Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752625Ab3C0Qkg (ORCPT ); Wed, 27 Mar 2013 12:40:36 -0400 Received: from norkia.v3.sk ([91.210.183.14]:34964 "EHLO norkia.v3.sk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751873Ab3C0Qke (ORCPT ); Wed, 27 Mar 2013 12:40:34 -0400 From: Lubomir Rintel To: linux-kernel@vger.kernel.org Cc: Lubomir Rintel , Dom Cobley , Stephen Warren , Wim Van Sebroeck , Guenter Roeck , linux-rpi-kernel@lists.infradead.org, linux-watchdog@vger.kernel.org Subject: [PATCH v4] watchdog: Add Broadcom BCM2835 watchdog timer driver Date: Wed, 27 Mar 2013 17:40:24 +0100 Message-Id: <1364402424-19503-1-git-send-email-lkundrak@v3.sk> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1364320200-23569-1-git-send-email-lkundrak@v3.sk> References: <1364320200-23569-1-git-send-email-lkundrak@v3.sk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9206 Lines: 296 This adds a driver for watchdog timer hardware present on Broadcom BCM2835 SoC, used in Raspberry Pi and Roku 2 devices. Signed-off-by: Lubomir Rintel Signed-off-by: Dom Cobley Tested-by: Stephen Warren Cc: Stephen Warren Cc: Wim Van Sebroeck Cc: Guenter Roeck Cc: linux-rpi-kernel@lists.infradead.org Cc: linux-watchdog@vger.kernel.org --- Changes for v2: - Use per-device structure instead of global variables for lock and memory base - Fix default timeout setting - Do not leak memory if probe fails - Style fixes - Split out defconfig into a separate commit - Meaningful commit message with credit Changes for v3: - Add proper copyright notice to header - Drop status constants, we don't use them - Fix heartbeat parameter's type - Log driver initialization message once the device is probed Changes for v4: - Drop an useless initializer - Add a signoff from downstream - Do not announce the driver to the log if we failed to probe - Set platform data earlier and do not explicitly unset it .../bindings/watchdog/brcm,bcm2835-pm-wdog.txt | 5 + drivers/watchdog/Kconfig | 11 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/bcm2835_wdt.c | 190 ++++++++++++++++++++ 4 files changed, 207 insertions(+), 0 deletions(-) create mode 100644 drivers/watchdog/bcm2835_wdt.c diff --git a/Documentation/devicetree/bindings/watchdog/brcm,bcm2835-pm-wdog.txt b/Documentation/devicetree/bindings/watchdog/brcm,bcm2835-pm-wdog.txt index d209366..f801d71 100644 --- a/Documentation/devicetree/bindings/watchdog/brcm,bcm2835-pm-wdog.txt +++ b/Documentation/devicetree/bindings/watchdog/brcm,bcm2835-pm-wdog.txt @@ -5,9 +5,14 @@ Required properties: - compatible : should be "brcm,bcm2835-pm-wdt" - reg : Specifies base physical address and size of the registers. +Optional properties: + +- timeout-sec : Contains the watchdog timeout in seconds + Example: watchdog { compatible = "brcm,bcm2835-pm-wdt"; reg = <0x7e100000 0x28>; + timeout-sec = <10>; }; diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 9fcc70c..f4e4a8e 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1098,6 +1098,17 @@ config BCM63XX_WDT To compile this driver as a loadable module, choose M here. The module will be called bcm63xx_wdt. +config BCM2835_WDT + tristate "Broadcom BCM2835 hardware watchdog" + depends on ARCH_BCM2835 + select WATCHDOG_CORE + help + Watchdog driver for the built in watchdog hardware in Broadcom + BCM2835 SoC. + + To compile this driver as a loadable module, choose M here. + The module will be called bcm2835_wdt. + config LANTIQ_WDT tristate "Lantiq SoC watchdog" depends on LANTIQ diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index a300b94..1bf5675 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -54,6 +54,7 @@ obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_wdt.o obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o +obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o # AVR32 Architecture obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o diff --git a/drivers/watchdog/bcm2835_wdt.c b/drivers/watchdog/bcm2835_wdt.c new file mode 100644 index 0000000..d47c842 --- /dev/null +++ b/drivers/watchdog/bcm2835_wdt.c @@ -0,0 +1,190 @@ +/* + * Watchdog driver for Broadcom BCM2835 + * + * Interface to the Broadcom BCM2835 watchdog timer hardware is based on + * "bcm2708_wdog" driver written by Luke Diamand that was obtained from branch + * "rpi-3.6.y" of git://github.com/raspberrypi/linux.git + * + * (c) Copyright 2010 Broadcom Europe Ltd + * Copyright (C) 2013 Lubomir Rintel + * + * 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; either version + * 2 of the License, or (at your option) any later version. + */ + +#include +#include +#include +#include +#include +#include +#include + +#define PM_RSTC 0x1c +#define PM_WDOG 0x24 + +#define PM_PASSWORD 0x5a000000 + +#define PM_WDOG_TIME_SET 0x000fffff +#define PM_RSTC_WRCFG_CLR 0xffffffcf +#define PM_RSTC_WRCFG_SET 0x00000030 +#define PM_RSTC_WRCFG_FULL_RESET 0x00000020 +#define PM_RSTC_RESET 0x00000102 + +#define SECS_TO_WDOG_TICKS(x) ((x) << 16) +#define WDOG_TICKS_TO_SECS(x) ((x) >> 16) + +struct bcm2835_wdt { + void __iomem *base; + spinlock_t lock; +}; + +static unsigned int heartbeat; +static bool nowayout = WATCHDOG_NOWAYOUT; + +static int bcm2835_wdt_start(struct watchdog_device *wdog) +{ + struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog); + uint32_t cur; + unsigned long flags; + + spin_lock_irqsave(&wdt->lock, flags); + + writel_relaxed(PM_PASSWORD | (SECS_TO_WDOG_TICKS(wdog->timeout) & + PM_WDOG_TIME_SET), wdt->base + PM_WDOG); + cur = readl_relaxed(wdt->base + PM_RSTC); + writel_relaxed(PM_PASSWORD | (cur & PM_RSTC_WRCFG_CLR) | + PM_RSTC_WRCFG_FULL_RESET, wdt->base + PM_RSTC); + + spin_unlock_irqrestore(&wdt->lock, flags); + + return 0; +} + +static int bcm2835_wdt_stop(struct watchdog_device *wdog) +{ + struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog); + + writel_relaxed(PM_PASSWORD | PM_RSTC_RESET, wdt->base + PM_RSTC); + dev_info(wdog->dev, "Watchdog timer stopped"); + return 0; +} + +static int bcm2835_wdt_set_timeout(struct watchdog_device *wdog, unsigned int t) +{ + wdog->timeout = t; + return 0; +} + +static unsigned int bcm2835_wdt_get_timeleft(struct watchdog_device *wdog) +{ + struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog); + + uint32_t ret = readl_relaxed(wdt->base + PM_WDOG); + return WDOG_TICKS_TO_SECS(ret & PM_WDOG_TIME_SET); +} + +static struct watchdog_ops bcm2835_wdt_ops = { + .owner = THIS_MODULE, + .start = bcm2835_wdt_start, + .stop = bcm2835_wdt_stop, + .set_timeout = bcm2835_wdt_set_timeout, + .get_timeleft = bcm2835_wdt_get_timeleft, +}; + +static struct watchdog_info bcm2835_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | + WDIOF_KEEPALIVEPING, + .identity = "Broadcom BCM2835 Watchdog timer", +}; + +static struct watchdog_device bcm2835_wdt_wdd = { + .info = &bcm2835_wdt_info, + .ops = &bcm2835_wdt_ops, + .min_timeout = 1, + .max_timeout = WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET), + .timeout = WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET), +}; + +static int bcm2835_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct bcm2835_wdt *wdt; + int err; + + wdt = devm_kzalloc(dev, sizeof(struct bcm2835_wdt), GFP_KERNEL); + if (!wdt) { + dev_err(dev, "Failed to allocate memory for watchdog device"); + return -ENOMEM; + } + platform_set_drvdata(pdev, wdt); + + spin_lock_init(&wdt->lock); + + wdt->base = of_iomap(np, 0); + if (!wdt->base) { + dev_err(dev, "Failed to remap watchdog regs"); + return -ENODEV; + } + + watchdog_set_drvdata(&bcm2835_wdt_wdd, wdt); + watchdog_init_timeout(&bcm2835_wdt_wdd, heartbeat, dev); + watchdog_set_nowayout(&bcm2835_wdt_wdd, nowayout); + err = watchdog_register_device(&bcm2835_wdt_wdd); + if (err) { + dev_err(dev, "Failed to register watchdog device"); + iounmap(wdt->base); + return err; + } + + dev_info(dev, "Broadcom BCM2835 watchdog timer"); + return 0; +} + +static int bcm2835_wdt_remove(struct platform_device *pdev) +{ + struct bcm2835_wdt *wdt = platform_get_drvdata(pdev); + + watchdog_unregister_device(&bcm2835_wdt_wdd); + iounmap(wdt->base); + + return 0; +} + +static void bcm2835_wdt_shutdown(struct platform_device *pdev) +{ + bcm2835_wdt_stop(&bcm2835_wdt_wdd); +} + +static const struct of_device_id bcm2835_wdt_of_match[] = { + { .compatible = "brcm,bcm2835-pm-wdt", }, + {}, +}; +MODULE_DEVICE_TABLE(of, bcm2835_wdt_of_match); + +static struct platform_driver bcm2835_wdt_driver = { + .probe = bcm2835_wdt_probe, + .remove = bcm2835_wdt_remove, + .shutdown = bcm2835_wdt_shutdown, + .driver = { + .name = "bcm2835-wdt", + .owner = THIS_MODULE, + .of_match_table = bcm2835_wdt_of_match, + }, +}; +module_platform_driver(bcm2835_wdt_driver); + +module_param(heartbeat, uint, 0); +MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds"); + +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +MODULE_AUTHOR("Lubomir Rintel "); +MODULE_DESCRIPTION("Driver for Broadcom BCM2835 watchdog timer"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); -- 1.7.1 -- 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/