From patchwork Thu Nov 5 11:38:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Vaittinen, Matti" X-Patchwork-Id: 11883977 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4AF82174A for ; Thu, 5 Nov 2020 11:39:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1DF5120936 for ; Thu, 5 Nov 2020 11:39:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730150AbgKELje (ORCPT ); Thu, 5 Nov 2020 06:39:34 -0500 Received: from mail-lf1-f66.google.com ([209.85.167.66]:38761 "EHLO mail-lf1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726777AbgKELiq (ORCPT ); Thu, 5 Nov 2020 06:38:46 -0500 Received: by mail-lf1-f66.google.com with SMTP id 74so1808435lfo.5; Thu, 05 Nov 2020 03:38:43 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=MmDawDqqG51j1SEyUh74FZXblmEHsPWixia7zM2SpSs=; b=RsHnpJACmaXGbvapesaAGI+tGbqmQKMIIeAVIIq0HvrVokZUH5kEX6HqiazPLJ5T8r uwGCNmtJp6/Dg1cv3B09OTQ9c1uJkw1EP8oSHv+vtPgka/VCDAyRSHMs7DKukMOA3pfh XQx+Fvu1Lt4ZLvC+I2Yizz567DPa+Z659z0j1+0J8oSndzaXtbxAh8Ht0AI4ppz9FNE9 QR2+DOU4Jc+W/rYV5lmjkSOlmXHT7C8E7ya3svZmUm3CCLTy4ullNZhOTRrMhuJrQKFy 8JxdiofSXDzoeYiKq7xNpVOJfeRoMnH2r5lT8ThXEhgeALShCroN5TFboqKgMiyMrgAA PTmQ== X-Gm-Message-State: AOAM5328UcUbn79757RiVAp08lgsHk65/PQM85XOAjYgc+ojcqToxJIv qQyHTUa07BdoHvlAuKYgsns= X-Google-Smtp-Source: ABdhPJx1Ro4rdAnlITy322SBgR5YN4N2QTOQYs5nHPIqMuIHnBmsR70wE43QLnYuOtIFa0KK/jQjcA== X-Received: by 2002:ac2:4d96:: with SMTP id g22mr891886lfe.335.1604576323053; Thu, 05 Nov 2020 03:38:43 -0800 (PST) Received: from localhost.localdomain (62-78-225-252.bb.dnainternet.fi. [62.78.225.252]) by smtp.gmail.com with ESMTPSA id x16sm154127lfn.268.2020.11.05.03.38.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 Nov 2020 03:38:42 -0800 (PST) Date: Thu, 5 Nov 2020 13:38:35 +0200 From: Matti Vaittinen To: matti.vaittinen@fi.rohmeurope.com, mazziesaccount@gmail.com Cc: Lee Jones , Rob Herring , Matti Vaittinen , Wim Van Sebroeck , Guenter Roeck , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-power@fi.rohmeurope.com, linux-watchdog@vger.kernel.org Subject: [PATCH v5 3/4] wdt: Support wdt on ROHM BD9576MUF and BD9573MUF Message-ID: <1a454defaf65ecc22deb0fe42a1384a5f9d5a771.1604574431.git.matti.vaittinen@fi.rohmeurope.com> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org Add Watchdog support for ROHM BD9576MUF and BD9573MUF PMICs which are mainly used to power the R-Car series processors. The watchdog is pinged using a GPIO and enabled using another GPIO. Additionally watchdog time-out can be configured to HW prior starting the watchdog. Watchdog timeout can be configured to detect only delayed ping or in a window mode where also too fast pings are detected. Signed-off-by: Matti Vaittinen Reviewed-by: Guenter Roeck --- drivers/watchdog/Kconfig | 13 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/bd9576_wdt.c | 290 ++++++++++++++++++++++++++++++++++ 3 files changed, 304 insertions(+) create mode 100644 drivers/watchdog/bd9576_wdt.c diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index fd7968635e6d..d5fec1bdf23e 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -172,6 +172,19 @@ config BD70528_WATCHDOG Alternatively say M to compile the driver as a module, which will be called bd70528_wdt. +config BD957XMUF_WATCHDOG + tristate "ROHM BD9576MUF and BD9573MUF PMIC Watchdog" + depends on MFD_ROHM_BD957XMUF + select WATCHDOG_CORE + help + Support for the watchdog in the ROHM BD9576 and BD9573 PMICs. + These PMIC ICs contain watchdog block which can be configured + to toggle reset line if SoC fails to ping watchdog via GPIO. + + Say Y here to include support for the ROHM BD9576 or BD9573 + watchdog. Alternatively say M to compile the driver as a module, + which will be called bd9576_wdt. + config DA9052_WATCHDOG tristate "Dialog DA9052 Watchdog" depends on PMIC_DA9052 || COMPILE_TEST diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 071a2e50be98..54f39883f3ac 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -209,6 +209,7 @@ obj-$(CONFIG_XEN_WDT) += xen_wdt.o # Architecture Independent obj-$(CONFIG_BD70528_WATCHDOG) += bd70528_wdt.o +obj-$(CONFIG_BD957XMUF_WATCHDOG) += bd9576_wdt.o obj-$(CONFIG_DA9052_WATCHDOG) += da9052_wdt.o obj-$(CONFIG_DA9055_WATCHDOG) += da9055_wdt.o obj-$(CONFIG_DA9062_WATCHDOG) += da9062_wdt.o diff --git a/drivers/watchdog/bd9576_wdt.c b/drivers/watchdog/bd9576_wdt.c new file mode 100644 index 000000000000..afef19ce01be --- /dev/null +++ b/drivers/watchdog/bd9576_wdt.c @@ -0,0 +1,290 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2020 ROHM Semiconductors + * + * ROHM BD9576MUF and BD9573MUF Watchdog driver + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +static bool nowayout; +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, + "Watchdog cannot be stopped once started (default=\"false\")"); + +#define HW_MARGIN_MIN 2 +#define HW_MARGIN_MAX 4416 +#define BD957X_WDT_DEFAULT_MARGIN 4416 + +struct bd9576_wdt_priv { + struct gpio_desc *gpiod_ping; + struct gpio_desc *gpiod_en; + struct device *dev; + struct regmap *regmap; + bool always_running; + struct watchdog_device wdd; +}; + +static void bd9576_wdt_disable(struct bd9576_wdt_priv *priv) +{ + gpiod_set_value_cansleep(priv->gpiod_en, 0); +} + +static int bd9576_wdt_ping(struct watchdog_device *wdd) +{ + struct bd9576_wdt_priv *priv = watchdog_get_drvdata(wdd); + + /* Pulse */ + gpiod_set_value_cansleep(priv->gpiod_ping, 1); + gpiod_set_value_cansleep(priv->gpiod_ping, 0); + + return 0; +} + +static int bd9576_wdt_start(struct watchdog_device *wdd) +{ + struct bd9576_wdt_priv *priv = watchdog_get_drvdata(wdd); + + gpiod_set_value_cansleep(priv->gpiod_en, 1); + + return bd9576_wdt_ping(wdd); +} + +static int bd9576_wdt_stop(struct watchdog_device *wdd) +{ + struct bd9576_wdt_priv *priv = watchdog_get_drvdata(wdd); + + if (!priv->always_running) + bd9576_wdt_disable(priv); + else + set_bit(WDOG_HW_RUNNING, &wdd->status); + + return 0; +} + +static const struct watchdog_info bd957x_wdt_ident = { + .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING | + WDIOF_SETTIMEOUT, + .identity = "BD957x Watchdog", +}; + +static const struct watchdog_ops bd957x_wdt_ops = { + .owner = THIS_MODULE, + .start = bd9576_wdt_start, + .stop = bd9576_wdt_stop, + .ping = bd9576_wdt_ping, +}; + +/* Unit is hundreds of uS */ +#define FASTNG_MIN 23 + +static int find_closest_fast(int target, int *sel, int *val) +{ + int i; + int window = FASTNG_MIN; + + for (i = 0; i < 8 && window < target; i++) + window <<= 1; + + *val = window; + *sel = i; + + if (i == 8) + return -EINVAL; + + return 0; + +} + +static int find_closest_slow_by_fast(int fast_val, int target, int *slowsel) +{ + int sel; + static const int multipliers[] = {2, 3, 7, 15}; + + for (sel = 0; sel < ARRAY_SIZE(multipliers) && + multipliers[sel] * fast_val < target; sel++) + ; + + if (sel == ARRAY_SIZE(multipliers)) + return -EINVAL; + + *slowsel = sel; + + return 0; +} + +static int find_closest_slow(int target, int *slow_sel, int *fast_sel) +{ + static const int multipliers[] = {2, 3, 7, 15}; + int i, j; + int val = 0; + int window = FASTNG_MIN; + + for (i = 0; i < 8; i++) { + for (j = 0; j < ARRAY_SIZE(multipliers); j++) { + int slow; + + slow = window * multipliers[j]; + if (slow >= target && (!val || slow < val)) { + val = slow; + *fast_sel = i; + *slow_sel = j; + } + } + window <<= 1; + } + if (!val) + return -EINVAL; + + return 0; +} + +#define BD957X_WDG_TYPE_WINDOW BIT(5) +#define BD957X_WDG_TYPE_SLOW 0 +#define BD957X_WDG_TYPE_MASK BIT(5) +#define BD957X_WDG_NG_RATIO_MASK 0x18 +#define BD957X_WDG_FASTNG_MASK 0x7 + +static int bd957x_set_wdt_mode(struct bd9576_wdt_priv *priv, int hw_margin, + int hw_margin_min) +{ + int ret, fastng, slowng, type, reg, mask; + struct device *dev = priv->dev; + + /* convert to 100uS */ + hw_margin *= 10; + hw_margin_min *= 10; + if (hw_margin_min) { + int min; + + type = BD957X_WDG_TYPE_WINDOW; + dev_dbg(dev, "Setting type WINDOW 0x%x\n", type); + ret = find_closest_fast(hw_margin_min, &fastng, &min); + if (ret) { + dev_err(dev, "bad WDT window for fast timeout\n"); + return ret; + } + + ret = find_closest_slow_by_fast(min, hw_margin, &slowng); + if (ret) { + dev_err(dev, "bad WDT window\n"); + return ret; + } + + } else { + type = BD957X_WDG_TYPE_SLOW; + dev_dbg(dev, "Setting type SLOW 0x%x\n", type); + ret = find_closest_slow(hw_margin, &slowng, &fastng); + if (ret) { + dev_err(dev, "bad WDT window\n"); + return ret; + } + } + + slowng <<= ffs(BD957X_WDG_NG_RATIO_MASK) - 1; + reg = type | slowng | fastng; + mask = BD957X_WDG_TYPE_MASK | BD957X_WDG_NG_RATIO_MASK | + BD957X_WDG_FASTNG_MASK; + ret = regmap_update_bits(priv->regmap, BD957X_REG_WDT_CONF, + mask, reg); + + return ret; +} + +static int bd9576_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->parent->of_node; + struct bd9576_wdt_priv *priv; + u32 hw_margin[2]; + u32 hw_margin_max = BD957X_WDT_DEFAULT_MARGIN, hw_margin_min = 0; + int ret; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + platform_set_drvdata(pdev, priv); + + priv->dev = dev; + priv->regmap = dev_get_regmap(dev->parent, NULL); + if (!priv->regmap) { + dev_err(dev, "No regmap found\n"); + return -ENODEV; + } + + priv->gpiod_en = devm_gpiod_get_from_of_node(dev, dev->parent->of_node, + "rohm,watchdog-enable-gpios", + 0, GPIOD_OUT_LOW, + "watchdog-enable"); + if (IS_ERR(priv->gpiod_en)) + return dev_err_probe(dev, PTR_ERR(priv->gpiod_en), + "getting watchdog-enable GPIO failed\n"); + + priv->gpiod_ping = devm_gpiod_get_from_of_node(dev, dev->parent->of_node, + "rohm,watchdog-ping-gpios", + 0, GPIOD_OUT_LOW, + "watchdog-ping"); + if (IS_ERR(priv->gpiod_ping)) + return dev_err_probe(dev, PTR_ERR(priv->gpiod_ping), + "getting watchdog-ping GPIO failed\n"); + + ret = of_property_read_variable_u32_array(np, "rohm,hw-timeout-ms", + &hw_margin[0], 1, 2); + if (ret < 0 && ret != -EINVAL) + return ret; + + if (ret == 1) + hw_margin_max = hw_margin[0]; + + if (ret == 2) { + hw_margin_max = hw_margin[1]; + hw_margin_min = hw_margin[0]; + } + + ret = bd957x_set_wdt_mode(priv, hw_margin_max, hw_margin_min); + if (ret) + return ret; + + priv->always_running = of_property_read_bool(np, "always-running"); + + watchdog_set_drvdata(&priv->wdd, priv); + + priv->wdd.info = &bd957x_wdt_ident; + priv->wdd.ops = &bd957x_wdt_ops; + priv->wdd.min_hw_heartbeat_ms = hw_margin_min; + priv->wdd.max_hw_heartbeat_ms = hw_margin_max; + priv->wdd.parent = dev; + priv->wdd.timeout = (hw_margin_max / 2) * 1000; + + watchdog_init_timeout(&priv->wdd, 0, dev); + watchdog_set_nowayout(&priv->wdd, nowayout); + + watchdog_stop_on_reboot(&priv->wdd); + + if (priv->always_running) + bd9576_wdt_start(&priv->wdd); + + return devm_watchdog_register_device(dev, &priv->wdd); +} + +static struct platform_driver bd9576_wdt_driver = { + .driver = { + .name = "bd9576-wdt", + }, + .probe = bd9576_wdt_probe, +}; + +module_platform_driver(bd9576_wdt_driver); + +MODULE_AUTHOR("Matti Vaittinen "); +MODULE_DESCRIPTION("ROHM BD9576/BD9573 Watchdog driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:bd9576-wdt");