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https://github.com/raspberrypi/linux.git
synced 2025-12-06 10:00:17 +00:00
bcm2708 watchdog driver
Signed-off-by: popcornmix <popcornmix@gmail.com>
This commit is contained in:
popcornmix
@@ -451,6 +451,12 @@ config RETU_WATCHDOG
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To compile this driver as a module, choose M here: the
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module will be called retu_wdt.
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config BCM2708_WDT
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tristate "BCM2708 Watchdog"
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depends on ARCH_BCM2708 || ARCH_BCM2709
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help
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Enables BCM2708 watchdog support.
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config MOXART_WDT
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tristate "MOXART watchdog"
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depends on ARCH_MOXART
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@@ -1216,7 +1222,7 @@ config BCM63XX_WDT
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config BCM2835_WDT
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tristate "Broadcom BCM2835 hardware watchdog"
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depends on ARCH_BCM2835
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depends on ARCH_BCM2835 || ARCH_BCM2708 || ARCH_BCM2709
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select WATCHDOG_CORE
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help
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Watchdog driver for the built in watchdog hardware in Broadcom
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@@ -56,6 +56,7 @@ obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_wdt.o
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obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o
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obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o
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obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o
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obj-$(CONFIG_BCM2708_WDT) += bcm2708_wdog.o
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obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o
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obj-$(CONFIG_MOXART_WDT) += moxart_wdt.o
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obj-$(CONFIG_SIRFSOC_WATCHDOG) += sirfsoc_wdt.o
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382
drivers/watchdog/bcm2708_wdog.c
Normal file
382
drivers/watchdog/bcm2708_wdog.c
Normal file
@@ -0,0 +1,382 @@
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/*
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* Broadcom BCM2708 watchdog driver.
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*
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* (c) Copyright 2010 Broadcom Europe Ltd
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* BCM2708 watchdog driver. Loosely based on wdt driver.
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*/
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#include <linux/interrupt.h>
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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/miscdevice.h>
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#include <linux/watchdog.h>
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#include <linux/fs.h>
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#include <linux/ioport.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 <linux/io.h>
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#include <linux/uaccess.h>
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#include <mach/platform.h>
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#define SECS_TO_WDOG_TICKS(x) ((x) << 16)
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#define WDOG_TICKS_TO_SECS(x) ((x) >> 16)
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static unsigned long wdog_is_open;
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static uint32_t wdog_ticks; /* Ticks to load into wdog timer */
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static char expect_close;
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/*
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* Module parameters
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*/
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#define WD_TIMO 10 /* Default heartbeat = 60 seconds */
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static int heartbeat = WD_TIMO; /* Heartbeat in seconds */
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module_param(heartbeat, int, 0);
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MODULE_PARM_DESC(heartbeat,
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"Watchdog heartbeat in seconds. (0 < heartbeat < 65536, default="
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__MODULE_STRING(WD_TIMO) ")");
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static int nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, int, 0);
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MODULE_PARM_DESC(nowayout,
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"Watchdog cannot be stopped once started (default="
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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static DEFINE_SPINLOCK(wdog_lock);
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/**
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* Start the watchdog driver.
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*/
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static int wdog_start(unsigned long timeout)
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{
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uint32_t cur;
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unsigned long flags;
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spin_lock_irqsave(&wdog_lock, flags);
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/* enable the watchdog */
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iowrite32(PM_PASSWORD | (timeout & PM_WDOG_TIME_SET),
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__io_address(PM_WDOG));
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cur = ioread32(__io_address(PM_RSTC));
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iowrite32(PM_PASSWORD | (cur & PM_RSTC_WRCFG_CLR) |
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PM_RSTC_WRCFG_FULL_RESET, __io_address(PM_RSTC));
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spin_unlock_irqrestore(&wdog_lock, flags);
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return 0;
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}
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/**
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* Stop the watchdog driver.
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*/
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static int wdog_stop(void)
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{
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iowrite32(PM_PASSWORD | PM_RSTC_RESET, __io_address(PM_RSTC));
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printk(KERN_INFO "watchdog stopped\n");
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return 0;
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}
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/**
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* Reload counter one with the watchdog heartbeat. We don't bother
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* reloading the cascade counter.
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*/
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static void wdog_ping(void)
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{
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wdog_start(wdog_ticks);
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}
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/**
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* @t: the new heartbeat value that needs to be set.
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*
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* Set a new heartbeat value for the watchdog device. If the heartbeat
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* value is incorrect we keep the old value and return -EINVAL. If
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* successful we return 0.
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*/
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static int wdog_set_heartbeat(int t)
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{
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if (t < 1 || t > WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET))
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return -EINVAL;
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heartbeat = t;
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wdog_ticks = SECS_TO_WDOG_TICKS(t);
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return 0;
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}
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/**
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* @file: file handle to the watchdog
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* @buf: buffer to write (unused as data does not matter here
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* @count: count of bytes
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* @ppos: pointer to the position to write. No seeks allowed
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*
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* A write to a watchdog device is defined as a keepalive signal.
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*
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* if 'nowayout' is set then normally a close() is ignored. But
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* if you write 'V' first then the close() will stop the timer.
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*/
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static ssize_t wdog_write(struct file *file, const char __user *buf,
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size_t count, loff_t *ppos)
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{
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if (count) {
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if (!nowayout) {
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size_t i;
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/* In case it was set long ago */
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expect_close = 0;
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for (i = 0; i != count; i++) {
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char c;
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if (get_user(c, buf + i))
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return -EFAULT;
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if (c == 'V')
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expect_close = 42;
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}
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}
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wdog_ping();
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}
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return count;
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}
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static int wdog_get_status(void)
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{
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unsigned long flags;
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int status = 0;
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spin_lock_irqsave(&wdog_lock, flags);
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/* FIXME: readback reset reason */
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spin_unlock_irqrestore(&wdog_lock, flags);
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return status;
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}
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static uint32_t wdog_get_remaining(void)
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{
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uint32_t ret = ioread32(__io_address(PM_WDOG));
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return ret & PM_WDOG_TIME_SET;
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}
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/**
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* @file: file handle to the device
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* @cmd: watchdog command
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* @arg: argument pointer
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*
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* The watchdog API defines a common set of functions for all watchdogs
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* according to their available features. We only actually usefully support
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* querying capabilities and current status.
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*/
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static long wdog_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
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{
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void __user *argp = (void __user *)arg;
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int __user *p = argp;
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int new_heartbeat;
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int status;
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int options;
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uint32_t remaining;
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struct watchdog_info ident = {
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.options = WDIOF_SETTIMEOUT|
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WDIOF_MAGICCLOSE|
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WDIOF_KEEPALIVEPING,
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.firmware_version = 1,
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.identity = "BCM2708",
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};
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switch (cmd) {
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case WDIOC_GETSUPPORT:
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return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
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case WDIOC_GETSTATUS:
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status = wdog_get_status();
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return put_user(status, p);
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case WDIOC_GETBOOTSTATUS:
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return put_user(0, p);
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case WDIOC_KEEPALIVE:
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wdog_ping();
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return 0;
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case WDIOC_SETTIMEOUT:
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if (get_user(new_heartbeat, p))
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return -EFAULT;
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if (wdog_set_heartbeat(new_heartbeat))
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return -EINVAL;
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wdog_ping();
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/* Fall */
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case WDIOC_GETTIMEOUT:
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return put_user(heartbeat, p);
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case WDIOC_GETTIMELEFT:
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remaining = WDOG_TICKS_TO_SECS(wdog_get_remaining());
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return put_user(remaining, p);
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case WDIOC_SETOPTIONS:
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if (get_user(options, p))
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return -EFAULT;
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if (options & WDIOS_DISABLECARD)
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wdog_stop();
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if (options & WDIOS_ENABLECARD)
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wdog_start(wdog_ticks);
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return 0;
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default:
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return -ENOTTY;
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}
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}
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/**
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* @inode: inode of device
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* @file: file handle to device
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*
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* The watchdog device has been opened. The watchdog device is single
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* open and on opening we load the counters.
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*/
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static int wdog_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(0, &wdog_is_open))
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return -EBUSY;
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/*
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* Activate
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*/
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wdog_start(wdog_ticks);
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return nonseekable_open(inode, file);
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}
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/**
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* @inode: inode to board
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* @file: file handle to board
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*
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* The watchdog has a configurable API. There is a religious dispute
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* between people who want their watchdog to be able to shut down and
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* those who want to be sure if the watchdog manager dies the machine
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* reboots. In the former case we disable the counters, in the latter
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* case you have to open it again very soon.
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*/
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static int wdog_release(struct inode *inode, struct file *file)
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{
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if (expect_close == 42) {
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wdog_stop();
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} else {
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printk(KERN_CRIT
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"wdt: WDT device closed unexpectedly. WDT will not stop!\n");
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wdog_ping();
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}
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clear_bit(0, &wdog_is_open);
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expect_close = 0;
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return 0;
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}
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/**
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* @this: our notifier block
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* @code: the event being reported
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* @unused: unused
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*
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* Our notifier is called on system shutdowns. Turn the watchdog
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* off so that it does not fire during the next reboot.
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*/
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static int wdog_notify_sys(struct notifier_block *this, unsigned long code,
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void *unused)
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{
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if (code == SYS_DOWN || code == SYS_HALT)
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wdog_stop();
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return NOTIFY_DONE;
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}
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/*
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* Kernel Interfaces
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*/
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static const struct file_operations wdog_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = wdog_write,
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.unlocked_ioctl = wdog_ioctl,
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.open = wdog_open,
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.release = wdog_release,
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};
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static struct miscdevice wdog_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &wdog_fops,
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};
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/*
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* The WDT card needs to learn about soft shutdowns in order to
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* turn the timebomb registers off.
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*/
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static struct notifier_block wdog_notifier = {
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.notifier_call = wdog_notify_sys,
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};
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/**
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* cleanup_module:
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*
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* Unload the watchdog. You cannot do this with any file handles open.
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* If your watchdog is set to continue ticking on close and you unload
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* it, well it keeps ticking. We won't get the interrupt but the board
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* will not touch PC memory so all is fine. You just have to load a new
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* module in 60 seconds or reboot.
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*/
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static void __exit wdog_exit(void)
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{
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misc_deregister(&wdog_miscdev);
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unregister_reboot_notifier(&wdog_notifier);
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}
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static int __init wdog_init(void)
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{
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int ret;
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/* Check that the heartbeat value is within it's range;
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if not reset to the default */
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if (wdog_set_heartbeat(heartbeat)) {
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wdog_set_heartbeat(WD_TIMO);
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printk(KERN_INFO "bcm2708_wdog: heartbeat value must be "
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"0 < heartbeat < %d, using %d\n",
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WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET),
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WD_TIMO);
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}
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ret = register_reboot_notifier(&wdog_notifier);
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if (ret) {
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printk(KERN_ERR
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"wdt: cannot register reboot notifier (err=%d)\n", ret);
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goto out_reboot;
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}
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ret = misc_register(&wdog_miscdev);
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if (ret) {
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printk(KERN_ERR
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"wdt: cannot register miscdev on minor=%d (err=%d)\n",
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WATCHDOG_MINOR, ret);
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goto out_misc;
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}
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printk(KERN_INFO "bcm2708 watchdog, heartbeat=%d sec (nowayout=%d)\n",
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heartbeat, nowayout);
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return 0;
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out_misc:
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unregister_reboot_notifier(&wdog_notifier);
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out_reboot:
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return ret;
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}
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module_init(wdog_init);
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module_exit(wdog_exit);
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MODULE_AUTHOR("Luke Diamand");
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MODULE_DESCRIPTION("Driver for BCM2708 watchdog");
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MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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MODULE_ALIAS_MISCDEV(TEMP_MINOR);
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MODULE_LICENSE("GPL");
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Reference in New Issue
Block a user