drivers/watchdog/bcm63xx_wdt.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 /*
  *  Broadcom BCM63xx SoC watchdog driver
  *
  *  Copyright (C) 2007, Miguel Gaio <miguel.gaio@efixo.com>
  *  Copyright (C) 2008, Florian Fainelli <florian@openwrt.org>
  *
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <linux/bitops.h>
 #include <linux/errno.h>
 #include <linux/fs.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/types.h>
 #include <linux/uaccess.h>
 #include <linux/watchdog.h>
 #include <linux/timer.h>
 #include <linux/jiffies.h>
 #include <linux/interrupt.h>
 #include <linux/ptrace.h>
 #include <linux/resource.h>
 #include <linux/platform_device.h>

 #include <bcm63xx_cpu.h>
 #include <bcm63xx_io.h>
 #include <bcm63xx_regs.h>
 #include <bcm63xx_timer.h>

 #define PFX KBUILD_MODNAME

 #define WDT_HZ		50000000 /* Fclk */
 #define WDT_DEFAULT_TIME	30      /* seconds */
 #define WDT_MAX_TIME		256     /* seconds */

 static struct {
 	void __iomem *regs;
 	struct timer_list timer;
 	unsigned long inuse;
 	atomic_t ticks;
 } bcm63xx_wdt_device;

 static int expect_close;

 static int wdt_time = WDT_DEFAULT_TIME;
 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) ")");

 /* HW functions */
 static void bcm63xx_wdt_hw_start(void)
 {
 	bcm_writel(0xfffffffe, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG);
 	bcm_writel(WDT_START_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
 	bcm_writel(WDT_START_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
 }

 static void bcm63xx_wdt_hw_stop(void)
 {
 	bcm_writel(WDT_STOP_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
 	bcm_writel(WDT_STOP_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
 }

 static void bcm63xx_wdt_isr(void *data)
 {
 	struct pt_regs *regs = get_irq_regs();

 	die(PFX " fire", regs);
 }

 static void bcm63xx_timer_tick(struct timer_list *unused)
 {
 	if (!atomic_dec_and_test(&bcm63xx_wdt_device.ticks)) {
 		bcm63xx_wdt_hw_start();
 		mod_timer(&bcm63xx_wdt_device.timer, jiffies + HZ);
 	} else
 		pr_crit("watchdog will restart system\n");
 }

 static void bcm63xx_wdt_pet(void)
 {
 	atomic_set(&bcm63xx_wdt_device.ticks, wdt_time);
 }

 static void bcm63xx_wdt_start(void)
 {
 	bcm63xx_wdt_pet();
 	bcm63xx_timer_tick(0);
 }

 static void bcm63xx_wdt_pause(void)
 {
 	del_timer_sync(&bcm63xx_wdt_device.timer);
 	bcm63xx_wdt_hw_stop();
 }

 static int bcm63xx_wdt_settimeout(int new_time)
 {
 	if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
 		return -EINVAL;

 	wdt_time = new_time;

 	return 0;
 }

 static int bcm63xx_wdt_open(struct inode *inode, struct file *file)
 {
 	if (test_and_set_bit(0, &bcm63xx_wdt_device.inuse))
 		return -EBUSY;

 	bcm63xx_wdt_start();
 	return stream_open(inode, file);
 }

 static int bcm63xx_wdt_release(struct inode *inode, struct file *file)
 {
 	if (expect_close == 42)
 		bcm63xx_wdt_pause();
 	else {
 		pr_crit("Unexpected close, not stopping watchdog!\n");
 		bcm63xx_wdt_start();
 	}
 	clear_bit(0, &bcm63xx_wdt_device.inuse);
 	expect_close = 0;
 	return 0;
 }

 static ssize_t bcm63xx_wdt_write(struct file *file, const char *data,
 				size_t len, loff_t *ppos)
 {
 	if (len) {
 		if (!nowayout) {
 			size_t i;

 			/* In case it was set long ago */
 			expect_close = 0;

 			for (i = 0; i != len; i++) {
 				char c;
 				if (get_user(c, data + i))
 					return -EFAULT;
 				if (c == 'V')
 					expect_close = 42;
 			}
 		}
 		bcm63xx_wdt_pet();
 	}
 	return len;
 }

 static struct watchdog_info bcm63xx_wdt_info = {
 	.identity       = PFX,
 	.options        = WDIOF_SETTIMEOUT |
 				WDIOF_KEEPALIVEPING |
 				WDIOF_MAGICCLOSE,
 };


 static long bcm63xx_wdt_ioctl(struct file *file, unsigned int cmd,
 				unsigned long arg)
 {
 	void __user *argp = (void __user *)arg;
 	int __user *p = argp;
 	int new_value, retval = -EINVAL;

 	switch (cmd) {
 	case WDIOC_GETSUPPORT:
 		return copy_to_user(argp, &bcm63xx_wdt_info,
 			sizeof(bcm63xx_wdt_info)) ? -EFAULT : 0;

 	case WDIOC_GETSTATUS:
 	case WDIOC_GETBOOTSTATUS:
 		return put_user(0, p);

 	case WDIOC_SETOPTIONS:
 		if (get_user(new_value, p))
 			return -EFAULT;

 		if (new_value & WDIOS_DISABLECARD) {
 			bcm63xx_wdt_pause();
 			retval = 0;
 		}
 		if (new_value & WDIOS_ENABLECARD) {
 			bcm63xx_wdt_start();
 			retval = 0;
 		}

 		return retval;

 	case WDIOC_KEEPALIVE:
 		bcm63xx_wdt_pet();
 		return 0;

 	case WDIOC_SETTIMEOUT:
 		if (get_user(new_value, p))
 			return -EFAULT;

 		if (bcm63xx_wdt_settimeout(new_value))
 			return -EINVAL;

 		bcm63xx_wdt_pet();

 	case WDIOC_GETTIMEOUT:
 		return put_user(wdt_time, p);

 	default:
 		return -ENOTTY;

 	}
 }

 static const struct file_operations bcm63xx_wdt_fops = {
 	.owner		= THIS_MODULE,
 	.llseek		= no_llseek,
 	.write		= bcm63xx_wdt_write,
 	.unlocked_ioctl	= bcm63xx_wdt_ioctl,
 	.open		= bcm63xx_wdt_open,
 	.release	= bcm63xx_wdt_release,
 };

 static struct miscdevice bcm63xx_wdt_miscdev = {
 	.minor	= WATCHDOG_MINOR,
 	.name	= "watchdog",
 	.fops	= &bcm63xx_wdt_fops,
 };


 static int bcm63xx_wdt_probe(struct platform_device *pdev)
 {
 	int ret;
 	struct resource *r;

 	timer_setup(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0);

 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!r) {
 		dev_err(&pdev->dev, "failed to get resources\n");
 		return -ENODEV;
 	}

 	bcm63xx_wdt_device.regs = devm_ioremap_nocache(&pdev->dev, r->start,
 							resource_size(r));
 	if (!bcm63xx_wdt_device.regs) {
 		dev_err(&pdev->dev, "failed to remap I/O resources\n");
 		return -ENXIO;
 	}

 	ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, NULL);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed to register wdt timer isr\n");
 		return ret;
 	}

 	if (bcm63xx_wdt_settimeout(wdt_time)) {
 		bcm63xx_wdt_settimeout(WDT_DEFAULT_TIME);
 		dev_info(&pdev->dev,
 			": wdt_time value must be 1 <= wdt_time <= 256, using %d\n",
 			wdt_time);
 	}

 	ret = misc_register(&bcm63xx_wdt_miscdev);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed to register watchdog device\n");
 		goto unregister_timer;
 	}

 	dev_info(&pdev->dev, " started, timer margin: %d sec\n",
 						WDT_DEFAULT_TIME);

 	return 0;

 unregister_timer:
 	bcm63xx_timer_unregister(TIMER_WDT_ID);
 	return ret;
 }

 static int bcm63xx_wdt_remove(struct platform_device *pdev)
 {
 	if (!nowayout)
 		bcm63xx_wdt_pause();

 	misc_deregister(&bcm63xx_wdt_miscdev);
 	bcm63xx_timer_unregister(TIMER_WDT_ID);
 	return 0;
 }

 static void bcm63xx_wdt_shutdown(struct platform_device *pdev)
 {
 	bcm63xx_wdt_pause();
 }

 static struct platform_driver bcm63xx_wdt_driver = {
 	.probe	= bcm63xx_wdt_probe,
 	.remove = bcm63xx_wdt_remove,
 	.shutdown = bcm63xx_wdt_shutdown,
 	.driver = {
 		.name = "bcm63xx-wdt",
 	}
 };

 module_platform_driver(bcm63xx_wdt_driver);

 MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>");
 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
 MODULE_DESCRIPTION("Driver for the Broadcom BCM63xx SoC watchdog");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:bcm63xx-wdt");
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* Broadcom BCM63xx SoC watchdog driver
	*
	* Copyright (C) 2007, Miguel Gaio <miguel.gaio@efixo.com>
	* Copyright (C) 2008, Florian Fainelli <florian@openwrt.org>
	*
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/bitops.h>
	#include <linux/errno.h>
	#include <linux/fs.h>
	#include <linux/io.h>
	#include <linux/kernel.h>
	#include <linux/miscdevice.h>
	#include <linux/module.h>
	#include <linux/moduleparam.h>
	#include <linux/types.h>
	#include <linux/uaccess.h>
	#include <linux/watchdog.h>
	#include <linux/timer.h>
	#include <linux/jiffies.h>
	#include <linux/interrupt.h>
	#include <linux/ptrace.h>
	#include <linux/resource.h>
	#include <linux/platform_device.h>

	#include <bcm63xx_cpu.h>
	#include <bcm63xx_io.h>
	#include <bcm63xx_regs.h>
	#include <bcm63xx_timer.h>

	#define PFX KBUILD_MODNAME

	#define WDT_HZ 50000000 /* Fclk */
	#define WDT_DEFAULT_TIME 30 /* seconds */
	#define WDT_MAX_TIME 256 /* seconds */

	static struct {
	void __iomem *regs;
	struct timer_list timer;
	unsigned long inuse;
	atomic_t ticks;
	} bcm63xx_wdt_device;

	static int expect_close;

	static int wdt_time = WDT_DEFAULT_TIME;
	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) ")");

	/* HW functions */
	static void bcm63xx_wdt_hw_start(void)
	{
	bcm_writel(0xfffffffe, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG);
	bcm_writel(WDT_START_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
	bcm_writel(WDT_START_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
	}

	static void bcm63xx_wdt_hw_stop(void)
	{
	bcm_writel(WDT_STOP_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
	bcm_writel(WDT_STOP_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
	}

	static void bcm63xx_wdt_isr(void *data)
	{
	struct pt_regs *regs = get_irq_regs();

	die(PFX " fire", regs);
	}

	static void bcm63xx_timer_tick(struct timer_list *unused)
	{
	if (!atomic_dec_and_test(&bcm63xx_wdt_device.ticks)) {
	bcm63xx_wdt_hw_start();
	mod_timer(&bcm63xx_wdt_device.timer, jiffies + HZ);
	} else
	pr_crit("watchdog will restart system\n");
	}

	static void bcm63xx_wdt_pet(void)
	{
	atomic_set(&bcm63xx_wdt_device.ticks, wdt_time);
	}

	static void bcm63xx_wdt_start(void)
	{
	bcm63xx_wdt_pet();
	bcm63xx_timer_tick(0);
	}

	static void bcm63xx_wdt_pause(void)
	{
	del_timer_sync(&bcm63xx_wdt_device.timer);
	bcm63xx_wdt_hw_stop();
	}

	static int bcm63xx_wdt_settimeout(int new_time)
	{
	if ((new_time <= 0) \|\| (new_time > WDT_MAX_TIME))
	return -EINVAL;

	wdt_time = new_time;

	return 0;
	}

	static int bcm63xx_wdt_open(struct inode inode, struct file file)
	{
	if (test_and_set_bit(0, &bcm63xx_wdt_device.inuse))
	return -EBUSY;

	bcm63xx_wdt_start();
	return stream_open(inode, file);
	}

	static int bcm63xx_wdt_release(struct inode inode, struct file file)
	{
	if (expect_close == 42)
	bcm63xx_wdt_pause();
	else {
	pr_crit("Unexpected close, not stopping watchdog!\n");
	bcm63xx_wdt_start();
	}
	clear_bit(0, &bcm63xx_wdt_device.inuse);
	expect_close = 0;
	return 0;
	}

	static ssize_t bcm63xx_wdt_write(struct file file, const char data,
	size_t len, loff_t *ppos)
	{
	if (len) {
	if (!nowayout) {
	size_t i;

	/* In case it was set long ago */
	expect_close = 0;

	for (i = 0; i != len; i++) {
	char c;
	if (get_user(c, data + i))
	return -EFAULT;
	if (c == 'V')
	expect_close = 42;
	}
	}
	bcm63xx_wdt_pet();
	}
	return len;
	}

	static struct watchdog_info bcm63xx_wdt_info = {
	.identity = PFX,
	.options = WDIOF_SETTIMEOUT \|
	WDIOF_KEEPALIVEPING \|
	WDIOF_MAGICCLOSE,
	};


	static long bcm63xx_wdt_ioctl(struct file *file, unsigned int cmd,
	unsigned long arg)
	{
	void __user argp = (void __user )arg;
	int __user *p = argp;
	int new_value, retval = -EINVAL;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
	return copy_to_user(argp, &bcm63xx_wdt_info,
	sizeof(bcm63xx_wdt_info)) ? -EFAULT : 0;

	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
	return put_user(0, p);

	case WDIOC_SETOPTIONS:
	if (get_user(new_value, p))
	return -EFAULT;

	if (new_value & WDIOS_DISABLECARD) {
	bcm63xx_wdt_pause();
	retval = 0;
	}
	if (new_value & WDIOS_ENABLECARD) {
	bcm63xx_wdt_start();
	retval = 0;
	}

	return retval;

	case WDIOC_KEEPALIVE:
	bcm63xx_wdt_pet();
	return 0;

	case WDIOC_SETTIMEOUT:
	if (get_user(new_value, p))
	return -EFAULT;

	if (bcm63xx_wdt_settimeout(new_value))
	return -EINVAL;

	bcm63xx_wdt_pet();

	case WDIOC_GETTIMEOUT:
	return put_user(wdt_time, p);

	default:
	return -ENOTTY;

	}
	}

	static const struct file_operations bcm63xx_wdt_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.write = bcm63xx_wdt_write,
	.unlocked_ioctl = bcm63xx_wdt_ioctl,
	.open = bcm63xx_wdt_open,
	.release = bcm63xx_wdt_release,
	};

	static struct miscdevice bcm63xx_wdt_miscdev = {
	.minor = WATCHDOG_MINOR,
	.name = "watchdog",
	.fops = &bcm63xx_wdt_fops,
	};


	static int bcm63xx_wdt_probe(struct platform_device *pdev)
	{
	int ret;
	struct resource *r;

	timer_setup(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0);

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!r) {
	dev_err(&pdev->dev, "failed to get resources\n");
	return -ENODEV;
	}

	bcm63xx_wdt_device.regs = devm_ioremap_nocache(&pdev->dev, r->start,
	resource_size(r));
	if (!bcm63xx_wdt_device.regs) {
	dev_err(&pdev->dev, "failed to remap I/O resources\n");
	return -ENXIO;
	}

	ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, NULL);
	if (ret < 0) {
	dev_err(&pdev->dev, "failed to register wdt timer isr\n");
	return ret;
	}

	if (bcm63xx_wdt_settimeout(wdt_time)) {
	bcm63xx_wdt_settimeout(WDT_DEFAULT_TIME);
	dev_info(&pdev->dev,
	": wdt_time value must be 1 <= wdt_time <= 256, using %d\n",
	wdt_time);
	}

	ret = misc_register(&bcm63xx_wdt_miscdev);
	if (ret < 0) {
	dev_err(&pdev->dev, "failed to register watchdog device\n");
	goto unregister_timer;
	}

	dev_info(&pdev->dev, " started, timer margin: %d sec\n",
	WDT_DEFAULT_TIME);

	return 0;

	unregister_timer:
	bcm63xx_timer_unregister(TIMER_WDT_ID);
	return ret;
	}

	static int bcm63xx_wdt_remove(struct platform_device *pdev)
	{
	if (!nowayout)
	bcm63xx_wdt_pause();

	misc_deregister(&bcm63xx_wdt_miscdev);
	bcm63xx_timer_unregister(TIMER_WDT_ID);
	return 0;
	}

	static void bcm63xx_wdt_shutdown(struct platform_device *pdev)
	{
	bcm63xx_wdt_pause();
	}

	static struct platform_driver bcm63xx_wdt_driver = {
	.probe = bcm63xx_wdt_probe,
	.remove = bcm63xx_wdt_remove,
	.shutdown = bcm63xx_wdt_shutdown,
	.driver = {
	.name = "bcm63xx-wdt",
	}
	};

	module_platform_driver(bcm63xx_wdt_driver);

	MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>");
	MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
	MODULE_DESCRIPTION("Driver for the Broadcom BCM63xx SoC watchdog");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:bcm63xx-wdt");