From patchwork Thu Nov 11 22:58:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luca Ceresoli X-Patchwork-Id: 517837 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 CC5D9C433FE for ; Thu, 11 Nov 2021 23:00:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B894561208 for ; Thu, 11 Nov 2021 23:00:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234473AbhKKXDD (ORCPT ); Thu, 11 Nov 2021 18:03:03 -0500 Received: from hostingweb31-40.netsons.net ([89.40.174.40]:43519 "EHLO hostingweb31-40.netsons.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234453AbhKKXDC (ORCPT ); Thu, 11 Nov 2021 18:03:02 -0500 Received: from [77.244.183.192] (port=63166 helo=melee.fritz.box) by hostingweb31.netsons.net with esmtpa (Exim 4.94.2) (envelope-from ) id 1mlJ3D-0007N5-B6; Fri, 12 Nov 2021 00:00:11 +0100 From: Luca Ceresoli To: linux-kernel@vger.kernel.org Cc: Luca Ceresoli , Lee Jones , Rob Herring , Chanwoo Choi , Krzysztof Kozlowski , Bartlomiej Zolnierkiewicz , Alessandro Zummo , Alexandre Belloni , Wim Van Sebroeck , Guenter Roeck , devicetree@vger.kernel.org, linux-rtc@vger.kernel.org, linux-watchdog@vger.kernel.org, Chiwoong Byun , Laxman Dewangan , Randy Dunlap Subject: [PATCH v3 7/8] watchdog: max77714: add driver for the watchdog in the MAX77714 PMIC Date: Thu, 11 Nov 2021 23:58:51 +0100 Message-Id: <20211111225852.3128201-8-luca@lucaceresoli.net> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211111225852.3128201-1-luca@lucaceresoli.net> References: <20211111225852.3128201-1-luca@lucaceresoli.net> MIME-Version: 1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - hostingweb31.netsons.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - lucaceresoli.net X-Get-Message-Sender-Via: hostingweb31.netsons.net: authenticated_id: luca+lucaceresoli.net/only user confirmed/virtual account not confirmed X-Authenticated-Sender: hostingweb31.netsons.net: luca@lucaceresoli.net X-Source: X-Source-Args: X-Source-Dir: Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org Add a simple driver to support the watchdog embedded in the Maxim MAX77714 PMIC. Signed-off-by: Luca Ceresoli --- Changes in v3: none Changes in v2: - fix Kconfig help indentation (Randy Dunlap) - make max77714_margin_value static const (Guenter Roeck) - fix platform module instantiation --- MAINTAINERS | 1 + drivers/watchdog/Kconfig | 9 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/max77714_wdt.c | 179 ++++++++++++++++++++++++++++++++ 4 files changed, 190 insertions(+) create mode 100644 drivers/watchdog/max77714_wdt.c diff --git a/MAINTAINERS b/MAINTAINERS index 1a37b9422c5f..d182231b4bbf 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11573,6 +11573,7 @@ M: Luca Ceresoli S: Maintained F: Documentation/devicetree/bindings/mfd/maxim,max77714.yaml F: drivers/mfd/max77714.c +F: drivers/watchdog/max77714_wdt.c F: include/linux/mfd/max77714.h MAXIM MAX77802 PMIC REGULATOR DEVICE DRIVER diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index a6d97f30325a..f5100b731927 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -685,6 +685,15 @@ config MAX77620_WATCHDOG MAX77620 chips. To compile this driver as a module, choose M here: the module will be called max77620_wdt. +config MAX77714_WATCHDOG + tristate "Maxim MAX77714 Watchdog Timer" + depends on MFD_MAX77714 || COMPILE_TEST + help + This is the driver for watchdog timer in the MAX77714 PMIC. + Say 'Y' here to enable the watchdog timer support for MAX77714 + chips. To compile this driver as a module, choose M here: the + module will be called max77714_wdt. + config IMX2_WDT tristate "IMX2+ Watchdog" depends on ARCH_MXC || ARCH_LAYERSCAPE || COMPILE_TEST diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 2ee97064145b..575be33c52b8 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -214,6 +214,7 @@ obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o obj-$(CONFIG_MAX77620_WATCHDOG) += max77620_wdt.o +obj-$(CONFIG_MAX77714_WATCHDOG) += max77714_wdt.o obj-$(CONFIG_ZIIRAVE_WATCHDOG) += ziirave_wdt.o obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o diff --git a/drivers/watchdog/max77714_wdt.c b/drivers/watchdog/max77714_wdt.c new file mode 100644 index 000000000000..cce6c13d76eb --- /dev/null +++ b/drivers/watchdog/max77714_wdt.c @@ -0,0 +1,179 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Maxim MAX77714 Watchdog Driver + * + * Copyright (C) 2021 Luca Ceresoli + * Author: Luca Ceresoli + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +struct max77714_wdt { + struct device *dev; + struct regmap *rmap; + struct watchdog_device wd_dev; +}; + +/* Timeout in seconds, indexed by TWD bits of CNFG_GLBL2 register */ +static const unsigned int max77714_margin_value[] = { 2, 16, 64, 128 }; + +static int max77714_wdt_start(struct watchdog_device *wd_dev) +{ + struct max77714_wdt *wdt = watchdog_get_drvdata(wd_dev); + + return regmap_update_bits(wdt->rmap, MAX77714_CNFG_GLBL2, + MAX77714_WDTEN, MAX77714_WDTEN); +} + +static int max77714_wdt_stop(struct watchdog_device *wd_dev) +{ + struct max77714_wdt *wdt = watchdog_get_drvdata(wd_dev); + + return regmap_update_bits(wdt->rmap, MAX77714_CNFG_GLBL2, + MAX77714_WDTEN, 0); +} + +static int max77714_wdt_ping(struct watchdog_device *wd_dev) +{ + struct max77714_wdt *wdt = watchdog_get_drvdata(wd_dev); + + return regmap_update_bits(wdt->rmap, MAX77714_CNFG_GLBL3, + MAX77714_WDTC, 1); +} + +static int max77714_wdt_set_timeout(struct watchdog_device *wd_dev, + unsigned int timeout) +{ + struct max77714_wdt *wdt = watchdog_get_drvdata(wd_dev); + unsigned int new_timeout, new_twd; + int err; + + for (new_twd = 0; new_twd < ARRAY_SIZE(max77714_margin_value) - 1; new_twd++) + if (timeout <= max77714_margin_value[new_twd]) + break; + + /* new_wdt is not out of bounds here due to the "- 1" in the for loop */ + new_timeout = max77714_margin_value[new_twd]; + + /* + * "If the value of TWD needs to be changed, clear the system + * watchdog timer first [...], then change the value of TWD." + * (MAX77714 datasheet) + */ + err = regmap_update_bits(wdt->rmap, MAX77714_CNFG_GLBL3, + MAX77714_WDTC, 1); + if (err) + return err; + + err = regmap_update_bits(wdt->rmap, MAX77714_CNFG_GLBL2, + MAX77714_TWD_MASK, new_twd); + if (err) + return err; + + wd_dev->timeout = new_timeout; + + dev_dbg(wdt->dev, "New timeout = %u s (WDT = 0x%x)", new_timeout, new_twd); + + return 0; +} + +static const struct watchdog_info max77714_wdt_info = { + .identity = "max77714-watchdog", + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, +}; + +static const struct watchdog_ops max77714_wdt_ops = { + .start = max77714_wdt_start, + .stop = max77714_wdt_stop, + .ping = max77714_wdt_ping, + .set_timeout = max77714_wdt_set_timeout, +}; + +static int max77714_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct max77714_wdt *wdt; + struct watchdog_device *wd_dev; + unsigned int regval; + int err; + + wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + + wdt->dev = dev; + + wd_dev = &wdt->wd_dev; + wd_dev->info = &max77714_wdt_info; + wd_dev->ops = &max77714_wdt_ops; + wd_dev->min_timeout = 2; + wd_dev->max_timeout = 128; + + platform_set_drvdata(pdev, wdt); + watchdog_set_drvdata(wd_dev, wdt); + + wdt->rmap = dev_get_regmap(dev->parent, NULL); + if (!wdt->rmap) + return dev_err_probe(wdt->dev, -ENODEV, "Failed to get parent regmap\n"); + + /* WD_RST_WK: if 1 wdog restarts; if 0 wdog shuts down */ + err = regmap_update_bits(wdt->rmap, MAX77714_CNFG2_ONOFF, + MAX77714_WD_RST_WK, MAX77714_WD_RST_WK); + if (err) + return dev_err_probe(wdt->dev, err, "Error updating CNFG2_ONOFF\n"); + + err = regmap_read(wdt->rmap, MAX77714_CNFG_GLBL2, ®val); + if (err) + return dev_err_probe(wdt->dev, err, "Error reading CNFG_GLBL2\n"); + + /* enable watchdog | enable auto-clear in sleep state */ + regval |= (MAX77714_WDTEN | MAX77714_WDTSLPC); + + err = regmap_write(wdt->rmap, MAX77714_CNFG_GLBL2, regval); + if (err) + return dev_err_probe(wdt->dev, err, "Error writing CNFG_GLBL2\n"); + + wd_dev->timeout = max77714_margin_value[regval & MAX77714_TWD_MASK]; + + dev_dbg(wdt->dev, "Timeout = %u s (WDT = 0x%x)", + wd_dev->timeout, regval & MAX77714_TWD_MASK); + + set_bit(WDOG_HW_RUNNING, &wd_dev->status); + + watchdog_stop_on_unregister(wd_dev); + + err = devm_watchdog_register_device(dev, wd_dev); + if (err) + return dev_err_probe(dev, err, "Cannot register watchdog device\n"); + + dev_info(dev, "registered as /dev/watchdog%d\n", wd_dev->id); + + return 0; +} + +static const struct platform_device_id max77714_wdt_platform_id[] = { + { .name = "max77714-watchdog", }, + { }, +}; +MODULE_DEVICE_TABLE(platform, max77714_wdt_platform_id); + +static struct platform_driver max77714_wdt_driver = { + .driver = { + .name = "max77714-watchdog", + }, + .probe = max77714_wdt_probe, + .id_table = max77714_wdt_platform_id, +}; + +module_platform_driver(max77714_wdt_driver); + +MODULE_DESCRIPTION("MAX77714 watchdog timer driver"); +MODULE_AUTHOR("Luca Ceresoli "); +MODULE_LICENSE("GPL v2");