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![Uwe Kleine-König](/assets/img/avatar_default.png)
The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is (mostly) ignored and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new() which already returns void. Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20230303213716.2123717-14-u.kleine-koenig@pengutronix.de Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
289 lines
6.3 KiB
C
289 lines
6.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* Watchdog timer for machines with the CS5535/CS5536 companion chip
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*
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* Copyright (C) 2006-2007, Advanced Micro Devices, Inc.
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* Copyright (C) 2009 Andres Salomon <dilinger@collabora.co.uk>
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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/miscdevice.h>
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#include <linux/watchdog.h>
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#include <linux/fs.h>
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#include <linux/platform_device.h>
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#include <linux/reboot.h>
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#include <linux/uaccess.h>
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#include <linux/cs5535.h>
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#define GEODEWDT_HZ 500
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#define GEODEWDT_SCALE 6
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#define GEODEWDT_MAX_SECONDS 131
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#define WDT_FLAGS_OPEN 1
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#define WDT_FLAGS_ORPHAN 2
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#define DRV_NAME "geodewdt"
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#define WATCHDOG_NAME "Geode GX/LX WDT"
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#define WATCHDOG_TIMEOUT 60
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static int timeout = WATCHDOG_TIMEOUT;
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module_param(timeout, int, 0);
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MODULE_PARM_DESC(timeout,
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"Watchdog timeout in seconds. 1<= timeout <=131, default="
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__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
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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,
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"Watchdog cannot be stopped once started (default="
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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static struct platform_device *geodewdt_platform_device;
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static unsigned long wdt_flags;
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static struct cs5535_mfgpt_timer *wdt_timer;
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static int safe_close;
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static void geodewdt_ping(void)
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{
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/* Stop the counter */
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cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, 0);
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/* Reset the counter */
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cs5535_mfgpt_write(wdt_timer, MFGPT_REG_COUNTER, 0);
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/* Enable the counter */
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cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, MFGPT_SETUP_CNTEN);
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}
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static void geodewdt_disable(void)
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{
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cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, 0);
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cs5535_mfgpt_write(wdt_timer, MFGPT_REG_COUNTER, 0);
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}
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static int geodewdt_set_heartbeat(int val)
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{
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if (val < 1 || val > GEODEWDT_MAX_SECONDS)
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return -EINVAL;
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cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, 0);
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cs5535_mfgpt_write(wdt_timer, MFGPT_REG_CMP2, val * GEODEWDT_HZ);
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cs5535_mfgpt_write(wdt_timer, MFGPT_REG_COUNTER, 0);
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cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, MFGPT_SETUP_CNTEN);
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timeout = val;
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return 0;
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}
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static int geodewdt_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(WDT_FLAGS_OPEN, &wdt_flags))
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return -EBUSY;
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if (!test_and_clear_bit(WDT_FLAGS_ORPHAN, &wdt_flags))
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__module_get(THIS_MODULE);
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geodewdt_ping();
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return stream_open(inode, file);
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}
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static int geodewdt_release(struct inode *inode, struct file *file)
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{
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if (safe_close) {
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geodewdt_disable();
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module_put(THIS_MODULE);
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} else {
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pr_crit("Unexpected close - watchdog is not stopping\n");
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geodewdt_ping();
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set_bit(WDT_FLAGS_ORPHAN, &wdt_flags);
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}
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clear_bit(WDT_FLAGS_OPEN, &wdt_flags);
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safe_close = 0;
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return 0;
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}
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static ssize_t geodewdt_write(struct file *file, const char __user *data,
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size_t len, loff_t *ppos)
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{
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if (len) {
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if (!nowayout) {
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size_t i;
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safe_close = 0;
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for (i = 0; i != len; i++) {
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char c;
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if (get_user(c, data + i))
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return -EFAULT;
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if (c == 'V')
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safe_close = 1;
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}
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}
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geodewdt_ping();
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}
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return len;
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}
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static long geodewdt_ioctl(struct file *file, unsigned int cmd,
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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 interval;
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static const struct watchdog_info ident = {
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING
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| WDIOF_MAGICCLOSE,
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.firmware_version = 1,
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.identity = WATCHDOG_NAME,
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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,
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sizeof(ident)) ? -EFAULT : 0;
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case WDIOC_GETSTATUS:
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case WDIOC_GETBOOTSTATUS:
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return put_user(0, p);
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case WDIOC_SETOPTIONS:
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{
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int options, ret = -EINVAL;
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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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geodewdt_disable();
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ret = 0;
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}
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if (options & WDIOS_ENABLECARD) {
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geodewdt_ping();
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ret = 0;
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}
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return ret;
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}
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case WDIOC_KEEPALIVE:
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geodewdt_ping();
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return 0;
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case WDIOC_SETTIMEOUT:
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if (get_user(interval, p))
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return -EFAULT;
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if (geodewdt_set_heartbeat(interval))
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return -EINVAL;
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fallthrough;
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case WDIOC_GETTIMEOUT:
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return put_user(timeout, p);
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default:
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return -ENOTTY;
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}
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return 0;
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}
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static const struct file_operations geodewdt_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = geodewdt_write,
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.unlocked_ioctl = geodewdt_ioctl,
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.compat_ioctl = compat_ptr_ioctl,
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.open = geodewdt_open,
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.release = geodewdt_release,
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};
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static struct miscdevice geodewdt_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &geodewdt_fops,
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};
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static int __init geodewdt_probe(struct platform_device *dev)
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{
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int ret;
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wdt_timer = cs5535_mfgpt_alloc_timer(MFGPT_TIMER_ANY, MFGPT_DOMAIN_WORKING);
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if (!wdt_timer) {
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pr_err("No timers were available\n");
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return -ENODEV;
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}
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/* Set up the timer */
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cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP,
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GEODEWDT_SCALE | (3 << 8));
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/* Set up comparator 2 to reset when the event fires */
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cs5535_mfgpt_toggle_event(wdt_timer, MFGPT_CMP2, MFGPT_EVENT_RESET, 1);
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/* Set up the initial timeout */
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cs5535_mfgpt_write(wdt_timer, MFGPT_REG_CMP2,
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timeout * GEODEWDT_HZ);
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ret = misc_register(&geodewdt_miscdev);
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return ret;
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}
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static void geodewdt_remove(struct platform_device *dev)
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{
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misc_deregister(&geodewdt_miscdev);
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}
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static void geodewdt_shutdown(struct platform_device *dev)
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{
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geodewdt_disable();
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}
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static struct platform_driver geodewdt_driver = {
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.remove_new = geodewdt_remove,
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.shutdown = geodewdt_shutdown,
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.driver = {
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.name = DRV_NAME,
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},
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};
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static int __init geodewdt_init(void)
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{
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int ret;
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geodewdt_platform_device = platform_device_register_simple(DRV_NAME,
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-1, NULL, 0);
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if (IS_ERR(geodewdt_platform_device))
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return PTR_ERR(geodewdt_platform_device);
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ret = platform_driver_probe(&geodewdt_driver, geodewdt_probe);
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if (ret)
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goto err;
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return 0;
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err:
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platform_device_unregister(geodewdt_platform_device);
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return ret;
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}
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static void __exit geodewdt_exit(void)
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{
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platform_device_unregister(geodewdt_platform_device);
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platform_driver_unregister(&geodewdt_driver);
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}
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module_init(geodewdt_init);
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module_exit(geodewdt_exit);
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MODULE_AUTHOR("Advanced Micro Devices, Inc");
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MODULE_DESCRIPTION("Geode GX/LX Watchdog Driver");
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MODULE_LICENSE("GPL");
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