Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757212AbdGXXH3 (ORCPT ); Mon, 24 Jul 2017 19:07:29 -0400 Received: from fllnx210.ext.ti.com ([198.47.19.17]:25233 "EHLO fllnx210.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933079AbdGXXGS (ORCPT ); Mon, 24 Jul 2017 19:06:18 -0400 From: Franklin S Cooper Jr To: , , , , , , , , , , , CC: Franklin S Cooper Jr Subject: [PATCH v2 2/4] can: fixed-transceiver: Add documentation for CAN fixed transceiver bindings Date: Mon, 24 Jul 2017 18:05:19 -0500 Message-ID: <20170724230521.1436-3-fcooper@ti.com> X-Mailer: git-send-email 2.10.0 In-Reply-To: <20170724230521.1436-1-fcooper@ti.com> References: <20170724230521.1436-1-fcooper@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2001 Lines: 66 Add documentation to describe usage of the new fixed transceiver binding. This new binding is applicable for any CAN device therefore it exists as its own document. Signed-off-by: Franklin S Cooper Jr --- Version 2: Tweak commit message working Tweak wording for properties Drop unit addressing Give example if CAN-FD isn't supported .../bindings/net/can/fixed-transceiver.txt | 42 ++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 Documentation/devicetree/bindings/net/can/fixed-transceiver.txt diff --git a/Documentation/devicetree/bindings/net/can/fixed-transceiver.txt b/Documentation/devicetree/bindings/net/can/fixed-transceiver.txt new file mode 100644 index 0000000..dc7e3eb --- /dev/null +++ b/Documentation/devicetree/bindings/net/can/fixed-transceiver.txt @@ -0,0 +1,42 @@ +Fixed transceiver Device Tree binding +------------------------------ + +CAN transceiver typically limits the max speed in standard CAN and CAN FD +modes. Typically these limitations are static and the transceivers themselves +provide no way to detect this limitation at runtime. For this situation, +the "fixed-transceiver" node can be used. + +Properties: + +Optional: + max-arbitration-speed: a positive non 0 value that determines the max + speed that CAN can run in non CAN-FD mode or during the + arbitration phase in CAN-FD mode. + + max-data-speed: a positive non 0 value that determines the max data rate + that can be used in CAN-FD mode. A value of -1 implies + CAN-FD is not supported by the transceiver. + +Examples: + +Based on Texas Instrument's TCAN1042HGV CAN Transceiver + +m_can0 { + .... + fixed-transceiver { + max-arbitration-speed = <1000000>; + max-data-speed = <5000000>; + }; + ... +}; + +Based on a CAN Transceiver that doesn't support CAN-FD. Only needed if the +CAN IP supports CAN-FD but is using a transceiver that doesn't. + +m_can0 { + .... + fixed-transceiver { + max-data-speed = <(-1)>; + }; + ... +}; -- 2.10.0