/* * 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); 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 = hci_event_hdr(ll->rx_skb); 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 = hci_acl_hdr(ll->rx_skb); 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 = hci_sco_hdr(ll->rx_skb); 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 -ENOMEM; } 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); }