+++ /dev/null
-/*
- * Watchdog driver for Freescale STMP37XX/STMP378X
- *
- * Author: Vitaly Wool <vital@embeddedalley.com>
- *
- * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
- * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/fs.h>
-#include <linux/miscdevice.h>
-#include <linux/watchdog.h>
-#include <linux/platform_device.h>
-#include <linux/spinlock.h>
-#include <linux/uaccess.h>
-#include <linux/module.h>
-
-#include <mach/platform.h>
-#include <mach/regs-rtc.h>
-
-#define DEFAULT_HEARTBEAT 19
-#define MAX_HEARTBEAT (0x10000000 >> 6)
-
-/* missing bitmask in headers */
-#define BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER 0x80000000
-
-#define WDT_IN_USE 0
-#define WDT_OK_TO_CLOSE 1
-
-#define WDOG_COUNTER_RATE 1000 /* 1 kHz clock */
-
-static DEFINE_SPINLOCK(stmp3xxx_wdt_io_lock);
-static unsigned long wdt_status;
-static const bool nowayout = WATCHDOG_NOWAYOUT;
-static int heartbeat = DEFAULT_HEARTBEAT;
-static unsigned long boot_status;
-
-static void wdt_enable(u32 value)
-{
- spin_lock(&stmp3xxx_wdt_io_lock);
- __raw_writel(value, REGS_RTC_BASE + HW_RTC_WATCHDOG);
- stmp3xxx_setl(BM_RTC_CTRL_WATCHDOGEN, REGS_RTC_BASE + HW_RTC_CTRL);
- stmp3xxx_setl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER,
- REGS_RTC_BASE + HW_RTC_PERSISTENT1);
- spin_unlock(&stmp3xxx_wdt_io_lock);
-}
-
-static void wdt_disable(void)
-{
- spin_lock(&stmp3xxx_wdt_io_lock);
- stmp3xxx_clearl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER,
- REGS_RTC_BASE + HW_RTC_PERSISTENT1);
- stmp3xxx_clearl(BM_RTC_CTRL_WATCHDOGEN, REGS_RTC_BASE + HW_RTC_CTRL);
- spin_unlock(&stmp3xxx_wdt_io_lock);
-}
-
-static void wdt_ping(void)
-{
- wdt_enable(heartbeat * WDOG_COUNTER_RATE);
-}
-
-static int stmp3xxx_wdt_open(struct inode *inode, struct file *file)
-{
- if (test_and_set_bit(WDT_IN_USE, &wdt_status))
- return -EBUSY;
-
- clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
- wdt_ping();
-
- return nonseekable_open(inode, file);
-}
-
-static ssize_t stmp3xxx_wdt_write(struct file *file, const char __user *data,
- size_t len, loff_t *ppos)
-{
- if (len) {
- if (!nowayout) {
- size_t i;
-
- clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
-
- for (i = 0; i != len; i++) {
- char c;
-
- if (get_user(c, data + i))
- return -EFAULT;
- if (c == 'V')
- set_bit(WDT_OK_TO_CLOSE, &wdt_status);
- }
- }
- wdt_ping();
- }
-
- return len;
-}
-
-static const struct watchdog_info ident = {
- .options = WDIOF_CARDRESET |
- WDIOF_MAGICCLOSE |
- WDIOF_SETTIMEOUT |
- WDIOF_KEEPALIVEPING,
- .identity = "STMP3XXX Watchdog",
-};
-
-static long stmp3xxx_wdt_ioctl(struct file *file, unsigned int cmd,
- unsigned long arg)
-{
- void __user *argp = (void __user *)arg;
- int __user *p = argp;
- int new_heartbeat, opts;
- int ret = -ENOTTY;
-
- switch (cmd) {
- case WDIOC_GETSUPPORT:
- ret = copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
- break;
-
- case WDIOC_GETSTATUS:
- ret = put_user(0, p);
- break;
-
- case WDIOC_GETBOOTSTATUS:
- ret = put_user(boot_status, p);
- break;
-
- case WDIOC_SETOPTIONS:
- if (get_user(opts, p)) {
- ret = -EFAULT;
- break;
- }
- if (opts & WDIOS_DISABLECARD)
- wdt_disable();
- else if (opts & WDIOS_ENABLECARD)
- wdt_ping();
- else {
- pr_debug("%s: unknown option 0x%x\n", __func__, opts);
- ret = -EINVAL;
- break;
- }
- ret = 0;
- break;
-
- case WDIOC_KEEPALIVE:
- wdt_ping();
- ret = 0;
- break;
-
- case WDIOC_SETTIMEOUT:
- if (get_user(new_heartbeat, p)) {
- ret = -EFAULT;
- break;
- }
- if (new_heartbeat <= 0 || new_heartbeat > MAX_HEARTBEAT) {
- ret = -EINVAL;
- break;
- }
-
- heartbeat = new_heartbeat;
- wdt_ping();
- /* Fall through */
-
- case WDIOC_GETTIMEOUT:
- ret = put_user(heartbeat, p);
- break;
- }
- return ret;
-}
-
-static int stmp3xxx_wdt_release(struct inode *inode, struct file *file)
-{
- int ret = 0;
-
- if (!nowayout) {
- if (!test_bit(WDT_OK_TO_CLOSE, &wdt_status)) {
- wdt_ping();
- pr_debug("%s: Device closed unexpectedly\n", __func__);
- ret = -EINVAL;
- } else {
- wdt_disable();
- clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
- }
- }
- clear_bit(WDT_IN_USE, &wdt_status);
-
- return ret;
-}
-
-static const struct file_operations stmp3xxx_wdt_fops = {
- .owner = THIS_MODULE,
- .llseek = no_llseek,
- .write = stmp3xxx_wdt_write,
- .unlocked_ioctl = stmp3xxx_wdt_ioctl,
- .open = stmp3xxx_wdt_open,
- .release = stmp3xxx_wdt_release,
-};
-
-static struct miscdevice stmp3xxx_wdt_miscdev = {
- .minor = WATCHDOG_MINOR,
- .name = "watchdog",
- .fops = &stmp3xxx_wdt_fops,
-};
-
-static int stmp3xxx_wdt_probe(struct platform_device *pdev)
-{
- int ret = 0;
-
- if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
- heartbeat = DEFAULT_HEARTBEAT;
-
- boot_status = __raw_readl(REGS_RTC_BASE + HW_RTC_PERSISTENT1) &
- BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER;
- boot_status = !!boot_status;
- stmp3xxx_clearl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER,
- REGS_RTC_BASE + HW_RTC_PERSISTENT1);
- wdt_disable(); /* disable for now */
-
- ret = misc_register(&stmp3xxx_wdt_miscdev);
- if (ret < 0) {
- dev_err(&pdev->dev, "cannot register misc device\n");
- return ret;
- }
-
- pr_info("initialized, heartbeat %d sec\n", heartbeat);
-
- return ret;
-}
-
-static int stmp3xxx_wdt_remove(struct platform_device *pdev)
-{
- misc_deregister(&stmp3xxx_wdt_miscdev);
- return 0;
-}
-
-#ifdef CONFIG_PM
-static int wdt_suspended;
-static u32 wdt_saved_time;
-
-static int stmp3xxx_wdt_suspend(struct platform_device *pdev,
- pm_message_t state)
-{
- if (__raw_readl(REGS_RTC_BASE + HW_RTC_CTRL) &
- BM_RTC_CTRL_WATCHDOGEN) {
- wdt_suspended = 1;
- wdt_saved_time = __raw_readl(REGS_RTC_BASE + HW_RTC_WATCHDOG);
- wdt_disable();
- }
- return 0;
-}
-
-static int stmp3xxx_wdt_resume(struct platform_device *pdev)
-{
- if (wdt_suspended) {
- wdt_enable(wdt_saved_time);
- wdt_suspended = 0;
- }
- return 0;
-}
-#else
-#define stmp3xxx_wdt_suspend NULL
-#define stmp3xxx_wdt_resume NULL
-#endif
-
-static struct platform_driver platform_wdt_driver = {
- .driver = {
- .name = "stmp3xxx_wdt",
- },
- .probe = stmp3xxx_wdt_probe,
- .remove = stmp3xxx_wdt_remove,
- .suspend = stmp3xxx_wdt_suspend,
- .resume = stmp3xxx_wdt_resume,
-};
-
-module_platform_driver(platform_wdt_driver);
-
-MODULE_DESCRIPTION("STMP3XXX Watchdog Driver");
-MODULE_LICENSE("GPL");
-
-module_param(heartbeat, int, 0);
-MODULE_PARM_DESC(heartbeat,
- "Watchdog heartbeat period in seconds from 1 to "
- __MODULE_STRING(MAX_HEARTBEAT) ", default "
- __MODULE_STRING(DEFAULT_HEARTBEAT));
-
-MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
projects / karo-tx-linux.git / commitdiff