From patchwork Sat Sep 17 03:05:34 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexey Klimov X-Patchwork-Id: 607300 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 41A11ECAAA1 for ; Sat, 17 Sep 2022 03:05:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229683AbiIQDFy (ORCPT ); Fri, 16 Sep 2022 23:05:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48310 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229541AbiIQDFx (ORCPT ); Fri, 16 Sep 2022 23:05:53 -0400 Received: from mail-qv1-xf30.google.com (mail-qv1-xf30.google.com [IPv6:2607:f8b0:4864:20::f30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 921646554F; Fri, 16 Sep 2022 20:05:48 -0700 (PDT) Received: by mail-qv1-xf30.google.com with SMTP id c6so18024404qvn.6; Fri, 16 Sep 2022 20:05:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date; bh=nT9TGyLVJBAxUFmrmFAz1FYx0wO/TBVpb4hszwcCiJw=; b=p+Dht6HXZyg/4SW6DbgfKjFgJMMdvVaSbaxweoN7ilajFOcSFclEirPZWeKgfxtmxO MCtWjpp0k1u9u/kWSQ5UgR/oNrBbFmVI8rC8VGwBCcK47VGYj3YUxjX09Zn1M4PQrvCm xf3+I7Xh/2XnXHwac3UbU86jNM2zm1vy7M2lgBukO8jaHB7/eynd1PXSw5RBuzTo+2Dt 70Rs1ukbxbGNEJ8zzHp6RMceTdC+OpQil6pKMeSMUTUjQ1llzBRpAx+QzFtpUeNdiphk kIggBHdsO/RP9HbhSuz5eP4BI0JqYIKoxJRAxhjWhFVs+Cq2jD01y31KNnUMXxAab110 hVUg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date; bh=nT9TGyLVJBAxUFmrmFAz1FYx0wO/TBVpb4hszwcCiJw=; b=kG4pffdZl6s2Scnp6niNZhvvbVBuBRafETa5n+Zq3Bv6pDtKOnlQ0hkXQ55qG+85P8 l3lhrK14+lg9ch+LAHFFy0Q/ccakKu2hOdlPBukwIL9gfYeLTTmhDj3ySLkGMsaE6RA/ t5uPhI7NbNj0+AoMN7xwm/vFvLTHA/W81FzuDt79dzZa2D4taT/IbuMK3dE+JHxTEHS5 G7mni/Ix8X0F0KHRUCZRWeqkcJMeuE68lY22vF0rjeG/Ta/dSHdGIk9AJJLUlBImS+o3 EeuJIIKJJkhjMpTInVz6zKHDBAwymYTrBov870eZFEJvO3flSyx69uSrJuAqaIsG339W ZXpQ== X-Gm-Message-State: ACrzQf1k7rTRf58FJbCSWqnz2u7/JxknQuiAeFovdSa621km7pPgKAUq V8DPX0Ilnk/4wVyHu5InKSGVkqNTvN9fOQ== X-Google-Smtp-Source: AMsMyM6fHhiRqyMYasRUu1J/hRfQCwqxid2eHyGLkrBsQYGR1VSikibBQ9rzNwJGgyVphEWyFUjKwQ== X-Received: by 2002:ad4:4eab:0:b0:4a2:8a8:6afc with SMTP id ed11-20020ad44eab000000b004a208a86afcmr6405729qvb.21.1663383947997; Fri, 16 Sep 2022 20:05:47 -0700 (PDT) Received: from localhost.localdomain ([2a01:4b00:9414:100:7d9f:4703:e9c:52c]) by smtp.gmail.com with ESMTPSA id d2-20020ac80602000000b0031f0b43629dsm6105937qth.23.2022.09.16.20.05.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 16 Sep 2022 20:05:47 -0700 (PDT) From: Alexey Klimov To: linux-watchdog@vger.kernel.org Cc: wim@linux-watchdog.org, linux@roeck-us.net, gregkh@linuxfoundation.org, 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 v6] watchdog: add driver for StreamLabs USB watchdog device Date: Sat, 17 Sep 2022 04:05:34 +0100 Message-Id: <20220917030534.363192-1-klimov.linux@gmail.com> X-Mailer: git-send-email 2.37.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@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 v5: -- moved to semaphore lock: down_killable()/up(); If I have to go with down_timeout() option, then I am not sure which timeout value to use, apart from maximum or current timeout from device; -- implemented {pre,post}_reset methods (thanks, Oliver!); -- back to the version where buffer is a part of struct streamlabs_wdt and now also ____cacheline_aligned; -- watchdog_start() in probe instead of watchdog_stop(); -- added watchdog_stop_on_reboot() in probe; -- other comments from Guenter. Previous version: https://lore.kernel.org/linux-usb/CALW4P+LmMJAm=3PWQfiEgYS7d_q0M0rdSJVhpZw9x9w3fQQMRA@mail.gmail.com/T/ MAINTAINERS | 6 + drivers/watchdog/Kconfig | 15 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/streamlabs_wdt.c | 412 ++++++++++++++++++++++++++++++ 4 files changed, 434 insertions(+) create mode 100644 drivers/watchdog/streamlabs_wdt.c -- 2.37.2 diff --git a/MAINTAINERS b/MAINTAINERS index 936490dcc97b..e56fd4d636d1 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -19480,6 +19480,12 @@ 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 9295492d24f7..8baf53fef3cc 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -2180,6 +2180,21 @@ 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 cdeb119e6e61..afc6fdc1b4d9 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..cc4f48f1fd36 --- /dev/null +++ b/drivers/watchdog/streamlabs_wdt.c @@ -0,0 +1,412 @@ +// 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 /* 350 ms */ + +#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 semaphore lock; + __le16 buffer[BUFFER_LENGTH] ____cacheline_aligned; +}; + +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 (retval) + return retval; + + if (size != BUFFER_TRANSFER_LENGTH) + return -EIO; + + return 0; +} + +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 (retval) + return retval; + + if (size != BUFFER_LENGTH) + return -EIO; + + return 0; +} + +/* + * 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; + + return usb_streamlabs_wdt_check_timeout(buf, timeout_msec); +} + +static void usb_streamlabs_wdt_prepare_buf(__le16 *buf, u16 cmd, + unsigned long timeout_msec) +{ + memset(buf, 0, BUFFER_LENGTH); + + buf[0] = cpu_to_le16(cmd); + buf[1] = cpu_to_le16(0x8000); + buf[3] = cpu_to_le16(timeout_msec); +} + +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; + + retval = down_killable(&streamlabs_wdt->lock); + if (retval) + return retval; + retval = __usb_streamlabs_wdt_cmd(streamlabs_wdt, cmd); + up(&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; + + sema_init(&streamlabs_wdt->lock, 1); + + 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); + watchdog_stop_on_reboot(&streamlabs_wdt->wdt_dev); + + retval = usb_streamlabs_wdt_start(&streamlabs_wdt->wdt_dev); + if (retval) + return -ENODEV; + set_bit(WDOG_HW_RUNNING, &streamlabs_wdt->wdt_dev.status); + + 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); + int retval; + + retval = down_killable(&streamlabs_wdt->lock); + if (retval) { + dev_warn(&intf->dev, + "failed to acquire semaphore in disconnect\n"); + return; + } + + /* + * 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; + up(&streamlabs_wdt->lock); +} + +static int usb_streamlabs_wdt_pre_reset(struct usb_interface *intf) +{ + struct streamlabs_wdt *streamlabs_wdt = usb_get_intfdata(intf); + int retval; + + retval = down_killable(&streamlabs_wdt->lock); + if (retval) { + dev_warn(&intf->dev, + "failed to acquire semaphore in pre_reset\n"); + return retval; + } + + if (watchdog_active(&streamlabs_wdt->wdt_dev)) { + retval = __usb_streamlabs_wdt_cmd(streamlabs_wdt, + STREAMLABS_CMD_STOP); + /* + * If ->pre_reset() callback fails, the ->disconnect() + * callback will be called. To let it work we should + * unlock semaphore here. + */ + if (retval) + up(&streamlabs_wdt->lock); + } + + return retval; +} + +static int usb_streamlabs_wdt_post_reset(struct usb_interface *intf) +{ + struct streamlabs_wdt *streamlabs_wdt = usb_get_intfdata(intf); + int retval = 0; + + /* FIXME: potential race here, watchdog_active() check is unreliable? */ + if (watchdog_active(&streamlabs_wdt->wdt_dev)) + retval = __usb_streamlabs_wdt_cmd(streamlabs_wdt, + STREAMLABS_CMD_START); + + up(&streamlabs_wdt->lock); + + return retval; +} + +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, + .pre_reset = usb_streamlabs_wdt_pre_reset, + .post_reset = usb_streamlabs_wdt_post_reset, + .id_table = usb_streamlabs_wdt_device_table, + .soft_unbind = 1, +}; + +module_usb_driver(usb_streamlabs_wdt_driver);