From patchwork Sun Nov 7 20:29:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sam Protsenko X-Patchwork-Id: 517850 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 140F8C433FE for ; Sun, 7 Nov 2021 20:30:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 01D3461374 for ; Sun, 7 Nov 2021 20:30:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236588AbhKGUdR (ORCPT ); Sun, 7 Nov 2021 15:33:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55570 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236473AbhKGUc7 (ORCPT ); Sun, 7 Nov 2021 15:32:59 -0500 Received: from mail-lj1-x234.google.com (mail-lj1-x234.google.com [IPv6:2a00:1450:4864:20::234]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D6BBBC061A0E for ; Sun, 7 Nov 2021 12:30:03 -0800 (PST) Received: by mail-lj1-x234.google.com with SMTP id i26so25467900ljg.7 for ; Sun, 07 Nov 2021 12:30:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=cYPbwCTdXSeLj2E8hNZ5xJvTX/oX1QKrup+rCI0n0GU=; b=l7XIsIat7cITBgnm4maENgKMC+Y7J7fJ/mK/sH2dl3eA3h4R/EeX/SuFgaSEJxaJxr B/94BP9ZRfWomvUvwJc1KeJJ8jFd2s32fCyHr8AgLjvXZExUqOP7hDbuzWIsdjlURt13 qLPti768pihZbETdBk9U0f8byDfRE2UcsNH5s4OAQ5fgi7wy9Hx8bzXlEbarj+03/rwN buxJ+oHffolblZ7ORH24pah1AhHVWUz+z8Mqh/obQyn88ao9Efc2f9iRqyFkEVneMd5I jM+qBnv2Tz7SikrDz6SgI4nazYLMpbf3llvvf/gmHC2mB9L4RlvhliwCugycZWUEY4so +fKQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=cYPbwCTdXSeLj2E8hNZ5xJvTX/oX1QKrup+rCI0n0GU=; b=IKU8zbkXvxeQe5+6l1D9+QNr9b5zf5sj/1CSW+tsj7hlWjr/pQsWUmj7wtRNg7qVF9 cb9P8JmpkteGvYYJClavveMbXhKzVhmA0/+GcZ5nYXSHEj4yKuAIC0vTphSbenflBAPW /e1ZVxwPtR3uBxNns3OZF1JI484IDe1o/Vyaonp2wMFbySsJ6IkUvBToiQ2QChOPFvcT w8ey7cm9CIBQFp5QegDjR/bJNL57IY5jE3QFIKGz1qeX/36Mbdt2ZteRVnqKxMSxOEVT BNzgasVCgojn9WS80j74yi+otq9nodkJfvdMDy/tShlh77t+vbSxmkXJ7wJ/wyH4W/g3 FdUA== X-Gm-Message-State: AOAM532qRaotB//42VYd5fqej+cobrLSShqSsnTkL2VcwzzfJpvDOxWP r2G9DhvamTh0uHrxRyRp7ty09aWfuwTPr1d0 X-Google-Smtp-Source: ABdhPJwTu42tk2TANGEmYJGt/w4gPIfSQ4+LZa/SlLrThYgnXPaXbWuuGN+wsh0Z9MIecE13uJhsXg== X-Received: by 2002:a05:651c:1605:: with SMTP id f5mr74693331ljq.232.1636317002197; Sun, 07 Nov 2021 12:30:02 -0800 (PST) Received: from localhost ([31.134.121.151]) by smtp.gmail.com with ESMTPSA id 13sm1571159lfq.285.2021.11.07.12.30.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 07 Nov 2021 12:30:01 -0800 (PST) From: Sam Protsenko To: Wim Van Sebroeck , Guenter Roeck , Rob Herring , Krzysztof Kozlowski Cc: linux-watchdog@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org Subject: [PATCH v3 10/12] watchdog: s3c2410: Support separate source clock Date: Sun, 7 Nov 2021 22:29:41 +0200 Message-Id: <20211107202943.8859-11-semen.protsenko@linaro.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211107202943.8859-1-semen.protsenko@linaro.org> References: <20211107202943.8859-1-semen.protsenko@linaro.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org Right now all devices supported in the driver have the single clock: it acts simultaneously as a bus clock (providing register interface clocking) and source clock (driving watchdog counter). Some newer Exynos chips, like Exynos850, have two separate clocks for that. In that case two clocks will be passed to the driver from the resource provider, e.g. Device Tree. Provide necessary infrastructure to support that case: - use source clock's rate for all timer related calculations - use bus clock to gate/ungate the register interface All devices that use the single clock are kept intact: if only one clock is passed from Device Tree, it will be used for both purposes as before. Signed-off-by: Sam Protsenko Reviewed-by: Guenter Roeck --- Changes in v3: - Removed has_src_clk field: clk framework can handle NULL clk; added s3c2410wdt_get_freq() function instead, to figure out which clock to use for getting the rate Changes in v2: - Reworded commit message to be more formal - Used separate "has_src_clk" trait to tell if source clock is present - Renamed clock variables to match their purpose - Removed caching source clock rate, obtaining it in place each time instead - Renamed err labels for more consistency drivers/watchdog/s3c2410_wdt.c | 56 +++++++++++++++++++++++++--------- 1 file changed, 41 insertions(+), 15 deletions(-) diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c index f211be8bf976..f31bc765a8a5 100644 --- a/drivers/watchdog/s3c2410_wdt.c +++ b/drivers/watchdog/s3c2410_wdt.c @@ -153,7 +153,8 @@ struct s3c2410_wdt_variant { struct s3c2410_wdt { struct device *dev; - struct clk *clock; + struct clk *bus_clk; /* for register interface (PCLK) */ + struct clk *src_clk; /* for WDT counter */ void __iomem *reg_base; unsigned int count; spinlock_t lock; @@ -231,9 +232,14 @@ MODULE_DEVICE_TABLE(platform, s3c2410_wdt_ids); /* functions */ -static inline unsigned int s3c2410wdt_max_timeout(struct clk *clock) +static inline unsigned long s3c2410wdt_get_freq(struct s3c2410_wdt *wdt) { - unsigned long freq = clk_get_rate(clock); + return clk_get_rate(wdt->src_clk ? wdt->src_clk : wdt->bus_clk); +} + +static inline unsigned int s3c2410wdt_max_timeout(struct s3c2410_wdt *wdt) +{ + const unsigned long freq = s3c2410wdt_get_freq(wdt); return S3C2410_WTCNT_MAXCNT / (freq / (S3C2410_WTCON_PRESCALE_MAX + 1) / S3C2410_WTCON_MAXDIV); @@ -383,7 +389,7 @@ static int s3c2410wdt_set_heartbeat(struct watchdog_device *wdd, unsigned int timeout) { struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd); - unsigned long freq = clk_get_rate(wdt->clock); + unsigned long freq = s3c2410wdt_get_freq(wdt); unsigned int count; unsigned int divisor = 1; unsigned long wtcon; @@ -632,26 +638,42 @@ static int s3c2410wdt_probe(struct platform_device *pdev) goto err; } - wdt->clock = devm_clk_get(dev, "watchdog"); - if (IS_ERR(wdt->clock)) { - dev_err(dev, "failed to find watchdog clock source\n"); - ret = PTR_ERR(wdt->clock); + wdt->bus_clk = devm_clk_get(dev, "watchdog"); + if (IS_ERR(wdt->bus_clk)) { + dev_err(dev, "failed to find bus clock\n"); + ret = PTR_ERR(wdt->bus_clk); goto err; } - ret = clk_prepare_enable(wdt->clock); + ret = clk_prepare_enable(wdt->bus_clk); if (ret < 0) { - dev_err(dev, "failed to enable clock\n"); + dev_err(dev, "failed to enable bus clock\n"); return ret; } + /* + * "watchdog_src" clock is optional; if it's not present -- just skip it + * and use "watchdog" clock as both bus and source clock. + */ + wdt->src_clk = devm_clk_get(dev, "watchdog_src"); + if (!IS_ERR(wdt->src_clk)) { + ret = clk_prepare_enable(wdt->src_clk); + if (ret < 0) { + dev_err(dev, "failed to enable source clock\n"); + ret = PTR_ERR(wdt->src_clk); + goto err_bus_clk; + } + } else { + wdt->src_clk = NULL; + } + wdt->wdt_device.min_timeout = 1; - wdt->wdt_device.max_timeout = s3c2410wdt_max_timeout(wdt->clock); + wdt->wdt_device.max_timeout = s3c2410wdt_max_timeout(wdt); ret = s3c2410wdt_cpufreq_register(wdt); if (ret < 0) { dev_err(dev, "failed to register cpufreq\n"); - goto err_clk; + goto err_src_clk; } watchdog_set_drvdata(&wdt->wdt_device, wdt); @@ -729,8 +751,11 @@ static int s3c2410wdt_probe(struct platform_device *pdev) err_cpufreq: s3c2410wdt_cpufreq_deregister(wdt); - err_clk: - clk_disable_unprepare(wdt->clock); + err_src_clk: + clk_disable_unprepare(wdt->src_clk); + + err_bus_clk: + clk_disable_unprepare(wdt->bus_clk); err: return ret; @@ -749,7 +774,8 @@ static int s3c2410wdt_remove(struct platform_device *dev) s3c2410wdt_cpufreq_deregister(wdt); - clk_disable_unprepare(wdt->clock); + clk_disable_unprepare(wdt->src_clk); + clk_disable_unprepare(wdt->bus_clk); return 0; }