diff options
Diffstat (limited to 'drivers/bluetooth/hci_ll.c')
| -rw-r--r-- | drivers/bluetooth/hci_ll.c | 527 |
1 files changed, 527 insertions, 0 deletions
diff --git a/drivers/bluetooth/hci_ll.c b/drivers/bluetooth/hci_ll.c new file mode 100644 index 000000000..9ee24b075 --- /dev/null +++ b/drivers/bluetooth/hci_ll.c @@ -0,0 +1,527 @@ +/* + * 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; +} __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; + + /* 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_KERNEL); + 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); + + 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. + * Traditionally, 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 hci_dev *hdev, struct ll_struct *ll, int len) +{ + int room = skb_tailroom(ll->rx_skb); + + BT_DBG("len %d room %d", len, room); + + if (!len) { + hci_recv_frame(hdev, 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, const void *data, int count) +{ + struct ll_struct *ll = hu->priv; + const char *ptr; + struct hci_event_hdr *eh; + struct hci_acl_hdr *ah; + struct hci_sco_hdr *sh; + 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(hu->hdev, ll->rx_skb); + + ll->rx_state = HCILL_W4_PACKET_TYPE; + ll->rx_skb = NULL; + continue; + + case HCILL_W4_EVENT_HDR: + eh = hci_event_hdr(ll->rx_skb); + + BT_DBG("Event header: evt 0x%2.2x plen %d", eh->evt, eh->plen); + + ll_check_data_len(hu->hdev, ll, eh->plen); + continue; + + case HCILL_W4_ACL_HDR: + ah = hci_acl_hdr(ll->rx_skb); + dlen = __le16_to_cpu(ah->dlen); + + BT_DBG("ACL header: dlen %d", dlen); + + ll_check_data_len(hu->hdev, ll, dlen); + continue; + + case HCILL_W4_SCO_HDR: + sh = hci_sco_hdr(ll->rx_skb); + + BT_DBG("SCO header: dlen %d", sh->dlen); + + ll_check_data_len(hu->hdev, 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 -ENOMEM; + } + + 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 const struct hci_uart_proto llp = { + .id = HCI_UART_LL, + .name = "LL", + .open = ll_open, + .close = ll_close, + .recv = ll_recv, + .enqueue = ll_enqueue, + .dequeue = ll_dequeue, + .flush = ll_flush, +}; + +int __init ll_init(void) +{ + return hci_uart_register_proto(&llp); +} + +int __exit ll_deinit(void) +{ + return hci_uart_unregister_proto(&llp); +} |