From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A7467C433ED for ; Tue, 30 Mar 2021 11:47:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 849EC61921 for ; Tue, 30 Mar 2021 11:47:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232067AbhC3LrD (ORCPT ); Tue, 30 Mar 2021 07:47:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38166 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231987AbhC3Lqi (ORCPT ); Tue, 30 Mar 2021 07:46:38 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E4C0C061764 for ; Tue, 30 Mar 2021 04:46:37 -0700 (PDT) Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=bjornoya.blackshift.org) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lRCpQ-0006G4-2d for linux-can@vger.kernel.org; Tue, 30 Mar 2021 13:46:36 +0200 Received: from dspam.blackshift.org (localhost [127.0.0.1]) by bjornoya.blackshift.org (Postfix) with SMTP id 650B0603E81 for ; Tue, 30 Mar 2021 11:46:20 +0000 (UTC) Received: from hardanger.blackshift.org (unknown [172.20.34.65]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by bjornoya.blackshift.org (Postfix) with ESMTPS id 10EF0603E13; Tue, 30 Mar 2021 11:46:09 +0000 (UTC) Received: from blackshift.org (localhost [::1]) by hardanger.blackshift.org (OpenSMTPD) with ESMTP id 9abfcafd; Tue, 30 Mar 2021 11:46:01 +0000 (UTC) From: Marc Kleine-Budde To: netdev@vger.kernel.org Cc: davem@davemloft.net, kuba@kernel.org, linux-can@vger.kernel.org, kernel@pengutronix.de, Torin Cooper-Bennun , Marc Kleine-Budde Subject: [net-next 19/39] can: m_can: m_can_chip_config(): enable and configure internal timestamps Date: Tue, 30 Mar 2021 13:45:39 +0200 Message-Id: <20210330114559.1114855-20-mkl@pengutronix.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210330114559.1114855-1-mkl@pengutronix.de> References: <20210330114559.1114855-1-mkl@pengutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-can@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-can@vger.kernel.org From: Torin Cooper-Bennun This is a prerequisite for transitioning the m_can driver to rx-offload, which works best with TX and RX timestamps. The timestamps provided by M_CAN are 16-bit, timed according to the nominal bit timing, and may be prescaled by a multiplier up to 16. We choose the highest prescalar so that the timestamp wraps every 2^20 bit times, or 209 ms at a bus speed of 5 Mbit/s. Timestamps will have a precision of 16 bit times. Link: https://lore.kernel.org/r/20210308102427.63916-3-torin@maxiluxsystems.com Signed-off-by: Torin Cooper-Bennun Signed-off-by: Marc Kleine-Budde --- drivers/net/can/m_can/m_can.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index 9f7cfe91f7ff..7df81e38b043 100644 --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -1135,6 +1135,7 @@ static int m_can_set_bittiming(struct net_device *dev) * - >= v3.1.x: TX FIFO is used * - configure mode * - setup bittiming + * - configure timestamp generation */ static void m_can_chip_config(struct net_device *dev) { @@ -1246,6 +1247,10 @@ static void m_can_chip_config(struct net_device *dev) /* set bittiming params */ m_can_set_bittiming(dev); + /* enable internal timestamp generation, with a prescalar of 16. The + * prescalar is applied to the nominal bit timing */ + m_can_write(cdev, M_CAN_TSCC, FIELD_PREP(TSCC_TCP_MASK, 0xf)); + m_can_config_endisable(cdev, false); if (cdev->ops->init) -- 2.30.2