+++ /dev/null
-/*
- * Blackfin On-Chip Watchdog Driver
- *
- * Originally based on softdog.c
- * Copyright 2006-2010 Analog Devices Inc.
- * Copyright 2006-2007 Michele d'Amico
- * Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>
- *
- * Enter bugs at http://blackfin.uclinux.org/
- *
- * Licensed under the GPL-2 or later.
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/platform_device.h>
-#include <linux/module.h>
-#include <linux/moduleparam.h>
-#include <linux/types.h>
-#include <linux/timer.h>
-#include <linux/miscdevice.h>
-#include <linux/watchdog.h>
-#include <linux/fs.h>
-#include <linux/init.h>
-#include <linux/interrupt.h>
-#include <linux/uaccess.h>
-#include <asm/blackfin.h>
-#include <asm/bfin_watchdog.h>
-
-#define stamp(fmt, args...) \
- pr_debug("%s:%i: " fmt "\n", __func__, __LINE__, ## args)
-#define stampit() stamp("here i am")
-
-#define WATCHDOG_NAME "bfin-wdt"
-
-/* The BF561 has two watchdogs (one per core), but since Linux
- * only runs on core A, we'll just work with that one.
- */
-#ifdef BF561_FAMILY
-# define bfin_read_WDOG_CTL() bfin_read_WDOGA_CTL()
-# define bfin_read_WDOG_CNT() bfin_read_WDOGA_CNT()
-# define bfin_read_WDOG_STAT() bfin_read_WDOGA_STAT()
-# define bfin_write_WDOG_CTL(x) bfin_write_WDOGA_CTL(x)
-# define bfin_write_WDOG_CNT(x) bfin_write_WDOGA_CNT(x)
-# define bfin_write_WDOG_STAT(x) bfin_write_WDOGA_STAT(x)
-#endif
-
-/* some defaults */
-#define WATCHDOG_TIMEOUT 20
-
-static unsigned int timeout = WATCHDOG_TIMEOUT;
-static bool nowayout = WATCHDOG_NOWAYOUT;
-static const struct watchdog_info bfin_wdt_info;
-static unsigned long open_check;
-static char expect_close;
-static DEFINE_SPINLOCK(bfin_wdt_spinlock);
-
-/**
- * bfin_wdt_keepalive - Keep the Userspace Watchdog Alive
- *
- * The Userspace watchdog got a KeepAlive: schedule the next timeout.
- */
-static int bfin_wdt_keepalive(void)
-{
- stampit();
- bfin_write_WDOG_STAT(0);
- return 0;
-}
-
-/**
- * bfin_wdt_stop - Stop the Watchdog
- *
- * Stops the on-chip watchdog.
- */
-static int bfin_wdt_stop(void)
-{
- stampit();
- bfin_write_WDOG_CTL(WDEN_DISABLE);
- return 0;
-}
-
-/**
- * bfin_wdt_start - Start the Watchdog
- *
- * Starts the on-chip watchdog. Automatically loads WDOG_CNT
- * into WDOG_STAT for us.
- */
-static int bfin_wdt_start(void)
-{
- stampit();
- bfin_write_WDOG_CTL(WDEN_ENABLE | ICTL_RESET);
- return 0;
-}
-
-/**
- * bfin_wdt_running - Check Watchdog status
- *
- * See if the watchdog is running.
- */
-static int bfin_wdt_running(void)
-{
- stampit();
- return ((bfin_read_WDOG_CTL() & WDEN_MASK) != WDEN_DISABLE);
-}
-
-/**
- * bfin_wdt_set_timeout - Set the Userspace Watchdog timeout
- * @t: new timeout value (in seconds)
- *
- * Translate the specified timeout in seconds into System Clock
- * terms which is what the on-chip Watchdog requires.
- */
-static int bfin_wdt_set_timeout(unsigned long t)
-{
- u32 cnt, max_t, sclk;
- unsigned long flags;
-
- sclk = get_sclk();
- max_t = -1 / sclk;
- cnt = t * sclk;
- stamp("maxtimeout=%us newtimeout=%lus (cnt=%#x)", max_t, t, cnt);
-
- if (t > max_t) {
- pr_warn("timeout value is too large\n");
- return -EINVAL;
- }
-
- spin_lock_irqsave(&bfin_wdt_spinlock, flags);
- {
- int run = bfin_wdt_running();
- bfin_wdt_stop();
- bfin_write_WDOG_CNT(cnt);
- if (run)
- bfin_wdt_start();
- }
- spin_unlock_irqrestore(&bfin_wdt_spinlock, flags);
-
- timeout = t;
-
- return 0;
-}
-
-/**
- * bfin_wdt_open - Open the Device
- * @inode: inode of device
- * @file: file handle of device
- *
- * Watchdog device is opened and started.
- */
-static int bfin_wdt_open(struct inode *inode, struct file *file)
-{
- stampit();
-
- if (test_and_set_bit(0, &open_check))
- return -EBUSY;
-
- if (nowayout)
- __module_get(THIS_MODULE);
-
- bfin_wdt_keepalive();
- bfin_wdt_start();
-
- return nonseekable_open(inode, file);
-}
-
-/**
- * bfin_wdt_close - Close the Device
- * @inode: inode of device
- * @file: file handle of device
- *
- * Watchdog device is closed and stopped.
- */
-static int bfin_wdt_release(struct inode *inode, struct file *file)
-{
- stampit();
-
- if (expect_close == 42)
- bfin_wdt_stop();
- else {
- pr_crit("Unexpected close, not stopping watchdog!\n");
- bfin_wdt_keepalive();
- }
- expect_close = 0;
- clear_bit(0, &open_check);
- return 0;
-}
-
-/**
- * bfin_wdt_write - Write to Device
- * @file: file handle of device
- * @buf: buffer to write
- * @count: length of buffer
- * @ppos: offset
- *
- * Pings the watchdog on write.
- */
-static ssize_t bfin_wdt_write(struct file *file, const char __user *data,
- size_t len, loff_t *ppos)
-{
- stampit();
-
- 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;
- }
- }
- bfin_wdt_keepalive();
- }
-
- return len;
-}
-
-/**
- * bfin_wdt_ioctl - Query Device
- * @file: file handle of device
- * @cmd: watchdog command
- * @arg: argument
- *
- * Query basic information from the device or ping it, as outlined by the
- * watchdog API.
- */
-static long bfin_wdt_ioctl(struct file *file,
- unsigned int cmd, unsigned long arg)
-{
- void __user *argp = (void __user *)arg;
- int __user *p = argp;
-
- stampit();
-
- switch (cmd) {
- case WDIOC_GETSUPPORT:
- if (copy_to_user(argp, &bfin_wdt_info, sizeof(bfin_wdt_info)))
- return -EFAULT;
- else
- return 0;
- case WDIOC_GETSTATUS:
- case WDIOC_GETBOOTSTATUS:
- return put_user(!!(_bfin_swrst & SWRST_RESET_WDOG), p);
- case WDIOC_SETOPTIONS: {
- unsigned long flags;
- int options, ret = -EINVAL;
-
- if (get_user(options, p))
- return -EFAULT;
-
- spin_lock_irqsave(&bfin_wdt_spinlock, flags);
- if (options & WDIOS_DISABLECARD) {
- bfin_wdt_stop();
- ret = 0;
- }
- if (options & WDIOS_ENABLECARD) {
- bfin_wdt_start();
- ret = 0;
- }
- spin_unlock_irqrestore(&bfin_wdt_spinlock, flags);
- return ret;
- }
- case WDIOC_KEEPALIVE:
- bfin_wdt_keepalive();
- return 0;
- case WDIOC_SETTIMEOUT: {
- int new_timeout;
-
- if (get_user(new_timeout, p))
- return -EFAULT;
- if (bfin_wdt_set_timeout(new_timeout))
- return -EINVAL;
- }
- /* Fall */
- case WDIOC_GETTIMEOUT:
- return put_user(timeout, p);
- default:
- return -ENOTTY;
- }
-}
-
-#ifdef CONFIG_PM
-static int state_before_suspend;
-
-/**
- * bfin_wdt_suspend - suspend the watchdog
- * @pdev: device being suspended
- * @state: requested suspend state
- *
- * Remember if the watchdog was running and stop it.
- * TODO: is this even right? Doesn't seem to be any
- * standard in the watchdog world ...
- */
-static int bfin_wdt_suspend(struct platform_device *pdev, pm_message_t state)
-{
- stampit();
-
- state_before_suspend = bfin_wdt_running();
- bfin_wdt_stop();
-
- return 0;
-}
-
-/**
- * bfin_wdt_resume - resume the watchdog
- * @pdev: device being resumed
- *
- * If the watchdog was running, turn it back on.
- */
-static int bfin_wdt_resume(struct platform_device *pdev)
-{
- stampit();
-
- if (state_before_suspend) {
- bfin_wdt_set_timeout(timeout);
- bfin_wdt_start();
- }
-
- return 0;
-}
-#else
-# define bfin_wdt_suspend NULL
-# define bfin_wdt_resume NULL
-#endif
-
-static const struct file_operations bfin_wdt_fops = {
- .owner = THIS_MODULE,
- .llseek = no_llseek,
- .write = bfin_wdt_write,
- .unlocked_ioctl = bfin_wdt_ioctl,
- .open = bfin_wdt_open,
- .release = bfin_wdt_release,
-};
-
-static struct miscdevice bfin_wdt_miscdev = {
- .minor = WATCHDOG_MINOR,
- .name = "watchdog",
- .fops = &bfin_wdt_fops,
-};
-
-static const struct watchdog_info bfin_wdt_info = {
- .identity = "Blackfin Watchdog",
- .options = WDIOF_SETTIMEOUT |
- WDIOF_KEEPALIVEPING |
- WDIOF_MAGICCLOSE,
-};
-
-/**
- * bfin_wdt_probe - Initialize module
- *
- * Registers the misc device. Actual device
- * initialization is handled by bfin_wdt_open().
- */
-static int bfin_wdt_probe(struct platform_device *pdev)
-{
- int ret;
-
- ret = misc_register(&bfin_wdt_miscdev);
- if (ret) {
- pr_err("cannot register miscdev on minor=%d (err=%d)\n",
- WATCHDOG_MINOR, ret);
- return ret;
- }
-
- pr_info("initialized: timeout=%d sec (nowayout=%d)\n",
- timeout, nowayout);
-
- return 0;
-}
-
-/**
- * bfin_wdt_remove - Initialize module
- *
- * Unregisters the misc device. Actual device
- * deinitialization is handled by bfin_wdt_close().
- */
-static int bfin_wdt_remove(struct platform_device *pdev)
-{
- misc_deregister(&bfin_wdt_miscdev);
- return 0;
-}
-
-/**
- * bfin_wdt_shutdown - Soft Shutdown Handler
- *
- * Handles the soft shutdown event.
- */
-static void bfin_wdt_shutdown(struct platform_device *pdev)
-{
- stampit();
-
- bfin_wdt_stop();
-}
-
-static struct platform_device *bfin_wdt_device;
-
-static struct platform_driver bfin_wdt_driver = {
- .probe = bfin_wdt_probe,
- .remove = bfin_wdt_remove,
- .shutdown = bfin_wdt_shutdown,
- .suspend = bfin_wdt_suspend,
- .resume = bfin_wdt_resume,
- .driver = {
- .name = WATCHDOG_NAME,
- },
-};
-
-/**
- * bfin_wdt_init - Initialize module
- *
- * Checks the module params and registers the platform device & driver.
- * Real work is in the platform probe function.
- */
-static int __init bfin_wdt_init(void)
-{
- int ret;
-
- stampit();
-
- /* Check that the timeout value is within range */
- if (bfin_wdt_set_timeout(timeout))
- return -EINVAL;
-
- /* Since this is an on-chip device and needs no board-specific
- * resources, we'll handle all the platform device stuff here.
- */
- ret = platform_driver_register(&bfin_wdt_driver);
- if (ret) {
- pr_err("unable to register driver\n");
- return ret;
- }
-
- bfin_wdt_device = platform_device_register_simple(WATCHDOG_NAME,
- -1, NULL, 0);
- if (IS_ERR(bfin_wdt_device)) {
- pr_err("unable to register device\n");
- platform_driver_unregister(&bfin_wdt_driver);
- return PTR_ERR(bfin_wdt_device);
- }
-
- return 0;
-}
-
-/**
- * bfin_wdt_exit - Deinitialize module
- *
- * Back out the platform device & driver steps. Real work is in the
- * platform remove function.
- */
-static void __exit bfin_wdt_exit(void)
-{
- platform_device_unregister(bfin_wdt_device);
- platform_driver_unregister(&bfin_wdt_driver);
-}
-
-module_init(bfin_wdt_init);
-module_exit(bfin_wdt_exit);
-
-MODULE_AUTHOR("Michele d'Amico, Mike Frysinger <vapier@gentoo.org>");
-MODULE_DESCRIPTION("Blackfin Watchdog Device Driver");
-MODULE_LICENSE("GPL");
-
-module_param(timeout, uint, 0);
-MODULE_PARM_DESC(timeout,
- "Watchdog timeout in seconds. (1<=timeout<=((2^32)/SCLK), default="
- __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
-
-module_param(nowayout, bool, 0);
-MODULE_PARM_DESC(nowayout,
- "Watchdog cannot be stopped once started (default="
- __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
projects / mirror_ubuntu-disco-kernel.git / commitdiff