/* * * Bluetooth HCI UART driver * * Copyright (C) 2000-2001 Qualcomm Incorporated * Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com> * Copyright (C) 2004-2005 Marcel Holtmann <marcel@holtmann.org> * * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * 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/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" #ifndef CONFIG_BT_HCIUART_DEBUG #undef BT_DBG #define BT_DBG( A... ) #endif #define VERSION "2.2" static int reset = 0; static struct hci_uart_proto *hup[HCI_UART_MAX_PROTO]; int hci_uart_register_proto(struct hci_uart_proto *p) { if (p->id >= HCI_UART_MAX_PROTO) return -EINVAL; if (hup[p->id]) return -EEXIST; hup[p->id] = p; return 0; } int hci_uart_unregister_proto(struct hci_uart_proto *p) { if (p->id >= HCI_UART_MAX_PROTO) return -EINVAL; if (!hup[p->id]) return -EINVAL; hup[p->id] = NULL; return 0; } static struct hci_uart_proto *hci_uart_get_proto(unsigned int id) { if (id >= HCI_UART_MAX_PROTO) return NULL; return hup[id]; } static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type) { struct hci_dev *hdev = hu->hdev; /* Update HCI stat counters */ switch (pkt_type) { case HCI_COMMAND_PKT: hdev->stat.cmd_tx++; break; case HCI_ACLDATA_PKT: hdev->stat.acl_tx++; break; case HCI_SCODATA_PKT: hdev->stat.cmd_tx++; break; } } static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu) { struct sk_buff *skb = hu->tx_skb; if (!skb) skb = hu->proto->dequeue(hu); else hu->tx_skb = NULL; return skb; } int hci_uart_tx_wakeup(struct hci_uart *hu) { struct tty_struct *tty = hu->tty; struct hci_dev *hdev = hu->hdev; struct sk_buff *skb; if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) { set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state); return 0; } BT_DBG(""); restart: clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state); while ((skb = hci_uart_dequeue(hu))) { int len; set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); len = tty->driver->write(tty, skb->data, skb->len); hdev->stat.byte_tx += len; skb_pull(skb, len); if (skb->len) { hu->tx_skb = skb; break; } hci_uart_tx_complete(hu, bt_cb(skb)->pkt_type); kfree_skb(skb); } if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state)) goto restart; clear_bit(HCI_UART_SENDING, &hu->tx_state); return 0; } /* ------- Interface to HCI layer ------ */ /* Initialize device */ static int hci_uart_open(struct hci_dev *hdev) { BT_DBG("%s %p", hdev->name, hdev); /* Nothing to do for UART driver */ set_bit(HCI_RUNNING, &hdev->flags); return 0; } /* Reset device */ static int hci_uart_flush(struct hci_dev *hdev) { struct hci_uart *hu = (struct hci_uart *) hdev->driver_data; struct tty_struct *tty = hu->tty; BT_DBG("hdev %p tty %p", hdev, tty); if (hu->tx_skb) { kfree_skb(hu->tx_skb); hu->tx_skb = NULL; } /* Flush any pending characters in the driver and discipline. */ tty_ldisc_flush(tty); if (tty->driver && tty->driver->flush_buffer) tty->driver->flush_buffer(tty); if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) hu->proto->flush(hu); return 0; } /* Close device */ static int hci_uart_close(struct hci_dev *hdev) { BT_DBG("hdev %p", hdev); if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags)) return 0; hci_uart_flush(hdev); return 0; } /* Send frames from HCI layer */ static int hci_uart_send_frame(struct sk_buff *skb) { struct hci_dev* hdev = (struct hci_dev *) skb->dev; struct tty_struct *tty; struct hci_uart *hu; if (!hdev) { BT_ERR("Frame for uknown device (hdev=NULL)"); return -ENODEV; } if (!test_bit(HCI_RUNNING, &hdev->flags)) return -EBUSY; hu = (struct hci_uart *) hdev->driver_data; tty = hu->tty; BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len); hu->proto->enqueue(hu, skb); hci_uart_tx_wakeup(hu); return 0; } static void hci_uart_destruct(struct hci_dev *hdev) { if (!hdev) return; BT_DBG("%s", hdev->name); kfree(hdev->driver_data); } /* ------ LDISC part ------ */ /* hci_uart_tty_open * * Called when line discipline changed to HCI_UART. * * Arguments: * tty pointer to tty info structure * Return Value: * 0 if success, otherwise error code */ static int hci_uart_tty_open(struct tty_struct *tty) { struct hci_uart *hu = (void *) tty->disc_data; BT_DBG("tty %p", tty); if (hu) return -EEXIST; if (!(hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL))) { BT_ERR("Can't allocate control structure"); return -ENFILE; } tty->disc_data = hu; hu->tty = tty; tty->receive_room = 65536; spin_lock_init(&hu->rx_lock); /* Flush any pending characters in the driver and line discipline. */ /* FIXME: why is this needed. Note don't use ldisc_ref here as the open path is before the ldisc is referencable */ if (tty->ldisc.flush_buffer) tty->ldisc.flush_buffer(tty); if (tty->driver && tty->driver->flush_buffer) tty->driver->flush_buffer(tty); return 0; } /* hci_uart_tty_close() * * Called when the line discipline is changed to something * else, the tty is closed, or the tty detects a hangup. */ static void hci_uart_tty_close(struct tty_struct *tty) { struct hci_uart *hu = (void *)tty->disc_data; BT_DBG("tty %p", tty); /* Detach from the tty */ tty->disc_data = NULL; if (hu) { struct hci_dev *hdev = hu->hdev; if (hdev) hci_uart_close(hdev); if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) { hu->proto->close(hu); hci_unregister_dev(hdev); hci_free_dev(hdev); } } } /* hci_uart_tty_wakeup() * * Callback for transmit wakeup. Called when low level * device driver can accept more send data. * * Arguments: tty pointer to associated tty instance data * Return Value: None */ static void hci_uart_tty_wakeup(struct tty_struct *tty) { struct hci_uart *hu = (void *)tty->disc_data; BT_DBG(""); if (!hu) return; clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); if (tty != hu->tty) return; if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) hci_uart_tx_wakeup(hu); } /* hci_uart_tty_receive() * * Called by tty low level driver when receive data is * available. * * Arguments: tty pointer to tty isntance data * data pointer to received data * flags pointer to flags for data * count count of received data in bytes * * Return Value: None */ static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, char *flags, int count) { struct hci_uart *hu = (void *)tty->disc_data; if (!hu || tty != hu->tty) return; if (!test_bit(HCI_UART_PROTO_SET, &hu->flags)) return; spin_lock(&hu->rx_lock); hu->proto->recv(hu, (void *) data, count); hu->hdev->stat.byte_rx += count; spin_unlock(&hu->rx_lock); if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) && tty->driver->unthrottle) tty->driver->unthrottle(tty); } static int hci_uart_register_dev(struct hci_uart *hu) { struct hci_dev *hdev; BT_DBG(""); /* Initialize and register HCI device */ hdev = hci_alloc_dev(); if (!hdev) { BT_ERR("Can't allocate HCI device"); return -ENOMEM; } hu->hdev = hdev; hdev->type = HCI_UART; hdev->driver_data = hu; hdev->open = hci_uart_open; hdev->close = hci_uart_close; hdev->flush = hci_uart_flush; hdev->send = hci_uart_send_frame; hdev->destruct = hci_uart_destruct; hdev->owner = THIS_MODULE; if (reset) set_bit(HCI_QUIRK_RESET_ON_INIT, &hdev->quirks); if (hci_register_dev(hdev) < 0) { BT_ERR("Can't register HCI device"); hci_free_dev(hdev); return -ENODEV; } return 0; } static int hci_uart_set_proto(struct hci_uart *hu, int id) { struct hci_uart_proto *p; int err; p = hci_uart_get_proto(id); if (!p) return -EPROTONOSUPPORT; err = p->open(hu); if (err) return err; hu->proto = p; err = hci_uart_register_dev(hu); if (err) { p->close(hu); return err; } return 0; } /* hci_uart_tty_ioctl() * * Process IOCTL system call for the tty device. * * Arguments: * * tty pointer to tty instance data * file pointer to open file object for device * cmd IOCTL command code * arg argument for IOCTL call (cmd dependent) * * Return Value: Command dependent */ static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file * file, unsigned int cmd, unsigned long arg) { struct hci_uart *hu = (void *)tty->disc_data; int err = 0; BT_DBG(""); /* Verify the status of the device */ if (!hu) return -EBADF; switch (cmd) { case HCIUARTSETPROTO: if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) { err = hci_uart_set_proto(hu, arg); if (err) { clear_bit(HCI_UART_PROTO_SET, &hu->flags); return err; } tty->low_latency = 1; } else return -EBUSY; break; case HCIUARTGETPROTO: if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) return hu->proto->id; return -EUNATCH; case HCIUARTGETDEVICE: if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) return hu->hdev->id; return -EUNATCH; default: err = n_tty_ioctl(tty, file, cmd, arg); break; }; return err; } /* * We don't provide read/write/poll interface for user space. */ static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file, unsigned char __user *buf, size_t nr) { return 0; } static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file, const unsigned char *data, size_t count) { return 0; } static unsigned int hci_uart_tty_poll(struct tty_struct *tty, struct file *filp, poll_table *wait) { return 0; } static int __init hci_uart_init(void) { static struct tty_ldisc hci_uart_ldisc; int err; BT_INFO("HCI UART driver ver %s", VERSION); /* Register the tty discipline */ memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc)); hci_uart_ldisc.magic = TTY_LDISC_MAGIC; hci_uart_ldisc.name = "n_hci"; hci_uart_ldisc.open = hci_uart_tty_open; hci_uart_ldisc.close = hci_uart_tty_close; hci_uart_ldisc.read = hci_uart_tty_read; hci_uart_ldisc.write = hci_uart_tty_write; hci_uart_ldisc.ioctl = hci_uart_tty_ioctl; hci_uart_ldisc.poll = hci_uart_tty_poll; hci_uart_ldisc.receive_buf = hci_uart_tty_receive; hci_uart_ldisc.write_wakeup = hci_uart_tty_wakeup; hci_uart_ldisc.owner = THIS_MODULE; if ((err = tty_register_ldisc(N_HCI, &hci_uart_ldisc))) { BT_ERR("HCI line discipline registration failed. (%d)", err); return err; } #ifdef CONFIG_BT_HCIUART_H4 h4_init(); #endif #ifdef CONFIG_BT_HCIUART_BCSP bcsp_init(); #endif return 0; } static void __exit hci_uart_exit(void) { int err; #ifdef CONFIG_BT_HCIUART_H4 h4_deinit(); #endif #ifdef CONFIG_BT_HCIUART_BCSP bcsp_deinit(); #endif /* Release tty registration of line discipline */ if ((err = tty_unregister_ldisc(N_HCI))) BT_ERR("Can't unregister HCI line discipline (%d)", err); } module_init(hci_uart_init); module_exit(hci_uart_exit); module_param(reset, bool, 0644); MODULE_PARM_DESC(reset, "Send HCI reset command on initialization"); MODULE_AUTHOR("Maxim Krasnyansky <maxk@qualcomm.com>, Marcel Holtmann <marcel@holtmann.org>"); MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION); MODULE_VERSION(VERSION); MODULE_LICENSE("GPL"); MODULE_ALIAS_LDISC(N_HCI);