx_count = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Recv data */
|
|
static int ll_recv(struct hci_uart *hu, void *data, int count)
|
|
{
|
|
struct ll_struct *ll = hu->priv;
|
|
register char *ptr;
|
|
struct hci_event_hdr *eh;
|
|
struct hci_acl_hdr *ah;
|
|
struct hci_sco_hdr *sh;
|
|
register int len, type, dlen;
|
|
|
|
BT_DBG("hu %p count %d rx_state %ld rx_count %ld", hu, count, ll->rx_state, ll->rx_count);
|
|
|
|
ptr = data;
|
|
while (count) {
|
|
if (ll->rx_count) {
|
|
len = min_t(unsigned int, ll->rx_count, count);
|
|
memcpy(skb_put(ll->rx_skb, len), ptr, len);
|
|
ll->rx_count -= len; count -= len; ptr += len;
|
|
|
|
if (ll->rx_count)
|
|
continue;
|
|
|
|
switch (ll->rx_state) {
|
|
case HCILL_W4_DATA:
|
|
BT_DBG("Complete data");
|
|
hci_recv_frame(ll->rx_skb);
|
|
|
|
ll->rx_state = HCILL_W4_PACKET_TYPE;
|
|
ll->rx_skb = NULL;
|
|
continue;
|
|
|
|
case HCILL_W4_EVENT_HDR:
|
|
eh = (struct hci_event_hdr *) ll->rx_skb->data;
|
|
|
|
BT_DBG("Event header: evt 0x%2.2x plen %d", eh->evt, eh->plen);
|
|
|
|
ll_check_data_len(ll, eh->plen);
|
|
continue;
|
|
|
|
case HCILL_W4_ACL_HDR:
|
|
ah = (struct hci_acl_hdr *) ll->rx_skb->data;
|
|
dlen = __le16_to_cpu(ah->dlen);
|
|
|
|
BT_DBG("ACL header: dlen %d", dlen);
|
|
|
|
ll_check_data_len(ll, dlen);
|
|
continue;
|
|
|
|
case HCILL_W4_SCO_HDR:
|
|
sh = (struct hci_sco_hdr *) ll->rx_skb->data;
|
|
|
|
BT_DBG("SCO header: dlen %d", sh->dlen);
|
|
|
|
ll_check_data_len(ll, sh->dlen);
|
|
continue;
|
|
}
|
|
}
|
|
|
|
/* HCILL_W4_PACKET_TYPE */
|
|
switch (*ptr) {
|
|
case HCI_EVENT_PKT:
|
|
BT_DBG("Event packet");
|
|
ll->rx_state = HCILL_W4_EVENT_HDR;
|
|
ll->rx_count = HCI_EVENT_HDR_SIZE;
|
|
type = HCI_EVENT_PKT;
|
|
break;
|
|
|
|
case HCI_ACLDATA_PKT:
|
|
BT_DBG("ACL packet");
|
|
ll->rx_state = HCILL_W4_ACL_HDR;
|
|
ll->rx_count = HCI_ACL_HDR_SIZE;
|
|
type = HCI_ACLDATA_PKT;
|
|
break;
|
|
|
|
case HCI_SCODATA_PKT:
|
|
BT_DBG("SCO packet");
|
|
ll->rx_state = HCILL_W4_SCO_HDR;
|
|
ll->rx_count = HCI_SCO_HDR_SIZE;
|
|
type = HCI_SCODATA_PKT;
|
|
break;
|
|
|
|
/* HCILL signals */
|
|
case HCILL_GO_TO_SLEEP_IND:
|
|
BT_DBG("HCILL_GO_TO_SLEEP_IND packet");
|
|
ll_device_want_to_sleep(hu);
|
|
ptr++; count--;
|
|
continue;
|
|
|
|
case HCILL_GO_TO_SLEEP_ACK:
|
|
/* shouldn't happen */
|
|
BT_ERR("received HCILL_GO_TO_SLEEP_ACK (in state %ld)", ll->hcill_state);
|
|
ptr++; count--;
|
|
continue;
|
|
|
|
case HCILL_WAKE_UP_IND:
|
|
BT_DBG("HCILL_WAKE_UP_IND packet");
|
|
ll_device_want_to_wakeup(hu);
|
|
ptr++; count--;
|
|
continue;
|
|
|
|
case HCILL_WAKE_UP_ACK:
|
|
BT_DBG("HCILL_WAKE_UP_ACK packet");
|
|
ll_device_woke_up(hu);
|
|
ptr++; count--;
|
|
continue;
|
|
|
|
default:
|
|
BT_ERR("Unknown HCI packet type %2.2x", (__u8)*ptr);
|
|
hu->hdev->stat.err_rx++;
|
|
ptr++; count--;
|
|
continue;
|
|
};
|
|
|
|
ptr++; count--;
|
|
|
|
/* Allocate packet */
|
|
ll->rx_skb = bt_skb_alloc(HCI_MAX_FRAME_SIZE, GFP_ATOMIC);
|
|
if (!ll->rx_skb) {
|
|
BT_ERR("Can't allocate mem for new packet");
|
|
ll->rx_state = HCILL_W4_PACKET_TYPE;
|
|
ll->rx_count = 0;
|
|
return 0;
|
|
}
|
|
|
|
ll->rx_skb->dev = (void *) hu->hdev;
|
|
bt_cb(ll->rx_skb)->pkt_type = type;
|
|
}
|
|
|
|
return count;
|
|
}
|
|
|
|
static struct sk_buff *ll_dequeue(struct hci_uart *hu)
|
|
{
|
|
struct ll_struct *ll = hu->priv;
|
|
return skb_dequeue(&ll->txq);
|
|
}
|
|
|
|
static struct hci_uart_proto llp = {
|
|
.id = HCI_UART_LL,
|
|
.open = ll_open,
|
|
.close = ll_close,
|
|
.recv = ll_recv,
|
|
.enqueue = ll_enqueue,
|
|
.dequeue = ll_dequeue,
|
|
.flush = ll_flush,
|
|
};
|
|
|
|
int ll_init(void)
|
|
{
|
|
int err = hci_uart_register_proto(&llp);
|
|
|
|
if (!err)
|
|
BT_INFO("HCILL protocol initialized");
|
|
else
|
|
BT_ERR("HCILL protocol registration failed");
|
|
|
|
return err;
|
|
}
|
|
|
|
int ll_deinit(void)
|
|
{
|
|
return hci_uart_unregister_proto(&llp);
|
|
}
|