From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F007F3F8ED8; Tue, 13 Oct 2026 11:38:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791891541; cv=none; b=fpVcLmiTL2LiutLdmPeeVkmnSFL/UukYc8X2CuWT31U6jXHCBYAhl8K9g7LW9ha5FCUX29DXdpT8rqqLoEQoFPJvBxozqkOVW/i95IBOPjLAtJVWdNmbjsfT2y/iQQtkgKqzNI3BqcFBtt0M6OdRhF0wtp0OqHIkIV6HulscF4w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791891541; c=relaxed/simple; bh=YFsUef0f38ac/+8b1qLSfSN9685amM3deilBErx/gTM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=e8Gk+Et0Xg451K+CJfr5jqJ42nrnDpiE/fA+2bqrC7eaRCIGHydeXGpKW3mXqLBeUoATa61GLwB4jK8orFeIpzCRnrRJxXBq3grkSsy7oriNXjiw6pdcR7GCZGVWdFQWGUtkjiDaYK39If2X72iUiPZI8HwVvLqlno5xiNqGpzs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ZkfFpE8K; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ZkfFpE8K" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F02111F00893; Tue, 13 Oct 2026 11:38:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1791891539; bh=P5s1qW3zZcChHW3VhOHAkmvlfucncjuOWhArdg/PEzw=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=ZkfFpE8KdXIvNqzBbwSpfzKEh9DQtukW1FykWQ77AlxRz5p5KOoVi7dAMNfyLVH9F 6z1uURP6uN/LCFu00SoJnh2nfNC+3BTELjZt8zfya4kplgHxHRPMbxzkAK5lFxyfxT gIU1FJhYQtqASy/bF3mQRuo15QWaHztjjFdQBhCo= Date: Tue, 13 Oct 2026 13:39:04 +0200 From: Greg Kroah-Hartman To: Adrian Ambrozewicz Cc: Donald Shannon , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Linus Walleij , Bartosz Golaszewski , Lee Jones , Pavel Machek , Andi Shyti , Mark Brown , Jiri Slaby , Corey Minyard , "Rafael J. Wysocki" , Len Brown , Jonathan Corbet , Ilpo =?iso-8859-1?Q?J=E4rvinen?= , Sakari Ailus , Hans de Goede , Lixu Zhang , Danilo Krummrich , Johan Hovold , Oliver Neukum , Quan Nguyen , Andrew Jeffery , linux-usb@vger.kernel.org, devicetree@vger.kernel.org, linux-gpio@vger.kernel.org, linux-leds@vger.kernel.org, linux-i2c@vger.kernel.org, linux-spi@vger.kernel.org, linux-serial@vger.kernel.org, openipmi-developer@lists.sourceforge.net, linux-acpi@vger.kernel.org, linux-doc@vger.kernel.org, driver-core@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH 00/11] Add NVIDIA LSTP USB adapter drivers Message-ID: <2026101310-scuttle-unison-d4c3@gregkh> References: <20261012-lstp-usb-adapter-v1-0-aambrozewicz@nvidia.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261012-lstp-usb-adapter-v1-0-aambrozewicz@nvidia.com> On Mon, Oct 12, 2026 at 08:35:58PM +0300, Adrian Ambrozewicz wrote: > This series adds drivers for the NVIDIA LSTP USB adapter: a USB core > driver and GPIO, LED, I2C, SPI, UART and BMC-side IPMI function drivers, > with their device tree bindings, an ACPI description document and the > sysfs ABI. > > What LSTP is > ------------ > > LSTP (Low-Speed Transport Protocol or Low-Speed Tunnelling Protocol) is > a vendor-specific USB interface (class 0xff, subclass 0x3f) that > multiplexes several low-speed "channels" over one pair of bulk > endpoints. It is implemented by NVIDIA's SMA, an MCU (0955:cf11), and > by other vendors' parts: two hub/bridge chips have it built in > (0424:4940, 174c:2214). Boards use it to > reach SPI flash, I2C sensors, GPIOs and LEDs, a UART and a host-to-BMC > IPMI path, on both BMCs and host systems. Also, if you really want to do this in a dynamic way, use greybus, as that is EXPLICITLY what it was designed for, and is patent-free (i.e. unencumbered, and we already support it in the kernel.) Please don't reinvent the wheel/spec just because no one did any prior-art research... thanks, greg k-h