Return-Path: From: Rob Herring To: Greg Kroah-Hartman , Marcel Holtmann , Jiri Slaby , Sebastian Reichel , Arnd Bergmann , "Dr . H . Nikolaus Schaller" , Alan Cox Cc: Loic Poulain , Pavel Machek , Peter Hurley , NeilBrown , Linus Walleij , linux-bluetooth@vger.kernel.org, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH 6/6] bluetooth: hack up ldisc to use serio Date: Wed, 24 Aug 2016 18:24:37 -0500 Message-Id: <20160824232437.9446-8-robh@kernel.org> In-Reply-To: <20160824232437.9446-1-robh@kernel.org> References: <20160824232437.9446-1-robh@kernel.org> List-ID: This hacks up the BT ldisc in place to work as a serio driver. It will need refactoring into common, ldisc, and serio parts. It is working under QEMU to the point the driver can bind to a serio device via DT, register as a BT device, start sending out initial packets and receive data (typed at a terminal). Now I need to find a real device. Still need to figure out how to plumb a few tty things like TTY_DO_WRITE_WAKEUP bit handling and tty_unthrottle. Signed-off-by: Rob Herring --- drivers/bluetooth/hci_ldisc.c | 261 +++++++++++++++++------------------------- drivers/bluetooth/hci_uart.h | 3 + 2 files changed, 109 insertions(+), 155 deletions(-) diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c index dda9739..8149952 100644 --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -34,7 +34,9 @@ #include #include -#include +#include +#include +#include #include #include #include @@ -138,7 +140,7 @@ int hci_uart_tx_wakeup(struct hci_uart *hu) static void hci_uart_write_work(struct work_struct *work) { struct hci_uart *hu = container_of(work, struct hci_uart, write_work); - struct tty_struct *tty = hu->tty; + struct serio *serio = hu->serio; struct hci_dev *hdev = hu->hdev; struct sk_buff *skb; @@ -152,8 +154,8 @@ restart: while ((skb = hci_uart_dequeue(hu))) { int len; - set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); - len = tty->ops->write(tty, skb->data, skb->len); +// set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); + len = serio_write_buf(serio, skb->data, skb->len); hdev->stat.byte_tx += len; skb_pull(skb, len); @@ -215,17 +217,15 @@ static int hci_uart_open(struct hci_dev *hdev) static int hci_uart_flush(struct hci_dev *hdev) { struct hci_uart *hu = hci_get_drvdata(hdev); - struct tty_struct *tty = hu->tty; - BT_DBG("hdev %p tty %p", hdev, tty); + BT_DBG("hdev %p serio %p", hdev, hu->serio); 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); - tty_driver_flush_buffer(tty); + serio_write_flush(hu->serio); if (test_bit(HCI_UART_PROTO_READY, &hu->flags)) hu->proto->flush(hu); @@ -261,6 +261,8 @@ static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb) /* Flow control or un-flow control the device */ void hci_uart_set_flow_control(struct hci_uart *hu, bool enable) { + serio_set_flow_control(hu->serio, enable); +#if 0 struct tty_struct *tty = hu->tty; struct ktermios ktermios; int status; @@ -309,6 +311,7 @@ void hci_uart_set_flow_control(struct hci_uart *hu, bool enable) BT_DBG("Enabling hardware flow control: %s", status ? "failed" : "success"); } +#endif } void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed, @@ -317,7 +320,7 @@ void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed, hu->init_speed = init_speed; hu->oper_speed = oper_speed; } - +#if 0 void hci_uart_init_tty(struct hci_uart *hu) { struct tty_struct *tty = hu->tty; @@ -336,21 +339,13 @@ void hci_uart_init_tty(struct hci_uart *hu) /* tty_set_termios() return not checked as it is always 0 */ tty_set_termios(tty, &ktermios); } - +#endif void hci_uart_set_baudrate(struct hci_uart *hu, unsigned int speed) { - struct tty_struct *tty = hu->tty; - struct ktermios ktermios; - - ktermios = tty->termios; - ktermios.c_cflag &= ~CBAUD; - tty_termios_encode_baud_rate(&ktermios, speed, speed); - - /* tty_set_termios() return not checked as it is always 0 */ - tty_set_termios(tty, &ktermios); + int out_speed = serio_set_baudrate(hu->serio, speed); BT_DBG("%s: New tty speeds: %d/%d", hu->hdev->name, - tty->termios.c_ispeed, tty->termios.c_ospeed); + speed, out_speed); } static int hci_uart_setup(struct hci_dev *hdev) @@ -428,83 +423,6 @@ done: return 0; } -/* ------ 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; - - BT_DBG("tty %p", tty); - - /* Error if the tty has no write op instead of leaving an exploitable - hole */ - if (tty->ops->write == NULL) - return -EOPNOTSUPP; - - hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL); - if (!hu) { - BT_ERR("Can't allocate control structure"); - return -ENFILE; - } - - tty->disc_data = hu; - hu->tty = tty; - tty->receive_room = 65536; - - INIT_WORK(&hu->init_ready, hci_uart_init_work); - INIT_WORK(&hu->write_work, hci_uart_write_work); - - /* Flush any pending characters in the driver */ - 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 = tty->disc_data; - struct hci_dev *hdev; - - BT_DBG("tty %p", tty); - - /* Detach from the tty */ - tty->disc_data = NULL; - - if (!hu) - return; - - hdev = hu->hdev; - if (hdev) - hci_uart_close(hdev); - - cancel_work_sync(&hu->write_work); - - if (test_and_clear_bit(HCI_UART_PROTO_READY, &hu->flags)) { - if (hdev) { - if (test_bit(HCI_UART_REGISTERED, &hu->flags)) - hci_unregister_dev(hdev); - hci_free_dev(hdev); - } - hu->proto->close(hu); - } - clear_bit(HCI_UART_PROTO_SET, &hu->flags); - - kfree(hu); -} - /* hci_uart_tty_wakeup() * * Callback for transmit wakeup. Called when low level @@ -513,18 +431,18 @@ static void hci_uart_tty_close(struct tty_struct *tty) * Arguments: tty pointer to associated tty instance data * Return Value: None */ -static void hci_uart_tty_wakeup(struct tty_struct *tty) +static void hci_uart_serio_wakeup(struct serio *serio) { - struct hci_uart *hu = tty->disc_data; + struct hci_uart *hu = serio_get_drvdata(serio); BT_DBG(""); if (!hu) return; - clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); +// clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); - if (tty != hu->tty) + if (serio != hu->serio) return; if (test_bit(HCI_UART_PROTO_READY, &hu->flags)) @@ -543,16 +461,16 @@ static void hci_uart_tty_wakeup(struct tty_struct *tty) * * Return Value: None */ -static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, - char *flags, int count) +static int hci_uart_serio_receive(struct serio *serio, const u8 *data, + size_t count) { - struct hci_uart *hu = tty->disc_data; + struct hci_uart *hu = serio_get_drvdata(serio); - if (!hu || tty != hu->tty) - return; + if (!hu || serio != hu->serio) + return 0; if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) - return; + return 0; /* It does not need a lock here as it is already protected by a mutex in * tty caller @@ -562,7 +480,8 @@ static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, if (hu->hdev) hu->hdev->stat.byte_rx += count; - tty_unthrottle(tty); +// tty_unthrottle(tty); + return count; } static int hci_uart_register_dev(struct hci_uart *hu) @@ -595,7 +514,7 @@ static int hci_uart_register_dev(struct hci_uart *hu) hdev->flush = hci_uart_flush; hdev->send = hci_uart_send_frame; hdev->setup = hci_uart_setup; - SET_HCIDEV_DEV(hdev, hu->tty->dev); + SET_HCIDEV_DEV(hdev, &hu->serio->dev); if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags)) set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks); @@ -650,6 +569,7 @@ static int hci_uart_set_proto(struct hci_uart *hu, int id) return 0; } +#if 0 static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags) { @@ -733,56 +653,95 @@ static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file, return err; } +#endif -/* - * 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) +static int hci_uart_connect(struct serio *serio, struct serio_driver *drv) { - return 0; -} + int id, ret; + struct hci_uart *hu; + + BT_INFO("HCI UART driver ver %s", VERSION); + + id = (int)of_device_get_match_data(&serio->dev); + + hu = devm_kzalloc(&serio->dev, sizeof(struct hci_uart), GFP_KERNEL); + if (!hu) + return -ENFILE; + + serio_set_drvdata(serio, hu); + hu->serio = serio; + +// tty->receive_room = 65536; + + INIT_WORK(&hu->init_ready, hci_uart_init_work); + INIT_WORK(&hu->write_work, hci_uart_write_work); + + ret = serio_open(serio, drv); + if (ret) + return ret; + + set_bit(HCI_UART_PROTO_SET, &hu->flags); + ret = hci_uart_set_proto(hu, id); + if (ret) { + serio_close(serio); + return ret; + } + + /* Flush any pending characters in the driver */ +// tty_driver_flush_buffer(tty); -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 void hci_uart_disconnect(struct serio *serio) { - static struct tty_ldisc_ops hci_uart_ldisc; - int err; + struct hci_dev *hdev; + struct hci_uart *hu = serio_get_drvdata(serio); - BT_INFO("HCI UART driver ver %s", VERSION); + hdev = hu->hdev; + if (hdev) + hci_uart_close(hdev); - /* 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; - - err = tty_register_ldisc(N_HCI, &hci_uart_ldisc); - if (err) { - BT_ERR("HCI line discipline registration failed. (%d)", err); - return err; + cancel_work_sync(&hu->write_work); + + if (test_and_clear_bit(HCI_UART_PROTO_READY, &hu->flags)) { + if (hdev) { + if (test_bit(HCI_UART_REGISTERED, &hu->flags)) + hci_unregister_dev(hdev); + hci_free_dev(hdev); + } + hu->proto->close(hu); } + clear_bit(HCI_UART_PROTO_SET, &hu->flags); + + pr_info("hci_uart disconnect!!!\n"); + serio_close(serio); +} + + +static const struct of_device_id hci_uart_of_match[] = { + { .compatible = "loopback-uart", .data = (void *)HCI_UART_BCSP }, + {}, +}; +MODULE_DEVICE_TABLE(of, hci_uart_of_match); + +static struct serio_driver serio_hci_uart_drv = { + .driver = { + .name = "hci-uart", + .of_match_table = of_match_ptr(hci_uart_of_match), + }, + .description = "hci uart", + .write_wakeup = hci_uart_serio_wakeup, + .receive_buf = hci_uart_serio_receive, + .connect = hci_uart_connect, + .disconnect = hci_uart_disconnect, +}; +module_serio_driver(serio_hci_uart_drv); + +static int __init hci_uart_init(void) +{ #ifdef CONFIG_BT_HCIUART_H4 h4_init(); #endif @@ -816,8 +775,6 @@ static int __init hci_uart_init(void) static void __exit hci_uart_exit(void) { - int err; - #ifdef CONFIG_BT_HCIUART_H4 h4_deinit(); #endif @@ -845,11 +802,6 @@ static void __exit hci_uart_exit(void) #ifdef CONFIG_BT_HCIUART_AG6XX ag6xx_deinit(); #endif - - /* Release tty registration of line discipline */ - err = tty_unregister_ldisc(N_HCI); - if (err) - BT_ERR("Can't unregister HCI line discipline (%d)", err); } module_init(hci_uart_init); @@ -859,4 +811,3 @@ MODULE_AUTHOR("Marcel Holtmann "); MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION); MODULE_VERSION(VERSION); MODULE_LICENSE("GPL"); -MODULE_ALIAS_LDISC(N_HCI); diff --git a/drivers/bluetooth/hci_uart.h b/drivers/bluetooth/hci_uart.h index 839bad1..c48dddc 100644 --- a/drivers/bluetooth/hci_uart.h +++ b/drivers/bluetooth/hci_uart.h @@ -73,8 +73,11 @@ struct hci_uart_proto { struct sk_buff *(*dequeue)(struct hci_uart *hu); }; +struct serio; + struct hci_uart { struct tty_struct *tty; + struct serio *serio; struct hci_dev *hdev; unsigned long flags; unsigned long hdev_flags; -- 2.9.3