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Release 4.11 drivers/bluetooth/hci_ll.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;
} 
__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; }

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Ohad Ben-Cohen116100.00%1100.00%
Total116100.00%1100.00%

/* 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; }

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Ohad Ben-Cohen8398.81%150.00%
David Herrmann11.19%150.00%
Total84100.00%2100.00%

/* 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; }

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Ohad Ben-Cohen46100.00%1100.00%
Total46100.00%1100.00%

/* 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; }

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Ohad Ben-Cohen64100.00%1100.00%
Total64100.00%1100.00%

/* * 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; }

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Ohad Ben-Cohen48100.00%1100.00%
Total48100.00%1100.00%

/* * 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); }

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Ohad Ben-Cohen12199.18%266.67%
Lucas De Marchi10.82%133.33%
Total122100.00%3100.00%

/* * 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); }

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Ohad Ben-Cohen107100.00%1100.00%
Total107100.00%1100.00%

/* * 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); }

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Ohad Ben-Cohen82100.00%1100.00%
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/* 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), &hci_skb_pkt_type(skb), 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; }

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Ohad Ben-Cohen19299.48%150.00%
Marcel Holtmann10.52%150.00%
Total193100.00%2100.00%


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; }

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Ohad Ben-Cohen10893.91%150.00%
Marcel Holtmann76.09%150.00%
Total115100.00%2100.00%

/* 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; } hci_skb_pkt_type(ll->rx_skb) = type; } return count; }

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Ohad Ben-Cohen51795.04%116.67%
Marcel Holtmann193.49%350.00%
Gustavo Fernando Padovan81.47%233.33%
Total544100.00%6100.00%


static struct sk_buff *ll_dequeue(struct hci_uart *hu) { struct ll_struct *ll = hu->priv; return skb_dequeue(&ll->txq); }

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Ohad Ben-Cohen31100.00%1100.00%
Total31100.00%1100.00%

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); }

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Ohad Ben-Cohen1386.67%133.33%
Marcel Holtmann16.67%133.33%
Gustavo Fernando Padovan16.67%133.33%
Total15100.00%3100.00%


int __exit ll_deinit(void) { return hci_uart_unregister_proto(&llp); }

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Ohad Ben-Cohen1493.33%150.00%
Gustavo Fernando Padovan16.67%150.00%
Total15100.00%2100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Ohad Ben-Cohen174897.38%214.29%
Marcel Holtmann341.89%642.86%
Gustavo Fernando Padovan110.61%428.57%
Lucas De Marchi10.06%17.14%
David Herrmann10.06%17.14%
Total1795100.00%14100.00%
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