Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755060AbcDRCxq (ORCPT ); Sun, 17 Apr 2016 22:53:46 -0400 Received: from mail-wm0-f67.google.com ([74.125.82.67]:34424 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932276AbcDRCxn (ORCPT ); Sun, 17 Apr 2016 22:53:43 -0400 From: Alexey Klimov To: linux-watchdog@vger.kernel.org Cc: linux@roeck-us.net, wim@iguana.be, oneukum@suse.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, yury.norov@gmail.com Subject: [PATCH v2] watchdog: add driver for StreamLabs USB watchdog device Date: Mon, 18 Apr 2016 03:53:36 +0100 Message-Id: <1460948016-5453-1-git-send-email-klimov.linux@gmail.com> X-Mailer: git-send-email 2.8.0.rc3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 12040 Lines: 390 This patch creates new driver that supports StreamLabs usb watchdog device. This device plugs into 9-pin usb header and connects to reset pin and reset button on common PC. USB commands used to communicate with device were reverse engineered using usbmon. Signed-off-by: Alexey Klimov --- Changes in v2: -- coding style cleanups -- turn some dev_err messages to dev_dbg -- reimplemented usb_streamlabs_wdt_command() to use loop -- re-worked disconnect routine -- rebased to 4.6-rc2, removed set_timeout method -- removed braces in .options field in streamlabs_wdt_indent -- mem allocation migrated to devm_kzalloc -- buffer for device struct moved inside main struct to avoid additional memory allocation -- removed watchdog_init_timeout() -- re-worked usb_streamlabs_wdt_{resume,suspend} -- removed struct usb_device pointer from main driver struct -- buffer preparation for communication migrated to cpu_to_le16() functions, also buffer is filled in as u16 elements to make this byteorder usable -- added stop command in usb_streamlabs_wdt_disconnect() drivers/watchdog/Kconfig | 15 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/streamlabs_wdt.c | 313 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 329 insertions(+) create mode 100644 drivers/watchdog/streamlabs_wdt.c diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index fb94765..130cf54 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1766,4 +1766,19 @@ config USBPCWATCHDOG Most people will say N. +config USB_STREAMLABS_WATCHDOG + tristate "StreamLabs USB watchdog driver" + depends on USB + ---help--- + This is the driver for the USB Watchdog dongle from StreamLabs. + If you correctly connect reset pins to motherboard Reset pin and + to Reset button then this device will simply watch your kernel to make + sure it doesn't freeze, and if it does, it reboots your computer + after a certain amount of time. + + + To compile this driver as a module, choose M here: the + module will be called streamlabs_wdt. + + Most people will say N. Say yes or M if you want to use such usb device. endif # WATCHDOG diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index feb6270..9d36929 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -25,6 +25,7 @@ obj-$(CONFIG_WDTPCI) += wdt_pci.o # USB-based Watchdog Cards obj-$(CONFIG_USBPCWATCHDOG) += pcwd_usb.o +obj-$(CONFIG_USB_STREAMLABS_WATCHDOG) += streamlabs_wdt.o # ALPHA Architecture diff --git a/drivers/watchdog/streamlabs_wdt.c b/drivers/watchdog/streamlabs_wdt.c new file mode 100644 index 0000000..3e34cd8 --- /dev/null +++ b/drivers/watchdog/streamlabs_wdt.c @@ -0,0 +1,313 @@ +/* + * StreamLabs USB Watchdog driver + * + * Copyright (c) 2016 Alexey Klimov + * + * This program is free software; you may 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. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * USB Watchdog device from Streamlabs + * http://www.stream-labs.com/products/devices/watchdog/ + * + * USB commands have been reverse engineered using usbmon. + */ + +#define DRIVER_AUTHOR "Alexey Klimov " +#define DRIVER_DESC "StreamLabs USB watchdog driver" +#define DRIVER_NAME "usb_streamlabs_wdt" + +MODULE_AUTHOR(DRIVER_AUTHOR); +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_LICENSE("GPL"); + +#define USB_STREAMLABS_WATCHDOG_VENDOR 0x13c0 +#define USB_STREAMLABS_WATCHDOG_PRODUCT 0x0011 + +/* + * one buffer is used for communication, however transmitted message is only + * 32 bytes long + */ +#define BUFFER_TRANSFER_LENGTH 32 +#define BUFFER_LENGTH 64 +#define USB_TIMEOUT 350 + +#define STREAMLABS_CMD_START 0xaacc +#define STREAMLABS_CMD_STOP 0xbbff + +#define STREAMLABS_WDT_MIN_TIMEOUT 1 +#define STREAMLABS_WDT_MAX_TIMEOUT 46 + +struct streamlabs_wdt { + struct watchdog_device wdt_dev; + struct usb_interface *intf; + + struct mutex lock; + u8 buffer[BUFFER_LENGTH]; +}; + +static bool nowayout = WATCHDOG_NOWAYOUT; + +/* + * This function is used to check if watchdog actually changed + * its state to disabled that is reported in first two bytes of response + * message. + */ +static int usb_streamlabs_wdt_check_stop(u16 *buf) +{ + if (buf[0] != cpu_to_le16(STREAMLABS_CMD_STOP)) + return -EINVAL; + + return 0; +} + +static int usb_streamlabs_wdt_validate_response(u8 *buf) +{ + /* + * If watchdog device understood the command it will acknowledge + * with values 1,2,3,4 at indexes 10, 11, 12, 13 in response message + * when response treated as 8bit message. + */ + if (buf[10] != 1 || buf[11] != 2 || buf[12] != 3 || buf[13] != 4) + return -EINVAL; + + return 0; +} + +static void usb_streamlabs_wdt_prepare_buf(u16 *buf, u16 cmd, + unsigned long timeout_msec) +{ + /* + * remaining elements expected to be zero everytime during + * communication + */ + buf[0] = cpu_to_le16(cmd); + buf[1] = cpu_to_le16(0x8000); + + buf[3] = cpu_to_le16(timeout_msec); + buf[5] = 0x0; + buf[6] = 0x0; +} + +static int usb_streamlabs_wdt_command(struct watchdog_device *wdt_dev, u16 cmd) +{ + struct streamlabs_wdt *streamlabs_wdt = watchdog_get_drvdata(wdt_dev); + struct usb_device *usbdev; + int retval; + int size; + unsigned long timeout_msec; + + int retry_counter = 10; /* how many times to re-send stop cmd */ + + mutex_lock(&streamlabs_wdt->lock); + + if (unlikely(!streamlabs_wdt->intf)) { + mutex_unlock(&streamlabs_wdt->lock); + return -ENODEV; + } + + usbdev = interface_to_usbdev(streamlabs_wdt->intf); + timeout_msec = wdt_dev->timeout * MSEC_PER_SEC; + + do { + usb_streamlabs_wdt_prepare_buf((u16 *) streamlabs_wdt->buffer, + cmd, timeout_msec); + /* send command to watchdog */ + retval = usb_interrupt_msg(usbdev, usb_sndintpipe(usbdev, 0x02), + streamlabs_wdt->buffer, BUFFER_TRANSFER_LENGTH, + &size, USB_TIMEOUT); + + if (retval || size != BUFFER_TRANSFER_LENGTH) { + dev_dbg(&streamlabs_wdt->intf->dev, + "error %i when submitting interrupt msg\n", + retval); + retval = -EIO; + goto out; + } + + /* and read response from watchdog */ + retval = usb_interrupt_msg(usbdev, usb_rcvintpipe(usbdev, 0x81), + streamlabs_wdt->buffer, BUFFER_LENGTH, + &size, USB_TIMEOUT); + + if (retval || size != BUFFER_LENGTH) { + dev_dbg(&streamlabs_wdt->intf->dev, + "error %i when receiving interrupt msg\n", + retval); + retval = -EIO; + goto out; + } + + /* check if watchdog actually acked/recognized command */ + retval = usb_streamlabs_wdt_validate_response(streamlabs_wdt->buffer); + if (retval) { + dev_dbg(&streamlabs_wdt->intf->dev, + "watchdog didn't ACK command!\n"); + goto out; + } + + /* + * Transition from enabled to disabled state in this device + * for stop command doesn't happen immediately. Usually, 2 or 3 + * (sometimes even 4) stop commands should be sent until + * watchdog answers 'I'm stopped!'. + * Retry only stop command if watchdog fails to answer correctly + * about its state. After 10 attempts go out and return error. + * We do not retry start command. + */ + } while (cmd != STREAMLABS_CMD_START + && usb_streamlabs_wdt_check_stop((u16 *) streamlabs_wdt->buffer) + && --retry_counter >= 0); + +out: + mutex_unlock(&streamlabs_wdt->lock); + return retry_counter > 0 ? retval : -EIO; +} + +static int usb_streamlabs_wdt_start(struct watchdog_device *wdt_dev) +{ + return usb_streamlabs_wdt_command(wdt_dev, STREAMLABS_CMD_START); +} + +static int usb_streamlabs_wdt_stop(struct watchdog_device *wdt_dev) +{ + return usb_streamlabs_wdt_command(wdt_dev, STREAMLABS_CMD_STOP); +} + +static const struct watchdog_info streamlabs_wdt_ident = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, + .identity = DRIVER_NAME, +}; + +static struct watchdog_ops usb_streamlabs_wdt_ops = { + .owner = THIS_MODULE, + .start = usb_streamlabs_wdt_start, + .stop = usb_streamlabs_wdt_stop, +}; + +static int usb_streamlabs_wdt_probe(struct usb_interface *intf, + const struct usb_device_id *id) +{ + struct usb_device *usbdev = interface_to_usbdev(intf); + struct streamlabs_wdt *streamlabs_wdt; + int retval; + + /* + * USB IDs of this device appear to be weird/unregistered. Hence, do + * an additional check on product and manufacturer. + * If there is similar device in the field with same values then + * there is stop command in probe() below that checks if the device + * behaves as a watchdog. + */ + if (usbdev->product && usbdev->manufacturer && + (strncmp(usbdev->product, "USBkit", 6) != 0 + || strncmp(usbdev->manufacturer, "STREAM LABS", 11) != 0)) + return -ENODEV; + + streamlabs_wdt = devm_kzalloc(&intf->dev, sizeof(struct streamlabs_wdt), + GFP_KERNEL); + if (!streamlabs_wdt) + return -ENOMEM; + + mutex_init(&streamlabs_wdt->lock); + + streamlabs_wdt->wdt_dev.info = &streamlabs_wdt_ident; + streamlabs_wdt->wdt_dev.ops = &usb_streamlabs_wdt_ops; + streamlabs_wdt->wdt_dev.timeout = STREAMLABS_WDT_MAX_TIMEOUT; + streamlabs_wdt->wdt_dev.max_timeout = STREAMLABS_WDT_MAX_TIMEOUT; + streamlabs_wdt->wdt_dev.min_timeout = STREAMLABS_WDT_MIN_TIMEOUT; + streamlabs_wdt->wdt_dev.parent = &intf->dev; + + streamlabs_wdt->intf = intf; + usb_set_intfdata(intf, &streamlabs_wdt->wdt_dev); + watchdog_set_drvdata(&streamlabs_wdt->wdt_dev, streamlabs_wdt); + watchdog_set_nowayout(&streamlabs_wdt->wdt_dev, nowayout); + + retval = usb_streamlabs_wdt_stop(&streamlabs_wdt->wdt_dev); + if (retval) + return retval; + + retval = watchdog_register_device(&streamlabs_wdt->wdt_dev); + if (retval) { + dev_err(&intf->dev, "failed to register watchdog device\n"); + return retval; + } + + dev_info(&intf->dev, "StreamLabs USB watchdog loaded.\n"); + + return 0; +} + + + +static int usb_streamlabs_wdt_suspend(struct usb_interface *intf, + pm_message_t message) +{ + struct streamlabs_wdt *streamlabs_wdt = usb_get_intfdata(intf); + + if (watchdog_active(&streamlabs_wdt->wdt_dev)) + return usb_streamlabs_wdt_stop(&streamlabs_wdt->wdt_dev); + + return 0; +} + +static int usb_streamlabs_wdt_resume(struct usb_interface *intf) +{ + struct streamlabs_wdt *streamlabs_wdt = usb_get_intfdata(intf); + + if (watchdog_active(&streamlabs_wdt->wdt_dev)) + return usb_streamlabs_wdt_start(&streamlabs_wdt->wdt_dev); + + return 0; +} + +static void usb_streamlabs_wdt_disconnect(struct usb_interface *intf) +{ + struct streamlabs_wdt *streamlabs_wdt = usb_get_intfdata(intf); + + usb_streamlabs_wdt_stop(&streamlabs_wdt->wdt_dev); + + mutex_lock(&streamlabs_wdt->lock); + usb_set_intfdata(intf, NULL); + streamlabs_wdt->intf = NULL; + mutex_unlock(&streamlabs_wdt->lock); + + watchdog_unregister_device(&streamlabs_wdt->wdt_dev); +} + +static struct usb_device_id usb_streamlabs_wdt_device_table[] = { + { USB_DEVICE(USB_STREAMLABS_WATCHDOG_VENDOR, USB_STREAMLABS_WATCHDOG_PRODUCT) }, + { } /* Terminating entry */ +}; + +MODULE_DEVICE_TABLE(usb, usb_streamlabs_wdt_device_table); + +static struct usb_driver usb_streamlabs_wdt_driver = { + .name = DRIVER_NAME, + .probe = usb_streamlabs_wdt_probe, + .disconnect = usb_streamlabs_wdt_disconnect, + .suspend = usb_streamlabs_wdt_suspend, + .resume = usb_streamlabs_wdt_resume, + .reset_resume = usb_streamlabs_wdt_resume, + .id_table = usb_streamlabs_wdt_device_table, +}; + +module_usb_driver(usb_streamlabs_wdt_driver); -- 2.8.0.rc3