+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Watchdog driver for Kendin/Micrel KS8695.
- *
- * (C) 2007 Andrew Victor
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/bitops.h>
-#include <linux/errno.h>
-#include <linux/fs.h>
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/miscdevice.h>
-#include <linux/module.h>
-#include <linux/moduleparam.h>
-#include <linux/platform_device.h>
-#include <linux/types.h>
-#include <linux/watchdog.h>
-#include <linux/io.h>
-#include <linux/uaccess.h>
-#include <mach/hardware.h>
-
-#define KS8695_TMR_OFFSET (0xF0000 + 0xE400)
-#define KS8695_TMR_VA (KS8695_IO_VA + KS8695_TMR_OFFSET)
-
-/*
- * Timer registers
- */
-#define KS8695_TMCON (0x00) /* Timer Control Register */
-#define KS8695_T0TC (0x08) /* Timer 0 Timeout Count Register */
-#define TMCON_T0EN (1 << 0) /* Timer 0 Enable */
-
-/* Timer0 Timeout Counter Register */
-#define T0TC_WATCHDOG (0xff) /* Enable watchdog mode */
-
-#define WDT_DEFAULT_TIME 5 /* seconds */
-#define WDT_MAX_TIME 171 /* seconds */
-
-static int wdt_time = WDT_DEFAULT_TIME;
-static bool nowayout = WATCHDOG_NOWAYOUT;
-
-module_param(wdt_time, int, 0);
-MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default="
- __MODULE_STRING(WDT_DEFAULT_TIME) ")");
-
-#ifdef CONFIG_WATCHDOG_NOWAYOUT
-module_param(nowayout, bool, 0);
-MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
- __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
-#endif
-
-
-static unsigned long ks8695wdt_busy;
-static DEFINE_SPINLOCK(ks8695_lock);
-
-/* ......................................................................... */
-
-/*
- * Disable the watchdog.
- */
-static inline void ks8695_wdt_stop(void)
-{
- unsigned long tmcon;
-
- spin_lock(&ks8695_lock);
- /* disable timer0 */
- tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
- __raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
- spin_unlock(&ks8695_lock);
-}
-
-/*
- * Enable and reset the watchdog.
- */
-static inline void ks8695_wdt_start(void)
-{
- unsigned long tmcon;
- unsigned long tval = wdt_time * KS8695_CLOCK_RATE;
-
- spin_lock(&ks8695_lock);
- /* disable timer0 */
- tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
- __raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
-
- /* program timer0 */
- __raw_writel(tval | T0TC_WATCHDOG, KS8695_TMR_VA + KS8695_T0TC);
-
- /* re-enable timer0 */
- tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
- __raw_writel(tmcon | TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
- spin_unlock(&ks8695_lock);
-}
-
-/*
- * Reload the watchdog timer. (ie, pat the watchdog)
- */
-static inline void ks8695_wdt_reload(void)
-{
- unsigned long tmcon;
-
- spin_lock(&ks8695_lock);
- /* disable, then re-enable timer0 */
- tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
- __raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
- __raw_writel(tmcon | TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
- spin_unlock(&ks8695_lock);
-}
-
-/*
- * Change the watchdog time interval.
- */
-static int ks8695_wdt_settimeout(int new_time)
-{
- /*
- * All counting occurs at KS8695_CLOCK_RATE / 128 = 0.256 Hz
- *
- * Since WDV is a 16-bit counter, the maximum period is
- * 65536 / 0.256 = 256 seconds.
- */
- if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
- return -EINVAL;
-
- /* Set new watchdog time. It will be used when
- ks8695_wdt_start() is called. */
- wdt_time = new_time;
- return 0;
-}
-
-/* ......................................................................... */
-
-/*
- * Watchdog device is opened, and watchdog starts running.
- */
-static int ks8695_wdt_open(struct inode *inode, struct file *file)
-{
- if (test_and_set_bit(0, &ks8695wdt_busy))
- return -EBUSY;
-
- ks8695_wdt_start();
- return stream_open(inode, file);
-}
-
-/*
- * Close the watchdog device.
- * If CONFIG_WATCHDOG_NOWAYOUT is NOT defined then the watchdog is also
- * disabled.
- */
-static int ks8695_wdt_close(struct inode *inode, struct file *file)
-{
- /* Disable the watchdog when file is closed */
- if (!nowayout)
- ks8695_wdt_stop();
- clear_bit(0, &ks8695wdt_busy);
- return 0;
-}
-
-static const struct watchdog_info ks8695_wdt_info = {
- .identity = "ks8695 watchdog",
- .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
-};
-
-/*
- * Handle commands from user-space.
- */
-static long ks8695_wdt_ioctl(struct file *file, unsigned int cmd,
- unsigned long arg)
-{
- void __user *argp = (void __user *)arg;
- int __user *p = argp;
- int new_value;
-
- switch (cmd) {
- case WDIOC_GETSUPPORT:
- return copy_to_user(argp, &ks8695_wdt_info,
- sizeof(ks8695_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)
- ks8695_wdt_stop();
- if (new_value & WDIOS_ENABLECARD)
- ks8695_wdt_start();
- return 0;
- case WDIOC_KEEPALIVE:
- ks8695_wdt_reload(); /* pat the watchdog */
- return 0;
- case WDIOC_SETTIMEOUT:
- if (get_user(new_value, p))
- return -EFAULT;
- if (ks8695_wdt_settimeout(new_value))
- return -EINVAL;
- /* Enable new time value */
- ks8695_wdt_start();
- /* Return current value */
- return put_user(wdt_time, p);
- case WDIOC_GETTIMEOUT:
- return put_user(wdt_time, p);
- default:
- return -ENOTTY;
- }
-}
-
-/*
- * Pat the watchdog whenever device is written to.
- */
-static ssize_t ks8695_wdt_write(struct file *file, const char *data,
- size_t len, loff_t *ppos)
-{
- ks8695_wdt_reload(); /* pat the watchdog */
- return len;
-}
-
-/* ......................................................................... */
-
-static const struct file_operations ks8695wdt_fops = {
- .owner = THIS_MODULE,
- .llseek = no_llseek,
- .unlocked_ioctl = ks8695_wdt_ioctl,
- .open = ks8695_wdt_open,
- .release = ks8695_wdt_close,
- .write = ks8695_wdt_write,
-};
-
-static struct miscdevice ks8695wdt_miscdev = {
- .minor = WATCHDOG_MINOR,
- .name = "watchdog",
- .fops = &ks8695wdt_fops,
-};
-
-static int ks8695wdt_probe(struct platform_device *pdev)
-{
- int res;
-
- if (ks8695wdt_miscdev.parent)
- return -EBUSY;
- ks8695wdt_miscdev.parent = &pdev->dev;
-
- res = misc_register(&ks8695wdt_miscdev);
- if (res)
- return res;
-
- pr_info("KS8695 Watchdog Timer enabled (%d seconds%s)\n",
- wdt_time, nowayout ? ", nowayout" : "");
- return 0;
-}
-
-static int ks8695wdt_remove(struct platform_device *pdev)
-{
- misc_deregister(&ks8695wdt_miscdev);
- ks8695wdt_miscdev.parent = NULL;
-
- return 0;
-}
-
-static void ks8695wdt_shutdown(struct platform_device *pdev)
-{
- ks8695_wdt_stop();
-}
-
-#ifdef CONFIG_PM
-
-static int ks8695wdt_suspend(struct platform_device *pdev, pm_message_t message)
-{
- ks8695_wdt_stop();
- return 0;
-}
-
-static int ks8695wdt_resume(struct platform_device *pdev)
-{
- if (ks8695wdt_busy)
- ks8695_wdt_start();
- return 0;
-}
-
-#else
-#define ks8695wdt_suspend NULL
-#define ks8695wdt_resume NULL
-#endif
-
-static struct platform_driver ks8695wdt_driver = {
- .probe = ks8695wdt_probe,
- .remove = ks8695wdt_remove,
- .shutdown = ks8695wdt_shutdown,
- .suspend = ks8695wdt_suspend,
- .resume = ks8695wdt_resume,
- .driver = {
- .name = "ks8695_wdt",
- },
-};
-
-static int __init ks8695_wdt_init(void)
-{
- /* Check that the heartbeat value is within range;
- if not reset to the default */
- if (ks8695_wdt_settimeout(wdt_time)) {
- ks8695_wdt_settimeout(WDT_DEFAULT_TIME);
- pr_info("ks8695_wdt: wdt_time value must be 1 <= wdt_time <= %i"
- ", using %d\n", wdt_time, WDT_MAX_TIME);
- }
- return platform_driver_register(&ks8695wdt_driver);
-}
-
-static void __exit ks8695_wdt_exit(void)
-{
- platform_driver_unregister(&ks8695wdt_driver);
-}
-
-module_init(ks8695_wdt_init);
-module_exit(ks8695_wdt_exit);
-
-MODULE_AUTHOR("Andrew Victor");
-MODULE_DESCRIPTION("Watchdog driver for KS8695");
-MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:ks8695_wdt");
projects / platform / kernel / linux-rpi.git / commitdiff