Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753514Ab3CZVDk (ORCPT ); Tue, 26 Mar 2013 17:03:40 -0400 Received: from mail.active-venture.com ([67.228.131.205]:64333 "EHLO mail.active-venture.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751303Ab3CZVDi (ORCPT ); Tue, 26 Mar 2013 17:03:38 -0400 X-Originating-IP: 108.223.40.66 Date: Tue, 26 Mar 2013 14:03:48 -0700 From: Guenter Roeck To: Lubomir Rintel Cc: linux-kernel@vger.kernel.org, Stephen Warren , Wim Van Sebroeck , linux-rpi-kernel@lists.infradead.org, linux-watchdog@vger.kernel.org Subject: Re: [PATCH v3] watchdog: Add Broadcom BCM2835 watchdog timer driver Message-ID: <20130326210348.GA23436@roeck-us.net> References: <1364135137-26691-1-git-send-email-lkundrak@v3.sk> <1364320200-23569-1-git-send-email-lkundrak@v3.sk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1364320200-23569-1-git-send-email-lkundrak@v3.sk> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8697 Lines: 262 On Tue, Mar 26, 2013 at 06:50:00PM +0100, Lubomir Rintel wrote: > 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 > 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 > > .../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..13a8c00 > --- /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 = 0; checkpatch.pl says: ERROR: do not initialise statics to 0 or NULL #178: FILE: drivers/watchdog/bcm2835_wdt.c:44: +static unsigned int heartbeat = 0; > +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; > + } > + > + spin_lock_init(&wdt->lock); > + > + wdt->base = of_iomap(np, 0); > + if (!wdt->base) { > + dev_err(dev, "Failed to remap watchdog regs"); > + return -ENODEV; > + } > + > + platform_set_drvdata(pdev, wdt); > + 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); > + } > + dev_info(dev, "Broadcom BCM2835 watchdog timer"); > + Hmm .. that means you'll get the info message even in the error case. Is that intentional ? It is inconsistent with the remap error message above, which does not result in the info message. > + return err; > +} > + > +static int bcm2835_wdt_remove(struct platform_device *pdev) > +{ > + struct bcm2835_wdt *wdt = platform_get_drvdata(pdev); > + > + platform_set_drvdata(pdev, NULL); Still unnecessary. Thanks, Guenter -- 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/