Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933044Ab3EOSrf (ORCPT ); Wed, 15 May 2013 14:47:35 -0400 Received: from mail-bk0-f47.google.com ([209.85.214.47]:51786 "EHLO mail-bk0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759904Ab3EOSre (ORCPT ); Wed, 15 May 2013 14:47:34 -0400 From: johannes.thumshirn@men.de To: wim@iguana.be Cc: linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org, Johannes Thumshirn Subject: [PATCH v3] watchdog: New watchdog driver for MEN A21 watchdogs Date: Wed, 15 May 2013 20:50:10 +0200 Message-Id: <1368643810-2789-1-git-send-email-johannes.thumshirn@men.de> X-Mailer: git-send-email 1.8.2.3 In-Reply-To: <1368560034.24692.4.camel@joe-AO722> References: <1368560034.24692.4.camel@joe-AO722> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 10145 Lines: 399 From: Johannes Thumshirn This patch adds the driver for the watchdog devices found on MEN Mikro Elektronik A21 VMEbus CPU Carrier Boards. It has DT-support and uses the watchdog framework. Revision 2: * Removed unneeded open flag in struct a21_wdt_drv * Corrected 3bit reason code from gpio * Additional sysfs files are now part of watchdog sysfs * Changed OFF/ON delay in ping from 400ms to 10ns * Reworked timeout setting * Removed a21_wdt_ioctl(...) Revision 3: * Changed pr_{err,info} to dev_{err,info} * Removed out of memory error print * Transition from "fast" to "slow" mode not allowed by chip Signed-off-by: Johannes Thumshirn --- MAINTAINERS | 6 + drivers/watchdog/Kconfig | 8 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/mena21_wdt.c | 309 +++++++++++++++++++++++++++++++++++++++++ 4 files changed, 324 insertions(+) create mode 100644 drivers/watchdog/mena21_wdt.c diff --git a/MAINTAINERS b/MAINTAINERS index 3d7782b..3e5b3f1 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5291,6 +5291,12 @@ F: drivers/mtd/ F: include/linux/mtd/ F: include/uapi/mtd/ +MEN A21 WATCHDOG DRIVER +M: Johannes Thumshirn +L: linux-watchdog@vger.kernel.org +S: Supported +F: drivers/watchdog/mena21_wdt.c + METAG ARCHITECTURE M: James Hogan S: Supported diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index e89fc31..192b84d 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1172,6 +1172,14 @@ config BOOKE_WDT_DEFAULT_TIMEOUT The value can be overridden by the wdt_period command-line parameter. +config MEN_A21_WDT + tristate "MEN A21 VME CPU Carrier Board Watchdog Timer" + select WATCHDOG_CORE + help + Watchdog driver for MEN A21 VMEbus CPU Carrier Boards. + + If unsure select N here. + # PPC64 Architecture config WATCHDOG_RTAS diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index a300b94..bffdcb1 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -143,6 +143,7 @@ obj-$(CONFIG_8xxx_WDT) += mpc8xxx_wdt.o obj-$(CONFIG_MV64X60_WDT) += mv64x60_wdt.o obj-$(CONFIG_PIKA_WDT) += pika_wdt.o obj-$(CONFIG_BOOKE_WDT) += booke_wdt.o +obj-$(CONFIG_MEN_A21_WDT) += mena21_wdt.o # PPC64 Architecture obj-$(CONFIG_WATCHDOG_RTAS) += wdrtas.o diff --git a/drivers/watchdog/mena21_wdt.c b/drivers/watchdog/mena21_wdt.c new file mode 100644 index 0000000..389bd59 --- /dev/null +++ b/drivers/watchdog/mena21_wdt.c @@ -0,0 +1,309 @@ +/* + * Watchdog driver for the A21 VME CPU Boards + * + * Copyright (C) 2013 MEN Mikro Elektronik Nuernberg GmbH + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static char *reset_causes[] = { + "Power On Reset", + "CPU Reset Request", + "Push Button", + "FPGA Reset Request", + "Watchdog", + "Local Power Bad", + "Invalid", + "BDI", +}; + +#define GPIO_WD_ENAB 169 +#define GPIO_WD_FAST 170 +#define GPIO_WD_TRIG 171 + +#define GPIO_RST_CAUSE_BASE 166 + +struct a21_wdt_drv { + struct watchdog_device wdt; + struct mutex lock; +}; + +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 ssize_t rebootcause_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + unsigned int reset = 0; + int i; + + for (i = 0; i < 3; i++) + reset |= gpio_get_value(GPIO_RST_CAUSE_BASE + i) + ? (1 << i) : 0; + + if (reset >= 8) + return -EIO; + + return sprintf(buf, "%s\n", reset_causes[reset]); +} +static DEVICE_ATTR(rebootcause, S_IRUGO, rebootcause_show, NULL); + +static ssize_t active_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return sprintf(buf, "%d\n", !!gpio_get_value(GPIO_WD_ENAB)); +} +static DEVICE_ATTR(active, S_IRUGO, active_show, NULL); + +static ssize_t allow_disable_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + return sprintf(buf, "%d\n", !nowayout); +} +static DEVICE_ATTR(allow_disable, S_IRUGO, allow_disable_show, NULL); + +static ssize_t fastmode_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return sprintf(buf, "%d\n", !!gpio_get_value(GPIO_WD_FAST)); +} +static DEVICE_ATTR(fastmode, S_IRUGO, fastmode_show, NULL); + +static int a21_wdt_create_files(struct watchdog_device *wdev) +{ + int ret; + + ret = device_create_file(wdev->dev, &dev_attr_rebootcause); + if (ret) + return ret; + ret = device_create_file(wdev->dev, &dev_attr_active); + if (ret) + return ret; + ret = device_create_file(wdev->dev, &dev_attr_allow_disable); + if (ret) + return ret; + ret = device_create_file(wdev->dev, &dev_attr_fastmode); + if (ret) + return ret; + + return 0; +} + +static void a21_wdt_remove_files(struct watchdog_device *wdev) +{ + device_remove_file(wdev->dev, &dev_attr_rebootcause); + device_remove_file(wdev->dev, &dev_attr_active); + device_remove_file(wdev->dev, &dev_attr_allow_disable); + device_remove_file(wdev->dev, &dev_attr_fastmode); +} + +static int a21_wdt_start(struct watchdog_device *wdt) +{ + struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt); + + mutex_lock(&drv->lock); + + gpio_set_value(GPIO_WD_ENAB, 1); + + mutex_unlock(&drv->lock); + + return 0; +} + +static int a21_wdt_stop(struct watchdog_device *wdt) +{ + struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt); + + /* We don't stop if WDOG_NO_WAY_OUT is set */ + if (test_bit(WDOG_NO_WAY_OUT, &wdt->status)) + return -EINVAL; + + mutex_lock(&drv->lock); + + gpio_set_value(GPIO_WD_ENAB, 0); + + mutex_unlock(&drv->lock); + + return 0; +} + +static int a21_wdt_ping(struct watchdog_device *wdt) +{ + struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt); + + mutex_lock(&drv->lock); + + gpio_set_value(GPIO_WD_TRIG, 0); + ndelay(10); + gpio_set_value(GPIO_WD_TRIG, 1); + + mutex_unlock(&drv->lock); + + return 0; +} + +static int a21_wdt_set_timeout(struct watchdog_device *wdt, + unsigned int timeout) +{ + struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt); + + if (timeout != 1 && timeout != 30) { + dev_err(wdt->dev, "Only 1 and 30 allowed as timeout\n"); + return -EINVAL; + } + + if (timeout == 30 && wdt->timeout == 1) { + dev_err(wdt->dev, + "Transition from fast to slow mode not allowed\n"); + return -EINVAL; + } + + mutex_lock(&drv->lock); + + if (timeout == 1) + gpio_set_value(GPIO_WD_FAST, 1); + else + gpio_set_value(GPIO_WD_FAST, 0); + + wdt->timeout = timeout; + + mutex_unlock(&drv->lock); + + return 0; +} + +static int a21_wdt_notify_sys(struct notifier_block *notify, unsigned long code, + void *unused) +{ + if (code == SYS_DOWN || code == SYS_HALT) + gpio_set_value(GPIO_WD_ENAB, 0); + + return NOTIFY_DONE; +} + +static struct notifier_block a21_wdt_notifier = { + .notifier_call = a21_wdt_notify_sys, +}; + +static const struct watchdog_info a21_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, + .identity = "MEN A21 Watchdog", +}; + +static const struct watchdog_ops a21_wdt_ops = { + .owner = THIS_MODULE, + .start = a21_wdt_start, + .stop = a21_wdt_stop, + .ping = a21_wdt_ping, + .set_timeout = a21_wdt_set_timeout, +}; + +static struct watchdog_device a21_wdt = { + .info = &a21_wdt_info, + .ops = &a21_wdt_ops, + .min_timeout = 1, + .max_timeout = 30, +}; + +static int a21_wdt_probe(struct platform_device *pdev) +{ + struct a21_wdt_drv *drv; + int ret; + + dev_info(&pdev->dev, "MEN A21 watchdog timer driver enabled\n"); + + drv = devm_kzalloc(&pdev->dev, sizeof(struct a21_wdt_drv), GFP_KERNEL); + if (!drv) + return -ENOMEM; + + mutex_init(&drv->lock); + watchdog_set_nowayout(&a21_wdt, nowayout); + watchdog_set_drvdata(&a21_wdt, drv); + + ret = watchdog_register_device(&a21_wdt); + if (ret) { + dev_err(&pdev->dev, "Cannot register watchdog device\n"); + goto err_register_wd; + } + + ret = register_reboot_notifier(&a21_wdt_notifier); + if (ret) { + dev_err(&pdev->dev, "Cannot register reboot notifier\n"); + goto err_register_notif; + } + + ret = a21_wdt_create_files(&a21_wdt); + if (ret) { + dev_err(&pdev->dev, "Cannot create sysfs entries\n"); + goto err_create_sysfs; + } + + dev_set_drvdata(&pdev->dev, drv); + + return 0; + +err_create_sysfs: + unregister_reboot_notifier(&a21_wdt_notifier); +err_register_notif: + watchdog_unregister_device(&drv->wdt); +err_register_wd: + mutex_destroy(&drv->lock); + + return ret; +} + +static int a21_wdt_remove(struct platform_device *pdev) +{ + struct a21_wdt_drv *drv = dev_get_drvdata(&pdev->dev); + + dev_warn(&pdev->dev, + "Unregistering A21 watchdog driver, board may reboot\n"); + + a21_wdt_remove_files(&drv->wdt); + + watchdog_unregister_device(&drv->wdt); + unregister_reboot_notifier(&a21_wdt_notifier); + + mutex_destroy(&drv->lock); + + return 0; +} + +static const struct of_device_id a21_wdt_ids[] = { + { .compatible = "men,a021-wdt" }, + { }, +}; + +static struct platform_driver a21_wdt_driver = { + .probe = a21_wdt_probe, + .remove = a21_wdt_remove, + .driver = { + .name = "a21-watchdog", + .of_match_table = a21_wdt_ids, + }, +}; + +module_platform_driver(a21_wdt_driver); + +MODULE_AUTHOR("MEN Mikro Elektronik"); +MODULE_DESCRIPTION("MEN A21 Watchdog"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:a21-watchdog"); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/