Commit 1bc6e013 authored by Wolfram Sang's avatar Wolfram Sang Committed by Thomas Bogendoerfer
Browse files

watchdog: ar7_wdt: remove driver to prepare for platform removal 



AR7 is going to be removed from the Kernel, so remove its watchdog
support. This allows us to remove the platform because this driver
includes a platform specific header.

Signed-off-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Acked-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarThomas Bogendoerfer <tsbogend@alpha.franken.de>
parent 9a6c7821

drivers/watchdog/Kconfig

+0 −6
Original line number Diff line number Diff line
@@ -1768,12 +1768,6 @@ config SIBYTE_WDOG 
	  To compile this driver as a loadable module, choose M here.

	  The module will be called sb_wdog.



config AR7_WDT

	tristate "TI AR7 Watchdog Timer"

	depends on AR7 || (MIPS && 32BIT && COMPILE_TEST)

	help

	  Hardware driver for the TI AR7 Watchdog Timer.



config TXX9_WDT

	tristate "Toshiba TXx9 Watchdog Timer"

	depends on CPU_TX49XX || (MIPS && COMPILE_TEST)

drivers/watchdog/Makefile

+0 −1
Original line number Diff line number Diff line
@@ -168,7 +168,6 @@ obj-$(CONFIG_INDYDOG) += indydog.o 
obj-$(CONFIG_JZ4740_WDT) += jz4740_wdt.o

obj-$(CONFIG_WDT_MTX1) += mtx-1_wdt.o

obj-$(CONFIG_SIBYTE_WDOG) += sb_wdog.o

obj-$(CONFIG_AR7_WDT) += ar7_wdt.o

obj-$(CONFIG_TXX9_WDT) += txx9wdt.o

obj-$(CONFIG_OCTEON_WDT) += octeon-wdt.o

octeon-wdt-y := octeon-wdt-main.o octeon-wdt-nmi.o

drivers/watchdog/ar7_wdt.c

deleted100644 → 0
+0 −315
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0+

/*

 * drivers/watchdog/ar7_wdt.c

 *

 * Copyright (C) 2007 Nicolas Thill <nico@openwrt.org>

 * Copyright (c) 2005 Enrik Berkhan <Enrik.Berkhan@akk.org>

 *

 * Some code taken from:

 * National Semiconductor SCx200 Watchdog support

 * Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>

 *

 */



#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt



#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/errno.h>

#include <linux/miscdevice.h>

#include <linux/platform_device.h>

#include <linux/watchdog.h>

#include <linux/fs.h>

#include <linux/ioport.h>

#include <linux/io.h>

#include <linux/uaccess.h>

#include <linux/clk.h>



#include <asm/addrspace.h>

#include <asm/mach-ar7/ar7.h>



#define LONGNAME "TI AR7 Watchdog Timer"



MODULE_AUTHOR("Nicolas Thill <nico@openwrt.org>");

MODULE_DESCRIPTION(LONGNAME);

MODULE_LICENSE("GPL");



static int margin = 60;

module_param(margin, int, 0);

MODULE_PARM_DESC(margin, "Watchdog margin in seconds");



static bool nowayout = WATCHDOG_NOWAYOUT;

module_param(nowayout, bool, 0);

MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");



#define READ_REG(x) readl((void __iomem *)&(x))

#define WRITE_REG(x, v) writel((v), (void __iomem *)&(x))



struct ar7_wdt {

	u32 kick_lock;

	u32 kick;

	u32 change_lock;

	u32 change;

	u32 disable_lock;

	u32 disable;

	u32 prescale_lock;

	u32 prescale;

};



static unsigned long wdt_is_open;

static unsigned expect_close;

static DEFINE_SPINLOCK(wdt_lock);



/* XXX currently fixed, allows max margin ~68.72 secs */

#define prescale_value 0xffff



/* Pointer to the remapped WDT IO space */

static struct ar7_wdt *ar7_wdt;



static struct clk *vbus_clk;



static void ar7_wdt_kick(u32 value)

{

	WRITE_REG(ar7_wdt->kick_lock, 0x5555);

	if ((READ_REG(ar7_wdt->kick_lock) & 3) == 1) {

		WRITE_REG(ar7_wdt->kick_lock, 0xaaaa);

		if ((READ_REG(ar7_wdt->kick_lock) & 3) == 3) {

			WRITE_REG(ar7_wdt->kick, value);

			return;

		}

	}

	pr_err("failed to unlock WDT kick reg\n");

}



static void ar7_wdt_prescale(u32 value)

{

	WRITE_REG(ar7_wdt->prescale_lock, 0x5a5a);

	if ((READ_REG(ar7_wdt->prescale_lock) & 3) == 1) {

		WRITE_REG(ar7_wdt->prescale_lock, 0xa5a5);

		if ((READ_REG(ar7_wdt->prescale_lock) & 3) == 3) {

			WRITE_REG(ar7_wdt->prescale, value);

			return;

		}

	}

	pr_err("failed to unlock WDT prescale reg\n");

}



static void ar7_wdt_change(u32 value)

{

	WRITE_REG(ar7_wdt->change_lock, 0x6666);

	if ((READ_REG(ar7_wdt->change_lock) & 3) == 1) {

		WRITE_REG(ar7_wdt->change_lock, 0xbbbb);

		if ((READ_REG(ar7_wdt->change_lock) & 3) == 3) {

			WRITE_REG(ar7_wdt->change, value);

			return;

		}

	}

	pr_err("failed to unlock WDT change reg\n");

}



static void ar7_wdt_disable(u32 value)

{

	WRITE_REG(ar7_wdt->disable_lock, 0x7777);

	if ((READ_REG(ar7_wdt->disable_lock) & 3) == 1) {

		WRITE_REG(ar7_wdt->disable_lock, 0xcccc);

		if ((READ_REG(ar7_wdt->disable_lock) & 3) == 2) {

			WRITE_REG(ar7_wdt->disable_lock, 0xdddd);

			if ((READ_REG(ar7_wdt->disable_lock) & 3) == 3) {

				WRITE_REG(ar7_wdt->disable, value);

				return;

			}

		}

	}

	pr_err("failed to unlock WDT disable reg\n");

}



static void ar7_wdt_update_margin(int new_margin)

{

	u32 change;

	u32 vbus_rate;



	vbus_rate = clk_get_rate(vbus_clk);

	change = new_margin * (vbus_rate / prescale_value);

	if (change < 1)

		change = 1;

	if (change > 0xffff)

		change = 0xffff;

	ar7_wdt_change(change);

	margin = change * prescale_value / vbus_rate;

	pr_info("timer margin %d seconds (prescale %d, change %d, freq %d)\n",

		margin, prescale_value, change, vbus_rate);

}



static void ar7_wdt_enable_wdt(void)

{

	pr_debug("enabling watchdog timer\n");

	ar7_wdt_disable(1);

	ar7_wdt_kick(1);

}



static void ar7_wdt_disable_wdt(void)

{

	pr_debug("disabling watchdog timer\n");

	ar7_wdt_disable(0);

}



static int ar7_wdt_open(struct inode *inode, struct file *file)

{

	/* only allow one at a time */

	if (test_and_set_bit(0, &wdt_is_open))

		return -EBUSY;

	ar7_wdt_enable_wdt();

	expect_close = 0;



	return stream_open(inode, file);

}



static int ar7_wdt_release(struct inode *inode, struct file *file)

{

	if (!expect_close)

		pr_warn("watchdog device closed unexpectedly, will not disable the watchdog timer\n");

	else if (!nowayout)

		ar7_wdt_disable_wdt();

	clear_bit(0, &wdt_is_open);

	return 0;

}



static ssize_t ar7_wdt_write(struct file *file, const char *data,

			     size_t len, loff_t *ppos)

{

	/* check for a magic close character */

	if (len) {

		size_t i;



		spin_lock(&wdt_lock);

		ar7_wdt_kick(1);

		spin_unlock(&wdt_lock);



		expect_close = 0;

		for (i = 0; i < len; ++i) {

			char c;

			if (get_user(c, data + i))

				return -EFAULT;

			if (c == 'V')

				expect_close = 1;

		}



	}

	return len;

}



static long ar7_wdt_ioctl(struct file *file,

					unsigned int cmd, unsigned long arg)

{

	static const struct watchdog_info ident = {

		.identity = LONGNAME,

		.firmware_version = 1,

		.options = (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |

						WDIOF_MAGICCLOSE),

	};

	int new_margin;



	switch (cmd) {

	case WDIOC_GETSUPPORT:

		if (copy_to_user((struct watchdog_info *)arg, &ident,

				sizeof(ident)))

			return -EFAULT;

		return 0;

	case WDIOC_GETSTATUS:

	case WDIOC_GETBOOTSTATUS:

		if (put_user(0, (int *)arg))

			return -EFAULT;

		return 0;

	case WDIOC_KEEPALIVE:

		ar7_wdt_kick(1);

		return 0;

	case WDIOC_SETTIMEOUT:

		if (get_user(new_margin, (int *)arg))

			return -EFAULT;

		if (new_margin < 1)

			return -EINVAL;



		spin_lock(&wdt_lock);

		ar7_wdt_update_margin(new_margin);

		ar7_wdt_kick(1);

		spin_unlock(&wdt_lock);

		fallthrough;

	case WDIOC_GETTIMEOUT:

		if (put_user(margin, (int *)arg))

			return -EFAULT;

		return 0;

	default:

		return -ENOTTY;

	}

}



static const struct file_operations ar7_wdt_fops = {

	.owner		= THIS_MODULE,

	.write		= ar7_wdt_write,

	.unlocked_ioctl	= ar7_wdt_ioctl,

	.compat_ioctl	= compat_ptr_ioctl,

	.open		= ar7_wdt_open,

	.release	= ar7_wdt_release,

	.llseek		= no_llseek,

};



static struct miscdevice ar7_wdt_miscdev = {

	.minor		= WATCHDOG_MINOR,

	.name		= "watchdog",

	.fops		= &ar7_wdt_fops,

};



static int ar7_wdt_probe(struct platform_device *pdev)

{

	int rc;



	ar7_wdt = devm_platform_ioremap_resource_byname(pdev, "regs");

	if (IS_ERR(ar7_wdt))

		return PTR_ERR(ar7_wdt);



	vbus_clk = clk_get(NULL, "vbus");

	if (IS_ERR(vbus_clk)) {

		pr_err("could not get vbus clock\n");

		return PTR_ERR(vbus_clk);

	}



	ar7_wdt_disable_wdt();

	ar7_wdt_prescale(prescale_value);

	ar7_wdt_update_margin(margin);



	rc = misc_register(&ar7_wdt_miscdev);

	if (rc) {

		pr_err("unable to register misc device\n");

		goto out;

	}

	return 0;



out:

	clk_put(vbus_clk);

	vbus_clk = NULL;

	return rc;

}



static void ar7_wdt_remove(struct platform_device *pdev)

{

	misc_deregister(&ar7_wdt_miscdev);

	clk_put(vbus_clk);

	vbus_clk = NULL;

}



static void ar7_wdt_shutdown(struct platform_device *pdev)

{

	if (!nowayout)

		ar7_wdt_disable_wdt();

}



static struct platform_driver ar7_wdt_driver = {

	.probe = ar7_wdt_probe,

	.remove_new = ar7_wdt_remove,

	.shutdown = ar7_wdt_shutdown,

	.driver = {

		.name = "ar7_wdt",

	},

};



module_platform_driver(ar7_wdt_driver);