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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A3DA0C04A95 for ; Sun, 25 Sep 2022 15:40:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231396AbiIYPk3 (ORCPT ); Sun, 25 Sep 2022 11:40:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37534 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229850AbiIYPk0 (ORCPT ); Sun, 25 Sep 2022 11:40:26 -0400 Received: from mail-pg1-x52d.google.com (mail-pg1-x52d.google.com [IPv6:2607:f8b0:4864:20::52d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0A13618E05; Sun, 25 Sep 2022 08:40:25 -0700 (PDT) Received: by mail-pg1-x52d.google.com with SMTP id s26so4522652pgv.7; Sun, 25 Sep 2022 08:40:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date; bh=ALf43tEt4uTY7t2ZG6Ao8BT7RErUJLGMqwWyM5uhgEc=; b=hqwPnnM/ypNQfn1GAU6crVglBMh7NBmkOrRMeMKH0gXTqXMYa5DFjsjfRf5m+R6r/e wjaP/7EpmEPJ61efUZ3KgwrZ6eKWxBBBmY8VPN9ctSySBRvtXpXd/WZeOHXChaTCjiDl YS7ydQy/7kvk/NLQMuYRdiq9e0B/BL9l9JiyH4WAweuar2ZX1zY03K2ToY6sQWjMXL3Z h7svrokrX4Rqm1Gf7QBy9+9GiOb9Lh5YqnJTQm3bcrXzQ6YeqiG3vxa9o4/ahkIolpzQ xx4yjcBIoitEZaLR/2f3M8tOWDy86puakGnE7rOmCVA8xXiOJZNyoIcbEzMN4bK4+GFo DrVQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date; bh=ALf43tEt4uTY7t2ZG6Ao8BT7RErUJLGMqwWyM5uhgEc=; b=hn6C5fK0WYpUXIGNguCmIGQOfeyVxkxuW2oEZ2YLWYsia9EyQ0/ICtyWrBmP0CUF4d Ei7FrTowf0RPjAQoOFfdjn2d95l6aTsbz4Iif/CGUd2eWokpbDKjBjOz8KjGmh6SuPrb NSqcIdFw5I3AExP9uLnCI2NeE72ItRactjDHzNlHMcW4ZWcCHR715lhjyhXOXvaoUntp JfujGFQRjyHpn7CUYisJcD9nUtmCTwa7mbpSzmMJ9tKbmI6F8gKTAOZBQk8ThJrCo7oS 0ujl1SHORczVFlP8K9ewtRLnHJxRRDzewZBODxVYRb1hfHkpyivA5gi0bwNAbPm8kVMs tuNQ== X-Gm-Message-State: ACrzQf3xh8I8w3WRMas6Dzu3F6jLUPqp5lNhFNapvfTYQUgOyNIB5j95 TrnxW2GvXgUPP4XULgCdoWY= X-Google-Smtp-Source: AMsMyM5qEgpsSBH0Cd3X5H1tJXymH6cgWhNuk88G9vgitj4eLEaGuYvD3kPzFZfzfeaTUToVZNfo8w== X-Received: by 2002:a63:191d:0:b0:434:4bb3:e016 with SMTP id z29-20020a63191d000000b004344bb3e016mr16522946pgl.133.1664120424520; Sun, 25 Sep 2022 08:40:24 -0700 (PDT) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id o67-20020a625a46000000b00554722eda37sm7790166pfb.0.2022.09.25.08.40.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 25 Sep 2022 08:40:23 -0700 (PDT) Sender: Guenter Roeck Date: Sun, 25 Sep 2022 08:40:22 -0700 From: Guenter Roeck To: Philippe Boos Cc: Wim Van Sebroeck , Neil Armstrong , Kevin Hilman , Jerome Brunet , Martin Blumenstingl , "open list:WATCHDOG DEVICE DRIVERS" , "moderated list:ARM/Amlogic Meson SoC support" , "open list:ARM/Amlogic Meson SoC support" , open list Subject: Re: [PATCH v2] watchdog: meson: keep running if already active Message-ID: <20220925154022.GA1758351@roeck-us.net> References: <20220801092150.4449-1-pboos@baylibre.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220801092150.4449-1-pboos@baylibre.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 01, 2022 at 11:21:50AM +0200, Philippe Boos wrote: > If the watchdog is already running (e.g.: started by bootloader) then > the kernel driver should keep the watchdog active but the amlogic driver > turns it off. > > Let the driver fix the clock rate if already active because we do not > know the previous timebase value. To avoid unintentional resetting we > temporarily set it to its maximum value. > > Then keep the enable bit if is was previously active. > > Signed-off-by: Philippe Boos > Reviewed-by: Jerome Brunet Reviewed-by: Guenter Roeck > --- > drivers/watchdog/meson_gxbb_wdt.c | 24 +++++++++++++++++++----- > 1 file changed, 19 insertions(+), 5 deletions(-) > > diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c > index 5a9ca10fbcfa..8be8fd9e5637 100644 > --- a/drivers/watchdog/meson_gxbb_wdt.c > +++ b/drivers/watchdog/meson_gxbb_wdt.c > @@ -146,6 +146,7 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev) > struct device *dev = &pdev->dev; > struct meson_gxbb_wdt *data; > int ret; > + u32 ctrl_reg; > > data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); > if (!data) > @@ -177,13 +178,26 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev) > data->wdt_dev.timeout = DEFAULT_TIMEOUT; > watchdog_set_drvdata(&data->wdt_dev, data); > > + ctrl_reg = readl(data->reg_base + GXBB_WDT_CTRL_REG) & > + GXBB_WDT_CTRL_EN; > + > + if (ctrl_reg) { > + /* Watchdog is running - keep it running but extend timeout > + * to the maximum while setting the timebase > + */ > + set_bit(WDOG_HW_RUNNING, &data->wdt_dev.status); > + meson_gxbb_wdt_set_timeout(&data->wdt_dev, > + GXBB_WDT_TCNT_SETUP_MASK / 1000); > + } > + > /* Setup with 1ms timebase */ > - writel(((clk_get_rate(data->clk) / 1000) & GXBB_WDT_CTRL_DIV_MASK) | > - GXBB_WDT_CTRL_EE_RESET | > - GXBB_WDT_CTRL_CLK_EN | > - GXBB_WDT_CTRL_CLKDIV_EN, > - data->reg_base + GXBB_WDT_CTRL_REG); > + ctrl_reg |= ((clk_get_rate(data->clk) / 1000) & > + GXBB_WDT_CTRL_DIV_MASK) | > + GXBB_WDT_CTRL_EE_RESET | > + GXBB_WDT_CTRL_CLK_EN | > + GXBB_WDT_CTRL_CLKDIV_EN; > > + writel(ctrl_reg, data->reg_base + GXBB_WDT_CTRL_REG); > meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout); > > watchdog_stop_on_reboot(&data->wdt_dev);