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277 lines
6.9 KiB
277 lines
6.9 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* PNX833x Hardware Watchdog Driver |
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* Copyright 2008 NXP Semiconductors |
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* Daniel Laird <[email protected]> |
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* Andre McCurdy <[email protected]> |
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* |
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* Heavily based upon - IndyDog 0.3 |
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* A Hardware Watchdog Device for SGI IP22 |
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* |
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* (c) Copyright 2002 Guido Guenther <[email protected]>, All Rights Reserved. |
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* |
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* based on softdog.c by Alan Cox <[email protected]> |
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*/ |
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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#include <linux/module.h> |
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#include <linux/moduleparam.h> |
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#include <linux/types.h> |
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#include <linux/kernel.h> |
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#include <linux/fs.h> |
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#include <linux/mm.h> |
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#include <linux/miscdevice.h> |
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#include <linux/watchdog.h> |
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#include <linux/notifier.h> |
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#include <linux/reboot.h> |
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#include <linux/init.h> |
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#include <asm/mach-pnx833x/pnx833x.h> |
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#define WATCHDOG_TIMEOUT 30 /* 30 sec Maximum timeout */ |
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#define WATCHDOG_COUNT_FREQUENCY 68000000U /* Watchdog counts at 68MHZ. */ |
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#define PNX_WATCHDOG_TIMEOUT (WATCHDOG_TIMEOUT * WATCHDOG_COUNT_FREQUENCY) |
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#define PNX_TIMEOUT_VALUE 2040000000U |
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/** CONFIG block */ |
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#define PNX833X_CONFIG (0x07000U) |
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#define PNX833X_CONFIG_CPU_WATCHDOG (0x54) |
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#define PNX833X_CONFIG_CPU_WATCHDOG_COMPARE (0x58) |
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#define PNX833X_CONFIG_CPU_COUNTERS_CONTROL (0x1c) |
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/** RESET block */ |
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#define PNX833X_RESET (0x08000U) |
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#define PNX833X_RESET_CONFIG (0x08) |
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static int pnx833x_wdt_alive; |
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/* Set default timeout in MHZ.*/ |
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static int pnx833x_wdt_timeout = PNX_WATCHDOG_TIMEOUT; |
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module_param(pnx833x_wdt_timeout, int, 0); |
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MODULE_PARM_DESC(timeout, "Watchdog timeout in Mhz. (68Mhz clock), default=" |
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__MODULE_STRING(PNX_TIMEOUT_VALUE) "(30 seconds)."); |
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static bool nowayout = WATCHDOG_NOWAYOUT; |
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module_param(nowayout, bool, 0); |
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" |
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
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#define START_DEFAULT 1 |
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static int start_enabled = START_DEFAULT; |
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module_param(start_enabled, int, 0); |
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MODULE_PARM_DESC(start_enabled, "Watchdog is started on module insertion " |
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"(default=" __MODULE_STRING(START_DEFAULT) ")"); |
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static void pnx833x_wdt_start(void) |
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{ |
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/* Enable watchdog causing reset. */ |
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PNX833X_REG(PNX833X_RESET + PNX833X_RESET_CONFIG) |= 0x1; |
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/* Set timeout.*/ |
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PNX833X_REG(PNX833X_CONFIG + |
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PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout; |
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/* Enable watchdog. */ |
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PNX833X_REG(PNX833X_CONFIG + |
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PNX833X_CONFIG_CPU_COUNTERS_CONTROL) |= 0x1; |
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pr_info("Started watchdog timer\n"); |
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} |
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static void pnx833x_wdt_stop(void) |
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{ |
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/* Disable watchdog causing reset. */ |
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PNX833X_REG(PNX833X_RESET + PNX833X_CONFIG) &= 0xFFFFFFFE; |
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/* Disable watchdog.*/ |
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PNX833X_REG(PNX833X_CONFIG + |
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PNX833X_CONFIG_CPU_COUNTERS_CONTROL) &= 0xFFFFFFFE; |
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pr_info("Stopped watchdog timer\n"); |
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} |
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static void pnx833x_wdt_ping(void) |
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{ |
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PNX833X_REG(PNX833X_CONFIG + |
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PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout; |
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} |
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/* |
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* Allow only one person to hold it open |
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*/ |
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static int pnx833x_wdt_open(struct inode *inode, struct file *file) |
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{ |
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if (test_and_set_bit(0, &pnx833x_wdt_alive)) |
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return -EBUSY; |
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if (nowayout) |
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__module_get(THIS_MODULE); |
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/* Activate timer */ |
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if (!start_enabled) |
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pnx833x_wdt_start(); |
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pnx833x_wdt_ping(); |
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pr_info("Started watchdog timer\n"); |
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return stream_open(inode, file); |
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} |
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static int pnx833x_wdt_release(struct inode *inode, struct file *file) |
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{ |
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/* Shut off the timer. |
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* Lock it in if it's a module and we defined ...NOWAYOUT */ |
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if (!nowayout) |
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pnx833x_wdt_stop(); /* Turn the WDT off */ |
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clear_bit(0, &pnx833x_wdt_alive); |
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return 0; |
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} |
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static ssize_t pnx833x_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) |
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{ |
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/* Refresh the timer. */ |
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if (len) |
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pnx833x_wdt_ping(); |
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return len; |
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} |
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static long pnx833x_wdt_ioctl(struct file *file, unsigned int cmd, |
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unsigned long arg) |
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{ |
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int options, new_timeout = 0; |
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uint32_t timeout, timeout_left = 0; |
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static const struct watchdog_info ident = { |
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.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT, |
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.firmware_version = 0, |
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.identity = "Hardware Watchdog for PNX833x", |
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}; |
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switch (cmd) { |
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default: |
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return -ENOTTY; |
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case WDIOC_GETSUPPORT: |
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if (copy_to_user((struct watchdog_info *)arg, |
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&ident, sizeof(ident))) |
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return -EFAULT; |
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return 0; |
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case WDIOC_GETSTATUS: |
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case WDIOC_GETBOOTSTATUS: |
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return put_user(0, (int *)arg); |
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case WDIOC_SETOPTIONS: |
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if (get_user(options, (int *)arg)) |
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return -EFAULT; |
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if (options & WDIOS_DISABLECARD) |
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pnx833x_wdt_stop(); |
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if (options & WDIOS_ENABLECARD) |
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pnx833x_wdt_start(); |
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return 0; |
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case WDIOC_KEEPALIVE: |
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pnx833x_wdt_ping(); |
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return 0; |
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case WDIOC_SETTIMEOUT: |
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{ |
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if (get_user(new_timeout, (int *)arg)) |
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return -EFAULT; |
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pnx833x_wdt_timeout = new_timeout; |
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PNX833X_REG(PNX833X_CONFIG + |
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PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = new_timeout; |
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return put_user(new_timeout, (int *)arg); |
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} |
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case WDIOC_GETTIMEOUT: |
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timeout = PNX833X_REG(PNX833X_CONFIG + |
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PNX833X_CONFIG_CPU_WATCHDOG_COMPARE); |
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return put_user(timeout, (int *)arg); |
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case WDIOC_GETTIMELEFT: |
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timeout_left = PNX833X_REG(PNX833X_CONFIG + |
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PNX833X_CONFIG_CPU_WATCHDOG); |
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return put_user(timeout_left, (int *)arg); |
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} |
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} |
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static int pnx833x_wdt_notify_sys(struct notifier_block *this, |
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unsigned long code, void *unused) |
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{ |
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if (code == SYS_DOWN || code == SYS_HALT) |
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pnx833x_wdt_stop(); /* Turn the WDT off */ |
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return NOTIFY_DONE; |
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} |
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static const struct file_operations pnx833x_wdt_fops = { |
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.owner = THIS_MODULE, |
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.llseek = no_llseek, |
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.write = pnx833x_wdt_write, |
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.unlocked_ioctl = pnx833x_wdt_ioctl, |
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.compat_ioctl = compat_ptr_ioctl, |
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.open = pnx833x_wdt_open, |
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.release = pnx833x_wdt_release, |
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}; |
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static struct miscdevice pnx833x_wdt_miscdev = { |
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.minor = WATCHDOG_MINOR, |
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.name = "watchdog", |
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.fops = &pnx833x_wdt_fops, |
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}; |
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static struct notifier_block pnx833x_wdt_notifier = { |
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.notifier_call = pnx833x_wdt_notify_sys, |
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}; |
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static int __init watchdog_init(void) |
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{ |
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int ret, cause; |
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/* Lets check the reason for the reset.*/ |
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cause = PNX833X_REG(PNX833X_RESET); |
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/*If bit 31 is set then watchdog was cause of reset.*/ |
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if (cause & 0x80000000) { |
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pr_info("The system was previously reset due to the watchdog firing - please investigate...\n"); |
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} |
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ret = register_reboot_notifier(&pnx833x_wdt_notifier); |
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if (ret) { |
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pr_err("cannot register reboot notifier (err=%d)\n", ret); |
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return ret; |
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} |
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ret = misc_register(&pnx833x_wdt_miscdev); |
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if (ret) { |
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pr_err("cannot register miscdev on minor=%d (err=%d)\n", |
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WATCHDOG_MINOR, ret); |
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unregister_reboot_notifier(&pnx833x_wdt_notifier); |
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return ret; |
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} |
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pr_info("Hardware Watchdog Timer for PNX833x: Version 0.1\n"); |
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if (start_enabled) |
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pnx833x_wdt_start(); |
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return 0; |
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} |
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static void __exit watchdog_exit(void) |
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{ |
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misc_deregister(&pnx833x_wdt_miscdev); |
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unregister_reboot_notifier(&pnx833x_wdt_notifier); |
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} |
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module_init(watchdog_init); |
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module_exit(watchdog_exit); |
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MODULE_AUTHOR("Daniel Laird/Andre McCurdy"); |
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MODULE_DESCRIPTION("Hardware Watchdog Device for PNX833x"); |
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MODULE_LICENSE("GPL");
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