From patchwork Mon Jul 25 03:06:05 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexey Klimov X-Patchwork-Id: 594045 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4A964C43334 for ; Mon, 25 Jul 2022 03:06:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229652AbiGYDGh (ORCPT ); Sun, 24 Jul 2022 23:06:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60672 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230005AbiGYDGP (ORCPT ); Sun, 24 Jul 2022 23:06:15 -0400 Received: from mail-wm1-x329.google.com (mail-wm1-x329.google.com [IPv6:2a00:1450:4864:20::329]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5F309E021; Sun, 24 Jul 2022 20:06:13 -0700 (PDT) Received: by mail-wm1-x329.google.com with SMTP id c22so5988829wmr.2; Sun, 24 Jul 2022 20:06:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=gOEP+E9vEvmvs8/MLAucoh0GM1fTWokr8r32cEEhGnA=; b=mYDvNxeTMr71SJxS+KOy2KPcVem7hK81JydJ9AiYjPuhDVroBIThLG1ricE3gio0nI W3ktsWbTeNGTSsAojvKBLqA6JR6EXXhOsL+/AuX4aLqncq9ZxlfQ67T+V2tle6CCmAXT vbLfBVkaSDC+2RbdV2u3R8VxVkOQkUc4bxor4fMjFummgcPWvYarzGUTKmnIe7P0+cll RyygBJYKwSPajEpI8WmUzkGnPNnnc3eGLTwy/7wTLkjVaTWzsSTkCCpPS6Igxv1+slur Kgem9VasY1SvW9cc1bHZ8nIJw1T1zSAqi9LwMosyA6qeVxVq6jFGpGIRqi2Kj9F05qP6 8KCQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=gOEP+E9vEvmvs8/MLAucoh0GM1fTWokr8r32cEEhGnA=; b=qnVQA1hn7czJVi91MQoTIrB3uuJ9DThnXzELXXQaJXHSDScnD7Hg5CpsczoGt5mnYS nUmE06nCm3tntDg0qQwiG0RJHRk/3tdA8AfGNW412iQuB3c6kUGA5fd4W9xKe9ubunIf zlAG3V2RT5PIIShhlFgMLQjPfsGK4SjpRiiZ1W0XkWrwomiPLTWn3W00aFHgkWjmQk2I Iie5k37zhzw4wuVmdTiaKzHAfEk/G6pwAXvcyCZdPg4dkV+phi9mX3V7nOPYx6KqUM+J TmUhWrRs9v2MooiAiz8kPpP2CzyHbAwqx9OaRoKWGy7jPPZk7uqLrYaQorF/AXTbRd8g idqQ== X-Gm-Message-State: AJIora9+HCKXzcpPNfA8cW6OPTg2yu7Rx27TzCh8DzawTI4Bys4e5xAp 5RLi7P5ZfTmhokUOyQSG858gXQ61jzvPyA== X-Google-Smtp-Source: AGRyM1tQqhrShSdxdB5nZ+zpWFy1pDSmnACwXGiN9SwTMwCM6ZhhCjfiyJE1Mx+x1BqGjMorF1EYKA== X-Received: by 2002:a05:600c:3ac7:b0:3a3:64c3:6ddf with SMTP id d7-20020a05600c3ac700b003a364c36ddfmr676407wms.105.1658718371634; Sun, 24 Jul 2022 20:06:11 -0700 (PDT) Received: from localhost.localdomain ([2a01:4b00:9414:100:70ae:aa59:3138:f63c]) by smtp.gmail.com with ESMTPSA id p10-20020adff20a000000b0021baf5e590dsm10523227wro.71.2022.07.24.20.06.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 24 Jul 2022 20:06:10 -0700 (PDT) From: Alexey Klimov To: linux-watchdog@vger.kernel.org Cc: wim@linux-watchdog.org, linux@roeck-us.net, oneukum@suse.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, atishp@rivosinc.com, atishp@atishpatra.org, yury.norov@gmail.com, aklimov@redhat.com, atomlin@redhat.com, klimov.linux@gmail.com Subject: [PATCH v5] watchdog: add driver for StreamLabs USB watchdog device Date: Mon, 25 Jul 2022 04:06:05 +0100 Message-Id: <20220725030605.1808710-1-klimov.linux@gmail.com> X-Mailer: git-send-email 2.36.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org Driver supports StreamLabs usb watchdog device. The device plugs into 9-pin usb header and connects to reset pins and reset button pins on desktop PC. USB commands used to communicate with device were reverse engineered using usbmon. Signed-off-by: Alexey Klimov --- Changes since v4: -- added more comments; -- added nowayout check in ->disconnect(); -- completely rework usb_streamlabs_wdt_cmd() -> __usb_streamlabs_wdt_cmd() and functions that handle validation of the response; -- usb sending and receiving msgs are moved to separate functions; -- added soft_unbind=1 flag in usb_driver struct to make it possible to send URBs in ->disconnect(); -- buffer is declared as __le16 now; -- made checkpatch.pl --strict happy; Previous version: https://lore.kernel.org/linux-watchdog/20220715234442.3910204-1-klimov.linux@gmail.com/ MAINTAINERS | 6 + drivers/watchdog/Kconfig | 15 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/streamlabs_wdt.c | 360 ++++++++++++++++++++++++++++++ 4 files changed, 382 insertions(+) create mode 100644 drivers/watchdog/streamlabs_wdt.c diff --git a/MAINTAINERS b/MAINTAINERS index 64379c699903..fb31c1823043 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -19190,6 +19190,12 @@ W: http://www.stlinux.com F: Documentation/networking/device_drivers/ethernet/stmicro/ F: drivers/net/ethernet/stmicro/stmmac/ +STREAMLABS USB WATCHDOG DRIVER +M: Alexey Klimov +L: linux-watchdog@vger.kernel.org +S: Maintained +F: drivers/watchdog/streamlabs_wdt.c + SUN3/3X M: Sam Creasey S: Maintained diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 32fd37698932..64b7f947b196 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -2171,6 +2171,21 @@ 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. + config KEEMBAY_WATCHDOG tristate "Intel Keem Bay SoC non-secure watchdog" depends on ARCH_KEEMBAY || (ARM64 && COMPILE_TEST) diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index c324e9d820e9..2d601da9b5bd 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -33,6 +33,7 @@ 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..f1130fe5559c --- /dev/null +++ b/drivers/watchdog/streamlabs_wdt.c @@ -0,0 +1,360 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * StreamLabs USB Watchdog driver + * + * Copyright (c) 2016-2017,2022 Alexey Klimov + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * USB Watchdog device from Streamlabs: + * https://www.stream-labs.com/products/devices/watch-dog/ + * + * 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 + +/* timeout 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; + /* Serialises usb communication with a device */ + struct mutex lock; + __le16 *buffer; +}; + +static bool nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +/* USB call wrappers to send and receive messages to/from the device. */ +static int usb_streamlabs_send_msg(struct usb_device *usbdev, __le16 *buf) +{ + int retval; + int size; + + retval = usb_interrupt_msg(usbdev, usb_sndintpipe(usbdev, 0x02), + buf, BUFFER_TRANSFER_LENGTH, + &size, USB_TIMEOUT); + + if (size != BUFFER_TRANSFER_LENGTH) + return -EIO; + + return retval; +} + +static int usb_streamlabs_get_msg(struct usb_device *usbdev, __le16 *buf) +{ + int retval; + int size; + + retval = usb_interrupt_msg(usbdev, usb_rcvintpipe(usbdev, 0x81), + buf, BUFFER_LENGTH, + &size, USB_TIMEOUT); + + if (size != BUFFER_LENGTH) + return -EIO; + + return retval; +} + +/* + * This function is used to check if watchdog timeout in the received buffer + * matches the timeout passed from watchdog subsystem. + */ +static int usb_streamlabs_wdt_check_timeout(__le16 *buf, unsigned long timeout) +{ + if (buf[3] != cpu_to_le16(timeout)) + return -EPROTO; + + return 0; +} + +static int usb_streamlabs_wdt_check_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 -EPROTO; + + return 0; +} + +/* + * This function is used to check if watchdog command in the received buffer + * matches the command passed to the device. + */ +static int usb_streamlabs_wdt_check_command(__le16 *buf, u16 cmd) +{ + if (buf[0] != cpu_to_le16(cmd)) + return -EPROTO; + + return 0; +} + +static int usb_streamlabs_wdt_validate_response(__le16 *buf, u16 cmd, + unsigned long timeout_msec) +{ + int retval; + + retval = usb_streamlabs_wdt_check_response((u8 *)buf); + if (retval) + return retval; + + retval = usb_streamlabs_wdt_check_command(buf, cmd); + if (retval) + return retval; + + retval = usb_streamlabs_wdt_check_timeout(buf, timeout_msec); + return retval; +} + +static void usb_streamlabs_wdt_prepare_buf(__le16 *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; + /* how many times to re-try getting the state of the device */ + unsigned int retry_counter = 10; + int retval; + + 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(wdt->buffer, cmd, timeout_msec); + + /* send command to watchdog */ + retval = usb_streamlabs_send_msg(usbdev, wdt->buffer); + if (retval) + return retval; + + /* + * Transition from one state to another in this device + * doesn't happen immediately, especially stopping the device + * is not observed on the first reading of the response. + * Plus to avoid potentially stale response message in the device + * we keep reading the state of the device until we see: + * -- that device recognised the sent command; + * -- the received state (started or stopped) matches the state + * that was requested; + * -- the timeout passed matches the timeout value read from + * the device. + * Keep retrying 10 times and if watchdog device doesn't respond + * correctly as expected we bail out and return an error. + */ + do { + retval = usb_streamlabs_get_msg(usbdev, wdt->buffer); + if (retval) + break; + + retval = usb_streamlabs_wdt_validate_response(wdt->buffer, cmd, + timeout_msec); + } while (retval && retry_counter--); + + return retry_counter ? retval : -EIO; +} + +static int usb_streamlabs_wdt_cmd(struct streamlabs_wdt *streamlabs_wdt, u16 cmd) +{ + int retval; + + mutex_lock(&streamlabs_wdt->lock); + retval = __usb_streamlabs_wdt_cmd(streamlabs_wdt, cmd); + mutex_unlock(&streamlabs_wdt->lock); + + return retval; +} + +static int usb_streamlabs_wdt_start(struct watchdog_device *wdt_dev) +{ + struct streamlabs_wdt *streamlabs_wdt = watchdog_get_drvdata(wdt_dev); + + return usb_streamlabs_wdt_cmd(streamlabs_wdt, STREAMLABS_CMD_START); +} + +static int usb_streamlabs_wdt_stop(struct watchdog_device *wdt_dev) +{ + struct streamlabs_wdt *streamlabs_wdt = watchdog_get_drvdata(wdt_dev); + + return usb_streamlabs_wdt_cmd(streamlabs_wdt, STREAMLABS_CMD_STOP); +} + +static const struct watchdog_info streamlabs_wdt_ident = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, + .identity = DRIVER_NAME, +}; + +static const 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 = devm_kzalloc(&intf->dev, 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) + return -ENODEV; + + retval = devm_watchdog_register_device(&intf->dev, + &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 driver 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); + + mutex_lock(&streamlabs_wdt->lock); + /* + * If disconnect happens via sysfs or on rmmod, then try to stop + * the watchdog. In case of physical detachment of the device this call + * will fail but we continue. + */ + if (!nowayout) + __usb_streamlabs_wdt_cmd(streamlabs_wdt, STREAMLABS_CMD_STOP); + /* Stop sending (new) messages to the device */ + streamlabs_wdt->intf = NULL; + mutex_unlock(&streamlabs_wdt->lock); +} + +static const 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, + .soft_unbind = 1, +}; + +module_usb_driver(usb_streamlabs_wdt_driver);