--- /dev/null
+/*
+ * Broadcom BCM63xx SoC watchdog driver
+ *
+ * Copyright (C) 2007, Miguel Gaio <miguel.gaio@efixo.com>
+ * Copyright (C) 2008, 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.
+ */
+
+#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(unsigned long 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 nonseekable_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;
+
+ setup_timer(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0L);
+
+ 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");
Code Review / kvmfornfv.git / blobdiff