watchdog: Remove BCM63XX_WDT

Now that we can utilize the BCM7038_WDT driver, remove that one which
was not converted to the watchdog APIs. There are a couple of notable
differences with how the bcm7038_wdt driver proceeds:

- bcm63xx_wdt would register with the ad-hoc BCM63xx hardware timer API,
  but this would only be used in order to catch the interrupt *before* a
  SoC reset and make the kernel "die"

- bcm6xx_wdt would register a software timer and kick it every second in
  order to pet the watchdog, thus offering a two step watchdog process.
  This is not something that is brought over to the bcm7038_wdt as it is
  deemed unnecessary. If user-space cannot pet the watchdog, but a
  kernel timer can, the system is still in a bad shape anyway.

bcm7038_wdt is simpler in its behavior and behaves as a standard
watchdog driver and is not making use of any specific platform APIs,
therefore making it more maintainable and extensible.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20211112224636.395101-8-f.fainelli@gmail.comSigned-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

drivers/watchdog/Kconfig

@@ -1697,16 +1697,6 @@ config OCTEON_WDT
 	  from the first interrupt, it is then only poked when the
 	  device is written.
 
-config BCM63XX_WDT
-	tristate "Broadcom BCM63xx hardware watchdog"
-	depends on BCM63XX
-	help
-	  Watchdog driver for the built in watchdog hardware in Broadcom
-	  BCM63xx SoC.
-
-	  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 || (OF && COMPILE_TEST)

drivers/watchdog/Makefile

@@ -153,7 +153,6 @@ obj-$(CONFIG_XILINX_WATCHDOG) += of_xilinx_wdt.o
 # MIPS Architecture
 obj-$(CONFIG_ATH79_WDT) += ath79_wdt.o
 obj-$(CONFIG_BCM47XX_WDT) += bcm47xx_wdt.o
-obj-$(CONFIG_BCM63XX_WDT) += bcm63xx_wdt.o
 obj-$(CONFIG_RC32434_WDT) += rc32434_wdt.o
 obj-$(CONFIG_INDYDOG) += indydog.o
 obj-$(CONFIG_JZ4740_WDT) += jz4740_wdt.o

drivers/watchdog/bcm63xx_wdt.c

-// 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();
-
-		fallthrough;
-
-	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,
-	.compat_ioctl	= compat_ptr_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(&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");