watchdog: add driver for Cortina Gemini watchdog
This add support for the Cortina systems Gemini (SL3516) SoC watchdog. I have tried to use all the right new kernel interfaces and tested with busybox' "watchdog" command both to kick and get timeouts and reboots. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Linus Walleij
Guenter Roeck
parent
428a66554a
commit
eca10ae600
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@ -301,6 +301,17 @@ config 977_WATCHDOG
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Not sure? It's safe to say N.
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config GEMINI_WATCHDOG
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tristate "Gemini watchdog"
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depends on ARCH_GEMINI
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select WATCHDOG_CORE
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help
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Say Y here if to include support for the watchdog timer
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embedded in the Cortina Systems Gemini family of devices.
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To compile this driver as a module, choose M here: the
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module will be called gemini_wdt.
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config IXP4XX_WATCHDOG
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tristate "IXP4xx Watchdog"
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depends on ARCH_IXP4XX
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@ -45,6 +45,7 @@ obj-$(CONFIG_OMAP_WATCHDOG) += omap_wdt.o
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obj-$(CONFIG_TWL4030_WATCHDOG) += twl4030_wdt.o
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obj-$(CONFIG_21285_WATCHDOG) += wdt285.o
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obj-$(CONFIG_977_WATCHDOG) += wdt977.o
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obj-$(CONFIG_GEMINI_WATCHDOG) += gemini_wdt.o
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obj-$(CONFIG_IXP4XX_WATCHDOG) += ixp4xx_wdt.o
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obj-$(CONFIG_KS8695_WATCHDOG) += ks8695_wdt.o
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obj-$(CONFIG_S3C2410_WATCHDOG) += s3c2410_wdt.o
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@ -0,0 +1,229 @@
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/*
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* Watchdog driver for Cortina Systems Gemini SoC
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*
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* Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
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*
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* Inspired by the out-of-tree drivers from OpenWRT:
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* Copyright (C) 2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/bitops.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/of_device.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/watchdog.h>
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#define GEMINI_WDCOUNTER 0x0
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#define GEMINI_WDLOAD 0x4
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#define GEMINI_WDRESTART 0x8
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#define GEMINI_WDCR 0xC
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#define WDRESTART_MAGIC 0x5AB9
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#define WDCR_CLOCK_5MHZ BIT(4)
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#define WDCR_SYS_RST BIT(1)
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#define WDCR_ENABLE BIT(0)
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#define WDT_CLOCK 5000000 /* 5 MHz */
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struct gemini_wdt {
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struct watchdog_device wdd;
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struct device *dev;
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void __iomem *base;
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};
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static inline
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struct gemini_wdt *to_gemini_wdt(struct watchdog_device *wdd)
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{
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return container_of(wdd, struct gemini_wdt, wdd);
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}
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static int gemini_wdt_start(struct watchdog_device *wdd)
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{
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struct gemini_wdt *gwdt = to_gemini_wdt(wdd);
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writel(wdd->timeout * WDT_CLOCK, gwdt->base + GEMINI_WDLOAD);
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writel(WDRESTART_MAGIC, gwdt->base + GEMINI_WDRESTART);
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/* set clock before enabling */
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writel(WDCR_CLOCK_5MHZ | WDCR_SYS_RST,
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gwdt->base + GEMINI_WDCR);
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writel(WDCR_CLOCK_5MHZ | WDCR_SYS_RST | WDCR_ENABLE,
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gwdt->base + GEMINI_WDCR);
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return 0;
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}
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static int gemini_wdt_stop(struct watchdog_device *wdd)
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{
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struct gemini_wdt *gwdt = to_gemini_wdt(wdd);
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writel(0, gwdt->base + GEMINI_WDCR);
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return 0;
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}
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static int gemini_wdt_ping(struct watchdog_device *wdd)
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{
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struct gemini_wdt *gwdt = to_gemini_wdt(wdd);
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writel(WDRESTART_MAGIC, gwdt->base + GEMINI_WDRESTART);
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return 0;
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}
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static int gemini_wdt_set_timeout(struct watchdog_device *wdd,
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unsigned int timeout)
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{
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wdd->timeout = timeout;
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if (watchdog_active(wdd))
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gemini_wdt_start(wdd);
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return 0;
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}
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static irqreturn_t gemini_wdt_interrupt(int irq, void *data)
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{
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struct gemini_wdt *gwdt = data;
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watchdog_notify_pretimeout(&gwdt->wdd);
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return IRQ_HANDLED;
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}
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static const struct watchdog_ops gemini_wdt_ops = {
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.start = gemini_wdt_start,
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.stop = gemini_wdt_stop,
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.ping = gemini_wdt_ping,
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.set_timeout = gemini_wdt_set_timeout,
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.owner = THIS_MODULE,
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};
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static const struct watchdog_info gemini_wdt_info = {
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.options = WDIOF_KEEPALIVEPING
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| WDIOF_MAGICCLOSE
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| WDIOF_SETTIMEOUT,
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.identity = KBUILD_MODNAME,
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};
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static int gemini_wdt_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct resource *res;
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struct gemini_wdt *gwdt;
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unsigned int reg;
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int irq;
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int ret;
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gwdt = devm_kzalloc(dev, sizeof(*gwdt), GFP_KERNEL);
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if (!gwdt)
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return -ENOMEM;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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gwdt->base = devm_ioremap_resource(dev, res);
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if (IS_ERR(gwdt->base))
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return PTR_ERR(gwdt->base);
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irq = platform_get_irq(pdev, 0);
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if (!irq)
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return -EINVAL;
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gwdt->dev = dev;
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gwdt->wdd.info = &gemini_wdt_info;
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gwdt->wdd.ops = &gemini_wdt_ops;
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gwdt->wdd.min_timeout = 1;
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gwdt->wdd.max_timeout = 0xFFFFFFFF / WDT_CLOCK;
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gwdt->wdd.parent = dev;
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/*
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* If 'timeout-sec' unspecified in devicetree, assume a 13 second
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* default.
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*/
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gwdt->wdd.timeout = 13U;
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watchdog_init_timeout(&gwdt->wdd, 0, dev);
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reg = readw(gwdt->base + GEMINI_WDCR);
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if (reg & WDCR_ENABLE) {
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/* Watchdog was enabled by the bootloader, disable it. */
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reg &= ~WDCR_ENABLE;
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writel(reg, gwdt->base + GEMINI_WDCR);
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}
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ret = devm_request_irq(dev, irq, gemini_wdt_interrupt, 0,
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"watchdog bark", gwdt);
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if (ret)
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return ret;
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ret = devm_watchdog_register_device(dev, &gwdt->wdd);
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if (ret) {
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dev_err(&pdev->dev, "failed to register watchdog\n");
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return ret;
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}
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/* Set up platform driver data */
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platform_set_drvdata(pdev, gwdt);
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dev_info(dev, "Gemini watchdog driver enabled\n");
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return 0;
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}
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static int __maybe_unused gemini_wdt_suspend(struct device *dev)
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{
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struct gemini_wdt *gwdt = dev_get_drvdata(dev);
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unsigned int reg;
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reg = readw(gwdt->base + GEMINI_WDCR);
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reg &= ~WDCR_ENABLE;
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writel(reg, gwdt->base + GEMINI_WDCR);
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return 0;
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}
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static int __maybe_unused gemini_wdt_resume(struct device *dev)
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{
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struct gemini_wdt *gwdt = dev_get_drvdata(dev);
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unsigned int reg;
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if (watchdog_active(&gwdt->wdd)) {
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reg = readw(gwdt->base + GEMINI_WDCR);
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reg |= WDCR_ENABLE;
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writel(reg, gwdt->base + GEMINI_WDCR);
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}
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return 0;
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}
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static const struct dev_pm_ops gemini_wdt_dev_pm_ops = {
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SET_SYSTEM_SLEEP_PM_OPS(gemini_wdt_suspend,
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gemini_wdt_resume)
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};
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#ifdef CONFIG_OF
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static const struct of_device_id gemini_wdt_match[] = {
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{ .compatible = "cortina,gemini-watchdog" },
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{},
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};
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MODULE_DEVICE_TABLE(of, gemini_wdt_match);
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#endif
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static struct platform_driver gemini_wdt_driver = {
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.probe = gemini_wdt_probe,
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.driver = {
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.name = "gemini-wdt",
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.of_match_table = of_match_ptr(gemini_wdt_match),
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.pm = &gemini_wdt_dev_pm_ops,
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},
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};
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module_platform_driver(gemini_wdt_driver);
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MODULE_AUTHOR("Linus Walleij");
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MODULE_DESCRIPTION("Watchdog driver for Gemini");
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MODULE_LICENSE("GPL");
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