From patchwork Wed Jan 20 02:01:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Vasut X-Patchwork-Id: 12031269 X-Patchwork-Delegate: kuba@kernel.org 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 85AD2C433E0 for ; Wed, 20 Jan 2021 02:02:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 392F92245C for ; Wed, 20 Jan 2021 02:02:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731052AbhATCCY (ORCPT ); Tue, 19 Jan 2021 21:02:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33324 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730808AbhATCCR (ORCPT ); Tue, 19 Jan 2021 21:02:17 -0500 Received: from mail-out.m-online.net (mail-out.m-online.net [IPv6:2001:a60:0:28:0:1:25:1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F3072C0613CF for ; Tue, 19 Jan 2021 18:01:32 -0800 (PST) Received: from frontend01.mail.m-online.net (unknown [192.168.8.182]) by mail-out.m-online.net (Postfix) with ESMTP id 4DL7zt6NTJz1rsMZ; Wed, 20 Jan 2021 03:01:30 +0100 (CET) Received: from localhost (dynscan1.mnet-online.de [192.168.6.70]) by mail.m-online.net (Postfix) with ESMTP id 4DL7zt5jn4z1qrQG; Wed, 20 Jan 2021 03:01:30 +0100 (CET) X-Virus-Scanned: amavisd-new at mnet-online.de Received: from mail.mnet-online.de ([192.168.8.182]) by localhost (dynscan1.mail.m-online.net [192.168.6.70]) (amavisd-new, port 10024) with ESMTP id YvcG2Hlr_CFW; Wed, 20 Jan 2021 03:01:29 +0100 (CET) X-Auth-Info: Zm29SqeVxIM+6OHdJZE8KdM4cf0xlNI/BcF8ECwBumA= Received: from tr.lan (ip-89-176-112-137.net.upcbroadband.cz [89.176.112.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.mnet-online.de (Postfix) with ESMTPSA; Wed, 20 Jan 2021 03:01:29 +0100 (CET) From: Marek Vasut To: netdev@vger.kernel.org Cc: Marek Vasut , Andrew Lunn , Florian Fainelli , Jakub Kicinski , Michael Grzeschik , Paul Barker Subject: [PATCH net-next] net: dsa: microchip: Adjust reset release timing to match reference reset circuit Date: Wed, 20 Jan 2021 03:01:16 +0100 Message-Id: <20210120020116.576669-1-marex@denx.de> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org KSZ8794CNX datasheet section 8.0 RESET CIRCUIT describes recommended circuit for interfacing with CPU/FPGA reset consisting of 10k pullup resistor and 10uF capacitor to ground. This circuit takes ~100 mS to rise enough to release the reset. For maximum supply voltage VDDIO=3.3V VIH=2.0V R=10kR C=10uF that is VDDIO - VIH t = R * C * -ln( ------------- ) = 10000*0.00001*-(-0.93)=0.093 S VDDIO so we need ~95 mS for the reset to really de-assert, and then the original 100uS for the switch itself to come out of reset. Simply msleep() for 100 mS which fits the constraint with a bit of extra space. Fixes: 5b797980908a ("net: dsa: microchip: Implement recommended reset timing") Signed-off-by: Marek Vasut Cc: Andrew Lunn Cc: Florian Fainelli Cc: Jakub Kicinski Cc: Michael Grzeschik Cc: Paul Barker Reviewed-by: Florian Fainelli --- drivers/net/dsa/microchip/ksz_common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c index 489963664443..389abfd27770 100644 --- a/drivers/net/dsa/microchip/ksz_common.c +++ b/drivers/net/dsa/microchip/ksz_common.c @@ -400,7 +400,7 @@ int ksz_switch_register(struct ksz_device *dev, gpiod_set_value_cansleep(dev->reset_gpio, 1); usleep_range(10000, 12000); gpiod_set_value_cansleep(dev->reset_gpio, 0); - usleep_range(100, 1000); + msleep(100); } mutex_init(&dev->dev_mutex);