kernel: add generic GPIO watchdog driver

This is used on Huawei E970 (brcm47xx).

Signed-off-by: Mathias Adam <m.adam--openwrt@adamis.de>


git-svn-id: svn://svn.openwrt.org/openwrt/trunk@38010 3c298f89-4303-0410-b956-a3cf2f4a3e73

2 files changed, 361 insertions, 0 deletions

diff --git a/target/linux/generic/config-3.10 b/target/linux/generic/config-3.10
index 0f3b78f2a7..46ac8c0285 100644
--- a/target/linux/generic/config-3.10
+++ b/target/linux/generic/config-3.10
@@ -1000,6 +1000,7 @@ CONFIG_GENERIC_TIME=y
 # CONFIG_GPIO_SYSFS is not set
 # CONFIG_GPIO_TS5500 is not set
 # CONFIG_GPIO_VX855 is not set
+# CONFIG_GPIO_WDT is not set
 # CONFIG_GPIO_XILINX is not set
 # CONFIG_GREENASIA_FF is not set
 # CONFIG_HAMACHI is not set
diff --git a/target/linux/generic/patches-3.10/990-gpio_wdt.patch b/target/linux/generic/patches-3.10/990-gpio_wdt.patch
new file mode 100644
index 0000000000..4e77cb65a9
--- /dev/null
+++ b/target/linux/generic/patches-3.10/990-gpio_wdt.patch
@@ -0,0 +1,360 @@
+This generic GPIO watchdog is used on Huawei E970 (brcm47xx)
+
+Signed-off-by: Mathias Adam <m.adam--openwrt@adamis.de>
+
+--- a/drivers/watchdog/Kconfig
++++ b/drivers/watchdog/Kconfig
+@@ -1035,6 +1035,15 @@ config WDT_MTX1
+ 	  Hardware driver for the MTX-1 boards. This is a watchdog timer that
+ 	  will reboot the machine after a 100 seconds timer expired.
+ 
++config GPIO_WDT
++	tristate "GPIO Hardware Watchdog"
++ 	help
++	  Hardware driver for GPIO-controlled watchdogs. GPIO pin and
++	  toggle interval settings are platform-specific. The driver
++	  will stop toggling the GPIO (i.e. machine reboots) after a
++	  100 second timer expired and no process has written to
++	  /dev/watchdog during that time.
++
+ config PNX833X_WDT
+ 	tristate "PNX833x Hardware Watchdog"
+ 	depends on SOC_PNX8335
+--- a/drivers/watchdog/Makefile
++++ b/drivers/watchdog/Makefile
+@@ -127,6 +127,7 @@ obj-$(CONFIG_RC32434_WDT) += rc32434_wdt
+ obj-$(CONFIG_INDYDOG) += indydog.o
+ obj-$(CONFIG_JZ4740_WDT) += jz4740_wdt.o
+ obj-$(CONFIG_WDT_MTX1) += mtx-1_wdt.o
++obj-$(CONFIG_GPIO_WDT) += gpio_wdt.o
+ obj-$(CONFIG_PNX833X_WDT) += pnx833x_wdt.o
+ obj-$(CONFIG_SIBYTE_WDOG) += sb_wdog.o
+ obj-$(CONFIG_AR7_WDT) += ar7_wdt.o
+--- /dev/null
++++ b/drivers/watchdog/gpio_wdt.c
+@@ -0,0 +1,301 @@
++/*
++ *      Driver for GPIO-controlled Hardware Watchdogs.
++ *
++ *      Copyright (C) 2013 Mathias Adam <m.adam--linux@adamis.de>
++ *
++ *      Replaces mtx1_wdt (driver for the MTX-1 Watchdog):
++ *
++ *      (C) Copyright 2005 4G Systems <info@4g-systems.biz>,
++ *                              All Rights Reserved.
++ *                              http://www.4g-systems.biz
++ *
++ *      (C) Copyright 2007 OpenWrt.org, Florian Fainelli <florian@openwrt.org>
++ *
++ *      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.
++ *
++ *      Neither Michael Stickel nor 4G Systems admit liability nor provide
++ *      warranty for any of this software. This material is provided
++ *      "AS-IS" and at no charge.
++ *
++ *      (c) Copyright 2005    4G Systems <info@4g-systems.biz>
++ *
++ *      Release 0.01.
++ *      Author: Michael Stickel  michael.stickel@4g-systems.biz
++ *
++ *      Release 0.02.
++ *      Author: Florian Fainelli florian@openwrt.org
++ *              use the Linux watchdog/timer APIs
++ *
++ *      Release 0.03.
++ *      Author: Mathias Adam <m.adam--linux@adamis.de>
++ *              make it a generic gpio watchdog driver
++ *
++ *      The Watchdog is configured to reset the MTX-1
++ *      if it is not triggered for 100 seconds.
++ *      It should not be triggered more often than 1.6 seconds.
++ *
++ *      A timer triggers the watchdog every 5 seconds, until
++ *      it is opened for the first time. After the first open
++ *      it MUST be triggered every 2..95 seconds.
++ */
++
++#include <linux/module.h>
++#include <linux/moduleparam.h>
++#include <linux/types.h>
++#include <linux/errno.h>
++#include <linux/miscdevice.h>
++#include <linux/fs.h>
++#include <linux/init.h>
++#include <linux/ioport.h>
++#include <linux/timer.h>
++#include <linux/completion.h>
++#include <linux/jiffies.h>
++#include <linux/watchdog.h>
++#include <linux/platform_device.h>
++#include <linux/io.h>
++#include <linux/uaccess.h>
++#include <linux/gpio.h>
++#include <linux/gpio_wdt.h>
++
++static int ticks = 100 * HZ;
++
++static struct {
++	struct completion stop;
++	spinlock_t lock;
++	int running;
++	struct timer_list timer;
++	int queue;
++	int default_ticks;
++	unsigned long inuse;
++	unsigned gpio;
++	unsigned int gstate;
++	int interval;
++	int first_interval;
++} gpio_wdt_device;
++
++static void gpio_wdt_trigger(unsigned long unused)
++{
++	spin_lock(&gpio_wdt_device.lock);
++	if (gpio_wdt_device.running && ticks > 0)
++		ticks -= gpio_wdt_device.interval;
++
++	/* toggle wdt gpio */
++	gpio_wdt_device.gstate = !gpio_wdt_device.gstate;
++	gpio_set_value(gpio_wdt_device.gpio, gpio_wdt_device.gstate);
++
++	if (gpio_wdt_device.queue && ticks > 0)
++		mod_timer(&gpio_wdt_device.timer, jiffies + gpio_wdt_device.interval);
++	else
++		complete(&gpio_wdt_device.stop);
++	spin_unlock(&gpio_wdt_device.lock);
++}
++
++static void gpio_wdt_reset(void)
++{
++	ticks = gpio_wdt_device.default_ticks;
++}
++
++
++static void gpio_wdt_start(void)
++{
++	unsigned long flags;
++
++	spin_lock_irqsave(&gpio_wdt_device.lock, flags);
++	if (!gpio_wdt_device.queue) {
++		gpio_wdt_device.queue = 1;
++		gpio_wdt_device.gstate = 1;
++		gpio_set_value(gpio_wdt_device.gpio, 1);
++		mod_timer(&gpio_wdt_device.timer, jiffies + gpio_wdt_device.first_interval);
++	}
++	gpio_wdt_device.running++;
++	spin_unlock_irqrestore(&gpio_wdt_device.lock, flags);
++}
++
++static int gpio_wdt_stop(void)
++{
++	unsigned long flags;
++
++	spin_lock_irqsave(&gpio_wdt_device.lock, flags);
++	if (gpio_wdt_device.queue) {
++		gpio_wdt_device.queue = 0;
++		gpio_wdt_device.gstate = 0;
++		gpio_set_value(gpio_wdt_device.gpio, 0);
++	}
++	ticks = gpio_wdt_device.default_ticks;
++	spin_unlock_irqrestore(&gpio_wdt_device.lock, flags);
++	return 0;
++}
++
++/* Filesystem functions */
++
++static int gpio_wdt_open(struct inode *inode, struct file *file)
++{
++	if (test_and_set_bit(0, &gpio_wdt_device.inuse))
++		return -EBUSY;
++	return nonseekable_open(inode, file);
++}
++
++
++static int gpio_wdt_release(struct inode *inode, struct file *file)
++{
++	clear_bit(0, &gpio_wdt_device.inuse);
++	return 0;
++}
++
++static long gpio_wdt_ioctl(struct file *file, unsigned int cmd,
++							unsigned long arg)
++{
++	void __user *argp = (void __user *)arg;
++	int __user *p = (int __user *)argp;
++	unsigned int value;
++	static const struct watchdog_info ident = {
++		.options = WDIOF_CARDRESET,
++		.identity = "GPIO WDT",
++	};
++
++	switch (cmd) {
++	case WDIOC_GETSUPPORT:
++		if (copy_to_user(argp, &ident, sizeof(ident)))
++			return -EFAULT;
++		break;
++	case WDIOC_GETSTATUS:
++	case WDIOC_GETBOOTSTATUS:
++		put_user(0, p);
++		break;
++	case WDIOC_SETOPTIONS:
++		if (get_user(value, p))
++			return -EFAULT;
++		if (value & WDIOS_ENABLECARD)
++			gpio_wdt_start();
++		else if (value & WDIOS_DISABLECARD)
++			gpio_wdt_stop();
++		else
++			return -EINVAL;
++		return 0;
++	case WDIOC_KEEPALIVE:
++		gpio_wdt_reset();
++		break;
++	default:
++		return -ENOTTY;
++	}
++	return 0;
++}
++
++
++static ssize_t gpio_wdt_write(struct file *file, const char *buf,
++						size_t count, loff_t *ppos)
++{
++	if (!count)
++		return -EIO;
++	gpio_wdt_reset();
++	return count;
++}
++
++static const struct file_operations gpio_wdt_fops = {
++	.owner		= THIS_MODULE,
++	.llseek		= no_llseek,
++	.unlocked_ioctl	= gpio_wdt_ioctl,
++	.open		= gpio_wdt_open,
++	.write		= gpio_wdt_write,
++	.release	= gpio_wdt_release,
++};
++
++
++static struct miscdevice gpio_wdt_misc = {
++	.minor	= WATCHDOG_MINOR,
++	.name	= "watchdog",
++	.fops	= &gpio_wdt_fops,
++};
++
++
++static int gpio_wdt_probe(struct platform_device *pdev)
++{
++	int ret;
++	struct gpio_wdt_platform_data *gpio_wdt_data = pdev->dev.platform_data;
++
++	gpio_wdt_device.gpio = gpio_wdt_data->gpio;
++	gpio_wdt_device.interval = gpio_wdt_data->interval;
++	gpio_wdt_device.first_interval = gpio_wdt_data->first_interval;
++	if (gpio_wdt_device.first_interval <= 0) {
++		gpio_wdt_device.first_interval = gpio_wdt_device.interval;
++	}
++
++	ret = gpio_request(gpio_wdt_device.gpio, "gpio-wdt");
++	if (ret < 0) {
++		dev_err(&pdev->dev, "failed to request gpio");
++		return ret;
++	}
++
++	spin_lock_init(&gpio_wdt_device.lock);
++	init_completion(&gpio_wdt_device.stop);
++	gpio_wdt_device.queue = 0;
++	clear_bit(0, &gpio_wdt_device.inuse);
++	setup_timer(&gpio_wdt_device.timer, gpio_wdt_trigger, 0L);
++	gpio_wdt_device.default_ticks = ticks;
++
++	gpio_wdt_start();
++	dev_info(&pdev->dev, "GPIO Hardware Watchdog driver (gpio=%i interval=%i/%i)\n",
++		gpio_wdt_data->gpio, gpio_wdt_data->first_interval, gpio_wdt_data->interval);
++	return 0;
++}
++
++static int gpio_wdt_remove(struct platform_device *pdev)
++{
++	/* FIXME: do we need to lock this test ? */
++	if (gpio_wdt_device.queue) {
++		gpio_wdt_device.queue = 0;
++		wait_for_completion(&gpio_wdt_device.stop);
++	}
++
++	gpio_free(gpio_wdt_device.gpio);
++	misc_deregister(&gpio_wdt_misc);
++	return 0;
++}
++
++static struct platform_driver gpio_wdt_driver = {
++	.probe = gpio_wdt_probe,
++	.remove = gpio_wdt_remove,
++	.driver.name = "gpio-wdt",
++	.driver.owner = THIS_MODULE,
++};
++
++static int __init gpio_wdt_init(void)
++{
++	return platform_driver_register(&gpio_wdt_driver);
++}
++arch_initcall(gpio_wdt_init);
++
++/*
++ * We do wdt initialization in two steps: arch_initcall probes the wdt
++ * very early to start pinging the watchdog (misc devices are not yet
++ * available), and later module_init() just registers the misc device.
++ */
++static int gpio_wdt_init_late(void)
++{
++	int ret;
++
++	ret = misc_register(&gpio_wdt_misc);
++	if (ret < 0) {
++		pr_err("GPIO_WDT: failed to register misc device\n");
++		return ret;
++	}
++	return 0;
++}
++#ifndef MODULE
++module_init(gpio_wdt_init_late);
++#endif
++
++static void __exit gpio_wdt_exit(void)
++{
++	platform_driver_unregister(&gpio_wdt_driver);
++}
++module_exit(gpio_wdt_exit);
++
++MODULE_AUTHOR("Michael Stickel, Florian Fainelli, Mathias Adam");
++MODULE_DESCRIPTION("Driver for GPIO hardware watchdogs");
++MODULE_LICENSE("GPL");
++MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
++MODULE_ALIAS("platform:gpio-wdt");
+--- /dev/null
++++ b/include/linux/gpio_wdt.h
+@@ -0,0 +1,21 @@
++/*
++ *  Definitions for the GPIO watchdog driver
++ *
++ *  Copyright (C) 2013 Mathias Adam <m.adam--linux@adamis.de>
++ *
++ *  This program is free software; you can redistribute it and/or modify
++ *  it under the terms of the GNU General Public License version 2 as
++ *  published by the Free Software Foundation.
++ *
++ */
++
++#ifndef _GPIO_WDT_H_
++#define _GPIO_WDT_H_
++
++struct gpio_wdt_platform_data {
++	int	gpio;		/* GPIO line number */
++	int	interval;	/* watchdog reset interval in system ticks */
++	int	first_interval;	/* first wd reset interval in system ticks */
++};
++
++#endif /* _GPIO_WDT_H_ */