From patchwork Fri Sep 18 22:13:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nobuhiro Iwamatsu X-Patchwork-Id: 11786495 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 2F1C314B7 for ; Fri, 18 Sep 2020 22:14:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B5792311C for ; Fri, 18 Sep 2020 22:14:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726280AbgIRWOR (ORCPT ); Fri, 18 Sep 2020 18:14:17 -0400 Received: from mo-csw1116.securemx.jp ([210.130.202.158]:44580 "EHLO mo-csw.securemx.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726245AbgIRWOR (ORCPT ); Fri, 18 Sep 2020 18:14:17 -0400 Received: by mo-csw.securemx.jp (mx-mo-csw1116) id 08IMDgGp016519; Sat, 19 Sep 2020 07:13:42 +0900 X-Iguazu-Qid: 2wHHUwt3Purs8MQLfl X-Iguazu-QSIG: v=2; s=0; t=1600467222; q=2wHHUwt3Purs8MQLfl; m=5iTT7FyYogXR169A3Sc88jjH9/aQrSzjeGbf/K8D5X0= Received: from imx12.toshiba.co.jp (imx12.toshiba.co.jp [61.202.160.132]) by relay.securemx.jp (mx-mr1112) id 08IMDeXs031262; Sat, 19 Sep 2020 07:13:41 +0900 Received: from enc02.toshiba.co.jp ([61.202.160.51]) by imx12.toshiba.co.jp with ESMTP id 08IMDejf019254; Sat, 19 Sep 2020 07:13:40 +0900 (JST) Received: from hop101.toshiba.co.jp ([133.199.85.107]) by enc02.toshiba.co.jp with ESMTP id 08IMDe8Q011729; Sat, 19 Sep 2020 07:13:40 +0900 From: Nobuhiro Iwamatsu To: Rob Herring , Wim Van Sebroeck , Guenter Roeck Cc: punit1.agrawal@toshiba.co.jp, yuji2.ishikawa@toshiba.co.jp, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-watchdog@vger.kernel.org, Nobuhiro Iwamatsu Subject: [PATCH v2 2/2] watchdog: Add Toshiba Visconti watchdog driver Date: Sat, 19 Sep 2020 07:13:37 +0900 X-TSB-HOP: ON Message-Id: <20200918221337.257157-3-nobuhiro1.iwamatsu@toshiba.co.jp> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200918221337.257157-1-nobuhiro1.iwamatsu@toshiba.co.jp> References: <20200918221337.257157-1-nobuhiro1.iwamatsu@toshiba.co.jp> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org Add the watchdog driver for Toshiba Visconti series. Signed-off-by: Nobuhiro Iwamatsu --- drivers/watchdog/Kconfig | 8 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/visconti_wdt.c | 195 ++++++++++++++++++++++++++++++++ 3 files changed, 204 insertions(+) create mode 100644 drivers/watchdog/visconti_wdt.c diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index ab7aad5a1e69..0cb078ce5e9d 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1004,6 +1004,14 @@ config PM8916_WATCHDOG Say Y here to include support watchdog timer embedded into the pm8916 module. +config VISCONTI_WATCHDOG + tristate "Toshiba Visconti series watchdog support" + depends on ARCH_VISCONTI || COMPILE_TEST + select WATCHDOG_CORE + help + Say Y here to include support for the watchdog timer in Toshiba + Visconti SoCs. + # X86 (i386 + ia64 + x86_64) Architecture config ACQUIRE_WDT diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 97bed1d3d97c..a7747e76fd29 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -95,6 +95,7 @@ obj-$(CONFIG_RTD119X_WATCHDOG) += rtd119x_wdt.o obj-$(CONFIG_SPRD_WATCHDOG) += sprd_wdt.o obj-$(CONFIG_PM8916_WATCHDOG) += pm8916_wdt.o obj-$(CONFIG_ARM_SMC_WATCHDOG) += arm_smc_wdt.o +obj-$(CONFIG_VISCONTI_WATCHDOG) += visconti_wdt.o # X86 (i386 + ia64 + x86_64) Architecture obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o diff --git a/drivers/watchdog/visconti_wdt.c b/drivers/watchdog/visconti_wdt.c new file mode 100644 index 000000000000..cb8a88e4737e --- /dev/null +++ b/drivers/watchdog/visconti_wdt.c @@ -0,0 +1,195 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2020 TOSHIBA CORPORATION + * Copyright (c) 2020 Toshiba Electronic Devices & Storage Corporation + * Copyright (c) 2020 Nobuhiro Iwamatsu + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define WDT_CNT 0x00 +#define WDT_MIN 0x04 +#define WDT_MAX 0x08 +#define WDT_CTL 0x0c +#define WDT_CMD 0x10 +#define WDT_CMD_CLEAR 0x4352 +#define WDT_CMD_START_STOP 0x5354 +#define WDT_DIV 0x30 + +#define VISCONTI_WDT_FREQ 2000000 /* 2MHz */ +#define WDT_DEFAULT_TIMEOUT 10U /* in seconds */ + +static bool nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, bool, 0); +MODULE_PARM_DESC( + nowayout, + "Watchdog cannot be stopped once started (default=" __MODULE_STRING( + WATCHDOG_NOWAYOUT) ")"); + +struct visconti_wdt_priv { + struct watchdog_device wdev; + void __iomem *base; + u32 div; +}; + +static int visconti_wdt_start(struct watchdog_device *wdev) +{ + struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdev); + u32 timeout = wdev->timeout * VISCONTI_WDT_FREQ; + + writel(priv->div, priv->base + WDT_DIV); + writel(0, priv->base + WDT_MIN); + writel(timeout, priv->base + WDT_MAX); + writel(0, priv->base + WDT_CTL); + writel(WDT_CMD_START_STOP, priv->base + WDT_CMD); + + return 0; +} + +static int visconti_wdt_stop(struct watchdog_device *wdev) +{ + struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdev); + + writel(1, priv->base + WDT_CTL); + writel(WDT_CMD_START_STOP, priv->base + WDT_CMD); + + return 0; +} + +static int visconti_wdt_ping(struct watchdog_device *wdd) +{ + struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdd); + + writel(WDT_CMD_CLEAR, priv->base + WDT_CMD); + + return 0; +} + +static unsigned int visconti_wdt_get_timeleft(struct watchdog_device *wdev) +{ + struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdev); + u32 timeout = wdev->timeout * VISCONTI_WDT_FREQ; + u32 cnt = readl(priv->base + WDT_CNT); + + if (timeout > cnt) + timeout -= cnt; + else + return 0; + + return timeout / VISCONTI_WDT_FREQ; +} + +static int visconti_wdt_set_timeout(struct watchdog_device *wdev, + unsigned int timeout) +{ + u32 val; + struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdev); + + wdev->timeout = timeout; + val = wdev->timeout * VISCONTI_WDT_FREQ; + + /* Clear counter before setting timeout because WDT expires */ + writel(WDT_CMD_CLEAR, priv->base + WDT_CMD); + writel(val, priv->base + WDT_MAX); + + return 0; +} + +static const struct watchdog_info visconti_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, + .identity = "Visconti Watchdog", +}; + +static const struct watchdog_ops visconti_wdt_ops = { + .owner = THIS_MODULE, + .start = visconti_wdt_start, + .stop = visconti_wdt_stop, + .ping = visconti_wdt_ping, + .get_timeleft = visconti_wdt_get_timeleft, + .set_timeout = visconti_wdt_set_timeout, +}; + +static int visconti_wdt_probe(struct platform_device *pdev) +{ + struct watchdog_device *wdev; + struct visconti_wdt_priv *priv; + struct device *dev = &pdev->dev; + struct clk *clk; + int ret; + unsigned long clk_freq; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(priv->base)) + return PTR_ERR(priv->base); + + clk = devm_clk_get(dev, NULL); + if (IS_ERR(clk)) + return dev_err_probe(dev, PTR_ERR(clk), + "Could not get clock\n"); + + ret = clk_prepare_enable(clk); + if (ret) { + dev_err(dev, "Could not enable clock\n"); + return ret; + } + + clk_freq = clk_get_rate(clk); + if (!clk_freq) { + clk_disable_unprepare(clk); + dev_err(dev, "Could not get clock rate\n"); + return -EINVAL; + } + + priv->div = clk_freq / VISCONTI_WDT_FREQ; + + /* Initialize struct watchdog_device. */ + wdev = &priv->wdev; + wdev->info = &visconti_wdt_info; + wdev->ops = &visconti_wdt_ops; + wdev->parent = dev; + wdev->min_timeout = 1; + wdev->max_timeout = 0xffffffff / VISCONTI_WDT_FREQ; + wdev->timeout = min(wdev->max_timeout, WDT_DEFAULT_TIMEOUT); + + watchdog_set_drvdata(wdev, priv); + watchdog_set_nowayout(wdev, nowayout); + watchdog_stop_on_unregister(wdev); + + /* This overrides the default timeout only if DT configuration was found */ + ret = watchdog_init_timeout(wdev, 0, dev); + if (ret) + dev_warn(dev, "Specified timeout value invalid, using default\n"); + + return devm_watchdog_register_device(dev, wdev); +} + +static const struct of_device_id visconti_wdt_of_match[] = { + { .compatible = "toshiba,visconti-wdt", }, + {} +}; +MODULE_DEVICE_TABLE(of, visconti_wdt_of_match); + +static struct platform_driver visconti_wdt_driver = { + .driver = { + .name = "visconti_wdt", + .of_match_table = visconti_wdt_of_match, + }, + .probe = visconti_wdt_probe, +}; +module_platform_driver(visconti_wdt_driver); + +MODULE_DESCRIPTION("TOSHIBA Visconti Watchdog Driver"); +MODULE_AUTHOR("TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION"); +MODULE_AUTHOR("Nobuhiro Iwamatsu