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81df6db681
Use device managed functions to simplify error handling, reduce source code size, improve readability, and reduce the likelyhood of bugs. Other improvements as listed below. The conversion was done automatically with coccinelle using the following semantic patches. The semantic patches and the scripts used to generate this commit log are available at https://github.com/groeck/coccinelle-patches - Drop assignments to otherwise unused variables - Drop empty remove function This also drops the inaccurate message on remove; the driver won't be removed if the hardware watchdog is running, no matter if the watchdog device is open or not. - Use local variable 'struct device *dev' consistently - Use devm_watchdog_register_driver() to register watchdog device Signed-off-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
274 lines
7.1 KiB
C
274 lines
7.1 KiB
C
/*
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* mpc8xxx_wdt.c - MPC8xx/MPC83xx/MPC86xx watchdog userspace interface
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*
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* Authors: Dave Updegraff <dave@cray.org>
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* Kumar Gala <galak@kernel.crashing.org>
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* Attribution: from 83xx_wst: Florian Schirmer <jolt@tuxbox.org>
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* ..and from sc520_wdt
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* Copyright (c) 2008 MontaVista Software, Inc.
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* Anton Vorontsov <avorontsov@ru.mvista.com>
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*
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* Note: it appears that you can only actually ENABLE or DISABLE the thing
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* once after POR. Once enabled, you cannot disable, and vice versa.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*/
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#include <linux/fs.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/of_address.h>
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#include <linux/of_platform.h>
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#include <linux/module.h>
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#include <linux/watchdog.h>
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#include <linux/io.h>
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#include <linux/uaccess.h>
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#include <sysdev/fsl_soc.h>
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#define WATCHDOG_TIMEOUT 10
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struct mpc8xxx_wdt {
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__be32 res0;
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__be32 swcrr; /* System watchdog control register */
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#define SWCRR_SWTC 0xFFFF0000 /* Software Watchdog Time Count. */
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#define SWCRR_SWF 0x00000008 /* Software Watchdog Freeze (mpc8xx). */
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#define SWCRR_SWEN 0x00000004 /* Watchdog Enable bit. */
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#define SWCRR_SWRI 0x00000002 /* Software Watchdog Reset/Interrupt Select bit.*/
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#define SWCRR_SWPR 0x00000001 /* Software Watchdog Counter Prescale bit. */
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__be32 swcnr; /* System watchdog count register */
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u8 res1[2];
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__be16 swsrr; /* System watchdog service register */
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u8 res2[0xF0];
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};
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struct mpc8xxx_wdt_type {
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int prescaler;
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bool hw_enabled;
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u32 rsr_mask;
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};
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struct mpc8xxx_wdt_ddata {
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struct mpc8xxx_wdt __iomem *base;
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struct watchdog_device wdd;
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spinlock_t lock;
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u16 swtc;
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};
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static u16 timeout;
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module_param(timeout, ushort, 0);
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MODULE_PARM_DESC(timeout,
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"Watchdog timeout in seconds. (1<timeout<65535, default="
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__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
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static bool reset = 1;
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module_param(reset, bool, 0);
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MODULE_PARM_DESC(reset,
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"Watchdog Interrupt/Reset Mode. 0 = interrupt, 1 = reset");
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static bool nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, bool, 0);
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
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"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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static void mpc8xxx_wdt_keepalive(struct mpc8xxx_wdt_ddata *ddata)
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{
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/* Ping the WDT */
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spin_lock(&ddata->lock);
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out_be16(&ddata->base->swsrr, 0x556c);
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out_be16(&ddata->base->swsrr, 0xaa39);
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spin_unlock(&ddata->lock);
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}
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static int mpc8xxx_wdt_start(struct watchdog_device *w)
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{
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struct mpc8xxx_wdt_ddata *ddata =
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container_of(w, struct mpc8xxx_wdt_ddata, wdd);
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u32 tmp = in_be32(&ddata->base->swcrr);
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/* Good, fire up the show */
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tmp &= ~(SWCRR_SWTC | SWCRR_SWF | SWCRR_SWEN | SWCRR_SWRI | SWCRR_SWPR);
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tmp |= SWCRR_SWEN | SWCRR_SWPR | (ddata->swtc << 16);
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if (reset)
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tmp |= SWCRR_SWRI;
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out_be32(&ddata->base->swcrr, tmp);
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tmp = in_be32(&ddata->base->swcrr);
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if (!(tmp & SWCRR_SWEN))
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return -EOPNOTSUPP;
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ddata->swtc = tmp >> 16;
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set_bit(WDOG_HW_RUNNING, &ddata->wdd.status);
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return 0;
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}
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static int mpc8xxx_wdt_ping(struct watchdog_device *w)
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{
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struct mpc8xxx_wdt_ddata *ddata =
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container_of(w, struct mpc8xxx_wdt_ddata, wdd);
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mpc8xxx_wdt_keepalive(ddata);
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return 0;
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}
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static struct watchdog_info mpc8xxx_wdt_info = {
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.options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT,
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.firmware_version = 1,
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.identity = "MPC8xxx",
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};
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static struct watchdog_ops mpc8xxx_wdt_ops = {
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.owner = THIS_MODULE,
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.start = mpc8xxx_wdt_start,
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.ping = mpc8xxx_wdt_ping,
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};
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static int mpc8xxx_wdt_probe(struct platform_device *ofdev)
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{
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int ret;
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struct resource *res;
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const struct mpc8xxx_wdt_type *wdt_type;
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struct mpc8xxx_wdt_ddata *ddata;
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u32 freq = fsl_get_sys_freq();
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bool enabled;
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struct device *dev = &ofdev->dev;
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wdt_type = of_device_get_match_data(dev);
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if (!wdt_type)
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return -EINVAL;
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if (!freq || freq == -1)
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return -EINVAL;
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ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
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if (!ddata)
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return -ENOMEM;
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ddata->base = devm_platform_ioremap_resource(ofdev, 0);
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if (IS_ERR(ddata->base))
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return PTR_ERR(ddata->base);
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enabled = in_be32(&ddata->base->swcrr) & SWCRR_SWEN;
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if (!enabled && wdt_type->hw_enabled) {
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dev_info(dev, "could not be enabled in software\n");
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return -ENODEV;
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}
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res = platform_get_resource(ofdev, IORESOURCE_MEM, 1);
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if (res) {
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bool status;
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u32 __iomem *rsr = ioremap(res->start, resource_size(res));
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if (!rsr)
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return -ENOMEM;
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status = in_be32(rsr) & wdt_type->rsr_mask;
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ddata->wdd.bootstatus = status ? WDIOF_CARDRESET : 0;
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/* clear reset status bits related to watchdog timer */
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out_be32(rsr, wdt_type->rsr_mask);
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iounmap(rsr);
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dev_info(dev, "Last boot was %scaused by watchdog\n",
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status ? "" : "not ");
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}
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spin_lock_init(&ddata->lock);
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ddata->wdd.info = &mpc8xxx_wdt_info,
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ddata->wdd.ops = &mpc8xxx_wdt_ops,
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ddata->wdd.timeout = WATCHDOG_TIMEOUT;
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watchdog_init_timeout(&ddata->wdd, timeout, dev);
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watchdog_set_nowayout(&ddata->wdd, nowayout);
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ddata->swtc = min(ddata->wdd.timeout * freq / wdt_type->prescaler,
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0xffffU);
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/*
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* If the watchdog was previously enabled or we're running on
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* MPC8xxx, we should ping the wdt from the kernel until the
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* userspace handles it.
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*/
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if (enabled)
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mpc8xxx_wdt_start(&ddata->wdd);
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ddata->wdd.max_hw_heartbeat_ms = (ddata->swtc * wdt_type->prescaler) /
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(freq / 1000);
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ddata->wdd.min_timeout = ddata->wdd.max_hw_heartbeat_ms / 1000;
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if (ddata->wdd.timeout < ddata->wdd.min_timeout)
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ddata->wdd.timeout = ddata->wdd.min_timeout;
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ret = devm_watchdog_register_device(dev, &ddata->wdd);
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if (ret) {
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dev_err(dev, "cannot register watchdog device (err=%d)\n",
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ret);
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return ret;
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}
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dev_info(dev,
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"WDT driver for MPC8xxx initialized. mode:%s timeout=%d sec\n",
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reset ? "reset" : "interrupt", ddata->wdd.timeout);
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platform_set_drvdata(ofdev, ddata);
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return 0;
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}
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static const struct of_device_id mpc8xxx_wdt_match[] = {
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{
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.compatible = "mpc83xx_wdt",
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.data = &(struct mpc8xxx_wdt_type) {
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.prescaler = 0x10000,
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.rsr_mask = BIT(3), /* RSR Bit SWRS */
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},
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},
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{
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.compatible = "fsl,mpc8610-wdt",
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.data = &(struct mpc8xxx_wdt_type) {
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.prescaler = 0x10000,
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.hw_enabled = true,
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.rsr_mask = BIT(20), /* RSTRSCR Bit WDT_RR */
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},
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},
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{
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.compatible = "fsl,mpc823-wdt",
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.data = &(struct mpc8xxx_wdt_type) {
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.prescaler = 0x800,
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.hw_enabled = true,
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.rsr_mask = BIT(28), /* RSR Bit SWRS */
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},
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},
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{},
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};
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MODULE_DEVICE_TABLE(of, mpc8xxx_wdt_match);
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static struct platform_driver mpc8xxx_wdt_driver = {
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.probe = mpc8xxx_wdt_probe,
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.driver = {
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.name = "mpc8xxx_wdt",
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.of_match_table = mpc8xxx_wdt_match,
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},
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};
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static int __init mpc8xxx_wdt_init(void)
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{
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return platform_driver_register(&mpc8xxx_wdt_driver);
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}
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arch_initcall(mpc8xxx_wdt_init);
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static void __exit mpc8xxx_wdt_exit(void)
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{
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platform_driver_unregister(&mpc8xxx_wdt_driver);
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}
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module_exit(mpc8xxx_wdt_exit);
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MODULE_AUTHOR("Dave Updegraff, Kumar Gala");
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MODULE_DESCRIPTION("Driver for watchdog timer in MPC8xx/MPC83xx/MPC86xx "
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"uProcessors");
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MODULE_LICENSE("GPL");
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