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 <klimov.linux@xxxxxxxxx> --- Changes in v3: -- coding style cleanups and rebase; -- buffer is allocated with separate allocation; -- adding comments about max/min limits; -- rework start/stop commands implementation; -- fix first if-check in probe() function; Previous version: https://www.spinics.net/lists/linux-watchdog/msg09092.html drivers/watchdog/Kconfig | 16 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/streamlabs_wdt.c | 321 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 338 insertions(+) create mode 100644 drivers/watchdog/streamlabs_wdt.c diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index acb00b53a520..6a2195d8cc5c 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1852,6 +1852,22 @@ 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. + comment "Watchdog Pretimeout Governors" config WATCHDOG_PRETIMEOUT_GOV diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 0c3d35e3c334..d4a61222ccd2 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -31,6 +31,7 @@ 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 000000000000..4442d053d9f7 --- /dev/null +++ b/drivers/watchdog/streamlabs_wdt.c @@ -0,0 +1,321 @@ +/* + * StreamLabs USB Watchdog driver + * + * Copyright (c) 2016-2017 Alexey Klimov <klimov.linux@xxxxxxxxx> + * + * 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 <linux/errno.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/usb.h> +#include <linux/watchdog.h> +#include <asm/byteorder.h> + +/* + * USB Watchdog device from Streamlabs: + * https://www.stream-labs.com/en/catalog/?cat_id=1203&item_id=323 + * + * USB commands have been reverse engineered using usbmon. + */ + +#define DRIVER_AUTHOR "Alexey Klimov <klimov.linux@xxxxxxxxx>" +#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 + +/* timeouts values are taken from windows program */ +#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; +}; + +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_cmd(struct streamlabs_wdt *wdt, u16 cmd) +{ + struct usb_device *usbdev; + unsigned long timeout_msec; + int retval; + int size; + + if (unlikely(!wdt->intf)) + return -ENODEV; + + usbdev = interface_to_usbdev(wdt->intf); + timeout_msec = wdt->wdt_dev.timeout * MSEC_PER_SEC; + + usb_streamlabs_wdt_prepare_buf((u16 *) wdt->buffer, cmd, timeout_msec); + + /* send command to watchdog */ + retval = usb_interrupt_msg(usbdev, usb_sndintpipe(usbdev, 0x02), + wdt->buffer, BUFFER_TRANSFER_LENGTH, + &size, USB_TIMEOUT); + if (retval) + return retval; + + if (size != BUFFER_TRANSFER_LENGTH) + return -EIO; + + /* and read response from watchdog */ + retval = usb_interrupt_msg(usbdev, usb_rcvintpipe(usbdev, 0x81), + wdt->buffer, BUFFER_LENGTH, + &size, USB_TIMEOUT); + if (retval) + return retval; + + if (size != BUFFER_LENGTH) + return -EIO; + + /* check if watchdog actually acked/recognized command */ + return usb_streamlabs_wdt_validate_response(wdt->buffer); +} + +static int usb_streamlabs_wdt_stop_cmd(struct streamlabs_wdt *wdt) +{ + int retry_counter = 10; /* how many times to re-send stop cmd */ + int retval; + + /* + * 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. + */ + + do { + retval = usb_streamlabs_wdt_cmd(wdt, STREAMLABS_CMD_STOP); + if (retval) + break; + + retval = usb_streamlabs_wdt_check_stop((u16 *) wdt->buffer); + + } while (retval && --retry_counter >= 0); + + return retry_counter > 0 ? retval : -EIO; +} + +static int usb_streamlabs_wdt_start(struct watchdog_device *wdt_dev) +{ + struct streamlabs_wdt *streamlabs_wdt = watchdog_get_drvdata(wdt_dev); + int retval; + + mutex_lock(&streamlabs_wdt->lock); + retval = usb_streamlabs_wdt_cmd(streamlabs_wdt, STREAMLABS_CMD_START); + mutex_unlock(&streamlabs_wdt->lock); + + return retval; +} + +static int usb_streamlabs_wdt_stop(struct watchdog_device *wdt_dev) +{ + struct streamlabs_wdt *streamlabs_wdt = watchdog_get_drvdata(wdt_dev); + int retval; + + mutex_lock(&streamlabs_wdt->lock); + retval = usb_streamlabs_wdt_stop_cmd(streamlabs_wdt); + mutex_unlock(&streamlabs_wdt->lock); + + return retval; +} + +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) + || strncmp(usbdev->manufacturer, "STREAM LABS", 11)) + return -ENODEV; + + streamlabs_wdt = devm_kzalloc(&intf->dev, sizeof(struct streamlabs_wdt), + GFP_KERNEL); + if (!streamlabs_wdt) + return -ENOMEM; + + streamlabs_wdt->buffer = kzalloc(BUFFER_LENGTH, GFP_KERNEL); + if (!streamlabs_wdt->buffer) + 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) + goto free_buf; + + retval = watchdog_register_device(&streamlabs_wdt->wdt_dev); + if (retval) { + dev_err(&intf->dev, "failed to register watchdog device\n"); + goto free_buf; + } + + dev_info(&intf->dev, "StreamLabs USB watchdog loaded.\n"); + return 0; + +free_buf: + kfree(streamlabs_wdt->buffer); + return retval; +} + +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); + + mutex_lock(&streamlabs_wdt->lock); + usb_streamlabs_wdt_stop_cmd(streamlabs_wdt); + 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); -- 2.11.0 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
