[Bluetooth] Add UART driver for Texas Instruments' BRF63xx chips
Add support for Texas Instruments' HCI Low Level (HCILL) Bluetooth
protocol, which is a power management extension to H4. The HCILL is
widely used by TI's BRF63xx Bluetooth chips.
Signed-off-by: Ohad Ben-Cohen <ohad@bencohen.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/drivers/bluetooth/hci_ll.c b/drivers/bluetooth/hci_ll.c
new file mode 100644
index 0000000..8c3e62a
--- /dev/null
+++ b/drivers/bluetooth/hci_ll.c
@@ -0,0 +1,531 @@
+/*
+ * 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:
+ /* acknowledge device wake up */
+ if (send_hcill_cmd(HCILL_WAKE_UP_ACK, hu) < 0) {
+ BT_ERR("cannot acknowledge device wake up");
+ goto out;
+ }
+ break;
+ case HCILL_ASLEEP_TO_AWAKE:
+ /*
+ * this state means that a wake-up-indication
+ * is already on its way to the device,
+ * and will serve as the required wake-up-ack
+ */
+ BT_DBG("dual wake-up-indication");
+ break;
+ default:
+ /* any other state are 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);
+}