From patchwork Mon Aug 3 09:35:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Walle X-Patchwork-Id: 11697769 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 AC87E14DD for ; Mon, 3 Aug 2020 09:43:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8EC592075A for ; Mon, 3 Aug 2020 09:43:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=walle.cc header.i=@walle.cc header.b="CLBIgRK+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726963AbgHCJnZ (ORCPT ); Mon, 3 Aug 2020 05:43:25 -0400 Received: from ssl.serverraum.org ([176.9.125.105]:44577 "EHLO ssl.serverraum.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726130AbgHCJmo (ORCPT ); Mon, 3 Aug 2020 05:42:44 -0400 Received: from mwalle01.sab.local. (unknown [213.135.10.150]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ssl.serverraum.org (Postfix) with ESMTPSA id E01A923E45; Mon, 3 Aug 2020 11:42:38 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2016061301; t=1596447759; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Nll2nIYoKjy89WeTWZ/ueYdcUnkm9S21+VXP3st7jU4=; b=CLBIgRK+aAV5V8SNAeYuVrK+n5b1Keu5hbTvy7lwhKbIC5jmaZ8tnlByECRvJavnvxAXq4 HQSwxKtMXnxJNN7pWMut1RS12uvwpte8JSUptS/Cpuh6MRJrAa4i6VBcLHB2qthjcqXWIr VU65oxGZKnbLPAyCrHiHadTHA77ke3k= From: Michael Walle To: linux-gpio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-pwm@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Linus Walleij , Bartosz Golaszewski , Rob Herring , Jean Delvare , Guenter Roeck , Lee Jones , Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , Wim Van Sebroeck , Shawn Guo , Li Yang , Thomas Gleixner , Jason Cooper , Marc Zyngier , Mark Brown , Greg Kroah-Hartman , Andy Shevchenko , Catalin Marinas , Will Deacon , Pavel Machek , Michael Walle Subject: [PATCH v7 05/13] watchdog: add support for sl28cpld watchdog Date: Mon, 3 Aug 2020 11:35:51 +0200 Message-Id: <20200803093559.12289-6-michael@walle.cc> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200803093559.12289-1-michael@walle.cc> References: <20200803093559.12289-1-michael@walle.cc> MIME-Version: 1.0 X-Spam: Yes Sender: linux-watchdog-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org Add support for the watchdog of the sl28cpld board management controller. This is part of a multi-function device driver. Signed-off-by: Michael Walle Acked-by: Guenter Roeck --- Changes since v6: - none Changes since v5: - none Changes since v4: - update copyright year - remove #include , suggested by Andy. - slightly reworked the error code handling (only style), suggested by Andy. - Don't use "if (ret < 0)", but only "if (ret)", suggested by Andy. - remove comma in terminator line of the compatible strings list - don't use KBUID_MODNAME - remove the platform device table Changes since v3: - see cover letter drivers/watchdog/Kconfig | 11 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/sl28cpld_wdt.c | 229 ++++++++++++++++++++++++++++++++ 3 files changed, 241 insertions(+) create mode 100644 drivers/watchdog/sl28cpld_wdt.c diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 4f4687c46d38..c4115ea0d3f8 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -340,6 +340,17 @@ config MLX_WDT To compile this driver as a module, choose M here: the module will be called mlx-wdt. +config SL28CPLD_WATCHDOG + tristate "Kontron sl28cpld Watchdog" + select MFD_SIMPLE_MFD_I2C + select WATCHDOG_CORE + help + Say Y here to include support for the watchdog timer + on the Kontron sl28 CPLD. + + To compile this driver as a module, choose M here: the + module will be called sl28cpld_wdt. + # ALPHA Architecture # ARM Architecture diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 97bed1d3d97c..aa6e41126901 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -225,3 +225,4 @@ obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o obj-$(CONFIG_MENZ069_WATCHDOG) += menz69_wdt.o obj-$(CONFIG_RAVE_SP_WATCHDOG) += rave-sp-wdt.o obj-$(CONFIG_STPMIC1_WATCHDOG) += stpmic1_wdt.o +obj-$(CONFIG_SL28CPLD_WATCHDOG) += sl28cpld_wdt.o diff --git a/drivers/watchdog/sl28cpld_wdt.c b/drivers/watchdog/sl28cpld_wdt.c new file mode 100644 index 000000000000..a45047d8d9ab --- /dev/null +++ b/drivers/watchdog/sl28cpld_wdt.c @@ -0,0 +1,229 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * sl28cpld watchdog driver + * + * Copyright 2020 Kontron Europe GmbH + */ + +#include +#include +#include +#include +#include +#include +#include + +/* + * Watchdog timer block registers. + */ +#define WDT_CTRL 0x00 +#define WDT_CTRL_EN BIT(0) +#define WDT_CTRL_LOCK BIT(2) +#define WDT_CTRL_ASSERT_SYS_RESET BIT(6) +#define WDT_CTRL_ASSERT_WDT_TIMEOUT BIT(7) +#define WDT_TIMEOUT 0x01 +#define WDT_KICK 0x02 +#define WDT_KICK_VALUE 0x6b +#define WDT_COUNT 0x03 + +#define WDT_DEFAULT_TIMEOUT 10 + +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) ")"); + +static int timeout; +module_param(timeout, int, 0); +MODULE_PARM_DESC(timeout, "Initial watchdog timeout in seconds"); + +struct sl28cpld_wdt { + struct watchdog_device wdd; + struct regmap *regmap; + u32 offset; + bool assert_wdt_timeout; +}; + +static int sl28cpld_wdt_ping(struct watchdog_device *wdd) +{ + struct sl28cpld_wdt *wdt = watchdog_get_drvdata(wdd); + + return regmap_write(wdt->regmap, wdt->offset + WDT_KICK, + WDT_KICK_VALUE); +} + +static int sl28cpld_wdt_start(struct watchdog_device *wdd) +{ + struct sl28cpld_wdt *wdt = watchdog_get_drvdata(wdd); + unsigned int val; + + val = WDT_CTRL_EN | WDT_CTRL_ASSERT_SYS_RESET; + if (wdt->assert_wdt_timeout) + val |= WDT_CTRL_ASSERT_WDT_TIMEOUT; + if (nowayout) + val |= WDT_CTRL_LOCK; + + return regmap_update_bits(wdt->regmap, wdt->offset + WDT_CTRL, + val, val); +} + +static int sl28cpld_wdt_stop(struct watchdog_device *wdd) +{ + struct sl28cpld_wdt *wdt = watchdog_get_drvdata(wdd); + + return regmap_update_bits(wdt->regmap, wdt->offset + WDT_CTRL, + WDT_CTRL_EN, 0); +} + +static unsigned int sl28cpld_wdt_get_timeleft(struct watchdog_device *wdd) +{ + struct sl28cpld_wdt *wdt = watchdog_get_drvdata(wdd); + unsigned int val; + int ret; + + ret = regmap_read(wdt->regmap, wdt->offset + WDT_COUNT, &val); + if (ret) + return 0; + + return val; +} + +static int sl28cpld_wdt_set_timeout(struct watchdog_device *wdd, + unsigned int timeout) +{ + struct sl28cpld_wdt *wdt = watchdog_get_drvdata(wdd); + int ret; + + ret = regmap_write(wdt->regmap, wdt->offset + WDT_TIMEOUT, timeout); + if (ret) + return ret; + + wdd->timeout = timeout; + + return 0; +} + +static const struct watchdog_info sl28cpld_wdt_info = { + .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, + .identity = "sl28cpld watchdog", +}; + +static struct watchdog_ops sl28cpld_wdt_ops = { + .owner = THIS_MODULE, + .start = sl28cpld_wdt_start, + .stop = sl28cpld_wdt_stop, + .ping = sl28cpld_wdt_ping, + .set_timeout = sl28cpld_wdt_set_timeout, + .get_timeleft = sl28cpld_wdt_get_timeleft, +}; + +static int sl28cpld_wdt_probe(struct platform_device *pdev) +{ + struct watchdog_device *wdd; + struct sl28cpld_wdt *wdt; + unsigned int status; + unsigned int val; + int ret; + + if (!pdev->dev.parent) + return -ENODEV; + + wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + + wdt->regmap = dev_get_regmap(pdev->dev.parent, NULL); + if (!wdt->regmap) + return -ENODEV; + + ret = device_property_read_u32(&pdev->dev, "reg", &wdt->offset); + if (ret) + return -EINVAL; + + wdt->assert_wdt_timeout = device_property_read_bool(&pdev->dev, + "kontron,assert-wdt-timeout-pin"); + + /* initialize struct watchdog_device */ + wdd = &wdt->wdd; + wdd->parent = &pdev->dev; + wdd->info = &sl28cpld_wdt_info; + wdd->ops = &sl28cpld_wdt_ops; + wdd->min_timeout = 1; + wdd->max_timeout = 255; + + watchdog_set_drvdata(wdd, wdt); + watchdog_stop_on_reboot(wdd); + + /* + * Read the status early, in case of an error, we haven't modified the + * hardware. + */ + ret = regmap_read(wdt->regmap, wdt->offset + WDT_CTRL, &status); + if (ret) + return ret; + + /* + * Initial timeout value, may be overwritten by device tree or module + * parmeter in watchdog_init_timeout(). + * + * Reading a zero here means that either the hardware has a default + * value of zero (which is very unlikely and definitely a hardware + * bug) or the bootloader set it to zero. In any case, we handle + * this case gracefully and set out own timeout. + */ + ret = regmap_read(wdt->regmap, wdt->offset + WDT_TIMEOUT, &val); + if (ret) + return ret; + + if (val) + wdd->timeout = val; + else + wdd->timeout = WDT_DEFAULT_TIMEOUT; + + watchdog_init_timeout(wdd, timeout, &pdev->dev); + sl28cpld_wdt_set_timeout(wdd, wdd->timeout); + + /* if the watchdog is locked, we set nowayout */ + if (status & WDT_CTRL_LOCK) + nowayout = true; + watchdog_set_nowayout(wdd, nowayout); + + /* + * If watchdog is already running, keep it enabled, but make + * sure its mode is set correctly. + */ + if (status & WDT_CTRL_EN) { + sl28cpld_wdt_start(wdd); + set_bit(WDOG_HW_RUNNING, &wdd->status); + } + + ret = devm_watchdog_register_device(&pdev->dev, wdd); + if (ret < 0) { + dev_err(&pdev->dev, "failed to register watchdog device\n"); + return ret; + } + + dev_info(&pdev->dev, "initial timeout %d sec%s\n", + wdd->timeout, nowayout ? ", nowayout" : ""); + + return 0; +} + +static const struct of_device_id sl28cpld_wdt_of_match[] = { + { .compatible = "kontron,sl28cpld-wdt" }, + {} +}; +MODULE_DEVICE_TABLE(of, sl28cpld_wdt_of_match); + +static struct platform_driver sl28cpld_wdt_driver = { + .probe = sl28cpld_wdt_probe, + .driver = { + .name = "sl28cpld-wdt", + .of_match_table = sl28cpld_wdt_of_match, + }, +}; +module_platform_driver(sl28cpld_wdt_driver); + +MODULE_DESCRIPTION("sl28cpld Watchdog Driver"); +MODULE_AUTHOR("Michael Walle "); +MODULE_LICENSE("GPL");