From patchwork Thu May 2 18:27:53 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Fritz X-Patchwork-Id: 794323 Received: from fritzc.com (mail.fritzc.com [213.160.72.247]) (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 7A3A016FF58; Thu, 2 May 2024 18:29:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.160.72.247 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714674545; cv=none; b=oOUyZ9Q5bN+mHRbgsyrVggz34cUsWNKOPW88QpRzY1hWdRAvgelO3Z35Y4Z/hMunr0lQAAh/978AcdWlR0RYnVCPs/LWiv0c2fYZ/HdNADkUQZv3NADStrMhKQdrW82qALgRhwX18JPt1jFmX2vAtTPQGl5yTIP8JFv5XrmHAcA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714674545; c=relaxed/simple; bh=bnxHFSagL46w7XbVxtnSsoB1K8velCEt+qKIdqjJ40U=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=aq4KbZ82WwKPWpux5xuYI0UcltAv7lhg3b+ecbE2Qxv0csf2p11DybsMoGWIDtlSzAW35fJMGXHNnvN/WGbyCiAzcGYoTQIcyS0KyG8PZFa16ReAiiu5F/6W9a+2z7YEuZaKcc5JK2uVsdQhVNQ/zitkUOXGqtS4Leu3dmPknYM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=hexdev.de; spf=pass smtp.mailfrom=hexdev.de; dkim=pass (1024-bit key) header.d=fritzc.com header.i=@fritzc.com header.b=iSusF1h6; arc=none smtp.client-ip=213.160.72.247 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=hexdev.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=hexdev.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=fritzc.com header.i=@fritzc.com header.b="iSusF1h6" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=fritzc.com; s=dkim; h=Content-Transfer-Encoding:MIME-Version:Message-Id:Date:Subject:Cc: To:From:Sender:Reply-To:Content-Type:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: In-Reply-To:References:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=SFeuWKG1NuiH9JJ+7DAZwk0AtFUdomMCUxtm6A1N67c=; b=iSusF1h6bvFgTQp8tzkuQTA6iD V6HkPmroB4QC4rmHM3Z2dpE8rXGSZqerC6RPIyDJtF63W2mBjeD63k8zdJ9l8v0iASivLCXvLBcTa h6uefJu0k7bwgOx6o9+2EQcp/Uiw+OLBRxrFfHv+9Tr+1hQ7BNj75mmgRR0+XCyN2508=; Received: from 127.0.0.1 by fritzc.com with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim latest) (envelope-from ) id 1s2bAq-001ZbZ-0Q; Thu, 02 May 2024 20:28:52 +0200 From: Christoph Fritz To: Jiri Slaby , Oliver Hartkopp , Marc Kleine-Budde , Vincent Mailhol , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Jiri Kosina , Benjamin Tissoires , Greg Kroah-Hartman , Sebastian Reichel , Linus Walleij Cc: Andreas Lauser , Jonathan Corbet , Pavel Pisa , linux-can@vger.kernel.org, netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-input@vger.kernel.org, linux-serial@vger.kernel.org Subject: [PATCH v3 00/11] LIN Bus support for Linux Date: Thu, 2 May 2024 20:27:53 +0200 Message-Id: <20240502182804.145926-1-christoph.fritz@hexdev.de> X-Mailer: git-send-email 2.39.2 Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 This series is introducing basic Local Interconnect Network (LIN) (ISO 17987) [0] support to the Linux kernel, along with two drivers that make use of it: An advanced USB adapter and a lightweight serdev driver (for UARTs equipped with a LIN transceiver). The LIN bus is common in the automotive industry for connecting low-level devices like side mirrors, seats, ambient lights, etc. The LIN bus is a lower-cost bus system with a subset of features of CAN. Its earlier specification (before ISO) is publicly accessible [1]. This series of patches follows up on a discussion initiated by an RFC patch series [2]. The core of this series is the first patch, which implements the CAN_LIN glue driver. It basically utilizes the CAN interface on one side and for device drivers on the other side it creates a rx() function and several callbacks. This approach is non-invasive, as LIN frames (nearly identical to CAN frames) are just treated as a special case of CAN frames. This approach eliminates the need for a separate API for LIN, allowing the use of existing CAN tools, including the CAN broadcast manager. For the responder part of LIN, when a device responds to a controller request, it can reply on up to LIN its 64 possible IDs (0...63) with a maximum of 8 bytes payload. The response must be sent relatively quickly, so offloading is used (which is used by most devices anyway). Devices that do not support offloading (like the lightweight serdev) handle the list of responses in the driver on a best-effort basis. The CAN broadcast manager (bcm) makes a good interface for the LIN userland interface, bcm is therefore enhanced to handle the configuration of these offload RX frames, so that the device can handle the response on its own. As a basic alternative, a sysfs file per LIN identifier gets also introduced. The USB device driver for the hexLIN [3] adapter uses the HID protocol and is located in the drivers/hid directory. Which is a bit uncommon for a CAN device, but this is a LIN device and mainly a hid driver. The other driver, the UART lin-serdev driver requires support for break detection, this is addressed by two serdev patches. The lin-serdev driver has been tested on an ARM SoC, on its uart (uart-pl011) an adapter board (hexLIN-tty [4]) has been used. As a sidenote, in that tty serial driver (amba-pl011.c) it was necessary to disable DMA_ENGINE to accurately detect breaks [5]. The functions for generating LIN-Breaks and checksums, originally from a line discipline driver named sllin [6], have been adopted into the lin-serdev driver. To make use of the LIN mode configuration (commander or responder) option, a patch for iproute2 [7] has been made. The lin-utils [8] provide userland tools for reference, testing, and evaluation. These utilities are currently separate but may potentially be integrated into can-utils in the future. [0]: https://en.wikipedia.org/wiki/Local_Interconnect_Network [1]: https://www.lin-cia.org/fileadmin/microsites/lin-cia.org/resources/documents/LIN_2.2A.pdf [2]: https://lwn.net/Articles/916049/ [3]: https://hexdev.de/hexlin [4]: https://hexdev.de/hexlin#tty [5]: https://github.com/raspberrypi/linux/issues/5985 [6]: https://github.com/lin-bus/linux-lin/blob/master/sllin/sllin.c [7]: https://github.com/ch-f/iproute2/tree/lin-feature [8]: https://github.com/ch-f/lin-utils Changes in v3: - drop unneccessary mutex_lock/unlock and _destroy() in hexlin - add Kconfig depends for HID_MCS_HEXDEV - simplify reset retry in hexlin - simplify hid driver init - fix dt-bindings and its commit message - adapt and reorder includes - use unsigned long instead of ulong - use macro USEC_PER_SEC in linser_derive_timings() - drop goto in linser_tx_frame_as_responder() and use unlock+return - simplify linser_pop_fifo() by using kfifo_skip() - squash [PATCH v2 08/12] can: lin: Add special frame id for rx... Changes in v2: - add open/stop functions to also address teardown issues - adapt dt-bindings description and add hexdev - use 'unsigned int' instead of 'uint' - add and adapt macros - address review comments Christoph Fritz (11): can: Add LIN bus as CAN abstraction HID: hexLIN: Add support for USB LIN bus adapter tty: serdev: Add flag buffer aware receive_buf_fp() tty: serdev: Add method to enable break flags dt-bindings: vendor-prefixes: Add hexDEV dt-bindings: net/can: Add serial (serdev) LIN adapter can: Add support for serdev LIN adapters can: bcm: Add LIN answer offloading for responder mode can: lin: Handle rx offload config frames can: lin: Support setting LIN mode HID: hexLIN: Implement ability to update lin mode .../bindings/net/can/hexdev,lin-serdev.yaml | 32 + .../devicetree/bindings/vendor-prefixes.yaml | 2 + drivers/hid/Kconfig | 19 + drivers/hid/Makefile | 1 + drivers/hid/hid-hexdev-hexlin.c | 622 ++++++++++++++++++ drivers/hid/hid-ids.h | 1 + drivers/hid/hid-quirks.c | 3 + drivers/net/can/Kconfig | 26 + drivers/net/can/Makefile | 2 + drivers/net/can/lin-serdev.c | 500 ++++++++++++++ drivers/net/can/lin.c | 562 ++++++++++++++++ drivers/tty/serdev/core.c | 11 + drivers/tty/serdev/serdev-ttyport.c | 19 +- include/linux/serdev.h | 19 +- include/net/lin.h | 99 +++ include/uapi/linux/can/bcm.h | 5 +- include/uapi/linux/can/netlink.h | 2 + net/can/bcm.c | 74 ++- 18 files changed, 1993 insertions(+), 6 deletions(-) create mode 100644 Documentation/devicetree/bindings/net/can/hexdev,lin-serdev.yaml create mode 100644 drivers/hid/hid-hexdev-hexlin.c create mode 100644 drivers/net/can/lin-serdev.c create mode 100644 drivers/net/can/lin.c create mode 100644 include/net/lin.h