cregit-Linux how code gets into the kernel

Release 4.10 drivers/watchdog/mpc8xxx_wdt.c

Directory: drivers/watchdog
/*
 * mpc8xxx_wdt.c - MPC8xx/MPC83xx/MPC86xx watchdog userspace interface
 *
 * Authors: Dave Updegraff <dave@cray.org>
 *          Kumar Gala <galak@kernel.crashing.org>
 *              Attribution: from 83xx_wst: Florian Schirmer <jolt@tuxbox.org>
 *                              ..and from sc520_wdt
 * Copyright (c) 2008  MontaVista Software, Inc.
 *                     Anton Vorontsov <avorontsov@ru.mvista.com>
 *
 * Note: it appears that you can only actually ENABLE or DISABLE the thing
 * once after POR. Once enabled, you cannot disable, and vice versa.
 *
 * 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.
 */


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/module.h>
#include <linux/watchdog.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <sysdev/fsl_soc.h>


struct mpc8xxx_wdt {
	
__be32 res0;
	
__be32 swcrr; /* System watchdog control register */

#define SWCRR_SWTC 0xFFFF0000 /* Software Watchdog Time Count. */

#define SWCRR_SWEN 0x00000004 /* Watchdog Enable bit. */

#define SWCRR_SWRI 0x00000002 /* Software Watchdog Reset/Interrupt Select bit.*/

#define SWCRR_SWPR 0x00000001 /* Software Watchdog Counter Prescale bit. */
	
__be32 swcnr; /* System watchdog count register */
	
u8 res1[2];
	
__be16 swsrr; /* System watchdog service register */
	
u8 res2[0xF0];
};


struct mpc8xxx_wdt_type {
	
int prescaler;
	
bool hw_enabled;
};


struct mpc8xxx_wdt_ddata {
	
struct mpc8xxx_wdt __iomem *base;
	
struct watchdog_device wdd;
	
struct timer_list timer;
	
spinlock_t lock;
};


static u16 timeout = 0xffff;
module_param(timeout, ushort, 0);
MODULE_PARM_DESC(timeout,
	"Watchdog timeout in ticks. (0<timeout<65536, default=65535)");


static bool reset = 1;
module_param(reset, bool, 0);
MODULE_PARM_DESC(reset,
	"Watchdog Interrupt/Reset Mode. 0 = interrupt, 1 = reset");


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 void mpc8xxx_wdt_keepalive(struct mpc8xxx_wdt_ddata *ddata) { /* Ping the WDT */ spin_lock(&ddata->lock); out_be16(&ddata->base->swsrr, 0x556c); out_be16(&ddata->base->swsrr, 0xaa39); spin_unlock(&ddata->lock); }

Contributors

PersonTokensPropCommitsCommitProp
kumar galakumar gala3567.31%133.33%
uwe kleine-koeniguwe kleine-koenig1630.77%133.33%
anton vorontsovanton vorontsov11.92%133.33%
Total52100.00%3100.00%


static void mpc8xxx_wdt_timer_ping(unsigned long arg) { struct mpc8xxx_wdt_ddata *ddata = (void *)arg; mpc8xxx_wdt_keepalive(ddata); /* We're pinging it twice faster than needed, just to be sure. */ mod_timer(&ddata->timer, jiffies + HZ * ddata->wdd.timeout / 2); }

Contributors

PersonTokensPropCommitsCommitProp
anton vorontsovanton vorontsov2553.19%250.00%
uwe kleine-koeniguwe kleine-koenig1225.53%125.00%
christophe leroychristophe leroy1021.28%125.00%
Total47100.00%4100.00%


static int mpc8xxx_wdt_start(struct watchdog_device *w) { struct mpc8xxx_wdt_ddata *ddata = container_of(w, struct mpc8xxx_wdt_ddata, wdd); u32 tmp = SWCRR_SWEN | SWCRR_SWPR; /* Good, fire up the show */ if (reset) tmp |= SWCRR_SWRI; tmp |= timeout << 16; out_be32(&ddata->base->swcrr, tmp); del_timer_sync(&ddata->timer); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
kumar galakumar gala3954.93%120.00%
uwe kleine-koeniguwe kleine-koenig2332.39%240.00%
anton vorontsovanton vorontsov57.04%120.00%
christophe leroychristophe leroy45.63%120.00%
Total71100.00%5100.00%


static int mpc8xxx_wdt_ping(struct watchdog_device *w) { struct mpc8xxx_wdt_ddata *ddata = container_of(w, struct mpc8xxx_wdt_ddata, wdd); mpc8xxx_wdt_keepalive(ddata); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
uwe kleine-koeniguwe kleine-koenig1852.94%133.33%
kumar galakumar gala1235.29%133.33%
christophe leroychristophe leroy411.76%133.33%
Total34100.00%3100.00%


static int mpc8xxx_wdt_stop(struct watchdog_device *w) { struct mpc8xxx_wdt_ddata *ddata = container_of(w, struct mpc8xxx_wdt_ddata, wdd); mod_timer(&ddata->timer, jiffies); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
uwe kleine-koeniguwe kleine-koenig1846.15%133.33%
christophe leroychristophe leroy1538.46%133.33%
kumar galakumar gala615.38%133.33%
Total39100.00%3100.00%

static struct watchdog_info mpc8xxx_wdt_info = { .options = WDIOF_KEEPALIVEPING, .firmware_version = 1, .identity = "MPC8xxx", }; static struct watchdog_ops mpc8xxx_wdt_ops = { .owner = THIS_MODULE, .start = mpc8xxx_wdt_start, .ping = mpc8xxx_wdt_ping, .stop = mpc8xxx_wdt_stop, };
static int mpc8xxx_wdt_probe(struct platform_device *ofdev) { int ret; struct resource *res; const struct mpc8xxx_wdt_type *wdt_type; struct mpc8xxx_wdt_ddata *ddata; u32 freq = fsl_get_sys_freq(); bool enabled; unsigned int timeout_sec; wdt_type = of_device_get_match_data(&ofdev->dev); if (!wdt_type) return -EINVAL; if (!freq || freq == -1) return -EINVAL; ddata = devm_kzalloc(&ofdev->dev, sizeof(*ddata), GFP_KERNEL); if (!ddata) return -ENOMEM; res = platform_get_resource(ofdev, IORESOURCE_MEM, 0); ddata->base = devm_ioremap_resource(&ofdev->dev, res); if (IS_ERR(ddata->base)) return PTR_ERR(ddata->base); enabled = in_be32(&ddata->base->swcrr) & SWCRR_SWEN; if (!enabled && wdt_type->hw_enabled) { pr_info("could not be enabled in software\n"); return -ENODEV; } spin_lock_init(&ddata->lock); setup_timer(&ddata->timer, mpc8xxx_wdt_timer_ping, (unsigned long)ddata); ddata->wdd.info = &mpc8xxx_wdt_info, ddata->wdd.ops = &mpc8xxx_wdt_ops, /* Calculate the timeout in seconds */ timeout_sec = (timeout * wdt_type->prescaler) / freq; ddata->wdd.timeout = timeout_sec; watchdog_set_nowayout(&ddata->wdd, nowayout); ret = watchdog_register_device(&ddata->wdd); if (ret) { pr_err("cannot register watchdog device (err=%d)\n", ret); return ret; } pr_info("WDT driver for MPC8xxx initialized. mode:%s timeout=%d (%d seconds)\n", reset ? "reset" : "interrupt", timeout, timeout_sec); /* * If the watchdog was previously enabled or we're running on * MPC8xxx, we should ping the wdt from the kernel until the * userspace handles it. */ if (enabled) mod_timer(&ddata->timer, jiffies); platform_set_drvdata(ofdev, ddata); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
uwe kleine-koeniguwe kleine-koenig15849.69%531.25%
anton vorontsovanton vorontsov7623.90%425.00%
kumar galakumar gala4815.09%16.25%
grant likelygrant likely206.29%318.75%
christophe leroychristophe leroy134.09%16.25%
joe perchesjoe perches20.63%16.25%
arnd bergmannarnd bergmann10.31%16.25%
Total318100.00%16100.00%


static int mpc8xxx_wdt_remove(struct platform_device *ofdev) { struct mpc8xxx_wdt_ddata *ddata = platform_get_drvdata(ofdev); pr_crit("Watchdog removed, expect the %s soon!\n", reset ? "reset" : "machine check exception"); del_timer_sync(&ddata->timer); watchdog_unregister_device(&ddata->wdd); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
uwe kleine-koeniguwe kleine-koenig1631.37%114.29%
kumar galakumar gala1529.41%114.29%
anton vorontsovanton vorontsov1019.61%342.86%
christophe leroychristophe leroy917.65%114.29%
grant likelygrant likely11.96%114.29%
Total51100.00%7100.00%

static const struct of_device_id mpc8xxx_wdt_match[] = { { .compatible = "mpc83xx_wdt", .data = &(struct mpc8xxx_wdt_type) { .prescaler = 0x10000, }, }, { .compatible = "fsl,mpc8610-wdt", .data = &(struct mpc8xxx_wdt_type) { .prescaler = 0x10000, .hw_enabled = true, }, }, { .compatible = "fsl,mpc823-wdt", .data = &(struct mpc8xxx_wdt_type) { .prescaler = 0x800, .hw_enabled = true, }, }, {}, }; MODULE_DEVICE_TABLE(of, mpc8xxx_wdt_match); static struct platform_driver mpc8xxx_wdt_driver = { .probe = mpc8xxx_wdt_probe, .remove = mpc8xxx_wdt_remove, .driver = { .name = "mpc8xxx_wdt", .of_match_table = mpc8xxx_wdt_match, }, };
static int __init mpc8xxx_wdt_init(void) { return platform_driver_register(&mpc8xxx_wdt_driver); }

Contributors

PersonTokensPropCommitsCommitProp
kumar galakumar gala1381.25%133.33%
anton vorontsovanton vorontsov212.50%133.33%
grant likelygrant likely16.25%133.33%
Total16100.00%3100.00%

arch_initcall(mpc8xxx_wdt_init);
static void __exit mpc8xxx_wdt_exit(void) { platform_driver_unregister(&mpc8xxx_wdt_driver); }

Contributors

PersonTokensPropCommitsCommitProp
kumar galakumar gala1280.00%133.33%
anton vorontsovanton vorontsov213.33%133.33%
grant likelygrant likely16.67%133.33%
Total15100.00%3100.00%

module_exit(mpc8xxx_wdt_exit); MODULE_AUTHOR("Dave Updegraff, Kumar Gala"); MODULE_DESCRIPTION("Driver for watchdog timer in MPC8xx/MPC83xx/MPC86xx " "uProcessors"); MODULE_LICENSE("GPL");

Overall Contributors

PersonTokensPropCommitsCommitProp
kumar galakumar gala37636.08%13.70%
uwe kleine-koeniguwe kleine-koenig27826.68%622.22%
anton vorontsovanton vorontsov26925.82%518.52%
christophe leroychristophe leroy706.72%27.41%
grant likelygrant likely272.59%414.81%
joe perchesjoe perches90.86%13.70%
wim van sebroeckwim van sebroeck30.29%27.41%
rob herringrob herring30.29%13.70%
alan coxalan cox20.19%13.70%
kay sieverskay sievers20.19%13.70%
arnd bergmannarnd bergmann10.10%13.70%
rusty russellrusty russell10.10%13.70%
randy dunlaprandy dunlap10.10%13.70%
Total1042100.00%27100.00%
Directory: drivers/watchdog
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