[LEDE-DEV] [PATCH] cns3xxx: restore mpcore watchdog
Koen Vandeputte
koen.vandeputte at ncentric.com
Tue Jan 10 05:34:57 PST 2017
Adds the mpcore watchdog driver for kernel 4.4 as it was originally
present up to kernel 3.12
- Disabled by default for now, but can be simply enabled in kernelconfig
- Currently does not contain the latest patches as mentioned here:
https://git.kernel.org/cgit/linux/kernel/git/next/linux-
next.git/commit/?id=6e63a3a294fdf91eaaac1061a9c7a5f53d16ac25
Tested on cns3xxx (GW2388)
[ 0.700000] mpcore_wdt: MPcore Watchdog Timer: 0.1. mpcore_noboot=0
mpcore_margin=60 sec (nowayout= 1)
[ 3.490000] mpcore_wdt mpcore_wdt: enabling watchdog
[ 3.490000] init: - watchdog -
[ 8.750000] procd: - watchdog -
Signed-off-by: Koen Vandeputte <koen.vandeputte at ncentric.com>
---
target/linux/cns3xxx/config-4.4 | 1 +
.../patches-4.4/300-restore-mpcore-watchdog.patch | 502 +++++++++++++++++++++
2 files changed, 503 insertions(+)
create mode 100644 target/linux/cns3xxx/patches-4.4/300-restore-mpcore-watchdog.patch
diff --git a/target/linux/cns3xxx/config-4.4 b/target/linux/cns3xxx/config-4.4
index 4745f4e..ffc1f02 100644
--- a/target/linux/cns3xxx/config-4.4
+++ b/target/linux/cns3xxx/config-4.4
@@ -182,6 +182,7 @@ CONFIG_MMC_SDHCI_CNS3XXX=y
CONFIG_MMC_SDHCI_PLTFM=y
# CONFIG_MMC_TIFM_SD is not set
CONFIG_MODULES_USE_ELF_REL=y
+# CONFIG_MPCORE_WATCHDOG is not set
CONFIG_MTD_M25P80=y
# CONFIG_MTD_OF_PARTS is not set
CONFIG_MTD_PHYSMAP=y
diff --git a/target/linux/cns3xxx/patches-4.4/300-restore-mpcore-watchdog.patch b/target/linux/cns3xxx/patches-4.4/300-restore-mpcore-watchdog.patch
new file mode 100644
index 0000000..156dcaa
--- /dev/null
+++ b/target/linux/cns3xxx/patches-4.4/300-restore-mpcore-watchdog.patch
@@ -0,0 +1,502 @@
+--- a/Documentation/watchdog/watchdog-parameters.txt
++++ b/Documentation/watchdog/watchdog-parameters.txt
+@@ -196,6 +196,14 @@ reset: Watchdog Interrupt/Reset Mode. 0
+ nowayout: Watchdog cannot be stopped once started
+ (default=kernel config parameter)
+ -------------------------------------------------
++mpcore_wdt:
++mpcore_margin: MPcore timer margin in seconds.
++ (0 < mpcore_margin < 65536, default=60)
++nowayout: Watchdog cannot be stopped once started
++ (default=kernel config parameter)
++mpcore_noboot: MPcore watchdog action, set to 1 to ignore reboots,
++ 0 to reboot (default=0
++--------------------------------------------------
+ mv64x60_wdt:
+ nowayout: Watchdog cannot be stopped once started
+ (default=kernel config parameter)
+--- a/drivers/watchdog/Kconfig
++++ b/drivers/watchdog/Kconfig
+@@ -297,6 +297,15 @@ config DW_WATCHDOG
+ To compile this driver as a module, choose M here: the
+ module will be called dw_wdt.
+
++config MPCORE_WATCHDOG
++ tristate "MPcore watchdog"
++ depends on HAVE_ARM_TWD
++ help
++ Watchdog timer embedded into the MPcore system.
++
++ To compile this driver as a module, choose M here: the
++ module will be called mpcore_wdt.
++
+ config EP93XX_WATCHDOG
+ tristate "EP93xx Watchdog"
+ depends on ARCH_EP93XX
+--- a/drivers/watchdog/Makefile
++++ b/drivers/watchdog/Makefile
+@@ -43,6 +43,7 @@ obj-$(CONFIG_S3C2410_WATCHDOG) += s3c241
+ obj-$(CONFIG_SA1100_WATCHDOG) += sa1100_wdt.o
+ obj-$(CONFIG_SAMA5D4_WATCHDOG) += sama5d4_wdt.o
+ obj-$(CONFIG_DW_WATCHDOG) += dw_wdt.o
++obj-$(CONFIG_MPCORE_WATCHDOG) += mpcore_wdt.o
+ obj-$(CONFIG_EP93XX_WATCHDOG) += ep93xx_wdt.o
+ obj-$(CONFIG_PNX4008_WATCHDOG) += pnx4008_wdt.o
+ obj-$(CONFIG_IOP_WATCHDOG) += iop_wdt.o
+--- /dev/null
++++ b/drivers/watchdog/mpcore_wdt.c
+@@ -0,0 +1,454 @@
++/*
++ * Watchdog driver for the mpcore watchdog timer
++ *
++ * (c) Copyright 2004 ARM Limited
++ *
++ * Based on the SoftDog driver:
++ * (c) Copyright 1996 Alan Cox <alan at lxorguk.ukuu.org.uk>,
++ * All Rights Reserved.
++ *
++ * 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 Alan Cox nor CymruNet Ltd. admit liability nor provide
++ * warranty for any of this software. This material is provided
++ * "AS-IS" and at no charge.
++ *
++ * (c) Copyright 1995 Alan Cox <alan at lxorguk.ukuu.org.uk>
++ *
++ */
++
++#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
++
++#include <linux/module.h>
++#include <linux/moduleparam.h>
++#include <linux/types.h>
++#include <linux/miscdevice.h>
++#include <linux/watchdog.h>
++#include <linux/fs.h>
++#include <linux/reboot.h>
++#include <linux/init.h>
++#include <linux/interrupt.h>
++#include <linux/platform_device.h>
++#include <linux/uaccess.h>
++#include <linux/slab.h>
++#include <linux/io.h>
++
++#include <asm/smp_twd.h>
++
++struct mpcore_wdt {
++ unsigned long timer_alive;
++ struct device *dev;
++ void __iomem *base;
++ int irq;
++ unsigned int perturb;
++ char expect_close;
++};
++
++static struct platform_device *mpcore_wdt_pdev;
++static DEFINE_SPINLOCK(wdt_lock);
++
++#define TIMER_MARGIN 60
++static int mpcore_margin = TIMER_MARGIN;
++module_param(mpcore_margin, int, 0);
++MODULE_PARM_DESC(mpcore_margin,
++ "MPcore timer margin in seconds. (0 < mpcore_margin < 65536, default="
++ __MODULE_STRING(TIMER_MARGIN) ")");
++
++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) ")");
++
++#define ONLY_TESTING 0
++static int mpcore_noboot = ONLY_TESTING;
++module_param(mpcore_noboot, int, 0);
++MODULE_PARM_DESC(mpcore_noboot, "MPcore watchdog action, "
++ "set to 1 to ignore reboots, 0 to reboot (default="
++ __MODULE_STRING(ONLY_TESTING) ")");
++
++/*
++ * This is the interrupt handler. Note that we only use this
++ * in testing mode, so don't actually do a reboot here.
++ */
++static irqreturn_t mpcore_wdt_fire(int irq, void *arg)
++{
++ struct mpcore_wdt *wdt = arg;
++
++ /* Check it really was our interrupt */
++ if (readl(wdt->base + TWD_WDOG_INTSTAT)) {
++ dev_crit(wdt->dev, "Triggered - Reboot ignored\n");
++ /* Clear the interrupt on the watchdog */
++ writel(1, wdt->base + TWD_WDOG_INTSTAT);
++ return IRQ_HANDLED;
++ }
++ return IRQ_NONE;
++}
++
++/*
++ * mpcore_wdt_keepalive - reload the timer
++ *
++ * Note that the spec says a DIFFERENT value must be written to the reload
++ * register each time. The "perturb" variable deals with this by adding 1
++ * to the count every other time the function is called.
++ */
++static void mpcore_wdt_keepalive(struct mpcore_wdt *wdt)
++{
++ unsigned long count;
++
++ spin_lock(&wdt_lock);
++ /* Assume prescale is set to 256 */
++ count = __raw_readl(wdt->base + TWD_WDOG_COUNTER);
++ count = (0xFFFFFFFFU - count) * (HZ / 5);
++ count = (count / 256) * mpcore_margin;
++
++ /* Reload the counter */
++ writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD);
++ wdt->perturb = wdt->perturb ? 0 : 1;
++ spin_unlock(&wdt_lock);
++}
++
++static void mpcore_wdt_stop(struct mpcore_wdt *wdt)
++{
++ spin_lock(&wdt_lock);
++ writel(0x12345678, wdt->base + TWD_WDOG_DISABLE);
++ writel(0x87654321, wdt->base + TWD_WDOG_DISABLE);
++ writel(0x0, wdt->base + TWD_WDOG_CONTROL);
++ spin_unlock(&wdt_lock);
++}
++
++static void mpcore_wdt_start(struct mpcore_wdt *wdt)
++{
++ dev_info(wdt->dev, "enabling watchdog\n");
++
++ /* This loads the count register but does NOT start the count yet */
++ mpcore_wdt_keepalive(wdt);
++
++ if (mpcore_noboot) {
++ /* Enable watchdog - prescale=256, watchdog mode=0, enable=1 */
++ writel(0x0000FF01, wdt->base + TWD_WDOG_CONTROL);
++ } else {
++ /* Enable watchdog - prescale=256, watchdog mode=1, enable=1 */
++ writel(0x0000FF09, wdt->base + TWD_WDOG_CONTROL);
++ }
++}
++
++static int mpcore_wdt_set_heartbeat(int t)
++{
++ if (t < 0x0001 || t > 0xFFFF)
++ return -EINVAL;
++
++ mpcore_margin = t;
++ return 0;
++}
++
++/*
++ * /dev/watchdog handling
++ */
++static int mpcore_wdt_open(struct inode *inode, struct file *file)
++{
++ struct mpcore_wdt *wdt = platform_get_drvdata(mpcore_wdt_pdev);
++
++ if (test_and_set_bit(0, &wdt->timer_alive))
++ return -EBUSY;
++
++ if (nowayout)
++ __module_get(THIS_MODULE);
++
++ file->private_data = wdt;
++
++ /*
++ * Activate timer
++ */
++ mpcore_wdt_start(wdt);
++
++ return nonseekable_open(inode, file);
++}
++
++static int mpcore_wdt_release(struct inode *inode, struct file *file)
++{
++ struct mpcore_wdt *wdt = file->private_data;
++
++ /*
++ * Shut off the timer.
++ * Lock it in if it's a module and we set nowayout
++ */
++ if (wdt->expect_close == 42)
++ mpcore_wdt_stop(wdt);
++ else {
++ dev_crit(wdt->dev,
++ "unexpected close, not stopping watchdog!\n");
++ mpcore_wdt_keepalive(wdt);
++ }
++ clear_bit(0, &wdt->timer_alive);
++ wdt->expect_close = 0;
++ return 0;
++}
++
++static ssize_t mpcore_wdt_write(struct file *file, const char *data,
++ size_t len, loff_t *ppos)
++{
++ struct mpcore_wdt *wdt = file->private_data;
++
++ /*
++ * Refresh the timer.
++ */
++ if (len) {
++ if (!nowayout) {
++ size_t i;
++
++ /* In case it was set long ago */
++ wdt->expect_close = 0;
++
++ for (i = 0; i != len; i++) {
++ char c;
++
++ if (get_user(c, data + i))
++ return -EFAULT;
++ if (c == 'V')
++ wdt->expect_close = 42;
++ }
++ }
++ mpcore_wdt_keepalive(wdt);
++ }
++ return len;
++}
++
++static const struct watchdog_info ident = {
++ .options = WDIOF_SETTIMEOUT |
++ WDIOF_KEEPALIVEPING |
++ WDIOF_MAGICCLOSE,
++ .identity = "MPcore Watchdog",
++};
++
++static long mpcore_wdt_ioctl(struct file *file, unsigned int cmd,
++ unsigned long arg)
++{
++ struct mpcore_wdt *wdt = file->private_data;
++ int ret;
++ union {
++ struct watchdog_info ident;
++ int i;
++ } uarg;
++
++ if (_IOC_DIR(cmd) && _IOC_SIZE(cmd) > sizeof(uarg))
++ return -ENOTTY;
++
++ if (_IOC_DIR(cmd) & _IOC_WRITE) {
++ ret = copy_from_user(&uarg, (void __user *)arg, _IOC_SIZE(cmd));
++ if (ret)
++ return -EFAULT;
++ }
++
++ switch (cmd) {
++ case WDIOC_GETSUPPORT:
++ uarg.ident = ident;
++ ret = 0;
++ break;
++
++ case WDIOC_GETSTATUS:
++ case WDIOC_GETBOOTSTATUS:
++ uarg.i = 0;
++ ret = 0;
++ break;
++
++ case WDIOC_SETOPTIONS:
++ ret = -EINVAL;
++ if (uarg.i & WDIOS_DISABLECARD) {
++ mpcore_wdt_stop(wdt);
++ ret = 0;
++ }
++ if (uarg.i & WDIOS_ENABLECARD) {
++ mpcore_wdt_start(wdt);
++ ret = 0;
++ }
++ break;
++
++ case WDIOC_KEEPALIVE:
++ mpcore_wdt_keepalive(wdt);
++ ret = 0;
++ break;
++
++ case WDIOC_SETTIMEOUT:
++ ret = mpcore_wdt_set_heartbeat(uarg.i);
++ if (ret)
++ break;
++
++ mpcore_wdt_keepalive(wdt);
++ /* Fall */
++ case WDIOC_GETTIMEOUT:
++ uarg.i = mpcore_margin;
++ ret = 0;
++ break;
++
++ default:
++ return -ENOTTY;
++ }
++
++ if (ret == 0 && _IOC_DIR(cmd) & _IOC_READ) {
++ ret = copy_to_user((void __user *)arg, &uarg, _IOC_SIZE(cmd));
++ if (ret)
++ ret = -EFAULT;
++ }
++ return ret;
++}
++
++/*
++ * System shutdown handler. Turn off the watchdog if we're
++ * restarting or halting the system.
++ */
++static void mpcore_wdt_shutdown(struct platform_device *pdev)
++{
++ struct mpcore_wdt *wdt = platform_get_drvdata(pdev);
++
++ if (system_state == SYSTEM_RESTART || system_state == SYSTEM_HALT)
++ mpcore_wdt_stop(wdt);
++}
++
++/*
++ * Kernel Interfaces
++ */
++static const struct file_operations mpcore_wdt_fops = {
++ .owner = THIS_MODULE,
++ .llseek = no_llseek,
++ .write = mpcore_wdt_write,
++ .unlocked_ioctl = mpcore_wdt_ioctl,
++ .open = mpcore_wdt_open,
++ .release = mpcore_wdt_release,
++};
++
++static struct miscdevice mpcore_wdt_miscdev = {
++ .minor = WATCHDOG_MINOR,
++ .name = "watchdog",
++ .fops = &mpcore_wdt_fops,
++};
++
++static int mpcore_wdt_probe(struct platform_device *pdev)
++{
++ struct mpcore_wdt *wdt;
++ struct resource *res;
++ int ret;
++
++ /* We only accept one device, and it must have an id of -1 */
++ if (pdev->id != -1)
++ return -ENODEV;
++
++ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
++ if (!res)
++ return -ENODEV;
++
++ wdt = devm_kzalloc(&pdev->dev, sizeof(struct mpcore_wdt), GFP_KERNEL);
++ if (!wdt)
++ return -ENOMEM;
++
++ wdt->dev = &pdev->dev;
++ wdt->irq = platform_get_irq(pdev, 0);
++ if (wdt->irq >= 0) {
++ ret = devm_request_irq(wdt->dev, wdt->irq, mpcore_wdt_fire, 0,
++ "mpcore_wdt", wdt);
++ if (ret) {
++ dev_err(wdt->dev,
++ "cannot register IRQ%d for watchdog\n",
++ wdt->irq);
++ return ret;
++ }
++ }
++
++ wdt->base = devm_ioremap(wdt->dev, res->start, resource_size(res));
++ if (!wdt->base)
++ return -ENOMEM;
++
++ mpcore_wdt_miscdev.parent = &pdev->dev;
++ ret = misc_register(&mpcore_wdt_miscdev);
++ if (ret) {
++ dev_err(wdt->dev,
++ "cannot register miscdev on minor=%d (err=%d)\n",
++ WATCHDOG_MINOR, ret);
++ return ret;
++ }
++
++ mpcore_wdt_stop(wdt);
++ platform_set_drvdata(pdev, wdt);
++ mpcore_wdt_pdev = pdev;
++
++ return 0;
++}
++
++static int mpcore_wdt_remove(struct platform_device *pdev)
++{
++ misc_deregister(&mpcore_wdt_miscdev);
++
++ mpcore_wdt_pdev = NULL;
++
++ return 0;
++}
++
++#ifdef CONFIG_PM
++static int mpcore_wdt_suspend(struct platform_device *pdev, pm_message_t msg)
++{
++ struct mpcore_wdt *wdt = platform_get_drvdata(pdev);
++ mpcore_wdt_stop(wdt); /* Turn the WDT off */
++ return 0;
++}
++
++static int mpcore_wdt_resume(struct platform_device *pdev)
++{
++ struct mpcore_wdt *wdt = platform_get_drvdata(pdev);
++ /* re-activate timer */
++ if (test_bit(0, &wdt->timer_alive))
++ mpcore_wdt_start(wdt);
++ return 0;
++}
++#else
++#define mpcore_wdt_suspend NULL
++#define mpcore_wdt_resume NULL
++#endif
++
++/* work with hotplug and coldplug */
++MODULE_ALIAS("platform:mpcore_wdt");
++
++static struct platform_driver mpcore_wdt_driver = {
++ .probe = mpcore_wdt_probe,
++ .remove = mpcore_wdt_remove,
++ .suspend = mpcore_wdt_suspend,
++ .resume = mpcore_wdt_resume,
++ .shutdown = mpcore_wdt_shutdown,
++ .driver = {
++ .owner = THIS_MODULE,
++ .name = "mpcore_wdt",
++ },
++};
++
++static int __init mpcore_wdt_init(void)
++{
++ /*
++ * Check that the margin value is within it's range;
++ * if not reset to the default
++ */
++ if (mpcore_wdt_set_heartbeat(mpcore_margin)) {
++ mpcore_wdt_set_heartbeat(TIMER_MARGIN);
++ pr_info("mpcore_margin value must be 0 < mpcore_margin < 65536, using %d\n",
++ TIMER_MARGIN);
++ }
++
++ pr_info("MPcore Watchdog Timer: 0.1. mpcore_noboot=%d mpcore_margin=%d sec (nowayout= %d)\n",
++ mpcore_noboot, mpcore_margin, nowayout);
++
++ return platform_driver_register(&mpcore_wdt_driver);
++}
++
++static void __exit mpcore_wdt_exit(void)
++{
++ platform_driver_unregister(&mpcore_wdt_driver);
++}
++
++module_init(mpcore_wdt_init);
++module_exit(mpcore_wdt_exit);
++
++MODULE_AUTHOR("ARM Limited");
++MODULE_DESCRIPTION("MPcore Watchdog Device Driver");
++MODULE_LICENSE("GPL");
++MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
--
2.7.4
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